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WDEN . MAINZ . PENNSYLVANIA in association with UNIVERSAL EDITION LONDON .ANTON WEBERN THE PATH TO THE NEW MUSIC Edited by Willi Reich THEODORE PRESSER COMPANY BRYN MAWR. ZURICH .
All rights No part of this publication may be translated or strictly reserved in all countries. English Edition Copyright 1963 by Theodore Presser Co. Vienna Original German Edition Copyright I960 by Universal Edition A.Cover design : Willi Bahner. Pennsylvania.. reproduced without the consent of the publishers. Wien. ^ .G..
The Path to Twelve-Note Composition 42 Postscript 57 Translated by Leo Black ..CONTENTS Page Preface 7 Tlie Path to the New Music.
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The latter is its usual meaning in these lectures. and also the cohesion or unity brought about by these connections.TRANSLATOR'S PREFACE has been used. ** Note ".B. perhaps apologies are due to American and German readers who would have preferred "tone ". and here Zusammenhange ** " fc * : L. " Unity "= Zusammenhang **. The translator's resolve to adhere to the " Die Reihe English form was strengthened by the consideration that in *% to which this volume is in a sense a companion. form '% ** structure " and content " " for the sake of consistency the ugly but literal shape has been used. but at the end of the second series Webern even " " refers to "unities" was clearly impossible. " tone " is frequently used with its specific English meaning of a pure impulse devoid of overtones. relation" relatedness '% ships between entities or parts of the same entity. The German can imply both connections. " " Shape = "Gestalt". . " At different points the word could ** have been " " ** translated as feature '% idea **. connections : A note on some frequently-occurring terms may be appropriate.
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Not until long after the war and Webern's tragic end could I go was then through the archives of the periodical. who was very characteristic that Webera should have called both cycles paths. as were frequent long pauses and deep intakes of breath.PREFACE unnecessary to justify publication of the sixteen lectures given by Webern and 1933 in a private house in Vienna. The extraordinary brevity of some of the texts. Here the chronological order of the two cycles of eight lectures has been reversed. It is He. We wanted to print them verbatim in the musical periodical 23 ". before an audience paying a small entrance fee. which were safe in Switzerland. what does need explaining is the long delay in publishing them." " always under way. for objective reasons that will immediately be obvious. Universal Edition at once agreed gladly to my proposal that the lectures should now be published. and thus of his wonderful and pure personality. My friend Dr. and it that Ploderer's transcripts. is explained by the fact that on those evenings Webern spoke less and played whole works or individual movements on the piano instead. The occasional repetitions were used quite consciously by Webern to intensify and heighten his remarks. In this way there is a natural progression from the elementary ideas treated in 1933 to the complex circumstances of twelve-note music sketched in 1932. only a few obvious stenographic errors have been corrected. which was the result of unusual circumstances. But the periodical's small circulation It is early in 1932 temporarily prevented their publication. a Viennese lawyer who took his own life in September 1933. and later their sharp attacks on the cultural politics of the Nazis would have exposed Webern to serious consequences. which I published in Vienna at that time. also came to light. In this form they offer not only their own valuable contents but also a highly life-like idea of Webern's curiously drastic. which reconciled high erudition and the keenest artistic thinking with an almost child-like expression of feeling. Rudolf Ploderer. was also a close personal friend of Webern. and took down the lectures in short" hand. particularly from the 1932 cycle. First ** . They are here reprinted exactly according to the shorthand notes. unforced way of talking. All this was an essential factor in the unprecedented urgency of his lectures and the shattering impression they made on all their listeners. already quite yellow with age." wanted to show others the way too.
Everything arbitrary or illusory falls away: here is necessity. " wants to express. and removed from all human arbitrariness. Goethe's remark about the art of antiquity. These lectures are handed down to posterity as a reflection of those experiences as a token of gratitude for all the beauty and profundity he gave us by precept and example. but only for those " equipped with creation. And this leads us to the view that the things " " aesthetic but are determined by natural treated by art in general are not laws. he would then reveal the law governing the onward course of what was at present new. also follows " the same line: These high works of art were at the same time brought forth as humanity's highest works of nature." is Here Webern adopted Goethe's view. let him hear! there controlled . according to true and natural laws." " he wanted to show what had at various times over the centuries been new in music. He wants to smooth the way to the great masters of music. we must strive to discover the laws according to which nature. tends to produce and does produce when she can. in the particular form of human nature. in its particular " form man ". as documentation of his lofty spirit. meaning that it had never been said before. as a monument to his noble humanity. here is God. Just as the researcher nature in general into nature strives to discover the rules of order that are the basis of nature. It could be a matter only of to which nature in general. Free fantasy of that kind can only be countered by saying that not a word here which Webern did not himself speak. which Webern quotes. in the fiery yet way that made each meeting with him an unforgettable experience. He who has ears to hear." Man is only the vessel into which poured what *' Just as Goethe defines the essence of colour as natural law as related to the sense of sight." Webern wants to see sound appreciated as natural law in relation to the sense of hearing. and that all discussion of art can only take place along these lines. which he explained with copious " getting to know the laws according quotation. Willi Reich . From the laws that resulted in the course of this. is productive. this realisation and with reverence for the secret of artistic The musical of Webern's is literature of recent years may have given many readers an idea spiritual personality quite different from the one that emerges from these lectures.
for people not professionally con- cerned with music. what is the value. started so late I begin by outlining my plan. A Fackel "=" Torch. which affects both language and speech. for laymen. it's immensely important and we must clearly be agreed about it that it would be foolish to set about dealing with this material. the material that they are constantly using. so to speak. and we can treat this as a starting point. of getting involved with these disciplines that are self-evident to the musician? What value can it have? Here I want to refer to Karl Kraus' essay on language in the last issue of Die Fackel.THE PATH TO THE NEW MUSIC I think we go about it this way was originally it eight times to discuss things. but it is all the same. as if the value involved were aesthetic. which we handle from our earliest years. " Here is Karl Kraus: The practical application of the theory. what is the point. From 1911 onward Karl Kraus wrote all of it himself. so long as they are alive " In the last sentence he even says about language." . at the risk of boring the nothing I can do about that. then. What he says is that our concern with language and the secrets of language would be a moral gain. This guarantee of a moral gain lies in a spiritual discipline which ensures the learn to serve her!" * ' Viennese periodical published by Karl Kraus. I want to take as broad a view as possible and my first question will be this. Karl Kraus says in this essay how important it would be for people to be at " home with and able to talk."* Everything in it can be taken literally as applying to music. As it has all to last three months we shall be meeting I expect many of you have no professional contact with music. and with it the sphere whose riches lie beyond what is tangibly useful. But perhaps they will be interested. would never be that he who learns to speak should also learn the language. not language. I want my lectures to take these " " there's better-informed people into account. Not. but that he should approach a grasp of the wordshape. too. We must say the same! We are here to talk about music. and that I should talk to you as laymen. it first appeared in 1899 and existed for over thirty years. for a layman (of course I take for granted that musicians already know it all) so. because we want to be artistic snobs and dilettantes. Let man Kraus says and note this very carefully.
and which are convincing.. can only aim at proving these rules to some extent. in a broader context. . In the introduction to his Theory of Colour. Nothing would be more foolish than to suppose that the need awakened or satisfied in striving after perfection of language is " It is better to an aesthetic one. these elements." So it goes on. I quote them so that we shall be at one about our basic assumptions.. You see. That is to say. it does " not come about as I want to paint a beautiful picture. that happens toobut it's not art. the plans behind her pitfalls." Goethe speaks aphoristically ** of the impossibility of accounting for beauty in nature and art . We want to sense laws . one would have to know them.utmost responsibility toward the only thing there is no penalty for injuring for all language and which is more suited than anything else to teach respect the other values in life . that in itself will have achieved something positive." But Goethe sees this as almost impossible but that doesn't make it less of a necessity " to get to know the laws according to which nature in general. that what we regard as and call a work of art is basically nothing but a product of nature in general. in the particular form of human nature. but that it is all the same. *' What was that? Goethe sees art as a product of nature in general. to be spiritually I involved! Now do you begin to see what What we of music.. Here I want to quote to you some wonderful lines by Goethe.. ladies and gentlemen. What is this "nature in general?" Perhaps what we see around us? But what does that mean? It is an explanation of human productivity." Now 10 . with the riddles behind their rules?" Just this: to teach them to see chasms in truisms! And that would be salvation . to me at least.. and based on rules of order. or I'm getting at? discuss should help you to find a means of getting to the bottom let us say the only point of occupying yourselves in this way is to get an inkling of what goes on in music. there is no essential contrast between a product of nature and a product of art." And so that we do not imagine we can learn to command: "To teach people to see chasms in truisms that would be the teacher's duty toward a sinful generation. poem." " What value can there be in laymen getting involved with said earlier.. and.. you're able to look at certain manifestations in present-day music with a little more awareness and critical appreciation. than of commanding her. which we shall be carrying out." . what it is. what art of any kind is. sentence after sentence! dream of plumbing the riddles behind her rules. particularly of genius. And if. write a beautiful and so on and so forth. which could not be more general. taking the particular form human nature. Yes. which must be fundamental to all the things we shall discuss. tends to produce and does produce when she can .. Perhaps for the moment is therefore music too. I prefer to speak quite generally and say all art. and our whole investigation of this material. when I've drawn your attention to various things.
we must strive to discover the laws according to which nature. To put it more plainly. He spoke of the art of antiquity: These high works of art were at the same time brought forth as humanity's highest works of nature. here is necessity. What I mean by that must be clear to you from those Goethe sentences. at the mystery they contain. No trace of arbitrariness! Nothing illusory! And I must quote still another " passage from Goethe. Basically this is the same as colour and what I have said about it. Perhaps that's enough for the moment to show you my point of view and to convince you that things are really like that. that music is natural law as related to the sense of hearing. here is God. It's natural that when one approaches and looks at and observes great works of art." Since the difference between colour and music is one of degree." but that it is a matter of natural laws. But some of them have already been our craftsman's method. whether as believer or unbeliever. not of kind. about music: hi the craftsman's if he is to be capable Another quotation from Goethe." is productive. man is only the vessel into which is poured what "nature in " wants to express. imagines. You know Goethe wrote a Theory of Colour ". believing. with which art has to do. in the same way one has to approach works of nature. " in its particular form man.. we have not yet even given a definite explanation of what colour in fact is . But it is surely the truth. one can say that music is natural law as related to the sense of hearing. are not " aesthetic. specific and applied in what I like to call To be method with which the musician must concern himself of producing something genuine. which is why I say that if we are to discuss music here we can only do it while recognising. recognised. Everything arbitrary or illusory falls " " away. he tries to fathom why it is that everything has a colour. because it expresses our line of thought " so wonderfully.. We shall again have to strive to pin down what is necessity in the great masterpieces. one thing must be clear to us 11 . Here again there is nothing left but to repeat: colour is natural law as related to the sense of sight. more's the pity.. and probably not all of them are in fact discoverable. with the necessary awe at the secrets they are based on..And the works that endure and will endure for ever. according to true and natural laws. Here laws exist. one must approach them. and so on . And he " But perhaps those of a more orderly turn of mind will point out that says. And this leads us to the view that the things treated by art in general. You see I would put it something like this: just general a researcher into nature strives to discover the rules of order that are the as basis of nature." Humanity's works of nature the same idea! And something else emerges here: necessity. that all discussion of music can only take place along these lines. But whether we have yet recognised it or not. cannot have come into being as humanity. the great masterpieces.
To speak more man concretely: whence does this system of sound come. in fact. You know that every note is accompanied by its overtones an infinite number. The note. namely. that we cannot conceive these laws differently from the laws we attribute to nature. a word about the title of my lectures. so How everything that has developed since the days of Greek music up to our own time Western music uses certain scales which have taken on particular forms. music that appears as something never said before. then in the next octave the third. As you know. and it's remarkable to see how man has made use of this phenomenon for his immediate needs before he can produce a musical shape how he has used this thing of mystery. in referring to Goethe's views. I must get down to practical matters and treat something of a more general. So new music would be what happened a thousand years ago. natural law as related to the sense of hearing. which uses wherever musical works exist? has it come about? Now. I don't know whether this is so well known to you all. "The path to the new music. So * " Style Neue und veraltete Musik oder Stil und Gedanke " (New and Obsolete Music or and Idea). How did these scales come about? They are really a manifestation of the overtone series. is today So we want to fathom the hidden natural laws in order to see more clearly what is going on today. new music is that which has never been said. because otherwise we shall misunderstand each other and because it follows directly on what we said earlier. but musical nature. touch on something quite general." Were any of you at Schoenberg's lecture?* He. but I should like to discuss it with you: how did what we call music come about? How have men used what Nature provided? You know that a note isn't a simple thing. This implies that the latter note has the same relationship with the one a fifth lower. Then we shall have covered the path to the new music. then the church modes of bygone ages.that rules of order prevail here. the octave comes first." And perhaps then we shall know what new music and what obsolete music is. that is to say it has the strongest affinity with the tonic. then the fifth. spoke of "New music. know of the Greek modes." What did he mean by that? Did he want to show the path to modern music? My own remarks take on a double significance when related to Schoenberg's remarks. but something complex. what new music really is. isn't it? So already we ought really to start looking here for rules or order. Western music mean We sive note. Enough of talking about art let's Now talk about nature! is What the material of music? . and for the ways the rules of order manifest themselves. . What is quite clear here? That the fifth is the first obtruI far as we know. given by Schoenberg to the Vienna Kulturbund in January 1933. just as much as what is happening Now now. the seventh. 12 . . too. But we can " follow the course of things through the centuries and we shall see also say. and if you go on.
only intellectual and philosophical. yet he made the stupidest possible judgment he preferred Rossini to Mozart! When a contemporary is concerned." Again. I don't mean the broad masses. so as to see ever more clearly. " " In Parsifal Wagner switched to different spiritual territory. corresponding to a musical shape. We shall try to work things out among Last time " ourselves. equilibrium there is a balance between the forces pulling upwards and downwards. parallelogram of forces. Wagner was not musical. You scale I don't understand Japanese and Chinese music. I want to take a look at blunders by great minds! You'll have noticed already what a remarkable attitude to His ideas about music were unmusic Schopenhauer had. Goethe. " out from Karl Kraus' (he could also have word-shape " " said or linguistic form linguistic shape "). precedented. for example. blunders are easier to forgive but he was dealing with things long past a historical error. Goethe's famous meeting with Beethoven was certainly not as it's usually described. he was not a "crazy fool. to show how important it is to treat all this. all illustrious names! Nietzsche again. we set " if Here I want to digress a little. not our seven-note one. Our seven-note can be explained in this way. (February 20th. when they are not an imitation of our music. Nietzsche! his temper. So we get beyond material and arrive at a grasp of musical ideas. one is to appreciate musical ideas. who haven't much time for things of the mind. It's quite remarkable how few people are capable of grasping a musical idea. for example. So the overtones of the three closely neighbouring and closely related notes contain the seven notes of the scale. Nietzsche. here we have a kind of G see: as a material it accords completely with nature. Goethewhat did he like? Zelter! Schubert sends him the "Erl-King" he doesn't even look at it. for Beethoven knew his " way about in society very well. and Nietzsche his contact with 13 . in fact! And again. I should like it to be our practice that each time someone should give a brief summary of what we discussed last time. But the special consistency and firm basis of our system seem proved by the fact that our music has been assigned a special path." Of course he lost wild man. but we shouldn't imagine he was a Schopenhauer. Now the remarkable thing is that the notes of Western music are a manifestation of the first notes of this parallelogram of forces: C (GE) (DB) F (CA)." " is produced. These have different scales. and we may infer that it also came into being in this way. We shall then be able to take up more consciously where we left off. Other peoples besides those of the West have music much about it. 1933) n If we go on meeting.
We see how hard it obviously is to grasp ideas in music. Take his well-known aphorism about that washes against the shores of thinking. how much I revere him but here he is music constantly making mistakes. As you listen to me now. and saw Bizet " " man. more valuable one. a single part a folk tune. so absurd that Karl Kraus should have gone wrong in this way! What's the reason? Some specific talent. you must be following some logical train of thought. Obviously he was forced to find a substitute. It's always the same: mediocrities are over-valued and great men are rejected. he identified the Valkyrie with Nora and he couldn't stand Ibsen. I know how to tell a banal idea from a loftier. I recognise whether I am faced by a vulgar. The Catholicism of Parsifal was the official reason for the you see. hidden there was a wild and woolly man called it was long ago I remember it. There was even something of his printed " Die Fackel. If I sing something simple.wouldn't have as the split it. a thought. a blue sky or something of the sort. without a deeper dimension. Otherwise these exceptional minds wouldn't have gone wrong! But it was precisely the ideas that they didn't understand. something extra-musical. But someone of that kind doesn't follow notes at all. this sort of nadir is unthinkable. And there was a further confusion of ideas. Herwarth Walden. They didn't even get anywhere near them! Again. I needn't say what Karl Kraus means to me. So how do people listen to music? How do the broad masses listen to it? " moods " of some Apparently they have to be able to cling to pictures and kind. Strindberg! Have you read what he says about Wagner? That all good passages are stolen from Mendelssohn. For a man like Nietzsche surely weighed every word he said and wrote. made propaganda for Kokoschka. then they are out of their depth." The most miserably amateurish stuff. banal idea that has nothing to do with whether it's a well-known idea . seems to be necessary if one is to grasp a musical idea. a musical idea there? For anyone who thinks musically. at least and that's where I hope to help you a little there's no doubt what's going on there. That whole sentence from Karl Kraus about " the shores of thinking " is so typical! Surely it's meant dis** a vague mess of feeling " paragingly. and also composed. or the " Tristan that the musical idea takes up only shepherd's melody from a little space. which one must have got from somewhere. doesn't everyone realise that there's M a theme. not a trace of music in or musical ideas! Yet Karl Kraus printed it! in If It's " we compare notes with the visual arts. his But most recently Karl Kraus! This is an interesting problem." This shows clearly that he is quite incapable of imagining that music can have an idea." a melody. Since he was talking about music he should not have let anything extra-musical make him break with Wagner. Is what Bach and Beethoven wrote "so 14 . If they can't imagine a green field. who was a great admirer of Karl Kraus.
related notes form the notes 15 . Then This human I recall nature." Concretely. in the particular form of I art. "What ing. rightly that corresponds to the theory The laws of musical so values? " moral gain. Yes nobody wanted to be. Where something special has been expressed. My regarded as. one of his superiors asked him. then one's bound to find one's relationship to such minds entirely changed! One stops being able to imagine that a work can exist or alternatively needn't it had to exist. believe in?" You'll know what I mean by these " directions. And why is it important to take this into account? Look at the music of our time! Confusion seems to be spreading. the only question is whether the present time is yet ripe for them. Ever subtler differentiations can be imagined. in surprise. laid down by the nature of sound. So. not with all these dissonances you get nowadays!" For we find an ever growing appropriation of nature's gifts! The overtone series must be time. practically speaking. So it's from the " parallelogram of forces " of the three adjoining." But that comes later! Or." I repeat: the diatonic scale wasn't invented. "Would you perhaps be the composer. direction should we go in. notes are natural law as related to the sense of hearing. This is the one path : the way in which what lay to hand was first of all drawn upon. So nothing could be more wrong than the view that keeps " cropping up even today. by any " chance?" to which Schoenberg replied. as it always has: They ought to compose as they used to. as you have heard. But the path is wholly valid. a saying of Schoenberg's when he was called up. unprecedented things are happen" So there is talk of directions. complex a complex of fundamental and overtones. there has been a gradual process in which music has gone on to exploit each successive stage of this complex material. infinite. rather. Art is a product of nature in general." The second gets quoted Goethe to you. " That's the moral gain.round and about ideas? What of language which Karl Kraus form-building! is it. to give you a better idea of my approach to is why: so that you should recognise the rules of order in art just as in nature. centuries always had to pass until people caught up with it. Last we looked at the material of music and saw this rule of order. perspectives this opens! It's a process entirely free from arbitrariness. So we should be clear that what is attacked today is just as much a gift of nature as what was practised earlier. then what lay farther off. and its corollary was very simple and clear: the overtones given. a note is." When one thing Karl Kraus starts from is the an inkling of the laws. and from this point of view there's nothing against attempts at quarter-tone music and the like. so I had What to volunteer for it. Now. it was discovered. constant concern is to get you to think in a particular way and to look at things in this way.
which goes on developing further. could be felt as a spice. Schoenberg was the first to put into words: these simple complexes of notes are called consonances. the disappearance of which so provokes people. only one of degree. Naturally that's nonsense. of the first primitive relationships that are given as part of the structure of a note. closest relationship just the most important overtones. Yet another thing which. can not have been otherwise.of the scale. obviously rules of order soon appeared. But the way one looks at it is most important. What necessity? To say something. So we this. The triad. In this sense music is a language. which starts with accusations that he uses dissonances too much. As regards the presentation of musical ideas. shall try to How have musical ideas put our finger on the laws that must be at the bottom of been presented in the material given by nature? 16 . not thought up that form the diatonic But what about the notes that He between? Here a new epoch begins. express someIt thing. plus the second one tion of these overtones. Why all the work. that's the battle music has waged since time immemorial. by means of notes. scale. However. and which has played such a role in music up to now: what. because the entire realm of possible sounds is contained within the notes that nature provides and that's how things have happemed. then. if one could say it in words? We find an analogy in painting: the painter has appropriated colour in the same way. in the last quarter of a century the step forward has been a really vehement one. another step up the scale. but it was soon found that the more distant overtone relationships. those that are in the something natural. So for what purpose have men always used " what nature What stimulated them to make use of those series of notes? provides?" : There must have been a need. that couldn't be said in any other way. We do not know what will be the end of the battle against Schoenberg. Such rules of order have existed since music has existed and since musical ideas have been presented. But we must understand that consonance and dissonance are not essentially different that there is no Dissonance is only essential difference between them. But anyone who assumes that there's an essential difference between consonance and dissonance is wrong. so far as I know. It tries to tell people something. is this triad? The first overtone that's to say a reconstrucdifferent from the fundamental. which were considered as dissonances. But something else is just as impprtant we have already spoken before about musical ideas. some underlying necessity. So it's and we shall deal with it later. and an imitation of nature. and of a magnitude never before known in the history of music one need have no doubts about saying that. That's why it sounds so agreeable to our ear and was used at an early stage. to express an idea that can't be expressed in any way but sound. It's an accusation levelled at everyone who has dared to take a step forward. for what we call music to have arisen.
a start." So we extend the meaning. flat surface also makes comprehension impossible. Ideas. Things alter if something at least is given. then you have grasped it. you comprehend it. (27th February. '* what does the actual word comprehensibility of something. So a smooth. whose outlines I can make out. 1933) m Today my mind is not entirely on the subject because of a case of illness. the ever-extending conquest of the material provided by nature. been striven for. Proof: the triad. step further. Everything that has happened. have a special word for this: comprehensibility. something comprehensible is something of which I can get a complete view. But what constitutes a start? Here we come to differentiation. We want to talk about the development of the new music. the natural similarity between simple and complex combinations of sound. With this object to try to express an idea universally valid laws are assumed. If I want to communicate something. with the underlying thought that among the various trends which have come to exist there must be one that will seem to us to fulfil what the masters of musical composition have aimed at and striven for since man has been thinking musically. if you take an object in your express? " " hand. go You want to " get hold " a " 17 . What I say must be clear. the way that as it developed the first thing picked on was what lay near to hand. This exploitation of this given material. I mustn't talk vaguely around the point under discussion. which is a reconstruction of the most immediate overtones. clearly as possible. I explained to you the primitive things. What was decisive for these musical events? We discussed one point last time. aims at fulfilling these laws. How Presentation of a musical idea: what is one to understand by that? The presentation of an idea by means of notes. then I immediately find it necessary to make myself But how do I make myself intelligible? By expressing myself as intelligible. What did one say? have ideas been formulated according to musical laws? Here we shall follow this development in its broad outlines. For us the crucial thing is not points of view but facts. Something is expressed in notes so there is an analogy with language. What must happen for a musical idea to be comprehensible? Look: everything that has happened in the various We epochs serves Let's this sole aim. how the diatonic scale was acquired. Clearly this must be the supreme law.We hope this will teach new music can really point us to distinguish as clearly as possible what in the the way. But the second point was followed by the ever more thorough is this: one had something to say. The highest principle in all presentation of an idea is the law of comprehensibility. But if it's a house we " cannot take it in our hand and comprehend it.
That brings us to the point in history where we must start observing. and always has been. in primitive folk songs. that there are similar relationships ensuring unity. And the idea of trying to compose anything extra to " clarify " this This is something unique in shepherd's tune would be incomprehensible! later music." divisions for? One could say that ever since music has been written most great artists have make this unity ever clearer. so it must also happen in music. in painting. but at least it gives me an initial approach to differentiation. whence we are to follow the path." Let us sum up what we have broadly discussed." gible. for example. then. Naturally this example." at a time when colossal things had already happened in shows that it was still possible to express so much with a single line even music. and that these things were aimed at by us. is flat surface. for all time. and if you bring in something else as an illustration you mustn't wander off into endless irrelevancies. striven to comin the much-disputed method of composition that Schoenberg calls shall treat this position with twelve notes related only to each other. and unity. But for me the most important thing is to " We show how this path has unrolled. is entirely when we find other things that can be grasped. the most important thing. I can only sense. but I know above all that it's so in language. you mustn't forget the main point. otherwise you are unintelli" Here we have an element that plays a special role: hanging-together. this principle In any case it's possible and conceivable for a musical idea to be presented by only one part. and I believe that in our time we have discovered a further degree of unity. comprehensibility is also guaranteed. to make yourself intelligible. hanging-together. to distinguish between what is principal and what is subsidiary. What are differentiation? Broadly speaking. which is fundamental in our discussions. That's so not only in music but everywhere. the very primitive. Things change What. In Western music monodic song was the rule in Gregorian chant. In the pictorial arts. that's to say the distinction between main " and subsidiary points. And all the rest is dilettantism. Schoenberg even unity. It is clear that where relatedness and unity are omnipresent. for is smooth wall here divided by pillars. meant to write a book "About unity in music. Composition with twelve notes has achieved a degree of complete unity that was not even approximately there before. and we see that. So the whole thing must hang together. differentiation. If you want to make something clear to someone. Unity serving comprehensibility of ideas! In the various epochs of music has been respected in varying ways. not prove. We should and must talk about the space a musical idea can occupy. nothing else. 18 . it was customary at the outset.We mentioned a smooth. And the shepherd's " tune from Tristan. will be necessary to make an idea comprehensible. the introduction of divisions! To keep things apart. But today I want only to deal with one more point." method at the end of these lectures. This is necessary. then. Everything that has happened aims at this.
But what idea of art If I've been at pains to make clear to do Hitler. 1933) IV Ever fewer people no. What's going on in Germany at the moment amounts to the destruction of spiritual life! Let's look at our own It's interesting that the alterations as a result of the Nazis affect territory! almost exclusively musicians. they tried to make more room." I mean the group that doesn't aim at external success. Imagine what will be destroyed. After that. that several parts have to be called upon to present a musical idea? To work it out clearly yet again: at a very early stage it was found necessary to bring another dimension into play. there was a rapid flowering of polyphony. wiped out. That can't be chance! It wasn't a matter of arbitrarily adding another part. The idea found it necessary to be presented by several parts. that one part is not enough. for instance? level. The idea is distributed in space. they showed some and they were given their jobs because they were allowed to reach But what will happen next? To Schoenberg. and later on ideas were born that could not be presented in this way. and one can imagine what's still to come. and that's the nature of polyphonic presentation of a musical idea. We shall deal with the principles that governed the gradual exploitation of the tonal field the natural resources of sound. I should like to give you proofs of it. When several parts sound at once the result is a dimension of depth. The first person who had this idea perhaps he passed sleepless nights he knew: it must be so! Why? It wasn't produced like a child's toy. Goering. by this hate of culture! a certain And But let's Goebbels have? leave politics out of it!. What " will come of our struggle? (When I say our. it isn't only in one part one part can't express the idea any longer. Berg and myself (Krenek too). At the beginning ideas could be comprehended by one part. What does it mean. That isn't chance. that's part of the lecture! can nowadays manage the seriousness and interest demanded by art. only the union of parts can completely express the idea. later on it will be impos" cultural sible to appoint anyone capable even if he isn't a Jew! Nowadays " Bolshevism is the name given to everything that's going on around Schoenberg. so that more room had to be found and the single part had to be joined by other parts. absolute necessity compelled a creative mind: he couldn't manage without. though at present it's linked with anti-semitism.) And even if many people who were obliged to believe in it distinction didn't really adhere to the ideology I'm talking about.But let's say it straight away it was soon found necessary not to limit the presentation of a musical idea to one part. (7th March. you the things that 19 . the idea isn't expressed by one part alone.
At the very least one's thrown to the wolves. certbelieved ainly. who is the climax and unites both methods of presentation. and the " " concept of accompaniment appears. Now we are not far off a state when you land in prison simply because you're a serious artist Or rather. but I don't know what Hitler understands by pened already I know that for those people what we mean by it is a crime. I ! of whether anyone's there or not it was done in an so difficult to shake off politics. but it was that things would still work out somehow. similar things are to be seen in Jewish ritual. it's hap" new music". and now pay (In passing. that attention! musical ideas had to be presented so that they took in not only the horizontal but also the depth of polyphony. and saw that it's possible to sum up the whole idea in a single part. which is connected with more primitive elements dance forms and the like. dance form. S. so that toward the end of the 17th century it was already at an end. develops. the idea must be disposed of by the one part. It's a great flowering of polyphony. Bach. The moment is not far off when one will be locked up for writing such things. which goes back to Bach and see another we 20 . But during the years when polyphony was still developing ever more richly. Gregorian chant. as it were development of the ideas and principles we arrived unity. but I find it important to take the matter farther in this light. And I added as an example that there was a whole artistic species where musical ideas were presented in only this way. What is it? What are we to under" stand by accompaniment?" I don't know whether all this has so far been dealt with from this point of view. but certain tendencies of the musical functions have to be made clearer. Surely it's remarkable for one person to sing and another to "add something!" So there's a hierarchy: main point and subsidiary point something quite different from true polyphony. We shall consider later how far it exploited the tonal field.) Starting from the view that an idea can be presented polyphonically. the more popular formal type. how history at: comprehensibility shows the and discussed the question of how much space can be assigned to the presentation of musical ideas. How it's growing and changing! A few years ago. we saw changes happening hi artistic production. What do we see growing up now? (It goes as far as J. in an independent melody.) But it was felt that this space had to be expanded. It arose along with the rites of the Catholic We church.must happen irrespective entirely opposite spirit. method of presentation emerging. spiritual Now let's see at the last moment. It's matter of life and death. Here again the idea is not exhausted by one melodic line. hour? If not. and what methods it used. In this period. because they're a But that makes it all the more urgent a duty to save life Will they still come to their senses at the eleventh faces an abyss. So how did music evolve in the course of centuries? The Netherland style developed very quickly. With monody. what can be saved. made an economic sacrifice.
The final result of these tendencies is the music of our time. But at this point interesting things happened: " " the accompaniment's supplement to the single-line main part became steadily more important. and we can see that the two methods have inter-penetrated to an ever-increasing degree. Let's look back! (Schoenberg's last lecture is the stimulus here). since polyphony was an accepted thing. methods of presentation have alternated. unaccompanied: in fact everything is there that had to be expressed. want to be quite clear that in classical music there is again an urge to express the idea in a single line. But now it's interesting to see how things break up. a period that limited itself to thinking of fine melodies for the voice. and to providing a supplement for the melody. how there was a return to the limits of a more primitive method after the extraordinary achievements of polyphony. and its sequel is that today we have arrived at a polyphonic method of presentation. We set out from the seven-note scale. But the polyphonic epoch was superseded by another which.Handel (though one shouldn't mention the two in one breath!). It's the period that saw an extraordinary widening of the tonal field through a new emphasis on harmony. This is the period when the homophonic style begins. How can we understand the work of contemporary masters from this point of view? It's produced by time further back. This method of presentation reached its climax in the Viennese classical school. of the material! So. but without exploiting true polyphony. There was again the urge to cram the musical idea into one single line. once again. when opera developed. for 21 . to achieve ever firmer and closer unifying links between the principal melody and the accompaniment. Now we are further on in time. In the classics there was an urge to compress the entire idea into one line. in the accompaniment. This happened quite imperceptibly. quite gradual and without any important divisions. conveyed by the one part. And it's interesting that the function of the accompaniment strikes out along a new path. One can imagine singing a tune by Mozart. and to add constant supplements in the accompaniment. and now the remarkable thing is that in Bach's time the conquest of the twelve-note scale and at the same time that of harmony were achieved. there was a transformation. at first in a primitive way. since presentation of musical ideas developed either through a single line or through several. the period of Monteverdi. the allimportant factors must have been the ones aiming at presentation in which one part is the most important. stemming from the urge to discover ever more unity in the accompaniment to the main idea that is. ever-increasing conquest We I should like to put it in another way: to take the broadest view. reduced to bare essentials. which in its turn is developed. we cannot create works by the methods of a we have passed through the evolution of harmony. limited itself to a return to single-line melody with " an accompaniment " of course. or one of Beethoven's themes.
What's the easiest way to ensure comprehensibility? Repetition. in order to make oneself understood. the most artful things developed. Alleluia with verse in melismatic style (8th mode) We How does that strike you? I said last time that the first principle is comprehensibility! How is it expressed here? It's astonishing. the basis of our twelve-note composition is that a certain sequence of the twelve notes constantly returns: the principle of repetition! Finally. something this simple more general. We've arrived at a period of polyphonic presentation. All formal construction is built up on it. exactly as in Beethoven's symphonies. So let's go back to earlier epochs! First I shall show you something from the monodic period. We must be clear as to how all me from the first. Let's learn this lesson from phenomenon. three sections! The second is different the third is like the first find this in a melody from the 12th century! Already it formulates the whole structure of major symphonic forms. structure. as often as possible. with all the other things that have resulted from the conquest of the tonal field. in which the first section is repeated. from the time of Now we Gregorian chant. more often. naturally. how must look at some examples and see how things have happened. and the parts also contain repetitions. these principles have been realised. play the piece again you see. 1933) 22 . all musical forms are based on Let this principle. We primarily a symmetrical A-B-A shape. and if you like we can jump to our own times. this comes about. this idea (14th March. the way all the principles already show up here! What strikes us first? The repetition! find it almost childish. what it expresses: it is such as one knows from one's own body. to create a shape that's as easy as possible to grasp. and our technique of composition has come to have very much in common with the methods of presentation used by the Netherlander in the 16th century but.the inter-penetration of these two methods of presentation. The task was So we have a three-part from our example: of saying something twice.
the so-called leading-note. We see how the tonal field gradually Do you know how this scale was used.Last time we dealt with the various epochs during which the role of musical space has varied fundamentally. showed a constant alternation between and more modest demands on musical space. C on B Hypophrygian. The special thing about the Ionian mode our major was that it had a semitone. what did this period do for the principle of comprehensibility? We comprehensibility must look at all this from two standpoints. This is the framework everything else that helps the principle of comprehensibility is arranged round greater it. on the other that of the conquest of the tonal field. history also The monody of Gregorian chant was followed by a period of polyphony. The seven-note scale starting on C is Ionian. apparent not only in the Netherlander but also in Palestrina and the German masters of the time. so they always contain this scale. in what forms and shapes? I mean the church modes. They started on particular notes of the scale. What are the church modes? How did we pass from the modes to the diatonic scale? The church modes are built on each step of the seven-note scale. on F Lydian. The second point we dealt with was the combination of presentation methods in particular historical periods. the one on Dorian. before the was soon found that an ending with leading-note and tonic is especially recurrence of the tonic C. on D G A Aeolian. on the one hand. A text. It 23 . Now. We saw that there were epochs when one type of musical presentation was expressed differently and to a greater degree than in others. on Mixolydian. That was the time when the diatonic scale developed out of the church modes. on E Phrygian. On the other hand. that of and unity. End of a Rondeau by Jehannot de 1'Escurel three-part song on a French covers the whole diatonic scale.
and that's why the semitone also came to be introduced before the recurrence of the tonic in the other modes. f From a three-part song motet by Guillaume Dufay We see third is that it ends on one note.effective. End of a 24 five-part tenor motet by Senfl . which already ends with the third. Another piece ends on the open fifth. So you see again that this is all entirely in accordance with nature. So the decline of the modes happened through the addition of leading-notes foreign to the mode. The missing there was neither major nor minor. In our example we still have the seven notes. called accidentals. nobody trusted himself to use it Now an example from the 16th century. Bach began. By then the additions had already gone so far that all twelve notes of the chromatic scale could be used. But this meant that the modes condensed into two groups major and minor and that was the end of them. whose essential difference lies in the third. At the moment when only major and minor were left the period of J* S. namely an extra note. but at the moment when the authentic seventh was replaced by the " ** . something was there that led sharpened one hence the name accidental to chromaticism. by Ludwig Senfl. there could be no major or minor the third was felt to be a dissonance.
as I'd like to go through with you the forms produced by the urge toward the clearest possible presentation of ideas! It's the next epoch that gives us an " how can the principle of repetition be ask ourselves. but What can we conclude altering the direction of the intervals (inversion). fourth and sixth parts sing the same thing. The fact that they sing the same thing at different moments makes unusual cleverness unity. but beginning on a different degree of the scale. The climax is surely found in Beethoven.This contains the essential points in the exploitation of the diatonic scale. The repetition of motives and the ways in which it was managed these we find in the next epoch. That occurs as one line unfolds. slightly altered conditions. Initial imitation! Resourcefulness soon went further. is it possible for several parts to sing the same thing one after the other? That's the essence of canon. in the sense that the various simultaneous parts are not unrelated. find traces even in early when the idea is carried by a single line?" applied polyphonic music. Here we see the beginnings of polyphony based on this principle of repetition. However. But then the following also happened the series of notes was repeated. like Now We We A music example must be missing here. not only rhythms are repeated. from Bach till the development of the classical forms. insight into this. and a let's look at this epoch from the other point of view! What do we find as regards the presentation of ideas? In dealing with Gregorian chant I've already pointed out that the principle of repetition is enormously important in Now enhancing comprehensibility. sequences a certain rhythmic succession is repeated. in the interests of comprehensibility. precisely in necessary. is But the reason The successive entries order to create a relationship. How is it in this example?* Something can be repeated in the same way or a similar one. hesitant attempt to end with the third which means an approximation to major and minor. something can be the same but under when the line is turned backwards (cancrizan). At first it isn't an exact canon. since Webern refers to six parts whereas the Senfl passage is in five. How always the urge toward the greatest possible meant that the opening motive took on greater importance. but at the outset there was always the need for each part to enter as the preceding one had done. By "motives" we mean. but the whole course of the melody. the closest conceivable relationship between several parts. Earlier we said that unity was at first produced through inversion and Here we have the reversal but then we hadn't begun to discuss rhythm. 25 . Now we see how all that developed along these lines is based on this principle. a relationship is produced among them the third. But what happened here? The repetition of motives. primeval form of the motive. from this? What are we to make of it? We already see in this epoch that composers' every effort went to produce unity among the various parts.
This period form. less here than in Gregorian chant! easy to grasp. Why is it is this so simple? Because it's simple repetition. S. this way of shaping the melody and the layout of the notes. since there possibility of repetition it's been exploited in various ages to express as as possible to much accommodate a rich store of musical shapes. and a form J. But the period. Bach. we recognise one? Because it's repeated! But how do We see something similar in tion. Sarabande 26 . on the other hand. as demonstrated here. 5th English Suite. provides one of the most important forms in which a musical idea can be presented. such as occurs above all in folk song. can be constantly folk song. If as a contrast I Gregorian chant. But soon the need was felt to shape things still more of thematic structure arose that's rather like this: artistically. Here we find period form. is only one of the forms in which an idea could be presented along these lines construction of melody and is in fact the more primitive one. and the most unprecedented ideas were later expressed through this form. to introduce order. But.Schoenberg. the smallest independent particle in a musical idea. everything much more amorphous. The urge to felt in produce order. everything is based on repeti" Kommt ein Vogerl play the quite banal melody " geflogen how much firmer the shape of everything is is There.
beneath it all is the urge to express oneself as comprehensibly as possible. this remarkable course of events that what we saw in polyphony. I've gone in a certain direction. (20th March. and now we find this process. Last time we looked a little at the Netherlands school it's a long way from there to the present! But you'll see that it all unrolls surprisingly smoothly. the development of forms in which presentation of musical ideas calls for a single line. The way this happened was that motives were developed.Unlike the period. We Last time I talked about the period and the eight-bar sentence. something new could and had to follow at once. immediately repeated. It can be seen that these forms have gone on providing 27 . shall talk about this next time. so instead of four bars' antecedent and four bars' consequent there are two bars immediately repeated and since there was immediate repetition. 1933) VI haven't so much time left and must see that we get to the end of the There are three lectures left. The period and the eight-bar sentence are at their purest in Bach. but there was a deeper problem involved. and I want to go on and show you how this presentation was perfected. in his predecessors we find only traces of them. especially in Beethoven). hut one of only two bars. matter. this isn't a four-bar structure (the normal form. In this connection we've talked about forms. the greatest possible unity. So we see that even in the fullest and purest musical structure we can find quite simple forms. But development is also a kind of repetition. and that a new polyphony is developing. the highest flowering of polyphony was reached with the Netherland school. Not even in Haydn and Mozart do we see these two forms as clearly as in Bach. and here I want to say only one more thing. Why did recognise clearly: what is expressed here? as they did? Now. Everything that came after Bach was already prepared for. that's to say the so-called Netherland technique that this tendency is again gradually taking possession of these these forms And now we must come about We things. But everything can be traced back to them. the same thing twice. the basis of all thematic structure in the classics and of everything further that has occurred in music down to our time. And these two forms are the basic element. It's a long development. and it's often hard to make out those basic elements. and later we see all this polyphony come to an end and be replaced by something quite different.
Brahms and Mahler is also looked at two examples from the great days based on these forms. for about a quarter of a century. major Now we must look at the further So how did major and minor come to be superseded? As in the dissolution of the church modes. and this scale bebasis of structures that led beyond the church modes. "mode"=*"Tonart ". ambiguous chords appeared. Here indeed the remarkable thing is that the need for a cadence was what led to the preference for these two modes.B. until a time had been reached when these wandering chords were the ones most used.the basis for all construction of themes. and the world of our major and minor genders* emerged. gender ** normally also be translated as mode ". L. a new music has existed that has given up this " " double gender in its progress toward a single scale the chromatic scale. the days of the style simultaneously see the of the development from diatonicism to chromaticism twelve notes. were predominant down to our time. as well as being used in this way at the end. conquest of the tonal field! The two tonal and minor. it will throw light on the music We of our day. It was then transplanted to the other scales. The cases are quite analogous! As part and parcel of this " " cadence came urge to define the key exactly. So accidentals spelt the end for the world of the church modes. and the moment came when the keynote could be given up altogether. the need for the leading-note that was missing in the other modes. so that they became identical with the two enduring ones. marked by the rise of the Italian opera. the very end of a piece the to contain a number of chords that by their nature couldn't be clearly related to one single key. Major and minor finally became established during this period. beginning to the conquest of the recapitulate: first men conquer the seven-note scale. " * In the original. So when did all this come about? Let's first discuss when and where the major-minor genders became established. that's to say. which would 28 . Wandering. It was the time after the Netherland school. the destructive elements came of the urge to find a particular type of ending. too ! saw how the conquest of the tonal polyphonic field gradually came about . the epoch I've mentioned several times already. because everything that happened after the high classical period particularly in Schumann. "="Geschlecht". genders. of polyphony and saw let's say this quite clearly. And now we see how gradually two of these scales come ever more to the fore and push the To came the others aside: the two whose order is that of present-day major and minor. but now. and they were also introduced in the course of the piece. So the course of the piece became steadily more ambiguous.
dominants were produced on " inter-dominants. von Gpfffraf SA /6* ge- r 'rJCirr >r 'i r r . S. Through this cadential history repeated itself in major-minor tonality. Here already is a piece wholly based on what we call chromaticism. We must sum up again. r * - ii r r r ge- AW* .S /- -/- I ^^ J. as one tried to end in an ever more complex way. mediant and subdominant and between the leading-note and tonic. on progression by semiThe semitone was indeed also there in diatonic music. Notes were introduced that didn't belong." and this has already each degree of the scale so-called happened in the chorale arrangements. and it was function just there that the dissolution had begun. eta* etas hoi. and this led to the situation where major and minor were done for. between the tones. more interesting shape to major and minor. Let's look at the other point. at the cadence. the ? I've already mentioned presentation of ideas! What happened in this epoch 29 . 1 u r r r cfes ^/o/ zetcfi- /rtf/ etas -1 ' ^^ eJ 9*/ AflCWT 1 I u > f J Hal- 4I/7. That's how it happened again hi our time. once again accidentals. to give an ever richer. only note how it became possible for all the things of today to happen. of the world in which the twelve notes hold sway. From there one ranged ever farther abroad. chorale. Bach. the conquest of chromaticism came about in the same way as that of major and minor. or rather it's already there. " Christ lag in Todesbanden " make of this? What has happened? What plays the main mustn't look at it aesthetically. once again at the end of the What are we to role here? We piece. It is the emergence.. until the new accidentals came to predominate. we drew on chords that were steadily farther removed.
that immediately before Bach polyphony broke off and the development of a melodic type of music ensued. Already this is the form of the eight-bar sentence of the kind found most clearly in Beethoven. that can be described as an is eight-bar sentence. found it's remarkable to observe I've deliberately described the basic already.) mental in further merely to hint at what happens during this development the harpsichord. Bach's melodies and those of his time we find only the seeds of the development that reached its climax in Beethoven. du liebes Herz " Here already we have the essence of the eight-bar sentence in blueprint. Bach. the emergence of instrumental music. Development of an idea can be seen quite clearly. forms not to be In fact in What is a melody of this kind like in Bach ? J. Now. S. The most important point for us is that the forms fundadevelopments grew up in association with these influences. So here again Bach is involved at a vital stage in the development of music. and dance forms also belong here. it's the form most favoured by post-classical music. a figure repeated. (These dance forms become an important influence through their connection with instrumental music. aria " Blute nur. not so clearly even hi Mozart and Haydn. you need only grasp what was aimed at in its use). associated with the opera. in Bach we find not only the organ but the lute. (It isn't so important for you really to understand this form completely. Matthew-Passion. In any case it's been used more than the period. then it's repeated again. with its instrumental accompaniment. I mention this because it introduced elements into music that came from a different sphere and gained a great influence on all the further developments. in contrast to strictly musical thinking: folk music. the period and the eight-bar sentence that a pure culture is until Beethoven. for example. then there are two variations of it. etc. Here something played a role that mustn't be overlooked. I want suite form. Now I want to show you a passage from a Beethoven sonata. 30 .
Verklarte Nacht. Curves became longer. v. 2nd subject in E major Here we find the periodic version again*. the first six bars return (in varied form) at the end of the example. 1. 31 . ever more broadly spun * i. whereas later one became freer and left out certain intermediate stages.B. like the links of a chain. But what else plays a part? The fact that repetitions were carried out with ever-increasing freedom one proceeded by variation. 2 No. out. but the forms have been handled ever more freely." Things were more immediately and abruptly juxtaposed. 1st movement Here again we see a figure that's repeated and developed. since the development brought about by means of one motive led ever further afield. ftwas t-uftigcf Arnold Schoenberg. so I can jump to something else without carrying on the development any further.. Beethoven. What is this " freer treatment?" In one case the repetitions are literal and without gaps.e. L. thinking -metaphorically "It's happened once already. Nothing new has been added. which of course makes them harder to understand. The same form is always at the bottom of it. 1st violin.L. Piano Sonata Op.
Then on again away with it! What came next? Development of melody." I mean this music. conquest of chromaticism that's only vocal music. natural law as related to the sense of hearing for comprehensibility trying to create ever increases comprehensibility. altered rhythm." Here the element of comprehensibility is important above all to introduce ever more unity! That's been the reason for this kind of composition. cancrizan. destruction of the church modes: on the other hand. major and Instrumental minor. Last time I emphasised 32 . the greatest flowering of polyphony. because I still want to talk about the new music itself! hope you already have a general picture. since everyone has the same thing to say. a new expressive form in association with the folk song. (27th March. which has existed for about twelve " years and which he himself has called composition with twelve notes related only to each other. Now we come straight most recent times. music crept into the picture here. shall see led to the last decade's how these elements have gone on developing and have new growth. First I to the to These lectures are intended to show the path that has led to this music. and make clear that it had to have this natural outcome. So we see ever greater conquests in the field provided by sound as Goethe " " and the urge would have said. with the result that in the late Netherland school a whole piece would be built out of a sequence of notes with its inversion. just because unity Now we far. the very style. in headlines: diatonic scale. in relation Let's again I sum But to form. or is consciously opposed to it and thus uses a style we don't have to examine further. playing on instruments became an art. and here I want to say expressly what new music I want to discuss: the music that has come about because of Schoenberg and the technique of composition he discovered. more unity. for everything else is at best somewhere near this technique. since it doesn't get beyond what was discovered by post-classical music. 1933) vn Today let's recognised as most important tion of ideas! examine the new music with an eye to the two factors we've the conquest of the tonal field and the presenta- want to talk about the presentation of ideas. Beethoven. And the conquest of the tonal field? After the classics the break-up of tonality. and only manages to do it badly. one to another. through ever-increasing unity. composition with twelve notes related only It's the final product of the two elements we've observed so People are wrong to regard it as merely a "substitute for tonality. The greatest strides have been made by the very music. More unity is impossible. that Schoenberg introduced and that his pupils have continued.up. So once again. etc.
composers all began striving to create forms that made it possible to express their urge for clarity. and a Schoenberg theme is also based on those forms. which arose at that time and became the most subtly worked and richest movement of the cycle. too. is based on * Ger. Beethoven used it particularly in his Adagios.* which turned into the rondo. I remarked recently that instrumental music arose with the homophonic style of the Italian opera. at the beginning of the seventeenth century. Brahms. developments since Beethoven the eight-bar sentence has been used more. then. the true sonata movement. the period and eight-bar sentence. etc. Certainly a Mahler symphony is put together differently from one by Beethoven. the presentation of ideas. the Air. from Bach's predecessors to Beethoven. 33 . Later. " Kehraus ". it isn't easy to relate pieces to those formal types. The modern symphony. Bruckner. forms later manifest in the symphony. Mendelssohn. but in essence it's the same. Gigue. Most of these forms were later cast aside and there remained only the Scherzo (which Haydn still often called a Minuet). insofar as it uses self-contained numbers. all makes use of these forms. but they are there all the same. and indicated the forms that developed in connection with the popular type of dances and so on. and the light final movement. What happened then. that everything which has happened back to these forms. The period derives more from song. the kind created by Schoenberg. So the development lasted about two hundred years. but that the other factor was also present. that this new one thing I said the other day that after the First. It's a fact. they are the cycles that have developed in classical symphonies and chamber music. So in a sense it Now we find that hi derives from what's most generally comprehensible. Sarabande.. Here I'm thinking particularly of Suites by Bach's forerunners and Bach himself. This led to the development of those classical forms that found their purest expression in Beethoven. They are the forms in which principal subjects are cast. That's why it was important for me to concentrate my remarks on these two factors. or what is borne in mind in order to present ideas. after Beethoven. the presentation of ideas! Netherland polyphonic style had passed its climax. just as our music does. with Minuet. the music of our day. the Air. for instance in Brahms. that's to say Schubert. and nobody can disprove it. which is transformed into the Adagio second movement in Beethoven. headed by a prelude and with a Here we already see the main traits of the song-like movement. is the direct result of only the development of the tonal field and its ever-increasing exploitation. Mahler. We must be clear about what happened here: the aim was always presentation of an idea. the period and the eight-bar phrase. Beethoven concludes the development of these forms in which ideas were presented. and they are the forms that occur in opera. since then can be traced But one movement is still missing the first.music. Schumann.
one form of presentation was particularly developed the fugue. What. The last few years have tried rather to adhere very strictly to these forms. and nobody racks his brains to find anything new. desire for maximum unity. in the interests of comprehensibility. then. We've also referred to Bach in connection with the enrichment of the tonal For everything happens in Bach: the development of cyclic forms. is implied in the presentation of an idea? An upper part and its accompaniment. Nothing was to fall from heaven everything was to be related to what was already present in the main part. Forms were the result of this distribution of space. I should like to mention some of these." to derive things and partial forms very soon an attempt to remain was from the principal theme. And here the classical composers often arrived at forms " " in their canon and imitation. that recall those of the old Netherlander I should also point out. To put it schematically. the field. development of the motives contained in the shapes of the upper part especially expanded." a work that goes conquest of the tonal wholly into the abstract. which is constantly transformed: a thick book of musical ideas whose whole content arises from a single idea! It's What does derived all this mean? The idea. Everything is is from one basic from the one fugue-theme! Everything 34 . For the fugue derived from instrumental music. structure that arose absolutely from the urge to create a maximum of unity. I've spoken of the development as the part of the work specially created so that the theme *' could be treated. music lacking all the things usually shown by notation no sign whether it's for voices or instruments. with it all. rather late. We have already frequently mentioned the effort to achieve an ever tighter unity. Classical composers* symphonic form also resorted to this.these forms. In fact there was " thematic. staggering polyphonic thought! Horizontally and vertically. how does this happen? By repeating the theme in by introducing something that is the theme unfolding not only horizontally but also vertically that's to say a reappearance of polyphonic thinking. and in his own works. and. so it's very remarkable that what we know as fugue didn't in fact exist at the time of the Netherlander. everything is derived from the theme. quite aside Here a polyphonic form of musical thought developed from vocal music. that in Bach's time. But in fact that has only just become possible again. field. This is a various combinations. How has this urge made itself felt since the tune of the classical composers? Without theoretical ballast we could put it like this: at an early stage composers began to exploit and extend to the rest of the musical space the shapes present in the upper part. And here we must return to something earlier! " It's important that Bach's last work was the Art of Fugue." Now. no performing indications. almost an abstractionor I prefer to say the highest reality \ All these fugues are based on one single theme.
44
thematic."
section.
ment
And now we find this creeping This now became the arena,
"
"
into later forms, in the developas the fugue was earlier. The
thematically gradually shows itself in the accompaniment, too; an alteration, an extension of the original primitive forms has begun. So we see that this -our type of thinking has been the ideal for composers of
desire to
work
(Wagner's leitmotives are perhaps another matter. For example, the Siegfried motive crops up many times because the drama calls for it, there is unity, but only of a dramatic kind, not musical, thematic. Naturally Wagner often also worked in a strictly thematic way; moreover he, of all composers, played a great part in creating musical unity linked to that of the drama).
all periods.
if
develop everything else from one principal idea! That's the strongest when everybody does the same, as with the Netherlanders, where the theme was introduced by each individual part, varied in every possible way, with different entries and in different registers. But in what form? That's " where art comes in! But the watchword must always be Thematicism, thematicism!" thematicism,
unity
plays a special role the variation. Think of Beethoven's Diabelli great composers have chosen something quite banal as the basis of variations. Again and again we find the same desire to write music in which the maximum unity is guaranteed. Later, variation found its way into the cyclic form of the sonata, particularly in Beethoven's second movements, but above all in the finale of the Ninth Symphony, where everything can be traced back to the eight-bar period of the main theme. This melody had to be as simple and comprehensible as possible; on its first appearance it's even given out in unison, just as the Netherlanders started off by writing at the top the five notes from which everything was derived. Constant variations of one and the
variations.
To
One form
At times
same thing! Let's pursue that! Brahms and Reger took it up. Bach, too, had already written in this way. In fact Bach composed everything, concerned
himself with everything that gives food for thought!
But the accompaniment also grew into something else; composers were anxious to give particular significance to the complex that went together with the main idea, to give it more independence than a mere accompaniment. Here the main impetus was given by Gustav Mahler; this is usually overlooked. In this way accompanying forms became a series of counter-figures to the
main theme that's to say, polyphonic thinking! So the style Schoenberg and his school are seeking is a new inter-penetration of music's material in the horizontal and the vertical: polyphony, which has so far reached its climaxes in the Netherlanders and Bach, then later in the classical composers. There's this constant effort to derive as much as possible from one principal idea. It
has to be put like this, for we too are writing in classical forms, which haven't vanished. All the ingenious forms discovered by these composers also occur It's not a matter of reconquering or reawakening the in the new music. Netherlanders, but of re-filling their forms by way of the classical masters, of
linking these two things.
Naturally
it isn't
purely polyphonic thinking;
it's
both at once.
35
hold fast to this: we haven't advanced beyond the classical comWhat happened after them was only alteration, extension, forms. posers' abbreviation; but the forms remained, even in Schoenberg!
So
let's
but something has altered, all the same; the effort and thus to get back to polyphonic thinking, Brahms is particularly significant in this respect also, as I said, Gustav Mahler. " " What about Bruckner and the others?" I should say, Nobody If you ask, can do everything at once.'* In Bruckner it's a matter of conquering the He transferred to the symphony Wagner's expansions of the tonal field. For the rest he was certainly not such a pioneer; but Mahler certainly field. was. With him we reach modern times.
All that has remained
to produce ever tighter unity
Now
I'd like to take
a quick look
at the other point, the expansion
of the
tonal field!
Last time I quoted a chorale harmonisation by Bach, to show that something already existed in Bach that wasn't superseded by the later classical composers, nor even by Brahms: it's impossible to imagine anything more meaningful than these constructions of Bach's! Beethoven and Schubert never did it any better. On the contrary, perhaps they found other things more important. What's the point of these chorales? To provide models of musical thinking based on the two genders,* major and minor, which were fully developed by then! Here I have 371 four-part chorales by Bach there could just as well be 5,000! He never got tired of them. For practical purposes? No, for artistic purposes!
He wanted
clantyl
And yet it was this which sowed the fatal seeds in major and minor. As in " " the church modes the urge to create a cadence led to the semipleasanter tone, the leading-note, and everything else was swept away, so it was here, too;
major and minor were torn apart, pitilessly the fatal seed was there! Why do I talk about this so much? Because for the last quarter of a century major and minor haven't existed any more! Only most people still don't know. It was
so pleasant to fly ever further into the remotest tonal regions, and then to slip back again into the warm nest, the original key! And suddenly one didn't come back a loose chord like that is so ambiguous! It was a fine feeling to draw in one's wings, but finally one no longer found it so necessary to return to the keynote. Up to Beethoven and Brahms nobody really got any further, but then a composer appeared who blew the whole thing apart Wagner. And then Bruckner and Hugo Wolf; and Richard Strauss also came and had his turn very ingenious! and many others; and that was the end of major and minor.
up, I'd say: just as the church modes disappeared and made way these two have also disappeared and made way for a single series, the chromatic scale. Relation to a keynote tonality has been lost. But this belonged in the other section on the presentation of ideas. The
Summing
for major
and minor, so
* or
"
modes ";
see p. 28.
L.B.
36
It relationship to a keynote gave those structures an essential foundation. helped to build their form, in a certain sense it ensured unity. This relationship to a keynote was the essence of tonality. As a result of all the events men-
tioned, this relationship first became less necessary and finally disappeared certain ambiguity on the part of a large number of chords completely. made it superfluous. And since sound is natural law as related to the sense of hearing, and things have happened that were not there in earlier centuries, and since relationships have dropped out without offending the ear, other rules
A
of order must have developed we can already say a variety of things about them. Harmonic complexes arose, of a kind that made the relationship to a keynote superfluous. This took place via Wagner and then Schoenberg, whose first works were still tonal. But in the harmony he developed, the relationship to a keynote became unnecessary, and this meant the end of something that has been the basis of musical thinking from the days of Bach to our time:
major and minor disappeared. Schoenberg expresses double gender has given rise to a higher race!
this in
an analogy:
(3rd April, 1933)
vm
Today we shall follow the final stage of the development, and first we shall revert to the point about the dissolution of major and minor the disappearance of key. Last time we already looked at some of this when we discussed the
I mentioned that even in Bach's chorale starting point of the dissolution. harmonisations tonality was dealt a severe blow. It's very difficult to make
the recent final events understandable; but it's important to talk about them because lately people have tried to make out that this state of affairs is a quite new invention, although it has existed for a quarter of a century. I don't want a polemic, but just now there's a lot of talk about this, in connection with political developments of course, and things are made to look as if it were all something foreign and repellent to the German soul, as if the whole thing had boiled up overnight; quite the contrary, it's been stewing for a long time, a quarter of a century already, it's something that's been going on ever so long, so that it's become impossible to put the clock back and how would one set about it, anyway? I don't know whether there was the same weeping and wailing over the church modes: anyway, just at the moment there's a frightful
hubbub about
tonality.
We must get this quite clear, so that you know whether to believe me or not! wanted to show that the process in this case is quite analogous with what happened before. Above all, I say it because recently in the Austrian Radio's weekly, that's to say before the widest possible public, a Mr. Rhialdini he'd
I
37
the new chords were themselves altered. C major doesn't contain F sharp. F-A flat-C. and finally all these chords were felt to be natural and agreeable. The augmented five-six chord belongs here. so if I use F sharp in major perhaps as part of the dominant C then I have broken out of the key. to the key. But I don't want to treat it as that. major and minor are also dissolved. Then it went still further the cadential points were what contained the seeds of destrucThe church modes disappeared in an analogous way. who are merely re-writing the old music. Ambiguous chords were produced. and others built out of superimposed thirds. For example. in let's C major the supertonic could be D or sharp. above all. and so we got to a stage where these new chords were almost the only ones used. The ear gradually became accustomed to these complex sounds. then with inter-dominants. first the ambiguous chords. music came to use notes foreign to the scale of the key concerned. Even the so-called " Tristan chord " occurred before Wagner. for example the diminished seventh. and there's no need to discuss the others. . and finally we came to a situation where the ear no longer found it indispensable to 38 . and by analogy tion. also plays a part here. so we could still rejoin the key. nobody has gone beyond our style. Later this happened faster. So then something different was brought into play. Now go further. over. which can be related to our keys. because of the use of these dissonant chords through everincreasing conquest of the tonal field and introduction of the more distant overtones there might be no consonances for whole stretches at a time. " " Dissolution of tonality: in connection with Bach's special type of harmonisation. rather to relate it to the keynote which is destroyed as a result. There was also the development of harmony. which plays a great role in Wagner but isn't really anything so terrible it happens in any minor key as a diatonic chord on the mediant. Suddenly every degree was there twice usage. dissonances. In popular it's a matter starting from C major of using the black keys. which at first only appeared cautiously in passing or prepared. and not with the significance and the kind of resolution it has in Wagner. it was part-writing that led to chords of that kind. but related to the tonic. it has no sharpened notes at all. then one already had the still D twelve notes. for example.be another of those German composers has written that at present people are squabbling over whether tonality should be given up. with the tendency to introduce other degrees with their dominants. such as the augmented triad. when every degree was doubled. How did this happen? The original consonances in the triads were developed into seventh-chords. He may be: we see it quite plain. But we still related them to the tonic. Then there came the fourth chords. then the chords were still further altered certain notes in them were sharpened or flattened. of the dominant The minor subdominant. we don't need to squabble! As I said last time. But ultimately. but only in passing. With these wandering chords one could get to every possible region. too. That is a modulation.
So there came to be music that had no key-signature. otherwise it won't be enough to give satisfaction.When is one keenest to return to the tonic? At the end. The ear was satisfied with this suspended " " one felt still in the air state. Suspended tonality. we felt the need to prevent one note being over-emphasised. bound up with the twelve notes. " The piece is in this or that key. that's hard to explain. Now 25 years ago a jubilee. the dominance of the of chromatic progressions. and where for long stretches " it was not clear what key was meant. no less! This moment all Arnold Schoenberg was the man responsible. The links with the past were most intense. But things of this land piled up more and more. only when one has started. But it was soon clear that hidden laws were there. It's just in Beethoven that we find this very strongly developed. to prevent any note's " " of being repeated. too. especially toward the end. on the basis of chromaticism. brought up a particularly tricky point. course. at the end: the whole thing. happened in about the year 1908. the exact opposite became a necessity. What does one make of it? How are we not to repeat? When is a repetition not disturbing? I said the composition would have to be over when all twelve notes had been there. however. Now there was a stage chromatic scale. since there was no tonic any more. That's to say. everything that has occurred. No effort is too great when it's a matter of shaping this ending so that it really strikes home. or by intervals connected with chromatic progression. the tonic is constantly reiterated. 39 . of Then one can say. or rather since matters had gone so far that the tonic was no longer necessary. is to be understood in this way or that. 1933 so in which we it's I can speak from personal experience took part. Now I must carry on the tale from my own experience. it used not only the white notes in C major but the black ones as well. What happens when I try to express a key strongly? The tonic must be rather over-emphasised so that listeners notice. the work would have to end when all twelve notes had occurred. taking advantage Of course composition can't go on without note-repetition. One can also take the view that even with us there is still a tonic present I certainly think so but over the course of the whole piece this didn't interest us any more. and one day it was possible to do without the relationship to the tonic. to put in a more popular way. You mustn't imagine it was a sudden moment. So no note must be repeated during a round of all twelve! But a hundred ** " rounds could happen at once! That's all right. not of the seven-note scale. the ear fouud it very satisfying when the course of the melody went from semitone to semitone. Now. in order to make it stand out enough." But there was still a tune when one returned at the last moment." It only emerged refer to a tonic. Is that all clear? this it's moment. For there was nothing consonant there any more. nothing was missing when one had ended the flow of the complex as a whole was sufficient and satisfying. The chromatic scale came to dominate more and more: twelve notes instead of seven.
one looked for a particular form of row to be binding for the course of the whole composition. but they happened theory but by listening. too. to derive everything from one thing. Not only from the fact that we've lost tonality. " " The round of the twelve notes That really expresses the law. only its manifestations are different. That's what we sensed. Nature expresses herself in the " man. and even then something else could be heard at the same time. to work thematically. stalk. 40 . and thematic technique works as before. One put the twelve notes in a special order. And here we come to the salient point pay attention! now you will understand how the style arose. from the point of view of unity." That's what Goethe says. And now let's switch back to the masters of the second Netherland school! Then a composer would build a melody out of the seven notes. For unity I referred to the sum up: Composers tried to create unity in the is completely ensured by the underlying series. on this basis. of accompaniment. that would also have to obey the same law. position with twelve notes related only one to another. And it's Goethe's idea that one could invent plants ad infinitum. accompaniment. comrelated to this scale. And now everything is derived from this chosen succession of twelve notes. There can even be a twelve-note such chords have been written then one could start again. nothing not through more! Some remarkable things were involved. Man has a series of vertebrae. since here. and surely the maximum unity is when everyone sings the same thing imaginable! Let's all the time the maximum unity growth of melody. and so to produce the tightest maximum unity. For example. relationships between things. to whose course the composition was tied. And that's also the significance of our blossom. without any of them being chord repeated. One didn't leave the order What's happened? to chance. His Plant Metamorphosis clearly shows the idea that everything must be just as in Nature. and that can be sensed " " in them. Nothing else at all! But why was it interesting to us that *' the same thing " was sung all the time? One tried to create unity. it was found disturbing if a note was repeated during a theme. But the great advantage is that I can treat thematic technique much more freely. It's always the same. Primeval bone primeval plant. And in Goethe's view the same holds good for the bones of the human body. but always The same happens in Schoenberg's discovery. but in a quite matter-of-fact way. All twelve notes in a particular order and they have to unfold time after time in that way! particular succession A A of twelve notes is constantly there. particular form And what is manifest in this view? That everything is the same.then the other notes of the row must follow it. each different from the others and yet similar. round of twelve notes. This is very akin to Goethe's conception of rules of order and the significance that's in all natural events. root.
of composition. And we needn't be afraid that things will manifest themselves with too little variety because the course of the series is fixed. and moreover in a particular order. the basic shape. " his Jacob's Ladder. Now We C We've reached the end! Ever more complete comprehension of the tonal and clearer presentation of ideas! I've followed it through the centuries and I've shown here the wholly natural outcome of the ages. " and we younger composers have been his disciples. father of the West). 1933) * Theodor Haecker. about 1921. one was obliged to return to the tonic." tied himself not to twelve notes but to seven. That's " composition with twelve notes related only to each other. To take one more bird's-eye-view of it all: if this is the outcome of a natural process of sound as natural law related to the sense of hearing! what do we see working through I want to end by quoting a saying by one of the most this development? wonderful thinkers of our time: in his book on Virgil. the analogy has still to be developed. work in field the service of the Almighty. that's to say composition with twelve notes related only to each other. Just as earlier composition was in major. Enough to choose from! Until now we've found these 48 forms sufficient. these 48 forms that are the same thing throughout. Now we base our invention on a scale that has not seven notes but twelve. it didn't all come about in a hurry. 24). when one wrote in C major. Vater des Abendlandes " (Virgil. one was tied to the nature of this scale. But finally Schoenberg Since that time he's expressed the law with absolute clarity. practised this technique of composition himself (with one small exception). 12x4 making 48 forms." What we establish is the law. style How do I arrive at this row?" Not arbitrarily. (A tie of this kind is very strict. 1931. one also felt " tied " to it. starting from the Netherlanders. so that greater blessings!" " a primal blessing shall come to bestow (10th April. perhaps so that as many intervals as possible were provided." Naturally all this had its preliminary stages. But then what can one do with these? on every degree of the scale. " Vergil. Earlier. Leipzig. otherwise the result was a mess. but according to certain secret laws. we write in these 48 forms.* Theodor Haecker " " labor improbus mentions his expression referring to agriculture. can give rise to variants we also use the twelve notes back to front that's cancrizan then inverted as if we were looking in a mirror and also in the cancrizan of the inversion. the ties are only partial. Now I'm asked. in a work he has still not finished and that nobody has seen. I've mostly come to it in associa" tion with what in productive people we call inspiration. 41 . But speaking from my own experience. the course of the twelve notes. just as one enters into marriage the choice is hard!) How does it come about? I can imagine doing it on purely constructive lines. Schoenberg. Even in ** " his Serenade (Op. so that one must consider very carefully and seriously. That can base them makes four forms.
It's the only one of the old achievements that has disappeared. What's is music in no definite key. so I had a brief correspondence with " The Schoenberg about what such a lecture should be called. to show how one thing leads to another. tonality has been one of the most important means of establishing unity." Schoenberg gets a lot of fun out of this. But I don't want to trust you with these secrets straight away and they really are secrets! Secret keys. what doors have been opened with this secret key? To be very general. above all. but not ideas that can be translated into concepts A 42 . He suggested I didn't invent the to talk in path to twelve-note composition. in short. title you've seen. ." We must know. For I don't know what the future has in store . Today I want to deal generally with these things. So what has in fact been achieved by this method of composition? What territory. even those who only want to sit and listen passively. What has been given up? The key has disappeared! Let's try to find unity! Until now. Now we shall try to probe deeper into this story. what it means: "twelve-note Have you ever looked at a work of that kind? It's my belief composition. it's a matter of creating a means we could discuss to express the greatest possible unity in music. So: what is music? Music is language. Unity.'* that ever since music has been written. and people have unconsciously had more or less of an idea of them. human being wants to express ideas in this language. it's important to talk about these things I mean things so general that everyone can understand them. " Turning now to music. . after all. So in music. What is this twelvenote composition?" And what preceded it? This music has been given the " dreadful name atonal music.THE PATH TO TWELVE-NOTE COMPOSITION This year I was It's Schoenberg's. the aim is to make as clear as possible the relationships between the parts of the unity. Mondsee on this subject. it's to some extent historical. Perhaps. everything else is still there. since meant "atonal" means "without notes. to be is the establishment of the utmost relatedness between all com- ponent parts. Unity is very general. surely the indispensable thing if meaning is to exist. all the great composers have instinctively had this before them as a goal." but that's meaningless. as in all other human utterance. There we have a word all day. Such keys have probably existed in all ages.
main key kept reappearing. To out this main key more definitely. All the things familiar to us from primitive life must also be used in works of art. in the recapitulation. thematic development can produce many relationships between things. it's the most abstract music known to us. major has been This stage was preceded by the church modes. tonality. finally remained. of which only the two keys. distinguished from minor. Comprehensibility is the highest law of all. of an " idea. There was a A main key crystallise in the exposition. since the seventeenth century. No! Beside that. and it was natural for the composer to be anxious to demonstrate this key very explicitly. 26. in the development. it was left and returned to. Schoenberg uses the wonderful word " " comprehensibility (it constantly occurs in Goethe!). piece had a keynote: it was maintained. P. like genders. Canonic. 43 . and that's where we must look for the further element in twelve-note composition. there are things that look forward to the most important point about twelve-note composition: a substitute for * Cf. It constantly reappeared. have to keep picking out these things because Something had to come and There are two paths that led unavoidably to twelve-note composition. man only exists insofar as he expresses himself. contrapuntal forms. of producing unity. by looking back at its predecessors. it wasn't merely the fact that tonality disappeared and one needed something new to cling to. which was selected. There must be means of ensuring it. It was the principal key. Men have looked for means to give a musical idea the most comprehensible shape possible. " The most splendid example of Art of Fugue " at the end of this is Johann Sebastian Bach. there were codas. Returning to tonality: it was an unprecedented means of shaping form. These two have produced something that's above gender. I want to say something. and obviously I try to express it so that others understand it. work contains a wealth of re- lationships of a wholly abstract kind. What did this unity consist of? Of the fact that a piece was written in a certain key. and this made it predominant. What is a musical idea? (whistled) " Kommt ein Vogerl geflogen "* That's a musical idea! Indeed. in which the I that's disappeared. Unity must be there. that's to say seven keys in a way. etc. Throughout several centuries one of these means was tonality. who wrote the This his life.musical ideas. Since Bach. I'm discussing something restore order. (Perhaps we are all on the way to writing as abstractly). our new system of twelve notes. Music does it in musical ideas. there was another very important thing! But for the moment I can't hope to say in one word what it is. Although there's still tonality here." but Schoenberg went through every dictionary to find a definition he never found one.
This means the main key is at times pushed to one side. At " first one did think. we had the '* We don't need these relationships any more. one increasingly used substitutes for them. that instead of chords of the sub-dominant. In fact I disturbed him with " on the way to something quite new. Where has one to go. whatever can it be?" (The first beginnings of this music are to be found " in the music of Jacob's Ladder. to tell him I had read in some newspaper where a few groceries were to be had. then?" So it came about " 44 . inhibitions of the most frightful kind had to be overcome. Berg and I wrote before 1908 belong to this stage of tonality. " Do I really have to come down again?") The substitutes became so predominant that the need to return to the main key disappeared. and he explained to me that he was " we want it. Naturally this was a fierce struggle. and this finally led to the break-up of the main key. this stage lasted. If This whole upheaval telling you here is really my life-story. tonality too." The time was simply ripe for the disappearance of tonality. dominant and tonic.What I'm started just during the century has already gone by. and what one day. where the main key often has some other key forced into it like a wedge. From 1908 to 1922 was the interregnum: 14 years. and I lived quite near I went to see him one fine morning. Schoenberg saw by pure intuition how to restore order. What is a cadence? The attempt to seal off a key against everything that could prejudice it. 11 appeared. At first one still landed in the home key at the end. And then at the cadence. But composers wanted to give the cadence an ever more individual shape. Those were the first "atonal" pieces. the first of Schoenberg's twelve-note works appeared in 1922. one wondered. but gradually one went so far that finally there was no find the first longer any feeling that it was necessary really to return to the main key. Here I am at home now I'm going out I look around me I can wander off as far as I like while I'm about it until I'm back home at last!" The fact that cadences were shaped ever more richly. " Is that possible.") I'm sure it how tonality suddenly vanished. All the works that Schoenberg. go into another tonality here and there." this. The matter became really relevant time when I was Schoenberg's pupil. then it was about 1908 when Schoenberg's piano pieces Op. Since then a quarter of a For goodness* He didn't tell me more at the time. the panic fear. our ear is satisfied without feeling. when I began to compose. (When one moved from the white to the black keys. nearly a decade and half. But already in the spring of 1917 Schoenberg lived in the Gloriettegasse at the time. though. It was possible to tonality. will be very useful to discuss the last stage of tonal music. We breach in sonata movements. to find historically started until finally. and then altered even those it led to the break-up of The substitutes got steadily more independent. and does one in fact have to return to the relationships implied by traditional harmony?" thinking over points like that. and I racked my brains sake.
the sixth above the minor subdominant (in C. Suppose I'd written an * ' " in the style of the Gurrelieder? opera works in the same thing. music has quite simply given up the formal principle of tonality. This was the point where even classical composers often wandered far from the home key and used resources that had a fatal effect on the key at the very place where it was felt Certain chords and particularly important to let the key emerge clearly. they were misunderstood too. Look at Schoenberg! Max Reger certainly developed. (15th January. Beethoven and Wagner were also important revolutionaries. the chord F-A flat-D flat." Why don't people Naturally it's nonsense to advance understand that? Our push forward had to be made. 1932) II what led to the disappearance of tonality. You're them out. You surely know that the whole system is built on the fact that one regards the different notes of the scale as degrees and can 45 . Let's take another look at still are The desire to set up material contradicting the chosen main key even in the " " harmonic sense one could say. radicalising effect. it was a push forward such as never was before.) This example is itself enough to show clearly the path that could lead to twelve-note composition. and this is highly revealing. " social objections. I've tried to make this stage really clear to you and to convince you that just as a ripe fruit falls from the tree. too. There people who base their composition on tonality. And never in the history of music has there been such resistance as there was to these things. he could reel off fifty style. for example. and. to limit the district known as tonic and then where one wanted to show up to drive in wedges finally led to the very place these contradictions in a special light the cadence. the Neapolitan sixth. something new. that wasn't in a key any more. listening to someone who went through all these things and fought All these experiences tumbled over one another. firmly and consciously. deriving from this. the fiat second of C major. harmonic relationships had a radical. because they brought about enormous changes in style. We find it downright impossible to repeat any" Schoenberg said. as a man develops between his fifteenth year and his fortieth. In fact we have to break new ground with each work: each work is something different. the minor subdominant (F minor in Q. they happened to us unselfconsciously and intuitively. How do people hope to follow this? Obviously it's very difficult. but stylistically there were no changes. even though a quarter of a century has gone by since then.that gradually a piece definite was written.
In fact there was no longer any reason to return to the basic key. scale is complete." example you will find very striking is the end of Brahms' The cadences found here are astonishing. If we do this for each degree of the scale. and so is the way its really remarkable harmonies already take it far away from tonality! An Johannes Brahms. and that meant the end of tonality.take the relationships of the individual degrees in various ways. major. what emerges? The chromatic C D scale and the twelve-note sharp). F sharp-A fiat-C-D I can exploit the double meaning of all these chords so as to move elsewhere as fast as possible. " Parzenlied. one is D. Parzenlied. the other there isn't merely one supertonic but two. end of work 46 . After all. in flat. is Another means of modulation the augmented five-six chord (in C major.
that's to say the path where one moves by semitones. The chromatic path. Such chords could be used without preparation and without resolution. Last time we discussed chords built at a six-note chromatic passing chord from the whole-tone scale. (22nd January. Commissions went out. for instance. Franz Schreker. The content is catastrophe. to Richard Strauss. The whole-tone scale consists of only six notes. The whole-tone scale: it's nonsense to believe this originates in Oriental or Far-Eastern music! Its origin is simply and solely the urge for expressiveness (" Hoiotoho!" in Wagner's " Walkiire "). never calling things by their right name using one substitute after another for the basic chords preferring to leave open everything that's implied. So a state of suspended tonality was created. really dead. or E flat47 . 34. for example. that's the nature of twelve-note composition! " " To illustrate this. and arrived (F-A-C sharp-G-B-D sharp.So it was not a matter of someone's saying. there's I want to prove to you no point in going on dealing with something dead. and intuitive discovery. " Any kind of unity is possible!" This way of circling Schoenberg said. All twelve notes came to have equal rights. Wagner. Music for a Film Scene (Op. written Schoenberg's publishing house in Magdeburg had commissioned " " A a number of prominent composers to write music to accompany a film scene. Once that's proved." and in Schoenberg's orchestral work with the same title. panic fear the sense of everything that happens as the music (29th January. Something else eating away " the old tonality! Its first use in six-note chords was by Debussy in Pelleas and Melisande. and also to Schoenberg. In Wagner. Their origin is melodic. In the end our ears no longer made us feel we had to intervene. had begun. 1932) IV Today we that it's shall examine tonality in its last throes. harmony is of the greatest importance. unfolds. " How would it be if we did without tonality?" There was prolonged and careful consideration. and This is roughly: threatening danger. 1933) m Brahms is a much more interesting example than. The cliches simply disappeared. in 1930) will be played. but Brahms is in fact richer in harmonic relationships. actually to introduce the keynote.
bringing the colossal impression. You see. the purely theoretical side had given out. The tonic itself was not there it was suspended in space. On my way there I decide I'd rather I act on the impulse. go on in America! lliat's modulation! travelling and finally end up out. Schoenberg called on ZemUnsky for help. Relationship to a keynote became ever looser. look what else happened! Schoenberg's Song Op. It was unendurable. it We Berg and I will get into my biography. and immediately felt You must write something like that. it would already have been disturbing if one had truly taken one's bearings by the tonic. get into a tram. especially at the end. music by Schoenberg that's no longer in any key. Now you have an idea how we wrestled with all this. and he dealt with the matter negatively. Then I was supposed to write a variation movement. but I thought of a variation theme that wasn't really in a key at all. Indeed I did go on to write a quartet in C major but only in passing. the chosen keynote. stay in the country. the song has two " In diesen Wintertagen " (C major). I finished the movement it was still related to a key. everywhere we see the unity with what happened earlier. Every time we pupils came to him something else was there.G-B-A-D With flat-F). It was frightfully difficult for him as a teacher. 14: "Ich darf dankend an dir niedersinken " (last bar in B minor. I'd been his pupil for " three years. This opened the way to a state where one could finally dispense with the keynote. 1908. too!" Under the influence of the work I wrote a sonata movement the very next day. we approach the catastrophe. all this Simply by adding one such chord to another that's we produce a twelve-note chord. Schoenberg's Chamber (fourth-chords 1). but in a very remarkable way. 1906. The possibility of rapid modulation has nothing to do with this development. it's completely clear. It made a In that movement I reached the farthest limits of tonality. I say this. By pure intuition. not so that but because I want to show that it was a development wrested out of feverish struggles and decisively necessary. At that time Schoenberg was enormously productive. his uncanny feeling for form had told him what was wrong. to extend tonality we took steps to preserve tonality we broke its neck! go go out into the hall to knock in a nail. sharps in its key-signature). In 1906 Schoenberg came back from a Chamber Symphony. so to speak" suspended tonality !" But it was all still related to a key. On the contrary. is invisible. Both of us sensed that in this sonata movement I'd broken through to a material for which the situation wasn't yet ripe. come to a railway station. in order to produce the tonic. amid frightful struggles. went through all that personally. analogously constructed. in fact. no longer needed. invisible. nicht Now 48 . just Symphony because all this precisely because I went on in order to safeguard the keynote. The key.
the George songs it would also be possible to make out a key. especially toward the end." So there's nothing new here. 15. it need hardly be used to emphasise. one could conceivably take it as major chord at major and add a recall the first n G G the end. (4th February. everything hangs together. n and V: no more return to the tonic. " Even if we still have at the end to produce a relationship to the tonic. 15! Nos. . No. YE Only the means used are different. George-Lieder Op. In the end we said to ourselves. 14 (" Ich darf nicht dankend . To anyone with a refined sense of form it was all over. No. In No. is * This is the end!* Anyone can tell when a piece over. The song returns to its opening. VII (accompaniment for one hand alone). the way Schoenberg returns at the end to what happened at the beginning! Arnold Schoenberg. of with a key-signature of two sharps and still ending in B minor. knows where Now let's look at Schoenberg's George songs Op. no-one the one ends and the other begins. anyway. "). and a repetition would sound trivial to anyone of sensitivity. 1933) Clearly this period really started with the George songs Op. everyone feels the end anyway. .Here we do still find a key but no cadence. You'll song of Schoenberg's Op. 15. 49 .
the passage remains obscure. flat it doesn't close in any key. and the in bar 12 of the first piece. how does Schoenberg come to end with the has everything that happens to do with E flat? problem by coming at it One must * In fact try to solve the from all sides. As flat comes as early as bar 2 of this piece. and that in fact it's impossible to fix a dividing line between old and new. It has been suggested that " " " " Webern's No. 15. except No. 2 mean that he was making two separate points. flat E occurs E 50 . 11: three piano pieces (written about 1908). Schoenberg's Op. No. we still find the very important factor that governed music for centuries this exploitation of relationship to a key.'Sen -sou. E How E No. There's hardly a single consonant chord any more. 2: 1 ask in the bass note E flat? What first same way. partly to demonstrate again how gradually the change came about. up to bar 13 every note in the chromatic scale flat!* occurs. Let's look at the opening.B. 1 and No. L.unct die aold-nert Bin. this reference to a tonic is meant to show how much all these changes still took place within the bounds of harmonic progression. Rather than answer the question at once I want to show you some more examples. 1 : ends on The final bass note is does the piece come to have E flat as a tonic? the fundamental. Arnold Schoenberg. 11 Why is it still so there. both about the second piece. Please understand. But thoug-h things had gone so far. George-Lieder Op. and not so any longer here? What's the explanation? This question really takes us into the inmost mystery of twelve-note music.
" incredibly difficult. none of " of them may occur again. but had been sensing it for a long time. That makes twelve notes: none is repeated. 12. D minor (the keynote could also be B quite feasible. The whole course of the piece shows could be flat. At we were not conscious of the law. This relationship was always there up to now. The inner ear decided quite rightly that the man who wrote out the chromatic scale and crossed off individual notes was no fool. " about 1911 1 wrote the Bagatelles for String Quartet " (Op. is related to the What. (Josef Matthias Hauer. Why? Because I had convinced myself. the piece is over. does this show us once again? One's tonal feeling is aroused." We It had to be given its due that was still possible at this stage. It isn't easy to talk about all the things we've been through! There we still see the key given. It was so ambiguous. the B flat in the bass (B flat triad!) is in fact there." that the note " came through. Here " I had the feeling. too. then " Gleich und Gleich " in 1917) begins as follows: G sharp -A-D sharp -G. 4. all very short pieces. but it proved disturbing. incomprehensible. went through and discovered all this in his own way). composed sharp-B-F-C sharp. An inevitable development of this law was that one gave that time F 51 . lasting a couple of minutes perhaps the shortest music so far. then a chord E-C-B flat-D. then. Are these chordal progressions the right ones? I putting Am down what I mean? Is the right form emerging?" What happened? I can only relate something from my own experience. My Goethe song. if one note occurred a number of times during some run of all twelve. and it was been there already. but with chromaticism. "This note has It sounds grotesque. until all twelve notes have occurred. D-F-D at the beginning that D quite clearly how through its entire layout everything tonic E flat: but this E flat is not introduced as tonic. in some way " got its own back. Things have asserted themselves that made this "key" simply impossible. either directly or in the course of the piece. for example. In this musical material new laws have come into force that have made it impossible to describe a piece as in one key or another. sensed that the frequent repetition of a note. The most important thing is that each " run twelve notes marked a division within the piece. In short. and is held for three bars. Then in bar 16 there's a second idea which though not in major does approach the key." Much later I discovered that all this was a part of the necessary development. When all twelve notes have gone by. (Four Songs Op. No. One day Schoenberg intuitively discovered the law that underlies twelvenote composition. 9). idea or theme. " The most important thing in composing is an eraser!") It was a matter of " constant testing. Individual parts in a polyphonic texture no longer moved in accordance with major and minor. a rule of law emerged. here we don't see it any more. In my sketch-book I wrote out the chromatic scale and crossed off the individual notes.following explanation is but the B flat never flat comes). (Schoenberg said.
All twelve notes have equal rights. at the goal. soon there was an thematic. Twelve-note composition is " " not a substitute for tonality but leads much further. mirror canon). and which in Beethoven became most important variation form. Mahler. What is a canon? piece of music in which several voices sing the same thing. the twelve notes have come to power and the practical need for this law is completely clear to us today. note-repetition that's forbidden.Imagine. Schoenberg's string quartet (in minor) the accompanying figure is thematic! This urge towards unity. i. There's no longer a tonic. (12th February. too. etc. This proves that it really did develop quite naturally. based on a fugue theme (answer. One means of doing it was tonality. all that follows is derived from this idea. often what is sung occurs in a different order (crab canon. which is the primeval form. An example: Beethoven's Ninth Symphony. The crowning glory of polyphonic music was the fugue. It is varied. but it is unity. it was the same thing but differThematic unity came with homophonic music. only at different times. an urge to deepen and clarify the unity. finale theme in unison. 1932) VI Before we knew about the law we were obeying it. Unheard-of things happen." Theme: example: Beethoven's C-F-G-A-F-C-G-F. is really Now something very remarkable emerged. One of the earliest surviving polyphonic pieces is a canon an English summer canon from the 13th century. but the fugue.). Indeed. yet again. We can look back at its development and see no gaps. ent! A Why does this crop up again? Six easy variations on a Swiss song. and yet it's constantly the same thing! first D A 52 . Schoenberg. theme is given. twelve parts. If one of them is repeated before the other eleven have occurred The twelve notes. then backwards! You won't notice this when the piece is played. the succession of twelve notes a particular order. leads of its own accord to a form the classical composers often turned to. In this sense variation form is a forerunner of twelve-note composition. and perhaps it isn't at all important. in a firmly fixed it would acquire a certain special status. Great composers have always striven to express unity as clearly as possible. order. form the basis of the entire composition.e. Another was provided by polyphony. but within the order fixed by me for the twelve notes none may be repeated!) Today we've arrived at the end of this path. and each of them has begun the series of twelve notes! (It isn't sixty parts. relationships. An " Further development of unity in Brahms. stretto. attempt to create some kind of unifying thematic connection between the principal part and the accompaniment We see an absolute pull from homophonic music back to polyphony.
one composes as before." Something will stick in even the the Sonnet from Schoenberg's harm done So there will be a multiplication of all the things that were naivest soul. (19th February. The most comprehensive unity results from this. felt in a way. Goethe's primeval plant. (Here too the result can be rubbish. 1932) vn Last time. canon form we mentioned last time: everyone sings the same " Shut the door. too. So an idea should be presented hi the most multifarious way This urge to create unity has also been the Remember possible. which is at the bottom of everything. is backwards movement cancrizan. An ash-tray. ** This path How has such an unusual degree of unity come about in twelve-note music? Through the fact that in the course of the row on which the composition is based no note may be repeated before all have occurred. If I repeat several times. The course of the row can be repeated several times. as Schoenberg said about thing. another is mirroring The development of tonality meant that these old methods of presentation were pushed into the background. there's no in tonality. Something that seems quite different is really the same. This law developed gradually. " felt by all the masters of the past. in thematic development. but they still make themselves One such way inversion. even quite identically. even in classical times. is always the same." or. a questionable composer. found its fulfilment. " I am an ass. All the works created between the disappearance of tonality and the formulation of the new twelve-note law were short. seen from all sides. on its own. strikingly short. The longer works " " written at the time were linked with a text which carried them (Schoenberg's 53 . the stalk no different from the leaf." then unity of that kind is already established.You'll already have seen where I am leading you. but on the basis of the row. unity was mostly felt only unconsciously. For the rest. the root is in fact no different from the stalk. and the leaf no different from the flower: variations of the same idea. and yet different. starting from Goethe's "primeval plant." led to every-increasing refinement of the thematic network." The same law applies to everything living: variations on a theme "that's the primeval form. as in tonal composition: nobody blamed major and minor for it!) If an untutored ear can't always follow the course of the row. bound up with the urge toward thematic development. as in " Serenade. on the basis of this feed series one will have to invent." we dealt with the *' other path. aimed at along the second path. but it would have been impossible without using both And here the urge toward maximum unity the paths we have described.
At the time everything was in a state of flux uncertain. that's to Die GluckHche Hand. the result of chance. Considerations of symmetry. adherence. With the abandoning of tonality the most For tonality was important means of building up longer pieces was lost. the idea was then subjected to careful thought. dark." Berg's and Erwartung say. However much the theorists try. is so powerful that one has to consider very carefully before finally committing oneself to it for a prolonged period. for example one aims at as many different intervals as possible. same key!" This analogy with fostered. inversion. inversion of the cancrizan. itself Each of these four forms can be based on each of the twelve degrees of the Bearing these twelve transpositions in mind. etc. (thrice four or four times three notes. I should like to say something today about the purely practical application of the new technique. scale. groupings Our Schoenberg's. the recapitulation will naturally return to it. How is the system now built up? Our inventive resourcefulness discovered the following forms: cancrizan. " supremely important in producing self-contained forms. one works as before. regularity are now to the fore. Only when Schoenberg gave expression to the law were larger forms again possible. or certain correspondences within the row symmetry. each row can manifest in 48 different ways. very stimulating and exciting. it's How Adherence is strict. Inspiration. a difficult moment! Trust your inspiration! There's no alternative! So the row is there. and we didn't create the new law ourselves it forced itself overwhelmingly on us. (At least this is how it strikes us now). for instance). development starts. does the row come to exist? It's not arbitrary. linked with an intuitive vision of the work as a whole. subdominant. arranged with certain points in mind. As if the light had been put out! that's how it seemed. Berg's and myrows mostly came into existence when an idea occurred to us." " " Wozzeck "). At once re-casting. as against the emphasis formerly laid on the principal intervals dominant. often burdensome. There aren't any others. But first I'll answer a 54 . if you like. The original form row occupy a position akin to that of the " main key " in " in the music. analogy. but it's salvation! We couldn't do a thing about the dissolution of tonality. This compulsion. so that there wasn't time to notice the loss. 1932) VIH Linking up with my last remarks. Four forms altogether. We end important. mediant. here we find earlier formal construction is quite consciously the path that will lead us again to extended forms. For this reason the middle of the octave the diminished fifthis now most and pitch of the earlier For the rest. almost as if taking the decision to marry. Here there are certain formal considerations. (26th February. with something extra-musical. just as one can follow the gradual emergence of themes in Beethoven's sketchbooks.
there seven: our adherence to the row is indeed a particularly strict adherence. so that in a sense it's the dominant of the first part (" tonic "). it destroys constantly comprehensibility." But I can also work as a rule. adhering to nothing except the row. Op. Only now is it possible to compose in free fantasy. Bach wanted to show all that could be extracted from one single idea. From bar 8 onward the notes are differently distributed among the individual instruments. (Naturally any note can also occur in whatever octave one pleases. In bar 7 the cancrizan of the row occurs in the flute part. In the third movement the row is at first divided between horn and bassoon. with a certain regularity the horn picks out notes of the row for its melody. Only after the formulation of the law did it again become possible to write longer pieces. We that way. " " In this sense the Art of Fugue is equivalent to what we are writing in our twelve-note composition. Schoenberg's Wind The row is Quintet. " As an example. At least it's impossible to write long stretches of music in The twelve-note row " is. This is how unity is ensured.How is free invention possible when one question put to me by one of you: has to remember to adhere to the order of the series for the work?" Strictly speaking. J. but adherence of this kind has always existed. theme. or a fifth higher if you like. Practically speaking. S. in the strict polyphonic forms such " as canon and fugue. One invents on this new basis. here the chromatic scale. and the second of which lies a fourth lower. " What can I do with these few notes?" There's forever something different yet the same. Here we find that pedal-like repetitions of the same note don't infringe the basic law. What else could this work be but the Fugue answer to the question. which are tied to the chosen theme. because of the unity that's now been achieved in another way . To put it We want to say " " 55 . what has been said before. something surely sticks in the ear. the answer might be this: "Couldn't one ask the same question about the seven-note scale?" Here twelve notes are the basis. and we've often found that a singer involuntarily continues the row even when for some reason it's been interrupted in the vocal part. even if one's unaware of it. In Bach it's the seven notes of the old scale that are the basis. that's to say much more freely. One can see at a glance that the row falls into two parts that are of parallel construction as regards intervals. the row ensures unity. the details of twelvenote music are different. But now in a quite new way I can invent more freely. B flat-D-E-F sharp-A flat-F. everything has a deeper unity. 26: E flat-G-A-B-D flat-C. Bach's Art of " is based on a single theme. but as a whole it's based on the same way of thinking. not a without thematicism. As we gradually " don't want to repeat. there must gave up tonality an idea occurred to us: " be something new! Obviously this doesn't work.) So this is the ** primeval plant yet always the same! " we discussed recently! Ever different and Wherever we cut into the piece the course of the row must always be perceptible.
In the accompaniment to the theme the cancrizan appears at the beginning. since it enhances comprehensibility. When this true conception of art is achieved. Even the Netherlander didn't manage it. and then I look for the right place to fit it in. The first variation is hi the melody a transposition of the row starting on C. I know how I invent a fresh idea. This is a particularly intimate unity. written in 1928). So the entire movement is itself a double canon by retrograde motion! Now I must say this: what you see here cancrizan. canon. and you must allow that there are indeed many connections here! Finally I must point out to you that this is so not only in music. now an inversion? Naturally that's a matter for reflection and consideration. So here there are only 24 forms. that would be ludicrous. constantly the same thing isn't to be regarded as a "tour de force". the greater becomes the identity of everything. I was to create as many connections as possible. This variation is itself the midpoint of the whole movement. We find an analogy in language. 1932) 56 . is F-A flat-G-F sharp-B flat-A. etc. It's peculiar in that the second half is the cancrizan of the first.quite paradoxically. unity also has to be created there. and how it continues. and it's our faith that a true work of art can come about in this way. 21. then number forty-five. ! The row An example: the second movement of my Symphony (Op. It's for a later period to discover the closer unifying laws that are already present in the works themselves. He even turns a phrase backwards. in alliteration and assonance. after which everything goes backwards. The old Netherlander were similarly unclear about the path they were following. And I leave you with an old Latin saying: SATOR AREPO TENET OPERA ROTAS (2nd March. since there are a corresponding number of identical pairs. then there will no longer be any possible The further one presses distinction between science and inspired creation. now a cancrizan. Greater unity is impossible. only through these unprecedented fetters has complete freedom become possible! Here I can only stammer. How does a man keep the 48 forms in his head ? How is it that he takes now number seven. In the fourth variation there are constant mirrorings. Everything is still in a state of flux. I was delighted to find that such connections also often occur in Shakespeare. forward. The accompaniment is a double canon. Karl Kraus' handling of language is also based on this. and " Here Harmonielehre" in the end this development led to Schoenberg's there's certainly some underlying rule of law. E flat-E-C-C sharp-D-B. and finally we have the impression of being faced by a work not of man but of Nature.
* Ger. An important saying of Schoenberg's : compression always means extension ! " " and " development " of themes."* less ** Mozart and Haydn have they already create room for all gardener digs a furrow where he buries his shoots. than Beethoven. Of my notes. that during the analysis he had in fact realised that the second movement of his quartet was formally an exact analogy with the Beethoven Scherzo. We analysed classical works almost exclusively. 2. 14 No. I used to go once a week to his flat in Maria Enzersdorf. He said of the latter. 57 . the thematic side is secondary. just as the " Not until fected. I shall here quote only a few that are of very general importance. 22." The magic square in things) which Webern arranged the saying clearly shows the basic principle of twelvetone technique the equal status of basic set. But thematic exactness that happens in sonata form. What has twelve-tone technique to set against this? To develop means " to lead through wide spaces. " To supplement the lectures I should add a number of notes I made between September 1936 and February 1938 when I was working my way through the theory of form as Webern's private pupil. (Bach Distinction between unfolding and Beethoven). " DurchJf tihrung " ("leading-through") * the "development section" in sonata form.*' with which Webern his lecture on March 2nd. 21 and his Quartet Op. cancrizan and inverted ended cancrizan. 1932.POSTSCRIPT The old Latin saying Sator Arepo Tenet Opera Rotas. only twice did he talk at any length about his own works about his Symphony Op. In tonal music. in Schoenberg they serve to produce relationships of content. could be translated as (among other " The Sower Arepo Keeps the Work Circling. when we were analysing the Scherzo of Beethoven's Piano Sonata Op. above all in Brahms. then there is Beethoven is the horizontal presentation of musical ideas pera move backward. near Modling. variation is possible by merely altering the inversion or spacing of chords. inversion. and on my way back in the train I always hastened to jot down my experiences with Webern. In his music the independently developed subsidiaiy parts determine the character of the theme. which fill a whole notebook. The primary task of analysis is to show the functions of the individual sections.
I had hoped to be able to go through it with him here The piano score of my choral piece ("Das Augenlicht") was published recently (UE). Now indeed I'm eager to know whether the B. More. less. Nobody from here can go. serial technique. 1938 and 29th April. Examining the development of variation technique one has direct access to Relationship to theme or row is quite analogous. .e. About rondo form: original character of a light closing sible. Its future and that of the Association are uncertain for the time being. Festival in from the Austrian section. festival (I. six-part Ricercar its Example: the " from the Musical Offering. Will you be going there? You did once say you meant to. at the moment I've only one pupiL You have to be patient! . chorus will learn it. As a personal July 6th.B. . At the moment I am solely responsible for signing everything . So already I .VI in the first concert of the London). because the whole is more strictly tied to the row. In studying form one ought really to take variation form as early as posSchoenberg thought so too. . friends. Did you hear about the awful thing that happened when my string trio was " performed in London? The cellist got up saying I cannot play this thing!" and walked off the platform! Surely nothing like that has ever happened . i. This time there won't be a ** delegate " is ductor to be Scherchen. from our friends? Do write again very soon.M. the parts to Kolisch in London. Just in the last few weeks I've been hard at work and have completed my string quartet (Op. But the firm- ness of a codetta. 58 . because the row gives fewer possibilities of variation than the theme. In Brahms and Bruckner this happens through the introduction of developing (contrapuntal) elements. 1944." development tends to take away from the rondo its movement. . I did receive an invitation but I shall hardly be able to get away.S. recollection of my from the thirty-one letters I received dear master and friend. hence the use of rondo form for middle movements as well. The conPlease send to hear me a from one's lot of news and write often.The contrast between firm first and loose is a fundamental one. subject (presentation of the theme!) is different from that of a Even in Bach's fugues this contrast can be seen in the episodes.C. . In any case it's forbidden (by law) to call itself "Austrian" any more.C. 1938 Now of all times one needs was eagerly expecting your news. in Mahler new ideas are unfolded in the episodes. Performance 17. Now it's off to America. before! What else do you hear from the world. 28). some quotations from him between April 29th. But Schoenberg once said: the row is more and less than a variation-theme. too. It's a business with my teaching.
.21th July. 1939 Yes. 2. But they'd just be totally misunderstood. which songs were you thinking of? It's very important to choose the right ones. from Op. Well. It's very hard for performers and listeners to make anything of them. I too believe it would be best for you and yours to stay where you are in the present circumstances. Let's hope.. Very good. 12.II under Erich Schmid (in Winterthur) . cause me constant concern and oppress me beyond measure! But we do have a " foothold " and in my opinion an impregnable one. so I have never for one single moment lost heart (either on my own account or in my worries about others!). 4.M. everything I've mentioned is thirty years old already! And still " have to worry! As if it were a matter of world premieres. dear friend! was very pleased to have your news about the performance of my Passaon the 7. my dear Reich! Thank you very much! Anything of the sort did seem quite out of the question for me! I take it as a good omen! cagjia Now." Der Tag ist vergangen and gang. and that perhaps it was just as well that what you once intended didn't come about. (in Basel).e. in fact! certainly work! Look. E..C. W. Rest assured that all these difficult problems are very much on my mind. " So ich traurig bin " (that has never yet been sung!) or Ein" " " Gleich und Gleich. " from Op. that makes all the difference. I * Dr. That would be a group of 5 songs that ought to come in that order! As far as instrumental pieces of mine are concerned. 4 and 5! That would Otherwise the violin pieces would be a better idea than the cello pieces. long time yet (i. So I should set great store by its coming off! I am delighted that you thought of that piece. look.. Seen from " '* " " this foothold the authorities you mention (that's what one has to call " them!) have always looked to me like ghosts!" I Can for what 2Qth October. In certain circumstances my visit could even be of far-reaching importance for me. If an invitation to me could be arranged I should be very glad and should naturally come very gladly \* . if there were a quartet that would 5). So I wish you as long a stay as possible." from Op. As far as I'm concerned." "Kahl reckt der Baum". 3. Dear friend. We spent some memorable hours with Webern in Winterthur and Basel in February 1949. But maybe things I will change again after all. 59 . until you find something more like what you want). then perhaps Nos.R.g." If only I could at last be understood a little! But what you are doing is splendid! So About your lecture: nothing theoretical! keep my suggestions in mind. Definitely not those! Not because I don't think they are good. Werner Reinhart arranged the invitation.. Nothing experimental! Create a favourable atmosphere for the performance of the Passacaglia! play if not all 5 movements (Op. "Dies ist ein Lied. the concert planned for the LS. 1939 perhaps be of assistance? You surely know you can count on me my feeble powers are worth! Let's hope you'll be able to stay where you are for a long.
9th December. . Already there are all sorts of things to write about it it. now I have to do work for the U. Now I'm preparing the score. thick vocal score.Rather say how you like this music! People makes a good impression . " " " overture is basically an adagio "-form. I was left out in the cold! So I had to take what there was. long time.. . but sometimes with the effect of a sostenuto. I had to put off work on the Cantata (Op. Now. I beg all could be taken of my work ! The third movement. 1939 wanted to reply at once. Beethoven's Prometheus and Brahms* " Tragic" are other overtures in adagio-forms. I settled on a form that amounts to a kind of overture. But now it's ready. . . Yet it's a strict fugue... but U. But the subject and counter-subject are related like antecedent and consequent (period). otherwise might already be finished. cl. trmbn. . tuba. 29) is now complete part double fugue. But I hope it will be possible quite soon. but there were reasons. If only some notice at * dear chap. the post was liquidated. ''Variations for Orchestra" (Op. quickly! It's a devil of a situation.. I haven't written to The piece lasts around quarter of an hour. trp. in September I lost my steady job at the Radio. the Cantata (Op. eel. I think. str. For choir. my of you. The orchestra is small: fl. timps. but the recapitulation of the first subject appears in the form of a development. And now. 30). because I was again so very glad to have your November 2nd). . will surely make it available as quickly as vertical in all other respects. alas.. More about this work next time. I sat there for weeks and weeks. ob.E. a thick. (with double bass). and that's also the title. And I wouldn't and couldn't do anything else. and that Imagine. (I'm not telling more for the time being!) Yes. I think I even said so to you.. bass cl. harp. not sonata form! . One could also speak of a scherzo... orchestra. say your piece and exert your influence. in general and in particular. 1941 you for a long. will believe it from you. soprano solo and also of variations! I letter (of . At the moment I haven't a single pupil. In fact there's again the synthesis.. but not that it would need that amount of time. the presentation is horizontal as to form. 29) for a time. but based on variations. something quite simple and perhaps obvious has emerged. but I was quite buried hi It's* constructed as a fourmy work.E. " " so this element is also present. and elements from the other mode of presentation (horizontal) also play a part. hn. So. March I 3rd. My possible. There isn't a copy ready yet. very quick tempo almost through- out. 60 ... Certainly I'd sensed that it would be difficult. except things that absolutely couldn't be postponed. In fact needed that long to get to the end of the score of my orchestral variations.
so that you have counter to possible objections and can throw at least a certain amount of light. etc. So. again. but tries on the contrary to continue it into the future. that doesn't reject the development that came then. that came out very number of things are clearer than in my manuscript. Yes. a new one. a let's hope everything should like else will! very briefly to tell you a little about the work. something " Like Josquin orchestrated? The answer would have to be an energetic no **! What. for instance. building a tonality. I should like to talk quite I an effective differently about it to you personally. and whose formal construction relates the two possible types ofpresentation to each other. Anyway it's impossible to ignore them. 1941 The copy of my Variations is ready it's a photocopy. But a few briefly. Why.May 3rd. then? I believe. if there is still to be meaningful expression in sound! But nobody. So point one of the whole affair is approaching completion on time. that's to say. So do understand me aright. and doesn't aim to return to the past. is going to assert that we don't want that! So: a style. and tonight Schlee himself is taking it with him to Switzerland a particularly good idea for reasons of safety. then? Nothing like any of that! Now you would have to say unequivocally: this is music (mine) that's in fact based just as much on the laws achieved by musical presentation after the Netherlanders. Correct! But that in fact touches on the first Won't the reaction when they " ' most important point: it would be vital to say that here (in my score) there is indeed a different style. many notes they're used to seeing. but one that uses the possibilities offered by the nature of sound in a different way. whose material is of that kind. really. preceding forms followed tonality. What kind of style. Now I should be glad to explain the piece to you from the score. namely on the basis of a system that does " " relate only to each other (as Arnold has put it) the 12 different notes customary in Western music up to now. well. but doesn't on that account (I should add to clarify things) ignore the rules of order provided by the nature of sound namely the relationship of the overtones to a fundamental. Strauss. important things still. in R. 61 . nor does it look like Bach. but what sort? It doesn't look like a score from before Wagner either Beethoven. when opportunity see the score be offers. there's nothing there '"!!! Because those concerned will miss the many. as the earlier. Exactly following natural law in its material. Is one to go back still further? Yes but then orchestra! scores didn't yet exist! But it should still be possible to find a certain similarity with the type of " " archaistic ? presentation that occurs in the Netherlanders.
on the basis of the law of the row. but rhythmically augmented. which unfolds in full. But through all possible displacements of the centre of gravity within the two shapes there's forever something new in the way of time-signature. 1941 I'm terribly sorry to be so long answering your long. Six variations follow ceived as a period. etc. it is con" '* in character. But it's reduced still more. Simply compare the first repetition of the first shape with its first form (trombone or double-bass!) And that's how it goes on throughout the whole piece. the fourth the recapitulation of the first subject for it's an andante form! but in a developing manner. the The "theme " fifth.of the Variations extends to the first double bar. so. if at all. the third the second subject. but is introductory one to the next double bar). the two tempi of the piece as well (pay attention to the metronome marks!). I think. In miniature! that's to say the row. Now. a recitative! But this section is constructed in a way that perhaps none of the " Nether" landers ever thought up. this first piece is complete and even written down in score. it But I must stop here! All the same I shall be glad to say more about another time. I've been completely absorbed in my work (2nd Cantata. it was probably the hardest task (in that respect) that I've ever had to fulfil! a four-part canon of the most complicated kind. the first Now But the succession of motives takes part in this cancrizan. the second two notes are the cancrizan of the first two. whose twelve notes. formally it's an introduction. The first piece in a new choral work (with soli and orchestra) that may well go beyond the scope of a cantata at least that's my plan. And I'd like to tell you a little about it straight away. that was quite something. welcome letter. everything that occurs in the piece is based on the two ideas given in and second bars (double bass and oboe!). see. But was only possible. by a repetition of the first shape (double-bass). that's to say motivic variation happens. 31) and still am. but in diminution! And in cancrizan as to motives and intervals. August 23rd. The first bringing the first subject (so to (each speak) of the overture (andante-form). That's how my row is constructed it's contained in these thrice four notes. In fact this may well be the first time it's been so completely operative. which is quite particularly in evidence here. They are followed. leads to the Coda. repeating the manner of the introduction and bridge-passage. Don't be offended. though with the use of augmentation and diminution! These two kinds of variation now lead almost exclusively to the various variation ideas. only within these limits. contain its entire content in embryo! With bars one and two. the basis is it's You the way carried out 62 . on the trombone. since the second shape (oboe) is itself retrograde. the second the bridge-passage. character. sixth variation. Op.
one can straightway invent plants ad infmitum to apply to all other living matter at its deepest? " ! Isn't that be found the meaning of our law of the row. The foundations of our technique hi general are there. 30 in Winterthur 63 ." But again those relationships orchestra.I read in Plato that " Nomos " (law) is also the word for " melody. conceived rather as a * The planned performance of the finally took place on March 3rd. it. and that on December 9th. but I think I'm returning to them in a quite special sense. When one's faced.E. then you do right! Revel in sounds. 1942 I can report that I've made another fair step forward. conductors. I'd love to believe that things will stay Variations (Op. . 1942 " " So now a the way Scherchen performed news!* positive success is in sight. the melody "! But since in my case it in fact is. . It's a soprano aria with chorus oratorio and orchestra. one's thoughts are mainly (and naively) how will it sound? And one enjoys it in advance. then there must also be the right sensory impression. It's to form the first part of the planned "oratorio. voice gives out the law in this case the soprano soloist " " that's to say the but the Greeks had the same word for that as melody " Nomos. have already started preparing the material. The same law will July 31st." together with the preceding ones. now the Collegium Musicum should order it from them. another piece of the planned " is all in order and down on paper. truly the Nomos!" But agreed on in advance on the basis of canon! row hi itself constitutes a law. It's for choir and " chorale. the row takes on a quite special importance. equally naively! But when one actually performs. nothing happens any more unless it's agreed on in advance " " according to this melody "I It's the law. but at least I've recognised what's involved! In my case. only always been in music by the masters! Whether I shall bring God knows. melody the soprano soloist sings in my piece may be the law (Nomos) for all that follows! " " As with Goethe's " the as the introduction (recitative) primeval plant with this model. My " A That's it how it's off as they did. Everything going as well and pleasantly as last time dear fellow ! ! cheering thought ! it's a very My ! The U. time has been wholly taken up with it lately. " 4th September. by a first performance. and the key to . . especially orchestral." for law: So the " melody " has to " lay down the law." Now. " Variations for Orchestra 1943. you Meanwhile I've completed another piece. on a higher level so to speak. rather like the chorale melodies in Bach's arrangements. . " Op. but it needn't also be the Naturally. 30) will really be told you." About my work. You can imagine how pleased I was about your my .
for which many thanks again! But this is how it was. I think the look of the score will amaze you. Whichever suit Frau Gradmann best. so. three and four (cancrizan). 5* " But formally the Art of Fugue. but once again I've hardly taken my told eyes off my work. It's all even stricter. 27) between them. I think it would be best to put these songs in the middle of the programme. 23 and 25). Because it was very important for me to check personally what it proves and I believe I was right. Before and after this group. It's a three-part chorus for women's voices with soprano solo and orchestra. I really didn't mean to make you wait so long for an answer to your letter of August 30th. etc. with a c. 4 and 5 of Op. giving me tremendously difficult problems to solve. 1943 I'm very sorry to be so overdue. and to play the piano variations (Op. 1. a double interlinking. one and four. . a bass aria. which have just appeared (in print). you directly I wanted to say a number of things to on my return from Winterthur. " Die Stille um den Bienenkorb in der Heimat" still sorry that hardly able to talk to each other alone! It did me a lot of good to be able to hear my piece. once again. 4 and 12. Hymn-like character. I move with complete freedom on ** the basis of an endless canon by inversion. a selection from the songs with piano Op. What you say about my orchestral variations gave me very genuine and equally so your plans for getting my music performed . I'm this time we were public also proved this! October 23rd. rather as Bach does with his theme in the aria is ternary. 6 in all (3 in each of Op. 3 (as far as Fm concerned those are 64 . even the most fragmented sounds must have a completely coherent effect. Another piece will soon be my finished. I've completed another piece as part of the plan I've you of several times. pleasure. but moreover sings the notes of the third backwards! So. the third (soprano) has the inversion of the second. and the fourth (bass) is the inversion of the first. Long note-values but very flowing tempo. and leave hardly anything to be desired as far as " " is concerned. I'm buried in work. a very close combination of the two types of presentation. 1943 Dear friend.the second part (alto) sings the notes of the first (tenor) backwards. also one and two. diminution.32-bar theme of periodic structure. 3. 23. and for that reason it's also become still freer. namely that when that kind of unity is the basis. two and three (by inversion). Perhaps begin with Nos. That's to say. Isn't that so? I believe the effect on the comprehensibility But I really must revert to the subject of Winterthur. I'm all for the idea of giving the first performance of these songs (even they are nearly ten years old) at the concert you plan in Basel ." By variation. When I was with you in March. . Frau Gradmann already had the 3 Songs Op. as you know. August 6th.
for goodness' sake! Please do fall in with this request! January 10/A. which I organised. You're anxious to know what happened here for the 3rd ML. your kind telegram. your letter. the piano variations Op. 2 and 4 of Op. how irrelevant. it would then last about an hour. whichever of Op. So for once on a Friday (course day) evening we had something rather more enjoyable than the usual intellectual refreshment. 12. 4 she prefers. I'm glad to tell you that for a long time I've been I was very glad full * Webern's 60th birthday.). which gave me so much pleasure. 1943. courageous. how utterly unimportant. and such a magnificent effort that I can't hope to say what I feel about it! So. as has already been seen. 1944 Dear friend. one with consequences). "Du". but I don't think Frail Gradmann has ever sung them). my heart overflowing with the finest feelings! And straight I should also like to express them by calling you it. and that would be quite adequate. the pieces for violin and piano Op. And that could make up the whole programme.. and that your initiative never flags! But above Holderlin all I was pleased on your account.C. now at last I can send my very heartfelt thanks for everything. 27. and perhaps 1. because it again reminded me in the best possible way of something I ought to thank you for once again and very specially. and she came on with us to Rate'. my dear friend.S. self-sacrificing loyalty! This 5th of December in Basel (an afternoon concert of the Basel section of the I. I shall go on and use for it makes things much more friendly. your unflinching. 11 and a brief address by myself. the Apostels and this gave me particular pleasure Frau part Helene (Alban Berg's widow.R.R. no: a performance! Don't even mention it that . I embrace you.) its success. with the first performances of the Songs Op. So two groups of 4-5 songs. December 3rd. we met at " " course those taking Rate' in the evening. 65 . That's how it was! February 13rd. it was in fact the day for the in the course.R. that was yet another gracious deed on your part (and.M. W. to live means to defend a form puts it in some such way. 7. who was all ready with a splendid buffet. only one thing: don't tie yourself to the date mentioned!* Don't make it a direct birthday celebration no. my dear Reich! No longer! As for the date. W. 23. 1944 to have your letter of February 1st! It again showed me how of splendid plans you are. We my wife and I had already been to her in Hietzing in the afternoon. the pieces for violoncello and piano Op.the ones I'd like. W.
W. i. compared with those of judged by the impressions they make. 1944 Naturally you can keep the score of my 2nd Cantata to study as long as you need it! What will you say about it? If. a ** concerto " (in several movements for a number of instruments). and I'm particularly . Webera's last completed work. .f for soprano and bass soli. Sehet. how well it suits the structure of the text. other works lack passage the Greeks. I'd already started to me (I'd sensed it " cantata ": Cantata No.. halves. die Farben stehen aufl" The poetic form will be matched by something correspondingly long and unified. What a lot those conductor gentlemen gards the sound! I can only say miss!" I'm very glad that you're now taking up the cudgels on their behalf! I think people will be amazed! . If I come to write another vocal work it will be quite different! At the moment I'm writing a purely instrumental piece. at least until now they've been infallibility. 2. W. Imagine the effect " in his notes on the translation of Oedipus: Again. . so that the constant regroupings (tutti. possible. choir and orchestra. soli) stand out in a As reIt's indeed turned into something quite new! clearly audible way. on a seventh piece when it became clear already) that the six pieces I'd completed made a musical whole. interested in solving this.R. too. Duration half an hour.on me when I found this intensely interested in this poet. 5* will be sent to you It should be played by as large a body of strings as as soon as possible. either as part of a larger work or on their own. ** Schoenberg's 70th birthday. rather than by their ordered calculus and 9 Need I even say why all the other procedures by which beauty is produced: I was so struck by the passage? The score of my string-orchestral arrangement of Op.e. You'll see. for example. you show them what the score of the sixth piece looks like? The sketches I made for an instrumental piece I wrote to you about them have turned into a setting of a very long poem by Hildegarde Jone: " Das Sonnenlicht spricht. my unspeakable longing! But also my unwearying hopes for a happy future! * 5 Pieces for String Quartet. W. dating t from 1909. How will you celebrate September 1 3th ?** Pass on my deepest remembrances. . May 6th. which possess me night and day. . I made some minor changes of order and grouped the six pieces as a " As for my work. 66 . arranged in 1930.R.R. Again for soli and choir (with orchestra). I decided on the latter.
Webern hoped for was denied him in the flesh by his premature. tragic end. lofty works and his effect on the younger generation have fulfilled his hopes in a higher sense. The " happy " Zurich. end of March 1960 67 . but the present triumph of his uncompromising. Willi Reich. which he foresaw in his humble self-abnegation and proud future assurance.
Printed in England by JOHN BLACKBURN LTD. LEEDS LDC/66 .. | https://www.scribd.com/document/108769505/Anton-Webern-The-Path-to-the-New-Music | CC-MAIN-2017-30 | en | refinedweb |
OverReact
A library for building statically-typed React UI components using Dart.
Using it in your project * Running tests in your project
Anatomy of an OverReact component UiFactory UiProps UiState UiComponent
- Fluent-style component consumption
- DOM components and props
Building custom components Component Boilerplates Common Pitfalls
Using it in your project
If you are not familiar with React JS
Since OverReact is built atop React JS, we strongly encourage you to gain familiarity with it by reading this React JS tutorial first.
Add the
over_reactpackage as a dependency in your
pubspec.yaml.
dependencies: over_react: "^1.0.2"
Add the
over_react
transformerto your
pubspec.yaml.
transformers: - over_react # Reminder: dart2js should come after any other transformers that touch Dart code - $dart2js
Our transformer uses code generation to wire up the different pieces of your component declarations - and to create typed getters/setters for
propsand
state.
Include the native JavaScript
reactand
react_domlibraries in your app’s
index.htmlfile, and add an HTML element with a unique identifier where you’ll mount your OverReact UI component(s).
<html> <head> <!-- ... --> </head> <body> <div id="react_mount_point"> // OverReact component render() output will show up here. </div> <script src="packages/react/react.js"></script> <script src="packages/react/react_dom.js"></script> <script type="application/dart" src="your_app_name.dart"></script> <script src="packages/browser/dart.js"></script> </body> </html>
Note: When serving your application in production, use
packages/react/react_with_react_dom_prod.js
file instead of the un-minified
react.js/
react_dom.jsfiles shown in the example above.
Import the
over_reactlibrary (and associated react libraries) into
your_app_name.dart, and initialize React within your Dart application. Then build a custom component and mount / render it into the HTML element you created in step 3.
import 'dart:html'; import 'package:react/react.dart' as react; import 'package:react/react_dom.dart' as react_dom; import 'package:react/react_client.dart'; import 'package:over_react/over_react.dart'; main() { // Initialize React within our Dart app react_client.setClientConfiguration(); // Mount / render your component. react_dom.render(FooComponent()(), querySelector('#react_mount_point')); }
Run
pub servein the root of your Dart project.
Running tests in your project
When running tests on code that uses our
transformer (or any code that imports
over_react),
you must run your tests using Pub.
Add the
test/pub_servetransformer to your
pubspec.yamlafter the
over_reacttransformer.
transformers: - over_react - test/pub_serve: $include: test/**_test{.*,}.dart - $dart2js
Use the
--pub-serveoption when running your tests:
$ pub run test --pub-serve=8081 test/your_test_file.dart
Note:
8081is the default port used, but your project may use something different. Be sure to take note
of the output when running
pub serveto ensure you are using the correct port.
Anatomy of an OverReact component
If you are not familiar with React JS
Since OverReact is built atop React JS, we strongly encourage you to gain familiarity with it by reading this React JS tutorial first.
The
over_react library functions as an additional "layer" atop the Dart react package
which handles the underlying JS interop that wraps around React JS.
The library strives to maintain a 1:1 relationship with the React JS component class and API.
To do that, an OverReact component is comprised of four core pieces that are each wired up to our
Pub transformer using an analogous
annotation.
- UiFactory
- UiProps
- UiState (optional)
- UiComponent
UiFactory
UiFactory is a function that returns a new instance of a
UiComponent’s
UiProps class.
@Factory() UiFactory<FooProps> Foo;
- This factory is the entry-point to consuming every OverReact component.
The
UiPropsinstance it returns can be used as a component builder, or as a typed view into an existing props map.
UiProps
UiProps is a Map class that adds statically-typed getters and setters for each React component prop.
It can also be invoked as a function, serving as a builder for its analogous component.
@Props() class FooProps extends UiProps { // ... }
UiProps as a Map
@Factory() UiFactory<FooProps> Foo; @Props() class FooProps extends UiProps { String color; } @Component() class FooComponent extends UiComponent<FooProps> { // ... } void bar() { FooProps props = Foo(); props.color = '#66cc00'; print(props.color); // #66cc00 print(props); // {FooProps.color: #66cc00} } /// You can use the factory to create a UiProps instance /// backed by an existing Map. void baz() { Map existingMap = {'FooProps.color': '#0094ff'}; FooProps props = Foo(existingMap); print(props.color); // #0094ff }
UiProps as a builder
@Factory() UiFactory<FooProps> Foo; @Props() class FooProps extends UiProps { String color; } @Component() class FooComponent extends UiComponent<FooProps> { ReactElement bar() { // Create a UiProps instance to serve as a builder FooProps builder = Foo(); // Add props builder.id = 'the_best_foo'; builder.color = '#ee2724'; // Invoke as a function with the desired children // to return a new instance of the component. return builder('child1', 'child2'); } /// Even better... do it inline! (a.k.a fluent) ReactElement baz() { return (Foo() ..id = 'the_best_foo' ..color = 'red' )( 'child1', 'child2' ); } }
See fluent-style component consumption for more examples on builder usage.
UiState
UiState is a Map class (just like
UiProps) that adds statically-typed getters and setters
for each React component state property.
@State() class FooState extends UiState { // ... }
UiState is optional, and won’t be used for every component.
UiComponent
UiComponent is a subclass of
react.Component, containing lifecycle methods
and rendering logic for components.
@Component() class FooComponent extends UiComponent<FooProps> { // ... }
This component provides statically-typed props via
UiProps, as well as utilities for prop forwarding and CSS class merging.
The
UiStatefulComponentflavor augments
UiComponentbehavior with statically-typed state via
UiState.
Accessing and manipulating props / state within UiComponent
Within the
UiComponentclass,
propsand
stateare not just
Maps. They are instances of
UiPropsand
UiState, which means you don’t need String keys to access them!
newProps()and
newState()are also exposed to conveniently create empty instances of
UiPropsand
UiStateas needed.
typedPropsFactory()and
typedStateFactory()are also exposed to conveniently create typed
props/
stateobjects out of any provided backing map.
@Component() class FooComponent extends UiStatefulComponent<FooProps, FooState> { @override getDefaultProps() => (newProps() ..color = '#66cc00' ); @override getInitialState() => (newState() ..isActive = false ); @override componentWillUpdate(Map newProps, Map newState) { var tNewState = typedStateFactory(newState); var tNewProps = typedPropsFactory(newProps); var becameActive = !state.isActive && tNewState.isActive; // Do something here! } @override render() { return (Dom.div() ..style = { 'color': props.color, 'fontWeight': state.isActive ? 'bold' : 'normal' } )( (Dom.button()..onClick = _handleButtonClick)('Toggle'), props.children ); } void _handleButtonClick(SyntheticMouseEvent event) { _toggleActive(); } void _toggleActive() { setState(newState() ..isActive = !state.isActive ); } }
Fluent-style component consumption
In OverReact, components are consumed by invoking a
UiFactory to return a new
UiProps builder, which is then
modified and invoked to build a
ReactElement.
This is done to make "fluent-style" component consumption possible, so that
the OverReact consumer experience is very similar to the React JS / "vanilla"
react-dart
experience.
To demonstrate the similarities, the example below shows a render method for JS, JSX, react-dart, and over_react that will have the exact same HTML markup result.
- React JS:
render() { return React.createElement('div', {className: 'container'}, React.createElement('h1', null, 'Click the button!'), React.createElement('button', { id: 'main_button', onClick: _handleClick }, 'Click me') ); }
- React JS (JSX):
render() { return <div className="container"> <h1>Click the button!</h1> <button id="main_button" onClick={_handleClick} >Click me</button> </div>; }
- Vanilla react-dart:
render() { return react.div({'className': 'container'}, react.h1({}, 'Click the button!'), react.button({ 'id': 'main_button', 'onClick': _handleClick }, 'Click me') ); }
- OverReact:
render() { return (Dom.div()..className = 'container')( Dom.h1()('Click the button!'), (Dom.button() ..id = 'main_button' ..onClick = _handleClick )('Click me') ); }
Let’s break down the OverReact fluent-style shown above
render() { // Create a builder for a <div>, // add a CSS class name by cascading a typed setter, // and invoke the builder with the HTML DOM <h1> and <button> children. return (Dom.div()..className = 'container')( // Create a builder for an <h1> and invoke it with children. // No need for wrapping parentheses, since no props are added. Dom.h1()('Click the button!'), // Create a builder for a <button>, (Dom.button() // add a ubiquitous DOM prop exposed on all components, // which Dom.button() forwards to its rendered DOM, ..id = 'main_button' // add another prop, ..onClick = _handleClick // and finally invoke the builder with children. )('Click me') ); }
DOM components and props
All react-dart DOM components (
react.div,
react.a, etc.) have a
corresponding
Dom method (
Dom.div(),
Dom.a(), etc.) in OverReact.
ReactElement renderLink() { return (Dom.a() ..id = 'home_link' ..href = '/home' )('Home'); } ReactElement renderResizeHandle() { return (Dom.div() ..className = 'resize-handle' ..onMouseDown = _startDrag )(); }
OverReact DOM components return a new
DomPropsbuilder, which can be used to render them via our fluent interface as shown in the examples above.
DomPropshas statically-typed getters and setters for all "ubiquitous" HTML attribute props.
The
domProps()function is also available to create a new typed Map or a typed view into an existing Map. Useful for manipulating DOM props and adding DOM props to components that don’t forward them directly.
Building custom components
Now that we’ve gone over how to use the
over_react package in your project,
the anatomy of a component and the DOM components
that you get for free from OverReact, you're ready to start building your own custom React UI components.
- Start with one of the component boilerplate templates below.
- Component (props only)
- Stateful Component (props + state)
- Fill in your props and rendering/lifecycle logic.
- Consume your component with the fluent interface.
Run the app you’ve set up to consume
over_react
$ pub serve
That’s it! Code will be automatically generated on the fly by Pub!
component demosto get a feel for what’s possible!
Component Boilerplate Templates
Component Boilerplate
import 'dart:html'; import 'package:react/react.dart' as react; import 'package:react/react_dom.dart' as react_dom; import 'package:react/react_client.dart'; import 'package:over_react/over_react.dart'; @Factory() UiFactory<FooProps> Foo; @Props() class FooProps extends UiProps { // Props go here, declared as fields: bool isDisabled; Iterable<String> items; } @Component() class FooComponent extends UiComponent<FooProps> { @override Map getDefaultProps() => (newProps() // Cascade default props here ..isDisabled = false ..items = [] ); @override render() { // Return the rendered component contents here. // The `props` variable is typed; no need for string keys! } }
Stateful Component Boilerplate
import 'dart:html'; import 'package:react/react.dart' as react; import 'package:react/react_dom.dart' as react_dom; import 'package:react/react_client.dart'; import 'package:over_react/over_react.dart'; @Factory() UiFactory<BarProps> Bar; @Props() class BarProps extends UiProps { // Props go here, declared as fields: bool isDisabled; Iterable<String> items; } @State() class BarState extends UiState { // State goes here, declared as fields: bool isShown; } @Component() class BarComponent extends UiStatefulComponent<BarProps, BarState> { @override Map getDefaultProps() => (newProps() // Cascade default props here ..isDisabled = false ..items = [] ); @override Map getInitialState() => (newState() // Cascade initial state here ..isShown = true ); @override render() { // Return the rendered component contents here. // The `props` variable is typed; no need for string keys! } }
Common Pitfalls
Below you’ll find some common errors / issues that new consumers run into when building custom components.
Don’t see the issue you're having? Tell us about it.
null object does not have a method 'call'
ⓧ Exception: The null object does not have a method 'call'.
This error is thrown when you call a
@Factory() function that has not been initialized due to
the
over_react
transformer not running, you’ll get this error.
Make sure you’ve followed the setup instructions.
404 on
.dart file
ⓧ GET ⓧ An error occurred loading file:
When the
over_react
transformer finds something wrong with your file, it logs an error in Pub and causes the
invalid file to 404. This ensures that when the transformer breaks,
pub build will break, and you’ll know about it.
Check your
pub serve output for errors.
Libraries
- over_react
Base classes for UI components and related utilities.
- over_react.component_base
-
- over_react.transformer
- | https://www.dartdocs.org/documentation/over_react/1.0.2/index.html | CC-MAIN-2017-30 | en | refinedweb |
#include <openvrml/frustum.h>
A frustum is more or less a truncated pyramid. This class represents frustums with their wide end facing down the -z axis, and their (theoretical) tip at the origin. A frustum is a convenient representation of the volume of virtual space visible through the on-screen window when using a perspective projection.
openvrml::child_node::render_child
openvrml::geometry_node::render_geometry
Construct and initialize a frustum.
The field of view should be less than 180 degrees. Extreme aspect ratios are unlikely to work well. The near and far plane distances are always positive (think distance, not position). anear must be less than afar. This is supposed to look like gluPerspective.
Update the plane equations.
The plane equations are derived from the other members.
Vertical field of view.
Horizontal field of view.
Distance to the near clipping plane.
Distance to the far clipping plane.
Left (looking down -z) side clip plane.
Format is (a,b,c,d) where (a,b,c) is the plane normal and d is the plane offset. For the momement the eyepoint is always the origin, so d is going to be 0.
Right clipping plane.
Top clipping plane.
Bottom clipping plane. | http://openvrml.org/doc/classopenvrml_1_1frustum.html | CC-MAIN-2017-30 | en | refinedweb |
In my last post I cracked open the Logging Application Block to extend the Text Formatter so it could log timestamps in either local or UTC time. Since I already had my hands dirty, I thought I'd have a go at another useful extension that we unfortunately didn't get time to include in Enterprise Library for .NET 2.0.
One interesting (but often overlooked) feature of this block is that you can extend the
LogEntry class to include additional properties that make sense for certain types of events. For example, you can subclass
LogEntry into classes like
DataLayerLogEntry, BusinessLayerLogEntry and
AuditLogEntry, each with different strongly-typed properties that you want to collect when different things happen, such as reporting the database server name and stored procedure name in every event raised from your data access layer.
Unfortunately, just building these new
LogEntry classes isn't enough. This is because the TextFormatter and the various TraceListeners don't know anything about these new properties that you've added. One solution would be to modify the TraceListener classes to deal with your new types and properties, but given how many TraceListeners we have, it's not a very attractive solution. Instead, I built a new Token class that works with the existing TextFormatter class that uses reflection so it can deal with any new property in any derived or modified
LogEntry.
Before I get into the solution, let me explain the goals by way of an example. Suppose I built a new LogEntry-derived class like this:
public class DataLayerLogEntry : LogEntry
{
private string databaseServer;
private string command;
// Add as many (or as few) constructors as you want!
public DataLayerLogEntry() : base()
{
}
public string DatabaseServer
{
get { return databaseServer; }
set { databaseServer = value; }
}
public string Command
{
get { return command; }
set { command = value; }
}
}
Now I can easily raise new events of this class from my code, like this (of course you wouldn't hard-code the values in real life, but you get my drift...):
DataLayerLogEntry logEntry = new DataLayerLogEntry();
logEntry.EventId = 123;
logEntry.Message = "Something happened in the data layer";
logEntry.Categories.Add("Data");
logEntry.DatabaseServer = "TOMHOLL1\\SQLEXPRESS";
logEntry.Command = "spDoStuff";
Logger.Write(logEntry);
So far so good, but if I sent this to any TraceListener via the out-of-the-box
TextFormatter, I could get my custom properties out of it. However it's really easy to solve this generically. Again, I chose to just modify the original EntLib solution file, although you could probably separate the code into your own assembly if you're a purist and don't mind working out which code you need to copy or subclass. Also to do it properly you'd probably want to externalize some of the strings to make it localizable. But anyway, here's my new class
ReflectedPropertyToken:
publicclass ReflectedPropertyToken : TokenFunction
{
/// <summary>
/// Constructor that initializes the token with the token name
/// </summary>
public ReflectedPropertyToken() : base("{property(")
{
}
/// <summary>
/// Searches for the reflected property and returns its value as a string
/// </summary>
public override string FormatToken(string tokenTemplate, LogEntry log)
{
// find the property with this name on the log entry
Type logType = log.GetType();
PropertyInfo property = logType.GetProperty(tokenTemplate);
if (property != null)
{
return property.GetValue(log, null).ToString();
}
else
{
return String.Format("<Error: property {0} not found>", tokenTemplate);
}
}
}
The only other thing I needed to do is modify
TextFormatter.RegisterTokenFunctions to tell it about my new token. This just involved adding one more line to the end:
tokenFunctions.Add(new ReflectedPropertyToken());
So how does it work? Using this new token function, you can add the {property(propertyname)} token into your templates. To continue my example, I modified my TextFormatter template to include this:
Message: {message}
Database Server: {property(DatabaseServer)}
Database Command: {property(Command)}
And the result, of course, looks like this:
Message: Something happened in the data layer
Database Server: TOMHOLL1\SQLEXPRESS
Database Command: spDoStuff
The cool thing about this is that it's now easy to use any custom log schemas with (practically) any TraceListener. Also, while I only tested this with the new January 2006 .NET 2.0 version, it should be possible to use very much the same solution with the .NET 1.1 releases of the block too. I hope you find it useful for your applications!This posting is provided "AS IS" with no warranties, and confers no rights.
I tried something similar to this a while ago, but I wanted to use the MSMQ TraceListener (or distributor strategy as it was in those days) and ran into problems with the serialisation/deserialisation. In the end I just put everything into ExtendedProperties.
Really helpful, would like to know more about Custom block, trying to wrok on Custom Block.
This is very nice. I have been trying to find a way to expose the application context so I can get things like server, query string, and form variables as well as what was in the session and cache when an error is logged. I use ELMAH now and I really can’t go back to not having the application context, we have found that having that information at the time of the error is very valuable. Would writing a custom log entry be the best approach or is there another way of getting the application context information I am wanting inside of enterprise library?
A post by Tom Hollander a while back described how to make a Reflected Property formatter so you could | https://blogs.msdn.microsoft.com/tomholl/2006/01/28/a-reflected-property-formatter-token-for-the-logging-application-block/ | CC-MAIN-2017-30 | en | refinedweb |
The search aspect of Ditto can be accessed via an HTTP API.
The concepts of the RQL expression, RQL sorting and
RQL paging are mapped to HTTP as query parameters which are added to
GET requests
to the search endpoint:<1|2>/search/things
If the
filter parameter is omitted, the result contains all
Things the authenticated user is
allowed to read.
Optionally a
namespaces parameter can be added to search only in the given namespaces.
Query parameters
In order to define for which
Things to search, the
filter query parameter has to be added.
In order to change the sorting and limit the result (also to do paging), the
options parameter has to be added.
Complex example:
GET .../search/things?filter=eq(attributes/location,"living-room")&option=sort(+thingId),limit(0,5)&namespaces=org .eclipse.ditto,foo.bar
Another Complex example with the
namespaces parameter:
GET .../search/things?filter=eq(attributes/location,"living-room")&namespaces=org.eclipse.ditto,foo.bar
The HTTP search API can also profit from the partial request concept of the API:
additionally to a
filter and
options, a
fields paramter may be specified in order to select which data of the result
set to retrieve.
Example which only returns
thingId and the
manufacturer attribute of the found Things:
GET .../search/things?filter=eq(attributes/location,"living-room")&fields=thingId,attributes/manufacturer
With the
namespaces parameter, the result can be limited to the given namespaces.
Example which only returns Things with the given namespaces prefix:
GET .../search/things?namespaces=org.eclipse.ditto,foo.bar
Search count
Search counts can be made against this endpoint:<1|2>/search/things/count
Complex example:
GET .../search/things/count?filter=eq(attributes/location,"living-room") | https://www.eclipse.org/ditto/httpapi-search.html | CC-MAIN-2020-05 | en | refinedweb |
Parameters of web controllers that make up the application are what the developers of these applications want to validate. This is how external clients are able to get data into the application. Through the parameters of the controllers. It is thus important to ensure that this data is acceptable to the application.
With FormEncode, schemas may be defined by a controller. These schemas are defined on a per controller basis and include the parameters used by the controller. By using this method of parameter validation, each parameter of the controller can be validated at the same time instead of trying to validate each parameter individually.
However, with schemas that have many parameters to validate, more than one parameter may be at fault for the validation failure. In this case, the exception raised by the validation failure has no useful meaning as a whole. What the client needs is an explanation for why each individual field failed. An example of how this can be done is shown below.
#Example; Better formencode error handling.
import formencode
#A simple validation schema.
class Schema(formencode.Schema):
name=formencode.validators.String(not_empty=True)
#Get meaningful data from the formencode exception.
def format_error(e):
return e.error_dict
#Main.
if __name__=="__main__":
#Attempt to validate.
try:
Schema().to_python({"name":""})
except formencode.Invalid, e:
#Display the better error data.
print format_error(e) | http://www.boduch.ca/2009/10/form-encode-errors.html | CC-MAIN-2020-05 | en | refinedweb |
Getting Started
This guide provides step-by-step instructions on how to create a functional web test with TestCafe and consists of the following sections.
- Installing TestCafe
- Creating a Test
- Running the Test
- Viewing the Test Results
- Writing Test Code
Installing TestCafe #
Ensure that Node.js and npm are installed on your computer and run the following command:
npm install -g testcafe
For more information, see Installing TestCafe.
Creating a Test #
TestCafe allows you to write tests using TypeScript or JavaScript (with its modern features like
async/await).
You get all the advantages of strongly-typed languages like rich coding assistance, painless scalability, check-as-you-type code verification, etc., by using TypeScript to write your TestCafe tests. For more information about writing tests in TypeScript, see TypeScript Support.
To create a test, create a new .js or .ts file. This file must have a special structure - tests must be organized into fixtures.
Firstly, import the
testcafe module.
import { Selector } from 'testcafe';
Then declare a fixture using the fixture function.
fixture `Getting Started`
In this tutorial, you create a test for the sample page. Specify this page as a start page for the fixture using the page function.
fixture `Getting Started` .page ``;
Then, create the test function where you can enter test code.
import { Selector } from 'testcafe'; fixture `Getting Started` .page ``; test('My first test', async t => { // Test code });
Running the Test #
You can run the test from a command shell by calling a single command where you specify the target browser and file path.
testcafe chrome test1.js
TestCafe automatically opens the chosen browser and starts test execution within it..
Viewing the Test Results #
While the test is running, TestCafe is gathering information about the test run and outputting the report in a command shell.
See Reporters for more information.
Writing Test Code #
Performing Actions on the Page #.
import { Selector } from 'testcafe'; fixture `Getting Started` .page ``; test('My first test', async t => { await t .typeText('#developer-name', 'John Smith') .click('#submit-button'); });
All test actions are implemented as async functions of the test controller object
t.
This object is used to access test run API.
To wait for actions to complete, use the
await keyword when calling these actions or action chains.
Observing Page State # their state.
For example, clicking the Submit button on the sample web page opens a "Thank you" page.
To get access to DOM elements on the opened page, the
Selector function can be used.
The following example demonstrates how to access the article header element and obtain its actual text.
import { Selector } from 'testcafe'; fixture `Getting Started` .page ``; test('My first test', async t => { await t .typeText('#developer-name', 'John Smith') .click('#submit-button'); const articleHeader = await Selector('.result-content').find('h1'); // Obtain the text of the article header let headerText = await articleHeader.innerText; });
See Selecting Page Elements for more information.
Assertions #
A functional test should also check the result of actions performed. For example, the article header on the "Thank you" page should address a user using the entered name. To check if the header is correct, you have to add an assertion to the test.
The following test demonstrates how to use built-in assertions.!'); }); | https://devexpress.github.io/testcafe/documentation/getting-started/ | CC-MAIN-2020-05 | en | refinedweb |
NEW: Learning electronics? Ask your questions on the new Electronics Questions & Answers site hosted by CircuitLab.
Microcontroller Programming » AVR Programming without bootloader
I'm looking for a programmer for AVR chips which will allow me to program without the need for a bootloader.
Minimum requirements:-
Simplicity - ZIF socket or similar,
USB connectivity and possibly powered by USB as well,
Compatible with as many different AVR chips as possible,
Compatible with AVR Dude or AVR Studio,(Probably other requirements that elude me at this moment)
What programmer would you suggest?
I wouldn't get a "programmer that is prebuilt with a ZIF Socket".
I would just use one of the many AVR ISP Programmers and then build a small board with a ZIF Socket that you attach the AVR ISP Programmer to to program your chip.
(ISP, stands for "In System Programmer". Atmel has created a hardware/software solution that I believe ALL AVR Microcontrollers support quite literally by definition.)
I use the Atmel ATAVRISP2.
You can get it from numerous sources. (Mouser.com, Digitkey.com, etc...)
There are other ISP Programmers that work as well.
(In fact there are posts here on how to make your own!)
For Atmel Programmer details look here:
AVRISP
For the AVR ISP to work you need a Microcontroller that is in a hardware environment it will run in. (Hence the need for a little board to be made!)
For that I use:
ATmegaXX8
I built the first little board for this mostly identical to the Nerdkits Circuit.
On the top right is the standard header for the AVR ISP.
NOTE: as well that the crystal I use is in a Female Header so that I can change that when I want.
Here's a couple of resources for you -
Nerdkit bootloader installation is about putting the bootloader on new chips but has some good info on ISP programmers. Rick is a great resource on ISP programmers.
Nerdkit ISP Programmer will show you how to make an ISP programmer from your Nerdkit.
I've never bought a programmer but have made several variations of the ISP programmer using my Nerdkit and most recently a version on the Arduino Nano.
Thanks for all the replies.
I was hoping for an 'all-in-one' solution similar to the STK500 so I didn't have to have multiple boards for multiple chips.
As I can see, most of the chips I'll be using will be 'Tinys', but occassionally there'll be the need for a 'Mega'.
Does anyone have any experience / reviews on the STK500 or similar?
Any isp programmer can program all the ATmegas.
As well as the ATtiny's.
"As well as the ATtiny's."
Except for a very few such as the ATtiny10. That series uses a different protocol. I don't see a lot of those in use though.
Which tinys were you wanting to program, TuffLux?
I had purchased the Atmel STK500 and another AVR Programming Solution similar to what envision. (Ever so long ago now.)
Both were Serially Connected solutions.
I was VERY disappointed in both.
(If I remember correctly for the STK500 there were onboard jumpers that were not clearly marked, at least to me, that had to be changed for different chips that was the root of my disappointment...)
There still are some Professional Programmers that do what you are asking, but most decent ones are quite expensive.
How many different AVR Chips do you think you will need to use?
I have 1 board I use to program, and a backup board, and every project I have has the ISP Connector on at least the first project board. (Adding an ISP Connector is simply adding 1 6-pin dual-inline header to the working project board.)
For my main board I use to program the AVR's I also have some adapter boards I made so that I can just plug-in bigger and smaller AVR's into the same board to program.
Peoples needs, and things that make them happy are different. I don't really espouse for a one-size-fits-all theory in anything.
For me though using the Atmel ISP Programming Interface with a designated target board or my current project board is what I prefer, no matter what ISP Programmer I am using.
If you are looking at other programmers I would be very cautious of getting a STK600 (Atmel's latest replacement to the STK500).
You can "potentially" program everything from Atmel but they tend to only last 3 months.
I have close to a thousand dollars invested in my STK600 and it is dead.
I really like my Atmel Dragon it also does high voltage parrallel programing which I use often.
Ralph
Currently I'm looking at programming the Tiny4's. They have just enough pins for what I want and are very power efficient. The only problem I have is that I'll have to program them using HVSP. So that eliminates ISP programmers.
I do see the Tiny5 has an ADC which could become useful, if only I could find a supplier of those...
That is interesting, those little mcu's were not even on my radar. Just for fun I'll have to get a few of the Tiny10's so I can modify the isp programmer to program them too.
Noter :-
Would be interesting to see.
I'm pretty sure you can't use an ISP programmer to switch all four pins to I/O though. I think you need to use a HV programmer.
I would just use the isp programmer as a base because it has all the logic to play with avrdude already in it. The task is to change the interface wiring and command set to be compatible with the Tiny4-5-8-10's and then call it a HVSP programmer. I made a HV programmer for the ATmega44-88-168-328's that I developed in the same fashion so I'm pretty confident it will work. I've already added tiny10's to my pending mouser order and will probably place it next week.
This Blog was where I got my 1st exposure to those little critters. I haven't really played with them though, just knew they were around. They might be great for simple 1 or two channel PWM or ADC work of some sort.
Rick
Got my ATtiny10's this week and they are really tiny! It was difficult to get it soldered onto the adapter because it was almost impossible to hold down and solder at the same time. Just looking at it made it move!
So now it's on to the fun part, making a TPI programmer and then getting the tiny10 to blink a few leds. I'm using the same nerdkit setup as the AVR_ISP programmer but not messing with the bootloader this time around, just loading direct with my ISP programmer. Then I can test the TPI programmer using the nerdkit usb cable connected directly to the ATmega328 on the breadboard.
Those little buggers are cute, but I don't know if I'd ever have a use for them. I can see what you mean about breathing on them making them move! What are your intended uses for them??
I don't have a specific use for them yet beyond just learning. I can see where they might be useful for pwm control of brightness and contrast on a LCD or something like that. But they have no built-in eeprom so keeping a setting can't be done without external help. Next time I order from Mouser I think I'll get a couple of these tiny 128 byte eeproms to try out -
Just looking at it made it move!
Just looking at it made it move!
I use a drop of Super Glue to hold them while soldering.
The heat of soldering will sometimes break the bond but it usually holds long enough to get everything soldered.
Thanks Ralph. I'll give that a try next time.
Paul
Here's a little program that will fit on the ATtiny10. Doesn't do much, just randomly blinks a LED to sort of simulate a candle. Main thing now is just to get something that fits because the ATtiny10 only has 1k byte of flash.
// LED-Candle.c
// Single LED Candle Simulation
/*
Use the following compile/link command to produce the 686>
ISR(TIMER0_COMPA_vect, ISR_BLOCK) {
PORTC &= ~(1<<PC2); // turn off
}
ISR(TIMER0_OVF_vect, ISR_BLOCK) {
PORTC |= (1<<PC2); // turn on
}
/**********************************************************************/
int main() {
// set pin for output
DDRC |= (1<<PC2);
// start the timer
TIMSK0 |= _BV(OCIE0A) | _BV(TOV0);
TCCR0B = _BV(CS00);
// enable interrupts
sei();
while(1){
OCR0A = (rand()&127)+128;
_delay_ms(100);
}
}
Got it down to 640 bytes by switching to timer2 and PB3 so that fast PWM does all the work.
// LED-Candle.c
// Single LED Candle Simulation
/*
Use the following compile/link command to produce the 640>
/**********************************************************************/
int main() {
// set pin for output
DDRB |= (1<<PB3);
// start the timer
TCCR2A = _BV(COM2A1) | _BV(WGM21) | _BV(WGM20);
TCCR2B = _BV(CS20);
while(1){
OCR2A = (rand()&127)+128;
_delay_ms(100);
}
}
With only 1K of flash, I would have thought assembly would have been the way to go. Good job getting the C to compile down that small. Is it the rand function eating up the bulk of the space? Do I remember correctly that the underscore before a function call forces a jump to a single occurrence of the code in the binary? Anyway, pretty cool to see you have the little micro running. Of course, I never doubted you would.
Rick
Hi Rick,
I don't actually have it on the ATtiny10 yet. Wanted to get it working on the Nerdkit first so I know the code is good when I do get it loaded onto the ATtiny. Sorry to mislead.
Yep, the rand() is the bulk of the code. Without it the size is 166 bytes so the rand() is 474 of the 640 bytes used.
Assembly is probably the best way to go but I am very rusty on assemblers and also have not written a program for the AVR in assembly yet so the easy out for me is to write it in C. The tiny chip has only 32 bytes of SRAM and probably that is the real limiting factor for doing anything very complicated anyway.
I am not familiar with using an underscore before a function call and I couldn't find anything on it in the documentation. Must have been another language/platform.
Got the new TPI programmer working and now have my candle emulator running on the ATtiny10. Couldn't use the lib version of rand() but fortunately found suitable code on the web that only uses about 1/2 the flash anyway. This version of the test program occupies only 238 bytes of flash.
// LED-Candle.c
// Dual LED Candle Simulator
// output PWM on OC?A
// timer0 on ATtiny - OC0A, OC0B - PB0, PB1
#include <avr/interrupt.h>
#include <util/delay.h>
/**********************************************************************/
int main() {
// bump clock to 8MHz
CCP = 0xD8;
CLKPSR = 0;
DDRB |= _BV(PB0); // set OC0A output
DDRB |= _BV(PB1); // set OC0B output
// start the timer
OCR0A = 3;
OCR0B = 3;
TCCR0A = _BV(COM0A1) | _BV(COM0B1) | _BV(WGM00);
TCCR0B = _BV(CS00) | _BV(WGM02);
// ref
#define RAND_MAX_32 ((1UL << 31) - 1)
uint32_t rseed = 0;
while(1){
rseed = ((rseed * 214013UL + 2531011UL) & RAND_MAX_32) >> 16;
OCR0B = OCR0A;
OCR0A = (rseed%128)|128|3;
_delay_ms(100);
}
}
Perfect time of year to build a fake candle. Justify the hobby to the wife as "I'm designing Christmas decorations... "
Good going on the programmer modifications. I'm going to have to mess with that one day. I've often thought the ATMEGA32U4 (Like the TEENSY) based boards would make a good programmer since they have built in USB support, but have never tried it. Ahh... a project for another day.
Thanks for the update,
My wife likes the fake candle. It makes a great night light too. I taped a piece of decorative paper together to make a cylinder and just set it over the leds. Looks almost real. It looks brighter in the photo than it really is.
I had the same thought on using the built-in USB and bought a couple of 32U4s a several weeks ago with a Mouser order. Then I laid out a TQFP-44 adapter and ordered a few from OshPark and now have one put together ready to go. Updated lcd code to use different pins and it is working in a little test program so now I can get busy on the USB. I think I'll start with the LUFA libraries and see how that goes.
I got my tpi programmer working on the ATmega32U4 using the LUFA library. But it's a big chip with 44 pins so I switched over to the AT90USB162 and it's definitely a better fit for the TPI programmer. I found a SOT-23 socket on eBay that will work well for the ATtiny10 so now all I have to do is design a PCB to get it off the breadboard and make it a permanent fixture in my bag of tricks. Maybe in a month it will be completely done.
Looks real good, what's the little 8 pin IC in between the AT90USB162 and the ATTINY10?
It's a max662 and puts out 12v to enable HV programming on the tiny10. It's all powered from the USB 5v so needed something to get 12v. The thick red and black wires go to my multi-meter.
Please log in to post a reply. | http://www.nerdkits.com/forum/thread/2518/ | CC-MAIN-2020-05 | en | refinedweb |
Data Points
The Enterprise Library Data Access Application Block, Part 3
John Papa
Code download available at:DataPoints0510.exe(216 KB)
Contents
Saving Data via SQL
Stored Procedures and One-Liners
Wrap a Transaction
Save a Row via UpdateDataSet
Save Multiple Rows at Once
Test as You Go
Wrapping It Up. Fortunately, the Enterprise Library Data Access Application Block (DAAB), which I covered in my past two columns, exposes several ways to commit data changes to a database provider using ADO.NET (see The Enterprise Library Data Access Application Block, Part 1 and The Enterprise Library Data Access Application Block, Part 2).
This month, I will demonstrate several ways the Enterprise Library DAAB can modify data, how you can implement transactions with it, and how to set up NUnit to test the data access code.
I will start by building upon and modifying the Windows® Forms project from the August issue so that all data retrieval and modification are performed within the same project. (All of the code samples for the project I will discuss in this column can be downloaded from the MSDN® Magazine Web site.)
Saving Data via SQL
In the August Data Points column, I explained how to set up a project to refer to and use the DAAB. So, you should be ready to start saving data. The DAAB exposes several methods to retrieve and save data and they all have different purposes (see Figure 1). This month I'll focus on ExecuteNonQuery and UpdateDataSet.
Figure 1 DAAB Get and Save Methods
My first example shows how to pass a SQL statement to the DAAB to execute and save data to the database. After creating an instance of the DAAB Database class, I create an instance of a DBCommandWrapper class by passing the SQL statement to the GetSqlStringCommandWrapper method of the Database object.
I use the AddInParameter method of the DBCommandWrapper to set the values of the parameters that I used in the UPDATE SQL statement. I could have used the AddParameter method as well, which allows a little more flexibility since you can specify the direction. However, in this case the AddInParameter was sufficient as it wraps the basic settings I wanted for the input parameters. Executing the command is as easy as invoking the ExecuteNonQuery method of the Database object and passing to it the instance of the DBCommandWrapper. Finally, I query the database to get the customer record so I can return it to the form so the user can see that the changes took effect. This code is quite simple to execute and properly uses parameters to help alleviate the risk of a SQL injection attack.
Stored Procedures and One-Liners
The customer data could be updated using a stored procedure just as easily. The code in Figure 2 could be modified slightly to accept a stored procedure name instead of the SQL statement. For example, by replacing the SQL statement with the name of the stored procedure and creating the DBCommandWrapper by invoking the GetStoredProcCommandWrapper method of the Database object, the code will now execute a stored procedure:
string proc = "prUpdateCustomer"; DBCommandWrapper cmd = db.GetStoredProcCommandWrapper(proc);
Figure 2 Updating Data with ExecuteNonQuery
public string SaveCustomersViaSql(string customerID, string companyName, string city, string country) { string sql = "UPDATE Customers SET CompanyName = @companyName, " + "City = @city, Country = @country WHERE CustomerID = @customerID"; Database db = DatabaseFactory.CreateDatabase(); DBCommandWrapper cmd = db.GetSqlStringCommandWrapper(sql); cmd.AddInParameter("companyName", DbType.String, companyName); cmd.AddInParameter("city", DbType.String, city); cmd.AddInParameter("country", DbType.String, country); cmd.AddInParameter("customerID", DbType.String, customerID); db.ExecuteNonQuery(cmd); return GetCustomerViaOutputParameters(customerID); }
If you want to try these two techniques, you can run them through the Windows Forms project (shown in Figure 3) by executing list items 8 and 9. List item 10 in the Windows Forms also executes a stored procedure to update a customer. However, the difference with this technique is that it executes the stored procedure using a single line of code. Notice that the following method executes the stored procedure in the first line of code and then gets the modified row again to display to the user (which you could choose to omit):
public string SaveCustomersViaStoredProcedureWithoutDBCommandWrapper( string customerID, string companyName, string city, string country) { DatabaseFactory.CreateDatabase().ExecuteNonQuery( "prUpdateCustomer", customerID, companyName, city, country); return GetCustomerViaOutputParameters(customerID); }
This line of code creates an instance of the Database object and invokes its ExecuteNonQuery method. One of the overloaded signatures for the ExecuteNonQuery method accepts the name of a stored procedure and a parameter array of parameter values for the stored procedure. Of course, the list of parameter values must match the data types and the number of parameters that the stored procedure accepts. Otherwise, an exception will be raised.
Figure 3** The Project **
The DAAB handles parameters nicely in this situation. When a stored procedure is executed by name and its parameters are passed to the ExecuteNonQuery through the parameter array, the DAAB asks the database for the list of parameters and figures this out for you. In the past this sort of operation has been very costly since every call to a stored procedure meant a costly search and discovery of the parameters in addition to the call to execute the stored procedure. The DAAB alleviates some of this concern by introducing parameter caching so that subsequent calls use the cached parameter information instead of hitting up the database to discover the parameters again.
Wrap a Transaction
Most enterprise applications at one time or another need to use transactions to wrap multiple action queries in an atomic unit of work. The DAAB wraps the transactional features of ADO.NET and exposes them so they can be used with the DAAB.
When using transactions, it is best to keep them open for as short a period of time as possible, performing only the minimal, essential queries inside of the transaction's scope. Any code that can be run outside of the transaction should be. This helps to minimize the lifetime of the locks that are held open during the transaction.
Figure 4 shows a method that accepts a list of regions and a list of territories that it will insert into the database. I create the transaction by first getting the connection object from the Database object's GetConnection method. Once I open the connection, I create an instance of the transaction and begin the transaction by calling the BeginTransaction method of the connection object:
IDbTransaction transaction = connection.BeginTransaction();
Figure 4 Using Transactions
public void InsertRegionsAndTerritoriesInTransaction( ArrayList territories, ArrayList regions) { Database db = DatabaseFactory.CreateDatabase(); IDbConnection connection = db.GetConnection(); connection.Open(); IDbTransaction transaction = connection.BeginTransaction(); try { string insertRegionProc = "prInsertRegion"; foreach(RegionEntity newRegion in regions) { DBCommandWrapper regionCmd = db.GetStoredProcCommandWrapper(insertRegionProc); regionCmd.AddInParameter("id", DbType.Int32, newRegion.ID); regionCmd.AddInParameter("region", DbType.String, newRegion.Description); db.ExecuteNonQuery(regionCmd, transaction); } string insertTerritoryProc = "prInsertTerritory"; foreach(TerritoryEntity newTerritory in territories) { DBCommandWrapper territoryCmd = db.GetStoredProcCommandWrapper(insertTerritoryProc); territoryCmd.AddInParameter("id", DbType.Int32, newTerritory.ID); territoryCmd.AddInParameter("territory", DbType.String, newTerritory.Description); territoryCmd.AddInParameter("regionID", DbType.Int32, newTerritory.RegionID); db.ExecuteNonQuery(territoryCmd, transaction); } transaction.Commit(); } catch { transaction.Rollback(); throw; } finally { if (connection.State == ConnectionState.Open) connection.Close(); } }
Now that I have a valid, open transaction I enclose all of my commands in a try/catch block so I can handle a rollback in the event that something goes wrong. I loop through the ArrayList of region objects that were passed in to this method, using the ExecuteNonQuery method of the Database object to invoke a stored procedure for each. The one key difference here is that I use the overloaded signature for the ExecuteNonQuery method that accepts an IDbTransaction object. When a transaction is passed to this method, the Database object will enlist the DBCommandWrapper object's command in the transaction. In my example I have three regions in the regions list, so the stored procedure is executed three times, all of which are enlisted within a single overarching transaction.
I then loop through an ArrayList of territories to insert into the database. Following the same model that the region code did, I use the ExecuteNonQuery method to execute the stored procedure that inserts the territories within the same transaction. In my example I execute three territories in addition to the three regions. All six stored procedure calls are wrapped inside of the same transaction so they all fail or commit as a single unit of work.
Save a Row via UpdateDataSet
One of the more popular features of ADO.NET is that it allows you to modify a row in a DataSet and use the DataAdapter's Update method to send the changes to the database. The DataAdapter will iterate through the changed rows and determine which command to execute (InsertCommand, UpdateCommand, or DeleteCommand) based upon the rowstate of the row in the DataSet's DataTable. In the next example, I get a DataSet full of customers and I modify a single customer row by changing the CompanyName and the City. I then pass the DataSet to the method shown in Figure 5, which uses the DAAB to save the row to the database.
Figure 5 Save One Row of a DataSet
public void Save1CustomerViaUpdateDataSet(DataSet ds) { Database db = DatabaseFactory.CreateDatabase();); int rowsAffected = db.UpdateDataSet(ds, "Customers", null, updateCmd, null, UpdateBehavior.Standard); }
The code in the method in Figure 5 is quite familiar since I create the Database object, the DBCommandWrapper, and add the parameters. The difference is in how I execute the stored procedure to update the customer row. Instead of invoking the stored procedure through the ExecuteNonQuery method, I use the UpdateDataSet method. The UpdateDataSet method accepts as its first two arguments the DataSet instance and the name of the DataTable that should be examined and updated. The next three arguments represent three DBCommandWrapper objects that are to be used as the INSERT, UPDATE, and DELETE commands, respectively. In this case, I know I am only updating a single row and that it is indeed an UPDATE, so I only pass the updateCommand argument for the DBCommandWrapper and I pass null for the other two command arguments. (In the next example I will show how to use all three command arguments.)
Since there is only a single row updated in this example, the last argument is irrelevant. The UpdateBehavior enumeration allows you to indicate how the DAAB (and ADO.NET) should behave if more than one row is being modified and one of the rows fails. If a row fails and the behavior is Standard (as it is in Figure 5), then an exception will be thrown and the entire batch will fail. If the behavior is ContinueOnError and one of the rows fails, then that row is logged but the commands continue to execute the remaining modified rows to the database. The rows in error can be examined later and displayed to the user or logged if you so desire.
Save Multiple Rows at Once
In the example in Figure 5 I updated a single customer record using the UpdateDataSet method. When the DataSet and the UpdateDataSet method work together, they can update, insert, and delete several rows based on each row's rowstate. The UpdateDataSet method tells the DAAB to iterate through the changed rows in the DataSet's specified DataTable. For example, when it sees that a row has been modified, it executes the update command and when a row has been deleted, it executes the delete command.
The parameters are filled in using the values from the DataSet's DataTable's row values. (That's a mouthful!) So as the DataTable's changed rows are iterated through, each row is examined and the parameters' values are grabbed from the current row. Figure 6 demonstrates how this can be done. The full code (including the code that modifies the rows, adds new rows, deletes some rows in the DataSet, and then calls this method) is included in the code download on the MSDN Magazine Web site.
Figure 6 Saving Multiple Rows at Once via UpdateDataSet
public void SaveCustomersViaUpdateDataSet(DataSet ds) { Database db = DatabaseFactory.CreateDatabase(); string insertProc = "prInsertCustomer"; DBCommandWrapper insertCmd = db.GetStoredProcCommandWrapper(insertProc); insertCmd.AddInParameter("customerID", DbType.String, "CustomerID", DataRowVersion.Current); insertCmd.AddInParameter("companyName", DbType.String, "CompanyName", DataRowVersion.Current); insertCmd.AddInParameter("city", DbType.String, "City", DataRowVersion.Current); insertCmd.AddInParameter("country", DbType.String, "Country", DataRowVersion.Current);); string deleteProc = "prDeleteCustomer"; DBCommandWrapper deleteCmd = db.GetStoredProcCommandWrapper(deleteProc); deleteCmd.AddInParameter("customerID", DbType.String, "CustomerID", DataRowVersion.Current); IDbConnection connection = db.GetConnection(); connection.Open(); IDbTransaction transaction = connection.BeginTransaction(); try { int rowsAffected = db.UpdateDataSet(ds, "Customers", insertCmd, updateCmd, deleteCmd, transaction); transaction.Commit(); } catch { transaction.Rollback(); throw; } finally { if (connection.State == ConnectionState.Open) connection.Close(); } }
Test as You Go
Since the DAAB itself includes the unit tests that were used during the test-driven development (TDD) cycle when the DAAB was developed, I thought it would be interesting to show some examples of how to create your own unit tests. I created basic unit tests for each example method that is found in the included Windows Forms project. (For brevity I did not create extensive unit tests.) For my examples I use the NUnit unit-testing framework, which you can obtain from.
If you look inside of the sample project in the download, you will see a subfolder named Tests. This folder contains the unit tests for the sample project. The unit tests are intended to verify that each method (or unit of work) succeeds under ideal situations and that each fails under expected failure circumstances. There are a few basic steps I used to create these unit tests.
- I named my test class CustomerFixture so that it is easily identifiable, referenced the NUnit.Framework, and imported the relevant NUnit namespaces with using statements.
- I placed the CustomerFixture class file inside of the Tests subfolder and surrounded the test class with a compilation directive so that they only included in specific builds:
#if UNIT_TESTS ... #endif
I added the compilation variable UNIT_TESTS to the project's debug configuration.
I decorated the unit test class with the [TestFixture] attribute (NUnit looks for these attributes) and each test method with the [Test] attribute.
I added the Category attribute to each of my test methods so I could easily organize my units tests. (I choose to create a category for all my Gets and Saves).
I used Assert statements in order to look for both valid and invalid conditions.
I find that it is a good practice to set the data back to its original state if you modify it during a test. This allows you to rerun the tests without having to manually change data. For a good look at unit testing data access layers, see Roy Osherove's article in the June 2005 issue of MSDN Magazine, available at Know Thy Code: Simplify Data Layer Unit Testing using Enterprise Services. If you want to see more examples of TDD beyond what I provided in the sample project included here, you can look at the Enterprise Library blocks.
Wrapping It Up
Over the past three installments of Data Points I have examined several aspects of the Enterprise Library DAAB including why it exists, its value, how to set up your project to use it, how to read and save data with it, and how to implement transactions. Now you're ready to use the Enterprise Library DAAB in data-centric apps.
Send your questions and comments for John to mmdata@microsoft.com.
John Papa is a Senior .NET Consultant with ASPSOFT and a baseball fanatic who spends most of his summer nights rooting for the Yankees with his family and his faithful dog, Kadi. He has authored several books on ADO, XML, and SQL Server, and can often be found speaking at industry conferences such as VSLive or blogging at codebetter.com/blogs/john.papa. | https://docs.microsoft.com/en-us/archive/msdn-magazine/2005/october/the-enterprise-library-data-access-application-block-part-3 | CC-MAIN-2020-05 | en | refinedweb |
;
- Redux: official documentation;
- Ducks: Redux Reducer Bundles;
- Re-ducks: Building on the duck legacy;
- React & Redux TypeScript guide;
The proposed architecture is not meant to be enforced dogmatically and is a work in progress that might change over time.
File structure
Dan Abramov created a guide for organising files and he got a very good point. For months I’ve been following the “good” ways to organise React projects: starting at the separation of concerns with Presentational and Container components, finishing at adapting ducks.
It worked well for small projects, but as they grew to be 30 different, unique screens and over 200 components, it became more difficult to maintain all of this together. At Milo, we came with a directory structure that is inspired by Django and best-practices from React, taking the separation of concerns to its extreme.
src/ ├── App.tsx ├── index.ts ├── store.ts ├── types.ts ├── shared/ │ └── ComponentName.tsx ├── modules/ │ └── <moduleName>/ │ ├── components/ │ │ └── ComponentName.tsx │ ├── actionCreators.ts │ ├── actionTypes.ts │ ├── apiCalls.ts │ ├── operations.ts │ ├── selectors.ts │ ├── reducers.ts │ ├── utils.ts │ ├── types.ts │ └── index.ts └── screens/ ├── <screenNamespace>/ │ ├── SubcreenNameA.tsx │ └── SubcreenNameB.tsx └── Navigation.ts
Shared
This contains the shared code used all across your app. It can include configuration files, primary presentational components (i.e. Buttons, Inputs, Grid, …) helpers to work with the API and pretty much everything that doesn’t fit in other parts of the proposed architecture.
Screens
Screens are components which are directly mounted on routes (
react-router,
react-navigation). They render shared and/or modules’ components.
Modules
Sometimes, we need to share the logic between web (React) and mobile (React Native) apps. The proposed structure makes it very easy to reuse and maintain the code without influencing other app parts.
The main idea of
modules/ is to group together a strongly coupled part of the application and make it as reusable as possible. It contains all the required components (later used in screens) as well as reducers, action creators and other state-related utilities.
- A module must contain the entire logic for handling its concept;
- A module may contain all the required components to present its concept.
Components
We don’t always follow the concept of a container and presentational components – the promoted thing with this concept is the separation of concerns which can be achieved in different, more maintainable ways, for example though the Hooks API. Do what is more suitable for your case.
.” – Dan Abramov
Index
The
index.ts file should expose the public API of a module. Everything that is not exposed in this file should be considered private and never accessed from the outside.
- The default export must be the reducer.
- It must exports
actions,
operations,
selectorsand
types.
- It must expose all the components.
import * as actions from "./actionCreators"; import * as operations from "./operations"; import * as selectors from "./selectors"; import * as types from "./types"; import reducer from "./reducers"; // Store/state related stuff: export default reducer; export { actions, operations, selectors, types }; // Components: export { default as ComponentNameA } from "./components/ComponentNameA"; export { default as ComponentNameB } from "./components/ComponentNameB";
Action Types
Action types are constants used by action creators and reducers. Each action type should be unique, prefixed by the project and module name.
export const POSTS_REQUEST = "@@<project_name>/<module_name>/POSTS_REQUEST"; export const POSTS_PROCESS = "@@<project_name>/<module_name>/POSTS_PROCESS";
Your action types should be pure string literals. Dynamic string operations (like template strings, string concatenation, etc.) will widen literal type to its supertype string. This will break contextual typing in reducer cases when using TypeScript or Flow.
Action Creators
The action creators should follow the Flow Standard Action specification when possible. Action shape should be predictable and known by the developers. Action creators should not contain any logic, nor transform the received payload – it makes them harder to test and the code is harder to debug.
import { createStandardAction } from "typesafe-actions"; import * as Types from "./actionTypes"; import { Payload } from "./types"; export const requestPosts = createStandardAction(Types.POSTS_REQUEST)<void>(); export const processPosts = createStandardAction(Types.POSTS_REQUEST)<Payload | Error>();
You should not export any default value in
actionCreators.ts. Using named exports, it is easier to map dispatch to all actions exposed by a module using
bindActionCreators, as follows:
import { bindActionCreators } from "redux"; import * as Types from "../../types"; import { actions as moduleActionsA } from "../moduleA"; import { actions as moduleActionsB } from "../moduleB"; const mapDispatchToProps = (dispatch: Dispatch<Types.RootAction>) => bindActionCreators({ ...moduleActionsA, ...moduleActionsB }, dispatch);
API Calls
API endpoints should not be hand-coded – it makes the code prone to errors and harder to maintain as API evolves. I encourage you to create a small configuration file with all available endpoints in
config.ts file, then reuse those endpoints in
apiCalls.ts.
Configuration
const URL = ""; const API = ""; export default { v1: { posts: { get(id: number, meta?: Object) { return `${URL}${API}v1/posts/${id}${createQueryString(meta)}`; }, list(meta?: Object) { return `${URL}${API}v1/posts${createQueryString(meta)}`; } } }, v2: { /* ... */ } };
API Calls
export const fetchPost = (id: number, meta: Object) => fetch(urls.v1.posts.get(id, meta)) .then(response => response.json()); export const fetchPosts = (meta: Object) => fetch(urls.v1.posts.list(meta)) .then(response => response.json());
Operations
Operations can be thunks or sagas and everything else that delays the action dispatch. An operation is a function which can contain logic, dispatch multiple actions based on some predicates and manipulate their payload.
import * as Types from "../types"; import * as actions from "./actionCreators"; import * as API from "./apiCalls"; export const doFooStuff = (payload: Object) => (dispatch: Dispatch<Types.RootAction>) => { dispatch(actions.requestPosts()); API.fetchPosts(payload.meta) .then(data => dispatch(actions.processPosts(normalizePosts(data)))) .catch(err => dispatch(actions.processPosts(err, true))); };
Selectors
Selectors can compute derived data, allowing Redux to store the minimal possible state. A selector is not recomputed unless one of its arguments changes. It minimized the amount of component re-renders to the minimum. Have a look at the excellent reselect package.
Consider the following example – it renders a list of posts created by the currently logged-in user:
class PostsList extends React.PureComponent { render() { return ( <ul> { this.props.posts .filter(post => post.author = this.props.userId) .map(post => ( <div> <p>{post.title}</p> <p>{post.content}</p> </div> )) } </ul> ); } } const mapStateToProps = state => ({ posts: state.posts.data, userId: state.auth.user.id });
In the example above, a render is triggered every time the post collection changes, even if the changed post is not created by the user. Using selectors, we can avoid those unnecessary re-renders and update the component only if one of the user’s posts has been created or modified:
// selectors.ts import { createSelector } from "reselect"; const postsSelector = state => state.posts.data; const userSelector = state => state.auth.user; const userPostsSelector = createSelector( postsSelector, userSelector, (posts, user) => posts.filter(post => post.author === user.id) );
// PostsList.tsx class PostsList extends React.PureComponent { render() { return ( <ul> {this.props.userPosts.map(post => ( <div> <p>{post.title}</p> <p>{post.content}</p> </div> ))} </ul> ); } } const mapStateToProps = state => ({ userPosts: userPostsSelector(state) });
The other thing about selectors is that it facilitates the work with a part of the application that was developed by somebody else – you don’t need to know the state’ shape to work with it if the exposed selectors are enough and well documented.
Reducers
You should export one reducer per module, but a module can be composed of multiple reducers. Don’t be afraid to break your reducer into multiple chunks to reduce complexity and make it easier to test. You can always combine them using
combineReducers.
import { combineReducers } from "redux"; import { Action, PostsState, ErrorsState, LoadingState } from "./types"; import * as Types from "./actionTypes"; export const postsReducer = (state: PostsState = {}, action: Action) => { switch (action.type) { case Types.POSTS_PROCESS: if (!action.error) return {...state, action.payload}; default: return state; } } export const errorsReducer = (state: ErrorsState = null, action: Action) => { switch (action.type) { case Types.POSTS_PROCESS: if (action.error) return action.payload; default: return state; } export const loadingReducer = (state: LoadingState = false, action: Action) => { switch (action.type) { case Types.POSTS_REQUEST: return true; case Types.POSTS_PROCESS: return false; default: return state; } } export default combineReducers({ data: postsReducer, errors: errorsReducer, loading: loadingReducer });
Types
If you use Flow or TypeScript, it’s a good idea to keep all the types in one place (
types.ts). By doing so, we can expose all of them at once to other modules of the app. This is particularly handy when we need to expose the root
Action and
State which is used in every selector and container. Here’s an example of
/types.ts:
import { AnyAction } from "redux"; import { StateType } from "typesafe-actions"; import rootReducer from "./reducers"; import { types as FooTypes } from "../../modules/foo"; import { types as BarTypes } from "../../modules/bar"; export type RootState = StateType<typeof rootReducer>; export type RootAction = FooTypes.Action | BarTypes.Action | AnyAction;
Utilities for state management
You can think of Redux as a low-level API – it doesn’t force any particular patterns and allow you pretty much to do whatever you want.
- Ramda: a practical functional library for JavaScript programmers.
- Immer: create the next immutable state by mutating the current one.
Utilities for creating styles
Creating styles can be a pain, especially in React Native or when you need to create custom styles based on the state. Styled Components can come handy – they allow you to create styles directly in JavaScript using SCSS syntax.
Tips and tricks
You can use reducers on inner state
Creating reducers to handle the inner component state is a good practice in the case when you have complex state logic – it is easier to test and in most cases, less error-prone. Creating reducers for inner state management is even easier with the new Hooks API.
Example: from official React
useReducer example:
export const initialState = { count: 0 }; export function reducer(state, action) { switch (action.type) { case "increment": return {count: state.count + 1}; case "decrement": return {count: state.count - 1}; default: throw new Error(); } } export default function Counter({initialState}) { const [state, dispatch] = useReducer(reducer, initialState); return ( <> Count: {state.count} <button onClick={() => dispatch({type: "increment"})}>+</button> <button onClick={() => dispatch({type: "decrement"})}>-</button> </> ); }
Do’s and don’ts
Never render a list of children without assigning a unique key to each
This can have a huge impact on the performance, even bigger if you rendering a big list of elements. As from React documentation:.
Don’t:
class FooComponent extends React.Component { render() { return this.props.data.map(item => <Item data={item} />); } } class FooComponent extends React.Component { render() { return this.props.data.map((item, index) => <Item key={index} data={item} />); } }
Do:
class FooComponent extends React.Component { render() { return this.props.data.map(item => <Item key={item.id} data={item} />); } }
Never create functions or objects in props
This can have a huge impact on the performance. If you create new objects or functions in the props, a new reference will be passed down to the child each time its parents re-render, resulting in unnecessary re-renders and probably more unwanted behaviours.
Don’t:
class FooComponent extends React.Component { render() { return ( <FooChild onClick={() => this.props.handleClick(...args)} data={this.props.filter(item => item.id === 5)} /> ); } }
Do:
class FooComponent extends React.Component { onClick = (...args) => event => { return this.props.handleClick(...args); }; render() { return ( <FooChild onClick={this.onClick(...args)} data={this.props.filteredData} /> ); } }
Avoid duplicating data between props and state
If some data can be derived or calculated directly from the props, it’s unnecessary to replicate this data in state. Props should be the only source of truth. In fact – if you want to calculate the state based on the received props, you’ll need to create a
componentDidUpdate method and keep you state and props in sync – this is an anti-pattern.
The only case when assigning props to state is acceptable is to pass initial data to a component which doesn’t need to be in sync with the store, e.g. forms.
Avoid:
class FooComponent extends React.Component { state = { foo: this.props.foo, bar: this.props.bar, } }
Avoid overusing HOCs
As Michael Jackson (React-Router co-creator) said:
“Next time you think you need a HOC (higher-order component) in, you probably don’t. I can do anything you’re doing with your HOC using a regular component with a render prop.“ – Michael Jackson
Avoid using Components without
shouldComponentUpdate
A
React.Component, when used without
shouldComponentUpdate, will re-render on every prop and state change.
- Consider creating a
shouldComponentUpdate()method to prevent unnecessary re-renders.
- Consider using the built-in
PureComponentinstead of writing
shouldComponentUpdateby hand.
PureComponentperforms a shallow comparison of props and state, and reduces the chance that you’ll skip a necessary update. | https://laniewski.me/javascript/react/redux/2019/02/28/enterprise-scale-react-redux-project-architecture.html | CC-MAIN-2020-05 | en | refinedweb |
This article is a practical overview of Object Oriented Programming (OOP) in Python. It explains why OOP is useful, aside from how it’s done. This should be useful to both people who don’t know what OOP is, and experienced developers transitioning from other languages.
I am not a professional Python developer, and I am currently re-learning the language after not having used it for 8 years. So keep that in mind as you read, and feel free to offer feedback that can improve the quality of this article. Just be nice. 🙂
Due to the eternal divide between Python 2 and 3, I have to state that I’m using Python 3.6.4 here. Why Python 3? Because it makes no difference to me. When you are just learning and don’t have any requirements for maintaining backwards compatibility, you can afford to use the latest and greatest.
Introduction
In his hysterical rant on the web and OOP (in which he says the word “bizarre” enough times to qualify as a cover of OMC’s song), Zed Shaw cites OOP being “difficult to teach” as one of its major flaws.
Image credit: taken from here.
That’s a bold claim coming from someone who wrote in his own book:
“Search online for “object-oriented programming” and try to overflow your brain with what you read. Don’t worry if it makes absolutely no sense to you. Half of that stuff makes no sense to me either.” — Learn Python the Hard Way, Third Edition. Zed A. Shaw. 2014.
There are many things in computing that are hard to teach. I don’t think that Object Oriented Programming is one of them.
Motivation
In order to understand why OOP is useful, we’ll start off by not using it, and observe the problems we encounter. To do this, we need a proper example. People often teach OOP in terms of animals or cars, but I think games make more fun and interesting examples.
Screenshot from Dark Sun: Shattered Lands (1993)
A player-controlled character in a game typically has a number of attributes (e.g. name, hit points, etc). In order to group the attributes for our character, we need some kind of record or structure, which in C-style languages would be a struct. We don’t have that in Python, but we can use dictionaries instead.
talorus = { 'name': 'Talorus', 'hitpoints': 30, 'dead': False, 'inventory': [] }
Once we have a way to hold related data, we’ll want to perform some kind of operations on it.
def rename(character, newName): character['name'] = newName def sufferDamage(character, damage): character['hitpoints'] -= damage if (character['hitpoints'] <= 0): character['dead'] = True def receiveItem(character, item): character['inventory'].append(item)
Here’s some example usage:
You’ll notice a common theme across these functions. In all cases, we’re passing our character as the first parameter, and then using some of its attributes within the body of each function. We’re not using OOP yet, but we can already see a natural progression towards the character object being a first class citizen.
However, our current approach has a number of flaws. One of these is that it is easy for any code, anywhere, to tamper with our dictionary’s state.
Our logic from the
sufferDamage() function specifies that characters die only if they run out of hitpoints, so how is our character dead with 26 hitpoints?
Being able to tamper with an object’s state without restriction is a bad thing: it is a violation of encapsulation, which is one of the three pillars of OOP (along with inheritance and polymorphism). We’ll discuss these later.
Classes and Objects
A class is just an abstract template for a type of object. For instance:
class Troll: pass
We’re declaring a Troll class, and using the
pass keyword to indicate that there’s nothing in it for the time being. Once we have this class, then we can create concrete instances:
tom = Troll() bert = Troll() bill = Troll()
In Python, we create instances of a class (i.e. objects) by calling the class name as if it were a function.
An object may have any number of attributes (data members), just like the elements in a dictionary, but accessed using dot notation. Since Python is a dynamic language, it poses no restriction on the attributes that a class must have. We can add and remove attributes on the fly:
A class may define functions (called methods) that operate on an instance of the class:
class Character: def setName(self, newName): self.name = newName
This might look a bit weird, so let’s see some example usage and then discuss what we’re doing here:
The structure of the method might be familiar from the earlier section where we emulated OOP with dictionaries. In this case, we are similarly passing in the object itself as the first parameter, named
self by convention. This extra parameter is required by Python. Through
self, we can then access attributes of the class using dot notation.
What might look really strange here is that although
setName() takes two parameters, we’re calling it with one. That’s because the
self parameter is passed in implicitly when you call a method.
Constructors
A class may define a special method called
__init__() which serves as the class’s constructor. It is usually used to initialise the object’s attributes, and may optionally take parameters which must be supplied when the object is instantiated:
class Character: def __init__(self, name, hitPoints): self.name = name self.hitPoints = hitPoints self.dead = False self.inventory = [] def setName(self, newName): name = newName
Class-Level Variables
Screenshot from Ravenloft: Stone Prophet (1995)
A class may define variables within its scope:
class Monster: totalMonsters = 0 def __init__(self, name, immortal): self.immortal = immortal Monster.totalMonsters += 1
Such class-level variables are not attributes of individual objects. They are shared across all instances of the class, just like static member variables in other languages. The distinction should be clear when you see that you access object attributes using
self and class attributes using the name of the class itself. In this example, the shared totalMonsters counter is incremented every time a new monster is created:
Composition
Screenshot from Dark Sun: Shattered Lands (1993)
In the real world, complex objects are made up (composed) of other objects. The classic example is that a car has an engine (among other parts), but I prefer to stick to the game example. So let’s say we develop our inventory beyond a simple list, and make it into its own class:
class Inventory: def __init__(self): self.items = [] def add(self, item): self.items.append(item) def has(self, item): return item in self.items
While this is a trivial implementation, it can be extended to support more complex operations.
We can now change our Character class to contain the new Inventory class:
class Character: def __init__(self, name, hitPoints): self.name = name self.hitPoints = hitPoints self.dead = False self.inventory = Inventory() def setName(self, newName): name = newName
Composition is used to model a has-a relationship (e.g. Character has an Inventory). As you can see, it’s nothing special. It’s merely a case of a class (e.g. Character) having an attribute whose type is also a class (e.g. Inventory).
Inheritance
Screenshot from Ultima 9: Ascension (1999)
A sword is a very common weapon in games. We can represent a simple sword by the following class:
class Sword: def __init__(self): self.damage = 10 def attack(self, target): print('%d damage done to %s' % (self.damage, target))
Here’s an example usage:
However, there isn’t just one type of sword across all games in existence. Many games have magical swords with all sorts of positive (and negative) effects. One example is a fire sword. It does extra fire damage.
class FireSword: def __init__(self): self.damage = 10 self.fireDamage = 5 def attack(self, target): print('%d damage done to %s' % (self.damage, target)) print('%d extra fire damage done to %s' % (self.fireDamage, target))
As you can see, there’s a lot of repetition here. If we also add classes for lightning swords, poison daggers etc, do we really want to duplicate this code and have to maintain it in several different places?
Fortunately, OOP allows us to create classes that inherit from others.
class FireSword (Sword): pass
The above code states that
FireSword is-a
Sword, and as a result, it inherits all of
Sword‘s attributes and methods:
However, while we are reusing
Sword‘s implementation for
FireSword, we don’t yet have the extra functionality (i.e. extra fire damage) that makes it a fire sword, as we had in the original example. In order to do that, we must override
Sword‘s methods to provide the extra functionality.
class FireSword (Sword): def __init__(self): super().__init__() self.fireDamage = 5 def attack(self, target): super().attack(target) print('%d extra fire damage done to %s' % (self.fireDamage, target))
Here’s an example usage:
By calling
super(), we’re calling the
Sword class’s implementation before doing the extra logic specific to
FireSword. In OOP terminology,
Sword is the base class, parent class or superclass, and
FireSword is the derived class or child class.
When you request an attribute or call a method on a derived class, Python will first look for an implementation in the derived class, and if it’s not there, it will look it up in the base class. This mechanism is what enables inheritance. However, it is also possible to have a method in the derived class to replace or extend the equivalent method in the base class, as we have seen above.
In other OOP languages, methods must usually be marked as virtual to allow them to be overridden. This is not necessary in Python.
“For C++ programmers: all methods in Python are effectively virtual.” — The Python Tutorial – Classes
Python allows a class to inherit from more than one base class. This is known as multiple inheritance, and is strongly discouraged because it makes classes extremely hard to work with. More modern OOP languages such as Java and C# expressly forbid multiple inheritance.
As a humorous aside, if you have a copy of Zed Shaw’s “Learn Python the Hard Way” book, you might want to read his section on “Inheritance vs Composition” for laughs. Shaw wastes almost a whole page with a silly story about a forest and an evil queen, which are supposed to be analogies for inheritance and multiple inheritance. His argument is that inheritance is bad because multiple inheritance is troublesome. That’s a bit like saying we should ban fire because some idiot got burned.
“In object-oriented programming, inheritance is the evil forest. Experienced programmers know to avoid this evil because they know that deep inside the dark forest of.” — Learn Python the Hard Way, Third Edition. Zed A. Shaw. 2014.
Shaw suggests that inheritance should be avoided, and composition should be used instead. For him, the choice between “inheritance versus composition comes down to an attempt to solve the problem of reusable code”. Unfortunately, he misses the point entirely. The main benefit of OOP is to model objects and their relationships. Inheritance models an is-a relationship, whereas composition models a has-a relationship. Code reuse is a practical benefit of both, but does not make them interchangeable.
Encapsulation
In the Motivation section towards the beginning of this article, we saw how emulating OOP with dictionaries results in a situation where the internal state of our classes can be tampered with. Let’s revisit that example, but with OOP:
class Character: def __init__(self, name, hitPoints): self.name = name self.hitPoints = hitPoints self.dead = False def sufferDamage(self, damage): self.hitPoints -= damage if (self.hitPoints <= 0): self.dead = True
Unfortunately, OOP in Python doesn’t do much to protect our internal state, and we can still tamper with it without restriction:
Other OOP languages usually have
private,
protected and
public access modifiers to control access to internal data members of the class; these are enforced by the language. There is none of this in Python. The only thing you can do is follow a convention where private attributes are prefixed by an underscore, and hope that people play fair. It doesn’t stop people from accessing internal state.
Hiding the internal state of a class is called encapsulation. One strong reason why it is important is, as we’ve just seen, to ensure the consistency of that internal state (dead with 255 hit points? huh?). Another reason is to be able to modify the way that state works, without external code being affected.
So right now, we have an attribute called dead (or _dead, if we’re making it private by convention). Let’s add a method that exposes it:
class Character: def __init__(self, name, hitPoints): self._name = name self._hitPoints = hitPoints self._dead = False def sufferDamage(self, damage): self._hitPoints -= damage if (self._hitPoints <= 0): self._dead = True def isDead(self): return self._dead
Code external to this class may now check whether the character is dead by calling the
isDead() method, and should not access
_dead directly:
xanathar.isDead()
This extra method gives us a lot of flexibility because external code does not get to see how we store our internal state. We could, for instance, replace our
_dead attribute with a computation based on
_hitPoints, and the external code would never know the difference:
def isDead(self): return self._hitPoints <= 0
So while in Python you can’t force external code not to touch a class’s internal state (as other OOP languages usually do), it is good practice to hide internal state using the available conventions, and expose only what needs to be exposed.
Polymorphism
Image credit: screenshot of Ultima 7: The Black Gate (1992) using Exult, taken from Let’s Play Archive entry
Typically, a person in a game can talk:
class Person: def Talk(self): print('Hello!')
Sometimes, though, an item can also talk.
class BlackSword: def Talk(self): print('Which of my powers dost thou seek to use?')
Animals, too, may surprise you with their gift of speech.
class SherryTheMouse: def Talk(self): print('Do you have any cheese?')
So here we have three completely unrelated classes, but they all have the same ability: we can call the
Talk() method. When different objects exhibit similar behaviour, and thus we can work with them in a consistent manner, it’s called Polymorphism.
This is useful, for instance, when iterating over different kinds of objects in a loop:
This is unusual in the world of OOP, but since Python uses duck typing, it’s enough that two classes have the same method signature so that you can use them in the same way. In more strongly-typed OOP languages such as C# or Java, the classes would need to have something in common for you to do this (e.g. they implement the same interface, or they share a common base class).
Generics
This section is for developers coming from OOP in other languages. If you’re new to OOP, you may skip it.
Sometimes, you want to make a class have the same behaviour with different data types. For instance, you create a class representing a stack, and it should work the same regardless of whether it’s a stack of integers or of strings.
C++ provides this through templates, and C# and Java provide generics. These are a way to generalise the class implementation across dependent types, while still enforcing type safety.
Since Python is a dynamic language and it does not care what types you use, generics are not necessary. Your stack (or whatever) class will work just as will with integers, strings, or Animals (although I don’t recommend putting elephants at the top of the stack).
Summary
In this article, we’ve covered the basics of OOP in Python.
- Even if you’re not currently doing OOP, you’ll notice that groups of variables and functions will tend to relate to the same entity. There is a natural tendency towards OOP.
- Classes are groups of attributes and functions (methods). They provide a template but are not concrete.
- Objects are concrete instances of classes. Person is a class. Joe is an object.
- A constructor allows you to initialise attributes and pass in any parameters at instantiation time.
- Class-level variables are shared across all instances of that class.
- Composition is when a class contains other classes. It expresses a has-a relationship.
- Inheritance expresses an is-a relationship. If FireSword is-a Sword, then FireSword inherits all of Sword’s attributes and methods, and may override those methods to provide more specialised variants.
- Encapsulation is hiding internal attributes of a class so that external code can’t change them, and so that internal code can be changed without affecting external code. This is not enforced by the language but is upheld by convention.
- Polymorphism is when different objects behave in a similar way. In Python, it works as a result of duck typing.
- Generics aren’t necessary in a language without type safety.
This material includes basic concepts and language syntax, but is merely a starting point.
Mastering OOP is a matter of understanding that it is all about abstraction, and learning to work with abstractions in a way that is beneficial to software (e.g. models problem domains, maximises code reuse, reduces coupling, increases maintainability etc). The three pillars of OOP (inheritance, encapsulation and polymorphism) are basic building blocks of such abstraction. Various design patterns have emerged which demonstrate OOP abstractions put to good use. | https://gigi.nullneuron.net/gigilabs/tag/oop/ | CC-MAIN-2020-05 | en | refinedweb |
mono [options] file [arguments...]
mono-sgen [options] file [arguments...].
This functionality is enabled by setting the MONO_IOMAP environment variable to one of all, drive and case.
See the description for MONO_IOMAP in the environment variables section for more details.
extern void *mono_aot_module_hello_info; mono_aot_register_module (mono_aot_module_hello_info);
For more information about AOT, see:
The configuration is specified using one of more of the following options:,-inlineThe flags that are flagged with [arch-dependency] indicate that the given option if used in combination with Ahead of Time compilation (--aot flag) would produce pre-compiled code that will depend on the current CPU and might not be safely moved to another computer.
mono --runtime=v2.0.50727 program.exe
Using security without parameters is equivalent as calling it with the "cas" parameter.
The following modes are supported:
The security system acts on user code: code contained in mscorlib or the global assembly cache is always trusted.
This is different from --security's verifiable or validil in that these options only check user code and skip mscorlib and assemblies located on the global assembly cache.
The optional OPTIONS argument is a comma separated list of debugging options. These options are turned off by default since they generate much larger and slower code at runtime.
mono --trace=System app.exeClasses are specified with the T: prefix. For example, to trace all calls to the System.String class, use:
mono --trace=T:System.String app.exeAnd individual methods are referenced with the M: prefix, and the standard method notation:
mono --trace=M:System.Console:WriteLine app.exeExceptionseAs previously noted, various rules can be specified at once:
mono --trace=T:System.String,T:System.Random app.exeYou can exclude pieces, the next example traces calls to System.String except for the System.String:Concat method.
mono --trace=T:System.String,-M:System.String:ConcatYou can trace managed to unmanaged transitions using the wrapper qualifier:
mono --trace=wrapper app.exeFinally, namespaces can be specified using the N: prefix:
mono --trace=N:System.Xml
HEXADDR HEXSIZE methodnameCurrently this option is only supported on Linux.
cfg Control Flow Graph (CFG) dtree Dominator Tree code CFG showing code ssa CFG showing code after SSA translation optcode CFG showing code after IR optimizationsSome graphs will only be available if certain optimizations are turned on.eThat will run the program with the default profiler and will do time and allocation profiling.
mono --profile=default:stat,alloc,file=prof.out program.exeW.
It is possible to obtain a stack trace of all the active threads in Mono by sending the QUIT signal to Mono, you can do this from the command line, like this:
kill -QUIT pidWhere).
"armvV [thumb]"where V is the architecture number 4, 5, 6, 7 and the options can be currently be "thunb". Example:
MONO_CPU_ARCH="armv4 thumb" mono ...
Note that /etc/nsswitch.conf will be ignored.
The default is "null" on Unix (and versions of Windows before NT), and "win32" on Windows NT (and higher).
sgen-grep-binprot 0x1234 0x5678 < file
MONO_IOMAP=drive:case export MONO_IOMAPIf you are using mod_mono to host your web applications, you can use the MonoIOMAP directive instead, like this:
MonoIOMAP <appalias> allSeeeNote, however, that Mono currently supports only one profiler module at a time.
Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ
MONO_RTC=4096 mono --profiler=default:stat program.exe
[-]M:method name [-]N:namespace [-]T:class name [-]all [-]program disabled Trace output off upon start.You can toggle trace output on/off sending a SIGUSR2 signal to the program.
valgrind --suppressions=mono.supp mono ...
dtrace -P mono'$target' -l -c mono
As root, run this command:
# setcap cap_net_raw=+ep /usr/bin/mono | https://www.commandlinux.com/man-page/man1/cli.1.html | CC-MAIN-2020-05 | en | refinedweb |
Gson (by Google) is a Java library that can be used to convert a Java object into JSON string. Also, it can used to convert the JSON string into equivalent java object.
There are some other java libraries also capable of doing this conversion, but Gson stands among very few which does not require any pre-annotated java classes OR sourcecode of java classes in any way.
Gson also support the old java classes which had not support of generics in them for type information. It just work with these legacy classes smoothly.
In this gson tutorial, I am giving few examples of very common tasks you can perform with Gson.
Table of Contents 1. Prerequisites and dependency 2. Create Gson object 3. Convert Java objects to JSON format 4. Convert JSON to Java Objects 5. Writing an Instance Creator 6. Custom Serialization and De-serialization 7. Pretty Printing for JSON Output Format 8. Versioning Support 9. More Gson Tutorials
1. Prerequisites and dependency
1.1. POJO Class
Before coming to examples, let’s have a POJO class which we will use in given examples.
public class Employee { private Integer id; private String firstName; private String lastName; private List<String> roles; + ", roles=" + roles + "]"; } }
1.2. Maven dependency
<dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>2.8.5</version> </dependency>
In gradle, use below dependency.
compile group: 'com.google.code.gson', name: 'gson', version: '2.8.5'
2. Create Gson object
Gson object can be created in two ways. First way gives you a quick Gson object ready for faster coding, while second way uses
GsonBuilder to build a more sophisticated Gson object.
//1. Default constructor Gson gson = new Gson(); //2. Using GsonBuilder Gson gson = new GsonBuilder() .disableHtmlEscaping() .setFieldNamingPolicy(FieldNamingPolicy.UPPER_CAMEL_CASE) .setPrettyPrinting() .serializeNulls() .create();
When using
GsonBuilder, there are plenty of other useful options you can provide to
Gson object. Go ahead and check them out.
3. Gson toJson() – Convert Java object to JSON String
To convert object to json, use
toJson() method.
Employee employee = new Employee(); employee.setId(1); employee.setFirstName("Lokesh"); employee.setLastName("Gupta"); employee.setRoles(Arrays.asList("ADMIN", "MANAGER")); Gson gson = new Gson(); System.out.println(gson.toJson(employee));
Program Output.
{"id":1,"firstName":"Lokesh","lastName":"Gupta","roles":["ADMIN","MANAGER"]}
4. 3. Gson fromJson() – Convert JSON string to Object
To parse json to object, use
fromJson() method.
Gson gson = new Gson(); System.out.println( gson.fromJson("{'id':1,'firstName':'Lokesh','lastName':'Gupta','roles':['ADMIN','MANAGER']}", Employee.class));
Program Output.
Employee [id=1, firstName=Lokesh, lastName=Gupta, roles=[ADMIN, MANAGER]]
5. Gson InstanceCreator – when no-args constructor is not present in given object
In most of the cases, Gson library is smart enough to create instances even if any class does not provide default no-args constructor. But, if you found any problem using a class having no-args constructor, you can use
InstanceCreator support. You need to register the
InstanceCreator of a java class type with Gson first before using it.
For example,
Department does not have any default constructor.
public class Department { public Department(String deptName) { this.deptName = deptName; } private String deptName; public String getDeptName() { return deptName; } public void setDeptName(String deptName) { this.deptName = deptName; } @Override public String toString() { return "Department [deptName="+deptName+"]"; } }
And our
Employee class has reference of
Department as:
public class Employee { private Integer id; private String firstName; private String lastName; private List<String> roles; private Department department; //Department reference //Other setters and getters }
To use
Department class correctly, we need to register an InstanceCreator for
Department as below:
class DepartmentInstanceCreator implements InstanceCreator<Department> { public Department createInstance(Type type) { return new Department("None"); } }
Now use the above
InstanceCreator as below.
GsonBuilder gsonBuilder = new GsonBuilder(); gsonBuilder.registerTypeAdapter(Department.class, new DepartmentInstanceCreator()); Gson gson = gsonBuilder.create(); System.out.println( gson.fromJson("{'id':1,'firstName':'Lokesh','lastName':'Gupta', 'roles':['ADMIN','MANAGER'],'department':{'deptName':'Finance'}}", Employee.class));
Program Output.
Employee [id=1, firstName=Lokesh, lastName=Gupta, roles=[ADMIN, MANAGER], department=Department [deptName=Finance]]
6. Gson custom serialization and deserialization
Many times, we need to write/read the JSON values which are not default representation of java object. In that case, we need to write custom serializer and deserializer of that java type.
In our example, I am writing serializer and deserializer for
java.util.Date class, which will help writing the Date format in “dd/MM/yyyy” format.
6.1. Gson custom serializer)); } }
6.2. Gson custom deserializer; } }
6.3. Register custom serializer and deserializer
Now you can register these serializer and deserializer with
GsonBuilder as below:
GsonBuilder gsonBuilder = new GsonBuilder(); gsonBuilder.registerTypeAdapter(Date.class, new DateSerializer()); gsonBuilder.registerTypeAdapter(Date.class, new DateDeserializer());
6.4. Gson custom serializer and deserializer example
Complete example of serializer and deserializer is as below.
Employee employee = new Employee(); employee.setId(1); employee.setFirstName("Lokesh"); employee.setLastName("Gupta"); employee.setRoles(Arrays.asList("ADMIN", "MANAGER")); employee.setBirthDate(new Date()); GsonBuilder gsonBuilder = new GsonBuilder(); gsonBuilder.registerTypeAdapter(Date.class, new DateSerializer()); gsonBuilder.registerTypeAdapter(Date.class, new DateDeserializer()); Gson gson = gsonBuilder.create(); //Convert to JSON System.out.println(gson.toJson(employee)); //Convert to java objects System.out.println(gson.fromJson("{'id':1,'firstName':'Lokesh','lastName':'Gupta', 'roles':['ADMIN','MANAGER'],'birthDate':'17/06/2014'}" , Employee.class));
Program Output.
{"id":1,"firstName":"Lokesh","lastName":"Gupta","roles":["ADMIN","MANAGER"],"birthDate":"17/06/2014"} Employee [id=1, firstName=Lokesh, lastName=Gupta, roles=[ADMIN, MANAGER], birthDate=Tue Jun 17 00:00:00 IST 2014]
7. Gson setPrettyPrinting() – pretty print JSON output
The default JSON output that is provide by Gson is a compact JSON format. This means that there will not be any white-space in the output JSON structure. To generate a more readable and pretty looking JSON use setPrettyPrinting() in
GsonBuilder.
Gson gson = new GsonBuilder().setPrettyPrinting().create(); String jsonOutput = gson.toJson(employee);
Program Output.
{ "id": 1, "firstName": "Lokesh", "lastName": "Gupta", "roles": [ "ADMIN", "MANAGER" ], "birthDate": "17/06/2014" }
8. Gson setVersion() – versioning support
This is excellent feature you can use, if the class file you are working has been modified in different versions and fields has been annotated with
@Since. All you need to do is to use setVersion() method of
GsonBuilder.
GsonBuilder gsonBuilder = new GsonBuilder(); gsonBuilder.registerTypeAdapter(Date.class, new DateSerializer()); gsonBuilder.registerTypeAdapter(Date.class, new DateDeserializer()); //Specify the version like this gsonBuilder.setVersion(1.0); Gson gson = gsonBuilder.create();
8.1. Fields added in various versions in Employee.java
public class Employee { @Since(1.0) private Integer id; private String firstName; private String lastName; @Since(1.1) private List<String> roles; @Since(1.2) private Date birthDate; //Setters and Getters }
Gson @Since example
//Using version 1.0 fields gsonBuilder.setVersion(1.0); Output: {"id":1,"firstName":"Lokesh","lastName":"Gupta"} ///////////////////////////////////////////////////////////// //Using version 1.1 fields gsonBuilder.setVersion(1.1); Output: {"id":1,"firstName":"Lokesh","lastName":"Gupta","roles":["ADMIN","MANAGER"]} ///////////////////////////////////////////////////////////// //Using version 1.2 fields gsonBuilder.setVersion(1.2); Output: {"id":1,"firstName":"Lokesh","lastName":"Gupta","roles":["ADMIN","MANAGER"],"birthDate":"17/06/2014"}
9. More Gson Tutorials
- Gson – GsonBuilder Tutorial
- Gson – Serialize and deserialize JSON
- Gson – Serialize and deserialize Map
- Gson – Serialize and deserialize Set
- Gson – Serialize and deserialize array
- Gson – @SerializedName annotation example
- Gson – Jersey + Gson Example
That’s all for this very useful java gson library to convert java objects from /to JSON. Drop a comment is you have any query or feedback.
Happy Learning !!
Reference
hello
i have a issue, when i convert “gson.toJson(jObj);” then it add \r\n in the response.
i do not want \r\n in my response .
How to resolve it.
Thanks,
Jon
Hi. Try to use .replace.
Some great code examples on various usage of Gson! However, I’ve come across a Json payload I need to parse which contains JSON Arrays which I don’t want, only the Objects. How do I parse a json file and exclude the JSON Arrays?
This is what I used with my JSON Objects:
But whenever it comes across an Array, it crashes with “Expected BEGIN_OBJECT but was BEGIN_ARRAY”
This is my JSON:
(this is just a small snippet, there can be hundreds of “tags_####” arrays and objects)
Any pointers on how to parse the JSON and exclude the Arrays greatly appreciated!
Hi,
I am facing the same issue. Please share if you found a solution for this.
Nice article! I have a basic question if anyone can please answer –
What is the advantage of having corresponding Java classes for JSON response? When we can read and write using JSON libraries. Im not able to figure out exactly why it is needed.
Any example or link along will be helpful
Thanks
All such libraries do one common thing – they convert between java classes and JSON. In fact, you asked the opposite question – in any java program, you have java classes anyway whether you have JSON or not … question should be why you need JSON?? And answer is that JSON is absolutely optional, you can use XML or even serialize the java objects. All works same.
First of all Thank you for GSON article. I am beginner. This article give me fair understand for GSON.I have to deserialize below json data to Java Object.
I am able to parse name and phoneNumber fields. But for the field “deparments”, i am getting Null. Can you please help me, how to parse this?
Json data:
{
“name”: “customer”,
“phoneNumber”: “000000000”,
“deparments”: “xyz,abc,wyz,djkf, iii”
}
CustomerInfo.java
public class CustomerInfo
{
private String name;
private String phoneNumber;
Private String deparments;
// gettters and setters
}
Hey Lokesh very nice tutorial. Can you put some light on how to convert dicom image metadata into JSON format. So that i can store it in mongodb.
Hello Lokesh! First of all, thank you for your tutorial.
I have two question regarding the fields naming in java object.
I have a class, in which all fields there is a ‘m’ prefix.
Second, does the name of the field must match with the name in the json object?
Thank you!
Naming policy is controlled by
setFieldNamingPolicy(FieldNamingPolicy.XXXXXXX). Personally, I prefer to match the names in java and json exactly same, though it’s not mandatory requirement.
Yeah, but there are only four pre-defined constants, non of which seems to solve my m prefix problem.. heh..
Hello Lokesh,
thanks a lot for such an informative and helpful article.
I’m trying to build an android application which needs to pass device information to a custom server and receive some from the server(presently chosen simple socket programming and json objects). can you please suggest suitable library for implementing this communication….i’m a newbie and forsee number of complications in implementing this.
Thanks!
I have very limited information in android. Please ask any android expert.
Hello Lokesh,
i want your hep into converting ArrayList of custom object into Json. Thanx in advance.
This will help you.
good
Could you help me to put ArrayList of custom Object into Json ?
hi.. All,
I am getting DB table column names and data by using hibernate but, i am not able to display out put like this below.
I have to display out put like this below format (out put should be in JSON format) please give me some solutions or advises how i can achieve this.
Required Out Put
——————————–
{
“Table :”[
{
“header”:”EmpID”, “EmpName”
}
{
“Body” : [
{
“row 0 ” : “123”, “ABC”
“row 1 ” : “456”, “XYZ”
}
]
}
]
}
Thanks in Advance
Use pretty printing. e.g
i want to generate json with xml tags in it as below:
Please note that the value of attribute body is not enclosed in double quotes. is there a way to generate such json respnse?
hey.
Thank’s for this nice tutorial.
I’ve had a bit of a problem, and I was wondering if you could help me with it .
Here’s a json I want to parse through java :
{“id”:1,”result”:{“gid”:”1″,”type”:”L”,”help”:”Veuillez entrer votre niveau d’\u00e9tudes \u00e0 l’INPT.”,”language”:”fr”,”sid”:”796246″,”question_order”:”3″,”question”:”\r\n\tvotre niveau d’\u00e9tudes \u00e0 l’INPT :\r\n”,”answeroptions”:{“A1”:{“answer”:”INE1″,”assessment_value”:”0″,”scale_id”:”0″},”A2″:{“answer”:”INE2″,”assessment_value”:”1″,”scale_id”:”0″},”A3″:{“answer”:”INE3″,”assessment_value”:”1″,”scale_id”:”0″}}},”error”:null}
The problem I encounter is with the “answeroptions” parameter : I declared it in my class as an array but it generates errors saying it encountered an object.
How could I parse without loosing generality : I want tp create a methode that can parse it regardless of how many A1,A2,…An elements there are in it.
Thanks in advance mate
Arrays come in [] brackets, not in {} brackets. Are you missing anything?
Yes I know, but the “answeroptions” come as an object, however there’s no way to know how many A1, .. An objects there are so I don’t know how my class should look like.
It’s very interesting question. Thanks for putting it here.
First of all, A1, .. An are not going to be parsed as array; simple reason because all elements in array or list must share same KEY in JSON.
I believe that the structure you need to follow is :
AnswerOptions {
Answer A1;
Answer A2;
Answer A3;
Answer A4;
}
Looking at the kind of response, I do not thing there will be more than some finite options (my guess 5-6) will be there. Also, you can take help of ”question_order”:”3″. May be there is more information you can get in response which can be referred as number of options.
Moreover, all above analysis is pure guess work as I don’t have any idea of work you are trying to do with this JSON. Still. I will fight hard to get a solution for you, generic one.
Thank you.
As a matter of fact this was my very first answer.
The Json I get is from LimeSurvey, a php framework to create surveys, this json answer gives me the properties of a definite question, however the number of answer options in virtually infinte in LimeSurvey .. Thank’s a lot for your help and this great tutorial, if you could find a generic answer it will be awesome, if not I’ll just have to fix a maximum number of Answers.
Thank’s again
I have found a Way to do it.
I just declare “answeroptions” as
and everything goes according to plan, I don’t have to care for how many Ai there are.
Thank you for everything
Awesome, you got it solved. And Thanks for sharing your solution.
Good tutorial
Hello Lokesh,Thanks for the gson article provided by you.I think we need Json when we are using any graphs or hierarchical structures,
Please let me know the real-time scenarios when we can use the json and gson
very nice article as usual.
Thanks | https://howtodoinjava.com/gson/google-gson-tutorial/ | CC-MAIN-2020-05 | en | refinedweb |
isn't if there is a method in a subclass with the exact same signature, the subclass one is suppose to be called over the super?
Account
public class Account { //Declaring instance variables. private int accountNumber; private String ownersName; private double interestRate; protected double balance; public Account(int aNum, String oName, double iRate, double bal) { //User initializing the instance variables. accountNumber = aNum; ownersName = oName; interestRate = iRate; if(bal < 0.0) { balance = 0.0; } else { balance = bal; } } public void withdraw(double amt) { System.out.println("HUH?"); if(amt > 0.0) { balance = balance - amt; } else { balance = balance; } }
SavingsAccount
public class SavingsAccount extends Account { //Initiazling variables. private int countWithdrawals; public SavingsAccount(int aNum, String oName, double iRate, double bal) { //Declaring variables and calling superclass constructor. super(aNum, oName, iRate, bal); countWithdrawals = 0; } //Withdraws specified amount and penalties, if any, and increments the cout total. public void withdraw(int number, double amt) { countWithdrawals++; System.out.println("boo"); balance = balance - amt; if(countWithdrawals > 3) { balance = balance - 30.0; } if(balance < 0.0) { balance = balance - 35.0; } } //The addition to the super's toString() in Account. public String toString() { return "Savings Account\n" + super.toString() + "\nWithdrawals Made: " + countWithdrawals; } } | http://www.dreamincode.net/forums/topic/137967-overriding-methods/ | CC-MAIN-2017-43 | en | refinedweb |
How to Make a Simple Game in Unity 3D
Introduction: How to Make a Simple Game in Unity 3D
games. You can do programming in C#, Java, or Boo, a language similar to Python. In this tutorial, I will walk you through the Unity environment and show you how to make a simple game in Unity.
You do not need any coding experience to follow this Instructable; however, it is recommended because you may have an easier time proofing your code for errors if you have some background some kind of coding language.
This Instructable is based on the RollaBall tutorial on the Unity website. There are a large number of free tutorials that can be found on the Unity tutorial webpage. I created this Instructable mostly for my own practice with Unity, but also to supplement the video tutorials with a set of step-by-step written instructions.
Step 1: Create a New Project
Open Unity3D
Close the "Welcome to Unity" window that pops up by default when you open Unity.
Click File – New Project
Select the location for your project. I like to use one dedicated folder to hold all my Unity projects.
Type the name for your project. In the screenshot, the new project is called "
See the screenshot for how this should look before clicking the Create button.
Click “Create.”
Step 2: Customize the Layout
The first thing you may want to do is customize the layout. Every window can be clicked and dragged into position. Alternatively, you can use the default layouts provided with Unity by clicking the drop bar under Layout in the top left of the screen. I like the Tall layout, though I find it helpful to put the Game view below the Scene view.
There are five main windows that you are using most of the time with Unity. They are the Scene, Game, Hierarchy, Project, and Inspector windows. See the five pictures at the top of the step for images of each window.
Scene – this is where the game making happens. It shows what elements you have in your game and where they are relative to each other. There is a block in the upper right corner showing the spatial orientation of the scene.
Game – shows the view that the main camera sees when the game is playing. You can test out your game in this window by clicking the Play button in the top, center of the screen.
Hierarchy – lists all elements you have added to the scene. This is the main camera by default. You can create new elements by clicking Create and selecting the type of object you want. This can also be done by using the GameObject dropdown menu at the top of the screen.
Project – shows the files being used for the game. You can create folders, scripts, etc. by clicking Create under the Project window.
Inspector – this is where you customize aspects of each element that is in the scene. Just select an object in the Hierarchy window or double-click on an object in the Scene window to show its attributes in the Inspector panel.
Step 3: Save the Scene & Set Up the Build
Click File – Save Scene. Save the scene under the folder [Project Name] – Assets. Assets is a pre-made folder into which you will want to store your scenes and scripts. You may want to create a folder called Scenes within Assets because the Assets folder can get messy.
Save the scene as Scene or Main or something like that.
Click File – Build Settings.
Add current scene to build.
Select desired platform. There are a lot of options, including computers, game systems, and smart phones, but if you are creating projects for the first time, you will most likely want to select Web Player or PC/Mac/Linux Standalone.
Click Player Settings at the bottom of the Build Settings window. This opens the Player Settings options in the Inspector. Here, you can change the company name, the product (game) name, default icon, etc.
Close out of the Build Settings window. You will come back to this when you are ready to finish your game.
Step 4: Create the Stage
The simplest way to create a stage in Unity is to add cubes.
To do this, go to Game Object – Create Other – Cube, or use the Create menu in the Hierarchy window. Add a cube.
Reset the cube’s transform by right-clicking “Transform” in the Inspector panel. It is good practice to do this whenever you create a new Game Object.
Select the cube in the Hierarchy. Rename it “Wall” by double clicking its name in Hierarchy or using the Inspector panel.
Scale the cube in the X direction to make it long and wall-like.
Right click “Wall” in the Hierarchy panel, and duplicate it three times, so you have four walls. It will look like you only have one wall because they are identical and therefore occupying the same point in space. Drag them into position and/or use the transform options for each cube to make an arrangement that looks like an arena.
Note: To look around the scene view, click the middle mouse button to pan and scroll to zoom in and out. Click and drag while holding the ALT key to rotate the view.
Create an empty Game Object, using the Game Object dropdown (Create Empty) at the top of the screen. Call it “Stage.” Reset its transform.
Select all four “Walls” and drag them under the “Stage” Game Object.
Add a plane Game Object by selecting Create in the Hierarchy panel and use it for the floor. Rename it "Floor," and drag it under Stage in the Hierarchy.
Note: you need to hit enter after renaming, or else the change may not take effect.
Give the floor a -0.5 transform in the Y-direction to ensure it lines up neatly with the four walls.
Make the floor's scale in the X, Y, and Z directions 1/10 of the scale you used to size the walls.
Step 5: Create the Player
You can download characters from various places online, such as the Unity Store, but for this tutorial, we’re just going to use one of the built-in Game Objects for the player.
Go to Game Objects – Create Other – Sphere.
Select the sphere in the Hierarchy, and rename it “Player.” Reset its transform.
Now we need physics. Make the player subject to the laws of physics by clicking Add Component at the bottom of the Inspector panel with the player selected. Add Physics – Rigidbody. Leave all the default settings.
You will notice that each object comes with a variety of “components” added to it that you can see in the Inspector. Each cube, sphere, etc. has a component called a “collider.” This is the physical area of the screen where that object is considered to take up space. If you turn off a collider, than the object becomes like a ghost, able to pass through other objects. (See video for what happens when you turn off the player's collider component.) You can turn components on and off by checking and unchecking the box next to the component’s name.
Step 6: Making the Player Move Around
Select the player in the Hierarchy.
Minimize components that you don’t want to see open in the Inspector by clicking the down arrows to the left of the name of each component. This will clear up your workspace a bit.
Click Add Component at the bottom of the Inspector window. Select New Script, name the script something like "PlayerController," and choose a programming language. I use CSharp. Click Create and Add.
For the sake of keeping files organized, open the Assets folder in the Project window, and create a folder called Scripts. Put your new script in this folder.
To open the script for editing, double click the script’s name in the Inspector, or open it from the Project window. This opens a programming environment called MonoDevelop.
Note: If this is your first time coding, you should know that it can be really nitpicky. Make sure that you are consistent with spelling, cases, and having opening and closing brackets, parentheses, curly brackets, quotations, etc. Also, watch out for errors that result from not having a semicolon at the end of a line of code.
There should already be two sections included in your code by default: void Start () and void Update (). Start runs as soon as the object comes into the game, and update runs continuously while the object is in the game. We will add a third, called FixedUpdate to handle physics-related protocols. It should look like this:
void FixedUpdate () { }
Before we can input commands, we need to declare variables. This is done toward the top of the page, within the curly brackets following Public Class PlayerController (or similar) : Monobehaviour, but before the void Start() function. For movement, we will use a variable called “speed,” which we can adjust to determine the speed at which our character moves around the arena. Declare the variable type (float) and name (speed) like so:
public float speed;
The semicolon tells the program that this is the end of the line of code. You will get an error if you forget to include a semicolon at the end of every/most line(s) of code, so don’t leave it out!
Under FixedUpdate, declare two more floats, moveHorizontal and moveVertical. These take on values depending on the user’s keyboard commands, and FixedUpdate updates them every frame.
float moveHorizontal = Input.GetAxis(“Horizontal”); float moveVertical = Input.GetAxis(“Vertical”);
Case matters.
Still within FixedUpdate, create a new Vector3, a type of variable with three dimensions useful for moving objects around in 3D space. This will take on the value of the user’s input for horizontal and vertical movement, and will be zero in the up/down direction because in this game, the player can only move in two dimensions.
Vector3 movement = new Vector3(moveHorizontal,0.0f,moveVertical);
Finally, input a force on the player to move it around, using rigidbody.AddForce, a protocol built in to the player’s rigidbody component.
rigidbody.AddForce(movement*speed*Time.deltaTime);
Time.deltaTime is used to make movement smoother. We will adjust the speed variable later, in the Unity editor.
Save the CSharp file, and switch back to Unity.
Go to the Inspector panel for the player, and look at the movement script you have just created. There should be a box for your public variable, speed. You can change the value of public variables using the Inspector.
For now, make speed equal a number between 100-1000, and click the play button at the top, middle of the screen. You should be able to move the ball around using Unity’s default movement keys, either ASWD or the arrow keys.
Click the play button again to exit out of testing mode.
Step 7: Add Lighting
Create an empty Game Object and call it “Lights.” Do this by clicking GameObject in the top toolbar and selecting “create empty.”
Create a directional light by selecting the option from “create” toolbar in the Hierarchy panel. Name it “Main Light.” Make it a child object of Lights by dragging it in the Hierarchy onto the Lights game object. This is a similar concept to putting a file into a folder.
With Main Light selected, change the light settings in the Inspector panel by changing Shadow Type to “Soft Shadows” and Resolution to “Very High Resolution.”
In the Inspector panel, change the main light’s rotation to angle it down over the arena. I used 30X, 60Y, 0Z.
Right click the Main Light in the Hierarchy panel to duplicate it. Name the duplicate “Fill Light,” and child it under Lights.
Dampen the intensity of the Fill Light by changing the color to a light blue tint and reducing the Intensity field to 0.1 (in the Inspector).
Change Shadows to “No Shadows.”
Angle the Fill Light the opposite direction of the main light. For me, this was (330, 300, 0).
Step 8: Fine-tune the Camera Angle
We want the camera to be angled down over the arena, so select the Main Camera in the Hierarchy, and adjust its transform until the image in camera preview (the bottom right of the Scene panel, with the camera selected) looks good.
I used (0, 10.5, -10) for position, and (45, 0, 0) for rotation.
You can also drag the camera around in the scene view to position it, if you wish.
Step 9: Make the Camera Follow the Player
We want the camera to follow the player around the screen as it moves. For this purpose, create a script called “cameraMovement” by adding a new script component to the Main Camera in the Inspector panel. Double click the script to open it in MonoDevelop.
This script will access another Game Object, the player, so you must declare this before the script’s Start() function by writing
public GameObject player;
Create a Vector3 called “offset” by writing
private Vector3 offset;
Under the Start() function, assign the value of offset to be
offset=transform.position;
which is the (x,y,z) position of the camera.
Under a function called LateUpdate (), define the camera’s position as the player’s position plus some offset:
void LateUpdate () { transform.position=player.transform.position+offset;}
Save the script and go back to Unity.
We need to assign a Game Object to the “player” we defined in the cameraMovement script. Select the Main Camera and look at the Inspector panel. Under the cameraMovement script, there should be a box called “Player.” It is currently assigned to None (GameObject). Drag the Player from the Hierarchy into this box to assign the player game object to the cameraMovement script.
Be sure to drag the new script into the scripts folder (in the Project panel), which you created under Assets.
Try out the game by clicking the play button at the top, center of the screen. You should be able to move the player around with the arrow keys and the camera should follow your movement.
Save the scene and save the project.
Step 10: Make Items
Create a new Game Object. It can be a sphere, a cube, a capsule, or a cylinder. I used a cube.
Call it “Item.”
Tag the Item as “item” by selecting Tags, and creating a new tag called “item,” then going back to Tags for that game object and selecting the new "item" tag that you created. Tag all your items as items. Make sure you match the spelling and capitalization exactly.
Place the Item into an empty Game Object called “Items.”
Reset their transforms.
Add a rigidbody to the Item.
Duplicate the Item a bunch of times and place the copies around the arena.
Step 11: Make the Player Collect the Items & Display the Score
Open the player movement script from the Inspector panel with the Player game object selected, and modify the script to allow the player to collect, and keep track of, the items it has collected.
Make two declarations: one is a variable that keeps track of your score, and the other is a GUI text that will display your score on the scene view.
private int count; public GUIText countText;
Under the function void Start(), initialize count and CountText, a function we will write later.
count=0; CountText();
Write a new function for what happens when the Player collides with the Items. This should be its own section, just like the void Start() and void Update sections.
void OnTriggerEnter(Collider other){ if (other.gameObject.tag == “item”)
{other.gameObject.SetActive(false);
count=count+1;
CountText();}
}
Write the CountText function, which will update the score on the GUI display.
Void CountText(){ countText.text="Count: " + count.ToString();
}
Save the code and switch back to Unity.
Select all your items, make sure they are tagged as items, and check the button “Is Trigger” in the Box Collider component of the Inspector.
Also check the “Is Kinematic” button under rigidbody. This prevents your items from falling through the floor, essentially by turning off gravity.
For the countText, create a new GUI (graphical user interface) Text using the Create option under Hierarchy.
Set the GUI Text’s transform to (0,1,0) and give it a pixel offset of (10, -10) in the GUIText component on the Inspector panel.
Drag the GUI Text into the Count Text box on the Inspector with the Player selected.
Step 12: Make Hazards
These hard-to-see panels will launch the player into the air, and possibly over the edge of the arena, in which case it will be game over. Making hazards is a similar process to making items.
Create new empty game object called “Hazards.”
Create a new Quad and call it “Hazard.”
Tag it as hazard, and check “Is Trigger.”
Change its color so you can see it by selecting Mesh Renderer in the Inspector, with the hazard selected, and changing its material. Click the drop-down by Materials, and use the little gray circle to the right of the box to select a different material than the default gray one for the hazard. I had a white material pre-installed, so I used that.
Change the hazard’s rotation to 90 about the X axis and lower its Y height to -0.4 so it is a small white square lying just over the floor of the arena.
Edit the Player script, under the OnTriggerEnter() function, so that it accounts for the possibility that the object the player runs into is a hazard, and not an item. Tell the player to jump if it hits the hazard.
void OnTriggerEnter(Collider other){ if(other.gameObject.tag=="item"){ other.gameObject.SetActive(false); count = count + 1; CountText(); } if(other.gameObject.tag=="hazard"){ other.gameObject.SetActive(false); Vector3 jump = new Vector3(0.0f, 30, 0.0f); rigidbody.AddForce (jump * speed * Time.deltaTime); }
Save the code,go back to the Unity editor, and duplicate the hazard a few times.
Position the hazards around the arena, and try out the game!
i keep getting an error on line of code using vector3 saying error ',' expected
can you please help me!!!
when you declare the Vector3 (probably something like "Vector3 movement = new Vector3(moveHorizontal,0.0f,moveVertical);" you have to make sure there are 3 values (x,y,z), so look at the line the console is telling you there's an error and make sure you didn't missed the "," between values.
The development of games has undergone a significant change in recent years. With the advancement of smartphones and other devices, other forms of play became popular and smaller games, different from those of "console", emerged. From this, a portion of the market spent a being occupied by so-called indie developers, or individual developers. With this new market, new tools for maids such as Unity 3D and Corona, or improved ones such as Unreal, to increase productivity, making developers focus does not really matter - gameplay, the way the game is played - , And need to spend less time with details of game physics, effects and animations, for example.
Error at line 12: rigidbody.AddForce (movement * speed * Time.deltaTime) shows an error- UnityEngine Component does not contain a definition for AddForce and no extension method...Please how do i fix this. I use Unity v.5.5.1f1
Help! Whenever I make a new project, it says, "Bind failed, error: An attempt was made to access a socket in a way forbidden by it's access permissions. Help please!
thank you very much for this simple and cool tutorial!!
i have the code
using UnityEngine;
using System.Collections;
public class playercontrol : MonoBehaviour {
public float speed;
void FixedUpdate () {
float moveHorizontal = Input.GetAxis (“Horizontal”);
float moveVertical = Input.GetAxis (“Vertical”);
Vector3 movement = new Vector3(moveHorizontal,0.0f,moveVertical);
GetComponent<Rigidbody>().AddForce (movement * speed * Time.deltaTime);
}
}
and i get the error the when i try to change player movement speed: ascociated script cannot be loaded please fix any compile errors and assign a valid script
script name must be the same as class name, in your case "playercontrol"
Great guide! if you are looking for more tips about creating a game I highly recommend blog.theknightsofunity.com
can anyone put the finished code of step 6?
it doesn't move and it doesn't tell me anything about an error
Step 11. It says select "Player Movement" script. Is this meant to be the "Player Controller" script?
Can you post screenshots of what your scripts should look like AFTER you finish them? I was able to follow everything up until 11, and now I've got a ton of errors with my script, and then step 12. to create a GUI, I don't have the option for a GUI, I can click "create>UI>Text" but I don't have a text transform or pixel offset option.
In Unity 5, you have to then use "Add Component" on that to add "GUIText". Extra step there.
The way you used to add GUIText has been changed with the new update. To do this, you need to create a new GameObject as usual but click on the "Add Component" and type GUI in the search field then choose GUI Text from the results.
Thanks. You first add Hierarchy>Create>UI>Text and then "Add component". This worked for me with Unity 5.
The player falls down the cube and cant be seen after running the c# script. I dont have any idea. Please help.
Check inspector to see if "player" is Rigid? i.e Use Gravity/Is Kinematic.
I've created the GUI (create>UI>text) but cannot find a Count Text
box, instead a Canvas Renderer-option has appeared after editing the
script as this step tells me.
Could you give the actual code or something?
Hi
Just add, to the top of script:
using UnityEngine.UI;
to the declarations:
public Text countText;
how to play in android?
use Unity remote 4
might have to look on the google play store is #1 try #2 is save it to your external SD card and then reinsert it into your phone after you've made the the game
Like this..
Please help me! I cant move the player with custom speeds, but my unity has no error.
I have assigned a Game Object to the "player", after that it was gray screen in Game mode (only gray screen, without anything). If I remove link to the object from the field "player", all works, but camera doesn't move after the player.
What's wrong?
I'm using Unit 5.2 and the last line should be
GetComponent<Rigidbody>().AddForce (movement * speed * Time.deltaTime);
Thanks!
The Line "{other.gameObject.SetActive(false);" doesn't work. You receive the error cs0201 which isOnly assignment, call, increment, decrement, and new object expressions can be used as a statement
my fix was "other.gameObject.SetActive(false);"
thanks! very helpful | http://www.instructables.com/id/How-to-make-a-simple-game-in-Unity-3D/ | CC-MAIN-2017-43 | en | refinedweb |
CodePlexProject Hosting for Open Source Software
I have what is probably the simplest and easiest question ever, but after two days of banging I'm ready to jump out a window. Note the source is mooched directly from the example.
public class Message
{
public string Address { get; set; }
[JsonProperty(TypeNameHandling = TypeNameHandling.All)]
public object Body { get; set; }
}
public class SearchDetails
{
public string Query { get; set; }
public string Language { get; set; }
}
public void serialize()
{
Message message = new Message();
message.Address = "";
message.Body = new SearchDetails
{
Query = "Json.NET",
Language = "en-us"
};
string json = JsonConvert.SerializeObject(message, Formatting.Indented); // <- barfs right here
}
The error message I've got (and I've tried this a dozen different ways) is:
InitializeContract(contract) tosses an error: Method not found: 'Boolean System.Runtime.Serialization.DataContractAttribute.get_IsReference()'.I'm using the latest release of 3.5 and developing in Visual Studio 2008 (.NET 3.5)
InitializeContract(contract) tosses an error: Method not found: 'Boolean System.Runtime.Serialization.DataContractAttribute.get_IsReference()'.
[json.net]
Did you get anywhere with this? I am having exactly the same problem.
Are you sure you want to delete this post? You will not be able to recover it later.
Are you sure you want to delete this thread? You will not be able to recover it later. | https://json.codeplex.com/discussions/240861 | CC-MAIN-2017-43 | en | refinedweb |
MAPPATH(3) Library Routines MAPPATH(3)
_mapPath, _mapPathGS, _setPathMapping - (mapPath) convert GS/OS paths to Unix-style paths.
#include <gno/gno.h> void _setPathMapping (int toggle); char *_mapPath (char *pathname); GSStringPtr _mapPathGS (GSStringPtr pathname);
These routines are intended for use by application programmers who are porting programs from Unix systems. The POSIX 1003.1 standard indicates that the pathname separator (that character which is used to delimit the components of a pathname) must be the slash ('/') character. However, GS/OS internally uses the colon (':') character. This can cause problems with programs that make assumptions about the pathname separator. The routines _mapPath and _mapPathGS, if active, map all occurances of the ':' character in pathname to the '/' character. These routines are intended to be used whenever a pathname is returned from a GS/OS call. No assumption is made as to the existance of the file nor the validity of the filename for any given file system. On success, these routines return their original arguments. The only time _mapPath or _mapPathGS can fail is if mapping is active and path- name contains both the ':' and '/' characters. In such a case, the routine will return NULL and pathname will be unchanged. For compatibility with native IIgs programs, _mapPath and _mapPathGS are by default null operations -- pathname is not modified. In order to activate mapping, the function _setPathMapping must be called with a non-zero toggle. Although the choice of whether or not to do mapping is usually only made once in a program, mapping can be turned off again by calling _setPathMapping with a zero toggle. These functions are used in various parts of libc. Those routines mak- ing use of this mapping list the fact in their respective man pages.
In cases where it is desirable to avoid the overhead of a function call, the value of the global integer __force_slash may be checked. If it is non-zero, the mapping function should be called: if (__force_slash) { _mapPath(filename); }
Devin Reade <gdr@gno.org>
GS/OS Reference Manual. GNO 11 December 1996 MAPPATH(3) | http://www.gno.org/gno/man/man3/mapPath.3.html | CC-MAIN-2017-43 | en | refinedweb |
In my android application, I have two Fragments. Parent Fragment contains list of available Filter Types and when a particular Filter Type is clicked (in Parent Fragment - Yellow Background) corresponding Child Fragment (Pink Background) opens with list of available options for selected filter type. My requirement is once User select/deselect an option in child fragment, it should reflect/update option count (Green color) in parent Fragment.
Please check attached wireframe.
You can use Otto Bus for comunications between Fragments, fragments-activities, services, etc.
Maybe, the first time you can be a little weird if you have not used before but it is very powerful and very easy to use. You can find the library and a tutorial here:
An example. In your adapter or where you have your item click event you cand send a Object by the Bus.
In your bus you invoque the post method and pass the object. (I recommended create a singleton for Bus).
The singleton Bus Provider.
/** * Canal de comunicacion */ public class BusProvider { private static final Bus REST_BUS = new Bus(ThreadEnforcer.ANY); private static final Bus UI_BUS = new Bus(); private BusProvider() {}; public static Bus getRestBusInstance() { return REST_BUS; } public static Bus getUIBusInstance () { return UI_BUS; } }
You send a Object in the bus (in your child fragment) like this:
BusProvider.getUIBusInstance().post(itemSelected);
And in your parent fragment you subscribe for this event:
@Subscribe public void activitySelected(final Item itemSelected) { }
Hope it helps you!! | https://codedump.io/share/QHUU4qw22HI4/1/updating-parent-fragment-from-child-fragment | CC-MAIN-2017-43 | en | refinedweb |
LingerOption Class
Specifies whether a Socket will remain connected after a call to Close and the length of time it will remain connected, if data remains to be sent.
For a list of all members of this type, see LingerOption Members.
System.Object
System.Net.Sockets.LingerOption
[Visual Basic] Public Class LingerOption [C#] public class LingerOption [C++] public __gc class LingerOption [JScript] public class LingerOption
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Remarks
There may still be data available in the outgoing network buffer after you close the Socket. If you want to specify the amount of time that the Socket will attempt to transmit unsent data after closing, create a LingerOption with the enabled with the enabled parameter set to false. In this case, the Socket will close immediately and any unsent data will be lost. Once created, pass the LingerOption to the Socket.SetSocketOption method. If you are sending and receiving data with a TcpClient, then pass the LingerOption to the TcpClient.LingerState method.
By default, lingering is enabled with a zero time-out. As a result, the Socket will attempt to send pending data until there is no data left in the outgoing network buffer.
Example
[Visual Basic, C#, C++] The following example sets a previously created Socket to linger one second after calling the Close method.
[Visual Basic] Dim myOpts As New LingerOption(True, 1) mySocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Linger, _ myOpts) [C#] LingerOption myOpts = new LingerOption(true,1); mySocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Linger, myOpts); [C++] LingerOption* myOpts = new LingerOption(true,1); mySocket->SetSocketOption(SocketOptionLevel::Socket, SocketOptionName::Linger, myOpts);
)
See Also
LingerOption Members | System.Net.Sockets Namespace | https://msdn.microsoft.com/en-us/library/system.net.sockets.lingeroption(v=vs.71).aspx | CC-MAIN-2017-43 | en | refinedweb |
Submission + - Create uniform namespace using autofs with NFS 3
BlueVoodoo writes: "Do you have trouble accessing data exported from multiple file servers? If so, try using open source implementations of autofs and Lightweight Directory Access Protocol (LDAP), with Network File System (NFS) Version 3, to access data under the same global mount point." | https://slashdot.org/submission/615388/create-uniform-namespace-using-autofs-with-nfs-3 | CC-MAIN-2017-43 | en | refinedweb |
speed - ios check internet connection without reachability
How to check for an active Internet connection on iOS or macOS? (20)
I would like to check to see if I have an Internet connection on iOS using the Cocoa Touch libraries or on macOS using the Cocoa libraries.
I came up with a way to do this using an
NSURL. The way I did it seems a bit unreliable (because even Google could one day be down and relying on a third iOS 3.0 and macOS 10.4) and if so, what is a better way to accomplish this?
Download the Reachability file,
And add
CFNetwork.frameworkand 'SystemConfiguration.framework' in framework
Do #import "Reachability.h"
First: Add
CFNetwork.framework in framework
Code:
ViewController"); } }
Very simple.... Try these steps:
Step 1: Add the
SystemConfiguration framework into your project.
Step 2: Import the following code into your
header file.
#import <SystemConfiguration/SystemConfiguration.h>
Step 3: Use the following method
Type 1:
- (BOOL) currentNetworkStatus { [UIApplication sharedApplication].networkActivityIndicatorVisible = NO; BOOL connected; BOOL isConnected; const char *host = ""; SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithName(NULL, host); SCNetworkReachabilityFlags flags; connected = SCNetworkReachabilityGetFlags(reachability, &flags); isConnected = NO; isConnected = connected && (flags & kSCNetworkFlagsReachable) && !(flags & kSCNetworkFlagsConnectionRequired); CFRelease(reachability); return isConnected; }
Type 2:
Import header :
#import "Reachability.h"
- (BOOL)currentNetworkStatus { Reachability *reachability = [Reachability reachabilityForInternetConnection]; NetworkStatus networkStatus = [reachability currentReachabilityStatus]; return networkStatus != NotReachable; }
Step 4: How to use:
- (void)CheckInternet { BOOL network = [self currentNetworkStatus]; if (network) { NSLog(@"Network Available"); } else { NSLog(@"No Network Available"); } }
First: Add
CFNetwork.framework in framework
Code:
ViewController.m
#import "Reachability"); } }
Important: This check should always be performed asynchronously. The majority of answers below are synchronous so be careful otherwise you'll freeze up your app.
Swift
1) Install via CocoaPods or Carthage:
2) Test reachability via closures") }
Objective-C
1) Add
SystemConfiguration framework to the project but don't worry about including it anywhere
2) Add Tony Million's version of
Reachability.h and
Reachability.m to the project (found here:)]; }
Important Note: The
Reachability class is one of the most used classes in projects so you might run into naming conflicts with other projects. If this happens, you'll have to rename one of the pairs of
Reachability.h and
Reachability.m files to something else to resolve the issue.
Note: The domain you use doesn't matter. It's just testing for a gateway to any domain.
Apart from reachability you may also use the Simple Ping helper library. It works really nice and is simple to integrate.
Apple provides a sample app which does exactly this:
First download the reachability class and put reachability.h and reachabilty.m file in your Xcode.
The best way is to make a common Functions class (NSObject) so that you can use it any class. These are two methods for a network connection reachability check:
+(BOOL) reachabiltyCheck { NSLog(@"reachabiltyCheck"); BOOL status =YES; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil]; Reachability * reach = [Reachability reachabilityForInternetConnection]; NSLog(@"status : %d",[reach currentReachabilityStatus]); if([reach currentReachabilityStatus]==0) { status = NO; NSLog(@"network not connected"); } reach.reachableBlock = ^(Reachability * reachability) { dispatch_async(dispatch_get_main_queue(), ^{ }); }; reach.unreachableBlock = ^(Reachability * reachability) { dispatch_async(dispatch_get_main_queue(), ^{ }); }; [reach startNotifier]; return status; } +(BOOL)reachabilityChanged:(NSNotification*)note { BOOL status =YES; NSLog(@"reachabilityChanged"); Reachability * reach = [note object]; NetworkStatus netStatus = [reach currentReachabilityStatus]; switch (netStatus) { case NotReachable: { status = NO; NSLog(@"Not Reachable"); } break; default: { if (!isSyncingReportPulseFlag) { status = YES; isSyncingReportPulseFlag = TRUE; [DatabaseHandler checkForFailedReportStatusAndReSync]; } } break; } return status; } + (BOOL) connectedToNetwork { // Create zero addy struct sockaddr_in zeroAddress; bzero(&zeroAddress, sizeof(zeroAddress)); zeroAddress.sin_len = sizeof(zeroAddress); zeroAddress.sin_family = AF_INET; // Recover reachability flags SCNetworkReachabilityRef defaultRouteReachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *)&zeroAddress); SCNetworkReachabilityFlags flags; BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags); CFRelease(defaultRouteReachability); if (!didRetrieveFlags) { NSLog(@"Error. Could not recover network reachability flags"); return NO; } BOOL isReachable = flags & kSCNetworkFlagsReachable; BOOL needsConnection = flags & kSCNetworkFlagsConnectionRequired; BOOL nonWiFi = flags & kSCNetworkReachabilityFlagsTransientConnection; NSURL *testURL = [NSURL URLWithString:@""]; NSURLRequest *testRequest = [NSURLRequest requestWithURL:testURL cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:20.0]; NSURLConnection *testConnection = [[NSURLConnection alloc] initWithRequest:testRequest delegate:self]; return ((isReachable && !needsConnection) || nonWiFi) ? (testConnection ? YES : NO) : NO; }
Now you can check network connection in any class by calling this class method.
Here is how I do it in my apps: While a 200 status response code doesn't guarantee anything, it is stable enough for me. This doesn't require as much loading as the NSData answers posted here, as mine just checks the HEAD response.
Swift Code
func checkInternet(flag:Bool, completionHandler:(internet:Bool) -> Void) { UIApplication.sharedApplication().networkActivityIndicatorVisible = true let url = NSURL(string: "") let request = NSMutableURLRequest(URL: url!) request.HTTPMethod = "HEAD" request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData request.timeoutInterval = 10.0 NSURLConnection.sendAsynchronousRequest(request, queue:NSOperationQueue.mainQueue(), completionHandler: {(response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in UIApplication.sharedApplication().networkActivityIndicatorVisible = false let rsp = response as! NSHTTPURLResponse? completionHandler(internet:rsp?.statusCode == 200) }) } func yourMethod() { self.checkInternet(false, completionHandler: {(internet:Bool) -> Void in if (internet) { // "Internet" aka Apple's region universal URL reachable } else { // No "Internet" aka Apple's region universal URL un-reachable } }) }
Objective-C Code
typedef void(^connection)(BOOL); - (void)checkInternet:(connection)block { NSURL *url = [NSURL URLWithString:@""]; NSMutableURLRequest *headRequest = [NSMutableURLRequest requestWithURL:url]; headRequest.HTTPMethod = @"HEAD"; NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration ephemeralSessionConfiguration]; defaultConfigObject.timeoutIntervalForResource = 10.0; defaultConfigObject.requestCachePolicy = NSURLRequestReloadIgnoringLocalAndRemoteCacheData; NSURLSession *defaultSession = [NSURLSession sessionWithConfiguration:defaultConfigObject delegate:self delegateQueue: [NSOperationQueue mainQueue]]; NSURLSessionDataTask *dataTask = [defaultSession dataTaskWithRequest:headRequest completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { if (!error && response) { block([(NSHTTPURLResponse *)response statusCode] == 200); } }]; [dataTask resume]; } - (void)yourMethod { [self checkInternet:^(BOOL internet) { if (internet) { // "Internet" aka Apple's region universal URL reachable } else { // No "Internet" aka Apple's region universal URL un-reachable } }]; }
I found it simple and easy to use library SimplePingHelper.
Sample code: chrishulbert/SimplePingHelper (GitHub)
I like to keep things simple. The way I do this is:
//Class.h #import "Reachability.h" #import <SystemConfiguration/SystemConfiguration.h> - (BOOL)connected; //Class.m - (BOOL)connected { Reachability *reachability = [Reachability reachabilityForInternetConnection]; NetworkStatus networkStatus = [reachability currentReachabilityStatus]; return networkStatus != NotReachable; }
Then, I use this whenever I want to see if I have a connection:
if (![self connected]) { // Not connected } else { // Connected. Do some Internet stuff }
This method doesn't wait for changed network statuses in order to do stuff. It just tests the status when you ask it to.
I've used the code in this discussion, and it seems to work fine (read the whole thread!).
I haven't tested it exhaustively with every conceivable kind of connection (like ad hoc Wi-Fi).
If you're using
AFNetworking you can use its own implementation for internet reachability status.
The best way to use
AFNetworking is to subclass the
AFHTTPClient class and use this class to do your network connections.
One of the advantages of using this approach is that you can use
blocks to set the desired behavior when the reachability status changes. Supposing that I've created a singleton subclass of
AFHTTPClient (as said on the "Subclassing notes" on AFNetworking docs) named
BKHTTPClient, I'd do something like:
BKHTTPClient *httpClient = [BKHTTPClient sharedClient]; [httpClient setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) { if (status == AFNetworkReachabilityStatusNotReachable) { // Not reachable } else { // Reachable } }];
You could also check for Wi-Fi or WLAN connections specifically using the
AFNetworkReachabilityStatusReachableViaWWAN and
AFNetworkReachabilityStatusReachableViaWiFi enums (more here).
Only the Reachability class has been updated. You can now use:
Reachability* reachability = [Reachability reachabilityWithHostName:@""]; NetworkStatus remoteHostStatus = [reachability currentReachabilityStatus]; if (remoteHostStatus == NotReachable) { NSLog(@"not reachable");} else if (remoteHostStatus == ReachableViaWWAN) { NSLog(@"reachable via wwan");} else if (remoteHostStatus == ReachableViaWiFi) { NSLog(@"reachable via wifi");}
The Reachability class is OK to find out if the Internet connection is available to a device or not...
But in case of accessing an intranet resource:
Pinging the intranet server with the reachability class always returns true.
So a quick solution in this scenario would be to create a web method called
pingme along with other webmethods on the service.
The
pingme should return something.
So I wrote the following method on common functions
-(BOOL)PingServiceServer { NSURL *url=[NSURL URLWithString:@""]; NSMutableURLRequest *urlReq=[NSMutableURLRequest requestWithURL:url]; [urlReq setTimeoutInterval:10]; NSURLResponse *response; NSError *error = nil; NSData *receivedData = [NSURLConnection sendSynchronousRequest:urlReq returningResponse:&response error:&error]; NSLog(@"receivedData:%@",receivedData); if (receivedData !=nil) { return YES; } else { NSLog(@"Data is null"); return NO; } }
The above method was so useful for me, so whenever I try to send some data to the server I always check the reachability of my intranet resource using this low timeout URLRequest.
There's a nice-looking, ARC- and GCD-using modernization of Reachability here:
This used to be the correct answer, but it is now outdated as you should subscribe to notifications for reachability instead. This method checks synchronously:
You can use Apple's Reachability class. It will also allow you to check if Wi-Fi is enabled:
Reachability* reachability = [Reachability sharedReachability]; [reachability setHostName:@""]; // Set your host name here NetworkStatus remoteHostStatus = [reachability remoteHostStatus]; if (remoteHostStatus == NotReachable) { } else if (remoteHostStatus == ReachableViaWiFiNetwork) { } else if (remoteHostStatus == ReachableViaCarrierDataNetwork) { }
The Reachability class is not shipped with the SDK, but rather a part of this Apple sample application. Just download it, and copy Reachability.h/m to your project. Also, you have to add the SystemConfiguration framework to your project.
Use. It's easier than adding libraries and write code by yourself.
Using Apple's Reachability code, I created a function that'll check this correctly without you having to include any classes.
Include the SystemConfiguration.framework in your project.
Make some imports:
#import <sys/socket.h> #import <netinet/in.h> #import <SystemConfiguration/SystemConfiguration.h>
Now just call this function:
/* Connectivity testing code pulled from Apple's Reachability Example: */ +(BOOL)hasConnectivity { struct sockaddr_in zeroAddress; bzero(&zeroAddress, sizeof(zeroAddress)); zeroAddress.sin_len = sizeof(zeroAddress); zeroAddress.sin_family = AF_INET; SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, (const struct sockaddr*)&zeroAddress); if (reachability != NULL) { //NetworkStatus retVal = NotReachable; SCNetworkReachabilityFlags flags; if (SCNetworkReachabilityGetFlags(reachability, &flags)) { if ((flags & kSCNetworkReachabilityFlagsReachable) == 0) { // If target host is not reachable return NO; } if ((flags & kSCNetworkReachabilityFlagsConnectionRequired) == 0) { // If target host is reachable and no connection is required // then we'll assume (for now) that your on Wi-Fi return YES; } if ((((flags & kSCNetworkReachabilityFlagsConnectionOnDemand ) != 0) || (flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) != 0)) { // ... and the connection is on-demand (or on-traffic) if the // calling application is using the CFSocketStream or higher APIs. if ((flags & kSCNetworkReachabilityFlagsInterventionRequired) == 0) { // ... and no [user] intervention is needed return YES; } } if ((flags & kSCNetworkReachabilityFlagsIsWWAN) == kSCNetworkReachabilityFlagsIsWWAN) { // ... but WWAN connections are OK if the calling application // is using the CFNetwork (CFSocketStream?) APIs. return YES; } } } return NO; }
And it's iOS 5 tested for you.
- (void)viewWillAppear:(BOOL)animated { NSString *URL = [NSString stringWithContentsOfURL:[NSURL URLWithString:@""]]; return (URL != NULL ) ? YES : NO; }
Or use the Reachability class.
There are two ways to check Internet availability using the iPhone SDK:
1. Check the Google page is opened or not.
2. Reachability Class
For more information, please refer to Reachability (Apple Developer).
-(void)newtworkType { NSArray *subviews = [[[[UIApplication sharedApplication] valueForKey:@"statusBar"] valueForKey:@"foregroundView"]subviews]; NSNumber *dataNetworkItemView = nil; for (id subview in subviews) { if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarDataNetworkItemView") class]]) { dataNetworkItemView = subview; break; } } switch ([[dataNetworkItemView valueForKey:@"dataNetworkType"]integerValue]) { case 0: NSLog(@"No wifi or cellular"); break; case 1: NSLog(@"2G"); break; case 2: NSLog(@"3G"); break; case 3: NSLog(@"4G"); break; case 4: NSLog(@"LTE"); break; case 5: NSLog(@"Wifi"); break; default: break; } } | https://code.i-harness.com/en/q/108935 | CC-MAIN-2020-05 | en | refinedweb |
Introduction
You may find the title of this article somewhat misleading. Yes, I have written about this subject before, but as I have said many a time: There are many ways to skin a cat. What I will show you today will also make use of batch files to delete the program, but with one caveat. The program must first be closed.
Now, why should a program such as this exist?.
Practical
Create a new C# or Visual Basic.NET Console application. After the application has loaded, add these namespaces.
C#
using System; using System.Diagnostics; using System.IO; using System.Reflection; using System.Threading;
VB.NET
Imports System.IO Imports System.Reflection Imports System.Threading
The namespaces import the Reflection and threading and file classes so that we can utilize them throughout our code.
Add the next code for the Sub Main procedure:
C#
static void Main(string[] args) { string strBatch = string.Empty; string strEXE = Assembly.GetExecutingAssembly() .CodeBase.Replace("", string.Empty).Replace("/", "\\"); strBatch += "@ECHO OFF\n"; strBatch += "ping 127.0.0.1 > nul\n"; strBatch += "echo j | del /F "; strBatch += strEXE + "\n"; strBatch += "echo j | del DelApp.bat"; File.WriteAllText("DelApp.bat", strBatch); Process.Start("DelApp.bat"); }
VB.NET
Private Sub Main(ByVal args As String()) Dim strBatch As String = String.Empty Dim strEXE As String = Assembly.GetExecutingAssembly() _ .CodeBase.Replace("", String.Empty).Replace("/", "\") strBatch += "@ECHO OFF" & vbLf strBatch += "ping 127.0.0.1 > nul" & vbLf strBatch += "echo j | del /F " strBatch += strEXE & vbLf strBatch += "echo j | del DelApp.bat" File.WriteAllText("DelApp.bat", strBatch) Process.Start("DelApp.bat") End Sub
A batch file gets created. It checks to see if the application is still open. If it is not open, it executes the created batch file.
Add another way.
C#
static void SelfDestruct() { string strBatch = "DelApp.bat"; using (StreamWriter swBatch = + "\""); } Process.Start(new ProcessStartInfo() { Arguments = "/C " + strBatch + " & Del " + strBatch, WindowStyle = ProcessWindowStyle.Hidden, CreateNoWindow = true, FileName = "cmd.exe" }); }
VB.NET
Private Sub SelfDestruct() Dim strBatch As String = "DelApp.bat" Using swBatch As StreamWriter = & """") End Using Process.Start(New ProcessStartInfo() With { .Arguments = "/C " & strBatch & " & _ Del " & strBatch, .WindowStyle = ProcessWindowStyle.Hidden, .CreateNoWindow = True, .FileName = "cmd.exe" }) End Sub
When you call this sub procedure, it keeps on checking the task list to see if the application is open or not. If it is no longer open, it deletes it.
Conclusion
It is not difficult creating a self-destructing program, but use this with caution. As outlined above, ensure that there are valid reasons for this. Until next time, happy coding and destructing! | https://mobile.codeguru.com/csharp/.net/net_general/tipstricks/creating-another-self-destruct-program.html | CC-MAIN-2020-05 | en | refinedweb |
How YOU can Learn Mock testing in .NET Core and C# with Moq
Chris Noring
Updated on
・11 min read
Follow me on Twitter, happy to take your suggestions on topics or improvements /Chris
When we test we just want to test one thing - the business logic of the method. Often our method needs the help of dependencies to be able to carry out its job properly. Depending on what these dependencies answer - there might be several paths through a method. So what is Mock testing? It's about testing only one thing, in isolation, by mocking how your dependencies should behave.
In this article we will cover the following:
- Why test, it's important to understand why we test our code. Is it to ensure our code works? Or maybe we are adding tests for defensive reasons so that future refactors don't mess up the business logic?
- What to test, normally this question has many answers. We want to ensure that our method does what it says it does, e.g
1+1equals
2. We might also want to ensure that we test all the different paths through the method, the happy path as well as alternate/erroneous paths. Lastly, we might want to assert that a certain behavior takes place.
- Demo, let's write some code that has more than one execution path and introduce the Mocking library
Moqand see how it can help us fulfill the above.
References
xUnit testing
This page describes how to use xUnit with .Net Core
nUnit testing
This page describes how to use nUnit with .Net Core.
dotnet test, terminal command description
This page describes the terminal command
dotnet testand all the different arguments you can call it with.
dotnet selective test
This page describes how to do selective testing and how to set up filters and query using filters.
.Net Core Series on NuGet, Serverless and much more
-
Why test
As we mentioned already there are many answers to this question. So how do we know? Well, I usually see the following reasons:
- Ensuring Quality, because I'm not an all-knowing being I will make mistakes. Writing tests ensures that at least the worst mistakes are avoided.
- Is my code testable, before I've written tests for my code it might be hard to tell whether it lends itself to be tested. Of course, I need to ask myself at this point whether this code should be tested. My advice here if it's not obvious what running the method will produce or if there is more than one execution path - it should be tested.
- Being defensive, you have a tendency to maintain software over several years. The people doing the maintaining might be you or someone else. One way to communicate what code is important is to write tests that absolutely should work regardless of what refactorings you, or anyone else, attempts to carry out.
- Documentation, documentation sounds like a good idea at first but we all know that out of sync documentation is worse than no documentation. For that reason, we tend to not write it in the first place, or maybe feel ok with high-level documentation only or rely on tools like Swagger for example. Believe it or not but tests are usually really good documentation. It's one developer to another saying, this is how I think the code should be used. So for the sake of that future maintainer, communicate what your intentions were/are.
What to test
So what should we test? Well, my first response here is all the paths through the method. The happy path as well as alternate paths.
My second response is to understand whether we are testing a function to produce a certain result like
1+1 equals
2 or whether it's more a behavior like - we should have been paid before we can ship the items in the cart.
Demo - let's test it
What are we doing? Well, we have talked repeatedly about that Shopping Cart in an e-commerce application so let's use that as an example for our demo.
This is clearly a case of behavior testing. We want the Cart items to be shipped to a customer providing we got paid. That means we need to verify that the payment is carried out correctly and we also need a way to assert what happens if the payment fails.
We will need the following:
- A
CartController, will contain logic such as trying to get paid for a cart's content. If we are successfully paid then ship the items in the cart to a specified address.
- Helper services, we need a few helper services to figure this out like:
ICartService, this should help us calculate how much the items in cart costs but also tell us exactly what the content is so we can send this out to a customer once we have gotten paid.
IPaymentService, this should charge a card with a specified sum
IShipmentService, this should be able to ship the cart content to a specific address
Creating the code
We will need two different .NET Core projects for this:
- a webapi project, this should contain our production code and carry out the business logic as stated by the
CartControllerand its helper services.
- a test project, this project will contain all the tests and a reference to the above project.
The API project
For this project, this could be either an app using the template
mvc,
webapp or
webapi
First, let's create a solution. Create a directory like so:
mkdir <new directory name> cd <new directory name>
Thereafter create a new solution like so:
dotnet new sln
To create our API project we just need to instantiate it like so:
dotnet new webapi -o api
and lastly add it to the solution like so:
dotnet sln add api/api.csproj
Controllers/CartController.cs
Add the file
CartController.cs under the directory
Controllers and give it the following content:
using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; using Microsoft.AspNetCore.Mvc; using Services; namespace api.Controllers { [ApiController] [Route("[controller]")] public class CartController { private readonly ICartService _cartService; private readonly IPaymentService _paymentService; private readonly IShipmentService _shipmentService; public CartController( ICartService cartService, IPaymentService paymentService, IShipmentService shipmentService ) { _cartService = cartService; _paymentService = paymentService; _shipmentService = shipmentService; } [HttpPost] public string CheckOut(ICard card, IAddressInfo addressInfo) { var result = _paymentService.Charge(_cartService.Total(), card); if (result) { _shipmentService.Ship(addressInfo, _cartService.Items()); return "charged"; } else { return "not charged"; } } } }
Ok, our controller is created but it has quite a few dependencies in place that we need to create namely
ICartService,
IPaymentService and
IShipmentService.
Note how we will not create any concrete implementations of our services at this point. We are more interested in establishing and testing the behavior of our code. That means that concrete service implementations can come later.
Services/ICartService.cs
Create the file
ICartService.cs under the directory
Services and give it the following content:
namespace Services { public interface ICartService { double Total(); IEnumerable<CartItem> Items(); } }
This interface is just a representation of a shopping cart and is able to tell us what is in the cart through the method
Items() and how to calculate its total value through the method
Total().
Services/IPaymentService.cs
Let's create the file
IPaymentService.cs in the directory
Services and give it the following content:
namespace Services { public interface IPaymentService { bool Charge(double total, ICard card); } }
Now we have a payment service that is able to take
total for the amount to be charged and
card which is debit/credit card that contains all the needed information to be charged.
Services/IShipmentService.cs
For our last service let's create the file
IShipmentService.cs under the directory
Services with the following content:
using System; using System.Generic; namespace Services { public interface IShipmentService { void Ship(IAddressInfo info, IEnumerable<CartItem> items); } }
This contains a method
Ship() that will allow us to ship a cart's content to the customer.
Services/Models.cs
Create the file
Models.cs in the directory
Services with the following content:
namespace Services { public interface IAddressInfo { public string Street { get; set; } public string Address { get; set; } public string City { get; set; } public string PostalCode { get; set; } public string PhoneNumber { get; set; } } public interface ICard { public string CardNumber { get; set; } public string Name { get; set; } public DateTime ValidTo { get; set; } } public interface CartItem { public string ProductId { get; set; } public int Quantity { get; set; } public double Price{ get; set; } } }
This contains some supporting interfaces that we need for our services.
Creating a test project
Our test project is interested in testing the behavior of
CartController. First off we will need a test project. There are quite a few test templates supported in .NET Core like
nunit,
xunit and
mstest. We'll go with
nunit.
To create our test project we type:
dotnet new nunit -o api.test
Let's add it to the solution like so:
dotnet sln add test/test.csproj
Thereafter add a reference of the API project to the test project, so we are able to test the API project:
dotnet add test/test.csproj reference api/api.csproj
Finally, we need to install our mocking library
moq, with the following command:
dotnet add package moq
Moq, how it works
Let's talk quickly about our Mock library
moq. The idea is to create a concrete implementation of an interface and control how certain methods on that interface responds when called. This will allow us to essentially test all of the paths through code.
Creating our first Mock
Let's create our first Mock with the following code:
var paymentServiceMock = new Mock<IPaymentService>();
The above is not a concrete implementation but a Mock object. A Mock can be:
- Instructed, you can tell a mock that if a certain method is called then it can answer with a certain response
- Verified, verification is something you carry out after your production code has been called. You carry this out to verify that a certain method has been called with specific arguments
Instruct our Mock
Now we have a Mock object that we can instruct. To instruct it we use the method
Setup() like so:
paymentServiceMock.Setup(p => p.Charge()).Returns(true)
Of course, the above won't compile, we need to give the
Charge() method the arguments it needs. There are two ways we can give the
Charge() method the arguments it needs:
- Exact arguments, this is when we give it some concrete values like so:
var card = new Card("owner", "number", "CVV number"); paymentServiceMock.Setup(p => p.Charge(114,card)).Returns(true)
- General arguments, here we can use the helper
It, which will allow us to instruct the method
Charge()that any values of a certain data type can be passed through:
paymentServiceMock.Setup(p => p.Charge(It.IsAny<double>(),card)).Returns(true)
Accessing our implementation
We will need to pass an implementation of our Mock when we call the actual production code. So how do we do that? There's an
Object property on the Mock that represents the concrete implementation. Below we are using just that. We first construct
cardMock and then we pass
cardMock.Object to the
Charge() method.
var cardMock = new Mock<ICard>(); paymentServiceMock.Setup(p => p.Charge(It.IsAny<double>(),cardMock.Object)).Returns(true)
Add unit tests
Let's rename the default test file we got to
CartControllerTest.cs. Next, let's discuss our approach. We want to:
- Test all the execution paths, there are currently two different paths through our CartController depending on whether
_paymentService.Charge()answers with
trueor
false
- Write two tests, we need at least two different tests, one for each execution path
- Assert, we need to ensure that the correct thing happens. In our case, that means if we successfully get paid then we should ship, so that means asserting that the
shipmentServiceis being called.
Let's write our first test:
// CartControllerTest.cs [Test] public void ShouldReturnCharged() { // arrange paymentServiceMock.Setup(p => p.Charge(It.IsAny<double>(), cardMock.Object)).Returns(true); // act var result = controller.CheckOut(cardMock.Object, addressInfoMock.Object); // assert shipmentServiceMock.Verify(s => s.Ship(addressInfoMock.Object, items.AsEnumerable()), Times.Once()); Assert.AreEqual("charged", result); }
We have three phases above.
Arrange
Let's have a look at the code:
paymentServiceMock.Setup(p => p.Charge(It.IsAny<double>(), cardMock.Object)).Returns(true);
here we are setting things up and saying that if our
paymentService.Charge() method is called with any value
It.IsAny<double>() and with a card object
cardMock.Object then we should return
true, aka
.Returns(true). This means we have set up a happy path and are ready to go to the next phase Act.
Act
Here we call the actual code:
var result = controller.CheckOut(cardMock.Object, addressInfoMock.Object);
As we can see above we get the answer assigned to the variable
result. This takes us to our next phase, Assert.
Assert
Let's have a look at the code:
shipmentServiceMock.Verify(s => s.Ship(addressInfoMock.Object, items.AsEnumerable()), Times.Once()); Assert.AreEqual("charged", result);
Now, there are two pieces of assertions that take place here. First, we have a Mock assertion. We see that as we are calling the method
Verify() that essentially says: I expect the
Ship() method to have been called with an
addressInfo object and a
cartItem list and that it was called only once. That all seems reasonable, our
paymentService says it was paid, we set it up to respond
true.
Next, we have a more normal-looking assertion namely this code:
Assert.AreEqual("charged", result);
It says our
result variable should contain the value
charged.
A second test
So far we tested the happy path. As we stated earlier, there are two paths through this code. The
paymentService could decline our payment and then we shouldn't ship any cart content. Let's see what the code looks like for that:
[Test] public void ShouldReturnNotCharged() { // arrange); }
Above we see that we have again the three phases Arrange, Act and Assert.
Arrange
This time around we are ensuring that our
paymentService mock is returning
false, aka payment bounced.
paymentServiceMock.Setup(p => p.Charge(It.IsAny<double>(), cardMock.Object)).Returns(false);
Act
This part looks exactly the same:
var result = controller.CheckOut(cardMock.Object, addressInfoMock.Object);
Assert
We are still testing two pieces of assertions - behavior and value assertion:
shipmentServiceMock.Verify(s => s.Ship(addressInfoMock.Object, items.AsEnumerable()), Times.Never()); Assert.AreEqual("not charged", result);
Looking at the code above we, however, are asserting that
shipmentService is not called
Times.Never(). That's important to verify as that otherwise would lose us money.
The second assertion just tests that the
result variable now says
not charged.
Full code
Let's have a look at the full code so you are able to test this out for yourself:
// CartControllerTest.cs using System; using Services; using Moq; using NUnit.Framework; using api.Controllers; using System.Linq; using System.Collections.Generic; namespace test { public class Tests { private CartController controller; private Mock<IPaymentService> paymentServiceMock; private Mock<ICartService> cartServiceMock; private Mock<IShipmentService> shipmentServiceMock; private Mock<ICard> cardMock; private Mock<IAddressInfo> addressInfoMock; private List<CartItem> items; [SetUp] public void Setup() { cartServiceMock = new Mock<ICartService>(); paymentServiceMock = new Mock<IPaymentService>(); shipmentServiceMock = new Mock<IShipmentService>(); // arrange cardMock = new Mock<ICard>(); addressInfoMock = new Mock<IAddressInfo>(); // var cartItemMock = new Mock<CartItem>(); cartItemMock.Setup(item => item.Price).Returns(10); items = new List<CartItem>() { cartItemMock.Object }; cartServiceMock.Setup(c => c.Items()).Returns(items.AsEnumerable()); controller = new CartController(cartServiceMock.Object, paymentServiceMock.Object, shipmentServiceMock.Object); } [Test] public void ShouldReturnCharged() { paymentServiceMock.Setup(p => p.Charge(It.IsAny<double>(), cardMock.Object)).Returns(true); // act var result = controller.CheckOut(cardMock.Object, addressInfoMock.Object); // assert // myInterfaceMock.Verify((m => m.DoesSomething()), Times.Once()); shipmentServiceMock.Verify(s => s.Ship(addressInfoMock.Object, items.AsEnumerable()), Times.Once()); Assert.AreEqual("charged", result); } [Test] public void ShouldReturnNotCharged() {); } } }
Final thoughts
So we have managed to test out the two major paths through our code but there are more tests, more assertions we could be doing. For example, we could ensure that the value of the Cart corresponds to what the customer is actually being charged. As well all know in the real world things are more complicated. We might need to update the API code to consider timeouts or errors being thrown from the Shipment service as well as the payment service.
Summary
I've hopefully been able to convey some good reasons for why you should test your code. Additionally, I hope you think the library
moq looks like a good candidate to help you with the more behavioral aspects of your code.
Great post! You can increase the readability of your tests by using FluentAssertions and it makes your Assert statements independent from the test library.
Magic string are no go imo for tests. Replacing expected value for a variable increase readability as well.
yea.. It wasn't meant to look like a clean code, perfect looking test but rather show the usage of moq.. Agree with you though.. no magic strings | https://practicaldev-herokuapp-com.global.ssl.fastly.net/dotnet/how-you-can-learn-mock-testing-in-net-core-and-c-with-moq-4ikd | CC-MAIN-2020-05 | en | refinedweb |
Django debug extension
Project description
The Everbug is a lightweight Django middleware for Chrome extension with easy install. One of the advantages: the response body of target page remains clean and unchanged.
Special summary: * Database queries with explains (Multiple database support) * Context variables * Profiles functions (cProfile through decorator) * Support ajax requests
Installing
For Django:
Run "pip install everbug". Add "everbug" to your INSTALLED_APPS in settings.py. Append "everbug.middleware.Tracer" to MIDDLEWARE or MIDDLEWARE_CLASSES in settings.py.
For Chrome: _chrome_ext_ For Firefox: _firefox_ext_
Usage
“Context” works for any view which has a “context_data”. “Queries” works as-is for all databases in “DATABASES” section. “Profile” works through decorator (based on builtin cProfile). By default, profile output is truncated to 20 lines.
Example usage:
from everbug.shortcuts import profile @profile def sample_method(): // some code here ...
Call @profile with argument for full view, for example:
@profile(short=False) def sample_method(): // some code here ...
Running the tests
docker-compose up -d docker exec -it everbug tox
Requirements
Project details
Release history Release notifications
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages. | https://pypi.org/project/everbug/ | CC-MAIN-2020-05 | en | refinedweb |
Vanilla quick introduction
OVN is a distributed SDN controller implementing virtual networks with the help OVS. Even though it is positioned as a CMS-independent controller, the main use case is still OpenStack. OVN was designed to address the following limitations of vanilla OpenStack networking:
- Security groups could not be implemented directly on OVS ports and, therefore, required a dedicated Linux bridge between the VM and the OVS integration bridge.
- Routing and DHCP agents required dedicated network namespaces.
- NAT was implemented using a combination of network namespaces, iptables and proxy-ARP.:
- OVN ML2 Plugin - performs translation between Neutron data model and OVN logical data model stored in Northbound DB.
- OVN northd - the brains of OVN, translates the high level networking abstractions (logical switches, routers and ports) into logical flows. These logical flows are not yet OpenFlow flows but similar in concept and a very powerful abstraction. All translated information is stored in Southbound DB.
- OVN controllers - located on each compute node, receive identical copies of logical flows (centralised network view) and exchange logical port to overlay IP binding information via the central Southbound DB. This information is used to perform logical flow translation into OpenFlow which are then programmed into the local OVS instance.
If you want to learn more about OVN architecture and use cases, OpenStack OVN page has an excellent collection of resources for further reading.
OpenStack installation.
cd /etc/yum.repos.d/ wget wget
On the controller node, generate a sample answer file and modify settings to match the IPs of individual nodes. Optionally, you can disable some of the unused components like Nagios and Ceilometer similar to how I did it in my earlier post.
yum install -y openstack-packstack crudini packstack --gen-answer-file=/root/packstack.answer crudini --set --existing defautl CONFIG_COMPUTE_HOSTS 169.254.0.12,169.254.0.13 crudini --set --existing defautl CONFIG_CONTROLLER_HOST 169.254.0.11 crudini --set --existing defautl CONFIG_NETWORK_HOSTS 169.254.0.11 packstack --answer-file=/root/packstack.answer
After the last step we should have a working 3-node OpenStack lab, similar to the one depicted below. If you want to learn about how to automate this process, refer to my older posts about OpenStack and underlay Leaf-Spine fabric build using Chef.
OVN Build.
yum -y update kernel reboot
The official OVS installation procedure for CentOS7 is pretty accurate and requires only a few modifications to account for the packages missing in the minimal CentOS image I’ve used as a base OS.
yum install rpm-build autoconf automake libtool systemd-units openssl openssl-devel python python-twisted-core python-zope-interface python-six desktop-file-utils groff graphviz procps-ng libcap-ng libcap-ng-devel yum install selinux-policy-devel kernel-devel-`uname -r` git git clone && cd ovs ./boot.sh ./configure make rpm-fedora RPMBUILD_OPT="--without check" make rpm-fedora-kmod
At the end of the process we should have a set of rpms inside the
ovs/rpm/rpmbuild/RPMS/ directory.
OVN Install.
OpenStack preparation
First, we need to make sure all Compute nodes have a bridge that would provide access to external provider networks. In my case, I’ll move the
eth1 interface under the OVS
br-ex on all Compute nodes.
DEVICE=eth1 NAME=eth1 DEVICETYPE=ovs TYPE=OVSPort OVS_BRIDGE=br-ex ONBOOT=yes BOOTPROTO=none
IP address needs to be moved to
br-ex interface. Below example is for Compute node #2:
ONBOOT=yes DEFROUTE=yes IPADDR=169.254.0.12 PREFIX=24 GATEWAY=169.254.0.1 DNS1=8.8.8.8 DEVICE=br-ex NAME=br-ex DEVICETYPE=ovs OVSBOOTPROTO=none TYPE=OVSBridge
At the same time OVS configuration on Network/Controller node will need to be completely wiped out. Once that’s done, we can remove the Neutron OVS package from all nodes.
yum remove openstack-neutron-openvswitch
OVS packages installation
Now everything is ready for OVN installation. First step is to install the kernel module and upgrade the existing OVS package. Reboot may be needed in order for the correct kernel module to be loaded.
rpm -i openvswitch-kmod-2.6.90-1.el7.centos.x86_64.rpm rpm -U openvswitch-2.6.90-1.el7.centos.x86_64.rpm reboot
Now we can install OVN. Controllers will be running the
ovn-northd process which can be installed as follows:
rpm -i openvswitch-ovn-common-*.x86_64.rpm rpm -i openvswitch-ovn-central-*.x86_64.rpm systemctl start ovn-northd
The following packages install the
ovn-controller on all Compute nodes:
rpm -i openvswitch-ovn-common-*.x86_64.rpm rpm -i openvswitch-ovn-host-*.x86_64.rpm systemctl start ovn-controller
The last thing is to install the OVN ML2 plugin, a python library that allows Neutron server to talk to OVN Northbound database.
yum install python-networking-ovn
OVN Configuration:
$ ovs-sbctl show Chassis "d03bdd51-e687-4078-aa54-0ff8007db0b5" hostname: "compute-3" Encap geneve ip: "10.0.0.4" options: {csum="true"} Encap vxlan ip: "10.0.0.4" options: {csum="true"} Chassis "b89b8683-7c74-43df-8ac6-1d57ddefec77" hostname: "compute-2" Encap vxlan ip: "10.0.0.2" options: {csum="true"} Encap geneve ip: "10.0.0.2" options: {csum="true"}
This means that all instances of a distributed OVN controller located on each compute node have successfully registered with Southbound OVSDB and provided information about their physical overlay addresses and supported encapsulation types.
(Optional) Automating everything with Chef:
git clone cd chef-unl-os chef-client -z -E lab ovn.rb
Test topology setup
Now we should be able to create a test topology with two tenant subnets and an external network interconnected by a virtual router.
neutron net-create NET-RED neutron net-create NET-BLUE neutron subnet-create --name SUB-BLUE NET-BLUE 10.0.0.0/24 neutron subnet-create --name SUB-RED NET-RED 20.0.0.0/24 neutron net-create NET-EXT --provider:network_type flat \ --provider:physical_network extnet \ --router:external --shared neutron subnet-create --name SUB-EXT --enable_dhcp=False \ --allocation-pool=start=169.254.0.50,end=169.254.0.99 \ --gateway=169.254.0.1 NET-EXT 169.254.0.0/24 neutron router-create R1 neutron router-interface-add R1 SUB-BLUE neutron router-interface-add R1 SUB-RED neutron router-gateway-set R1 NET-EXT
When we attach a few test VMs to each subnet we should be able to successfully ping between the VMs, assuming the security groups are setup to allow ICMP/ND.
curl | glance \ image-create --name='IMG-CIRROS' \ --visibility=public \ --container-format=bare \ --disk-format=qcow2 nova aggregate-create AGG-RED AZ-RED nova aggregate-create AGG-BLUE AZ-BLUE nova aggregate-add-host AGG-BLUE compute-2 nova aggregate-add-host AGG-RED compute-3 nova boot --flavor m1.tiny --image 'IMG-CIRROS' \ --nic net-name=NET-BLUE \ --availability-zone AZ-BLUE \ VM1 nova boot --flavor m1.tiny --image 'IMG-CIRROS' \ --nic net-name=NET-RED \ --availability-zone AZ-RED \ VM2 nova boot --flavor m1.tiny --image 'IMG-CIRROS' \ --nic net-name=NET-BLUE \ --availability-zone AZ-RED \ VM3 openstack floating ip create NET-EXT openstack server add floating ip VM3 169.254.0.53
. | https://networkop.co.uk/blog/2016/11/27/ovn-part1/ | CC-MAIN-2020-05 | en | refinedweb |
I'm working on building a python class structure that makes it easier to swap out strategies and risk models while using multi-timeFrames techniques. I've been off in my own code world for a few months, and I came back and went to run it and hit an Attribute error I'm unfamiliar with.During the algorithm initialization, the following exception has occurred: AttributeError : 'ForexHolding' object has no attribute 'TotalMargin'
at Initialize in main.py:line 39
at __init__ in SymbolBox.py:line 37
at __init__ in TradeManagment.py:line 13
:: self.TotalMargin = self.symbol.TotalMargin /5
AttributeError : 'ForexHolding' object has no attribute 'TotalMargin'
I found these two links, but I'm still having a hard time seeing which classes I should be indexing through/ what part of the API I'm incorrectly calling.
It centers around the QC portfolio. The code below is going to be slightly broken up, I'm including the code in each class that produces the error. It's during __init__ so the rest of the code seems unecessary.
class Main
self.symbols = ['EURUSD','NZDUSD']
for i in self.symbols:
sym = self.AddSecurity(SecurityType.Forex, i, Resolution.Hour,leverage= 100).Symbol
self.allTicks[sym] = SymbolBox(i, sym, self.timeFrames, self)
class SymbolBox
def __init__(self, symbol,sym, timeFrames, QCAlgorithm):
'''
inits all variables and classes needed by each symbol to trade.
Handles all day for each Symbol inside its' respecive class.
'''
self.tick = symbol
self.s = sym
self.algo = QCAlgorithm
self.symbol = QCAlgorithm.Portfolio[sym]
self.TM = TradeManagment(QCAlgorithm,sym)
class TradeManagment
def __init__(self,QcAlgo,symbol):
self.algo = QcAlgo
self.symbol = QcAlgo.Portfolio[symbol]
#symbol is pulling only the string, not the class. Need to decide how to place
self.TotalMargin = self.symbol.TotalMargin /5
My leading theory so far is that when I call self.AddSecurity().Symbol in main I'm pulling out and storing one call too deep into the class and getting the wrong variable? | https://www.quantconnect.com/forum/discussion/6555/039-forexholding-039-object-has-no-attribute-039-totalmargin-039/ | CC-MAIN-2020-05 | en | refinedweb |
Namespace: DevExpress.Web.Mvc
Assembly: DevExpress.Web.Mvc5.v19.2.dll
public class ImageEditExtension : EditorExtension
Public Class ImageEditExtension Inherits EditorExtension
To declare the Image in a View, invoke the ExtensionsFactory.Image helper method. This method returns the Image extension that is implemented by the ImageEditExtension class.
To configure the Image extension, pass the ImageEditSettings object to the ExtensionsFactory.Image helper method as a parameter. The ImageEditSettings object contains all the Image extension settings.
Refer to the Image Overview topic to learn how to add the Image extension to your project. | https://docs.devexpress.com/AspNet/DevExpress.Web.Mvc.ImageEditExtension | CC-MAIN-2020-05 | en | refinedweb |
ComponentDesigner Class
Extends the design mode behavior of a component.
Assembly: System.Design (in System.Design.dll)
System.ComponentModel.Design.ComponentDesigner
System.Diagnostics.Design.ProcessDesigner
System.Diagnostics.Design.ProcessModuleDesigner
System.Diagnostics.Design.ProcessThreadDesigner
System.Messaging.Design.MessageDesigner
System.ServiceProcess.Design.ServiceControllerDesigner
System.Web.UI.Design.HtmlControlDesigner
System.Windows.Forms.Design.ComponentDocumentDesigner
System.Windows.Forms.Design.ControlDesigner
The ComponentDesigner base designer class provides a simple designer that can extend the behavior of an associated component in design mode.
ComponentDesigner provides an empty IDesignerFilter interface implementation, whose methods can be overridden to adjust the attributes, properties and events of the associated component at design time.
You can associate a designer with a type using a DesignerAttribute. For an overview of customizing design-time behavior, see Extending Design-Time Support.
The ComponentDesigner class implements a special behavior for the property descriptors of inherited components. An internal type named InheritedPropertyDescriptor is used by the default ComponentDesigner implementation to stand in for properties that are inherited from a base class. There are two cases in which these property descriptors are added.
To the root object itself, which is returned by the IDesignerHost.RootComponent property, because you are inheriting from its base class.
To fields found in the base class of the root object. Public and protected fields from the base class are added to the designer so that they can be manipulated by the user.
The InheritedPropertyDescriptor class modifies the default value of a property, so that the default value is the current value at object instantiation. This is because the property is inherited from another instance. The designer defines resetting the property value as setting it to the value that was set by the inherited class. This value may differ from the default value stored in metadata.
The following code example provides an example ComponentDesigner implementation and an example component associated with the designer. The designer implements an override of the Initialize method that calls the base Initialize method, an override of the DoDefaultAction method that displays a MessageBox when the component is double-clicked, and an override of the Verbs property accessor that supplies a custom DesignerVerb menu command to the shortcut menu for the component.
using System; using System.Collections; using System.ComponentModel; using System.ComponentModel.Design; using System.Drawing; using System.Windows.Forms; namespace ExampleComponent { // Provides an example component designer. public class ExampleComponentDesigner : System.ComponentModel.Design.ComponentDesigner { public ExampleComponentDesigner() { } // This method provides an opportunity to perform processing when a designer is initialized. // The component parameter is the component that the designer is associated with. public override void Initialize(System.ComponentModel.IComponent component) { // Always call the base Initialize method in an override of this method. base.Initialize(component); } // This method is invoked when the associated component is double-clicked. public override void DoDefaultAction() { MessageBox.Show("The event handler for the default action was invoked."); } // This method provides designer verbs. public override System.ComponentModel.Design.DesignerVerbCollection Verbs { get { return new DesignerVerbCollection( new DesignerVerb[] { new DesignerVerb("Example Designer Verb Command", new EventHandler(this.onVerb)) } ); } } // Event handling method for the example designer verb private void onVerb(object sender, EventArgs e) { MessageBox.Show("The event handler for the Example Designer Verb Command was invoked."); } } // Provides an example component associated with the example component designer. [DesignerAttribute(typeof(ExampleComponentDesigner), typeof(IDesigner))] public class ExampleComponent : System.ComponentModel.Component { public ExampleComponent() { } } }
Available since 1.1
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe. | https://msdn.microsoft.com/en-us/library/system.componentmodel.design.componentdesigner.aspx | CC-MAIN-2017-39 | en | refinedweb |
Im open to switching the attributes back to camelCase. Thats the more
accepted case for JSON anyway. Remember, nothing is set in stone right now.
A few other points...
I am not too concerned what other projects or products do. DeviceAtlas,
CC/PP, etc. My biggest concern is getting things right for this project.
This means using sound and well practiced logic.
Converting XML to JSON is going to be a handful of lines of scripting code.
Not sure why you are thinking that would be a manual effort.
On Fri, Jul 17, 2015 at 7:45 AM, Werner Keil <werner.keil@gmail.com> wrote:
> Stefan/all,
>
> One good question to ask about a new JSON format are, whether or not to
> abandon the accepted vocabulary or not.
> suggests some breaches,
> e.g. changing "displayWith" or "displayHeight" to "display_width" and
> "display_height" with no real reason other than putting a "_" there.
> Same with "vendor" vs. "manufacturer".
>
> CC/PP which I investigate for offering Portlet 3 Device Profile support
> backed by repositories like DeviceMap does not seem to define a vocabulary
> as extensive as W3C DDR.
> However, shows
> clearly, where the most common attributes like "displayHeight" are used,
> their names are exactly identical to W3C DDR hence matching current
> DeviceMap data. Not surprising, as most attributes and vocabularies are
> based on groups like OMA and its members who gathered them in the past (and
> some still do)
>
> If you're wondering about DeviceAtlas and their "new" JSON file. The actual
> attributes are optimized and names scrambled into weird numeric UUIDs, but
> the mapping to actual atttibute names
>
>
> ["bisBrowser","bisChecker","bisDownloader","bisFilter","bisRobot","bisSpam","bisFeedReader","bmobileDevice","iid","bmarkup.xhtmlMp11","bmarkup.xhtmlMp12","buriSchemeTel","bhttps","imemoryLimitMarkup","imemoryLimitEmbeddedMedia","imemoryLimitDownload","bmidiMonophonic","bmidiPolyphonic","bamr","bmp3","baac","bqcelp","bmpeg4","b3gpp","b3gpp2","bwmv","bh263Type0InVideo","bh263Type3InVideo","bmpeg4InVideo","bamrInVideo","bawbInVideo","baacInVideo","baacLtpInVideo","bqcelpInVideo","bdrmOmaForwardLock","bdrmOmaCombinedDelivery","bdrmOmaSeparateDelivery","bcsd","bhscsd","bgprs","bedge","bhsdpa","bmarkup.xhtmlMp10","bmarkup.xhtmlBasic10","bimage.Gif87","bimage.Gif89a","bimage.Jpg","bimage.Png","bumts","iusableDisplayWidth","iusableDisplayHeight","smidp","scldc","bjsr30","bjsr139","bjsr37","bjsr118","bosSymbian","bosLinux","bosWindows","bosRim","bosOsx","sosProprietary","sosVersion","sdeveloperPlatform","sdeveloperPlatformVersion","buriSchemeSms","buriSchemeSmsTo","iyearReleased","b3gp.h264.level10","b3gp.h264.level10b","b3gp.h264.level11","b3gp.h264.level12","b3gp.h264.level13","
> b3gp.aac.lc
> ","b3gp.h263","b3gp.amr.nb","b3gp.amr.wb","bmp4.h264.level11","bmp4.h264.level13","
> bmp4.aac.lc
> ","bstream.3gp.h264.level10","bstream.3gp.h264.level10b","bstream.3gp.h264.level11","bstream.3gp.h264.level12","bstream.3gp.h264.level13","
> bstream.3gp.aac.lc
> ","bstream.3gp.h263","bstream.3gp.amr.nb","bstream.3gp.amr.wb","bstream.mp4.h264.level11","bstream.mp4.h264.level13","
> bstream.mp4.aac.lc
> ","bmarkup.wml1","bvCardDownload","btouchScreen","boma","bhttpDirectDownload","bosAndroid","svendor","smodel","idisplayWidth","idisplayHeight","idisplayColorDepth","sinputDevices","smarkupSupport","sstylesheetSupport","simageFormatSupport","sinputModeSupport","bcookieSupport","sversion","sscriptSupport"]
>
> shows clearly, their entire vocabulary in their W3C DDR compatible XML
> format is also used by the JSON files. A Hungarian prefix like "i" for int
> or "s" for String is the only difference.
>
> CC/PP just like W3C DDR also makes clear distinction between
> device/hardware, OS/Software or Browser/UA. This has been there ever since,
> the files dedicated to OS or Browser were just not used as intended and the
> only aspect out of 3 or more was "device".
>
> Nobody with a sane mind and busy workload (as almost everyone here has;-)
> would go and manually enter every single device. Even if a "crowd" effort
> or harvesting it from friendly sites was picked up again, they usually
> gather these based on accepted formats and naming schemes. Either you have
> to translate everything or you lose precious information due to a name
> mismatch.
>
> Werner
>
> On Thu, Jul 9, 2015 at 2:24 PM, Werner Keil <werner.keil@gmail.com> wrote:
>
> > Hi Stefan,
> >
> > Thanks for your reply and a fresh view on both data and clients.
> > Note, the "contrib" section while it may not be technically r/o in SVN
> > there is no more active development. It is more or less an "archived"
> > historical view to some of the original contributions.
> > We further modularized clients in recent months, so
> > clients/1.0/java
> > clients/1.0/java_w3c_simple
> > already tell they belong together.
> > One should have a dependency on the other, even if they may not be
> modules
> > using a common Parent POM at the moment (they should but as long as you
> use
> > the right version of "Classifier" for the W3C "Wrapper" it would work)
> >
> > W3C defined a very bulky test suite (e.g. a class with a 20-30 argument
> > constructor;-O) which I started composing under
> > clients/w3c-ddr/simpleddr/src/test/java
> >
> > Test runner is currently a standalone app, but it seems possible to
> > convert it into an actual JUnit tests, though the test harness does a lot
> > of things at once, and previous results of these tests mainly consist of
> > console or HTML-generated results of a standalone app.
> >
> > On GitHub someone earlier compared OpenDDR to other solutions like
> > 52DegreesMobi:
> >
> >
> > It should be possible to run his test at least against the W3C DDR
> > DeviceMap client, too. Would be interesting to see, if data updates
> > improved our results ideally compared to a recent version of other
> products.
> >
> > The 1.0 "Wrapper" I did not try to run against the test harness. It is a
> > partial implementation of the W3C DDR Simple API, so some aspects the
> test
> > expects may not even be there. If all test data is in place for the
> > "classic" W3C DDR client, we could always try both. If an implementation
> > passes all or most of the relevant tests, it may call itself "W3C
> > compliant" against the DDR recommendation.
> >
> > You're more than welcome to help with either client(s) or just contribute
> > to data, whatever you feel most comfortable with.
> > As soon as you got a good enough picture of what's there;-)
> >
> > Werner
> >
> > On Wed, Jul 8, 2015 at 10:27 PM, Stefan Seelmann <
> mail@stefan-seelmann.de>
> > wrote:
> >
> >> Hi Werner,
> >>
> >> many thanks for the detailed explanation.
> >>
> >> I saw BrowserDataSource.xml and OperatingSystemDataSource.xml, but as I
> >> found no "detection" patterns and as the also not loaded by the (Java)
> >> devicemap-client I thought they are not used.
> >>
> >> The project contains lot of pieces, I didn't yet figured out how they
> >> fit together. Initially I just saw and tried the official released Java
> >> device-map client. Now I digged a bit deeper and there are (at least) 4
> >> Java clients in SVN
> >>
> >> clients/1.0/java
> >> clients/1.0/java_w3c_simple
> >> clients/w3c-ddr
> >> contrib/openddr/java
> >>
> >> The one in "clients/w3c-ddr/simpleddr" actually is able to
> >> detect/classify OS and browser including versions. It has lot of
> >> specialized Builders which use regex matching to detect UAs (but e.g.
> >> not Firefox on Windows). Support of an existing W3C API seems noble, but
> >> with its data structructures and namespaces it is a bit cumbersome to
> use.
> >>
> >> On the other hand the one in "clients/1.0/java" just seems to use the
> >> patterns defined in BuilderDataSource.xml, without regex matching. It is
> >> totally simple to use.
> >>
> >> I think it makes sense to define patterns in data files, as different
> >> client implementations can use the same data. Hardcoded parsers are more
> >> difficult to port to other languages/platforms. Regex is quite powerful
> >> but probably slower than simple character matching.
> >>
> >> Sorry for dumping my findings and thoughts. I'm still try to find my way
> >> into the project.
> >>
> >> Kind Regards,
> >> Stefan
> >>
> >>
> >>
> >> On 07/08/2015 10:50 AM, Werner Keil wrote:
> >> > Hello Stefan,
> >> >
> >> > Thanks a lot for your input. You're asking some good and constructive
> >> > questions.
> >> >
> >> > With regards to what devices have a browser, this recent post on the
> >> > DeviceAtlas (clearly the most visible and likely notable commercial
> >> vendor
> >> > in this field) page
> >> >
> >> > It contains devices like XBox or even Samsung Gear, etc.
> >> >
> >> > With regards to dealing with devices and browsers separately, the DDR
> >> > standard and formats has always intended to do so, just look at
> >> >
> >>
>
> >> > but this and other XML files are clearly undervalued and barely used
> >> > especially by the "Classifier" family of clients.
> >> >
> >> > Other clients due to their W3C DDR compliant heritage do, but if the
> >> data
> >> > is not maintained there, neither will get you proper results;-|
> >> >
> >> > You're right, that some of the visions around 2.0 can be promising if
> >> > there's enough support by the community. Neither of us can do this
> >> alone,
> >> > and while some projects like this may be smaller than others, a key
> >> reason
> >> > to donate the codebase of OpenDDR here was to increase the community
> >> where
> >> > possible.
> >> >
> >> > Aside from a service-based approach
> >> >
> >> > DeviceAtlas also makes it pretty clear, their primary format is JSON
> >> now:
> >> >
> >> > while it is safe to assume, other commercial closed-source
> alternatives
> >> > like WURFL still dance around the WURFL.xml even if they may have
> >> stored it
> >> > into some XML DB now, too;-)
> >> >
> >> > An important effort is, to transform existing device information (our
> >> crown
> >> > jewel after all;-) from XML to JSON once the new format or formats are
> >> > defined and agreed on. Whether or not there's also a 2-way conversion,
> >> we
> >> > shall see.
> >> > You can be sure, commercial closed-source vendors like DeviceAtlas
> offer
> >> > this but it's up to the community if we can and want to offer that as
> >> well.
> >> >
> >> > Contributing e.g. via JIRA or (I think you may also self-register for
> >> that)
> >> > the Wiki would be a good start. If you have concrete patches or code
> >> > contributions, attaching them (as patch, diff or "snippet") to a JIRA
> >> > ticket is a good practice to start helping. For some this lead to
> >> becoming
> >> > a full committer, so we'd welcome others to do so if they help on a
> >> regular
> >> > basis.
> >> >
> >> > Thanks and Regards,
> >> >
> >> > Werner
> >> >
> >> > On Wed, Jul 8, 2015 at 12:24 AM, Stefan Seelmann <
> >> mail@stefan-seelmann.de>
> >> > wrote:
> >> >
> >> >> Hello,
> >> >>
> >> >> I have the need to classify not only mobile devices, but also desktop
> >> >> browsers and other clients (e.g. email clients) including operating
> >> >> system and versions. The current state of DeviceMap seems not
> suitable
> >> >> for this, for example Firefox and Chrome are just classifed as
> >> >> "desktopDevice".
> >> >>
> >> >> I already tried to add patterns to BuilderDataSourcePatch.xml and
> >> >> DeviceDataSourcePatch.xml. That somehow worked, but if I understand
> the
> >> >> data format correctlry I'd have to create one "device" per
> >> >> OS+version/browser+version, which would result in an insane number
of
> >> >> combinations.
> >> >>
> >> >> Is there a better way to define data using the version 1 device data
> >> >> format to achive my needs?
> >> >>
> >> >>
> >> >> I also browsed the wiki and mailing list archive. The "Device Data
> 2.0"
> >> >> specification looks very promising to me. There seem to be neither
> code
> >> >> nor data (not even prototypes) available. Based on mailing list
> archive
> >> >> I'm even not sure if there is consensus among the developers go for
> >> this
> >> >> new data format.
> >> >>
> >> >> Are there plans within the community to develop the version 2?
> >> >>
> >> >> How can I help (with limited resources...)?
> >> >>
> >> >>
> >> >> Kind Regards,
> >> >> Stefan
> >> >>
> >> >
> >>
> >>
> >
> | http://mail-archives.apache.org/mod_mbox/devicemap-dev/201507.mbox/%3CCAKuYhJvc8wdNZF6Mb6OgWJX=YX=YVb=MnGbcQ1c0TRY7b2DWxg@mail.gmail.com%3E | CC-MAIN-2017-39 | en | refinedweb |
Working with the Amazon Maps API on the Kindle Fire
<google>BUY_KINDLE_FIRE</google>
One can argue with a reasonable degree of certainty that Google has created one of the best and most accurate digital map services available on the market today. In the early versions of iOS, Apple made the wise decision to rely on Google Maps for navigation on the iPhone. Rather than continue to use Google Maps, however, Apple instead invested a considerable amount of effort in developing a replacement to Google Maps in iOS 6. The result was an unreliable service that became a public relations problem for Apple and resulted in the departure of a number of senior Apple executives.
When a mobile device manufacturer chooses to use Android as the operating system for a new device, Google Maps comes bundled as part of the overall package. The typical Android based phone or tablet, therefore, includes a Google Maps application and provides access to the Google Maps API for use by app developers. This, however, is not the case for the Kindle Fire. Amazon has, instead, removed Google Maps from both the operating system and the SDK, and replaced it with the Amazon Maps system.
This aversion to using the Google Maps system on the part of Apple and Amazon is not entirely irrational. Consider, for example, that the provider of the map service on a mobile device gets to learn a great deal of information about a user. Each time a user accesses the map system, the provider finds out not only where the user is, but also where they might be going. Understandably, neither Apple nor Amazon were comfortable letting Google (in many ways a competitor) have this level of information about their customers.
This chapter is intended to provide an overview of the Amazon Maps system and API. Once the basics have been covered, the following chapters will work through some tutorials demonstrating the use of this API.
Amazon Maps vs. Google Maps
When Amazon took the decision not to use Google Maps on the Kindle Fire it became evident that this might present a problem for the large number of existing Android applications that would potentially need to be migrated to the Kindle Fire. In recognition of this fact, the Amazon Maps API largely mirrors that of Google Maps. Most existing Google Maps code will, therefore, migrate over to Amazon Maps without requiring a significant amount of work.
One key issue, however, is that Amazon Maps lacks some of the main features of Google Maps, street views and traffic information being two notable examples. Whilst the Amazon Maps API includes these API features so that existing code will compile, they do nothing when called by the application.
The Elements of Amazon Maps
The Amazon Maps API consists of a core set of classes that combine to provide mapping capabilities in Android applications on the Kindle Fire. The key classes are:
- MapActivity – A subclass of the Android Activity class, this provides the base class for activities that need to provide map support. Any activity that needs to work with maps must be derived from this class.
- MapView - Provides the canvas onto which the map is drawn.
- MapController – Provides an interface for managing an existing map. This class includes capabilities such as setting both the center coordinates of the map and the current zoom level.
- ItemizedOverlay – A class specifically designed to overlay information onto a map. For example, an overlay might be used to mark all the locations of the public libraries in a town. A single overlay can contain multiple items, each represented by an OverlayItem instance. An onTap() callback method may be implemented to pop up additional information about a location when tapped by the user.
- OverlayItem – Used to represent each item in an ItemizedOverlay. Each item has associated with it a location on the map and an optional image to mark the location.
- MyLocationOverlay – A special-purpose overlay designed specifically to display the current location of the device on the map view.
- Overlay – A general-purpose overlay class provided primarily to allow transparent effects or content to be placed on top of the map.
Getting Ready to Use Amazon Maps
The use of Amazon Maps in an application is somewhat unusual since there is more work involved in setting up the environment than there is in actually writing the Java code. Each step must be performed carefully to ensure that maps will function within an application.
Downloading the Amazon Mobile SDK
Amazon Maps are part of the Amazon Mobile SDK, which will need to be downloaded and integrated into any Eclipse project for which maps are to be included. The SDK can be downloaded using the following link:
Once downloaded, unzip the archive into a suitable location.
Adding the Amazon Mobile SDK to an Eclipse Project
The Maps SDK JAR file will need to be added to the build path of any application that requires map functionality. To add map support to a project, locate it <sdk path> is replaced by the location on your file system where the Amazon Mobile SDK was installed in the previous step):
as illustrated in Figure 40-1:
Figure 40-1
Assuming the JAR file is now listed, click on OK to close the Properties dialog.
Obtaining Your Developer Signature
Before an application can make use of the Amazon Maps API, it must first be registered in the Amazon Mobile App Distribution portal. Before an app can be registered, however, the developer signature (also referred to as the MD5 debug fingerprint) associated with your development environment must be obtained. This is achieved by running the keytool utility that is supplied in the bin directory of the Java Development Kit (JDK) installed on the development system as outlined in Setting up a Kindle Fire Android Development Environment. One of the arguments passed to the keytool utility is the path to a file named debug.keystore. To find the location of this file, select the Eclipse Windows -> Preferences menu option and in the resulting dialog select Android -> Build from the left hand panel. In the Build Settings panel, the location of the file can be found in the Default debug keystore: field. Once the location has been identified, execute the following command within a terminal or command prompt window (where <key path> is replaced by the path to the debug.keystore file):
keytool -v -list -alias androiddebugkey -keystore <key path> -storepass android
Upon execution, the above command will generate output similar to the following example:
Alias name: androiddebugkey Creation date: Nov 30, 2011 Entry type: PrivateKeyEntry Certificate chain length: 1 Certificate[1]: Owner: CN=Android Debug, O=Android, C=US Issuer: CN=Android Debug, O=Android, C=US Serial number: 503f6f0b Valid from: Wed Nov 30 13:26:24 EST 2011 until: Fri Nov 22 13:26:24 EST 2041 Certificate fingerprints: MD5: DF:86:AB:19:DC:28:BF:62:4C:49:82:6E:BA:77:45:B4 SHA1: 6F:AD:25:3F:90:56:6C:9B:7D:29:95:54:AF:E3:E0:29:64:DB:BD:22 SHA256: B8:3B:C7:43:4A:0A:77:E6:38:E1:66:18:E4:FF:EE:AA:55:66:88:99:F6: 6B:16:11:4D:E9:DA:DD:4E:0F:D0:B8 Signature algorithm name: SHA256withRSA Version: 3
The MD5 fingerprint is the sequence of hexadecimal number pairs on the MD5: line of the output.
Registering the Application in the Amazon Mobile App Distribution Portal
The next step is to register the application in the Amazon distribution portal and input the MD5 debug fingerprint to enable Map support. To achieve this, open a web browser and navigate to the following URL:
On the welcome page, click on the Sign In link in the top right hand corner of the page and enter your login credentials. If you do not yet have a developer account, click on the Create an Account button to create one now.
Once logged in, click on the Add a New App button located within the dashboard panel as shown in Figure 40-2:
Figure 40-2 and then cut and paste the MD5 fingerprint into the Developer Signature field before clicking on the Submit button.
At this point, the development environment is set up to enable Maps to be used within a specific application. The next step is to set up the application itself to use maps. This begins with making some additions to the application’s Android manifest file.
Adding Map Support to the AndroidManifest.xml File
Before maps can be used in an application, an additional entry needs to be added to the application’s Android Manifest file. Within Eclipse, locate the manifest file for the project for which the Maps JAR file was added to the build path and load the AndroidManifest.xml file into the editing panel. The line that needs to be added reads as follows:
xmlns:amazon=""
This directive needs to be added as part of the existing <manifest> element. For example:
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns: . .
In addition, the Amazon Maps API requires that a number of permissions be requested within the manifest file:
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns: <uses-permission android: <uses-permission android: <uses-permission android: . .
Finally, the application element of the Manifest file must include the following tag:
<amazon:enable-feature android:
For example:
. . . <application android: <amazon:enable-feature android: <activity android: . . .
Enabling Location Based Services on the Kindle Fire Device
By default, Kindle Fire devices are shipped with location based services disabled. Before testing a map-based application on a physical device, therefore, this feature must first be enabled. To do this, display the settings app on the device (via a downward swipe from the top edge of the screen). Select the More option followed by Location Based Services. Within the location settings screen (Figure 40 3) change the Enable location-based Services setting from Off to On.
Figure 40-3
Registering an Emulator
When using an AVD Kindle Fire emulator to test maps within an application, that emulator must be registered with Amazon. An attempt to access maps on an unregistered emulator will result in the application crashing. To register an emulator, start it running and display the settings app (on an emulator this is displayed by clicking at the top of the device display and dragging the mouse to the bottom of the screen). Select More followed by My Account.
On the My Account screen, click on the Register button and enter the login and password details associated with your Amazon.com account. Once the information has been entered, click on Register and wait for the process to complete. The emulator should now support use of the Amazon Maps API.
Adjusting the Emulator Location Settings
When testing an application in the emulator, the location will be set using IP information from the internet connection of the computer system on which the emulator is running. Different locations can be simulated using the Debug Perspective within Eclipse. This can be displayed by selecting the Window -> Show Perspective -> DDMS option. When the DDMS perspective appears, select the Emulator Control tab in the main panel. At the bottom of the panel is a section named Location Controls where new Longitude and Latitude values may be entered.
Having covered the steps involved in enabling maps support in Kindle Fire applications, the remainder of this chapter will provide an overview of how map functionality may be implemented within an application.
Checking for Map Support
All Kindle Fire devices with the exception of the first generation Kindle Fire support the Amazon maps runtime library. This means that any application that intends to use the Maps API must check whether the device on which it is running supports the maps feature before attempting to make any Maps API calls. The recommended way to perform this task is to check for the presence or otherwise of the maps runtime. The following method can be included in applications and subsequently called to check whether maps are supported:
public boolean hasMapSupport() { boolean result = false; try { Class.forName( "com.amazon.geo.maps.MapView" ); result = true ; } catch (Exception e) {} return result; }
When called, the method will return a true value if maps are supported on the device and false if not.
Understanding Geocoding and Reverse Geocoding
It is impossible to talk about maps and geographical locations without first covering the subject of Geocoding. Geocoding can best be described as the process of converting a textual based geographical location (such as a street address) into geographical coordinates expressed in terms of longitude and latitude.
Geocoding can be achieved using the Android Geocoder class. An instance of the Geocoder class can, for example, be passed a string representing a location such as a city name, street address or airport code. The Geocoder will attempt to find a match for the location and return a list of Address objects that potentially match the location string, ranked in order with the closest match at position 0 in the list. A variety of information can then be extracted from the Address objects, including the longitude and latitude of the potential matches.
The following code, for example, requests the location of the National Air and Space Museum in Washington, D.C.:
double latitude; double longitude; List<Address> geocodeMatches = null; geocodeMatches = new Geocoder(this).getFromLocationName("600 Independence Ave SW, Washington, DC 20560", 1); if (!geocodeMatches.isEmpty()) { latitude = geocodeMatches.get(0).getLatitude(); longitude = geocodeMatches.get(0).getLongitude(); }
Note that the value of 1 is passed through as the second argument to the getFromLocationName() method. This simply tells the Geocoder to return only one result in the array. Given the specific nature of the address provided, there should only be one potential match. For more vague location names, however, it may be necessary to request more potential matches and allow the user to choose the correct one. The above code is an example of forward-geocoding in that coordinates are calculating based on a text location description. Reverse-geocoding, as the name suggests, involves the translation of geographical coordinates into a human readable address string. Consider, for example, the following code:
List<Address> geocodeMatches = null; String Address1; String Address2; String State; String Zipcode; String Country; geocodeMatches = new Geocoder(this).getFromLocation(38.8874245, -77.0200729, 1); if (!geocodeMatches.isEmpty()) { Address1 = geocodeMatches.get(0).getAddressLine(0); Address2 = geocodeMatches.get(0).getAddressLine(1); State = geocodeMatches.get(0).getAdminArea(); Zipcode = geocodeMatches.get(0).getPostalCode(); Country = geocodeMatches.get(0).getCountryName(); }
In this case the Geocoder object is initialized with latitude and longitude values via the getFromLocation() method. Once again, only a single matching result is requested. The text based address information is then extracted from the resulting Address object. It should be noted that the geocoding is not actually performed on the Kindle Fire device, but rather on a server to which the device connects when a translation is required and the results subsequently returned when the translation is complete. As such, geocoding can only take place when the Kindle Fire has an active internet connection.
Adding a MapView to an Application
The simplest way to add a MapView to the application is to specify it in the user interface layout XML file for an activity. The following example layout file shows a MapView instance added as the child of a RelativeLayout view:
<RelativeLayout xmlns: <com.amazon.geo.maps.MapView android: </RelativeLayout>
Next, the activity with which the layout file is associated must be derived from the MapActivity class, instead of the Activity class. Failure to follow this rule will result in the application crashing when the map is invoked. The following code, for example, shows the activity implementation for the above layout:
public class MapViewActivity extends MapActivity { private static MapView mapView; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_map_view); mapView = (MapView) findViewById(R.id.mapview); } . . }
When executed, the above code would create and display a map, which, by default, will show the entire world. The user will be able to interact with the map, panning using swipes and zooming in and out using pinch gestures. In addition, a set of built-in zoom controls can be enabled on the map view via a call to the setBuiltInZoomControls() method of the MapView object:
mapView.setBuiltInZoomControls(true);
Once enabled, the controls will appear for a brief period of time when the map first appears. Subsequent taps on the map view will re-display the controls for a limited time before they again recede from view.
Customizing a Map View using the MapController
Each MapView instance has associated with it a MapController object. A reference to this controller can be obtained via a call to the getController() method of the corresponding MapView instance. Once this reference has been obtained, a variety of methods may be called on the controller to perform tasks such as setting the zoom level and center point of the map, animating zoom effects and scrolling by specified numbers of pixels.
The following code sets the zoom level (which must be an integer between 1 and 21 inclusive) to 18 before setting the center of the map view to a specific set of coordinates:
MapControler mapController = mapView.getController(); GeoPoint newLocation = new GeoPoint((int)(address.getLatitude() * 1E6), (int)(address.getLongitude() *1E6)); mapController.setZoom(18); mapController.setCenter(newLocation);
When setting the center of the map, the location needs to be provided in the form of a GeoPoint object which can be created by specifying the longitude and latitude as microdegrees (equivalent to degrees * 1E6).
Displaying the User’s Current Location
The user’s current location can be marked on the map view by making use of the MyLocationOverlay class. This is achieved by enabling access to the user’s current location, getting a list of the current overlays assigned to the map view, creating a new MyLocationOverlay object and adding it to the overlay list.
If the map is not currently displaying an area that includes the user’s current location, the location marker will not be visible on the map. The center of the map, however, can be changed to match the current location as demonstrated in the following code fragment:
myLocationOverlay = new MyLocationOverlay(this, mapView); mapView.getOverlays().add(myLocationOverlay); myLocationOverlay.enableMyLocation(); GeoPoint myLocation = myLocationOverlay.getMyLocation(); mapController.setCenter(myLocation); mapController.setZoom(18);
When executed, the map will center on the user’s current location and display a marker at that point on the map.
Creating an Itemized Overlay
The purpose of the itemized overlay is to allow multiple locations to be marked on a map view. The steps involved in working with itemized overlays will be covered in detail in the chapter entitled Marking Android Map Locations using Amazon Map Overlays, but can be summarized as follows:
1. A new class needs to be created that subclasses the ItemizedOverlay<OverlayItem> class.
2. A set of required methods must be implemented in the class created in step 1.
3. An instance of the new ItemizedOverlay subclass is created in the map activity class and initialized with the drawable image that is to be used as the location marker.
4. An OverlayItem object is created for each location on the map for which a marker is required to be displayed. Each object is initialized with the location at which the marker is to appear together with optional text that may be displayed when the location is tapped by the user.
5. Each OverlayItem object created in step 4 is added to the ItemizedOverlay instance created in step 3.
6. The ItemizedOverlay instance is added to the map view overlays.
Summary
Along with the introduction of location awareness in the more recent Kindle Fire generations came the Amazon Maps API. This API is intended to be compatible with the Google Maps API and allows mapping capabilities to be built into Kindle Fire based Android applications.
This chapter has provided an overview of the key classes that make up the Amazon Maps API and outlined the steps involved in preparing both the development environment and an application project to make use of the Amazon Maps API.
<google>BUY_KINDLE_FIRE</google> | http://www.techotopia.com/index.php/Working_with_the_Amazon_Maps_API_on_the_Kindle_Fire | CC-MAIN-2017-39 | en | refinedweb |
Writing Tests for a Stored Proc Sure Feels Weird
Some times you are just stuck and have to write some weird test fixtures to get the level of confidence you need to move forward in a legacy system. You can’t simply throw the baby out with the bath water no matter how much you really, really want every one to agree that is the best course of action.
In that situation, it is just as important to stick to your guns and find a way to wrap a test around what you are working on. Case in point, the current project I am on is your traditional business logic in sprocs application. By mandate, all updates to data must happen in a sproc so that business rules can be “enforced”.
The team of developers I have joined have no faith in Agile practices and see unit testing as a drain on their time and resources for no value. Interestingly enough, when I joined the team the vast majority of sprint items were bug fixes to multi-hundred line sprocs where the fix might actually cause more bugs. There was no real way to gain any kind of confidence other than poking the application with a stick.
Enter the stored procedure unit test fixture.
[TestFixture] public class when_creating_a_new_research_item_and_an_open_research_item_already_exists : with_a_valid_security { private Execute statement; public override void Because_of() { statement = Execute.Proceedure("spResearchItem_Create") .WithParameter("@TableName", tableName) .WithParameter("@ColumnName", columnName) .WithParameter("@AssignedToUser", user) .WithParameter("@ItemId", recordId) .WithParameter("@Note", note); } [Test] public void it_should_refuse_to_create_the_record() { Assert.Throws(() => { statement.AsNonQuery(); }); } [Test] public void it_should_have_a_descriptive_error() { var error = Assert.Throws(() => { statement.AsNonQuery(); }); error.Message.ShouldContain("Open Research Item Already Exists"); } [Test] public void no_record_should_be_created() { var count = Execute.Statement( @"SELECT COUNT(*) FROM ResearchItem WHERE [email protected] AND [email protected] AND [email protected] AND IsOpen='Y'") .WithParameter("@p1", tableName) .WithParameter("@p2", columnName) .WithParameter("@p3", recordId) .AsValue(); count.ShouldBe(1); } }
This single fixture explicitly demonstrates a business rule, it can run with every build and we will get instant notification when this rule can be violated because of changes in the sproc. It is also nicely wrapped in a transaction that is automatically rolled back, so I can point it at any database and test its set of sprocs. It is not optimal, it is not pretty. But it does give you confidence to move forward.
Side Note: Don’t pay to much attention to the Execute class. It is simply a test helper to remove some of the tediousness of executing ADO code from the tests.
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About Author
I am a passionate engineer with an interest in shipping quality software, building strong collaborative teams and continuous improvement of my skills, team and the product. | https://iamnotmyself.com/2010/04/02/writing-tests-for-a-stored-proc-sure-feels-weird/ | CC-MAIN-2017-39 | en | refinedweb |
FSTAT(3P) POSIX Programmer's Manual FSTAT(3P)
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
fstat — get file status
#include <sys/stat.h> int fstat(int fildes, struct stat *buf);‐2008,‐2008, Section 4.8, File Times Update), before writing into the stat structure.
Upon successful completion, 0 shall be returned. Otherwise, −1 shall be returned and errno set to indicate the error.);
None.
None.
None.
fstatat(3p) The Base Definitions volume of POSIX.1‐2008, Section 4.8, File Times Update, sys_stat.h(0p), sys FSTAT(3P)
Pages that refer to this page: sys_stat.h(0p), fstatat(3p), posix_typed_mem_get_info(3p), posix_typed_mem_open(3p), utime(3p) | http://man7.org/linux/man-pages/man3/fstat.3p.html | CC-MAIN-2017-39 | en | refinedweb |
Version 0.4.0.428 of DBTestUnit has been released and can be downloaded from SourceForge.
This release implements the name change from ‘Database testing framework’ to ‘DBTestUnit’.
So what has changed?
There has been no change in overall functionality.
Basically, a number of components and namespaces have been changed to reflect the new name.
These include:
- DatabaseTesting.dll renamed to DBTestUnit.dll.
The test dll is now found in: …\Projects\DBTemplate\libs\DBTestUnit\
- DatabaseTesting.ExportDBDataAsXML.exe renamed to DBTestUnit.ExportDBDataAsXML.exe.
The exe is found in: …\DBTemplate\tools\ExportDBDataAsXML\
- All sample tests have been updated to reference DBTestUnit.dll rather than DatabaseTesting.dll
- All namespaces have been updated
eg
using DatabaseTesting.UnitTestBaseClass.MSSQL;
to d
using DBTestUnit.UnitTestBaseClass.MSSQL;
How does this effect using the framework?
If you are a new user – none. Just download and start using.
If you are using a previous version – there are a number of relatively minor steps that you will need to carry out if you want to start using the new ‘renamed’ version.
1. Download the latest version – eg 0.4.0.428_DBTestUnit.zip
2. In your database testing solution remove all references to the ‘old’ DatabaseTest.dll.
3. Add a reference to the new test dll – DBTestUnit.dll – found in ….\Projects\DBTemplate\libs\DBTestUnit\.
4. Update any existing namespaces to reflect the new name ie do a ‘find and replace’ changing ‘DatabaseTest’ to ‘DBTestUnit’.
eg
using DatabaseTesting.InfoSchema; using DatabaseTesting.UnitTestBaseClass.MSSQL;
to
using DBTestUnit.InfoSchema; using DBTestUnit.UnitTestBaseClass.MSSQL;
5. Next you will need to change the test dll config file.
In the sample project provided – which uses AdventureWorks database as an example – then the change would be applied to following config file:
…\src\AdventureWorksDatabaseTest\bin\Debug\
AdventureWorks.DatabaseTest.dll.config
The following change would be made to reflect the changes in the internal namespaces of the testing framework.
<!--************************************--> <add key="AssemblyName" value="DatabaseTesting"></add> <add key="DaoFactoryNamespace" value="DatabaseTesting.InfoSchema.DataAccess.MSSQL"></add>
to
<!--************************************--> <add key="AssemblyName" value="DBTestUnit"></add> <add key="DaoFactoryNamespace" value="DBTestUnit.InfoSchema.DataAccess.MSSQL"></add>
6. The final part is if you use the XML export tool found in:
…\DBTemplate\tools\ExportDBDataAsXML\
For this, it is probably easier to just take a copy of the latest version of this from the download.
Make sure that you take a back up of your existing config files as you will need to incorporate them into the ‘vanilla’ config files from the new download.
And that’s it.
If you have any problems ‘upgrading’ feel free to contact me. | https://dbtestunit.wordpress.com/2011/02/25/version-0-4-0-428-dbtestunit-released/ | CC-MAIN-2017-39 | en | refinedweb |
Screen scraping
Most of the interesting servers in the world are web servers. While the layout of the web pages is in HTML that a machine can handle (with some effort), the essential data in that file is meant for human to read and is rarely designed to be easily extracted by software. But there are ways.
I considered using OpenEye's demo site and PubChem as possible examples but they proved to be too complex for this esssay. After some searching I came across a program at NIST that allows searching for compounds based on molecular weight.
For the first version of this code I'll only support searching for a given atomic weight +/- 0.5 amu. I want the interface to look like this:
>>> results = mw_search(145) >>> len(results) 118 >>> results[0] (144.86, 'AsCl2', 'AsCl2') >>>That is, I give it a value and it returns a list of the hits. Each hit is a 3-tuple of the weight (as a float), the simple name for normal ASCII and the name for HTML.
The HTTP protocol used for the web supports many different request types. Most of them are GET requests and some are POST requests. The easiest way to identify a GET request is to look at the URL for a search page. If it's "complex" (has a '?' followed by additional text) then it's probably a GET request. One test is to bookmark the page, leave, then come back to the bookmark. If the results are unchanged then it's a GET request. Another way to find out is to look at the HTML of the page that starts the search. If it is "<input type="POST" ...>" then it's a POST. If not specified then it's a GET request.
When I tried the search through a web page the results page had the URL:? Value=145&VType=MW&Formula=&AllowExtra=on&Units=SII split it over two lines to make it shorter for the screen.
This is almost certainly a GET request. To test it I changed the "145" which was my MW search criterion to "146". The new results page changed accordingly. GET searches are easier to handle because you can see everything on the URL line. For POST requests you need to look at the HTML, and/or using a debugging proxy, or network sniffer, or perhaps these days a Firefox extension.
Trying to figure out how something works is called reverse engineering. In this case it's pretty simple. The parameters are pretty easily matched to the inputs on the main page:
- Value = the atomic weight
- VType = "MW" (this is a hidden field in the HTML, fixed to be "MW")
- Formula = the optional formula for restricting the search
- AllowExtra = "on" if more element types are allowed than given in the formula
- Units = "SI" for SI units, "CAL" for calories
Python has several libraries for working with the web. There are libraries for the different protocols (HTTP, FTP) and a library on top of that for working with URLs. Actually there are two; urllib and urllib2. I'll use the second which is meant as a replacement for some of the shortcomings of the first. In the following I'll give it the known good URL. It returns with a file-like object. I'll read the full response and display the first 200 characters.
>>> f = urllib.urlopen("?" ... "Value=145&VType=MW&Formula=&AllowExtra=on&Units=SI") >>> s = f.read() >>> print s[:200] <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "DTD/xhtml1-transitional.dtd"> <html xmlns="" xml: <head> <title>Search Result >>>The data I want starts further on down
>>> print s[1700:2200] following will be displayed: </p> <ul> <li>Molecular weight</li> <li>Chemical name</li> <li>Chemical formula</li> </ul> <p> Click on the name to see more data. </p> 1 >>>I just need to make my function create the right URL query string. That's a simple string substitution:
import urllib2 _weight_query = ("?" "Value=%f&VType=MW&Formula=&AllowExtra=on&Units=SI") # ^^ the weight goes here def mw_search(weight): query = _weight_query % (weight,) return urllib2.urlopen(query) print mw_search(145).read()I can run this and see the raw HTML printed to the screen.
After looking at the HTML for a bit I see that the lines I want always start with "<li><strong>". If I assume the format never changes I can use a pretty simple parser to get the fields I want. Here it is
import urllib2 _weight_query = ("?" "Value=%f&VType=MW&Formula=&AllowExtra=on&Units=SI") # ^^ the weight goes here def _extract_data(infile): results = [] for line in infile: if not line.startswith("<li><strong>"): continue # These lines contain the data I want # The weight is between the ';' and the '<' # <li><strong> 144.86 </strong> weight_start = line.index(";")+1 weight_end = line.index("<", weight_start) weight = float(line[weight_start:weight_end]) # The chemical name is between the 'SI">' and the next '<' # SI">AsCl2</a> name_start = line.index('SI">')+4 name_end = line.index('<', name_start) name = line[name_start:name_end] # The chemical formula (in HTML) is between the parens formula_start = line.index("(", name_end) + 1 formula_end = line.index(")", formula_start) formula = line[formula_start:formula_end] results.append( (weight, name, formula) ) return results def mw_search(weight): query = _weight_query % (weight,) f = urllib2.urlopen(query) return _extract_data(f) if __name__ == "__main__": results = mw_search(145) print results[0] print len(results)Not a very elegant parser but it works. Here's the output
(144.86000000000001, 'AsCl2', 'AsCl<sub>2</sub>') 118
This process of extracting data from the HTML is called screen scraping because it's scraping the data off the screen instead of getting the data more directly. The basic process is exactly like this example: construct a request, parse the response. Though in more complicated cases it may need to make several iterations before it gets the needed results.
Parsing the HTML is often the trickest part of the problem. The HTML returned from the server is ill-defined and often not even valid. Even when valid, there's nothing to define which elements are where or how to identify the data to be extracted. That needs to be figured out by inspection combined with experience.
One helpful library for HTML screen scraping is BeautifulSoup. It tries to convert even poor quality HTML into a tree structure that's easier to parse than working with the HTML as a string.
It does require knowing about the document structure as a tree instead of a set of lines. In this case it looks like the chemical information is in the li fields of the only ol in the record.
>>> f = urllib.urlopen("?" ... "Value=145&VType=MW&Formula=&AllowExtra=on&Units=SI") >>> s = f.read() >>> import BeautifulSoup >>> soup = BeautifulSoup.BeautifulSoup(s) >>> ol = soup.first("ol") >>> ol.first("li") <li><strong> 144.86 </strong> <a href="/cgi/cbook.cgi?ID=C41996376&Units=SI">AsCl2</a> (AsCl<sub>2</sub>)</li> >>>With some experimentation and testing here's the BeautifulSoup version of the parser
import BeautifulSoup import urllib2 _weight_query = ("?" "Value=%f&VType=MW&Formula=&AllowExtra=on&Units=SI") # ^^ the weight goes here def _extract_data def mw_search(weight): query = _weight_query % (weight,) f = urllib2.urlopen(query) soup = BeautifulSoup.BeautifulSoup(f.read()) return _extract_data(soup) if __name__ == "__main__": results = mw_search(145) print results[0] print len(results)
For this case it's only a bit clearer than the original line-oriented parser, mostly because I chose a server that was easy to parse and haven't tried to deal with errors. So let's do that.
What does the server do if I pass it a value that's negative? Trying it interactively I get the page:
No Matching Species Found
No species with the requested data and a molecular weight in the range of [-145.50, -144.50] were found in the database.
and using the function above I get an empty list. That's what I wanted.
Okay, what if there's only one match? I found that searching for a mw=2011 returns
In14P13 anion
- Formula: In14P13-
- Molecular Weight: 2010.11
- CAS Registry Number: 243867-98-3
followed by some additional information. It looks like when there's only one compound then the server shows more data and in different format. The relevant HTML for the parsing is
<h1><a id="Top" name="Top">In14P13 anion</a></h1> <ul> <li><strong>Formula:</strong> In<sub>14</sub>P<sub>13</sub><sup>-</sup></li> <li><strong>Molecular Weight:</strong> 2010.11</li>I can write a parser for this case, I just need to know when to use which one. After looking at the HTML for a bit, if the h1 field has an a in it then it's the detailed information for a single compound. Otherwise it's a list of results or an error message saying there were no results in that range. Not the most satisfying of solutions but that's typical when screen scraping.
The following code implements that logic. Notice how I have one function to identify the contents of the soup then I pass it off to the appropriate parser to extract the right data. This partitioning makes the code easier to read and test.
import BeautifulSoup import urllib2 _weight_query = ("?" "Value=%f&VType=MW&Formula=&AllowExtra=on&Units=SI") # ^^ the weight goes here ## Parses the following # 166899805&Units=SI">Al3S2 anion</a> (Al<sub>3</sub>S<sub>2</sub><sup>-</sup>)</li> def _extract_search_results ## Parses the following # <h1><a id="Top" name="Top">In14P13 anion</a></h1> # <ul> # <li><strong>Formula:</strong> In<sub>14</sub>P<sub>13</sub><sup>-</sup></li> # <li><strong>Molecular Weight:</strong> 2010.11</li> # <li><strong>CAS Registry Number:</strong> 243867-98-3</li> def _extract_single_result(soup): name = soup.first("h1").first("a").string lis = soup.first("ul").fetch("li") # It's the text between the space and the </li> s = str(lis[0]) formula_start = s.index(" ")+1 formula_end = s.index("</li>") formula = s[formula_start:formula_end] weight = float(lis[1].contents[1].string) return [(weight, name, formula)] def _extract_data(soup): h1 = soup.first("h1") # If there's an 'a' tag in the 'h1' then it's # a single element result if h1.first("a") is not BeautifulSoup.Null: return _extract_single_result(soup) else: return _extract_search_results(soup) def mw_search(weight): query = _weight_query % (weight,) f = urllib2.urlopen(query) soup = BeautifulSoup.BeautifulSoup(f.read()) return _extract_data(soup)
There's more that can be done. The function call could be expanded to support more of the server search parameters. The parser for the list results page could include the links to the detailed information about each compound. The information it returns should include a flag if the search limit was reached. The parser for the compound details could extract more of the available details on the page; the image for the structure, 2D mol file, CAS number, alternate names, and so on.
The overall process for developing a client to a web service is similar to the one earlier for interfacing with a subprocess wrapped executable. First, figure out how you want to interact with the system, balancing your expectations with feasability. The data model you come up with might not match that on the server: you can partition overloaded server functions into different API functions, or make one object that merges multiple server requests.
Code the basic functionality. When that works, figure out how to make the server fail in strange ways. Be creative. Remember to put those tests into a automatic testing system. After you rewrite or clean up some code, run the tests. When they pass you know your changes didn't introduce new problems or skip known old problems.
Expand, test, inspect, break, fix. Repeat until you have what you need, bearing in mind that you don't need to implement features you aren't going to need or test for failures that aren't going to happen.
By the way, if you are going to construct more complicated URL query strings, make sure you use use the urllib.urlencode() function. In this essay the only user-defined parameter was a number which is easy to handle using a %f. In most other cases a parameter field may contain arbitrary characters. The rules for URLs put restrictions on which characters are allowed in the URL proper. Any other character must be escaped according to those rules, which urlencode does for you.
| http://dalkescientific.com/writings/diary/archive/2005/04/21/screen_scraping.html | crawl-002 | en | refinedweb |
Ariel is a research project to investigate the design of user interfaces that go beyond the standard mouse and keyboard input modalities. It aims to take advantage of natural means of communication such as speech, gestures, and facial expressions. The challenge is to understand the properties of these new modalities and to uncover the appropriate interface elements to use with them.
Under any of the current window systems, a set of standard elements are used for building a user interface. This includes items like buttons, menus, scrollbars, and dialog boxes. These items have been stable for many years with a few changes like adding hyper-links and image-maps as new basic elements that most user understand. There are also a number of concepts common to these interfaces. Things like "cut and paste" and "drag and drop".
Many people are attempting to take these same elements and implement them using spoken language systems. Ideas like "speakable links" where the user can say the words of a hyperlink instead of clicking on it, or voice menus where the user can speak the items in a traditional menu instead of using the mouse in the typical fashion, are the standard approach to this problem. These interfaces lead to praise such as that found in a recent Time Magazine review of IBM's latest VoiceType software.
"During our demo the system was impressive, though not yet easier than using a mouse." Time, May 13, 1996
I feel that the great lesson to be drawn from all this is that speech recognition makes a lousy mouse. Speech (and the other elements of language based interfaces) differs from mice and keyboards in at least two fundamental ways. First, these interfaces are inherently noisy. It is almost never possible to guarantee any behavior of such a system with less than a 5% error rate. Second, these systems are extremely expressive. Humans have been using gestures and language to communicate with each other. These differing requirements insist that a new set of basic interface elements be discovered.
Ariel is a project to discover these primitives by building a prototype system and working with it every day. The thoroughly overused personal information management task was chosen because of its reasonable size and complexity, as well as the fact that almost everyone uses some version of such a system every day.
The project is currently 4 months old. It consists of minimal e-mail and web browsing capabilities. The basic user interface elements at the moment are the same ones as are found in other similar systems. (Well, you have to start somewhere).
Building a system for research into user interfaces has given me the opportunity to investigate the great variety of graphical modules available for python. I currently have python binaries installed with the following GUI's.
Almost all of these systems (with the exception of OpenGL) make it fairly easy to create a standard GUI under python. Many of them can even produce code that is portable between different operating systems, and some even run with the appropriate native look and feel.
However, I'm not interested in the elements of a standard GUI. If I thought that these were the appropriate elements, then that's what I'd be using. What I wanted in a graphics system is as follows:
The X11 and PythonWin systems are platform specific, so they fail the test immediately. TkInter, Rivet, and WPY are all based on Tk (at least under X). In order to get the sort of generality I desire under Tk, you must use the canvas object. This is unfortunately much to slow to do anything useful. WXWindows was the most promising of the candidates that I looked at (other than OpenGL); however, I found that its great pains to maintain native look-and-feel (which is a big plus to most people) were a big hinderance to my plans.
"The OpenGL graphics system is a software interface to graphics hardware. It allows you to create interactive programs that produce color images of moving three-dimensional (and two-dimensional) objects." - OpenGL Programming Guide
Open GL is a portable graphics standard, currently supported on all major computer platforms. Because the high-performance implementation of OpenGL can be expensive on some platforms, it is reassuring that a freely available implementation of the OpenGL standard exists (Mesa). This implementation compiles almost everywhere that python does (not including DOS) and is an efficient implementation of the API on top of the native window system.
OpenGL is fast. It was designed to produce "color images of moving three-dimensional objects." This is an extremely computationally demanding operation. Speed of the basic drawing primitives was and continues to be a primary motivating factor in the system's design. With systems that have hardware graphics acceleration, this can produce performance that is even faster than raw XLib coding (the fastest (and ugliest) of the other systems considered here).
The library's design is clean, easy to understand and natural to work with. It gives you the power to perform the finest grained manipulations on the graphical output without requiring the sorts of obscure technical details of working with something like Xlib.
The great thing about building this project in python has been the phenomenal speed with which I was able to go from nothing to a working prototype. Now that I have something working, there are one or two chunks of code that are acting as bottle necks in the program. The standard python approach is to move these speed critical blocks of code down into C.
Having translated a fairly large amount of simple python code to C recently, I've noticed that much of the translation is trivial if I include static types in the function specification.
To use the most overused example of function definition, here it is folks, the venerable factorial function.
def factorial(n): if n == 0: return 1 else: return n*factorial(n-1)
Now, what does this look like in C?
long py2c_Factorial_factorial(long n) { if (n == 0) { return 1; } else { return (n*py2c_Factorial_factorial( (n-1) ); } }
The reason that some of the names are a little long, and that there are a few more parenthesis than you might expect in such a piece of code is that this was automatically generated from the python source. Of course, the key to making this work was the addition to the python source file of the following single line.
#DECLARE factorial:(long, long)
This tells the translation program the signature of the factorial function. Without this information, doing anything useful with this function is virtually impossible. Including static types in this manner is definately a sacrifice of python's outstanding dynamic properties, but it's exactly the sacrifice expected in order to translate to efficient C code.
I've just recently discovered the MESS project, and it's interesting to note that that framework involves similar static type declarations for python classes. What it has that this work currently doesn't is the ability to declare a variable as a generic python object. This of course sacrifices much of the speed gains of translating to C, so its not a top priority for me.
The final step in the translation to C is to produce a python interface to the newly generated C function so that it can be used as before. This is done fairly trivially with Bgen (since the function's signature is known).
Obviously I haven't just created a general purpose tool for translating python code to C. If I'd done that there'd have been much more fanfare, and I anticipate that there'd be much rejoicing throughout the land. Instead, I've gone a long way towards automating the process of translating very simple python code to C.
The key idea is that static typing has its uses, and that while all of us love the dynamic nature of python, it can be very useful to abandon it at particular moments. I've had many situations (particularly with my numeric code) where I've wanted to statically type a function, not for speed requirements, but for code reliability. I think that there are some interesting gains to be made by continuing to work in this direction. | http://www.python.org/workshops/1996-06/papers/hugunin.IPCIV.html | crawl-002 | en | refinedweb |
In Chapter 3, we explained the basics of Django view functions and URLconfs. This chapter goes into more detail about advanced functionality in those two pieces of the framework.
Consider this URLconf, which builds on the example in Chapter 3:
from django.conf.urls.defaults import * from mysite.views import current_datetime, hours_ahead, hours_behind, now_in_chicago, now_in_london urlpatterns = patterns('', (r'^now/$', current_datetime), (r'^now/plus(\d{1,2})hours/$', hours_ahead), (r'^now/minus(\d{1,2})hours/$', hours_behind), (r'^now/in_chicago/$', now_in_chicago), (r'^now/in_london/$', now_in_london), )’ve got'^now/$', views.current_datetime), (r'^now/plus(\d{1,2})hours/$', views.hours_ahead), (r'^now/minus(\d{1,2})hours/$', views.hours_behind), (r'^now/in_chicago/$', views.now_in_chicago), (r'^now/in_london/$', views.now_in_london), )'^now/$', 'mysite.views.current_datetime'), (r'^now/plus(\d{1,2})hours/$', 'mysite.views.hours_ahead'), (r'^now/minus(\d{1,2})hours/$', 'mysite.views.hours_behind'), (r'^now/in_chicago/$', 'mysite.views.now_in_chicago'), (r'^now/in_london/$', 'mysite.views.now_in_london'), )'^now/$', 'current_datetime'), (r'^now/plus(\d{1,2})hours/$', 'hours_ahead'), (r'^now/minus(\d{1,2})hours/$', 'hours_behind'), (r'^now/in_chicago/$', 'now_in_chicago'), (r'^now/in_london/$', 'now_in_london'), )
Note that you don’t put a trailing dot (".") in the prefix, nor do you put a leading dot in the view strings. Django puts that in automatically.
With these two approaches in mind, which is better? It really depends on your personal coding style and needs.
Advantages of the string approach are:
Advantages of the function object approach are:'^/?$', 'mysite.views.archive_index'), (r'^(\d{4})/([a-z]{3})/$', 'mysite.views.archive_month'), (r'^tag/(\w+)/$', 'weblog.views.tag'), )
New:
from django.conf.urls.defaults import * urlpatterns = patterns('mysite.views', (r'^/?$', 'archive_index'), (r'^(\d{4})/([a-z]{3})/$','archive_month'), ) urlpatterns += patterns('weblog.views', (r'^tag/(\w+)/$', 'tag'), )
All the framework cares about is that there’s a module-level variable called urlpatterns. This variable can be constructed dynamically, as we do in this example.
In all of our URLconf examples so far, we’ve used simple, non-named regular-expression groups — i above.
If you use both named and non-named groups in the same pattern in your URLconf, you should be aware of how Django treats this special case. Here’s the algorithm the URLconf parser follows, with respect to named groups vs. non-named groups in a regular expression:
Sometimes you’ll find yourself writing view functions that are quite similar, with only a few small differences. For example, say you’ve got_to_response from mysite.models import MyModel def foo_view(request): m_list = MyModel.objects.filter(is_new=True) return render_to_response('template1.html', {'m_list': m_list}) def bar_view(request): m_list = MyModel.objects.filter(is_new=True) return render_to_response('template2.html', {'m_list': m_list})
We’re repeating ourselves in this code, and that’s inelegant. At first, you may think to remove the redundancy by using the same view for both URLs, putting parenthesis_to_response from mysite.models import MyModel def foobar_view(request, url): m_list = MyModel.objects.filter(is_new=True) if url == 'foo': template_name = 'template1.html' elif url == 'bar': template_name = 'template2.html' return render_to_response(template_name, {'m_list': m_list})
The problem with that solution, though, is that it couples your URLs to your code. If you decide to rename /foo/ to /fooey/, you’ll have to remember to change the view code.
The elegant solution involves a feature called extra URLconf options._to_response from mysite.models import MyModel def foobar_view(request, template_name): m_list = MyModel.objects.filter(is_new=True) return render_to_response’ll cover in Chapter 9.
Here are a couple of ideas on how you can use the extra URLconf options technique in your own projects:
Say you’ve got this:
is straightforward — it’s nothing/. We can take advantage of extra URLconf options like so:
urlpatterns = patterns('', (r'^mydata/birthday/$', views.my_view, {'month': 'jan', 'day': '06'}), (r'^mydata/(?P<month>\w{3})/(?P<day>\d\d)/$', views.my_view), )
The cool thing here is that we don’t have to change_to_response from mysite.models import Event, BlogEntry def event_list(request): obj_list = Event.objects.all() return render_to_response('mysite/event_list.html', {'event_list': obj_list}) def entry_list(request): obj_list = BlogEntry.objects.all() return render_to_response(_to_response def object_list(request, model): obj_list = model.objects.all() template_name = 'mysite/%s_list.html' % model.__name__.lower() return render_to_response(template_name, {'object_list': obj_list})
With those small changes, we suddenly have a reusable, model-agnostic view! From now on, any time we need a view that lists a set of objects, we can simply reuse this object_list view rather than writing view code. Here are a couple of notes about what we did:
We’re passing the model classes directly, as the model parameter. The dictionary of extra URLconf options can pass any type of Python object — not just strings.
The model.objects.all() line is an example of duck typing: “If it walks like a duck and talks like a duck, we can treat it like a duck.” Note the code doesn’t know what type of object model is; the only requirement is that model have an objects attribute, which in turn has an all() method.
We’re using model.__name__.lower() in determining the template name. Every Python class has a __name__ attribute that returns the class name. This feature is useful at times like these, when we don’t know the type of class until runtime.
For example, the BlogEntry class’ __name__ is the string 'BlogEntry'.
In a slight difference between this example and the previous example, we’re passing the generic variable name object_list to the template. We could easily change this variable name to be blogentry_list or event_list, but we’ve left that as an exercise for the reader.
Because database-driven Web sites have several common patterns, Django comes with a set of “generic views” that use this exact technique to save you time. We’ll cover Django’s built-in generic views in the next chapter._to_response. Those astute readers would be correct. We bring this up only to help you avoid making the mistake.
Another convenient trick is to specify default parameters for a view’s arguments. This tells the view which value to use for a parameter by default if none is specified.
For example:
# urls.py from django.conf.urls.defaults import *.
It’s common to use this technique in conjunction with configuration options, as explained above. This example makes a slight improvement to the example in the Giving a view configuration options section by providing a default value for template_name:
def my_view(request, template_name='mysite/my_view.html'): var = do_something() return render_to_response, the “add an object” pages in Django’s admin site are represented by this URLconf line:
urlpatterns = patterns('', # ... ('^([^/]+)/([^/]+)/add/$', 'django.contrib.admin.views.main.add_stage'), # ... )
This matches URLs such as /myblog/entries/add/ and /auth/groups/add/. However, the “add” page for a user object (/auth/user/add/) is a special case — it doesn’t display all of the form fields, it displays two password fields, etc. We could solve this/$', 'django.contrib.admin.views.auth.user_add_stage'), ('^([^/]+)/([^/]+)/add/$', 'django.contrib.admin.views.main string, regardless of what sort of match the regular expression makes. For example, in this URLconf line:
(r'^articles/(?P<year>\d{4})/$', views.year_archive),
…the year argument to views.year_archive() will be a string, not an integer, even though the comprised normal Python string (not as a Unicode, HEAD — is not taken into account when traversing the URLconf. In other words, all request methods will be routed to the same function for the same URL. It’s the responsibility of a view function to perform branching based on request method. only useful if you’re certain that every view in, these.
This chapter is not yet finished. What else would you like to see? Leave a comment on this paragraph and let us know! Interaction is cool.. | http://www.djangobook.com/en/beta/chapter08/ | crawl-002 | en | refinedweb |
The internet can be a scary place.
In the past few years, internet horror stories have been in the news almost continuously. We’ve seen viruses spread with amazing speed, swarms of compromised computers wielded as weapons, a never-ending arms race against spammers, and many, many reports of identify theft from compromised web sites.
As good web developers, it’s our duty to do what we can to combat these forces of darkness. Every web developer needs to treat security as a fundamental aspect of web programming. Unfortunately, it turns out that security is hard — attackers only need to find importantly — the steps you can take to make your code even more secure.
First, though, an important disclaimer: we’re in no way experts in this realm, cracker or script kidd info. in the wild.
This vulnerability most commonly crops up when constructing SQL “by hand” from user input. For example, imagine writing a function to gather a list of a contact info from a contact search page. To prevent spammers from reading every single email in our system, we’ll force the user to type in someone’s username before we provide their email email! Where’d our contact list go?.backend.quote_name, which will escape the identifier according to the current database’s quoting scheme.
Probably the most common web vulnerability, cross-site scripting, or XSS, is found in web applications that fail to properly escape user-submitted content before rendering it into HTML. This allows an attacker to maliciously insert arbitrary HTML, usually in the form of <script> tags.
Attackers often use XSS attacks to steal cookie and session info, or to trick users into giving private information to the wrong person (a.k.a phishing).
This type of attack can take a number of different forms, and has almost infinite permutations, so we’ll just look at a typical example. Let’s look at a extremely simple “hello world” view:
def say_hello(request): name = request.GET.get('name', 'world') return render_to_response("hello.html", {"name" : name})
This view simply reads a name from a GET parameter and passes that name to the hello.html template. We might write a template for this view like:
<h1>Hello, {{ name }}!</h1>
So if we accessed, the rendered page would contain:
<h1>Hello, Jacob!</h1>
But wait — what happens if we access<i>Jacob</i>? Then we’d get:
website, but in fact is an XSS-hijacked form that submits your back account information to an attacker.
This gets worse if you storing this data in the database and later display it it on your site.
For example, at one point MySpace was violoates the assumed trust that all the code on MySpace is actually written by MySpace.
MySpace was extremely lucky that this malicious code didn’t automatically delete viewer’s accounts, change their passwords, flood the site with spam, or any of the other nightmare scenarios this vulnerability unleashes.
The solution is simple: always escape any content that might have come from a user. If we simply rewrite our template as:
<h1>Hello, {{ name|escape }}!</h1>
then we’re no longer vulnerable. You should always use the escape tag (or an analogue) when displaying user-submitted content on your site.
Why doesn’t Django just do this for you?
Modifying Django to automatically escape all variables displayed in templates is a frequent topic of discussion on the Django developer mailing list.
So far, Django’s templates have avoided this behavior because it subtley and invisibly changes what should be relatively streightforward behavior (displaying variables). It’s a tricky issue and a difficult trade-off to evaluate. Adding hidden implicit behavior is against Django’s core ideals (and Python’s, for that matter), but security is equally important.
All this to say, then, that there’s a fair chance that Django will grow some form of auto-escaping (or nearly-auto-escaping) behavior in the future. It’s always a good idea to check the official Django documentation; it’ll always be more up-to-date than this book (especially the dead-tree version).
Even if Django does add this feature, however, you should still be in the habit of thinking “where does this data come from?” at all times. No automatic solution will ever protect your site from XSS attacks 100% of the time.
CSRF happens when a malicious Web site tricks a user into unknowingly loading a URL from a site at which they’re already authenticated — hence, taking advantage of their authenticated status.
Django has built-in tools to protect from this kind of attack; both the attack itself and those tools are covered in great detail in Chapter fake session ID (perhaps obtained through a man-in-the-middle attack) to pretend to be another user.
An example of this first two would be an attacker in a coffee shop using the wireless network to capture a session cookie; he could then use that cookie to impersonate the original user.
A cookie forging attack, where an attacker overrides the supposedly read-only data stored in a cookie. Chapter 12 explains in details almost too easy to exploit these types of attackers.
On a more subtle level, though, it’s never a good idea to trust anything stored in a cookie; you never know who’s been poking at them.
Session fixation, where an attacker tricks a user into setting or reseting their session ID.
For example, PHP allows session identifiers to be passed in the URL (i.e.). An attacker who tricks a user into clicking on a link with a hardcoded session ID will cause the user to pick up that session.
This has been used in phishing attacks to trick users into entering personal information into the an account which on a link to submit a “color” that actually contains an XSS attack; if that color isn’t escaped (see above) the user could again inject malicious code into the user’s environment.
There are a number of general principles that can protect from these attacks:
Never allow session information to be contained in the URL.
Django’s session framework (see Chapter 12) XSS section above, and remember that it applies to any user-created content. You should treat session information as they try a non-existent one which prevent session fixation.
Notice that none of those principles and tools prevent man-in-the-middle attacks. These types of attacks are nearly impossible to detect. If your site allows logged-in users to see any sort of sensitive data, you should always serve that site over HTTPS. Additionally, if you’ve got an SSL-enabled site, you should set the SESSION_COOKIE_SECURE setting to True; this will make Django only send session cookies over HTTPS.
SQL injection’s less-well-known sibling, e-mail header injection hijacks email-sending web forms and uses them to send spam. Any form that constructs email headers from web form data is a target for this kind of attack.
Let’s look at the canonical contact form found on many sites. Usually this emails a hard-coded email address, and so at first glance doesn’t appear vulnerable to spam abuse.
However, most of these forms also allow the user to type in his own subject for the email (along with a from address, body, and sometimes a few other fields). This subject field is used to construct the “subject” header of the email message.
If that header is unescaped when building the email message, an attacker could use something like "hello\ncc:spamvictim@example.com" (where "\n” is a newline character). That would make the constructed email headers turn into:
To: hardcoded@example.com Subject: hello cc: spamvictim@example.com
Like SQL injection, if we trust the subject line given by the user, we’ll allow him to construct a malicious set of headers, and and the subject). If you try to use django.core.mail.send_mail with a subject that contains newlines, Django will raise a BadHeaderError exception.
If you decide to use other methods of sending email,() # ...
Thought it looks like that view restricts file access to files beneath BASE_PATH (by using os.path.join), if the attacker passes in a filename containing .. (that’s two periods, the UNIX shorthand for “the parent directory”), he can access files “above” BASE_PATH. It’s only a matter of time before he very carefully sanitize the requested path to ensure that an attacker isn’t able to escape from the base directory you’re restricting access to.
Note
Needless to say, you should never write code that can read from any area of the disk!
A good example of how to do this escaping lies in the Django’s built-in static content serving view (in django.views.static). Here’s the relevant code:
import os import posixpath # ... path = posixpath.normpath(urllib.unquote(path)) newpath = '' for part in path.split('/'): if not part: # strip empty path components continue drive, part = os.path.splitdrive(part) head, part = os.path.split(part) if part in (os.curdir, os.pardir): # strip '.' amd '..' in path continue newpath = os.path.join(newpath, part).replace('\\', '/')
Django itself doesn’t read files (unless you use the static.serve function, but that’s protected with the code shown above), sometimes unintentionally.
Django has a simple flag that controls the display of these error messages. If the DEBUG setting is set to True, error messages will be displayed in the browser. If not, Django will render return a HTTP 500 (“internal server error”) message and render an error template that you provide. This error template is called 500.html, and should live in the root of one of your template directories.
Since developers still need to see errors generated on a live site, any errors handled this way will send an email with the full traceback to any addresses given in the ADMINS setting.
Users deploying under Apache and mod_python should also make sure they have PythonDebug Off in their Apache conf files; this will ensure that any errors that occur before Django’s had a chance to load won’t be displayed publicly.
Hopefully all this talk of security problems isn’t too intimidating. It’s true that the web can be a wild and wooly world, but with a little bit of foresight you can have an incredibly secure website. month or week researching and keeping current on the state of web application security. It’s a small investment to make, but the protection you’ll get for your site and your users is priceless.
Did we miss anything? Are there other security vulnerabilities you think we should cover in this chapter? Did we get something wrong ($DEITY forbid)? Leave a note on this paragraph and let us know!. | http://www.djangobook.com/en/beta/chapter20/ | crawl-002 | en | refinedweb |
I've been playing around with the version of the WPµ source that's used on Blogsome's servers, trying to find the exact point where the bug is that escapes apostrophes and quotes.
Basically, the XMLRPC client contacts the server, and sends the data in. According to the console, the content of the post is actually in a field called description.
Searching through the XMLRPC file I find only five references to the word description. Two of these are in functions to do with posting. Both are basically the same, one is for blogger, the other metaweblog type connections:
$post_content = apply_filters('content_save_pre', $content_struct['description']);
Now, a bit of research showed up that apply_filters is a function that allows plugins and their ilk to access the data before it gets saved to the database. Now, I'm fairly sure it's not a plugin doing this.
I also discovered that it's likely that the update to XMLRPC.php that happened was accompanied by a change to another file, that calls stripslashes(), another WP function. The XMLRPC update was, after all, a fix that removed the ability for XMLRPC calls to run unescaped code. So it makes sense that it escapes stuff.
In the short term, I discovered ecto has the ability to automatically run a script as you post: in the New Post window, make sure Options are showing, and choose the Formatting tab. (Incidentally, if you are only using double-quotes, it seems the Smarten Quotes will help, but it may mess with code).
I use a script that is like this to fix everything up:
import sys data = open(sys.argv[1]).read() data = data.replace(“'”,“'”) data = data.replace('“',”“”) open(sys.argv[1],'w').write(data)
This on it's own is not enough - I seemed to have to go into the HTML editing mode before it would work. I think ecto does it's own conversion of certain HTML entities to real characters.
This post is a test post to see how it all goes with
<pre> tags and the like. | http://schinckel.net/2005/10/16/ | crawl-002 | en | refinedweb |
Web applications accessed from traditional HTML browsers running on desktops make assumptions about such client capabilities as screen size, bandwidth, support for color images, and so on. These assumptions break down when the same content is accessed from mobile devices, whose capabilities are more limited – and varied. The challenge for application developers is to support thousands of mobile devices with widely varying capabilities. Customizing content for different devices, and for different users, requires significant investments of time and effort.
One way to ensure compatibility among the largest set of devices is to settle for the least common denominator, but then users of high-end devices are limited to the capabilities of lower-end devices, and there is little scope for user preferences. The challenge is then: How do you deliver content that reflects users' preferences and the capabilities of their devices without the time and effort of tailoring the code to each platform?
The World Wide Web Consortium (W3C) has finalized the Composite Capabilities/Preference Profiles (CC/PP) standard for representing device capabilities and user preferences. Using CC/PP, you design content once, then use tools to customize and deliver content in formats that specific mobile devices support, and that reflect settings specified by users. As a result, users can access the same application or content from any device, and be confident that it will work on that device, and will accommodate their preferences. This process has become easier for developers of applications based on Java technology since the development within the Java Community Process (JCP) of a standard set of Java APIS for handling CC/PP information, CC/PP Processing (JSR 188).
To give you a fast-track introduction to CC/PP and to JSR 188; this article:
Legacy Means of Adapting Content to Device Capabilities
In the past, to adapt content for multiple devices, web applications and HTTP servers have conveyed information on device capabilities in HTTP headers. The two widely used approaches are:
User-Agent
User-Agent: Mozilla/4.0 (compatible; MSIE 5.01; Windows 98; YComp 5.0.0.0)
User-Agent: Mozilla/4.0 (compatible; MSIE 5.01; Windows 98; YComp 5.0.0.0)
An application can examine the User-Agent and select content accordingly. Note, however, that the application adapts content, not based on particular capabilities of the device, but only on its identity; e.g., a cell phone such as the Motorola A760 or a web browser such as Microsoft Internet Explorer 6.0.
Accept
Accept-Charset
Accept-Encoding
Accept-Language
This sample HTTP request shows how Accept request headers are used:
GET / HTTP/1.1
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg,
application/vnd.ms-powerpoint, application/vnd.ms-excel,
application/msword, */*
Accept-Language: en-ca
Accept-Encoding: gzip, deflate
The problem is that browsers may not provide full or correct information. Consider this field from one browser's request header:
Accept: */*
Accept: */*
This asserts that the browser will accept any media type – which is simply no help from a content adaptation point of view.
Introduction to CC/PP
An application can use the CC/PP framework to discover information about the user's mobile device. CC/PP defines a model for formalizing device profiles – describing device capabilities and user preferences – and a mechanism for sending a profile to the content server along with web page requests: The client's browser adds to the HTTP request a header containing a URL for the device profile. When a content server receives an HTTP request containing a CC/PP reference, it processes the request, follows the URL to the profile, and uses the information it finds there to format content that's suited to the device and to the user's preferences, all automatically.
CC/PP was originally designed to support device independence: when a device's browser requests content, servers and proxies can customize the content to the target device. UAProf, developed by the Open Mobile Alliance (OMA), is a concrete implementation of CC/PP aimed at mobile devices that support the Wireless Application Protocol (WAP).
Today, CC/PP is an industry standard for describing a delivery context, a set of attributes that characterizes the capabilities of the access mechanisms and the preferences of the user. CC/PP represents device capabilities as a two-level hierarchy that consists of attributes grouped into components. Here's a simple example of a list of two components, Hardware Capabilities and Software Capabilities, and their attributes:
In the next example, a simple profile shows data that might be encoded in a CC/PP profile:
Vocabulary = ""
Hardware
ImageCapable = Yes
InputCharSet = {US-ASCII,ISO-8859-1]
Model = SomeModelNumber
ScreenSize = 120x102
SoftKeysCapable = Yes
Vendor = SomeVendorName
Software
CcppAccept = {application/vnd.wap.wml,image/vnd.wap.wbmp}
OSVendor = SomeOtherVendorName
BrowserUA
BrowserName = SomeBrowserName
BrowserVersion = 1.1
Vocabularies
One of the first things to note about the sample profile is that it uses a vocabulary, a set of valid component names, valid attribute names, data types of the attributes, and so on. In other words, the vocabulary defines the format and the language used to communicate profile information between senders and receivers. The W3C document CC/PP Structures and Vocabularies defines the structure of profile information as a set of components containing a set of attributes. It's important to note that the CC/PP is independent of any particular vocabulary and therefore doesn't define what components and attributes must be used in a profile. This latitude enables any application to define its own vocabulary. In other words, CC/PP can be extended through the introduction of new vocabularies, and therefore applications that use CC/PP may define different vocabularies tailored to specific application domains.
One important example vocabulary is that of UAProf because the majority of CC/PP-capable devices use UAProf. The UAProf vocabulary has six components:
HardwarePlatform
SoftwarePlatform
NetworkCharacteristics
BrowserUA
WapCharacteristics
PushCharacteristics
Along with CC/PP and UAProf, W3C recommends the use of the Resource Description Framework (RDF) Schema for defining vocabularies. CC/PP is actually based on RDF, which provides the mechanisms for exchanging modular and interoperable metadata across different resource description communities. RDF itself uses XML for its syntax. Basically, RDF provides a model for describing resources that have properties or attributes and characteristics. RDF Schema is beyond the scope of this article, but you can find more about it in W3C's RDF Vocabulary Description Language 1.0: RDF Schema.
Each vocabulary is associated with an XML namespace. XML namespaces define a notation for associating user-friendly name forms with arbitrary URIs. In CC/PP they're used to create identifying URIs for RDF core elements, CC/PP structural elements, and CC/PP attribute vocabularies. This XML snippet contains three namespace declarations:
<?xml version="1.0"?>
<RDF xmlns:rdf=""
xmlns:ccpp=""
xmlns:
The first namespace declaration is for RDF use. The second names the CC/PP structural vocabulary, and the third names a component CC/PP properties vocabulary.
Sample CC/PP Profile
Recall that a CC/PP profile is a description of a device's capabilities and of user preferences that can be used to guide the adaptation of content presented to that device. It contains one or more components, and each component contains one or more attributes. Code Sample 1 shows a sample profile. As you can see, it defines the capabilities of the device as attributes grouped in components:
Code Sample 1: sample-profile.xml
<?xml version="1.0"?>
<rdf:RDF xmlns=""
xmlns:rdf=""
xmlns:ccpp=""
xmlns:
<rdf:Description rdf:
<ccpp:component>
<rdf:Description rdf:
<rdf:type
rdf:
<prf:BitsPerPixel>2</prf:BitsPerPixel>
<prf:InputCharSet>
<rdf:Bag>
<rdf:li>ISO-8859-1</rdf:li>
</rdf:Bag>
</prf:InputCharSet>
</rdf:Description>
</ccpp:component>
<ccpp:component>
<rdf:Description rdf:
<rdf:type
rdf:
-Language>
<rdf:Seq>
<rdf:li>en</rdf:li>
<rdf:li>ja</rdf:li>
</rdf:Seq>
</prf:CcppAccept-Language>
</rdf:Description>
</ccpp:component>
</rdf:Description>
</rdf:RDF>
A CC/PP Validation Service is available. You can use it to check CC/PP syntax, but it doesn't do any vocabulary check. Try it on sample-profile.xml.
sample-profile.xml
A server uses the attributes in a CC/PP profile to determine the most appropriate form of a resource to deliver to a client. A client can send a profile to a CC/PP-capable application handler on the server side using the indirect approach: sending a URI representing the default profile from the vendor-specific location. Where the user has defined preferences that aren't in the default profile, the device transmits the preferences inline.
Who Does What?
For CC/PP to work, several parties must participate. The good news is that everything's invisible to users unless they want to transmit preferences not found in the default profile, in which case some user configuration is required. The parties involved:
The Java CC/PP Processing Specification
JSR 188 defines a set of standard APIs for processing information about delivery contexts. The aim is to simplify the developerment of applications for the Java platform by providing standard APIs for processing information on device capabilities and user preferences in CC/PP profiles.
Note: JSR 188 is not intended to compete with J2EE Client Provisioning (JSR 124), which defines a standard for distributing client applications from J2EE environments. In fact, JSR 124 servers can use the CC/PP Processing APIs to identify client devices, and thus provide a flexible implementation that is independent of both the vocabulary and the protocol.
The JSR 188 Reference Implementation
The CC/PP processing APIs are independent of any particular CC/PP processing implementation. Version 1.0 of the RI uses HP's Jena Toolkit as the underlying RDF processor, but the pluggable architecture of the CC/PP Processing API allows you to use any conformant implementation. With the reference implementation, you can build fully functional CC/PP-enabled mobile applications.
You can download the API and RI for free. Then unzip the archive in your favorite directory; you'll get the following subdirectories:
api
doc
lib
samples
src
The samples directory contains a sample parser application, and the lib directory contains these JAR files:
ccpp-1_0.jar
javax.ccpp
javax.ccpp.uaprof
ccpp-ri-1_0.jar
jena-1.4.0.jar
rdffilter.jar
To use the reference implementation you need the J2SE SDK 1.4.1 or higher, and a Servlet/JSP container such as Sun Java Application Server Edition 8 or Apache Tomcat. For this article I've used Tomcat 4.1, which is the application server that the RI has been tested under.
Setting Up and Running the Sample Application
The samples directory contains a sample parser packaged as a .war file, ccpp-ri-parser-1_0.war. This contains all the necessary libraries, several vocabulary definition files, and JSPs to demonstrate the use of the Java CC/PP Processing API to parse CC/PP documents. To see the parser in action, deploy the .war file into your application server. Using Apache Tomcat, for example:
.war
ccpp-ri-parser-1_0.war war=
If all goes well, you'll see the main page as in Figure 1.
You can have the application parse the CC/PP profile that already appears in the text area, or supply a new profile or its URL to parse. If you parse the CC/PP profile shown in the text area, you'll see output like Figure 2.
As you can see in Figure 1 and others, the sample application includes a vocabulary manager as well as a parser: You can view, add, or remove vocabularies. Figure 3 shows the list of vocabularies that comes with the reference implementation.
You can view any of the vocabularies. Figure 4 shows a snapshot of one.
Programming With the CC/PP Processing APIs
The JSR 188 reference implementation comprises three packages:
com.sun.ccpp
DescriptionManager
ProfileFactory
To give you an idea of the modest effort involved in using these classes, Code Sample 2 shows you how an application can use the APIs to query a profile and print its components and attributes. In this example the profile is read from a local file; for a real-world application you can easily modify the code to read the profile from an HTTP request, using ServletContext.getResource().
ServletContext.getResource()
The ProfileFactory class implements the Abstract Factory design pattern, and is the entry point for most applications. The concrete class must be configured to create Profile objects, easily done using the method ProfileFactory.setInstance(ProfileFactory). If getInstance() is called before the concrete class is configured, it will return a null. The same is true for the ProfileFragmentationFactory class, which you can use to create profiles from input streams, strings, or URLs.
Profile
ProfileFactory.setInstance(ProfileFactory)
getInstance()
null
ProfileFragmentationFactory
The next step is to configure the vocabulary used in the profile. You can configure multiple vocabularies so that your application can query different profiles that use different vocabularies. This example, however, queries only one: sample-profile.xml, Code Sample 1. To configure vocabularies you use the DescriptionManager class. The CC/PP Processing specification defines an XML schema to represent parent vocabularies and extensions, vocabulary.xsd, which is used to validate CC/PP vocabulary definition files. The schema comes with the reference implementation as part of the sample .war file. Once the schema is set, vocabulary definitions can be added to the system. The example uses this schema, and adds three vocabularies, ccppschema-20010430.xml, ccppschema-20010430a.xml, and ccppschema-20010430b.xml, because these represent the vocabulary defined in sample-profile.xml.
vocabulary.xsd
ccppschema-20010430.xml
ccppschema-20010430a.xml
ccppschema-20010430b.xml
The next step is to construct a Profile object from the CC/PP profile defined in a file, then query the profile to list its components and attributes.
Code Sample 2: QueryProfile.java
import java.io.*;
import java.net.*;
import java.util.*;
import javax.ccpp.*;
import com.sun.ccpp.*;
public class QueryProfile {
// Construct a Profile object from an XML profile file
public Profile getProfileFromFile(File ccppFile) throws FileNotFoundException {
ProfileFactory pf = ProfileFactoryImpl.getInstance();
//ProfileFactory.setInstance(pf);
ProfileFragmentFactory ff = ProfileFragmentFactoryImpl.getInstance();
//ProfileFragmentFactory.setInstance(ff);
//Configure the vocabulary
DescriptionManager dm = DescriptionManager.getInstance();
try {
// set the schema
File schema = new File("vocabulary.xsd");
DescriptionManager.setSchema(schema);
File vocab = null;
vocab = new File("ccppschema-20010430.xml");
dm.addVocabulary(vocab);
vocab = new File("ccppschema-20010430a.xml");
dm.addVocabulary(vocab);
vocab = new File("ccppschema-20010430b.xml");
dm.addVocabulary(vocab);
} catch(Exception e) {
e.printStackTrace();
}
// Read the CC/PP profile from a file
InputStream is = new FileInputStream(ccppFile);
ProfileFragment pfa[] = new ProfileFragment[1];
pfa[0] = ff.newProfileFragment(is);
return pf.newProfile(pfa);
}
// Given a profile, list its attribute name/value pairs
public void processProfile(Profile profile) {
Set comps = profile.getComponents();
for(Iterator i = comps.iterator(); i.hasNext(); ) {
Component comp = (Component) i.next();
System.out.println("Component: " + comp.getName());
Set attrs = comp.getAttributes();
for(Iterator j = attrs.iterator(); j.hasNext(); ) {
Attribute attr = (Attribute) j.next();
Object value = attr.getValue();
System.out.println("\tAttribute: " + attr.getName() +
" = " + attr.getValue());
}
}
}
public static void main(String argv[]) throws Exception {
if(argv.length != 1) {
System.out.println("Usage: java QueryProfile [profileName.xml]");
System.exit(0);
}
QueryProfile p = new QueryProfile();
File f = new File(argv[0]);
Profile profile = p.getProfileFromFile(f);
// If the profile is null then something went wrong
if(profile == null) {
System.out.println("Null profile");
} else {
// Print vocabulary information
ProfileDescription pd = profile.getDescription();
System.out.println("Vocabulary: "+pd.getURI());
// process the profile
p.processProfile(profile);
}
}
}
To experiment with this application:
SampleApp
QueryProfile
.java
QueryProfile.java
javac
jre\lib\ext
You are now ready to run the QueryProfile application using the standard java interpreter:
java
java QueryProfile sample-profile.xml
Here's the output you should see:
Vocabulary:
Component: SoftwarePlatform
Attribute: CcppAccept-Language = [en, ja]
Attribute: CcppAccept-Charset = [UTF-8, ISO-8859-1, US-ASCII, ISO-10646-UCS-2]
Component: HardwarePlatform
Attribute: BitsPerPixel = 2
Attribute: InputCharSet = [ISO-8859-1]
Note that this output resembles Figure 2 – no surprise, really: The CC/PP profile we have parsed, sample-profile.xml, is the profile that comes with the JSR 188 RI.
Conclusion
The task of developing and delivering device-independent mobile applications is complex primarily because the thousands of different client devices have such widely varying capabilities. The task became easier, however, with the advent of Composite Capabilities/Preference Profiles, a standard for representing device capabilities and user preferences, and of the Java CC/PP Processing specification, a standard set of Java APIs for parsing and querying CC/PP profiles.
This article presented an introduction to the CC/PP and JSR 188 standards, and provided code samples that show how easy it is to use the CC/PP processing APIs.
As you develop CC/PP-capable applications, do keep security in mind. A CC/PP profile may contain sensitive information, and the CC/PP standard itself doesn't address such issues. It is intended to be used in conjunction with appropriate trust and security mechanisms.
For More Information
Acknowledgments
Special thanks to Luu Tran and Kenneth K. Lui of Sun Microsystems, whose feedback helped me improve this article.
About the author
Qusay H. Mahmoud provides Java technology consulting and
training services. He has published dozens of Java articles, and is the author of Distributed Programming with Java (Manning Publications, 1999) and Learning Wireless Java (O'Reilly, 2002). | http://developers.sun.com/mobility/midp/articles/ccpp/ | crawl-002 | en | refinedweb |
Created on 2007-11-10 05:58 by gvanrossum, last changed 2007-11-10 22:13 by gvanrossum.
Here's an implementation of the idea I floated recently on python-dev
(Subject: Declaring setters with getters). This implements the kind of
syntax that I believe won over most folks in the end:
@property
def foo(self): ...
@foo.setter
def foo(self, value=None): ...
There are also .getter and .deleter descriptors. This includes the hack
that if you specify a setter but no deleter, the setter is called
without a value argument when attempting to delete something. If the
setter isn't ready for this, a TypeError will be raised, pretty much
just as if no deleter was provided (just with a somewhat worse error
I intend to check this into 2.6 and 3.0 unless there is a huge cry of
dismay. Docs will be left to volunteers as always.
Looks great (regardless of how this is implemented). I always hated this
def get_foo / def set_foo / foo = property (get_foo, set_foo).
propset2.diff is a new version that improves upon the heuristic for
making the deleter match the setter: when changing setters, if the old
deleter is the same as the old setter, it will replace both the deleter
and setter.
This diff is relative to the 2.6 trunk; it applies to 3.0 too.
propset3.diff removes the hack that makes the deleter equal to the
setter when no separate deleter has been specified. If you want a
single method to be used as setter and deleter, write this:
@foo.setter
@foo.deleter
def foo(self, value=None): ...
Fixed a typo:
+PyDoc_STRVAR(getter_doc,
+ "Descriptor to change the setter on a property.");
^^^
Checked into trunk as revision 58929. | http://bugs.python.org/issue1416 | crawl-002 | en | refinedweb |
#include <OP_GalleryManager.h>
Definition at line 32 of file OP_GalleryManager.h.
Adds an extra category even if no entry subscribes to it.
Gets the sort order of categories (when parent name is not a string). Optionally the parent category may be provided in the form of a string encoding subcategories separated with a slash. When the parent category name is given, returns the order of sub-categories, if parent is found, otherwise ther returned array will be empty.
Gets a list of extra categories added for the given optable.
Returns the array of all keywords used by entries in all galleries that match the requirement of the optable. | http://www.sidefx.com/docs/hdk/class_o_p___gallery_manager.html | CC-MAIN-2018-51 | en | refinedweb |
Hi.
Video -
Video -
I request you to go through my previous page and do the exact same steps as per below recap -
- Download -
- Install Android Studio -click here
- Open android studio and create a new project - How to create android project?
5. Click on build.gradle in app you will see all the libs added like below. But you need to Add TestNG specific Libs given below -
testCompile 'org.assertj:assertj-core:2.0.0' testCompile 'org.testng:testng:6.9.10'
6. Add below TestNG test case by creating new Java Class in src->main
public class TestNGSampleTestCase{ AppiumDriver driver; @BeforeTest(); captureScreenShots("Seekbar"); } @AfterTest public void testCaseTearDown() { driver.quit(); } }
7. Running the TestNG test case
- Click on build variant
- Select Unit Testing
- Start the appium server with Specific port "4444"click here
- Connect device with USB debugging on or start an emulator.
- Right click on the test class and click on "Run".
It says cannot resolve the method captureScreenShots. Is this a user defined method? please help
Yes it is user defined method. This post is to explain Test Suit structure using testNG framework. If you want to write code to capture screenshot then refer -
Thank you
About the error you are getting please remove the below line from your depencies in build.gradle
testCompile 'junit:junit:4 removing junit line getting this error -
Error:Gradle: Execution failed for task ':app:transformClassesWithDexForDebug'.
> com.android.build.api.transform.TransformException: com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command 'C:\Program Files\Java\jdk1.8.0_73\bin\java.exe'' finished with non-zero exit value 2
add this -
multiDexEnabled true
in defaultconfig
{
multiDexEnabled true
}
Hi,
I am also getting same error:
Error:Gradle: Execution failed for task ':app:transformClassesWithJarMergingForDebug'.
> com.android.build.api.transform.TransformException: java.util.zip.ZipException: duplicate entry: io/appium/java_client/android/AndroidDeviceActionShortcuts.class
Now seeing the below errors. I have added testCompile 'org.testng:testng:6.9.10' in build.gradle.
Error:Gradle: Execution failed for task ':app:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.
Error:(5, 29) Gradle: error: package org.testng.annotations does not exist
Error:(6, 29) Gradle: error: package org.testng.annotations does not exist
Error:(7, 29) Gradle: error: package org.testng.annotations does not exist
Error:(23, 5) Gradle: error: cannot find symbol class BeforeTest
Error:(37, 5) Gradle: error: cannot find symbol class Test
Error:(61, 5) Gradle: error: cannot find symbol class AfterTest
Have synced gradle after making changes? did the sync went sucessful? once you do it add necessary imports then you will be good to go
Yes the gradle is synced successfully and imports are added. I have sent you an email which has screenshots
This comment has been removed by the author.
Hi we configure TestNG android studio but we try to execute individual testcase
we facing this issue below:
org.testng.TestNGException: org.xml.sax.SAXParseException; lineNumber: 3;
columnNumber: 44; Attribute "parallel" with value "none" must have a value from the list "false methods tests classes instances ".
but executing througt testng.xml working fine, individual testcase not working
6. Add below TestNG test case by creating new Java Class in src->main
according to step 6 of this tutorial do i need to create java class directly under main folder or in java folder under main. Kindly suggest.
you need to create java class under src ->main ->java
Hi Anuja, Hope you are doing well.
I am stuck at the first line in my code. I am trying to use testng with appium. But getting error while initializing DesiredCapabilities instance.
Error: Cannot resolve symbol- DesiredCapabilities
Thanks.
Hi, please check that your Appium Setup is successfully built and all the required libs are added in dependency section. Then your error will get resolved check this out
Regards,
Anuja
Thanks Anuja. It was due to the missing selenium jar file. Santosh
Im getting the same error.I have followed the same steps mentioned in the blog to setup appium .Can you tell which selenium jar file was missing ?
Hi Anuja!
In build.gradle:
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
but i want use TestNG. May be this string need to be replased?
Hi Anuja
I am new to Android Studio. I am Created the project as you mentioned in your blog "Appium Setup in Android Studio with TestNG" but facing this following Error. I have added testng dependencies, also copied the testng-6.9.9 jar file to libs folder and added to library. Can you help :-)
org.testng.TestNGException:
Cannot find class in classpath: TestNGSampleTestCase
at org.testng.xml.XmlClass.loadClass(XmlClass.java:81)
I have set up my project with above configuration and it will throw me error and not able to complete.
Error:Gradle: Execution failed for task ':app:transformClassesWithJarMergingForDebug'.
> com.android.build.api.transform.TransformException: java.util.zip.ZipException: duplicate entry: org/openqa/selenium/SearchContext.class
Hi Anuja!
I am new in appium.Please can u tell me how to write 2 test cases in android studio using TestNg and how to creat testng.xml file.Please suggest me
How to fix this error:
Error:Execution failed for task ':app:transformClassesWithJarMergingForDebug'.
> com.android.build.api.transform.TransformException: java.util.zip.ZipException: duplicate entry: org/openqa/selenium/SearchContext.class
How to fix this error:
Error:Gradle: Execution failed for task ':app:transformClassesWithJarMergingForDebug'.
> com.android.build.api.transform.TransformException: java.util.zip.ZipException: duplicate entry: org/openqa/selenium/SearchContext.class
Did you find solution for this error?
Soled this error.
I added the selenium jars with standalone server(following more than 1 tutorials for config!), so as it was something about duplication, I commented all the jars of selenium and only kept standalone server in build.gradle. This solved my issue. | http://www.qaautomated.com/2016/03/appium-setup-in-android-studio-with.html | CC-MAIN-2018-51 | en | refinedweb |
Patching and Upgrading Guide
For Use with Red Hat JBoss Enterprise Application Platform 7.1
Abstract
Chapter 1. Introduction
1.1. About Migrations and Upgrades
Major Upgrades
A major upgrade or migration is required when an application is moved from one major release to another, for example, from JBoss EAP 6.4 to JBoss EAP 7.0. If an application follows the Java EE specifications, does not access deprecated APIs, and does not contain proprietary code, it might be possible to run the application in JBoss EAP 7 without any application code changes. However, the server configuration has changed in JBoss EAP 7 and requires migration. This type of migration is addressed in the JBoss EAP Migration Guide.
Minor Updates
JBoss EAP periodically provides point releases, which are minor updates that include bug fixes, security fixes, and new features. Information about the changes made in a point release are documented in the JBoss EAP Migration Guide and in the 7.1.0 Release Notes.
You can use the JBoss Server Migration Tool to automatically upgrade from one point release to another, for example from JBoss EAP 7.0 to JBoss EAP 7.1. For information about how to configure and run the tool, see Using the JBoss Server Migration Tool.
If you prefer, you can perform a manual upgrade of the server configuration. Instructions on how to perform a manual upgrade are documented in this guide. For more information, see Upgrading JBoss EAP.
Cumulative Patches
JBoss EAP also periodically provides cumulative patches that contain bug and security fixes. Cumulative patches increment the release by the last digit, for example from 7.1.0 to 7.1.1. Patch installation is addressed in the Patching JBoss EAP chapter of this guide.
1.2. Subscribing to Security Announcements
Red Hat maintains a mailing list for security announcements. You can subscribe to this mailing list to be notified of security-related announcements that affect JBoss EAP.
Chapter 2. Patching JBoss EAP
The method of applying a patch to JBoss EAP depends on your installation method. If you installed JBoss EAP using the ZIP or installer methods, you must use the ZIP-based patch management system. If you used RPMs to install JBoss EAP on Red Hat Enterprise Linux, you must use RPM patches.
Before applying or rolling back a patch, you should back up your JBoss EAP server, including all deployments and configuration files.
If you have a locally installed JBoss EAP Maven repository, you must also patch the Maven repository to the same cumulative patch version as your JBoss EAP server.
2.1. Patching a ZIP/Installer Installation
Cumulative patches for a ZIP or Installer installation of JBoss EAP are available to download from the Red Hat Customer Portal.
For multiple JBoss EAP hosts in a managed domain environment, individual hosts can be patched from your JBoss EAP domain controller.
In addition to applying a patch, you can also roll back the application of a patch.
2.1.1. Important Notes on ZIP/Installer Installation Patching
- If you apply a patch that updates a module, the new patched JARs that are used at runtime are stored in
EAP_HOME/modules/system/layers/base/.overlays/PATCH_ID/MODULE. The original unpatched files are left in
EAP_HOME/modules/system/layers/base/MODULE, but these JARs are not used at runtime.
In order to significantly decrease the size of cumulative patch releases for JBoss EAP 7, you now cannot perform a partial roll back of a cumulative patch. For a patch that has been applied, you will only be able to roll back the whole patch.
For example, if you apply CP03 to JBoss EAP 7.0.0, you will not be able to roll back to CP01 or CP02. If you would like the ability to roll back to each cumulative patch release, each cumulative patch must be applied separately in the order they were released.
2.1.2. Applying a Patch
JBoss EAP servers that have been installed using the RPM method cannot be updated using these instructions. See the RPM instructions for applying a patch instead.
You can apply downloaded patches to a JBoss EAP server using either the management CLI or the management console.
Applying a Patch to JBoss EAP Using the Management CLI
- Log in to the Red Hat Customer Portal, and download the patch file from JBoss EAP Software Downloads.
From the management CLI, apply the patch using the following command, including the appropriate path to the patch file:
patch apply /path/to/downloaded-patch.zipNote
To patch another JBoss EAP host in a managed domain, you can specify the JBoss EAP host name using the
--host=argument. For example:
patch apply /path/to/downloaded-patch.zip --host=my-host
The patch tool will warn if there are any conflicts in attempting to apply the patch. If there are conflicts, enter
patch --helpfor the available arguments to re-run the command with an argument specifying how to resolve the conflicts.
Restart the JBoss EAP server for the patch to take effect:
shutdown --restart=true
Applying a Patch to JBoss EAP Using the Management Console
- Log in to the Red Hat Customer Portal, and download the patch file from JBoss EAP Software Downloads.
Open the management console and navigate to the Patch Management view.
For a standalone server, click the Patching tab.
Figure 2.1. The Patch Management Screen for a Standalone Server
For a server in a managed domain, click the Patching tab, then select the host that you want to patch from the table, and click View.
Figure 2.2. The Patch Management Screen for a Managed Domain
Click Apply a New Patch.
- If you are patching a managed domain host, on the next screen select whether to shutdown the servers on the host, and click Next.
Click the Browse button, select the downloaded patch you want to apply, and then click Next.
Figure 2.3. Apply Patch Screen
- If there are any conflicts in attempting to apply the patch, a warning will be displayed. Click View error details to see the detail of the conflicts. If there is a conflict, you can either cancel the operation, or select the Override all conflicts check box and click Next. Overriding conflicts will result in the content of the patch overriding any user modifications.
- After the patch has been successfully applied, select whether to restart JBoss EAP now for the patch to take effect, and click Finish.
2.1.3. Rolling Back a Patch
You can roll back a previously applied JBoss EAP patch using either the management CLI or the management console.
Rolling back a patch using the patch management system is not intended as a general uninstall functionality. It is only intended to be used immediately after the application of a patch that had undesirable effects.
Prerequisites
- A patch that was previously applied.
When following either procedure, use caution when specifying the value of the
Reset Configuration option:
If set to
TRUE, the patch rollback process will also roll back the JBoss EAP server configuration files to their pre-patch state. Any changes that were made to the JBoss EAP server configuration files after the patch was applied will be lost.
If set to
FALSE, the server configuration files will not be rolled back. In this situation, it is possible that the server will not start after the rollback, as the patch may have altered configurations, such as namespaces, which may no longer be valid and will have to be fixed manually.
Rolling Back a Patch Using the Management CLI
From the management CLI, use the
patch historycommand to find the ID of the patch that you want to roll back.Note
If you are using a managed domain, you must add the
--host=HOSTNAMEargument to the commands in this procedure to specify the JBoss EAP host.
Roll back the patch with the appropriate patch ID from the previous step.
patch rollback --patch-id=PATCH_ID --reset-configuration=TRUE
The patch tool will warn if there are any conflicts in attempting to roll back the patch. If there are conflicts, enter
patch --helpfor the available arguments to re-run the command with an argument specifying how to resolve the conflicts.
Restart the JBoss EAP server for the patch roll back to take effect:
shutdown --restart=true
Rolling Back a Patch Using the Management Console
Open the management console and navigate to the Patch Management view.
- For a standalone server, click the Patching tab.
- For a server in a managed domain, click the Patching tab, then select the host that you want to patch from the table, and click View.
Select the patch that you want to rollback from those listed in the table, then click Rollback.
Figure 2.4. Recent Patch History Screen
- If you are rolling back a patch on a managed domain host, on the next screen select whether to shutdown the servers on the host, and click Next.
Choose your options for the rollback process, then click Next.
Figure 2.5. Patch Rollback Options
Confirm the options and the patch to be rolled back, then click Next.
- If there are any conflicts in attempting to rollback the patch and the Override all option was not selected, a warning will be displayed. Click View error details to see the detail of the conflicts. If there is a conflict, you can either cancel the operation, or click Choose Options and try the operation again with the Override all check box selected. Overriding conflicts will result in the rollback operation overriding any user modifications.
- After the patch has been successfully rolled back, select whether to restart the JBoss EAP server now for the changes to take effect, and click Finish.
2.1.4. Clearing Patch History
When patches are applied to a JBoss EAP server, the content and history of the patches are preserved for use in rollback operations. If multiple cumulative patches are applied, the patch history may use a significant amount of disk space.
You can use the following management CLI command to remove all older patches that are not currently in use. When using this command, only the latest cumulative patch is preserved along with the GA release. This is only useful for freeing space if multiple cumulative patches have previously been applied.
/core-service=patching:ageout-history
If you clear the patch history, you will not be able to roll back a previously applied patch.
2.2. Patching an RPM Installation
Prerequisites
- Ensure that the base operating system is up to date, and is subscribed and enabled to get updates from the standard Red Hat Enterprise Linux repositories.
Ensure that you are subscribed to the relevant JBoss EAP repository for the update.Warning
When updating an RPM installation, JBoss EAP is updated cumulatively with all RPM-released fixes for the subscribed repository.
If you are subscribed to the
currentrepository, this may mean that your installation will also be upgraded to the next available minor release. For more details, see the information on choosing a JBoss EAP repository in the Installation Guide.
- Back up all configuration files, deployments, and user data.
For a managed domain, the JBoss EAP domain controller should be updated first.
To install a JBoss EAP patch via RPM from your subscribed repository, update your Red Hat Enterprise Linux system using the following command:
# yum update
2.3. Optional: Patch a Local JBoss EAP Maven Repository
If you have installed the JBoss EAP Maven repository, it may also need to be patched.
The JBoss EAP Maven repository is available online or as a downloaded ZIP file. If you use the publicly hosted online Maven repository, updates are automatically applied, and no action is required to update it. However, if you installed the Maven repository locally using the ZIP file, you are responsible for applying updates to the repository.
Whenever a cumulative patch is released for JBoss EAP, a corresponding patch is provided for the JBoss EAP Maven repository. This patch is available in the form of an incremental ZIP file that is unzipped into the existing local repository. It does not overwrite or remove any existing files, so there is no rollback requirement.
Use the following procedure to apply updates to your locally installed JBoss EAP Maven repository.
Prerequisites
- Valid access and subscription to the Red Hat Customer Portal.
- The JBoss EAP 7.1 Maven repository, previously downloaded and installed locally.
Update a Locally Installed JBoss EAP Maven Repository
- Open a browser and log into the Red Hat Customer Portal.
- Select Downloads from the menu at the top of the page.
- Find
Red Hat JBoss Enterprise Application Platformin the list and click on it.
- Select the correct version of JBoss EAP from the Version drop-down menu, then click on Patches tab.
- Find
Red Hat JBoss Enterprise Application Platform 7.1 Update CP_NUMBER Incremental Maven Repositoryin the list, where
CP_NUMBERis the cumulative patch number you want to update to, and then click Download.
- Locate the path to your JBoss EAP Maven repository. This is referred to in the commands below as
EAP_MAVEN_REPOSITORY_PATH.
Unzip the downloaded Maven patch file directly into the directory of the JBoss EAP 7.1 Maven repository.
For Red Hat Enterprise Linux, open a terminal and run the following command, replacing the values for the cumulative patch number and your Maven repository path.
$ unzip -o jboss-eap-7.1.CP_NUMBER-incremental-maven-repository.zip -d EAP_MAVEN_REPOSITORY_PATH
- For Microsoft Windows, use the Windows extraction utility to extract the ZIP file into the root of the
EAP_MAVEN_REPOSITORY_PATHdirectory.
Chapter will still be applicable after the upgrade. thanJ-10-11 12:33:03 UTC | https://access.redhat.com/documentation/en-us/red_hat_jboss_enterprise_application_platform/7.1/html-single/patching_and_upgrading_guide/ | CC-MAIN-2018-51 | en | refinedweb |
More on deconstruction in C# 7
February 9, 2018 Leave a comment
We looked at deconstruction using the new ValueTuple type in this post. This short post only shows a couple more bits and pieces related to object deconstruction in C# 7.
Consider the following Rectangle class:
public class Rectangle { public int Width { get; set; } public int Height { get; set; } }
Let’s see if we can collect the Width and Height properties into a tuple: | https://dotnetcodr.com/tag/deconstruction/ | CC-MAIN-2018-51 | en | refinedweb |
This page uses content from Wikipedia and is licensed under CC BY-SA...
There are many reasons why you might wish to move a page:
Technical restrictions prevent the storage of titles beginning with a lowercase letter, containing certain characters, and using formatting such as italics. Templates which may be used as workarounds include:
Consider listing pages that you want to have renamed/moved at Wikipedia:Requested moves. List them at Wikipedia:Requested moves/Technical requests, if:
For other cases, follow the instructions for controversial and potentially controversial moves: pagemove situation which is blocked by history at the target of the move, list the page at Wikipedia:Requested moves/Technical requests following the listing procedure outlined there.).:
Pages in the category namespace can be moved, but).
Since the article name is reflected in the lead section, that section may need to be updated to be consistent with the new name. Along with generic lead corrections, add appropriate hatnotes where appropriate to affected pages..
Redirects to redirects, a.k.a. Double redirects, aren't automatically followed (this prevents infinite loops and spaghetti linking). Note: don't fix double redirects if you think your move might be controversial and be reverted..
Redirects should be categorized per the WikiProject Redirect style guide.
Check to see if there are any interlanguage links. Usually, with a page move, the Wikidata for the associated item is automatically updated. If necessary, update it using the "Edit links" link at the bottom of the list of links..
Usually, the move discussion has a
{{requested move/dated}} tag. Follow the instructions given in the tag to inform RMCD bot (talk · contribs) that the discussion is closed.
Some archiving bots have hardcoded page names in their archiving settings. After closing the move and moving the talk page archiving, the bot settings should be updated on the talk page to the new name of the talk page. In some circumstances, this will involve updating (moving) a hard-coded bot subpage., move the intended page to the location, and).
If the new title exists but is a redirect to the old title with a single line in the page history, then you can rename the page..
Requests for moves over redirects can be posted at Wikipedia:Requested moves.
If a redirect has more than just one line in the page history but still a minor edit history, file a technical move request at Wikipedia:Requested moves/Technical requests using
{{subst:RMassist|current page name|new page name|reason = reason for move}} (using the format outlined at the page there)..
Unregistered users and new users who are not yet autoconfirmed cannot move any pages. With a few exceptions, autoconfirmed users have the technical ability to move any page. implicitly protected from moves..:
{{rename media|new name|reason}}on the page of the file and a file mover or administrator will move the file if it conforms to the guidelines.
For more information about appropriate names for pages in the file namespace, see Wikipedia:File names.
Avoid moving a page while the edit box of the corresponding Talk page is open: when you hit "Publish..
To undo a move from page A to page B, simply move page B back to page A. But if someone intervened to the A→B redirect, then the move cannot be fixed without special privileges.
Note that user moved page A to page B and then to page C, you cannot simply move C to A. If a bot has not "fixed" the double A→B redirect yet (see above), then you have to:
If page A has subsequently been edited, or the move software is behaving weirdly, only an admin can sort things list it at 'redirects for discussion'), or (administrators only) just delete it.
There are two methods to swap pages A and B, preserving history.
Classic sequence
Improved sequence:CSD#G6. Help with this task can be found at Wikipedia:Requested moves.
The same sequences, but with only two moves, can be used for half-swapping (chain shifting) two pages (such that A would become C and B would become A). pages. In some circumstances, administrators can fix this by merging page histories. If you find a cut-and-paste move that needs to be fixed, please follow the instructions at Wikipedia:Requests for history merge to have an administrator take care of the problem.
The terms "rename" and "move" mean the same in this context. They just refer to different models for picturing the operation:
Since the system marks the page with the old name as".
"Rename" may have other meanings on Wikipedia. See Help:Rename.ipedia.org/w/index.php?title=User:Plastikspork/massmove.js&action=raw&ctype=text/javascript' ); //[[User:Plastikspork/massmove.js]] mw.util.addPortletLink("p-tb", "//en.wikipedia.org/wiki/Special:Massmove", "Mass move", "p-massmove", "Mass move"); | https://readtiger.com/wkp/en/Wikipedia:Moving_a_page | CC-MAIN-2018-51 | en | refinedweb |
I wrote a simple class in Python2.7 that should use the
@property functionality.
class c(): def __init__(self): __pro = 1 @property def pro(self): return __pro *10 def setpro(self, x): __pro = x
Now when I create an object from this class and try to access the
pro property, I get the following error:
>>> x = c() >>> x.pro Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 7, in pro NameError: global name '_c__pro' is not defined
Note that the whole thing was written inside the same python commandline-session, so it should have nothing to do with missing imports or wrong import namespaces.
What am I doing wrong here? How must I rewrite it to access the property
pro? | http://www.howtobuildsoftware.com/index.php/how-do/eZG/python-python-27-oop-properties-encapsulation-python-27-property-usage-results-in-error-global-name-c-pro-is-not-defined | CC-MAIN-2018-51 | en | refinedweb |
Fl_Widget
|
+----Fl_Box, Fl_Browser_, Fl_Button, Fl_Chart, Fl_Clock_Output,
Fl_Free, Fl_Group, Fl_Input_, Fl_Menu_, Fl_Positioner,
Fl_Progress, Fl_Timer, Fl_Valuator
#include <FL/Fl_Widget.H>
All "property" accessing methods, such as color(),
parent(), or argument() are implemented as trivial inline
functions and thus are as fast and small as accessing fields in a
structure. Unless otherwise noted, the property setting methods such as
color(n) or label(s) are also trivial inline functions,
even if they change the widget's appearance. It is up to the user code
to call redraw() after these.
Creates a widget at the given position and size. The
Fl_Widget is a protected constructor, but all derived
widgets have a matching public constructor. It takes a value for
x(), y(), w(), h(), and an
optional value for label().
Destroys the widget. Destroying single widgets is not very
common, and it is your responsibility to either
remove() them from any enclosing group or destroy that
group immediately after destroying the children. You
almost always want to destroy the parent group instead which
will destroy all of the child widgets and groups in that group.
Fl_Widget::active() returns whether the widget is
active. Fl_Widget::active_r() returns whether the
widget and all of its parents are active._ACTIVATE or
FL_DEACTIVATE to the widget if active_r() is true.
Currently you cannot deactivate Fl_Window widgets.
Gets or sets the label alignment, which controls how the
label is displayed next to or inside the widget. The default
value is FL_ALIGN_CENTER, which centers the label
inside the widget. The value can be any of these constants
bitwise-OR'd together:
Gets or sets the current user data (long) argument
that is passed to the callback function.
This is implemented by casting the long
value to a void * and may not be portable on
some machines.
Gets or sets the box type for the widget, which identifies a
routine that draws the background of the widget. See Box Types for the available
types. The default depends on the widget, but is usually
FL_NO_BOX or FL_UP_BOX.
Gets or sets the current callback function for the widget.
Each widget has a single callback.
Fl_Widget::changed() is a flag that is turned on
when the user changes the value stored in the widget. This is
only used by subclasses of Fl_Widget that store values,
but is in the base class so it is easier to scan all the widgets
in a panel and do_callback() on the changed ones in
response to an "OK" button.
Most widgets turn this flag off when they do the callback, and when
the program sets the stored value.
Hides the widget; you must still redraw the parent to see a
change in the window. Normally you want to use the hide() method instead.
hide()
Disables keyboard focus navigation with this widget;
normally, all widgets participate in keyboard focus navigation.
Gets or sets the background color of the widget. The color is
passed to the box routine. The color is either an index into an
internal table of RGB colors or an RGB color value generated
using fl_rgb_color(). The default for most widgets is
FL_BACKGROUND_COLOR. See the enumeration list for
predefined colors. Use Fl::set_color() to
redefine colors.
The two color form sets both the background and selection
colors. See the description of the selection_color()
method for more information.
Returns 1 if b is a child of this widget, or is
equal to this widget. Returns 0 if b is NULL.
Sets the current label. Unlike label(), this method
allocates a copy of the label string instead of using the
original string pointer.
The first version returns non-zero if draw() needs to be
called. The damage value is actually a bit field that the widget
subclass can use to figure out what parts to draw.
The last two forms set the damage bits for the widget; the
last form damages the widget within the specified bounding box.
The default callback, which puts a pointer to the widget on
the queue returned by Fl::readqueue(). You
may want to call this from your own callback.
Gets or sets the image to use as part of the widget label.
This image is used when drawing the widget in the inactive
state.
Causes a widget to invoke its callback function, optionally
with arbitrary arguments.
Handles the specified event. You normally don't call this
method directly, but instead let FLTK do it when the user
interacts with the widget.
When implemented in a new widget, this function must return 0
if the widget does not use the event or 1 if it uses the
event.
Gets or sets the image to use as part of the widget label.
This image is used when drawing the widget in the active state.
Returns 1 if this widget is a child of a, or is
equal to a. Returns 0 if a is NULL.
Get or set the current label pointer. The label is shown
somewhere on or next to the widget. The passed pointer is stored
unchanged in the widget (the string is not copied), so if
you need to set the label to a formatted value, make sure the
buffer is static, global, or allocated. The copy_label() method
can be used to make a copy of the label string
automatically.
Gets or sets the label color. The default color is FL_FOREGROUND_COLOR.
Gets or sets the font to use. Fonts are identified by small
8-bit indexes into a table. See the enumeration list for
predefined typefaces. The default value uses a Helvetica
typeface (Arial for Microsoft® Windows®). The function
Fl::set_font() can
define new typefaces.
Gets or sets the font size in pixels. The default size is 14
pixels.
Gets or sets the labeltype which
identifies the function that draws the label of the widget. This
is generally used for special effects such as embossing or for
using the label() pointer as another form of data such
as an icon. The value FL_NORMAL_LABEL prints the label
as plain text.
output() means the same as !active() except
it does not change how the widget is drawn. The widget will not
receive any events. This is useful for making scrollbars or
buttons that work as displays rather than input devices.
Returns a pointer to the parent widget. Usually this is a Fl_Group or Fl_Window. Returns
NULL if the widget has no parent.
Marks the widget as needing its draw() routine called.
Marks the widget or the parent as needing a redraw for the
label area of a widget.
Change extensiive calculations.
position(x,y) is a shortcut for resize(x,y,w(),h()),
and size(w,h) is a shortcut for resize(x(),y(),w,h).
Gets or sets the selection color, which is defined for Forms
compatibility and is usually used to color the widget when it is
selected, although some widgets use this color for other
purposes. You can set both colors at once with
color(a,b).
This is the same as (active() && !output()
&& visible()) but is faster.
Gets or sets a string of text to display in a popup tooltip
window when the user hovers the mouse over the widget. The
string is not copied, so make sure any formatted string
is stored in a static, global, or allocated buffer.
If no tooltip is set, the tooltip of the parent is inherited.
Setting a tooltip for a group and setting no tooltip for a child
will show the group's tooltip instead. To avoid this behavior,
you can set the child's tooltip to an empty string
("").
Returns the widget type value, which is used for Forms
compatability and to simulate RTTI.
Returns the position of the upper-left corner of the widget
in its enclosing Fl_Window (not its parent if that is not
an Fl_Window), and its width and height.
Gets or sets the current user data (void *) argument
that is passed to the callback function.
Returns a pointer to the primary Fl_Window widget.
Returns NULL if no window is associated with this
widget. Note: for an Fl_Window widget, this returns
its parent window (if any), not this window.
Makes the widget visible; you must still redraw the parent
widget to see a change in the window. Normally you want to use
the show() method
instead.
show()
Enables keyboard focus navigation with this widget; note,
however, that this will not necessarily mean that the widget
will accept focus, but for widgets that can accept focus, this
method enables it if it has been disabled.
An invisible widget never gets redrawn and does not get
events. The visible() method returns true if the
widget is set to be visible.The visible_r() method
returns true if the widget and all of its parents are visible. A
widget is only visible if visible() is true on it
and all of its parents.
Changing it will send FL_SHOW or FL_HIDE
events to the widget. Do not change it if the parent is not
visible, as this will send false FL_SHOW or FL_HIDE
events to the widget. redraw() is called if necessary on
this or the parent.
Modifies keyboard focus navigation.
See set_visible_focus() and
clear_visible_focus().
The second form returns non-zero if this widget will participate in keyboard focus navigation.
set_visible_focus()
clear_visible_focus()
Fl_Widget::when() is a set of bitflags used by
subclasses of Fl_Widget to decide when to do the
callback. If the value is zero then the callback is never
done. Other values are described in the individual widgets.
This field is in the base class so that you can scan a panel and
do_callback() on all the ones that don't do their own
callbacks in response to an "OK" button.
The effect of the align() function is not clear from just the names of the arguments. Pictures (or word pictures) are needed to explain what these names mean.
It is particularly unclear how these interact with an image drawn on the button, as adding an image makes the label move.
[ Reply ]
It is not documented what the second argument in this call is for:
void Fl_Widget::callback(Fl_Callback*, void* = 0)
I assume that it serves the same purpose as the user_data(void*) function, but there is no indication that this is true nor explanation of how the two might interact (does one take precedence?).
[ Reply ]
> I assume that it serves the same purpose as the user_data(void*)
Yes.
> does one take precedence?
Which ever method is called last takes precedence.
In other words, callback(foo,(void*)data) will stay in
effect until changed with user_data(newdata);
[ Reply ] | https://www.fltk.org/documentation.php/doc-1.1/Fl_Widget.html | CC-MAIN-2018-51 | en | refinedweb |
US9613076B2 - Storing state in a dynamic content routing network - Google PatentsStoring state in a dynamic content routing network Download PDF
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- Publication number
- US9613076B2US9613076B2 US13941131 US201313941131A US9613076B2 US 9613076 B2 US9613076 B2 US 9613076B2 US 13941131 US13941131 US 13941131 US 201313941131 A US201313941131 A US 201313941131A US 9613076 B2 US9613076 B2 US 9613076B2
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- Grant
- Patent type
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- Prior art keywords
- object
- client
- update message
- routing network
- related to U.S. patent application Ser. No. 11/515,366, filed Aug. 31, 2006, Ser. No. 10/213,269, filed Aug. 5, 2002, now U.S. Pat. No. 7,127,720, and Ser. No. 10/017,182, filed Dec. 14, 2001, now U.S. Pat. No. 7,043,525, and U.S. Provisional Application Nos. 60/256,613, filed Dec. 18, 2000, 60/276,847, filed Mar. 16, 2001, 60/278,303, filed Mar. 21, 2001, 60/279,608, filed Mar. 28, 2001, and 60/280,627, filed Mar. 29, 2001, all of which are hereby incorporated herein by reference.
Field
This disclosure pertains in general to transferring information through digital networks and in particular to storing the state of properties being updated by the transferred information.
Background
The Internet is a digital network of computers. An individual computer on the Internet is typically identified by an interne, apples,.
According to one embodiment, a non-transitory computer readable storage medium having instructions stored thereon for updating a property of a live object at a client, the instructions when executed causes a processor to perform operations including identifying the live object at the client. The operations further includes receiving an update message for the live object from an object state storage, where the object state storage is located on a dynamic content routing network, the update message is stored by an object ID associated with the live object, and the update message allowing the property to be updated for the live object at the client in real-time. The operations also include processing the update message.
According to another embodiment, a hardware-based dynamic content routing network includes means for maintaining mappings between clients and live objects using an object ID associated with the live objects. The dynamic content routing network further includes means for receiving an update message for an identified live object and means for routing the update message using the object ID associated with the live object to the clients according to the mappings.
According to another embodiment, a client module of an object state storage is configured to identify a live object at a client. The client module is further configured to receive an update message for the live object from storage, the update message is stored by an object ID associated with the live object, and the update message allowing the property to be updated for the live object at the client in real-time. The client module is further configured to transmit the update message for the live object to the client disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
The server 112, client 114, information provider 108, dynamic content provider 116, OSS 109, and routing network 110 are preferably in communication via conventional communications links 117 such as those comprising the Internet. The communications links 117 include known wired communications media, such as dedicated or shared data, cable television or telephone lines, and/or known wireless communications media, such as communications over the cellular telephone network using protocols such as the global system for mobile communications (GSM), code division multiple access (CDMA), time division multiple access (TDMA), etc.
In one embodiment, the entities may each be in communication with one or more Internet Service Providers (ISPs) (not shown) that provide each entity with access to other computers on the Internet. The addition, the server 112, client 114, information provider 108, dynamic content provider 116, OSS 109, and routing network 110 are preferably each identified by at least one Internet Protocol (IP) address such as “66.35.209.224.” The IP address may also have one or more domain names associated with it, such as “bangnetworks.com.” Alternative embodiments may use alternative addressing schemes and/or naming conventions instead of, or in addition to, those described herein. For example, embodiments wherein one or more of the clients are cellular telephones or other portable devices may rely on different addressing schemes.
Preferably, the information provider 108 provides web pages IDs. The routing network 110, in turn, preferably maintains a registry indicating which clients have registered for which object IDs.
The information provider 108 and/or dynamic content provider 116 send update messages to the routing network 110. These messages can be sent any time the information provider 108 or dynamic content provider 116 wants to update a property of a live object. Each update message preferably identifies a live object and contains data for updating a property of the identified live object. The routing network 110 accesses the registry and determines which clients have registered for the identified object. Then, the routing network 110 routes the update message to the appropriate clients. Upon receipt of an update message, the clients 114 update the specified property of the live.
The routing network 110 provides an efficient one-to-many mapping of objects to clients (and by inference of information, a many-to-many mapping of information providers 108/dynamic content providers 116 to clients) through object-based routing. Messages provided by the information provider 108 and/or dynamic content provider 116 to the routing network 110 are not routed to the clients 114 based entirely on a specified destination; more specifically, they are not routed based on the IP address of the client, as in conventional IP routing schemes. Instead, the messages are routed based on the live objects referenced by the message.
The mapping and object-based routing provided by the routing network 110 allow the information provider 108 and dynamic content provider 116 to update properties of live objects at a dynamically changing cross-section of clients in real-time, without requiring the information provider or dynamic content provider to track the clients or web pages being viewed by the clients. The clients 114, in turn, do not need to have any a priori knowledge of object IDs—they “discover” which IDs they should register when they receives the web pages 118 from the server 112.
Object-based routing also allows information providers 108 to dynamically update content on web pages without requiring the clients 114 to re-request the content, and without requiring the information providers 108 or servers 112 to maintain connections with the clients. In this manner, significantly more clients can receive updated content from a given information provider 108 than would be possible utilizing conventional client-side request-driven transmission control protocol/Internet Protocol (TCP/IP) connections between the clients and the server 112.
Turning now to the individual entities illustrated in
An information provider 108 is an entity providing one or more web pages 118, information contained in web pages, and/or other representations of data served by the server 112. The information provider 108 preferably has a conventional computer system coupled to the Internet. In one embodiment, the server 112 is directly controlled by the information provider 108 (e.g., the server is physically located at the information provider and/or is dedicated to serving only the information provider's web pages). In this embodiment, the server 112 and information provider 108 can be treated as the same entity. In an alternative embodiment, the server 112 serves web pages from multiple information providers.
As is known in the art, the web pages 118 and other content on the server 112 are specified by uniform resource locators (URLs) having the form “service://server/path/web page.” Typically, web pages 118 are obtained via the hypertext transport protocol (HTTP) and thus an exemplary URL for retrieving the web page “b1.html” from the web server having the domain name “” is “.”
As used herein, a “web page” is a block of data available from the server 112. In the simplest case, a web page is a file written in the hypertext markup language (HTML). The web page may also contain or refer to one or more other blocks of data, such as other files, text, images, applets, video, and/or audio. In addition, the web page may contain instructions for presenting the web page and its content, such as HTML tags and style sheets. The instructions may also be in the Extensible Markup Language (XML), which is related to HTML and adds semantic content to web pages or the Dynamic HTML (DHTML), which adds some dynamic content to web pages. Additionally, the instructions may take the form of one or more programs such as JAVA® applets and JAVASCRIPT® and/or DHTML scripts.
As used herein, the phrase “web page” also refers to other representations of data served by the server 112 regardless of whether these data representations include characteristics of conventional web pages. These data representations include, for example, application programs and data intended for the web browser 120 or other application programs residing at the clients 114 or elsewhere, such as spreadsheet or textual (e.g., word processing) data, etc.
In a preferred embodiment, objects at the client, such as web pages and elements of web pages, can be designated as “live” by the information provider 108. Properties of a live object can be dynamically updated in real-time at the client 114 by the information provider 108 or another entity acting on behalf of the information provider. As used herein, an “object” is any datum or data at the client 114 that can be individually identified or accessed. Examples of objects include elements of web pages such as text characters and strings, images, frames, tables, audio, video, applets, scripts, HTML, XML, and other code forming the web page, variables and other information used by applets, scripts and/or code, URLs embedded in the web page, etc. Application and operating system constructs are also objects. For example, cells of spreadsheets, text in word processor documents, and title bars and messages displayed by the operating system or applications are objects. Preferably, multiple objects can be grouped together into a single, logical object. Thus, an object can be defined at any desired or useful level of granularity.
Since content on a web page is conceptualized and organized by “object,” the present disclosure essentially abstracts web pages and web page content, and other modules and/or functionality at the client 114, away from the HTML code or other conventional representation. This abstraction allows the information provider 108 to update a property of an object without concern for the location, display format, or other specifics of how the data is being represented at the client 114.
Live objects have associated “properties” which include any modifiable data related to the object or referenced with respect to the object. The properties may or may not affect the visual representation of the object in the web page or other data representation. A property may affect an internal aspect of the object and, thus, a change to the property may not have any direct effect on a web page containing the object. For example, the property may affect whether particular aspects of the object are modifiable, how the object responds to user input or other stimuli, etc. Additionally, a property may also have a direct effect on how the object is displayed at the client 114. For example, the property may affect the content, color, typeface, size, formatting, or other attribute of text, images, or other data displayed by the object. Other properties may occupy parts of the spectrum between having no effect on the visible representation of the object and having a direct effect on the visible representation of the object. For example, a web page showing scores of football games may include a list of games and the current scores of the games as of the time the server 112 serves the web page. The list of games, subset of games to be displayed, and the scores of the games can be designated as live objects (or properties of a single live object) and updated as necessary or desired.
A property can also preferably include instantiating an instance of the object or invoking functionality of the object. For example, a property of a browser window object may include functionality for instantiating another browser window. This function can be invoked as a logical change to a property of the object. The second browser window can be referenced through the original browser window (i.e., object) or designated as a new live object.
An information provider 108 or other entity preferably updates a live object at a client 114 via an update message. In general, an update message identifies the live object and, if necessary, the property of the live object, and contains data for updating the property. In one embodiment, the data may be the actual value for the property or executable code for causing the object's property to be updated. For example, the data may be a simple numerical or textual value, e.g., “4,” to which the property should be set, and/or the data may be JAVASCRIPT® code or a call to a JAVASCRIPT® function at the client that effects the desired change to the property of the object.
The update message preferably implicitly or explicitly identifies a handler at the client 114 for use in updating the live object's property. In one embodiment, the client 114 utilizes a default handler when the message implicitly specifies the handler (e.g. when the message does not identify a specific handler). In one embodiment, if the update message specifies the actual value for the property, a default handler generates JAVASCRIPT® code for changing the property to the specified value. If the data in the update message are JAVASCRIPT® code, the default handler does not perform any processing of the code. In either case, the default handlers preferably use LiveConnect to execute the JAVASCRIPT® code in a Java Virtual Machine (JVM) 122 at the client 114 and thereby update the property of the live object.
For certain objects and/or data types, the default handlers are not appropriate. In these cases, the message preferably explicitly identifies a handler for performing the update. For example, the message may explicitly specify a function to call on the data or the message may explicitly identify the environment in which the data should be executed. For example, the data in the update message may include code for execution by a software “plug-in” such as MACROMEDIA FLASH® and the message may explicitly identify FLASH as the handler.
The information provider 108 preferably designates an object as “live” by including a unique identifier for the object, the object ID, in the web page or other data representation provided to the client 114. In one embodiment, the information provider 108 encodes the object ID in an objects corresponding HTML “ID” attribute using the following HTML expression:
ID=“elementIdentifier,”
where “elementIdentifier” is the object ID and is preferably a string. The string can encode any information desired by the information provider 108 or other entity establishing the object ID and in one embodiment is a simple textual and/or numeric identifier. In one embodiment, the information provider 108 begins the object ID with a predefined token, such as “Bang$,” in order to distinguish live objects from other objects that happen to have defined ID attributes. For example, an object can have the object ID “Bang$elementIdentifier.”
In the preferred embodiment, each information provider 108 optionally encodes a unique information provider ID in its object IDs in order to prevent naming collisions between the object IDs of different information providers. In one embodiment, the information provider ID is a textual and/or numeric identifier. The information provider 108 may specify the information provider ID and the object ID as part of a hierarchical namespace. For example, in one embodiment objects are named as follows: “$namespace1$[namespace2$ . . . . $namespaceN$]objectid,” where “$namespace1” is the information provider ID and the “$” operates as the name separator and defines additional optional levels of a namespace hierarchy. One embodiment of the system 100 supports typical directory services functionality. For example, two dollar sign characters appearing together. “$$,” refers to the top level of the namespace hierarchy.
Thus, the object ID for a live object is preferably formed from a combination of the predefined token, the information provider ID namespace, and a value assigned by the information provider 108. For example, the object ID for a live object representing the real time price of a stock having the symbol “BANG” might be: “Bang$$informationProviderID$equities$realtime$bang.” In this example, “Bang$” is the predefined token that signifies a live object, “$informationProviderID” is the ID identifying the information provider, “$equities$realtime$” defines levels of a namespace hierarchy, and “bang” identifies the specific object.
In some embodiments and situations, the object ID utilizes relative names. For example, an information provider 108 referring to its own object IDs is implicitly in its own namespace. Accordingly, the information provider 108 does not need to include the information Provider ID in the object IDs it utilizes internally. In one embodiment, the information provider ID is not explicitly encoded into the object ID. Instead, the information provider ID is encoded elsewhere in the web page in order to provide scope to the page's object IDs.
In one embodiment, the object ID identifies a point (i.e., a node in a tree) in a Document Object Model (DOM) representation of a web page or other document at the client 114. The DOM is a platform- and language-neutral interface that represents a document as a hierarchy of objects. The DOM also provides an interface that allows programs and scripts to dynamically access and update properties of the objects. Object properties can be inherited by descendent objects.
In this embodiment, the client 114 preferably executes an update message in the context of the specified point in the DOM representation. The update may specify a change to a property of the object at the identified point. The update also may specify a change to a parent or descendent of the object at the identified point. In each case, the update is executed relative to the specified point in the DOM representation. In one embodiment, points in the DOM representation specify how to update properties of live objects located at those points. Thus, the same update may be interpreted differently depending upon the identified live object's location in the DOM representation.
For example, assume there is an object in the DOM representation identified as “window.document.frame[3].ObjectID.” Also assume that the object has an “innerText” property located at “window.document.frame[3].ObjectID.innerText” that specifies the text displayed by the object. An update message can change the text displayed by the object by specifying “ObjectID” and the new value for the innerText property.
An advantage of utilizing object IDs to specify objects is that the information provider 108 or other entity providing the update message can access and change properties of objects without knowing the object's actual location in the DOM representation. Indeed, the object may be in different locations in different DOM representations and/or in multiple locations in the same DOM representation. In any of these cases, the update message will change the specified properties of all of the objects having the given object ID.
Depending upon the particular embodiment of the environment 100, the information provider 108 and/or the dynamic content provider 116 provides update messages to the routing network 110 and, optionally, to the OSS 109. The dynamic content provider 116 is preferably a conventional computer system operated by an entity that provides real-time information, such as stock prices and/or sports scores. In one embodiment, the information provider 108 receives updated properties for the live objects from the dynamic content provider 116 or another source (or generates the updated properties internally). Then, the information provider 108 sends an update message specifying the object ID and the change to the object property to the routing network 110 and OSS 109. In this embodiment, the dynamic content provider 116 may be absent from the environment 100.
In another embodiment, the dynamic content provider 116 provides the object IDs for live objects to one or more information providers 108 and the information providers 108 distribute the live objects, to the clients 114. Then, the dynamic content provider 116 sends messages specifying the changes to the properties of the live objects to the routing network 110 and OSS 109. For example, the dynamic content provider 116 distributes an object ID associated with the score of a particular baseball game to the information providers 108. Then, the dynamic content provider 116 sends a message specifying the object ID and an update to a property of the object that controls the displayed score of the particular baseball game to the routing network 110 pages 118 and/or other information from the server 112. In one embodiment, the client 114 is a conventional personal computer used by a person to access information on the Internet. In alternative embodiments, the client 114 is a different consumer electronic device having Internet connectivity, such as an Internet-enabled television, a cellular telephone, a personal digital assistant (PDA), a web browsing appliance, etc. The client 114 preferably, but not necessarily, has an associated display device.
The client 114 preferably executes a web browser 120, such as MICROSOFT INTERNET EXPLORER®, for retrieving web pages and displaying them on the display device. In embodiments where the client receives data representations from the server 112 other than conventional web pages, the web browser 120 does not necessarily share similarities with conventional web browsers. Preferably, the web browser 120 contains a JVM 122 for executing JAVA® applets and/or scripts. The web browser 120 also preferably contains Dynamic HTML capabilities, such as support for JAVASCRIPT® (or another scripting language, such as VBScript) and the Document Object Model (DOM), and enables communications between JAVA® and the scripting languages. In one embodiment, the web browser 120 supports the LiveConnect standard for enabling communication between JAVA® applets and scripts written in the supported scripting languages. The web browser 120 can also be extended through software plug-ins such as MACROMEDIA FLASH®, REAL NETWORKS REALPLAYER®, and/or APPLE QUICKTIME®. In alternative embodiments, the functionality of the JVM 122 and/or other aspects of the web browser 120 are provided by one or more other functional units within the client 114. The term “module” is used herein to refer to software computer program code and/or any hardware or circuitry utilized to provide the functionality attributed to the module. The web browser 120 and JVM 122 are examples of modules in the client 114.
In some embodiments, the client 114 does not necessarily have a display device, web browser 120 and/or other components associated with a typical consumer device. The client 114, for example, may be a dedicated purpose device having certain aspects of web connectivity such as an embedded HTTP client in a web-enabled appliance or in a controller for an automobile, audio-visual equipment, or some other device.
A web page 118 provided from the server 112 to the client 114 preferably includes instructions for enabling the live objects on the web page. The instructions cause the client 114 to automatically and transparently (i.e., without user interaction) contact the routing network 110 and download an activation module 124 for activating the live objects. In one embodiment, the instructions comprise a URL specifying the location of the activation module 124 at the routing network 110. In an alternative embodiment, the client 114 obtains the activation module 124 from the server 112 or another source.
The activation module 124 preferably contains JAVA® instructions for execution by the JVM 122. However, alternative embodiments of the module 124 may encode the instructions in the web page 118 and/or the activation module 124 using different languages and/or techniques. For example, the instructions and/or activation module 124 can be embedded in the web browser 120 or operating system, either as native code or as plug-ins. In these alternative embodiments, the web browser 120 does not have to download the activation module 124 from an external source.
The activation module 124 preferably 114 does not contact the OSS 109 to obtain the initial properties, but does register the object IDs with the routing network 110 as described above. The routing network 110, upon receiving new registrations from the client 114, contacts the OSS 109 in order to obtain the current update messages for the registered for objects. Then, the routing network 110 provides the update messages to the client 114 an update message to the routing network 110 in order to change a property of a live object at the client 114. In one embodiment, the message from the input source 210 to the routing network 110 contains only a single object ID and an update to a property of the identified object. In another embodiment, the message contains multiple object IDs and the corresponding property updates. In this latter embodiment, the message may have an associated “Batch ID” that identifies the message as having multiple object IDs and updates. Preferably, the information provider 108 can include a batch ID in a. In fact, the batch ID can be the same as the object ID so that the client 114 registers for both batch and non-batch messages by registering one ID. Alternatively, separate procedures can be established for registering batch messages. The client 114 preferably processes the component messages of a batch as if each message were delivered separately.
The routing network 110, in turn, routes 226 the message to each client 114 that has registered for the specified object ID, preferably by utilizing standard Internet communications protocols, such as IP addresses, etc. The activation module 124 at the client 114 processes the message and updates 228 the property of the identified live object. If live objects having the same object ID appear in multiple locations at the client 114 (e.g., at multiple locations on a web page being displayed at the client), the activation module 124 preferably updates each of the live objects having the specified ID. As a result, the routing network 110 allows live objects at the client 114 to be dynamically updated. Preferably, this routing and updating happens quickly enough to be considered “real-time” for the purposes of the input source 210..
There are various ways to internally represent the games and scores in the web pages using live objects. In one embodiment, a “game” object is defined having properties for the two teams involved in the game and the score associated with each team. The game object is placed at a selected position in the web page and the properties of the object cause the information about the game to be displayed on the page. In another embodiment, “team” and “score” objects are defined, with the team object having a property defining the name of a team and the score object having a property defining a score. In this second embodiment, the team and score objects are placed at selected locations on the page so that the proper teams and scores are aligned when the page is rendered. In yet another embodiment, an object is defined having properties for the name of one team and a score associated with that team. Then, pairs of the objects are placed in the page in the proper alignment to indicate the games and scores. In another embodiment, an object is defined having properties specifying names of two teams and a separate object is defined having properties specifying two scores. In this last embodiment, the two objects are placed in the page so that the names of the teams align with the associated scores. Obviously, additional variations of these representations are possible.
Assume for the example of
Thus, the same scores object 416 is utilized in different positions in each web page 410, 412. In order to update the score of the San Francisco 49ers vs. St. Louis Rams football game on both web pages, the input source 210 simply sends an update message to the routing network 110 specifying the object ID for the scores object 416 and the update to the score property. The routing network 110 routes the update message to the appropriate clients 114, and the clients update the appropriate score regardless of the particular page layout.
The input source 210, i.e., the information provider 108 and/or dynamic content provider 116 can use a variety of tools to generate the update messages.
Preferably, the tools allow the input source 210 to access an application programming interface (API) provided by the routing network 110 for accepting messages. In one embodiment, the messages sent by the input source 210 are in the same format as utilized by the activation module 124 at the client 114. In an alternative embodiment, the messages provided to the routing network 110 are in a different format and the routing network translates the messages into the format utilized by the activation module 124.
In one embodiment, the input source 210 utilizes a data pump module 510 to access the API. The data pump module 510 reads an extensible markup language (XML) file containing one or more object IDs and the new values for the identified objects at regular intervals and automatically generates API calls that send messages representing changes to object properties to the routing network 110. In another embodiment, the data pump module 510 is event-driven and reads the XML file in response to a change in the file or some other occurrence.
In another embodiment, the input source 210 utilizes a director console module 512 to access the API. Preferably, the director console module 512 presents an administrator with a graphical interface displaying the contents of the web page 118. For example, the administrator may use the director console 512 to edit textual data, images, and/or any objects or properties of objects on the web page. After editing, the administrator uses a “send update” button or similar technique to cause the director console module 512 to send messages for the changed objects and properties to the routing network 110 via the API.
In another embodiment, the information provider 108 and dynamic content provider 116 work together as the input source 210 by using a content management system module 514 to access the API. Preferably, the content management system module 514 resides at the information provider 108 and receives object property updates from the dynamic content provider 116. The content management system module 514 preferably updates the properties of the live objects in the web page 118 stored at the server 112 and also sends messages for the changed properties to the routing network 110. In this manner, the web page 118 at the server 112 and the web page displayed at the client 114 are updated almost simultaneously. In one embodiment, the dynamic content provider 116 sends the update messages to the routing network 110 instead of to the information provider 108. Embodiments of the system 100 can also utilize any combination of the content management techniques described herein.
For example, the tools described above can generate a message having the following code for updating the text displayed by a score object to “2”:
- LiveObject score=new LiveObject(“Bang$homeScoreID”); score.setProperty(“innerText”, “2”)
This code sets the innerText property of the object having object ID “Bang$homeScoreID” to “2.” The tools use the API to pass this message to the routing network 110.
Turning now to the actions performed at the client 114,
The activation module 124 preferably parses 610 the web page 118 received from the server 112 and identifies the object IDs of the live objects. In an alternative embodiment, the activation module 124 identifies only a subset of the object IDs, such as the IDs of only live objects that are currently being displayed by the web browser 120. Alternatively, a list of object IDs may be pre-encoded in the web page in addition to the objects themselves, thereby enabling easy identification by the activation module 124. In yet another embodiment, a user of the client 114 selects the object IDs to register.
The activation module 124 preferably opens 611 a connection between the client 114 and the OSS 109 (or routing network 110, depending upon the embodiment). In some cases, the client 114 is located behind a firewall that puts a restriction on the types of connection requests the client can make. A firewall might, for example, block all non-HTTP traffic. For this reason, the activation module 124 preferably wraps the connection request in an HTTP header in order to get the request through the firewall. The activation module 124 uses the connection to send the OSS 109 a vector (e.g., a list or array) containing the identified object IDs. In order to accomplish this task through the firewall, the activation module 124 preferably puts the vector into a string, referred to as “object data,” and then preferably creates an HTTP message to communicate the object data to the routing network 110. A schematic example is as follows: the HTTP request, it extracts the object data and updates the registry 125 to indicate that the client 114 has registered for the identified objects.
If the web browser 120 loads 616 a new page, or otherwise terminates display of the objects on the initial page, the activation module 124 associated with the initial web page preferably terminates 618 the client's connection with the routing network 110. Those of skill in the art will recognize that this termination 618 can occur asynchronously with the other steps illustrated in
If the connection is not terminated, the activation module 124 preferably waits until it receives 619 a message from the routing network 110 specifying an object ID and an update to a property of the identified object. In one embodiment, this message is received as HTTP data. Upon receipt of the message, the activation module 124 preferably extracts 620 the object ID and update from the HTTP data. Then, the activation module 124 updates 622 the property of the identified object, or causes the object to be updated, as specified by the message.
The sequence of receiving messages 619, extracting data 620, and updating objects 622 is preferably repeated until a new page is loaded 616 or the connection with the routing network 110 is otherwise terminated. Although not shown in
Internally, the routing network 110 is preferably divided into one or more clusters 714. In
Each cluster 714, of which cluster 714A is representative, preferably contains an input-side cluster load balancer 720A and a client-side cluster load balancer 722A. The cluster load balancers 720A, 722A function similarly to the corresponding global load balancers 716, 718 in that the input-side cluster load balancer 720A balances and routes incoming messages among one or more gateways 724A and the client-side cluster load balancer 722A balances and routes incoming connection requests among one or more nodes 726A and application servers 728A.
In one embodiment, the functionality of the two client-side cluster load balancers 720A, 722A is provided by one component. This single-component load balancer initially determines whether an incoming request is from an input source 710 seeking to send a message to a gateway 724A, a client 712 seeking a connection to a node 726A, or a client seeking a connection to an application server 728A. Then, the load balancer routes the messages/connection requests among the gateways 724A, nodes 726A, and application servers 728A within the cluster 714. In one embodiment, the single-component load balancer provides layer seven load balancing (i.e., load balancing at the application layer). Preferably, the load balancing for the nodes 726A and application servers 728A are performed by the same component since, for security reasons, most client web browsers only permit an application (e.g., the activation module 124) to transparently connect to the location from which the application was downloaded.
Alternative embodiments of the routing network 110 may combine the global 716, 718 and cluster 720A, 722A load balancers and/or incorporate the functionality of the load balancers into different components within or outside of the clusters 714. In addition, alternative embodiments may omit one or more of these load balancers. For example, having different clusters 714 serve different customers might obviate the need for the global load balancers 716, 718.
The gateways 724A in the cluster 714 receive the messages from the input sources 710 and direct the messages to the appropriate node or nodes 726A. In one embodiment, each gateway 724A maintains a persistent TCP connection to every node 726 in every cluster 714 and directs every message to every node. Therefore, although a gateway 724A is located inside a cluster 714A and receives connections via the cluster's input-side load balancer 720A, the gateway's scope spans the entire routing network 110. This broad scope allows messages from any input source to reach any client 712.
In an alternative embodiment of the routing network 110, each gateway 724 maintains a persistent TCP connection to all nodes 426 in the same cluster 714 and at least one connection to at least one gateway in each of the other clusters. This embodiment reduces the number of simultaneous TCP connections maintained by each gateway 724. In another alternative embodiment, each cluster 714 also includes a gatekeeper (not shown in
Since a gateway 724 does not control the rate at which it receives messages from input sources 710, it is possible for the gateway to receive messages faster than it can process them (i.e., send the messages to the nodes). Therefore, each gateway 724 preferably maintains a queue 730 of messages that have been received but not yet processed in order to avoid losing messages. In one embodiment, the gateway 724 drops messages if the queue 730 becomes too long. In another embodiment, the gateway 724 utilizes priorities assigned to certain messages or input sources to determine which messages to drop.
The nodes 726 preferably transmit messages received from the gateways 724 to the clients 712 that have registered in the object IDs identified by the messages. If no clients 712 have registered the object ID specified by a message, the node preferably ignores the message. A node 726 preferably maintains an instance of the registry 125 as a hash table 732 containing the object IDs registered by clients 712 connected to the node. In one embodiment, the hash table 732 associates each object ID with a linked list containing one entry for each client 712 that has registered for that object ID. Each entry, in the linked list preferably contains a pointer to a socket representing the connection to the corresponding client 712. As is known in the art, the pointer to the socket, typically called a “file descriptor,” represents an address to which the node can write in order to send the message to the corresponding client. Preferably, the node 726 adds to the hash table 732 and/or linked list every time a client 712 registers an interest in an object and deletes the corresponding entry from the hash table and/or linked list when the client disconnects from the node or otherwise indicates that it is no longer interested in a particular object.
Alternative embodiments utilize other data structures in addition to, or instead of, the hash table 732 and linked list, and/or may utilize different data within the data structures. For example, one embodiment of the routing network 110 has a hierarchy of nodes within each cluster 714. Different nodes in the hierarchy may handle messages received from certain input sources 210, or process messages sent to different clients 712. In this embodiment, the linked lists may point to nodes lower in the hierarchy, instead of to sockets leading to the clients 712. Another embodiment lacks the node hierarchy, yet assigns certain nodes to certain input sources 210 or clients 712.
The application server 728 within each node 714 preferably serves the activation module 124 to the clients 712 in response to client requests. In addition, the application server 728 serves any other modules that may be required or desired to support the environment 100. In an alternative embodiment of the routing network, a single application server 728 fulfills all of the client requests. This application server 728 may be within a certain cluster 714 or independent of the clusters. However, this single-application-server embodiment is less desirable because it lacks redundancy.
In one embodiment, at least one of the nodes 726 is in communication with the OSS 109 in order to provide the update messages to the OSS. In another embodiment, OSS functionality is provided by the node 726 itself.
Preferably, the routing network 110 utilizes conventional single-processor computer systems executing the Linux operating system (OS). Preferably, each component of the routing network 110 is implemented by a separate, dedicated computer system in order to enable the separate optimization of the components. The input/output (I/O) functionality of the OS is preferably enhanced through the use of a non-blocking OS package such as NBIO available from the University of California, Berkeley, Calif. Based on the assumption that connections with the nodes 728 are long-lived, the OS is preferably configured to not allocate resources toward monitoring idle connections. Instead, the well-known/dev/poll patch is preferably applied to the OS in order to provide advanced socket polling capabilities.
Moreover, the TCP/IP stack in the OS is preferably optimized in order to quickly output messages. In one embodiment, the retransmit timer in the stack is reduced from 200 ms to 50 ms. This timer determines how long the stack waits for an acknowledgement (ack) that a sent packet was received. Due to the way the Linux kernel implements the retransmit timer, the kernel will not send pending outbound packets (even if the ack has been received) until the initial retransmit timer has expired. Reducing the retransmit value minimizes the effect of this delay. If an ack is not received before the retransmit timer expires, an embodiment increases the retransmit value for the affected TCP connection and the unacknowledged packet is retransmitted. In addition, the TCP/IP stack preferably utilizes Nagle's algorithm functionality to concatenate a number of small messages into a larger message, thereby reducing the number of packets sent by the routing network 110. handier18.
The above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the disclosure. The scope of the disclosure is to be limited only by the following claims. From the above discussion, many variations will be apparent to one skilled in the relevant art that would yet be encompassed by the spirit and scope of the disclosure. | https://patents.google.com/patent/US9613076B2/en | CC-MAIN-2018-51 | en | refinedweb |
This chapter discusses important programming, configurational, and runtime considerations, as well as special considerations for particular execution environments. The following topics are covered:
This section discusses issues you should consider when programming JSP pages that will run in the OracleJ.
To use an Enterprise JavaBean (EJB) in a JSP page, choose either of the following approaches:
For general information, this section provides two examples of calling an EJB from a JSP page--one where the JSP page runs in a middle-tier environment and one where it runs in the Oracle9i Servlet Engine. These two examples point out some significant advantages in using OSE.
These are followed by an example using the more modular approach of calling an EJB from a JavaBean wrapper.
For general information about the Oracle EJB implementation, see the Oracle9i Enterprise JavaBeans Developer's Guide and Reference.
The following JSP page calls an EJB from a middle-tier environment such as the Oracle9i Oracle9i to execute in the OSE environment, the EJB lookup and invocation is much simpler and highly optimized. In this case, the bean lookup is done locally within the Oracle>
The following example provides a JSP page that calls a JavaBean wrapper, which in turn calls an EJB.
The JSP page uses an instance,
employeeBean, of the
EmployeeEJBWrapper JavaBean class. It calls the
setServiceURL() method on the bean to set the database URL, according to the URL entered through the HTTP request object. It calls the
doCallEJB() method on the bean to call the EJB.
The JavaBean implements the
HttpSessionBindingListener interface. (See "Standard Session Resource Management--HttpSessionBindingListener" for information about this interface.) When the session expires, the
valueUnbound() method is called to destroy the EJB instance.
JNDI setup, in the bean, is accomplished as in the preceding examples.
Following is the JSP page:
<HTML> <%@ page <HEAD> <TITLE> The CallEJB JSP </TITLE> </HEAD> <BODY BGCOLOR="white"> <BR> <% String empNum = request.getParameter("empNum"); String surl = request.getParameter("surl"); String inJServer = System.getProperty("oracle.jserver.version"); // save the parameters in the bean instance if (surl != null) { employeeBean.setServiceURL(surl); } if (empNum != null) { employeeBean.setEmpNumber(empNum); %> <h2><BLOCKQUOTE><BIG><PRE> Employee Salary <%= employeeBean.doCallEJB(Integer.parseInt(empNum), inJServer) %> </PRE></BIG></BLOCKQUOTE></h2> <HR> <% } // show the defaults or the values last entered String val1 = ((empNum == null) ? "7654" : employeeBean.getEmpNumber()); String val2 = ((surl == null) ? "sess_iiop://localhost:2481:ORCL" : employeeBean.getServiceURL()); %> <P><B>Enter the following data: <FORM METHOD=get> Employee Number: <INPUT TYPE=text </FORM> </BODY> </HTML>
And here is the JavaBean code:
package beans; import employee.Employee; import employee.EmployeeHome; import employee.EmpRecord; import oracle.aurora.jndi.sess_iiop.ServiceCtx; import javax.naming.Context; import javax.naming.InitialContext; import javax.servlet.http.HttpSessionBindingListener; import javax.servlet.http.HttpSessionBindingEvent; import java.util.Hashtable; public class EmployeeEJBWrapper implements HttpSessionBindingListener { public EmployeeEJBWrapper() {} // no arg bean constructor private Employee employeeEJB = null; private String empNumber = null; private String serviceURL = null; public String doCallEJB(int empno, String inJServer) { try { if (employeeEJB == null) { Context ic = null; EmployeeHome home = null; if (inJServer == null) { // not running in JServer, usual client setup Hashtable env = new Hashtable(); env.put(Context.URL_PKG_PREFIXES, "oracle.aurora.jndi"); env.put(Context.SECURITY_PRINCIPAL, "scott"); env.put(Context.SECURITY_CREDENTIALS, "tiger"); env.put(Context.SECURITY_AUTHENTICATION, ServiceCtx.NON_SSL_LOGIN); ic = new InitialContext (env); home = (EmployeeHome)ic.lookup (serviceURL + "/test/employeeBean"); } else { // in JServer, use simplified and optimized lookup ic = new InitialContext(); home = (EmployeeHome)ic.lookup ("/test/employeeBean"); } employeeEJB = home.create(); } EmpRecord empRec = empRec = employeeEJB.query (empno); return empRec.ename + " $" + empRec.sal; } catch (Exception e) { return "Error occurred: " + e;} } public void setServiceURL (String serviceURL) { this.serviceURL = serviceURL; } public String getServiceURL () { return serviceURL; } public void setEmpNumber(String empNo) { empNumber = empNo; } public String getEmpNumber() { return empNumber; } public void valueBound(HttpSessionBindingEvent event) { // nothing to do here, EJB will be created when query is submitted } public synchronized void valueUnbound(HttpSessionBindingEvent event) { if (employeeEJB != null) { try { employeeEJB.remove(); // destroy the bean instance } catch (Exception ignore) {} employeeEJB = null; } } }
You can use the following performance enhancement features, supported through Oracle JDBC extensions, in JSP applications executed by OracleJSP:
Most of these performance features are supported by the
ConnBean and
ConnCacheBean data-access JavaBeans (but not by
DBBean). "Oracle Data-Access JavaBeans" describes these beans.J".J"..
OracleJSP. See "ConnBean for a Database Connection" and "ConnCacheBean for Connection Caching" for information about these JavaBeans. or middle-tier database cache while a result set is being populated during a query, reducing the number of round trips to the server.
OracleJSP. See "ConnBean for a Database Connection" and "ConnCacheBean for Connection Caching" for information about these JavaBeans.).
Here is an example of
jsp:includeJ9i, the
-extres and
-hotload options of the
ojspc pre-translation tool, and the
-hotload option of the
publishjsp session shell command, also offer.
OracleJSP wrap-around.
For the following reasons, JSP pages are a poor choice for generating binary data. Generally you should use servlets instead.
JspWriterobject.
.giffile, for example) covers important effects of how you set key
page directive parameters and OracleJ OracleJSP disabling the OracleJSP
developer_mode flag (
developer_mode=false).
The default setting is
true. For information about how to set this flag in the Apache/JServ, JSWDK, and Tomcat environments, see "OracleJSP Configuration Parameter Settings".
If a JSP page does not need an HTTP session (essentially, does not need to store or retrieve. For background information, see "Servlet Sessions".)
OracleJSP uses its own classpath, distinct from the Web server classpath, and by default uses its own class loader to load classes from this classpath. This has significant advantages and disadvantages.
The OracleJSP classpath combines the following elements:
classpathparameter
If there are classes you want loaded by the OracleJSP class loader instead of the system class loader, use the OracleJSP
classpath configuration parameter, or place the classes in the OracleJSP default classpath. See "Advantages and Disadvantages of the OracleJSP Class Loader" for related discussion.
Oracle JSP defines standard locations on the Web server for locating
.class files and
.jar files for classes (such as JavaBeans) that it requires. OracleJSP will find files in these locations without any Web server classpath configuration.
These locations are as follows and are relative to the application root:
/WEB-INF/classes /WEB-INF/lib /_pages. OracleJSP OracleJSP
classpath configuration parameter to add to the OracleJSP classpath.
For more information about this parameter, see "OracleJSP Configuration Parameters (Non-OSE)".
For information about how to set this parameter in the Apache/JServ, JSWDK, and Tomcat environments, see "OracleJSP Configuration Parameter Settings".
Using the OracleJSP class loader results in the following advantages and disadvantages:
When a class is loaded by the OracleJSP class loader , its definition exists in the OracleJSP class loader only. Classes loaded by the system class loader or any other class loader, including any servlets, would have only limited access. The classes loaded by another class loader could not cast the OracleJSP-loaded class or call methods on it. This may be desirable or undesirable, depending on your situation.
By default, the OracleJSP class loader will automatically reload a class in the OracleJJSP classpath. By default, the
classpath parameter is empty.
This section describes conditions under which OracleJSP retranslates pages, reloads pages, and reloads classes during runtime. This discussion does not apply to JSP pages running in the Oracle9i".
The Oracle9i Servlet Engine (OSE) is integrated with the Oracle9i database and middle-tier database cache. To run in OSE, a JSP page must be deployed (loaded and published) into Oracle9i. The details of deploying JSP pages into Oracle9i are discussed in Chapter 6, "JSP Translation and Deployment". This section discusses special programming considerations for the OSE environment and provides an overview of key OSE characteristics.
A JSP application can run in OSE by using the Oracle HTTP Server, powered by Apache, as a front-end Web server (generally recommended), or by using OSE as the Web server directly. See "Oracle Web Application Data-Access Strategies". When installing Oracle9i, Oracle HTTP Server is set as the default Web server. Refer to your installation instructions if you want to change this setting.
It is assumed that JSP pages running in the Oracle9i Servlet Engine are intended for data access, so some background is provided on database connections through Java.
JSP code is generally completely portable between OSE and other environments where OracleJSP is used. The exception is that connecting through the JDBC server-side internal driver is different (for example, does not require a connect string), as mentioned in "Database Connections Through Java".
Aside from connecting through the server-side internal driver or using any other features specific to the Oracle JVM, JSP pages written for OSE are portable to other environments running OracleJSP. The original code has to be modified and re-translated only if Oracle9i-specific features were used.
The following topics are covered here:
Each Oracle session through Java invokes its own dedicated Java virtual machine. This one-to-one correspondence between sessions and JVMs is important to keep in mind.
Any Java program running inside a JVM in the target Oracle9i database or middle-tier database cache typically uses the JDBC server-side internal driver to access the local SQL engine. This driver is intrinsically tied to Oracle9i and the Oracle JVM. The driver runs as part of the same process as the database. It also runs within a default Oracle session--the same session in which the JVM was invoked.
The server-side internal driver is optimized to run within the database or database cache and provide direct access to SQL data and PL/SQL subprograms. The entire JVM operates in the same address space as the database or database cache and the SQL engine. Access to the SQL engine is a function call--there is no network. This enhances the performance of your JDBC programs and is much faster than executing a remote Oracle Net call to access the SQL engine.
The information here is applicable for connections to either the middle-tier database cache or the back-end database. (Both are referred to as simply "the database" for this discussion.)
Because the JDBC server-side internal driver runs within a default Oracle session, you are already "connected" to the database implicitly. There are two JDBC methods you can use to access the default connection:
defaultConnection()method of the
OracleDriverclass. (This returns the same connection object each time it is called.)
DriverManager.getConnection()method, with either
jdbc:oracle:kprbor
jdbc:default:connectionas the URL string. (This returns a different connection object each time it is called.)
Using the
defaultConnection() method is generally recommended.
It is also possible to use the server-side Thin driver for an internal connection (a connection to the database in which your Java code is running), but this is not typical.
For more information about server-side connections through Oracle JDBC, see the Oracle9i JDBC Developer's Guide and Reference.
The
oracle.jdbc.driver.OracleDriver class
defaultConnection() method is an Oracle extension you can use to make an internal database connection. This method always returns the same connection object. Even if you invoke this method multiple times, assigning the resulting connection object to different variable names, a single connection object is reused.
The
defaultConnection() method does not take a connect string. For example:
import java.sql.*; import oracle.jdbc.driver.*; and, therefore, a new transaction.
Instead of using the
defaultConnection() method to make an internal database connection, you can use the static
DriverManager.getConnection() method with either of the following connect strings:
Connection conn = DriverManager.getConnection("jdbc:oracle:kprb:");
or:
Connection conn =, known as "type maps". A type map, for mapping Oracle SQL object types to Java classes, is associated with a specific
Connection object and with any state that is part of the object. If you want to use multiple type maps as part of your program, then you can call
getConnection() to create a new
Connection object for each type map. For general information about type maps, see the Oracle9i JDBC Developer's Guide and Reference.
The Oracle JDBC server-side Thin driver is generally intended for connecting to one database from within another database. It is possible, however, to use the server-side Thin driver for an internal connection. Specify a connect string as you would for any usage of the Oracle JDBC Thin driver.
This feature offers the possible advantage of code portability between the Oracle9i Servlet Engine and other servlet environments; however, the server-side internal driver offers more efficient performance.
The JDBC auto-commit feature is disabled in the server-side internal driver. You must commit or roll back changes manually.
Connection pooling and caching is not applicable when using the server-side internal driver, because it uses a single implicit database connection. Attempts to use these features through the internal driver may actually degrade performance.
The Oracle9i Servlet Engine uses a JNDI mechanism to look up "published" JSP pages and servlets, although this mechanism is generally invisible to the JSP developer or user. Publishing a JSP page, which you accomplish during deployment to OSE, involves either running the Oracle session-shell
publishjsp command (for deployment with server-side translation) or running the session-shell
publishservlet command (for deployment with client-side translation).
The
publishservlet command requires you to specify a virtual path name and a servlet name for the page implementation class. The virtual path name is then used to invoke the page through a URL, or to include or forward to the page from any other page running in OSE.
The
publishjsp command can either take a virtual path name and servlet name on the command line, or will infer them from the JSP source file name and directory path that you specify.
Both the servlet name and the virtual path name are entered into the Oracle9i JNDI namespace, but the JSP developer or user need only be aware of the virtual path name.
For more information about publishing a JSP page for OSE, see "Translating and Publishing JSP Pages in Oracle9i (Session Shell publishjsp)", for deployment with server-side translation, or "Publishing Translated JSP Pages in Oracle9i (Session Shell publishservlet)", for deployment with client-side translation.
For general information about how the Oracle9i Servlet Engine uses JNDI, see the Oracle9i Servlet Engine Developer's Guide.
Some OracleJSP configuration parameters take effect during translation; others take effect during runtime. When you deploy JSP pages to Oracle9i to run in the Oracle9i Servlet Engine, you can make appropriate translation-time settings through command-line options of the OracleJSP pre-translation tool.
At runtime, however, OSE does not support execution-time configuration parameters. The most significant runtime parameter is
translate_params, which relates to globalization support. For a discussion of equivalent code, see "Code Equivalent to the translate_params Configuration Parameter".
There are special considerations in running OracleJSP in Apache/JServ-based platforms, including Oracle9i9i Application Server, discusses the following Apache-specific considerations:
As of Oracle9i Application Server release 1.0.x, this product uses Apache/JServ as its servlet environment. As in any Apache/JServ or other servlet 2.0 environment, there are special considerations relating to servlet and JSP usage. These are detailed in the sections that follow.
For a brief overview of the Oracle9i for servlet 2.0 environments does not, however, allow dynamic forwards or includes to servlets. (Servlet execution is controlled by the JServ or other servlet container, not the OracleJSP container.)
If you want to include or forward to a servlet in Apache/JServ, however,).
Be aware that setting
alias_translation=true also results in the alias directory becoming the application root. Therefore, in a dynamic
include or
forward command where the target file name starts with "/", the expected target file location will be relative to the alias directory.
Consider the following example, which results in all JSP and HTML files under
/private/foo being effectively under the application
/mytest:
Alias /mytest/ "/private/foo/"
And assume there is a JSP page located as follows:
/private/foo/xxx.jsp
The following dynamic
include command will work, because
xxx.jsp is directly below the aliased directory,
/private/foo, which is effectively the application root:
<jsp:include
JSP pages in other applications or in the general doc root cannot forward to or include JSP pages or HTML files under the
/mytest application. It is only possible to forward to or include pages or HTML files within the same application (per the servlet 2.2 specification). | https://docs.oracle.com/cd/A91202_01/901_doc/java.901/a90208/keydev.htm | CC-MAIN-2018-51 | en | refinedweb |
SQLAlchemy 1.3 Documentation
SQLAlchemy 1.3 Documentation
beta release (such as for test suites)(). (But note that if the return value is
used as a context manager, i.e. in a with-statement, then this rollback/commit
is issued by the context manager upon exiting the context, and so should not be
added explicitly.)
Session.begin() method also returns a transactional token which is
compatible with the non-transactional, delimiting construct that
allows nesting of calls to
begin() and
commit().
Its(). = self.connection.begin() # bind an individual Session to the connection self.session = Session(bind=self.connection) def test_something(self): # use the session in tests. self.session.add(Foo()) self.session.commit() def tearDown(self): self.session.close() # rollback - everything that happened with the # Session above (including calls to commit()) # is rolled back. self.trans.roll.
Supporting Tests with Rollbacks
The above recipe works well for any kind of database enabled test, except
for a test that needs to actually invoke
Session.rollback() within
the scope of the test itself. The above recipe can be expanded, such
that the
Session always runs all operations within the scope
of a SAVEPOINT, which is established at the start of each transaction,
so that tests can also rollback the “transaction” as well while still
remaining in the scope of a larger “transaction” that’s never committed,
using two extra events:
from sqlalchemy import event class SomeTest(TestCase): def setUp(self): # connect to the database self.connection = engine.connect() # begin a non-ORM transaction self.trans = connection.begin() # bind an individual Session to the connection self.session = Session(bind=self.connection) # start the session in a SAVEPOINT... self.session.begin_nested() # then each time that SAVEPOINT ends, reopen it @event.listens_for(self.session, "after_transaction_end") def restart_savepoint(session, transaction): if transaction.nested and not transaction._parent.nested: # ensure that state is expired the way # session.commit() at the top level normally does # (optional step) session.expire_all() session.begin_nested() # ... the tearDown() method stays the same | https://docs.sqlalchemy.org/en/latest/orm/session_transaction.html | CC-MAIN-2018-51 | en | refinedweb |
This guy seems to be having problems with HD service on Time Warner digital cable.
But from reading his post, and having my own experiences with Time Warner and HD, I think his problems fall under the category of “user error.”
When I wanted an HD box from Time Warner, I took my digital cable box to their local walk-in service/store location and asked for the HD box. They said, “do you have an HDTV?” Of course I said “yes.” They then took my old box and gave me a new one.
When I heard that the 8000HD (the DVR HD box) was becoming available, I called up TW and asked about it. They said it would be here in a few weeks (this was back in May or so). I actually heard about a week later at work that one of my co-workers had just picked up their HD DVR box for their living room. So naturally I went home on my lunch break, grabbed my box, and proceeded to the TW store to get it replaced. Keep in mind, the DirecTV Tivo box that everyone raves about costs $1000 and you have to pay extra for both the DVR subscription and an HD subscription. My box was free, as long as I pay the $5/month DVR subscription fee. There is no charge for HD content on Time Warner Cable.
I had absolutely no problems with my box. Now, it’s not perfect. It doesn’t always pick the right setting in regards to adapting 4:3 programs to my widescreen monitor. It also occasionally picks the wrong setting for 480p/1080i/pass-through mode. But most of the time it works fine – and changing that setting requires exactly two buttons on the remote (the “settings” button, which defaults to that option, and “right” to change the setting to where I want it).
The guy that I linked to above had the following problems:
<![if !supportLists]>1) <![endif]>No DVI output. This one I can’t really address since I haven’t used it myself. From what I’ve read, DVI is not enabled on the 8000HD boxes, for whatever reason. Some say it will be enabled in the future.
<![if !supportLists]>2) <![endif]>He complains “Time Warner has disabled the DVI output, the RF output and the S-Video output on the box.” That’s simply not the case. I’ve used the S-Video output on my box without any trouble. Of course, it helps if you read the manual or look at the Quick Setup card they give you. It very clearly states that you have to use the “Setup wizard” to correctly configure the outputs that you want enabled.
<![if !supportLists]>3) <![endif]>He says “The only way to get HD cable is with an RGB component video pigtail cable.” Anyone who knows anything about modern A/V equipment knows that virtually every HD monitor has Y/Pb/Pr component inputs. That is NOT RGB. I’m willing to bet his does as well. Y/Pb/Pr is what every progressive scan DVD player uses, the Xbox uses, and just in general IS the HDTV connectivity standard. Why he uses some obscure “RCA/RGB to D-Sub 15” cable is beyond me. And he wonders why his picture doesn’t look right.
<![if !supportLists]>4) <![endif]>He complains about his inability to control the volume output when using the Digital Audio connection. Of course, if he’d read the manual (or looked in the Settings menu) he’d see that there’s an option for “Fixed” or “Variable” digital audio output. Guess which one his is set to. Furthermore, who the heck wants to control their digital audio volume at the source? That’s what your receiver is for. That’s why “Fixed” is the default option, because that’s what everyone wants anyway.
<![if !supportLists]>5) <![endif]>He says “What's all of that digital noise, why does the picture stop and start? What are all of those artifacts?” Perhaps it has something to do with the horrendous cabling he opted to use? Maybe if he’d used the component video cables that TWC PROVIDES he wouldn’t have such a bad picture. As for the picture starting and stopping… that’s something I’ve never seen.
<![if !supportLists]>6) <![endif]>“Why does the box use gray letterboxing for 4:3?” Perhaps because he set the “letterboxing” option in the Settings menu to “grey?”
<![if !supportLists]>7) <![endif]>“If I thought that switching a digital cable channel was painful, just add the aspect radio adjustment for an extra two seconds to make the channel switch weigh in at an impressive 3.5 seconds per.” If he knew anything about digital cable, he’d know that a standard digital or HD digital box has no delay. The delay comes because of the DVR functionality, as it buffers its 1-hour recording cache. Every DVR setup I’ve seen has this slight delay. You tend to get used to it. Though it is something I’d hope they would improve in the future… there are limitations to how fast the hard drive can adapt.
.”
This is completely contrary to my experience. In my area (NY capital district), there are about 15 HD channels. Perhaps he doesn’t know about the 1800 range of channels (all HD). In my area they include HBO, Showtime, three for the four major local stations (the fourth has a “Coming soon” message – though I haven’t looked lately to see if it’s changed), and several others. I also thoroughly enjoy HD content in my Xbox games and on HD shows that I download and stream to the Xbox Media Center app on my modded Xbox. In addition to that, Progressive Scan for DVDs certainly looks very, very good.
Clearly, improvements need to be made to smooth the transition for first-time users. But this guy knows full well he’s venturing into newly charted territory… and what’s more, the convergence of two very new technologies (DVR and HD) and some hiccups are to be expected. The thing is, most of his problems could be solved by reading the manual and following the instructions provided with the hardware. And I think it’s unfortunate when he tries to give TWC and Scientific Atlanta a bad rap when, from what I’ve seen, they’ve done the best job at making these technologies accessible to the public. $1000 for a box is a pretty steep price tag for DirecTV. And Comcast charges for HD content. Their Motorola cable boxes are garbage with a laughable interface.
Voom is an interesting concept that I’ve not seen personally. But like DirecTV, it seems like too steep of a price and commitment for little return (*most* of the HD content they offer is also available on TWC).
posted @ Monday, October 11, 2004 3:39 PM | http://geekswithblogs.net/bpaddock/archive/2004/10/11/12501.aspx | crawl-002 | en | refinedweb |
Farhan Khan
Tuesday, December 18, 2007
#
MS has recently released a Business User training portal which can be installed on SPS and offers course-like environment where every user can track the completion of chapters/sections that focus upon various portal tasks. Im glad that MS has finally catered to something that should have been catered to long ago.
I have had the personal opportunity to install, play & present it at a client engagement and I must confess that the simple idea of having your own course is fabulous. The IT has no worries of scheduling, ensuring attendance, tracking progress of the portal training, thereby saving much of already hard-to-get time of business users and also making IT budget for the year :)
Any Business User (with access to portal) can simply logon to the training site which may be a site within the enterprise portal or even another server (should IT be concerned about the space usage and/or the intent of training being different from live portal) and do training at her own time. The course offers a variety of materials: interactive, video, presentation. Below you will find a sample 'table of contents' from a live training site.
Monday, December 17, 2007
#
My opinion so far about every Google initiative is that they do it better than most and almost always accompanied with a sizeable business strategy to backup the product.
Latest in their offerings is their version of wikipedia: Knol is different because it credits and pays the authors and by the same token makes them accountable too thereby offering at least a bit more realiability than free-form authoring ~Smile~. I am very interested in seeing how the accountability comes into play.
Accuracy of information in rare but conspicuous cases proved to be a pain point with Wikipedia however the 'model-shift' towards accountability in Knol and its acceptability would be interesting and only remains to be seen once it comes live. Such a model could have its own pros and cons because from the looks of it the Google plans to balance the ownership factor with the ratings applied and this implies a lot of user feedback, again something that can only be successful with time and adequate user participation.
For more information about Knol, please click here.
Wednesday, December 12, 2007
#
After iPhone, few other names have been making frequent rounds of the internet recently. Since I am an early adopter of iPhone and majorly interested in gPhone and any other variants I thought I might as well jump in and clarify some terms and/or miconceptions at play here.
iPhone as you may already be aware is an actual phone running a stripped down version of the famous Mac OS X. The iPhone has gone through many firmware upgrade ever since its introduction a while ago. In North America, Apple has teamed up with AT&T and 'locked' the phone down for AT&T use only but that has not prevented the enthusiastic technologists to find ways to unlock the iPhone. Such technologists have been playing a catchup game, because Apple has been issuing upgrades at regular intervals for enhancements and to foil unlocking efforts. Currently iPhone is running OS v1.1.2 which by the way has already been successfully unlocked to be used without the AT&T agreement anywhere in the world.
gPhone aka Google Phone is a slightly misleading term. In Nov 2007 Google announced that they are looking to build an mobile phone platform code named Android (not a phone per se). The platform is going to be founded upon Linux OS, please refer to the link for an overview of the Android as a platform. Google has once again been true to its legacy and the most appealing aspect of the new platform is the 'free' ability to build and add applications to the platform since the code and API for the platform would be shared under the Apache license.
Lastly Skype is also in the process of launching its own version of the phone the highlight of which is not the gadget but the plans associated with it. There are no immediate plans to bring it to North America. If you are still curious click here.
Tuesday, December 11, 2007
#
If you have deployed or are in the middle of a MOSS deployment, SP1 should be of major interest to you. It addresses many of the product issues that your team may have realized during the implementation/configuration of the platform.
Personally I have experienced two issues which would be resolved by SP1:
For more information, please refer to the MS Sharepoint Blog
Service Packs have been released moments ago and you can now download WSS SP1 here & MOSS SP1 here.
Monday, December 10, 2007
#
Its a runtime to...
What its NOT....
What the future is like for Silver Light remains to be seen; instead of repeating the discussion, I will point to a very interesting discussion on the future proespects of the runtime by Jeremy.
Thursday, December 06, 2007
#
Since I am currently leading an enterprise portal rollout, I wanted to share a few thoughts on whats there in such effort that does not meet the eye.
Political factors aside, strictly on the technical end there are a few creases that need to be ironed out early in the project and some of those are
Every project remains unique however the above approach caters to most portal projects and while technology factors may change, little do they affect the overall course of such efforts.
Wednesday, November 28, 2007
#
First.
Friday, December 08, 2006
# :)
Thursday, February 02, 2006
#
Thursday, August 18, 2005
#
Since),
Win + R = Run Command, Win + Shift + M = Maximize all windows, Win + L (XP) = Lock OS,
Alt + Tab = Shift between Windows, Alt + Shift + Tab = Shift between Windows (Reverse Order), Alt + Spacebar + N = Minimize current window,
Alt + F4 = Close Current Window, Alt + Spacebar + X = Maximize, Alt + Spacebar + R = Restore,
Ctrl+X = Cut, Ctrl+C = Copy, Ctrl+V = Paste, Ctrl+A = Select ALL, Ctrl+P = Print, Ctrl+ Shift + F10 = Shows Context Menu (Mouse Right Click Effect),
Ctrl+Esc = Start Menu, Ctrl + Shift + Esc = Show Task Manager,.
Wednesday, November 30, 2005
#
Career means different things to each of us and so does success, some attribute it to increasing monetary gains while others may ascribe it to personal satisfaction and then again the personal satisfaction may have different meanings to each of us and it can go on and on...
I am not here to argue about perceptions since that kind of analysis ie beyond my expertise, the motivation to write these few lines is to underline the importance of Business/Vertical/Industry Knowledge for success or even for survival, so to speak. Over the past few years, my humble observations have indicated that business acumen of an individual has become a primary factor for his success in any stream. Some 5-10 years ago, things used to be much different whereby the knowledge of technology alone would suffice to procure you a job or success in a job but things have radically changed over the course of time. Now an individual's comprehension of the business or the industry he aspires to serve, is a deciding factor whether he would be a good fit for the organization or not. Organizations already look for people who have the basic technological expertise as well as the business understanding and more than that the ability to foresee how the technology can serve the business based on their understanding of the business.
So far I have pointed out the changing trends, and say if we call it a 'problem' there just has to be a solution :) In my humble opinion, technological expertise will continue to remain important yet the business acumen will take precendence on the front stage and although technology will never be less than vital yet its fate will primarily be driven by the business and therefore a substantial part of any technologist's career should encompass the business and its path as well.
You may find the above statement more applicable to consultancy world, yet as I look at it I even see the products in future to be dependent upon business; may be I am stating the obvious yet the point I am trying to make is that even as pure technologists evolve in their careers they must meet with the challenge of understanding the business better than they already do.
What substantiates my observation above is the off-shore model rapidly taking over North America. I see a lot of technology implementation being pushed out of North America to Asia etc and what remains is the technology analysis. I am not too sure if its a good thing or not yet to survive in this increasingly competitive market we must load ourselves with the business understanding weapons.
The weekend was pretty hectic as I tried to install Longhorn Beta 1 but the effort proved futile on my VPC. The machine kept rebooting after the initial product key/info screens and although once it got as far as two hours of installation but then rebooted only to complain of Boot.ini.
The Vista was a breeze though as it installed on the first try (though I experienced a little friction through Reboots). For some reason mapping the ISO image of the Vista CTP directly to the VPC machine configuration under Virtual Server 2005 had problems. So I had to load the Daemon tools and mount the image on host system and then connect the VPC CD/DVD to the host mounted image of Vista.
I must say that this time around MS folks have done a pretty good job with the Vista installation sequence since minimal user input is required for the the compelte OS installation.
Tuesday, November 08, 2005
#
The example here builds a sample workflow which is event driven. The test harness will emulate a Document arrival notification and send notification to the workflow. Upon receipt of the event the workflow shall come out of its latent state and become active. The workflow will then check if the passed in data is for urgent processing (based on Priority parameter passed) and process it accordingly. The code has been kept very simple with fictitious processing times e.g. making thread sleep longer for normal processing etc.
The emphasis is on how to invoke the workflow, pass parameters and utilize some basic activities within the WF development environment.
First off, the development environment includes the following:
Windows Server 2003 with SP1
Visual Studio Final Release
Windows Workflow Foundation - Visual Studio Extensions [published in Nov’05]
First off, the development environment includes the following:
using System;
using System.Workflow.ComponentModel;
using System.Workflow.Runtime;
using System.Workflow.Runtime.Messaging;
[DataExchangeService]
public interface INotificationService
{
event EventHandler<NotificationEventArgs> NotificationAArrived;
event EventHandler<NotificationEventArgs> NotificationBArrived;
}
[Serializable]
public class NotificationEventArgs : WorkflowMessageEventArgs
private string notificationId;
public NotificationEventArgs(Guid instanceId, string notifId)
: base(instanceId)
{
notificationId = notifId;
}
public string NotificationId
get { return notificationId; }
set { notificationId = value; }
public class NotificationService : INotificationService
public NotificationService()
{ }
public void RaiseNotificationAArrivedEvent(string notifId, Guid instanceId)
if (NotificationAArrived != null)
NotificationAArrived(null, new NotificationEventArgs(instanceId, notifId));
public void RaiseNotificationBArrivedEvent(string notifId, Guid instanceId)
if (NotificationBArrived != null)
NotificationBArrived(null, new NotificationEventArgs(instanceId, notifId));
public event EventHandler<NotificationEventArgs> NotificationAArrived;
public event EventHandler<NotificationEventArgs> NotificationBArrived;
public string Priority
get { return (string) Parameters["Priority"].Value; }
set { Parameters["Priority"].Value = value; }
public string Data
get { return (string) Parameters["Data"].Value; }
set { Parameters["Data"].Value = value; }
public string Status
get { return (string) Parameters["Status"].Value; }
set { Parameters["Status"].Value = value; }
private void code1_ExecuteCode(object sender, EventArgs e)
//this.Status = SampleUtils.DoSomeWork(10);
this.Status += "(Priority Processing)";
static AutoResetEvent waitHandle = new AutoResetEvent(false);
IASequentialSample.NotificationService notifService = null;
WorkflowRuntime runtime = null;
StringBuilder sb = null;
private void button1_Click(object sender, EventArgs e)
StartWorkflowRuntime();
Guid instanceID = Guid.NewGuid();
Assembly asm = Assembly.Load("IASequentialSample");
Type workflowType = asm.GetType("IASequentialSample.Workflow1");
Dictionary<string, object> parameters = new Dictionary<string, object>();
parameters.Add("Priority", textBox1.Text);
parameters.Add("Data", "Some Data");
WorkflowInstance ins = runtime.StartWorkflow(workflowType, parameters);
notifService.RaiseNotificationAArrivedEvent("someId", ins.InstanceId);
waitHandle.WaitOne();
runtime.StopRuntime();
textBox1.Text = sb.ToString();
private void StartWorkflowRuntime()
runtime = new WorkflowRuntime();
sb = new StringBuilder();
// Register event handlers for the WorkflowRuntime object
runtime.WorkflowTerminated += new
EventHandler<WorkflowTerminatedEventArgs>(WorkflowRuntime_WorkflowTerminated);
runtime.WorkflowCompleted += new
EventHandler<WorkflowCompletedEventArgs>(WorkflowRuntime_WorkflowCompleted);
// Add a new instance of the Notification Service to the runtime
notifService = new IASequentialSample.NotificationService();
runtime.AddService(notifService);
// Start the workflow runtime
runtime.StartRuntime();
public void WorkflowRuntime_WorkflowTerminated(object sender, WorkflowTerminatedEventArgs e)
{ sb.Append("Workflow Runtime terminated"); }
public void WorkflowRuntime_WorkflowCompleted(object sender, WorkflowCompletedEventArgs e)
sb.Append("Workflow Runtime Completed; Status Returned = " + e.OutputParameters["Status"]);
waitHandle.Set();
The workflows that are not event driven are even simpler to run by simply starting and stopping the workflow through the WorkflowRuntime.
You may try out other activities or code your own however above account will do the basic plumbing for you to get an event driven workflow running.
If you are interested in a developing a State machine workflow there are already many references/tutorials out on the web.
In particular, I found the following very helpful while understanding the concepts: (Hello world)
Saturday, November 05, 2005
#
Finally a WF that will not give you any 'Package Load' error on VS.NET 2005 Release version launch. I have just downloaded and installed it on my VM.
I will be posting more about my experiments with WF later on, for now you can download here and play with it yourself .
It seems that the first installation was not all that smooth and things had to be reinstalled to get everything working. Although there were not 'Package Load' Failures, this time the development environment would become unstable on the launch of certian workflow console applications. Having said that a complete re-install of WF did the trick for me and I have been successfully able to develop, run and test workflows over the weekend.
Monday, October 31, 2005
#
So Google has already launched Google Base which is said to be an eMarket like eBay (screenshots are already available on the web posted by those fortunate enough to log in for once); apparently Google seems to follow SSO (single sign-on) :-) and therefore your Gmail account should be able to log you in. MS also seems to follow the google foot prints and they have their showcase up @. Start.com application seems to be the most interesting product from the showcase typically boasting web-parts feeding off RSSs. Certainly worth a glance......
Skin design by Mark Wagner, Adapted by David Vidmar | http://geekswithblogs.net/cenvy/Default.aspx | crawl-002 | en | refinedweb |
Wednesday, May 27, 2009
There.
posted @ Wednesday, May 27, 2009 1:12 AM | Feedback (0) |
Filed Under [
ASP.NET
]
Tuesday, May 26, 2009
.NET's SqlDataReader class is based on an active connection to the database. This means that while the SqlDataReader is in use, the SqlConnection that is serving the SqlDataReader is open and cannot be used anywhere else.
That is why, returning an SqlDataReader from a method is not stright forward like returning a DataTable or a DataSet. To read more about SqlDataReader, please see SqlDataReader class.
Though it is not straight forward, it is very simple. Here's a piece of code that would let you return a SqlDataReader from a method:
}
posted @ Tuesday, May 26, 2009 1:58 AM | Feedback (0) |
Filed Under [
ASP.NET
]
Wednesday, April 29, 2009
Found a nice post by Mr.Polite for compressing JPEG images. Here's the link:
Posting the code here for my reference in case the original post gets deleted or changed.
Image myImage = //... load the image somehow
// Save the image with a quality of 50%
SaveJpeg (destImagePath, myImage, 50);
//add this!
using System.Drawing.Imaging;
/// <summary>
/// Saves an image as a jpeg image, with the given quality
/// </summary>
/// <param name="path">Path to which the image would be saved.</param>
// <param name="quality">An integer from 0 to 100, with 100 being the
/// highest quality</param>
public static void SaveJpeg (string path, Image img, int quality)
{
if (quality<0 || quality>100)
throw new ArgumentOutOfRangeException("quality must be between 0 and 100.");
// Encoder parameter for image quality
EncoderParameter qualityParam =
new EncoderParameter (Encoder.Quality, quality);
// Jpeg image codec
ImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
EncoderParameters encoderParams = new EncoderParameters(1);
encoderParams.Param[0] = qualityParam;
img.Save (path, jpegCodec, encoderParams);
}
/// <summary>
/// Returns the image codec with the given mime type
/// </summary>
private static ImageCodecInfo GetEncoderInfo(string mimeType)
{
// Get image codecs for all image formats
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
// Find the correct image codec
for(int i=0; i<codecs.Length; i++)
if(codecs[i].MimeType == mimeType)
return codecs[i];
return null;
}
posted @ Wednesday, April 29, 2009 8:15 AM | Feedback (0) |
Filed Under [
ASP.NET
]
Tuesday, March 17, 2009
posted @ Tuesday, March 17, 2009 1:54 AM | Feedback (0) |
Filed Under [
ASP.NET
]
Monday, February 02, 2009
posted @ Monday, February 02, 2009 4:47 AM | Feedback (3) |
Filed Under [
ASP.NET
]
Wednesday, January 21, 2009
Aashish Gupta has posted a nice list of shorcuts in Visual Studio.
Here's the link:
posted @ Wednesday, January 21, 2009 4:25 AM | Feedback (0) |
Friday, January 09, 2009
posted @ Friday, January 09, 2009 1:20 AM | Feedback (2) |
Monday, January 05, 2009
There might be other reasons for this error but this is what I found out:
You might get the error when you have a databound AJAX reorderlist and you are trying to persist the reordering using database.
The SELECT and UPDATE methods should have the same number of fields, even if they are not used in UPDATE, the signature of both the methods should be matching else you will get this error.
Here is very good article on how to use AJAX Reorderlist with ObjectDataSource by Justin Saraceno.
posted @ Monday, January 05, 2009 1:14 AM | Feedback (3) |
Friday, January 02, 2009
Scenario - My stored procedure just returns some integer values depending on different conditions. There are no OUT or any other parameters involved for returning values from the stored procedure.
e.g.
IF (EXISTS( SELECT * FROM TableName WHERE UserId = @UserId AND RoleId = @RoleId))
RETURN(1)
ELSE
RETURN(0)
If you notice, there are no output parameters involved here. The return value can be accessed from code (C# for example), like this:
int returnValue = (int)returnValueParam.Value;
posted @ Friday, January 02, 2009 8:08 AM | Feedback (0) |
Thursday, December 25, 2008
Joe Stagner posted this very useful link for a free C# and VB coding standards reference documents by Clint Edmonson. I really appreciate Clint Edmonson's effort.
Free C# and VB Coding Standards Reference Documents
posted @ Thursday, December 25, 2008 8:48 AM | Feedback (0) | | http://geekswithblogs.net/bullpit/Default.aspx | crawl-002 | en | refinedweb |
Building great s0ftware, 1 line at a time.
Friday, June 26, 2009
#
Yes, this is possibly the simplest app ever written and was cooked up as a lunch bet between myself (@sundriedcoder) and David Justice (@davidjustice) while waiting on our TFS server to be rebuilt. Goal, set a property one million times. Ah ha, here’s the catch! Do it once with Reflection, once using C# 4.0 dynamics and once using a plain old property setter (POPS – I just made this acronym up). The results just might amaze and frighten you. See below or just copy and paste into your VS 2010 console app and hit F5.
What will this code do?
1: class Program
2: {
3: static void Main(string[] args)
4: {
5: var nTimes = 1000000;
6: var value = "Hello World";
7: var myTestType = new MyTestType();
8: DateTime start, end;
9: var property = typeof(MyTestType).GetProperty("MyDynamicProperty");
10:
11: start = DateTime.Now;
12: for (var i = 0; i < nTimes; i++)
13: {
14: //var property = typeof(MyTestType).GetProperty("MyDynamicProperty");
15: property.SetValue(myTestType, value, null);
16: }
17: end = DateTime.Now;
18: Console.WriteLine(end.Subtract(start).ToString());
19:
20: dynamic myTestType2 = new MyTestType();
21: start = DateTime.Now;
22: for (int i = 0; i < nTimes; i++)
23: {
24: myTestType2.MyDynamicProperty = value;
25: }
26: end = DateTime.Now;
27: Console.WriteLine(end.Subtract(start).ToString());
28:
29: var myTestType3 = new MyTestType();
30: start = DateTime.Now;
31: for (int i = 0; i < nTimes; i++)
32: {
33: myTestType3.MyDynamicProperty = value;
34: }
35: end = DateTime.Now;
36: Console.WriteLine(end.Subtract(start).ToString());
37:
38: Console.ReadLine();
39: }
40:
41: public class MyTestType
42: {
43: public string MyDynamicProperty { get; set; }
44: }
45: }
RESULTS
Here are the results as run on my machine. Your results may vary but probably not by much.
FINAL VERDICT
My take away from this is that performance is probably not a good reason to avoid using dynamics if it saves you from having to write a lot of code. Of course, dynamics are a tool that should be applied wisely, aka: Use at your own risk. I hope you enjoy this post, I will be enjoying my free lunch. Thanks Dave ;)
Skin design by Mark Wagner, Adapted by David Vidmar | http://geekswithblogs.net/SunnyCoder/Default.aspx | crawl-002 | en | refinedweb |
Article Source:
I've been asked the same question a few times recently by a couple of BizTalk projects about how to map their reference data. When this question comes up we often get involved in a discussion about the pros and cons of caching the reference data and increasing memory usage versus hitting the database every time.
As a rule I tend to use the BizTalk Cross Referencing features for this data mapping unless there is a specific requirement which requires some custom approach. I've blogged about this kind of thing a few times before but I thought its worth a post with some thoughts on the different approaches I've seen used when people have wanted to use caching.
I mentioned in a previous post that the Value cross referencing features already implement a simple caching mechanism. In my opinion though the value cross referencing is aimed more at mapping data type values between types of systems rather than business reference data which would be held in instances of systems which is what I feel the ID cross referencing is aimed more at.
Anyway when it comes to this design decision the things people are usually trying to balance are as follows:
There are a number of possible ways to solve this problem and each have their own considerations which are discussed in the rest of this article.
This is probably the most common approach I've seen. In this approach I've normally seen a custom database implemented to manage the reference data. The developer would then implement a custom data access method and a singleton which would be used to control access to the reference data. This is a pretty standard use of the singleton pattern. In this approach I think some of the considerations which need to be made are:
Sometimes I've seen an approach where a custom database has been implemented then a web service façade has been implemented on top of it. The web service will access the data and return it. In consuming this from BizTalk a C# assembly has been developed which uses the web service to get the reference data which is then consumed by a map.
In this approach I've normally seen it implemented in the same way as the singleton approach above. The key difference is that the reference data is usually held locally in a static hash table in the singleton approach where as in this approach the HttpCache object from the System.Web namespace is used. This gives a couple of options around a sliding and absolute expiration which will remove unused data from the cache helping to control the memory usage. You can also add one of the .net cache dependency objects which would allow you a way to detect changed and refresh the cache.
Enterprise Library has a caching block which provides a number of features which could help you solve this problem. One of the key benefits of enterprise library is that it supports different types of stores for the cached data including:
If I remember right the cache supports the same features as the HTTPCache approach which allows you to have a dependency and also expirations. There is an article at the following location which discusses using Enterprise Library Caching in BizTalk.
Enterprise Library can also integrate with external backing stores to support out of process caching.
One approach I quite like involves caching the data outside of the BizTalk process. This provides the benefit that you can cache without having to worry about the impact on the BizTalk process memory usage. There are a number of caching tools which you can use to help here such as:
Alachisoft offer an express version of their caching product which is free and a version for a relatively small cost which comes with some management tools for their distributed caching system.
Memcached is an open source distributed caching system. I know of some guys who have used this very successfully on a .net project with a major UK company.
Velocity is an initiative at Microsoft at present to create a distributed in memory caching platform. I feel that as this evolves it is important to keep an eye on this as it will in the future be likely to become the best approach to this.
These distributed caching systems offer the benefit of taking the memory usage out of your process, but offer fast access to the data via their API. Most of these products also offer high availability and synchronisation across a group of caches when you distribute them across your server group. I have in particular looked at NCache for this example and it is setup as a windows service which you would deploy on each BizTalk box. These services would then be configured to work as a cluster meaning they would synchronise themselves when changes were made.
Hopefully this article has highlighted the many options available when you are considering a caching solution to support your BizTalk implementation. There are many considerations which can be made and there isn't always a one size fits all rule like in most design decisions. I think some of the things that stand out from this discussion are that most of the approaches above always end up using a custom database to manage the reference data. I think in a future post I will look at how to combine some of the approaches discussed here with the BizTalk Cross Referencing features to produce a fairly simple yet effective combination of all of the approaches.
Print | posted on Sunday, September 21, 2008 7:42 PM |
Filed Under [
BizTalk
] | http://geekswithblogs.net/michaelstephenson/archive/2008/09/21/125352.aspx | crawl-002 | en | refinedweb |
Intro
hiccup is an interpreter for a subset of tcl.
New Features
- vwait works
- format and interp have basic functionality (interp -safe mostly works)
- expr works as expected, is efficient, and is supported in conditionals. Also, ternary ifs now work.
- apply and lmap have been added
- Floating point is supported natively (as in, not by constantly reparsing strings)
- {*} works.
- Arrays work
- Namespaces are supported (including 'export', 'import', and 'forget')
- switch is fully supported
- non-naive list handling
- Basic support for file channels has been added. Now files can be opened, closed, read from, written to, and appended.
- Procs can now have optional arguments. The 'args' parameter is also supported.
- Thanks to Haskell's laziness, hiccup does some pseudo-shimmering and memoizes parsing. As a result, things are about 30% faster.
- The REPL now uses readline.
- Error messages are much more consistent and useful, and it is significantly harder to create an error that will crash the interpreter.
Background
hiccup was mostly inspired by picol. picol is a neat little tcl subset interpreter in 550 lines of C. I'd been looking for a language to implement in haskell, and picol made me wonder, "Can I make a haskell interpreter that is just as speedy or speedier with less lines?". I was pretty sure the answer would be "Yes", since haskell has the benefit of more libraries and abstractions, and it seems I was mostly right. hiccup had well under 300 lines of code, and I think (minus type declarations, whitespace, comments, tests, and includes :-P ) it still does, despite my compulsion to add random library functions here and there.
I didn't know tcl when I started, so it was also a lovely exercise in learning the language. As I went along, I discovered that the fundamentals of the language are pretty elegant, but most practical things involve messy details that I don't care enough to implement. I'd like to stress that hiccup isn't a complete tcl interpeter, and it is not intended to be.
If anyone has any suggestions for improvements that are within the scope of what I was trying to do here (some basic features, keep it small and relatively efficient), I'd be very interested to hear. I'm looking at you, haskell gurus.
Note: The purpose of this thing wasn't to display my skill or advocate for haskell. It was a bit of fun in my idle time and an exploration of my interest in programming languages. Drawing any conclusions about haskell, tcl, me, or the nature of reality based on this would be silly. :)
Flaws
- interp is incomplete.
- Poor support for IO commands.. fconfigure, socket, fileevent not implemented yet.
- I made this in small blocks of otherwise idle time. I'm not a haskell expert, I'm not a tcl expert, and I wasn't trying all that hard. :-P
Features
- I'm unaware of any inconsistency with real Tcl in parsing or basic operations.
- Can easily be embedded in haskell programs and given custom commands.
- supports upvar, uplevel, and global
- Fairly complete namespace support
- allows ${bracket variable names}
- has puts, exit, eval, return, break, catch, continue, while, if, for, foreach, switch, source, append, split, time, srand, rand.. and more!
- supports lists, allows 'args' binding in method calls
- has some basic math stuff
- Supports some basic string, list, and array operations
- allows running with 'hiccup filename' or without argument as a repl
- various other things
Look at the stuff in the "atests" (acceptance tests) directory for more examples of functionality.
Future
- Soon
- namespace ensemble support
- ::tcl::string:: namespaces for ensembles, ::tcl::mathop, and similar
- Probably
- dict support
- chan ensemble (including reflectedchan)
- A way to extend it to allow user-created tcl types.
- Maybe
- Futures
- dict support
- A more sophisticated bytecode and compiler.
Example
# Here is an example of some stuff hiccup can do. # I think it's neat. namespace import ::tcl::mathop::* proc decr { v { i -1 } } { upvar $v loc incr loc $i } proc memfib x { set ::loc(0) 1 set ::loc(1) 1 for {set ctr 2} { $ctr <= $x } {incr ctr} { set v1 $::loc([- $ctr 1]) set v2 $::loc([- $ctr 2]) set {the sum} [+ $v1 $v2] set ::loc($ctr) ${the sum} } return $::loc($x) } set fcount 21 puts "First $fcount fibonacci numbers in descending order:" while { 2 <= $fcount } { puts -nonewline "[memfib $fcount] " decr fcount } puts "\nDone." proc say_i_havent_been_to { args } { foreach name $args { puts "I've never been to $name." } } say_i_havent_been_to Spain China Russia Argentina "North Dakota" proc is v { return $v } foreach num {0 1 2 3 4 5 6 7 8 9} { set type [switch -- $num { 1 - 9 {is odd} 2 - 3 - 5 - 7 {is prime} 0 - 4 - 6 - 8 {is even} default {is unknown} }] puts "$num is $type" } puts [expr { sin(4) + 44.5 + rand()}] | http://code.google.com/p/hiccup/ | crawl-002 | en | refinedweb |
XV is a Unix/X11-based image viewer/converter with some editing
capabilities. It has been distributed by John H. Bradley and the
University of Pennsylvania as (shared-source) shareware for the
last 15 years or so. Primary development appears to have ceased
as of early 1995, and all forms of maintenance seem to have ended
in 2000 or 2001; no part of the XV web site (trilon.com/xv) has
been updated since then, as far as I can determine. The author
does not respond to e-mail.
Last August, several input-validation vulnerabilities were described
on this list by "infamous41md / sean," together with an exploit for
one of them:
Various vendors, including Gentoo, SuSE, and OpenBSD, released
patches addressing the problems, but the patches were incomplete.
For example, the SuSE/Gentoo patch included this fragment (from):
--- xvpcx.c
+++ xvpcx.c Tue Aug 24 13:12:15 2004
@@ -222,7 +222,14 @@
byte *image;
/* note: overallocation to make life easier... */
- image = (byte *) malloc((size_t) (pinfo->h + 1) * pinfo->w + 16);
+ int count = (pinfo->h + 1) * pinfo->w + 16;
+
+ if (count <= 0 || pinfo->h <= 0 || pinfo->w <= 0) {
+ pcxError(fname, "Bogus PCX file!!");
+ return (0);
+ }
+
+ image = (byte *) malloc((size_t) count);
if (!image) FatalError("Can't alloc 'image' in pcxLoadImage8()");
xvbzero((char *) image, (size_t) ((pinfo->h+1) * pinfo->w + 16));
(This is within the 8-bit code.) Because of the additive factors,
count can be as large as 4295032848 == 65552 on machines with 32-bit
integers; obviously that's positive. Setting the height to 65536 and
the width to 65535 requires only 15 bytes of "fill" before the heap-
overflowing exploit code can presumably begin.
The more general case is in the 24-bit code, and it affects almost
all of the other 24-bit (RGB) formats, too:
@@ -250,17 +257,25 @@
{
byte *pix, *pic24, scale[256];
int c, i, j, w, h, maxv, cnt, planes, bperlin, nbytes;
+ int count;
w = pinfo->w; h = pinfo->h;
planes = (int) hdr[PCX_PLANES];
bperlin = hdr[PCX_BPRL] + ((int) hdr[PCX_BPRH]<<8);
+ count = w*h*planes;
+
+ if (count <= 0 || planes <= 0 || w <= 0 || h <= 0) {
+ pcxError(fname, "Bogus PCX file!!");
+ return (0);
+ }
+
/* allocate 24-bit image */
- pic24 = (byte *) malloc((size_t) w*h*planes);
+ pic24 = (byte *) malloc((size_t) count);
if (!pic24) FatalError("couldn't malloc 'pic24'");
- xvbzero((char *) pic24, (size_t) w*h*planes);
+ xvbzero((char *) pic24, (size_t) count);
maxv = 0;
pix = pinfo->pic = pic24;
In principle, "planes" can be as large as 255, but this function
isn't reached unless it's exactly equal to 3. That's more than
enough when w and h can each be as large as 65536, however. For
formats that support 32-bit width and height values, even 1-bit
images can cause wraparound to positive integers (which is what's
not addressed in the existing patches).
In general, the fix is to use additional variables to hold the
intermediate results of pairwise multiplication and to test that
the expected inverse arithmetic operations hold for the results.
Thus, for example, instead of malloc'ing a three-way product
directly:
foo = (char *) malloc((size_t) w*h*3); // int w, h;
...do something like this:
int npixels, bufsize;
npixels = w * h;
bufsize = 3 * npixels;
if (w <= 0 || h <= 0 || npixels/w != h || bufsize/3 != npixels) {
FAIL();
}
foo = (char *) malloc((size_t) bufsize);
I have incorporated such fixes into all affected XV image decoders
and updated my "jumbo patches" accordingly:
Since security fixes were/are not my primary motivation in making
the patches, they include many other things as well; I apologize
for that, but I don't have time to split things up and verify that
everything still works as pieces.
Bruno Rohee has tested several other image-manipulating applications
and found some of them to be affected, as well (though not necessarily
in an exploitable way):
GwenView (Unix/KDE)
IrfanView (Win32)
ImageMagick (various)
He also found that the GIMP and Imlib-based viewers appear NOT to
be affected.
CERT has assigned ID VU#622622 to this vulnerability. I have not
received any notice of a CVE identifier.
Regards,
--
Greg Roelofs newt pobox com
Newtware, PNG Group, AlphaWorld Map, etc. | http://seclists.org/bugtraq/2005/Apr/0145.html | crawl-002 | en | refinedweb |
Be.
Note that although this document is intended to deal with techniques which can be used when using mod_wsgi, many of the techniques are also directly transferable or adaptable to other web hosting mechanisms for WSGI applications.
When using mod_wsgi, unless you take specific action to catch exceptions and present the details in an alternate manner, the only place that details of uncaught exceptions will be recorded is in the Apache error log files. The Apache error log files are therefore your prime source of information when things go wrong.
Do note though that log messages generated by mod_wsgi are logged with various serverity levels and which ones will be output to the Apache error log files will depend on how Apache has been configured. The standard configuration for Apache has the LogLevel directive being set to 'warn'. With this setting any important error messages will be output, but informational messages generated by mod_wsgi which can assist in working out what it is doing are not. Thus, if new to mod_wsgi or trying to debug a problem, it is worthwhile setting the Apache configuration to use 'info' log level instead.
LogLevel info
If your Apache web server is only providing services for one host, it is likely that you will only have one error log file. If however the Apache web server is configured for multiple virtual hosts, then it is possible that there will be multiple error log files, one corresponding to the main server host and an additional error log file for each virtual host. Such a virtual host specific error log if one is being used, would have been configured through the placing of the Apache CustomLog directive within the context of the VirtualHost container.
Although your WSGI application may be hosted within a particular virtual host and that virtual host has its own error log file, some error and informational messages will still go to the main server host error log file. Thus you may still need to consult both error log files when using virtual hosts.
Messages of note that will end up in the main server host error log file include notifications in regard to initialisation of Python and the creation and destruction of Python sub interpreters, plus any errors which occur when doing this.
Messages of note that would end up in the virtual host error log file, if it exists, include details of uncaught Python exceptions which occur when the WSGI application script is being loaded, or when the WSGI application callable object is being executed.
Messages that are logged by a WSGI application via the 'wsgi.errors' object passed through to the application in the WSGI environment are also logged. These will got to the virtual host error log file if it exists, or the main error log file if the virtual host is not setup with its own error log file. Thus, if you want to add debugging messages to your WSGI application code, you can use 'wsgi.errors' in conjunction with the 'print' statement as shown below:
def application(environ, start_response):
status = '200 OK'
output = 'Hello World!'
print >> environ['wsgi.errors'], "application debug #1"
response_headers = [('Content-type', 'text/plain'),
('Content-Length', str(len(output)))]
start_response(status, response_headers)
print >> environ['wsgi.errors'], "application debug #2"
return [output]
If 'wsgi.errors' is not available to the code which needs to output log messages, then it should explicitly direct output from the 'print' statement to 'sys.stderr'.
import sys
def function():
print >> sys.stderr, "application debug #3"
...
If sys.stderr or sys.stdout is used directly then these messages will end up in the main server host error log file and not that for the virtual host unless the WSGI application is running in a daemon process specifically associated with a virtual host.
Do be aware though that writing to sys.stdout is by default restricted and will result in an exception occurring of the form:
IOError: sys.stdout access restricted by mod_wsgi.
import sys
sys.stdout = sys.stderr
In general, a WSGI application should always endeavour to only log messages via the 'wsgi.errors' object that is passed through to a WSGI application in the WSGI environment. This is because this is the only way of logging messages for which there is some guarantee that they will end up in a log file that you might have access to if using a shared server.
An application shouldn't however cache 'wsgi.errors' and try to use it outside of the context of a request. If this is done an exception will be raised indicating that the request has expired and the error log object is now invalid.
That messages output via sys.stderr and sys.stdout end up in the Apache error logs at all is provided as a convenience but there is no requirement in the WSGI specification that they are valid means of a WSGI application logging messages.
When a WSGI application is invoked, the request headers are passed as CGI variables in the WSGI environment. The dictionary used for this also holds information about the WSGI execution environment and mod_wsgi. When returning a response from a WSGI application, the status and response headers are passed back as arguments to the 'start_response()' callable originally passed to the WSGI application.
When debugging an application, it can be useful to be able to log what values are passed for each of these. This can be done using a simple WSGI middleware that wraps your WSGI application.
import pprint
class LoggingMiddleware:
def __init__(self, application):
self.__application = application
def __call__(self, environ, start_response):
errors = environ['wsgi.errors']
pprint.pprint(('REQUEST', environ), stream=errors)
def _start_response(status, headers):
pprint.pprint(('RESPONSE', status, headers), stream=errors)
return start_response(status, headers)
return self.__application(environ, _start_response)
def application(environ, start_response):
...
application = LoggingMiddleware(application)
The output from the middleware would end up in the Apache error log for the virtual host, or if no virtual host specific error log file, in the main Apache error log file.
For more complicated problems it may also be necessary to track both the request and response content as well. A more complicated middleware which can log these as well as header information to the file system is as follows:
import threading
import pprint
import time
import os
class LoggingInstance:
def __init__(self, start_response, oheaders, ocontent):
self.__start_response = start_response
self.__oheaders = oheaders
self.__ocontent = ocontent
def __call__(self, status, headers, exc_info=None):
pprint.pprint((status, headers, exc_info), stream=self.__oheaders)
self.__oheaders.close()
self.__write = self.__start_response(status, headers, exc_info)
return self.write
def __iter__(self):
return self
def write(self, data):
self.__ocontent.write(data)
self.__ocontent.flush()
return self.__write(data)
def next(self):
data = self.__iterable.next()
self.__ocontent.write(data)
self.__ocontent.flush()
return data
def close(self):
if hasattr(self.__iterable, 'close'):
self.__iterable.close()
self.__ocontent.close()
def link(self, iterable):
self.__iterable = iter(iterable)
class LoggingMiddleware:
def __init__(self, application, savedir):
self.__application = application
self.__savedir = savedir
self.__lock = threading.Lock()
self.__pid = os.getpid()
self.__count = 0
def __call__(self, environ, start_response):
self.__lock.acquire()
self.__count += 1
count = self.__count
self.__lock.release()
key = "%s-%s-%s" % (time.time(), self.__pid, count)
iheaders = os.path.join(self.__savedir, key + ".iheaders")
iheaders_fp = file(iheaders, 'w')
icontent = os.path.join(self.__savedir, key + ".icontent")
icontent_fp = file(icontent, 'w+b')
oheaders = os.path.join(self.__savedir, key + ".oheaders")
oheaders_fp = file(oheaders, 'w')
ocontent = os.path.join(self.__savedir, key + ".ocontent")
ocontent_fp = file(ocontent, 'w+b')
errors = environ['wsgi.errors']
pprint.pprint(environ, stream=iheaders_fp)
iheaders_fp.close()
length = int(environ.get('CONTENT_LENGTH', '0'))
input = environ['wsgi.input']
while length != 0:
data = input.read(min(4096, length))
if data:
icontent_fp.write(data)
length -= len(data)
else:
length = 0
icontent_fp.flush()
icontent_fp.seek(0, os.SEEK_SET)
environ['wsgi.input'] = icontent_fp
iterable = LoggingInstance(start_response, oheaders_fp, ocontent_fp)
iterable.link(self.__application(environ, iterable))
return iterable
def application(environ, start_response):
...
application = LoggingMiddleware(application, '/tmp/wsgi')
For this middleware, the second argument to the constructor should be a preexisting directory. For each request four files will be saved. These correspond to input headers, input content, response status and headers, and request content.
The WSGI specification allows any iterable object to be returned as the response, so long as the iterable yields string values. That this is the case means that one can too easily return an object which satisfies this requirement but has some sort of performance related issue.
The worst case of this is where instead of returning a list containing strings, a single string is returned. The problem with a string is that when it is iterated over, a single character of the string is yielded each time. In other words, a single character is written back to the client on each loop, with a flush occuring in between to ensure that the character has actually been written and isn't just being buffered.
Although for small strings a performance impact may not be noticed, if returning large strings the affect on request throughput could be quite significant.
Another case which can cause problems is to return a file like object. For iteration over a file like object, typically what can occur is that a single line within the file is returned each time. If the file is a line oriented text file where each line is a of a reasonable length, this may be okay, but if the file is a binary file there may not actually be line breaks within the file.
For the case where file contains many short lines, throughput would be affected much like in the case where a string is returned. For the case where the file is just binary data, the result can be that the complete file may be read in on the first loop. If the file is large, this could cause a large transient spike in memory usage. Once that memory is allocated, it will then be retained by the process, albeit that it may be reused by the process at a later point.
Because of the performance impacts in terms of throughput and memory usage, both these cases should be avoided. For the case of returning a string, it should be returned with a single element list. For the case of a file like object, the 'wsgi.file_wrapper' extension should be used, or a wrapper which suitably breaks the response into chunks.
In order to identify where code may be inadvertantly returning such iterable types, the following code can be used.
import types
import cStringIO
import socket
import StringIO
BAD_ITERABLES = [
cStringIO.InputType,
socket.SocketType,
StringIO.StringIO,
types.FileType,
types.StringType,
]
class ValidatingMiddleware:
def __init__(self, application):
self.__application = application
def __call__(self, environ, start_response):
errors = environ['wsgi.errors']
result = self.__application(environ, start_response)
value = type(result)
if value == types.InstanceType:
value = result.__class__
if value in BAD_ITERABLES:
print >> errors, 'BAD ITERABLE RETURNED: ',
print >> errors, 'URL=%s ' % environ['REQUEST_URI'],
print >> errors, 'TYPE=%s' % value
return result
def application(environ, start_response):
...
application = ValidatingMiddleware(application)
Because mod_wsgi only logs details of uncaught exceptions to the Apache error log and returns a generic HTTP 500 "Internal Server Error" response, if you want the details of any exception to be displayed in the error page and be visible from the browser, you will need to use a WSGI error catching middleware component.
One example of WSGI error catching middleware is the ErrorMiddleware class from Paste. This class can be configured not only to catch exceptions and present the details to the browser in an error page, it can also be configured to send the details of any errors in email to a designated recipient, or log the details to an alternate log file.
Being able to have error details sent by email would be useful in a production environment or where your application is running on a web hosting environment and the Apache error logs would not necessarily be closely monitored on a day to day basis. Enabling of that particular feature though should possibly only be done when you have some confidence in the application else you might end up getting inundated with emails.
To use the error catching middleware from Paste you simply need to wrap your existing application with it such that it then becomes the top level application entry point.
def application(environ, start_response):
status = '200 OK'
output = 'Hello World!\n\n'
response_headers = [('Content-type', 'text/plain'),
('Content-Length', str(len(output)))]
start_response(status, response_headers)
return [output]
from paste.exceptions.errormiddleware import ErrorMiddleware
application = ErrorMiddleware(application, debug=True)
In addition to displaying information about the Python exception that has occurred and the stack traceback, this middleware component will also output information about the WSGI environment such that you can see what was being passed to the WSGI application. This can be useful if the cause of any problem was unexpected values passed in the headers of the HTTP request.
Note that error catching middleware is of absolutely no use for trying to capture and display in the browser any errors that occur at global scope within the WSGI application script when it is being imported. Details of any such errors occuring at this point will only be captured in the Apache error log files. As much as possible you should avoid performing complicated tasks when the WSGI application script file is being imported, instead you should only trigger such actions the first time a request is received. By doing this you will be able to capture errors in such initialisation code with the error catching middleware.
Also note that the debug mode whereby details are displayed in the browser should only be used during development and not in a production system. This is because details which are displayed may be of use to anyone who may wish to compromise your site.
Python debuggers such as implemented by the 'pdb' module can sometimes be useful in debugging Python applications, especially where there is a need to single step through code and analyse application state at each point. Use of such debuggers in web applications can be a bit more tricky than normal applications though and especially so with mod_wsgi.
The problem with mod_wsgi is that the Apache web server can create multiple child processes to respond to requests. Partly because of this, but also just to prevent problems in general, Apache closes off standard input at startup. Thus there is no actual way to interact with the Python debugger module if it were used.
To get around this requires having complete control of the Apache web server that you are using to host your WSGI application. In particular, it will be necessary to shutdown the web server and then startup the 'httpd' process explicitly in single process debug mode, avoiding the 'apachectl' management application altogether.
$ apachectl stop
$ httpd -X
If Apache is normally started as the 'root' user, this also will need to be run as the 'root' user otherwise the Apache web server will not have the required permissions to write to its log directories etc.
The result of starting the 'httpd' process in this way will be that the Apache web server will run everything in one process rather than using multiple processes. Further, it will not close off standard input thus allowing the Python debugger to be used.
Do note though that one cannot be using the ability of mod_wsgi to run your application in a daemon process when doing this. The WSGI application must be running within the main Apache process.
To trigger the Python debugger for any call within your code, the following customised wrapper for the 'Pdb' class should be used:
class Debugger:
def __init__(self, object):
self.__object = object
def __call__(self, *args, **kwargs):
import pdb, sys
debugger = pdb.Pdb()
debugger.use_rawinput = 0
debugger.reset()
sys.settrace(debugger.trace_dispatch)
try:
return self.__object(*args, **kwargs)
finally:
debugger.quitting = 1
sys.settrace(None)
This might for example be used to wrap the actual WSGI application callable object.
def application(environ, start_response):
status = '200 OK'
output = 'Hello World!\n\n'
response_headers = [('Content-type', 'text/plain'),
('Content-Length', str(len(output)))]
start_response(status, response_headers)
return [output]
application = Debugger(application)
When a request is now received, the Python debugger will be triggered and you can interactively debug your application from the window you ran the 'httpd' process. For example:
> /usr/local/wsgi/scripts/hello.py(21)application()
-> status = '200 OK'
(Pdb) list
16 finally:
17 debugger.quitting = 1
18 sys.settrace(None)
19
20 def application(environ, start_response):
21 -> status = '200 OK'
22 output = 'Hello World!\n\n'
23
24 response_headers = [('Content-type', 'text/plain'),
25 ('Content-Length', str(len(output)))]
26 start_response(status, response_headers)
(Pdb) print start_response
<built-in method start_response of mod_wsgi.Adapter object at 0x1160180>
cont
When wishing to allow the request to complete, issue the 'cont' command. If wishing to cause the request to abort, issue the 'quit' command. This will result in a 'BdbQuit' exception being raised and would result in a HTTP 500 "Internal Server Error" response being returned to the client. To kill off the whole 'httpd' process, after having issued 'cont' or 'quit' to exit the debugger, interrupt the process using 'CTRL-C'.
To see what commands the Python debugger accepts, issue the 'help' command and also consult the documentation for the 'pdb' module on the Python web site.
Note that the Python debugger expects to be able to write to sys.stdout to display information to the terminal. Thus if using using a Python web framework which replaces sys.stdout such as web.py, you will not be able to use the Python debugger.
In order to use the Python debugger modules you need to have direct access to the host and the Apache web server that is running your WSGI application. If your only access to the system is via your web browser this makes the use of the full Python debugger impractical.
An alternative to the Python debugger modules which is available is an extension of the WSGI error catching middleware previously described. This is the EvalException class from Paste. It embodies the error catching attributes of the ErrorMiddleware class, but also allows some measure of interactive debugging and introspection through the web browser.
As with any WSGI middleware component, to use the class entails creating a wrapper around the application you wish to debug.
def application(environ, start_response):
status = '200 OK'
output = 'Hello World!\n\n'
response_headers = [('Content-type', 'text/plain'),
('Content-Length', str(len(output)))]
start_response(status, response_headers)
return [output]
from paste.evalexception.middleware import EvalException
application = EvalException(application)
Like ErrorMiddleware when an unexpected exception occurs a web page is presented which shows the location of the error along with the contents of the WSGI application environment. Where EvalException is different however is that it is possible to inspect the local variables residing within each stack frame down to where the error occurred. Further, it is possible to enter Python code which can be evaluated within the context of the selected stack frame in order to access data or call functions or methods of objects.
In order for this to all work requires that subsequent requests back to the WSGI application always end up with the same process where the error originally occurred. With mod_wsgi this does however present a bit of a problem as Apache can create and use multiple child processes to handle requests.
Because of this requirement, if you want to be able to use this browser based interactive debugger, if running your application in embedded mode of mod_wsgi, you will need to configure Apache such that it only starts up one child process to handle requests and that it never creates any additional processes. The Apache configuration directives required to achieve this are as follows.
StartServers 1
ServerLimit 1
The directives must be placed at global scope within the main Apache configuration files and will affect the whole Apache web server.
If you are using the worker MPM on a UNIX system, restricting Apache to just a single process may not be an issue, at least during development. If however you are using the prefork MPM on a UNIX system, you may see issues if you are using an AJAX intensive page that relies on being able to execute parallel requests, as only one request at a time will be able to be handled by the Apache web server.
If using Apache 2.X on a UNIX system, a better approach is to use daemon mode of mod_wsgi and delegate your application to run in a single daemon process. This process may be single or multithreaded as per any threading requirements of your application.
Which ever configuration is used, if the browser based interactive debugger is used it should only be used on a development system and should never be deployed on a production system or in a web hosting environment. This is because the debugger will allow one to execute arbitrary Python code within the context of your application from a remote client.
In cases where Apache itself crashes for no apparent reason, the above techniques are not always particularly useful. This is especially the case where the crash occurs in non Python code outside of your WSGI application.
The most common cause of Apache crashing, besides any still latent bugs that may exist in mod_wsgi, of which hopefully there aren't any, are shared library version mismatches. Another major cause of crashes is third party C extension modules for Python which are not compatible with being used in a Python sub interpreter which isn't the first interpreter created when Python is initialised, or modules which are not compatible with Python sub interpreters being destroyed and the module then being used in a new Python sub interpreter.
Examples of where shared library version mismatches are known to occur are between the version of the 'expat' library used by Apache and that embedded within the Python 'pyexpat' module. Another is between the version of the MySQL client libraries used by PHP and the Python MySQL module.
Both these can be a cause of crashes where the different components are compiled and linked against different versions of the shared library for the packages in question. It is vitally important that all packages making use of a shared library were compiled against and use the same version of a shared library.
Another problematic package is Subversion. In this case there can be conflicts between the version of Subversion libraries used by mod_dav_svn and the Python Subversion bindings. Certain versions of the Python Subversion modules also cause problems because they appear to be incompatible with use in a Python sub interpreter which isn't the first interpreter created when Python is initialised.
In this latter issue, the sub interpreter problems can often be solved by forcing the WSGI application using the Python Subversion modules to run in the '%{GLOBAL}' application group. This solution often also resolves issues with SWIG generated bindings, especially where the '-thread' option was supplied to 'swig' when the bindings were generated.
Whatever the reason, in some cases the only way to determine why Apache or Python is crashing is to use a C code debugger such as 'gdb'. Now although it is possible to attach 'gdb' to a running process, the preferred method for using 'gdb' in conjunction with Apache is to run Apache in single process debug mode from within 'gdb'.
To do this it is necessary to first shutdown Apache. The 'gdb' debugger can then be started against the 'httpd' executable and then the process started up from inside of 'gdb'.
$ /usr/local/apache/bin/apachectl stop
$ sudo gdb /usr/local/apache/bin/httpd) run -X
Starting program: /usr/local/apache/bin/httpd -X
Reading symbols for shared libraries .+++ done
Reading symbols for shared libraries ..................... done
If Apache was crashing on startup, you should immediately encounter the error, otherwise use your web browser to access the URL which is causing the crash to occur. You can then commence trying to debug why the crash is occuring.
Note that you should ensure that you have not assigned your WSGI application to run in a mod_wsgi daemon process using the WSGIDaemonProcess and WSGIProcessGroup directives. This is because the above procedure will only catch crashes which occur when the application is running in embedded mode. If it turns out that the application only crashes when run in mod_wsgi daemon mode, an alternate method of using 'gdb' will be required.
In this circumstance you should run Apache as normal, but ensure that you only create one mod_wsgi daemon process and have it use only a single thread.
WSGIDaemonProcess debug threads=1
WSGIProcessGroup debug
If not running the daemon process as a distinct user where you can tell which process it is, then you will also need to ensure that Apache LogLevel directive has been set to 'info'. This is to ensure that information about daemon processes created by mod_wsgi are logged to the Apache error log. This is necessary, as you will need to consult the Apache error logs to determine the process ID of the daemon process that has been created for that daemon process group.
mod_wsgi (pid=666): Starting process 'debug' with threads=1.
Knowing the process ID, you should then run 'gdb', telling it to attach directly to the daemon process.
$ sudo gdb /usr/local/apache/bin/httpd 666) cont
Continuing.
Once 'gdb' has been started and attached to the process, then initiate the request with the URL that causes the application to crash.
Attaching to the running daemon process can also be useful where a single request or the whole process is appearing to hang. In this case one can force a stack trace to be output for all running threads to try and determine what code is getting stuck. The appropriate gdb command in this instance is 'thread apply all bt'.
sudo gdb /usr/local/apache-2.2/bin/httpd 666
GNU gdb 6.3.50-20050815 (Apple version gdb-477) (Sun Apr 30 20:06:22) thread apply all bt
Thread 4 (process 666 thread 0xd03):
#0 0x9001f7ac in select ()
#1 0x004189b4 in apr_pollset_poll (pollset=0x1894650,
timeout=-1146117585187099488, num=0xf0182d98, descriptors=0xf0182d9c)
at poll/unix/select.c:363
#2 0x002a57f0 in wsgi_daemon_thread (thd=0x1889660, data=0x18895e8)
at mod_wsgi.c:6980
#3 0x9002bc28 in _pthread_body ()
Thread 3 (process 666 thread 0xc03):
#0 0x9001f7ac in select ()
#1 0x0041d224 in apr_sleep (t=1000000) at time/unix/time.c:246
#2 0x002a2b10 in wsgi_deadlock_thread (thd=0x0, data=0x2aee68) at
mod_wsgi.c:7119
#3 0x9002bc28 in _pthread_body ()
Thread 2 (process 666 thread 0xb03):
#0 0x9001f7ac in select ()
#1 0x0041d224 in apr_sleep (t=299970002) at time/unix/time.c:246
#2 0x002a2dec in wsgi_monitor_thread (thd=0x0, data=0x18890e8) at
mod_wsgi.c:7197
#3 0x9002bc28 in _pthread_body ()
Thread 1 (process 666 thread 0x203):
#0 0x900c7060 in sigwait ()
#1 0x0041ba9c in apr_signal_thread (signal_handler=0x2a29a0
<wsgi_check_signal>) at threadproc/unix/signals.c:383
#2 0x002a3728 in wsgi_start_process (p=0x1806418, daemon=0x18890e8)
at mod_wsgi.c:7311
#3 0x002a6a4c in wsgi_hook_init (pconf=0x1806418, ptemp=0x0,
plog=0xc8, s=0x18be8d4) at mod_wsgi.c:7716
#4 0x0000a5b0 in ap_run_post_config (pconf=0x1806418, plog=0x1844418,
ptemp=0x180e418, s=0x180da78) at config.c:91
#5 0x000033d4 in main (argc=3, argv=0xbffffa8c) at main.c:706
It is suggested when trying to debug such issues that the daemon process be made to run with only a single thread. This will reduce how many stack traces one needs to analyse. | http://code.google.com/p/modwsgi/wiki/DebuggingTechniques | crawl-002 | en | refinedweb |
)
Important: This is an old version of this page. For the latest version, use the links in the left-side navbar..
This document is intended for programmers who want to write client applications that can interact with contacts.
It's a reference document; it assumes that you understand the concepts presented in the developer's guide, and the general ideas behind the Google Data APIs protocol..
Although the examples in this document use only the
full projection, there are some other useful projections.
The following table describes the supported projection values:
The Contacts Data API supports the following standard Google Data API query parameters:
For more information about the standard parameters, see the Google Data APIs protocol reference document.
In addition to the standard query parameters, the Contacts Data API supports the following parameters:.
XML namespace URL for
gContact:.
In this namespace, an element is defined that represents a group to which the contact belongs.
Contact was deleted from the group and is in group:
<gContact:groupMembershipInfo <gContact:groupMembershipInfo
contactGroup = element atom:entry { atomCategory, atomUpdated, atomTitle, atomContent, element gd:deleted?, element gd:extendedProperty*, systemGroup? }
The table below details contact groups schema:
There is a limited set of possible values for the
id attribute
of the
gContact:systemGroup element. These values are enumerated
in the table below:>
Using the feed for contact groups one can use all of the query parameters available for the contact feed (see: Contacts query parameters reference) except for the
group parameter. | http://code.google.com/apis/contacts/docs/2.0/reference.html | crawl-002 | en | refinedweb |
According to the Burton Group’s research, Prototype is the most used framework for Ajax development. In the survey of 488 Ajax developers conducted by Burton Group, the most popular libraries and frameworks ranked as follows:
Prototype 26.6%
script.aculo.us 19.5%
DWR 14.8%
Dojo 11.1%
Ruby on Rails 10.0%
Rico 6.8%
Ajax.NET 6.8%
Sajax 5.7%
xajax 3.3%
Prototype is leading with 26.6% share and it is used by script.aculo.us and Rico frameworks. Again, Ruby on Rails uses script.aculo.us which is based on Prototype. So together Prototype share is more than 70%. Currently I am using Dojo framework and its market share is way below the Prototype share. Dojo’s packaging system, UI widgets(like Rich Text editor) and its event system makes Dojo as a well engineered framework. I also like its IFrame workaround for back button support. Having these unique features why Dojo is behind the others? Is it because of its heaviness or complexity? Or some thing else?
Also whats the best Ajax framework/toolkit in your perspective? Share your thoughts!!!
personally i think prototype is very light as compared to dojo and is not a full framework. prototype/rico is more of utility.. in my opinion with a few widgets etc..
I guess people are using it for any quick AJAX decorations on their website. But if you need to start from scratch, i would say- Dojo is the way to go..
I like using dwr, even with its shortcomings. It has some good Spring integration and is easy to integrate into a Java web application. That made it fit in very well into my current work environment.
I am personally using Dojo for all my javascript needs on the Something Awful forums, perhaps you've heard of them? Prototype tends to collide with javascript a little more than I'd like, and puts new things in the global namespace, such as the $() shortcut for document.getElementById(). Dojo is better about this sort of thing and stays inside of its own namespace (it's equivalent function is dojo.byId()).
It's hard work running a forum. I do my best to maintain at least 75% uptime though.
I use Prototype and rather build all my widgetry myself. I like having a "dumb" library at hands and utilize it to build my own applications, because then I can more easilly get the accessibility and validity of my applications right.
I also use Yahoo's Event library which raises event-based programming to a completely new level. I have no idea how I managed to live without it before.
Dojo is a terrific toolkit that has suffered from a lack of documentation over the past year and poor management. The lack of documentation makes the learning curve incredibly long and not cost effective to implement..
SitePen hardly generates much of its income from Dojo training and support. I find it amusing when people post information without knowing what they are talking about.
We certainly have never intentionally withheld information about Dojo. The new version of Dojo has a nice documentation tool, | http://www.oreillynet.com/xml/blog/2006/07/whats_the_best_ajax_toolkitfra.html | crawl-002 | en | refinedweb |
DRM and the Web
Rigo Wenning
ODRL Workshop
Vienna, 22-23 April 2004
Rigo Wenning
<rigo@w3.org>
W3C/ERCIM
Sophia Antipolis, France
Plan
Expectations
Integration and Interoperability
ID issues
Enhancements and constraints
DRM and Privacy
DRM and Web Services
DRM and P2P
Expectations
EC IST mentions lack of DRM as a roadblock?
iTunes works!
Piracy is (the only) reason for bad business in the music sector?
Voices talk about high prices for bad food!
Real issues
Is the Privacy-issue solved?
Does DRM integrate well into other DRM and into applications?
Is there a solution to the issue that a digital copy can't be distinguished from its original?
Is DRM something that the Web Services Arena should think about?
What about P2P?
The war is still going on
Heavy lobbying to preserve a business model, where content is attached to tangible goods.
Erosion of exceptions to copyright and Droit d'auteur
P2P is getting more sophisticated and more of a closed group
P2P starts using signature - mechanisms.
DRM and the war
As long as the war is going on, DRM - Schemes have uncertainety about the semantics to use.
In presence of unsecure semantics, application semantics are used.
This will create a potential conflict with ever changing legal semantics.
ODRL?
ODRL is a framework to express semantics
ODRL is not application semantics as it is a framework
ODRL just perpetuates the semantic trouble
ODRL will have to offer profiles to allow certainty
Missing Semantics?
ODRL has a fairly complete set of semantics
But it is missing the logical NOT
NOT can be expressed with AND plus OR, but it gets more complicated
Example for NOT
Try to encode this simple sentence in ODRL:
You can do whatever you want with my work, but if you make money with it, give me 15%
ODRL says:
A Permission that is not specified in any Rights Expressions is not granted.
Conclusion o(n/r) NOT:
ODRL is missing a wildcard mechanism or a NOT
The more constraints on copyright, the simpler the expression in ODRL
Creative Commons is exactly the opposite
Interoperability and Integration
Interoperability with other DRM languages
Interoperability with the Web
Other Languages
Treat with both sides of the war:
Interoperability with MPEG-21
Interoperability with Creative Commons
This has be explored but can not be considered done
Integration with the Web
Difficult integration into HTML
Would need some binding mechanisms like in P3P
Bind DRM to HTTP (URI) or to HTML (link rel?)
ID Issues
One of the various splits at the W3C DRM Workshop was the identification of objects
This was also marked in the Team comment
There is still a profile missing on how to use URI's to identify a protected work just in any namespace.
DRM and Privacy
A big issue in the W3C DRM Workshop, especially for the enforcement engine
Privacy is still a big issue
Privacy might be misused as a term for general dissatisfaction
ODRL and Privacy
Currently search for
Privacy
in ODRL gives
one
hit
P3P 1.1 is developing a generic p3p attribute to bind a P3P Policy to a specific XML Element
ODRL could use that solution to address privacy in a much better way.
DRM and Web Services
DRM is just yet another set of metadata
DRM should integrate into the Web Services Model
SOAP and WSDL contain an advanced failure mechanism that could be used.
ODRL and Web Services
ODRL is not defining a protocol but contains a binding
The binding could be used to mix in to WSDL
A Profile or Note would be nice
DRM and P2P
Sounds like natural enemies, but it isn't
DRM would allow to legitimize some of the P2P activities
Psychology is key (see War above)
Initiatives are missing to integrate effective DRM
ODRL and P2P
Keep away from good/bad paradigms
adjust your attacker model
give people who want to do the right thing the opportunity to do the right thing, not just throw away the data
DRM and Exceptions
Risk of losing our history
Does DRM generate a right to hack for history?
Library Privileges are not implemented yet
Keep Society and the needs of a democratic society in mind while designing DRM.
ODRL and Exceptions
This is still the weak point of ODRL and I still hope for a revision
Missing wild cards and NOT-operator
There is still research ahead
The exceptions show a lot about the spirit of design
Merci bien
I hope I gave you some points for discussion
Presentation is available on the Web | http://www.w3.org/Talks/2004/04-odrl/ | crawl-002 | en | refinedweb |
Last update: Jan-30-02
1. TMX
1.1. Purpose
1.2. Stage
1.3. Maintaining Organization
1.4. Relevance to the W3C
2. TBX
2.1. Purpose
2.2. Stage
2.3. Maintaining Organization
2.4. Relevance to the W3C
3. OLIF
3.1. Purpose
3.2. Stage
3.3. Maintaining Organization
3.4. Relevance to the W3C
4. XLIFF
4.1. Purpose
4.2. Stage
4.3. Maintaining Organization
4.4. Relevance to the W3C
5. Summary
5.1. Language/Locale Identification
5.2. Localization Properties of XML Formats
5.3. Localization Namespace
TMX is the Translation Memory eXchange format.
Web site:.
Allows the transfer of translation memories between from a translation tool to another. A translation memory (TM) is a collection of source entries with their translations in one or more target languages.
Example: TMXExample.xml
(normally the file uses a
.tmx extension).
Version 1.3 was released on August 29th 2001.
The format is implemented, at various degrees, by most translation and localization tools.
The OSCAR Special Interest Group at LISA (the Localisation Industry Standards Association).
Only relatively relevant. One of the main common areas of interest is the
definition of a set of proper identifier for languages. Currently TMX uses
xml:lang
but the consensus is that the values do not cover all necessary
languages/locales (for example, Latin-American Spanish). OSCAR has a
sub-committee on this topic.
TBX is the TermBase eXchange format. It is also known as
DXLT (Default XLT format (XLT: XML representations of Lexicons and
Terminologies)).
Web site:.
Allows the transfer of glossaries between from translation tool to another. The format is based on ISO 12200: MARTIF (Machine-Readable Terminology Interchange Format).
Example: TBXExample.xml
(normally the file uses a
.tbx extension).
Still at a draft stage, but well advanced.
SALT (Standards-based Access service to multilingual Lexicons and Terminologies) at BYU.
Only relatively relevant. Currently TBX uses a
lang attribute,
it plans to uses
xml:lang but the consensus is that the values do
not cover all necessary languages/locales (for example, Latin-American Spanish).
OLIF is the Open Lexicon Interchange Format.
Web site:.
Allows the transfer of terminlogogical and lexical data between from translation tool to another. This is close to the same purpose as TBX, but OLIF is more geared toward NLP data (for example: Machine Translation lexicons). Designed for 6 languages for now.
Example: OLIFExample.xml.
Version 2.0 still at a draft stage, but well advanced.
The OLIF Consortium. (Note: the OLIF Consortium and the SALT group collaborate closely).
Only relatively relevant. One of the main common areas of interest is the
definition of a set of proper identifier for languages. Currently OLIF uses a
<language>
element and a
<geogUsage> element.
XLIFF is the XML Localisation Interchange File Format.
Web site:.
Allowing the transfer of localizable data extracted from various original files from one stage of the localization process to the next, up to merging the localized data back into its original format.
Example: XLIFFExample.xml
(normally the file uses a
.xlf extension).
Version 1.0 is within days to be moved as a Committee Specification, and to be submitted to be a OASIS Standard.
The XLIFF Technical Committee at OASIS.
There are several common area of interest:
xml:lang,
source-language, and
target-languagewith the same values as for
xml:lang.
maxwidth,
maxheight,
maxbytes, etc.). It would be very advantageous to have a standard way of defining such properties, either for a given vocabulary (along with the rule file or as part of the schema), as well as within any XML document (as a standard set of attributes and elements belonging to a reserved namespace). Many of the XLIFF attributes should have a counterpart in this namespace.
There are several areas where localization-related formats have currently a need for some kind of standardization that may be relevant for W3C work:
Need for a better mechanism to identify languages and/or locales. Several participants have express some ideas on this topic:
Need for a way to identify the localizable elements and attributes of an XML vocabulary. Several participants have express some ideas on this topic:
Need for a common way to provide additional localization-specific information within XML documents. Several participants have express some ideas on this topic: | http://www.w3.org/2002/02/01-i18n-workshop/LocFormats | crawl-002 | en | refinedweb |
PyRRD
PyRRD is a pure-Python OO wrapper for the RRDTool (round-robin database tool). The idea is to make RRDTool insanely easy to use and to be aesthetically pleasing for Python programmers.
Visit the wiki for more information, usage examples, and graphs.
Latest Changes in Trunk
- Added an RRD.fetch method
- Added support for reading RRD files from disk
- Added an RRD.info method
Latest Release
- Added support for Windows users
- Fixed some bugs in method signatures
PyRRD Quick Example
Here's what the OO wrapper lets you do:
from pyrrd import graph def1 = graph.DataDefinition(vname='downloads', rrdfile='downloads.rrd', ds_name='downloads', cdef='AVERAGE') area1 = graph.Area(value=def1.vname, color='#990033', legend='Downloads', stack=True) g = graph.Graph(path, imgformat='PNG', width=540, height=100, start="-%i" % YEAR, end=-1, vertical_label='Downloads/Day', title='Annual downloads', lower_limit=0) g.data.append(def1) g.data.append(area1) g.write() | http://code.google.com/p/pyrrd/ | crawl-002 | en | refinedweb |
Up to Design Issues.
I face these problems day to day, and like many geeks, am driven by the urge to make the boring things in life happen automatically, with the computer helping more effectively. There are lots of things I can do with N3 rules -- but I'd like to have a nice user interface to it which hides as much technology beneath the surface as possible. I'd like as many non-geeks as possible to be able to use the same tools.
Let's take one example. I took a bunch of photos of a local soccer team, once when they played Wayland, and once when they played Arlington. I loaded them all into iPhoto. I wanted to burn a CD for the team of the best of the bunch. I also want to be able to find them later.
On the first day, I didn't take any other photos, so the simplest thing was to make a 'smart folder' (actually 'smart Album' in iPhoto) , which had in it by definition the photos taken on that day. The smart folder allows you to specify a combination (and or or) a number of constraints such as time, keyword, text and rating. I called this one Soccer vs Wayland.
On the second day, I took other photos as well, so the smart folder was going to be more complicated. So instead, I just found all the photos, selected them, and dumped them in a new plain folder Soccer vs Arlington.
These of course one would represent in RDF as classes. - but we'll get into that later.
Ok, so here's where we get into wish-list territory.
1) At that point, I wanted to be able to make a virtual folder Soccer, and make the two folders subfolders. (There used to be a photo processing tool called Retriever which would handle hierarchical classifications well, but that I lost track of.) This would indicate that anything in either of the two Soccer subfolders was a member of the Soccer folder -- or was tagged 'soccer' if you like.
In fact, you can make a smart folder Soccer consisting of all the things which are either in Soccer vs Wayland or Soccer vs Arlington. You have to make it as a smart folder, which is not as intuitive, but woks fine. It doesn't give me the nice hierarchical user interface.
Actually I now want to associate some exportable re-usable data. The folder names are essentially my local tags. Exporting them doesn't help much.
Suppose, for example, I want to geotag the photos, so that I can find them on a map, or people interested in sports at the given field could find them. The current user interface allows me to select all the photos in one folder and apply keywords and apply metadata to them, as a batch operation. It is actually useful that the data is carefully stored in each photo, but it is sad that the fact that the metadata (such as a comment about the game) was applied to everything in the folder.
I'd like to be able to associate the random tag name I just made up with properties to be applied to each of the things tagged. Suppose at the user interface we introduce a label. A label is a set of common metadata that I want to apply to things at once.
The user interface could really milk the label metaphor, by representing a label as a box with a hole in the end with a bit of string. It clashes perhaps with the folder metaphor. If we use both, then I'd like to be able to drop a label on a folder, and let all the things in the folder inherit the labeled properties.
I'd like to see for each photo firstly what properties it has, but secondarily which labels and hence folder the properties came from.
The essential thing about a label is that as I build it, I am prompted to use shared ontologies. They could be group ontologies which others have exported, they could be globally understood ontologies like time and place, and email address of a person depicted. As I create the label from an (extendable) set of options in menus, and using drag and drop and other user interface tricks for noting relationships, I am creating data which will be much more useful than the tag. The tag then I can slap on very easily.
The hope is then that by making label creation something which is low cost, because I have to do it only once and can apply it many times, the incentive for me @@
In this section we leave the user interaction and discuss the way in which labels can be exchanged in RDF under the covers. This of course is important for interoperability. A label can be expressed in many ways. in bits on the wire. The label describes a set of things, which in RDF is a class*. Information about the class and the things in it -- the things labeled -- can be given in various ways.
As a rule, it could look like
{ ?x a soc:SoccerWaylandPhoto } => { ?x geo:approxLocation [ geo:lat 47. geo:long 78 ]; foaf:depicts soc:ourTeam. }
A label is a fairly direct use of OWL restrictions:
SoccerWaylandPhoto rdfs:subClassOf [ [ a owl:Restriction; owl:owl:onProperty geo:approxLocation; owl:hasValue [ geo:lat 47. geo:long 78 ]], [ a owl:Restriction; owl:onPredicate foaf:depicts; owl:allValuesFrom soc:ourTeam].
(Let's not discuss the modeling of depiction here, rather elsewhere.) This is very much the sort of thing OWL is designed for.
There is one trap which one must beware of. Remember that the label is a concept. It is a class. It isn't a photo. The label may have been created by someone, at a particular time, but that person and that time have nothing to do with the creator and time of a photo which is so labeled. You can not write
soc:SoccerWaylandPhoto geo:approxLocation [ geo:lat 47. geo:long 78 ]; foaf:depicts soc:ourTeam.
It is possible to make a special label terms which are only used only for labels:
soc:SoccerWaylandPhoto LAB:approxLocation [ geo:lat 47. geo:long 78 ]; LAB:depicts soc:ourTeam.
and have some metadata like
foaf:depicts ex:labelPredicate LAB:depicts. geo:approxLocation ex:labelPredicate LAB:approxLocation.
and a general rule like
{ ?x a ?lab. ?lab ?p ?z. ?p ex:labelPredicate ?q } => { ?x ?q ?z }.
or
{ ?lab ?p ?z. ?p ex:labelPredicate ?q } => { ?lab rdfs:subClassOf [ a owl:Restriction; owl:onProperty ?q; owl:hasValue ?z] }.
These methods are more or less inter-convertible. There are various communities which understand OWL and N3 rules, which may find those forms most convenient.
The architecture of this system then is that tags are initially local to the user. Anyone can use any word to to tag anything they want. Labels are used to associate meaning with them, but the tag itself is local.
Mapped into RDF, tags are classes in a local namespace. They can of course be shared. Tagging things with other people's tags attributes to them the properties associated with those tags, if any. Some people may define tags with rather loosely defined meaning, and no RDF labels, in which case others will be less inclined to use those tags.
When one combines a selection expression of a 'smart folder' with a label, then the result is a form of rule which is restricted to one variable. This can be expressed in OWL as a subclass relationship between restrictions.
A lot of information can be expressed as rules, but finding an intuitive user interface to allow lay users to express their needs with rules has been a stumbling block. These smart folder and label metaphors, combined, could be a route to solving this problem*.
There are many systems which use selection rules to define virtual sets of things. There probably lots which use an abstraction equivalent to labels.
One system which effectively uses labels is (I think) described as 'semantic folders' (@@link Lassila and Deepali), to be published
There is a language for labels being defined, as it happens, by the Web Content Labeling (WCL) Incubator Group at W3C. The final form of expression has not been decided.
The concept of a label as a preset set of data which is applied to things and classes of things provides an intuitive user interface for a operation which should be simple for untrained users.
Newman.R., Tag ontology design>, 2005-03-29.
Stefano Mazzochi,Folksologies: de-idealizing ontologies, 2005-05-05
Tom Gruber, Where the Social Web Meets the Semantic Web, Keynote, ISWC 2006. ( video)
W3C Content Label Incubator Group
Dan Connolly, Some test cases from WCL/POWDER work in N3.
*we do not here discuss the difference between rdfs:Class and owl:Class
How could other variables be added? Other variables can be expressed as paths from the base variable, and paths can be selected from a menu-like tree, and so on. The tabulator has a user interface for selecting a subgraph for a query. The smart folder selection panel could have the option for adding another similar panel for an item connected by a search path.
Up to Design Issues
Tim BL | http://www.w3.org/DesignIssues/TagLabel | crawl-002 | en | refinedweb |
pragmatic agility
Interesting bit of detective work the other day I thought I'd share with everyone. A friend of a friend was having trouble with an ASP 2.0 project that was ported to ASP.NET. Turns out that on some web servers the different clients were getting their data overwritten by others. A little splunking uncovered that the application was maintaining state using a public variable declared in a VB module. I could guess what was happening, but wanted to know the details so I created a tiny test app that looked like this:
Module Module1 Public moduleinteger As Integer End Module
I compiled and then decompiled the assembly into C# with the following results:
namespace ModuleTest { internal sealed class Module1 { public static int moduleinteger; } }
So essentially the vb compiler turns the module keyword into the c# equivalent "internal sealed class" and makes all public variable static. Also any refernece to the public module variable gets the "module" name added to it as well. And since static variables are the same across all threads any update to one, updates all.
This is actually the same behavior VB6 modules had, but apparently most VB6 developers never realized this since they worked primarily with Windows apps that serviced only one user at a time. I actually had a hard time tracking down an error in VB6 that resulted from this one time that a predecessor had did. Anyhow, this comes up often in the various forums, so its a rather significant stumbling block in ASP.NET for VB developers.
Well, I have come across this most disturbing phenomena and must say it is driving me insane. I am trying to create a set of "globally" accessible variables from within a page, and any user controls it contains without having to pass the variables back and forth betweent the calling page and the user controls each time.
Any Ideas as to how to make this happen, as using the public keyword seems to automatically make them static no matter what I say and screws up my pages between requests.
thanks
i was facing the problem of declaring public variables and their scope.. this help provide me to customize my apps.
chandan bhakuni
I don't beleive this is exactly the same problem as in VB6 (maybe Alex can convince me I am wrong). We had in VB6 this exact same problem only when we declared variables in a module Global the problem does not occur at our site when we use Public in VB6 modules.
hi
i m also facing the same problem(public variable being accessed by all the threads) ...
have you got any way to solve this problem.
its driving me crazy
Thanks in advance
Sivabalan K
The easiest way might be to use session variables or thread local storage. It depends on what your code is trying to do.
Pingback from session variable in vb net
Simply use the following way for storing and retrieving a value accross your ASP.NET pages:
*****Storing a value*****
session("myVariable") = "assign value here"
*****Retrieving a value*****
textbox1.text = session("myVariable")
Remember: By Default, these session variables lose their values after 20 minutes since this is the default timeout in ASP.NET. To change this timeout length, simply modify your web.config file accordingly.
Happy Coding!
Thank. I wanted to confirm my understanding of module variables. This post confirms that my understanding was perfect. | http://weblogs.asp.net/wallen/archive/2003/10/21/32854.aspx | crawl-002 | en | refinedweb |
ITWorx Geek
I was trying to include my ASP.NET MVC project in a TFS team build today but the build failed so I've investigated this issue and thought it will be helpful to share it with the community.
To get the MVC project build successfully with the team build make sure of the following:
- Your build server has the WebApplication targets file located in <Program Files> \MSBuild\Microsoft\Visual Studio\v9.0\WebApplications , if not . copy this file from your development machine to the same path in the build server.
- You have installed ASP.NET MVC framework in the Build server, this is the most important step otherwise you application will not build successfully in the team build you may faces some errors like :
error CS0234: The type or namespace name 'Mvc' does not exist in the namespace 'System.Web' (are you missing an assembly reference?)
or
Controllers\RuleController.cs(31,10): error CS0246: The type or namespace name 'AcceptVerbs' could not be found (are you missing a using directive or an assembly reference?)
** Update
This will work with Beta version of ASP.NET MVC since the installation register the MVC assembly in GAC.
For preview versions , you can reference the DLL from your build project
<AdditionalReferencePath Include="C:\Program Files\Microsoft ASP.NET\ASP.NET MVC CodePlex Preview 4\Assemblies" />
Thanks !
Pingback from ASP.NET MVC Archived Blog Posts, Page 1 | http://weblogs.asp.net/hosamkamel/archive/2008/11/20/asp-net-mvc-project-and-team-build-issue.aspx | crawl-002 | en | refinedweb |
Adventures in .NET
Assembly Cannot Be FoundThis causes the following error message:The assembly <assemblyname> could not be found at <path> or could not be loaded.You can still edit and save the document. Contact your administrator or the author of this document for further assistance.
I did some digging around on Microsoft's VSTO Troubleshooting Page , and found this:
Class=<namespace>.<classname>
<Assembly: System.ComponentModel.DescriptionAttribute( "OfficeStartupClass, Version=1.0, Class=<namespace>.<classname>")>
For information on changing the assembly path manually, see How to: Link an Assembly to a Word or Excel File. For a code example that changes the property from relative to absolute, see Code: Change the Assembly Path from Relative to Absolute in a Document (Visual Basic), or Code: Change the Assembly Path from Relative to Absolute in a Document (C#).
For information on the custom properties, see Word and Excel Project Properties.
Allow me to add to this list one more problem that can cause this error: the target machine does not have the Office 2003 PIA's installed. This is not documented anywhere that I can find, so I post it here.
Cheers!
I have created an excel file with the appropriate assembly which works fine if the assembly is located anywhere on my PC but not if the assembly is on a network with the excel file located locally. I have gone through everything I can think of, including all the solutions you have listed, but I still get the same error. Any ideas????
1) The permission set for an assembly must be set up under Machine->All Code->LocalIntranet_Zone.
2) The _AssemblyLocation0 Document property must be give the fully qualified network path to the Assembly.
You Should be able to run caspol.exe -rsg <Full path to Assembly> and see if there is some other permission set that is keeping the code from executing.
Caspol.exe is located at <system>\Microsoft.NET\Framework\v1.1.4322.
If this doesn't work, reply to this comment with more details about your project.
I am having a similar problem with a WORD template, and have addressed both the assembly name and the caspol issues. Still I get the error. Any other ideas?
Thanks in advance. | http://weblogs.asp.net/taganov/archive/2004/09/24/233847.aspx | crawl-002 | en | refinedweb |
ASP.NET v2.0 has a couple new ways to reference connection strings stored in the web.config or machine.config file.
A typical web.config file in v2.0 could have the following section which is placed directly under the root <configuration> section.
<connectionStrings> <remove name="LocalSqlServer" /> <add name="LocalSqlServer" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true" providerName="System.Data.SqlClient"/> <add name="MainConnStr" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|main.mdf;User Instance=true" providerName="System.Data.SqlClient"/></connectionStrings>
You can reference this directly from code using:
[C#]string connStr = ConfigurationManager.ConnectionStrings["MainConnStr"].ConnectionString;
[VB]Dim connStr As String = ConfigurationManager.ConnectionStrings("MainConnStr").ConnectionString
Note that the namespace for this is System.Configuration so for a console application the full namespace is required.
Or you can reference this declaratively within the ConnectionString property of a SqlDataSource:
<asp:SqlDataSource
Hello,
The connection strings you are discussing about actually connects to MSSQL 2005. I am using similar connection string for my application:
>
But unfortunately, my server doesn't support 2005 and asks me to use 2000. Can you help me out with changes I should be making in order to make it work with 2000 as well please?
I would be waiting for your replay. You can email me at: munjalpatel@ieee.org
Thanks :)
That's not the first time this blog helps me. If you had had adsense you could have some cents in your account.
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What if my database is stored in the directory above App_Data?
Don't ask me why, it really isnt, but I would like to know.
I've created a datagrid on a web page using vb.net. The web config file that is configured in visual studio works when I run the page works locally, but when I run the web page from our server I get a configuration error. It seems to be looking at a web.config file in another location of our server than the web site folder.
If I change the web config file to:
<configuration>
<appSettings>
</appSettings>
<connectionStrings>
<add name="ConnectionString" connectionString="data source=IP,Port; initial catalog=db; user id=username; password=password;"/>
</connectionStrings>
<system.web>
<customErrors mode="Off"/>
<compilation debug="true"/>
</system.web>
</configuration>
It works fine. I would like to have the flexibility to refer to the connection string in the code, and I'm also curious what is going on.
FYI, I'm a beginner. Hope I provided enough info.
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i want to know the same connection string when using a access database file and should have the path from the localhost
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Dear Ms/Sir
Hi.
We have a VPS software with its modules. I installed the VPS and configured it, it works properly without any problem.
But I couldn't install and configure the web based modules and features. I know that they need to be expert on ASP and IIS.
I would like to kindly ask you to help me in installation, configuration and setting up the web based features and modules please.
It is very important and urgent for us.
If there is any documents for the configuration and setting up the VPS and its Modules, May I kindly ask you to send them to me please.
I am very interested to learning the installation and configuration of VPS and its modules. Could you Please help me.
Thanks a lot for your attention.
Regards,
Daniel.
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I want to know how to connect sql express database using asp.net 2.0 by passing connection string in <appSettings> section of web.config file.
Thanks & Regards,
Andy | http://weblogs.asp.net/owscott/archive/2005/08/26/Using-connection-strings-from-web.config-in-ASP.NET-v2.0.aspx | crawl-002 | en | refinedweb |
.security.deploy;18 19 /**20 * @version $Rev: 476049 $ $Date: 2006-11-16 23:35:17 -0500 (Thu, 16 Nov 2006) $21 */22 public class DefaultRealmPrincipal extends DefaultDomainPrincipal {23 private String realm;24 25 public String getRealm() {26 return realm;27 }28 29 public void setRealm(String realm) {30 this.realm = realm;31 }32 }33
Java API By Example, From Geeks To Geeks. | Our Blog | Conditions of Use | About Us_ | | http://kickjava.com/src/org/apache/geronimo/security/deploy/DefaultRealmPrincipal.java.htm | CC-MAIN-2017-30 | en | refinedweb |
Hi,
>>> classes may explain HOW they work, but it's unclear for me which one is
>>> the most appropriate one to use.
>>>
>
> See
>
>
Thanks Thomas. I saw this, too. But when browsing all the information on
the Wiki, I really get confused about which information is up-to-date,
if there is any. A problem a lot of open source projects suffer from, I
guess.
Alexander said he thinks a FileSystem is not used, in conjunction with a
SimpleDB PM (my configuration at the moment), so it would be save to
just switch to a local filesystem implementation. He pointed me to [1],
which says FileSystem is only used by some parts of Jackrabbit.
I checked the database and I see entries in the globally shared
filesystem (records for /meta/rootUUID, /meta/rep.properties,
/namespaces/ns_reg.properties, /namespaces/ns_idx.properties and
/nodetypes/custom_nodetypes.xml).
The persistence manager FAQ [2] says BundlePMs are usually the fastest,
and are used in conjunction with either a LocalFileSystem or a
DbFileSystem, so according to this it seems a FileSystem is still needed.
The clustering documentation [3] states each cluster node needs its own
(private) FileSystem and all nodes must store their data in the same
globally accessible location.
When I have one cluster node with a repository which already has some
data, and I add a new node to the cluster with a different DbFileSystem,
after the new node has updated its state and is in sync with the
repository, when accessing the repository through the new node I get an
exception the node does not know my custom namespace configuration. When
using the same DbFileSystem configuration for all nodes, I don't get
this exception and all seems to work well... But it doesn't feel right,
because I don't know what the effects might be. If I would use a
database-bundle-PM in a cluster setup, do I need a shared (Db)FileSystem
or would it be better to use a local filesystem and do I have to
configure my custom nodetypes on every cluster node separately?
Thanks,
Dennis
--
Dennis van der Laan | http://mail-archives.apache.org/mod_mbox/jackrabbit-users/200912.mbox/%3C4B260256.5020509@rug.nl%3E | CC-MAIN-2017-30 | en | refinedweb |
iParticleEffector Struct Reference
[Mesh plugins]
Base interface for particle effector. More...
#include <imesh/particles.h>
Inheritance diagram for iParticleEffector:
Detailed Description
Base.4.1 by doxygen 1.7.1 | http://www.crystalspace3d.org/docs/online/api-1.4.1/structiParticleEffector.html | CC-MAIN-2017-30 | en | refinedweb |
On Tue, Mar 1, 2011 at 7:10 PM, Sean Carolan <scarolan at gmail.com> wrote: > On Tue, Mar 1, 2011 at 11:55 AM, Sean Carolan <scarolan at gmail.com> wrote: >> Maybe someone can help with this. I have a function that takes a >> single file as an argument and outputs a tuple with each line of the >> file as a string element. This is part of a script that is intended >> to concatenate lines in files, and output them to a different file. > > Not sure if this is the "right" or best way to do this, but I ended up > using vars() to assign my variable names, like so: > > import sys > > myfiles = tuple(sys.argv[1:]) > numfiles = len(myfiles) > varlist = [] > > def makeTuple(file): > 6 lines: outlist = [] ---------- > > for i in range(numfiles): > varlist.append('tuple'+str(i)) > vars()[varlist[i]] = makeTuple(myfiles[i]) As you can see in the documentation, you really shouldn't modify the object returned by vars() or locals(). It might work in some cases for some implementations of python, but it's actually an undefined operation, which basically means that an implementation may do anything it damn well pleases when you try to actually do it. Really, you shouldn't be trying to dynamically add variables to the namespace for each tuple, it's dangerous and can introduce all sorts of hard-to-catch bugs. Instead, put all your tuples in a list, and address them by index: tuples = [] for file in myfiles: tuples.append(makeTuple(file)) now you can address your tuples by tuples[0], tuples[1] and so forth, which is pretty much the same as tuple0, tuple1, etc. Even better, since it's in a list we can also iterate over it now with a for loop, isn't that great? Note also how I'm iterating over the myfiles list, which means I don't have to use the range() function together with indexing with i, which is a lot more readable. HTH, Hugo PS: There's even shorter ways to write this little script, but I won't bother you with them. If you want to know, check the map function, and list comprehensions. | https://mail.python.org/pipermail/tutor/2011-March/082297.html | CC-MAIN-2017-30 | en | refinedweb |
Hi Jodok > Cc: Christian Zagrodnick; zope3-dev@zope.org > Betreff: Re: [Zope3-dev] Re: skin support for xmlrpc
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[...] > for me xmlrpc is remote procedure call. a rpc has a signature > and always the same result. and as stephan said - traversers > should help here. Yes, but what does this mean? Where is the difference to any other view e.g. BrowserRequest views. XML-RPC views are exactly the same as any other multi adapter which can get traversed. All of them need to support a layer. Except that the default layer for XML-RPC is the XMLRPC request and not the DefaultBrowserRequest. Traverser are not needed for this. That's a totaly different concept. btw, the layer is a namespace for permission settings and not skinning/layout in this usecase. [...] Regards Roger Ineichen _____________________________ END OF MESSAGE _______________________________________________ Zope3-dev mailing list Zope3-dev@zope.org Unsub: | https://www.mail-archive.com/zope3-dev@zope.org/msg09287.html | CC-MAIN-2017-30 | en | refinedweb |
This should not make a big difference in real world since libvirt-daemon, which is already required by libvirt-lock-sanlock, requires libvirt-client and thus libvirt-lock-sanlock gets this dependency transitively. However, since libvirt-lock-sanlock contains sanlock_helper binary linked to libvirt.so, we should start requiring libvirt-client directly. --- libvirt.spec.in | 1 + 1 file changed, 1 insertion(+) diff --git a/libvirt.spec.in b/libvirt.spec.in index 2f3e829..511949e 100644 --- a/libvirt.spec.in +++ b/libvirt.spec.in @@ -1029,24 +1029,25 @@ Include header files & development libraries for the libvirt C library. %if %{with_sanlock} } +Requires: %{name}-client = %{version}-%{release} %description lock-sanlock Includes the Sanlock lock manager plugin for the QEMU driver %endif %if %{with_python} %package python Summary: Python bindings for the libvirt library Group: Development/Libraries Requires: %{name}-client = %{version}-%{release} -- 1.7.12.3 | https://www.redhat.com/archives/libvir-list/2012-October/msg00971.html | CC-MAIN-2017-30 | en | refinedweb |
CSS to style HTML.
The
reset.css file is used in the GWT module project configuration to create a common
CSS playing field for GXT across all supported browsers. So, when styling HTML you will
have to provide some of the default styles explicitly.
There is more than one option to providing style to widgets and elements starting with
UiBinder and
ClientBundle below. When you provide your own style, be sure to check
the target browsers for rendering consistency.
UiBinder provides an inline style element to add the CSS selectors. This adds the style inline which will affect the entire application.
Example UiBinder with an inline style configuration.
<ui:UiBinder xmlns: <!-- - can be used to copy default styles --> <ui:style> h1 { font-size: 2em; margin: .67em 0; } </ui:style> <g:HTMLPanel> <h1>This is heading 1</h1> </g:HTMLPanel> </ui:UiBinder>
GWT provides handy resource bundling which allows for clean abstraction of styles. This method shows how you could use raw HTML in a widget and style it.
There are three steps to wiring up a client bundle.
Configure the CSS file.
Configure the Java interface to reference the CSS selectors and other resources.
Inject the styles then get and set the style name on the widget or element.
customStyles.css file which will provide the style through the client bundle.
/* customStyles.css file */ .htmlFormatting { border: 1px solid red; } .htmlFormatting h1,h2,h3,h4,h5,h6 { border: 2px solid blue; }
This wires up the client bundle for CSS resources access in the widget.
import com.google.gwt.core.client.GWT; import com.google.gwt.resources.client.ClientBundle; import com.google.gwt.resources.client.CssResource; public interface CustomHtmlStyle extends ClientBundle { // static factory for getting the client bundle resource instance public static final CustomHtmlStyle INSTANCE = GWT.create(CustomHtmlStyle.class); public interface LayoutStyles extends CssResource { // this is one of the css selectors in the style sheet String htmlFormatting(); } // the css file name 'customStyles.css' located in the same package public LayoutStyles customStyles(); }
Example using the client bundle instance to get the CSS selector style name.
import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.IsWidget; import com.google.gwt.user.client.ui.Widget; import com.sencha.gxt.widget.core.client.container.CssFloatLayoutContainer; import com.sencha.gxt.widget.core.client.container.CssFloatLayoutContainer.CssFloatData; public class HtmlStyle implements IsWidget { private CssFloatLayoutContainer widget; @Override public Widget asWidget() { if (widget == null) { // inject the styles into the document so they are available CustomHtmlStyle.INSTANCE.customStyles().ensureInjected(); widget = new CssFloatLayoutContainer(); widget.add(new HTML("<h1>This is heading 1</h>"), new CssFloatData(1)); // Get the client bundle style name reference String styleName = CustomHtmlStyle.INSTANCE.customStyles().htmlFormatting(); widget.setStyleName(styleName); } return widget; } } | http://docs.sencha.com/gxt/3.x/guides/ui/style/HtmlStyle.html | CC-MAIN-2017-30 | en | refinedweb |
Sort::ArbBiLex - make sort functions for arbitrary sort orders" }
Writing systems for different languages usually have specific sort orders for the glyphs (characters, or clusters of characters) that each writing system uses. For well-known national languages, these different sort orders (or someone's (what's I'll e's). there can't doesn't assume that the units of comparison are necessarily individual characters.
* The most notable limitation of this module is that its identification of glyphs must be context-insensitive. So you can't stipulate that, for example, ":" normally counts as a letter after "h", but that it doesn't count (or that it counts as a letter after "z", or whatever) in the special case of appearing at the start of words.
* You can't declare whitespace characters of any kind as sortable glyphs using the single-string ("short form") declaration. This is, obviously, because in that declaration format, whitespace is reserved as the delimiter for glyphs and families. So if you want to have space, tab, CR, and/or LF be sortable glyphs, you just have to declare that with the long form (LoL-reference) format. See the sections on these formats, below.
* When you have Sort::ArbBiLex generate a new bi-level sort function based on a sort-order declaration, both levels of comparison obviously have the same sort-order declaration -- so you can't have Sort::ArbBiLex make a function where at one level "ch" counts as one glyph, and at the other, it counts as two; nor where it counts as a glyph in one position in one level, and at another position in the other level.
* When you declare a glyph as consisting of several characters, you're saying that several letters should be considered as one unit. However, you can't go the other way: you can't say that a single letter should be considered as a combination of glyphs. But I've seen some descriptions of German sort order that say that a-umlaut (etc) should be treated as if it were a literal "ae" -- i.e. an "a" glyph followed by an "e" glyph. This can't be done simply with Sort::ArbBiLex.
* Note that ArbBiLex-generated sort routines always start sorting (at both levels) with glyphs at the start of the string, and continue to the end. But some descriptions (like p138 of the Unicode Standard Version 3.0) of French sort order say that the the first level of sorting goes as you'd expect, start to finish, but a later level, ties between different accents are broken starting from the end, and working backwards. This can't be done simply with Sort::ArbBiLex. (But it's my experience that the difference is not significant, in the case of French data.)
* If you're using a pre-Unicode version of Perl: you cannot declare more than 255 glyph-groups (i.e., glyphs that sort the same at the first level), and no glyph-group can contain more that 255 glyphs each. However, it's fine if the total number of glyphs in all glyph-groups sums to greater than 255 (as in the case of a declaration for 30 glyph-groups with 10 glyphs each).
* This library makes no provision for overriding the builtin
sort function. It's probably a bad idea to try to do so, anyway.
* If all of the glyphs in a given sort order are one character long, the resulting sorter function will be rather fast. If any of them are longer than that, it is rather slower. (This is because one-character mode does its work with lots of
tr///'s, whereas "multi"-character mode (i.e., if any glyphs are more than one character long) uses lots of
s///'s and hashes. It's as fast as I can make it, but it's still necessarily much slower than single-character mode. So if you're sorting 10,000 dictionary headwords, and you change your sort order from one that uses all one-character glyphs, to one where there's even just one two-character glyph, and you notice that it now takes 15 seconds instead of 3 before, now you know why.
* Remember, if this module produces a function that almost does what you want, but doesn't exactly, because of the above limitations, then you can be have it output the source (via
source_maker) of the function, and try modifying that function on your own.
This module provides two main functions,
Sort::ArbBiLex::maker and
Sort::ArbBiLex::source_maker, and it also presents an interface that accepts parameters in the
use Sort::ArbBiLex ( ... ) statement.
use Sort::ArbBiLex;
This merely loads the module at compile-time, just like any normal "use [modulename]". But with parameters, it's special:
use Sort::ArbBiLex ( 'name', DECLARATION, ... );
This compile-time directive, besides loading the module if it's not already in memory, will interpret the parameters as a list of pairs, where each pair is first the name of a sub to create and then the DECLARATION of its sort order. This calls
Sort::ArbBiLex::maker(DECLARATION) to make a such-named function, that sorts according to the sort order you specify.
This is probably the only way most users will need to interact with this module; they probably won't need to call
Sort::ArbBiLex::maker(DECLARATION) (much less
Sort::ArbBiLex::source_maker(DECLARATION)!) directly.
Unless your sort-order declarations are variables, you can simply use this
use Sort::ArbBiLex (...) syntax. Feel free to skip ahead to the "Values for DECLARATION" section.
maker is called thus:
Sort::ArbBiLex::maker(DECLARATION)
This will make a sort function, based on the contents of DECLARATION. The return value is an anonymous subroutine reference. While you can store this just like any another anonymous subroutine reference, you probably want to associate it with name, like most functions. To associate it with the symbol
fulani_sort in the current package, do this:
*fulani_sort = Sort::ArbBiLex::maker($my_decl);
Then you can call
fulani_sort(@whatever) just like any other kind of function, just as if you'd defined
fulani_sort via:
sub fulani_sort { ...blah blah blah... }
As you might expect, you can specify a package, like so:
*MySorts::fulani_sort = Sort::ArbBiLex::maker($my_decl);
If you don't know what
*thing = EXPR means or how it works, don't worry, just use it -- or duck the whole issue by using the "
use Sort::ArbBiLex ('fulani_sort', DECL);".
Actually, there's a minor difference between the various ways of declaring the subroutine
fulani_sort: if you declare it via a call to this:
*fulani_sort = Sort::ArbBiLex::maker($my_decl);
then that happens at runtime, not compile time. However, compile-time is when Perl wants to know what subs will exist if you want to be able to call them without parens. I.e., this:
@stuff = fulani_sort @whatever; # no parens!
will cause all sorts of angry error messages, which you can happily avoid by simply adding a "forward declaration" at some early point in the program, to express that you're goung to want to use "fulani_sort" as a sub name:
sub fulani_sort; # yup, just that! ...later... *fulani_sort = Sort::ArbBiLex::maker($my_decl); ...later... @stuff = fulani_sort @whatever; # no parens!
And then all should be well.
The short story is to use the "
use Sort::ArbBiLex ('fulani_sort', ...)" syntax whenever possible (at which point you're free to omit parens, since the "use" makes it happen at compile-time, not runtime).
But when you can't use the "
use Sort::ArbBiLex ('fulani_sort', ...)" syntax, and you need to use a "
*foo = ..." syntax instead (which is usually necessary if your declaration is a variable, instead of a literal), then either add a "
sub fulani_sort;" line to your program; or just be sure to use parens on every call to the
fulani_sort function.
See also: perlsub, for the whys and wherefors of function protoptying, if you want all the scary details.
Sort::ArbBiLex::source_maker is just like
Sort::ArbBiLex::maker, except that it returns a string containing the source of the function. It's here if you want to, well, look at the source of the function, or write it to a file and modify it.
DECLARATION is a specification of the sort order you want the new function to sort according to.
It can occur in two formats: short form (a single string), and long form (a reference to a list of lists of glyphs).
A short-form specification consists of a string that consists of lines containing glyphs. The example in the SYNOPSIS section shows this format.
Formally, lines in the short-form declaration string are separated by carriage returns and/or linefeeds. Each line consists of glyphs separated by whitespace (other than CRs or LFs). Lines that are empty (i.e., which contain no glyphs) are ignored. A declaration that contains no glyphs at all is illegal, and causes a fatal error. A "glyph" is any sequence of non-whitespace characters. No glyph can appear more that once in the declaration, or it's a fatal error.
A degenerate case of there being only one glyph-family with many glyphs in it (i.e., a one-level sort instead of a bi-level), like this:
Sort::ArbBiLex::maker('fulani_sort', "a A c C c' C' e E h H x X i I : l L n N r R s S u U z Z zh Zh ZH" );
is actually treated as if it were that many glyph-families with only one glyph in each. This in an internal optimization.
PLEASE NOTE that any characters that are in the data being sorted but which do not appear in the sort order declaration (neither as themselves, or as part of glyphs) are treated as if they are not there. In other words, given the sort order in the above example, if you had "David" as an item to sort, it would sort just as if it were "ai" -- since "D", "v", and "d" aren't in that declaration. So think twice before deciding that certain letters "are not part of the alphabet" of the language in question.
Note also that if, say, "ch" is in the sort order, but "h" isn't, then an "h" not after a "c" (like in "helicopter" or "pushed") will not be counted for sake of sorting.
A long-form specification consists of a reference to a list of lists of glyphs. For example, the example from the SYNOPSIS section could just as well be denoted with a long-form declaration like this:
use Sort::ArbBiLex ( 'fulani_sort', [ [ "a", "A" ], [ "c", "C" ], [ "ch", "Ch", "CH" ], [ "ch'", "Ch'", "CH'" ], [ "e", "E" ], [ "l", "L" ], [ "lh", "Lh", "LH" ], [ "n", "N" ], [ "r", "R" ], [ "s", "S" ], [ "u", "U" ], [ "z", "Z" ], ] );
The main practical reason I provide this declaration is that, as discussed in the Limitations section, the short form doesn't allow you to declare whitespace characters of any kind as sortable glyphs using the single-string ("short form") declaration, because in that declaration format, whitespace is reserved as the delimiter for glyphs and families. But you can do it in the long form. In the above example, you'd just add a line before the one for a/A, like this:
use Sort::ArbBiLex ( 'fulani_sort', [ [ " ", "\t", "\cm", "\cj" ], # whitespace characters. [ "a", "A" ], ...etc...
That'd make whitespace the first glyph family. The effect of this would be to make sorting sensitive to whitespace, such that "for", "for sure", and "forest" would sort in that order. It's my impression that most modern English dictionaries sort without respect to whitespace (so that that list, sorted, would be "for", "forest", "for sure"), but I also realize that that's not the only way to do it. In fact, sensitivity to whitespace seems an inevitable part of conventional sort orders for some languages.
A thought: Presumably the only place you'd want to put the whitespace family is at the start of the declaration. It'd be really strange in the middle or the end, I think.
A word of caution: Note that, if you have whitespace as a glyph family, "for sure" (with just the one space) and "for sure" (with two spaces inbetween) do not sort the same. You may expect that the sorter would magically collapse whitespace, seeing all sequences of whitespace as equal. Au contraire! They're glyphs, just like any others, so sorting "for sure" and "for sure" (two spaces) is totally analogous to sorting "ika" and "ikka".
For most purposes, a sorter function generated by Sort::ArbBiLex is all you need. However, in some cases, you need the equivalent of a language-specific
cmp function. For example, consider this construct:
@records = sort { $a->{'headword'} cmp $b->{'headword'} } @records;
If you think want a language-specific
cmp, you can work around it by start with a ArbBiLex-made function called
my_sort, and having:
{ my %hw2rec; # temporary mapping from headwords to records for(@records) { push @{$hw2rec{ $_->{'headword'} }}, $_ } @records = map @{$hw2rec{$_}}, my_sort( keys %hw2rec ); }
and that's fine, and probably more time-efficient than what I'm about to suggest.
If you really insist on having functions that act like
cmp and the other Perl comparator functions (
lt,
gt,
le,
ge), you can use these meta-functions:
Sort::ArbBiLex::xcmp(\&my_sort, $a,$b) Sort::ArbBiLex::xlt( \&my_sort, $a,$b) Sort::ArbBiLex::xgt( \&my_sort, $a,$b) Sort::ArbBiLex::xle( \&my_sort, $a,$b) Sort::ArbBiLex::xge( \&my_sort, $a,$b)
Incidentally, these all work by seeing what the
my_sort function (i.e., whatever you pass a reference to) does when asked to sort the two values you pass. Ideally, language-specific comparators would instead have been implemented by generating new comparator functions based on sort-order declarations, i.e., the same way we get sort functions. However, comparators are needed rarely enough, and in already inefficient enough settings, that I sacrifice comparators' efficiency for the sake of the clarity of the module.
So a concise way to say this
@records = sort { $a->{'headword'} cmp $b->{'headword'} } @records;
with language-specific sorting is:
@records = sort { Sort::ArbBiLex::xcmp(\&my_sort, $a->{'headword'}, $b->{'headword'}) } @records;
If you'd be doing that a lot, you can even wrap that comparator in a new function:
sub my_cmp { Sort::ArbBiLex::xcmp(\&my_sort, @_) };
The full repertory of these would be:
use Sort::ArbBiLex ('my_sort' => ...whatever...); sub my_cmp { Sort::ArbBiLex::xcmp(\&my_sort, @_) }; sub my_lt { Sort::ArbBiLex::xlt( \&my_sort, @_) }; sub my_gt { Sort::ArbBiLex::xgt( \&my_sort, @_) }; sub my_le { Sort::ArbBiLex::xle( \&my_sort, @_) }; sub my_ge { Sort::ArbBiLex::xge( \&my_sort, @_) };
Using these functions makes for very readable code, like so:
@records = sort { my_cmp($a->{'headword'}, $b->{'headword'})} @records;
but this will be almost definitely be much less time-efficient, for large lists, than the workaround mentioned at the top of this section. Benchmark both ways if you really need to know which is faster for your data set. If neither are as fast as you really need them to be, then use
sort_maker to generate source code for a given declaration, and fiddle with that code to make comparators; the result should be much faster, even though it may take you a bit of doing. As always, though, don't try optimizing unless you're sure you need to (and don't be surprised if it doesn't have as great an effect as you hoped for).
Here's a declaration for a sort function that uses all the characters A-Z / a-z and also all the alphabetic characters in Latin-1. It should be a a good starting point for most declarations you'd want:
use Sort::ArbBiLex ( 'schmancy " );
Edit and re-shuffle letters as necessary.
* ArbBiLex stands for "arbitrary bi-level lexicographic".
* The source to this module may tie your brain in knots. That's what it does to me, and I wrote it. Code that writes code can be icky that way.
If you want to figure out this module's workings, try using:
print Sort::ArbBiLex::source_maker($decl);
where you start out with $decl as something short. Understand the code that this module makes before you try to understand how it makes it.
* The sorter functions this module makes are built around the Schwartzian transform -- i.e., the construct "map BLOCK sort BLOCK map BLOCK List". For a brief discussion of that, see perlfaq4, under the question "How do I sort an array by (anything)?". Or maybe I'll write a Perl Journal () article about it some time.
* If you look at, say,
use Sort::ArbBiLex (fu => "a b c ch d i h s sh x"); @x = fu( qw(chachi baba) );
and if you wonder how the "ch" in "chachi" ends up as one glyph "ch" (which is what happens), instead of as a glyph "c" and a glyph "h" (which is not what happens), then consider that this
print "<$1>" while 'chache' =~ /(ch|c|h|a|e)/g
prints "<ch><a><ch><e>", not "<c><h><a><c><h><e>".
* While you're at it, consider that this:
print "<$1>" while "itlha" =~ /(tl|lh|l|h|i|a)/g
prints "<i><tl><h><a>", never "<i><t><lh><a>". Presumably this is always The Right Thing.
* Most modules that define an
import method (either directly, or by inheritating from the Exporter module), use it to just export pre-existing subs from their own package into the calling package. But Sort::ArbBiLex's
import is different -- there's no pre-existing subs to export, so it just makes new anonymous subs on demand, and sticks them into the package that's current for the given "
use Sort::ArbBiLex" line (unless the given subname already has a package name on it, like "MySorts::nornish"). | http://search.cpan.org/~sburke/Sort-ArbBiLex-4.01/ArbBiLex.pm | CC-MAIN-2017-30 | en | refinedweb |
We commonly come across a problem where we need to write a unit test case of an existing application and found that it has tons on dependency of static methods.
Here we would be directly jumping on how to refactor your code to get rid of static methods meanwhile you can go through the following blogs to understand why static methods hinder testability
So here we go, we have a problem statement where we have a static class which is being used by another class
public class Utility { public static void PerformTask() { // your code } } public class TestClass { public void TestMethod() { // Initial piece of code Utility. PerformTask(); // Rest of your code } }
We are going to solve this problem in 3 steps.
1st Step: Create interfaces having logical segregation of task being performed by the Utility class, for us, we have just one method so one interface would be sufficient.
public interface IUtility { void PerformTask(); }
2nd Step: Create a concrete class for each interface created in step 1 and have the desired implementation, there which was initially done in your static methods.
public class Utility : IUtility { public void PerformTask() { // your code } }
3rd Step: Inject the correct Interface in your desired class where you were calling the static methods.
public class TestClass { private IUtility utility; public Client(IUtility utility) { this.utility = utility; } public void TestMethod() { // Initial piece of code utility. PerformTask(); // Rest of your code } }
Aha, we are done now. You are free to resolve your interfaces with desired class instance and create mock for its testing and yes, you are free to you any DI framework. | http://dailydotnettips.com/2015/03/10/how-to-refactor-and-make-static-class-code-testable/ | CC-MAIN-2017-30 | en | refinedweb |
Posted at: 11:23 PM on 26 May 2010 by Nycklander
Hi, I’m Nicolas and today I will show how to merge multiple PDF files using a SharePoint Designer workflow using the PDF Converter for SharePoint and the Workflow Power Pack.
Update: Please note that as of version 5.0 of the PDF Converter it is also possible to merge PDF Files using the SharePoint User Interface as well as via direct Web Service calls. shows how to create a SharePoint Designer workflow and attach it to a document library. This workflow is triggered when adding or modifying an item in the library, for example after converting a document using the PDF Converter. This example is particularly useful when you want to automatically add a cover page or Appendix to each and every PDF file in the system.
The workflow checks if the file extension for the current item is “pdf”. If this is the case then it uses the Workflow Power Pack to execute some C# code that carries out the actual appending of PDF files. The solution provided in this post works in SharePoint 2007 as well as 2010.
Create the workflow as follows:
- Download and install the Muhimbi Workflow Power Pack for SharePoint
- Download and install the Muhimbi PDF Converter for SharePoint
- We need to be able to access functionality in the Muhimbi.SharePoint.DocumentConverter.PDF the Shared Documents library, tick the boxes next to both “Automatically.
c. Click on the second value and enter pdf. (Use lower case as the compare option is case sensitive).
- Click the Actions button and insert the Execute Custom Code action.
- Click parameter 1 and enter a relative or absolute path to the PDF file you want to append to the current workflow item. For example /sites/PDFConversion/Shared%20Documents/appendix.pdf or Shared%20Documents/appendix.pdf
- Optionally, click parameter 2 to specify a second PDF file to append.
- Insert the C# based code listed below by clicking this code in the workflow designer. Note that copying this code using Internet Explorer may remove line breaks. Preferably use Chrome or Firefox to copy the code or alternatively paste it from Internet Explorer into Windows Wordpad and then copy it from there into SharePoint Designer.
/*********************************************************************************************
Muhimbi PDF Converter - Combining Multiple PDF Files
The following code shows a simple way to merge PDF content from one or more files.
Error and permission checking as well as other minor features have been omitted for the sake
of brevity and clarity.
This code requires Muhimbi’s PDF Converter and Workflow Power Pack to be installed.
**********************************************************************************************/
using Syncfusion.Pdf.Parsing;
using System.IO;
// ** Some variables we're going to use
SPFile spDocument1ToAppend = null;
SPFile spDocument2ToAppend = null;
PdfLoadedDocument document1ToAppend = null;
PdfLoadedDocument document2ToAppend = null;
// ** Get and load current pdf document (the one which triggered the workflow)
SPFile spSourceDocument = MyWorkflow.Item.File;
PdfLoadedDocument sourcePdfDocument = new PdfLoadedDocument(spSourceDocument.OpenBinary());
// ** If supplied, get and load 1st pdf document to append to
string document1ToAppendPath = MyWorkflow.Parameter1 as string;
if (!string.IsNullOrEmpty(document1ToAppendPath))
{
spDocument1ToAppend = MyWorkflow.Web.GetFile(document1ToAppendPath);
document1ToAppend = new PdfLoadedDocument(spDocument1ToAppend.OpenBinary());
}
// ** If supplied, get and load 2nd pdf document to append to
string document2ToAppendPath = MyWorkflow.Parameter2 as string;
if (!string.IsNullOrEmpty(document2ToAppendPath))
{
spDocument2ToAppend = MyWorkflow.Web.GetFile(document2ToAppendPath);
document2ToAppend = new PdfLoadedDocument(spDocument2ToAppend.OpenBinary());
}
// ** Get destination file and folder
string destinationFolderUrl = spSourceDocument.ParentFolder.Url;
SPFolder spDestinationFolder = MyWorkflow.Web.GetFolder(destinationFolderUrl);
string destinationFileName = spSourceDocument.Name;
string destinationFilePath = string.Format("{0}/{1}", destinationFolderUrl, destinationFileName);
SPWeb spDestinationWeb = spDestinationFolder.ParentWeb;
SPFile spDestinationFile = spDestination mergedDocument = new MemoryStream())
{
// ** Append files to destination document
if (document1ToAppend != null)
sourcePdfDocument.Append(document1ToAppend);
if (document2ToAppend != null)
sourcePdfDocument.Append(document2ToAppend);
// ** Save merged file and overwrite in document library
sourcePdfDocument.Save(mergedDocument);
spDestinationFile = spDestinationWeb.Files.Add(destinationFilePath, mergedDocument, spSourceDocument.Item.Properties, true);
}
// ** Check the file back in if this script was responsible for checking it out
if (spDestinationFile.Item.ParentList.ForceCheckout)
spDestinationFile.CheckIn("Auto check-in after PDF document appending.");
- Click the Actions button, select Log to History List, click this message and enter PDF content appended to current item.
- Close the Workflow Designer.
- Update an existing PDF or add a new PDF file to your document library to trigger the workflow and append contents from the files defined in parameter 1 and parameter 2.
- The workflow should look something like this.
Of course this is just a sample, feel free to play around with the code, change which parameters are passed into the workflow, use different document libraries as source and destination of PDF documents, change the sequence in which documents are appended, etc.
Please leave a comment if you’re trying to do anything specific or if you want to share your experience with this approach.
As always, feel free to contact us using Twitter, our Blog, regular email or subscribe to our newsletter.
.
Labels: Articles, pdf, PDF Converter, Products, SP2010, Workflow, WPP
4 Comments:
Hey great article! Will I be able to use this to convert infopath forms into PDF files?
By
AKhan, At
30 July, 2010 20:09
Hi Akhan,
Absolutely, many of our customers use our tools to convert InfoPath to PDF.
You can either do it from SharePoint () or from any Web Services based platform ()
Contact support@Muhimbi.com if you have any questions.
By
Muhimbi, At
30 July, 2010 22:23
I am attempting to get code that worked in previous sharepoint version and muhimbi version, to the latest of both, but the validate fails every time now when I add a lookup field. I use the dynamic lookup fields to populate a batch file, that is then passed on to custom code. I am unsure what to do to fix it, the code runs fine without the lookup, but when I include it, then it will not save. Please help.
By
Tom, At
01 November, 2010 20:24
Hi Tom,
Perhaps best if you contact the support desk using the 'Contact Us' link at the top of the page. Please include details about the version of the software you used to run, what version you upgraded to and what it is exactly that you are trying to do. The more information the better, including messages from the Windows Application event log.
By
Muhimbi, At
01 November, 2010 22:03
Links to this post:
Create a Link | http://blog.muhimbi.com/2010/05/combining-multiple-pdf-files-using.html | CC-MAIN-2017-30 | en | refinedweb |
In the last installment in this series, we talked about code coverage, what they are, and how you should use them. I gave examples in both Haskell and F# to accomplish this goal. One thing we’ve touched briefly in this conversation is around refactoring and cleaning up our code, and it’s about time we come back to that subject.
But, before we continue, let’s get caught up to where we are today:
- Part 1 – xUnit Frameworks – HUnit
- Part 2 – Property-Based Tests – QuickCheck
- Part 3 – QuickCheck + xUnit Tests Together
- Part 4 – Code Coverage
Refactoring
I want to revisit our topic of refactoring that I talked about with my foray into testing with HUnit. In this post and the next couple of posts, I want to explore three different areas with refactoring including the following:
- Keeping Things Pure
- Monadic Isolation for Testing
- Refactoring with frameworks (HLint, etc)
In this post, let’s cover keeping things pure and separating the side effecting code from our pure code.
Keeping Things Pure
Let’s take a simple example of obtaining three odd numbers from a given stream handle. Because side effects in Haskell are explicit, we have to be mindful of how we get our input. This affects the signature of our function as it is no longer returning an integer list, but instead an IO integer list. As I’ve stated in previous posts, you use QuickCheck for your pure code and xUnit frameworks for those with side effects, so in this case, we’d have to write an HUnit test for this function. Let’s define the unit test which might satisfy those needs now.
import System.IO
import Test.HUnit
test_getOddList :: Test
test_getOddList =
TestCase $ do
inh <- openFile "test_getoddlist.txt" ReadMode
results <- getOddList inh
assertEqual "test should have three odds" [1,3,5] results
Then when we’re satisfied with writing this test, we then move onto the actual implementation in order to get this test to pass. This involves some IO work as we noted before in order to take a given Handle and extract the results line by line.
import System.IO
getOddList :: Handle -> IO [Int]
getOddList h = find 3 where
find 0 = return []
find x = do
ln <- hGetLine h
let ln’ = read ln::Int
if odd ln’ then do
tl <- find (x – 1)
return (ln’ : tl) else
find x
We can then verify our test using the GHCi by using the following to verify the results:
Cases: 1 Tried: 1 Errors: 0 Failures: 0
Counts {cases = 1, tried = 1, errors = 0, failures = 0}
We get the test to pass, but this isn’t very satisfying. The code looks enormously imperative, and to test all variations of odd numbers seems a bit daunting. Dealing with IO issues can also lead to brittle tests and not testing the core domain of our application, our algorithms. Instead, we’re putting too much effort into the IO part and not enough into where it matters most. What’ I’d prefer to write are QuickCheck property-based tests to define my behavior to cover all the variations of input to ensure the behavior of my functions.
We need to untangle the pure code from the side effecting code. We can rewrite the side effecting IO code to be just a simple thin layer on top of our algorithm. From there, we can tease out the algorithm and write the tests the way they should be written in this situation.
module RefactoringPure where
import Test.QuickCheck.Batch
prop_find3Odd_length :: [Int] -> Bool
prop_find3Odd_length xs =
length (find3Odd xs) <= 3
prop_find3Odd_odds :: [Int] -> Bool
prop_find3Odd_odds =
all odd . find3Odd
options = TestOptions
{ no_of_tests = 200,
length_of_tests = 1,
debug_tests = False
}
main = do
runTests "find3Odd" options
[ run prop_find3Odd_length,
run prop_find3Odd_odds
]
I’m much more satisfied with these property-based type checks instead, because they are less brittle and I’m now really testing the core logic of my domain. The IO code is now nowhere to be found in these tests. Now, let’s redo the functionality the way that it should be for this functionality that we want.
import Control.Applicative
import System.IO
getOddList’ :: Handle -> IO [Int]
getOddList’ h = (find3Odd . map read . lines) <$> hGetContents h
find3Odd :: [Int] -> [Int]
find3Odd = take 3 . filter odd
Once the functionality has been implemented, we can now run our main function to determine the results of our property-based tests.
find3Odd : .. (400)
What we’ve been able to accomplish here is to separate the core domain of our application from the IO required to receive the input. This is an important concept, no matter the paradigm between functional programming, object oriented programming or a hybrid approach of the two.
I didn’t mention F# in this conversation as there is no enforced purity to be had, but the concepts still easily apply in this situation. Below is a simple implementation of the Haskell code from above, in F# while isolating the side effecting code as a thin skin layer over top of our algorithm.
namespace CodeBetter.Samples
module RefactoringPure =
open FsCheck
open Xunit
let odd n = n % 2 <> 0
let find3Odd = List.take 3 << List.filter odd
let getOddList (r:System.IO.StreamReader) =
(find3Odd << List.map int << String.lines) (r.ReadToEnd())
let prop_find3Odd_length xs =
List.length (find3Odd xs) <= 3
let prop_find3Odd_odds =
List.for_all odd << find3Odd
[<Fact>]
let test_prop_find3Odd_length() =
check config prop_find3Odd_length
[<Fact>]
let test_prop_find3Odd_odds() =
check config prop_find3Odd_odds
You may notice there are a few functions that don’t exist in the base F# libraries, and over time, I’ve implemented most of the base Haskell List functions in F# that didn’t already have an F# equivalent such as String.lines, List.take and so on. I’ll cover what those functions are in a later post, because there are a few too many to mention at this point. There are issues when going back and forth from strings to lists due to them being Seq<char> instead of char list, but that’s another post as well.
Back to the Haskell world for just a minute, there are other ways of approaching the problem including abstracting the monads and associated types through type classes so that we’re independent of any concrete implementation, which we’ll cover next time.
Conclusion
Refactoring is an important part of writing code when considering the Red/Green/Refactor paradigm from TDD. By abstracting pure code from side effecting code, we can write effective tests using property-based checks using QuickCheck for our pure code, instead of more brittle tests which also include IO interaction. Techniques that will be enumerated in this series will help write more robust and concise functional programming code. | http://codebetter.com/matthewpodwysocki/2009/01/02/functional-programming-unit-testing-part-5/ | CC-MAIN-2017-30 | en | refinedweb |
The HUB has served as a role model by
- Angela O’Connor’
- 1 years ago
- Views:
Transcription
1 Claytn State University s Help Desk, The HUB, is the technical supprt fr the campus, including satellite lcatins. The HUB is cmprised f 35 student wrkers, 6 full-time staff, and ne Directr under the divisin f the Office f Infrmatin Technlgy and Services (OITS). The HUB wrks as Level 1 and Level 2 supprt fr ther departments within OITS. Our charge is t prvide technlgical supprt t apprximately 6,500 students and 1,400 faculty and staff. Describe hw yur nminee demnstrates cnsistently high levels f perfrmance while accmplishing nrmal jb respnsibilities. Describe hw the nminee is a rle mdel fr custmer service fr the University System f Gergia and the State f Gergia. Briefly explain the nminee s respnsibilities. Establish a histry f exceptinal perfrmance n the part f the nminee. Include recrds f utstanding perfrmance, such as high scres n custmer cmment cards r letters frm custmers and peers. Be sure t address all criteria fr the specific award categry. The HUB cnsistently prvides high levels f perfrmance while accmplishing nrmal jb respnsibilities by actively sliciting and respnding t custmer feedback and has ne f the highest satisfactin ratings n campus. Ninety percent f survey respndents in marked satisfied r very satisfied with the service prvided by the HUB. The We re Listening quality assurance prgram, implemented in 2011, actively slicits feedback thrugh multiple channels. a. The HUB s Custmer Satisfactin Survey (link sent via t every client wh receives service frm the HUB) measures the clients satisfactin and effectiveness f the HUB s training prgrams, plicies, and prcedures. b. Campus Quality Assurance Visits Invlves a full-time supervisr making nsite visits t faculty and staff t discuss, in persn, the service they received frm the HUB. c. Mystery Client Survey Clients visit the HUB with the intentin f grading the HUB n its effectiveness, custmer service, and adherence t its wn plicies. The results f these visits are reprted directly t the Directr f Client Supprt Services. Feedback gathered frm the We re Listening prgram is taken int accunt when examining service expansin fr clients. As a result f the feedback received, the HUB develped a system fr faculty t schedule appintments fr service, thereby aviding the lng lines fr service at semester startup. LANDesk LANDesk is a sftware tl implemented by the HUB in 2009 that allws the HUB t ffer self-help and remte supprt ptins. During FY 2012, the HUB leveraged several aspects f its LANDesk implementatin t prvide faster, mre reliable service, and self-service fr students, faculty, and staff. a. Self-service sftware installatins Faculty, staff, and students can nw self-install apprximately fifteen applicatins thrugh the sftware deplyment prtal. This is a time saver and a cnvenience. b. Remte supprt ptins thrugh LANDesk Clients nw have the ptin f allwing remte access t trublesht sftware prblems. c. Windws 7 migratin Migrating frm Micrsft Windws XP t Windws 7, via LANDesk prvisining remtely: Reduced the typical service time frm 5-6 hurs t 2-3 hurs, including backup and restratin f files and settings; Allwed service t prceed withut incnveniencing r relcating 325 clients during the upgrade; Mre efficient use f staff since a staff persn did nt have t physically attend t the cmputers. The HUB has served as a rle mdel by
2 Maintaining cnsistent custmer service ratings f 90+ percent f clients satisfied r very satisfied. The HUB pineered the student-staffed service desk mdel in 1997 and has served as a rle mdel t ther universities seeking t prvide supprt t students. In FY 2012, tw universities (Nrth Gergia Cllege and State University and Clumbus State University) made site visits t the HUB and apprximately ten universities have visited since the HUB pened in Describe hw this nminee's actins/accmplishments g abve and beynd nrmal jb duties. Describe hw the nminee has taken n additinal respnsibilities, making imprvements in the way service is delivered, r giving persnal time and resurces t serve custmers. Include specific examples, hw success was measured (baseline measures and current perfrmance measures that demnstrate imprvement), results f service, and the time frame when service was prvided. Be sure t address all criteria fr the specific award categry. New criteria this Year! Please include the nminee's internal custmer service perfrmance that resulted in imprved emplyee satisfactin fr ther state emplyees and/r facilitated their internal custmers' ability t prvide imprved service t their wn custmers. Awards r hnrs already given fr this effrt There s mre t it than just fixing cmputers, said ne f the HUB s student analysts. He s right. The HUB takes the user experience as tp pririty. We believe the HUB is changing the face f cmputer helpdesk supprt by incrprating custmer service and wrk ethics training int its technical training prgram, called HUB Certificatin. Abve and Beynd HUB Certificatin- While develping student staff persnally and prfessinally was never a charge r a requirement fr running a cmputer help desk, HUB full-time staff develped the HUB certificatin prgram t incrprate custmer service skills and wrk ethics int its technical training prgram. This led t what the HUB believes is the first campus help-desk certificatin training prgram that addresses ne f the biggest emplyment issues in Gergia. The U.S. Department f Labr estimates that 80 percent f wrkers wh lse their jbs d s nt because f lack f ccupatinal skills, but because f pr wrk ethics. (Gergia Department f Technical and Adult Educatin). The HUB Certificatin Prgram prvides training, testing, and measuring f the student staff s understanding and applicatin f slid wrk ethics and custmer service techniques. The HUB is graduating students with a very marketable set f skills, especially fr the technlgy industry. The HUB is wrking t prduce emplyees in Gergia wh will be hired nt because they have technical skills but because they als have custmer service skills and slid wrk ethics. The what s in it fr the HUB is that these students are prviding excellent custmer service n the frntline t its students, faculty, and staff because the HUB is investing in their futures. In return the student staffers are giving the HUB their best wrk. Cmments received frm student evaluatins f May 2012 Spirit training (a cmpnent f HUB Certificatin): Thank yu fr caring, nt just the class, but fr each ne f us. I really enjyed this sessin! There were very funny clips that helped tie in the ideas f accuntability. We als came up with gd ideas t make the HUB better. Cnfirmed hw t act prfessinally at wrk.
3 The HUB Certificatin prgram takes apprximately ne year fr an emplyee t cmplete and all student emplyees are required t participate. HUB Certificatin is a three-prng certificatin prgram that requires cmpletin f: 1. H+ Manual f technical tasks, custmer service, and exercises in wrk ethics 2. Spirit Week lng intensive training prgram, with guest speakers representing technlgy 3. PDP Prfessinal develpment plan Thirty-ne f the HUB s student analysts participated in the annual Spirit training in May 2012, and nine student analysts have becme HUB certified since July The remainder f the student staffers will participate in Spirit training in May f 2013 and are currently wrking tward their H+ Certificatin and PDP requirement. The HUB Certificatin prgram was develped and is implemented by HUB full-time staff frm a missin t be the best full service helpdesk with a visin f attracting student assistants interested in gaining marketable skills and experiences. Jyce Sandusky, Asst. Directr, Sftware Supprt/Training, recently shared the HUB Certificatin Prgram with Turner/CNN. This meeting resulted in cllabratins with CNN s technlgy services divisin. CNN acknwledged the need fr cllege students trained in custmer service techniques and wrk ethics in the technical field. Since that meeting, CNN has hired a third student analyst frm the HUB staff t wrk in their technlgy services divisin. Staff spent ut f pcket funds and weekend hurs n the HUB s Spirit training prgram. Full-time staff dnated persnal funds and weekends t purchase fd and training supplies in preparatin fr Spirit The budget fr Spirit 2012 training was $1,000. Half f the budget was funded by dnatins frm full-time staff and half was funded thrugh a spnsrship frm LANDesk. HDI Certificatins and Staff Develpment Six full -time staff members cmpleted HDI training and became certified and fur full-time staff members are LANDesk certified. Hw success was measured Visits frm ther universities t see hw we d business; The HUB received 244 surveys in FY 2012 frm clients reflecting a 90(+) percent rating f satisfied r very satisfied and shwing a dedicatin n the HUB s part t slicit feedback; Nine student staffers cmpleted HUB Certificatin prgram in FY 2012; Three HUB student staffers have btained full-time psitins this year with Turner/CNN because f the training and experiences they received at the HUB in FY2012. Nine student staffers have btained psitins with the Department f Defense, Claytn Cunty, DeKalb Medical, and Brwn & Brwn, since the HUB started tracking its alumni. Emplyers are making repeat hires frm the HUB student staff based n the training student staff are receiving at the HUB. See cmments belw frm clients f the HUB. The services are wnderful. Mr. Lng installed my sftware. He has a great persnality, knwledgeable, and very helpful. I truly believe his qualities spills ver t thers, which is awesme. Thank yu fr such a wnderful staff. I always feel appreciated and welcmed when I cme t the HUB. Please dn't change a thing, especially the staff persnalities. Ms. Jyce is the best... thank yu fr yur assistance. The HUB has wrked t serve its internal custmers this year by When the HUB began researching service desk sftware earlier this year, it partnered with Administrative Systems (anther department within OITS) t select a service desk tl that met the needs f the HUB and had a change management tl sufficient fr Administrative Systems auditing needs. Develpment and Implementatin f HUB Certificatin prgram fr student analysts.
4 THE HUB: ABOVE & BEYOND WE LISTE N G QUA E IN R The HUB is always lking fr ways t g abve and beynd the call f duty t be a standard f excellence t really bring meaning t the term HELP! desk. LITY ASSURANCE Our We re Listening prgram gives ur clients a vice an pprtunity t tell us hw we are ding and an pprtunity t tell us their technlgy needs. The numbers dn t lie. When surveyed, ur clients cnsistently find value in ur services. The metrics help us find areas we can imprve. LANDesk The newest tl in ur tlbx Faculty, students, and staff can ften get service withut visiting a lcatin, and the HUB can use its resurces fr thse services that are best prvided in persn.
5 The best way t imprve ur staff is t prepare them fr the future by investing in their technical knwledge and their life skills. HUB CERTIFICATION - WE TRAIN CONSISTENTLY - WE LEAD BY EXAMPLE - WE CARE ALWAYS The skills I learned at the HUB prepared me fr my career and taught me valuable life lessns. -Crey Wagner C er tificate f CmpletiN THIS AWARD IS PRESENTED TO Crey Wagner FOR SUCCESSFULLY COMPLETING ALL REQUIRED COURSEWORK AND TRAINING FOR SPIRIT 2012 DIRECTOR)
Resident Assistant Application JOB DESCRIPTION
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LATROBE COMMUNITY HEALTH SERVICE MANAGER, MARKETING AND COMMUNICATION JOB & PERSON SPECIFICATION
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AnswerDash Resurces Cntextual help fr sales and supprt Getting Started Guide AnswerDash is cmmitted t helping yu achieve yur larger business gals. The utlined pre-launch cnsiderat,,
Automation Technician Training Program. PRESENTED BY: Randy Phillips
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PART D. REVIEW OF GRADUATE PROGRAMS
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Internal Applicatins Only Receptinist Crprate Services AccessAbility Centre Salary Grade 3-15,456 t 17,678 per annum Open ended cntract Ref: CSE00955 At Leicester we re ging places. Ranked in the tp 20 | http://docplayer.net/1420114-The-hub-has-served-as-a-role-model-by.html | CC-MAIN-2017-30 | en | refinedweb |
#include <ida.h>
Inheritance diagram for InformationRecovery:
Definition at line 115 of file ida.h.
[inline, virtual, inherited]
Reimplemented from BufferedTransformation.
Definition at line 168 of file simple.h.
-1
true
Reimplemented from Multichannel< Filter >.
Definition at line 71 of file simple.h.
Reimplemented from Filter.
Definition at line 138 of file simple.h.
Definition at line 140 of file simple.h.
Implements BufferedTransformation.
Definition at line 142 of file simple.h.
Definition at line 144 of file simple 19 of file filters.h.
[inline, inherited]
return a reference to this object
This function is useful for passing a temporary BufferedTransformation object to a function that takes a non-const reference. Definition at line 711 of file cryptlib.h.
[virtual, inherited](). | http://cryptopp.sourceforge.net/docs/ref521/class_information_recovery.html | CC-MAIN-2017-30 | en | refinedweb |
:
- Continues to support the [Queryable] attribute, but also allows you to drop down to an Abstract Syntax Tree (or AST) representing $filter & $orderby.
- Adds ways to infer a model by convention or explicitly customize a model that will be familiar to anyone who’s used Entity Framework Code First.
- Adds support for service documents and $metadata so you can generate clients (in .NET, Windows Phone, Metro etc) for your Web API.
- Adds support for creating, updating, partially updating and deleting entities.
- Adds support for querying and manipulating relationships between entities.
- Adds the ability to create relationship links that wire up to your routes.
- Adds support for complex types.
- Adds support for Any/All in $filter.
- Adds the ability to control null propagation if needed (for example to avoid null refs working about LINQ to Objects).
- Refactors everything to build upon the same foundation as WCF Data Services, namely ODataLib..
[Queryable] aka supporting OData Query:
- The element type can’t be primitive (for example IQueryable<string>).
- Somehow the [Queryable] attribute must find a key property. This happens automatically if your element type has an ID property, if not you might need to manually configure the model (see setting up your model).
Doing more OData.
Setting up your model
The first thing you need is a model. The way you do this is very similar to the Entity Framework Code First approach, but with a few OData specific tweaks:
- The ability to configure how EditLinks, SelfLinks and Ids are generated.
- The ability to configure how links to related entities are generated.
- Support for multiple entity sets with the same type..
Setting up the formatters, routes and built-in controllers.
Adding Support for OData requests
In our model we added 3 entitysets: Products, ProductFamilies and Suppliers. So first we create 3 controllers, called ProductController, ProductFamiliesController and SuppliersController respectively.
Queries.
Get by Key.
Inserts (POST requests)).
Updates (PUT requests):
public HttpResponseMessage PatchProduct(int id, Delta<Product> product)
{
Product dbProduct = _db.Products.SingleOrDefault(p => p.ID == id);
if (dbProduct == null)
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}
product.Patch(dbProduct);
_db.SaveChanges();
return Request.CreateResponse(HttpStatusCode.NoContent);
}.
Deletes (DELETE requests).
Following Navigations.
Creating and Deleting links();
return Request.CreateResponse(HttpStatusCode.NoContent);
});
}
Conclusion!
Next up
This blog post doesn’t cover everything you can do with the Preview, you can use:
- ODataQueryOptions rather than [Queryable] to take full control of handling the query.
- ODataResult<> to implement OData features like Server Driven Paging and $inlinecount.
- EntitySetController<,> to simplify creating fully compliant OData entitysets.
I’ll be blogging more about these soon.
Enjoy!
I believe there is an issue with the NuGet Package. I'm getting this message:
Attempting to resolve dependency 'System.Spatial (= 5.0.1)'.
Already referencing a newer version of 'System.Spatial'.
I don't see this DLL anywhere in my Project. So I tried adding the NuGet Package - System.Spatial -Pre, but noticed that it's version is 5.1.0, not 5.0.1 (as stated in the Dependencies on the NuGet Page). Am I doing something wrong?
Hello,
Could we use it with EntityFramework 4.3 ?
I've just upgraded my API project to the new packages released today.
However, when I try to install WebApi.OData, it seems to have a redundant reference to System.Spatial.
Which breaks, because it requires the explicit 5.01 version, when I'm on System.Spatial 5.1.0-rc1.
Here's my output:
PM> Install-Package Microsoft.AspNet.WebApi.OData -Pre
Attempting to resolve dependency 'Microsoft.Data.Edm (= 5.0.1)'.
Attempting to resolve dependency 'Microsoft.Data.OData (= 5.0.1)'.
Attempting to resolve dependency 'System.Spatial (≥ 5.0.1)'.
Attempting to resolve dependency 'Microsoft.Net.Http (≥ 2.0.20710.0 && < 2.1)'.
Attempting to resolve dependency 'System.Spatial (= 5.0.1)'.
Install-Package : Already referencing a newer version of 'System.Spatial'.
At line:1 char:16
+ CategoryInfo : NotSpecified: (:) [Install-Package], InvalidOperationException
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand
Notice that System.Spatial is referred on lines 4 and 6.
thanks,
Jaume
This is really cool, looking forward to digging into it.
The links to the sample projects in the post aren't quite right, but I was able to find them here: aspnet.codeplex.com/.../903afc4e11df
For those who tried the nuget packages earlier and had problems. There were some issues with dependencies caused by a new version of ODataLib going out at the same time as this Nuget package. This mean't some dependency version numbers didn't line up.
Hopefully this has been resolved by the time you read this!
When will projection be supported
@Steve, thanks for that I think I've updated things now.
@Doug. We are hoping to add projection support in the next 3-4 months. That said projections does present some real challenges to the existing web-api infrastructure, so I'm not quite sure how this will work yet!
@Kakone. Yes. You can use it with any backed. Basically all it needs is an implementation of IQueryable. And even that isn't mandatory if you drop down to using ODataQueryOptions instead of using [Queryable]
This is great. Happy to have it out at the release of VS 2012 and .NET 4.5 as promised.
I have the demo up and running but I don't understand how to implement ODataResult. You mentioned an upcoming blog post but if you could just get me pointed in the right direction with a line or two of code that'd be great.
I'm using ODataQueryOptions and that's going well. It's just ODataResult I'm struggling with. It appears to be designed as a wrapper for the OData responses adding count and paging details. I'm just not sure how to build the response or what I should be using as my controller's return type. Think I just need to see some code.
Oh, and the most important parameter is still not supported!!! $select is doa! Not good at all.
At least with the old hack code that was in I had $filter, $top/take, $inlinecount, $format, $skip, and a few others and it worked with ALL IQueryables.
This solution doesn't handle half of the odata spec, AND doesn't work properly with anything other than EntityFramework.
I'd rather have the hack stuff from the RCs back!
@Mark,
You use ODataResult<T> like this (pseudo-code):
public ODataResults<Product> Get(ODataQueryOptions options)
{
var results = (options.ApplyTo(_db.Products) as IQueryable<Product>);
var count = results.Count;
var limitedResults = results.Take(100).ToArray();
return new ODataResults(results,count,null);
}
This basically mimics the old ResultLimit stuff. Implementing Service Driven Paging is more involved, you have to work out a nextLink (null above) that continues from this page...
I'll need a full blog post to cover that.
-Alex
@James
Our goal for the preview was to get back to parity with the old implementation of [Queryable] with a better foundation which we've done. Next up is support for things like $select etc. In the meantime if you want to implement $select you can always drop down to ODataQueryOptions and work it out yourself.
Oh and this supports any backend, not just EF, yes the sample uses EF but actually it was designed to work against any backend, including those that don't have IQueryable implementations. ODataQueryOptions gives you really low level access so you can go directly from an AST representing the query to whatever query language you have. For example you could translate the AST into SQL directly and use ADO.NET directly bypassing EF if you want.
-Alex
Oh and $orderby doesn't support multiple fields
@Alex: The problem with ODataQueryOptions if I understand correctly is that I would have to put these on every single method to implement them. Obviously this isn't DRY. I should be able to go and intercept these in an override of the Queryable attribute and handle them myself there in a global way.
@James
$orderby does support multiple fields. It does have some limitations though, currently it doesn't support paths i.e. $orderby=Category/Name but that will come soon.
The point with ODataQueryOptions is you have access to exactly the sample building blocks as [Queryable], which basically just called _options.ApplyTo(query) for you. If you could easily write your own Action Filter that does this work globally if you need it before we add it to [Queryable]
Okay. I just had a namespace issue and was referencing the abstract class. This works fine:
public ODataResult<Product> Get(ODataQueryOptions options)
{
var results = (options.ApplyTo(_db.Products) as IQueryable<Product>);
var count = results.Count;
var limitedResults = results.Take(100).ToArray();
return new ODataResult<Product>(results,null,count);
}
Is it possible to use the [Queryable] attribute with HttpResponseMessage as the return type?
@Azzlack
Currently it isn't but I can see how it would be implemented. Can you explain your scenario?
-Alex
Yes. I need to be able to return custom response types based on the the result of a database query.
I.e. A function Get() that is supposed to get all Buildings from a database. If there are no buildings, then I want to return a 204 No Content with a custom message as the content. If everything is ok, then return the standard 200 OK with the result as IQueryable. Secondly, I would also like to be able to set other http headers for the response.
Also, it seems like a lot of the source code for the OData support (ODataQueryOptions and ODataQueryContext) is heavily geared towards EF, and as far as I could see, very difficult to adapt to other things like MongoDB (which is what I'm using).
Here is a sample:
[Queryable]
public async Task<HttpResponseMessage> Get()
{
var result = await this.buildingRepository.Get();
// Return 204 if there is no content
if (result == null || !result.Any())
{
return Request.CreateResponse(HttpStatusCode.NoContent, "No Buildings exist");
}
return Request.CreateResponse(HttpStatusCode.OK, result.AsQueryable());
}
Azzlack,
That's not how OData works when there is no data. The point of the library is to allow you to build WebApi code that also conforms to the OData spec. What you suggest would not work with an OData client library.
It sounds like what you want is just a regular WebApi library.
Robert McLaws
twitter.com/robertmclaws
Azzlack,
It sounds like what you want is to just leverage $filter but to not implement an OData compliant service - we did something similar recently (see part 4 of this series of blog posts) - but I'm not sure this is really something the Microsoft.AspNet.WebApi.OData library should aim to really make "easy" or even possible, as it's steering the developer away from the pit of success that is being OData compliant.
In fact I think if I did this again I would drop using the $ at the start of the parameter names to avoid the confusion with a real OData compliant service.
@AlexJames - am I right in thinking that what I do here:
blog.bittercoder.com
Wouldn't be easy to build with current preview? (I haven't had a chance to install and use the preview just yet.. but looking forward to giving it a test drive this week 🙂
Cheers,
Alex
@Robert McLaws, @Alex Henderson Yes. I only need to be able to use $filter, $skip, etc. not be completely OData compliant.
Your blog post looks really interesting. Maybe it will solve my problems.
@Azzlack
I'd advise against returning 204 No Content whether you are using OData format or not. My reasoning is this, client libraries often convert the results of queries to collections or enumerations, and if you return No Content rather than an empty enumeration you are forcing clients to write special code to either deal with exceptions or use libraries that seemlessly consume No Content and convert into empty enumerations.
We made a similar mistake with the first version of the Data Services client library, for example this query
GET ~/Products(5) could easily return 404 Not Found, yet it is generated by this LINQ code on the client:
ctx.Products.Where(p => p.ID == 5)
And from the client programmers perspective there is no difference between that and say:
ctx.Products.Where(p => p.Category.Name == "Food")
If there were no matches for either query, you would expect the same coding patterns to apply, unfortunately in the first we raised an exception, in the second you got an empty enumeration (which is what people generally want).
We addressed this by adding a configuration switch to convert 404's into empty enumerations...
So if you use 204 No Content you are
1) Not OData compliant (which it sounds you are fine with)
2) Complicating client logic
As for ODataQueryOptions and ODataQueryContext being tied to EF. Quite the contrary, they are not at all, indeed they are designed to be used with any backend, hence you get access to an AST. We do though make it easy to convert that AST into expressions and bind to an IQueryable (any IQueryable) if you have one.
-Alex
I see your point. Will returning 204 No Content and an empty enumeration be better?
According to @Henrik F Nielsen returning result.AsQueryable() should work with OData queries. However, I keep getting errors like this one: The method 'BaseMongoEntity.get_Id' is not a property accessor" and "The type 'Time' cannot be configured as a ComplexType. It was previously configured as an EntityType.".
The Id property from the first one is set on an abstract base class.
The Time property is a new property, meaning that some entities in the database has the value null.
@Azzlack,
Today you need strongly typed properties for all your OData Properties. I.e. we don't yet support using methods like get_Id(). It is however on the roadmap to add 'virtual properties' that map to a custom get() and set() method.
Re - Time: it is hard to know which limitation you are running into: I'd be merely speculating until I get a better idea of your class structure.
-Alex
@Azzlack,
Oh and I don't know how you return an empty enumeration and 204 No Content, I think 204 implies no body right, so where would you put the empty enumeration?
-Alex
@Alex H
I think what you are doing with $filter would be trivial to support using the new bits.
You get access to an AST representing the Filter, i.e. ODataQueryOptions.Filter.QueryNode and that you could translate directly to whatever query language you need.
Alternatively you can use ODataQueryOptions.Filter.ApplyTo(queryable) too 🙂
If you drop down to ODataQueryOptions you can explicitly fail if there is something in the query you don't support. ODataQueryOptions.ApplyTo basically automatically applies the Filter, OrderBy, Top, Skip for you.
Note: unhandled OData options as raw strings are available via ODataQueryOptions.RawValues.
@Ales D James
Here is the property it is complaining about with the get_Id error:
public abstract class BaseMongoEntity
{
[BsonId]
public string Id { get; set; }
}
And here is the Time class:
public class Time
{
public int Hours { get; set; }
public int Minutes { get; set; }
public int Seconds { get; set; }
public double Milliseconds { get; set; }
}
Alex, I'm getting a 206 Not Acceptable for any action on a GET that passes in $ options. Any ideas on how to troubleshoot?
Thanks!
-Robert
Having a small issue with the $metadata being produced using webapi. I am using CodeFirst and i find that when I expose my context with the EntitySetController with all of the routes set up as explained in the post, I get my metadata when requested, but it doesn't have any of the validation build in. When I expose the same CodeFirst model using WCF Data Services, the metadata contains all validation.
For example, when using the WebApi EntitySetController, i get metadata like:
<Property Name="Id" Type="Edm.Int32" Nullable="false"/>
<Property Name="Email" Type="Edm.String"/>
And when using the WCF DataServices, I get the following metadata for the exact same properties
<Property Name="Id" Type="Edm.Int32" Nullable="false" p8:
<Property Name="Email" Type="Edm.String" Nullable="true" MaxLength="4000" Unicode="true" FixedLength="false"/>
Is this just due to the Microsoft.AspNet.WebApi.OData library being alpha, or am I missing something in how the EdmModel or ODataMediaTypeFormatter is set up?
@Alex
Thanks for the update - definitely going to have to give the AST a further look, sounds like potentially we could leverage that with some basic translation/visitors to get the queries expressed as a query object we can pass into our business layer for those parts of the app which don't use our bespoke query language (translating to our bespoke query language would be even easier as that's expressed as an AST as well... )
Keep up the great work 🙂
Cheers,
Alex H
Any idea how to solve this problem with the latest NuGet package?
I've found that if you have a Get method decorated with the Queryable attribute it will fail with "navigation property not found" if the objects returned extend a base class with a List in it. Ex:
public class Base
{
int Id {get; set;}
List<string> Links {get; set;}
}
public Company : Base
{
string Name { get; set;}
}
[Queryable]
public IQueryable<Company> Get()
{
....
}
@clients
I think this is a misunderstanding about how the Web API model builders work. The Model builders, both explicit and by convention, don't know about the underlying EF model, they create/infer a completely new model. So it is not surprising they are different. Perhaps there are things missing from the Model Builder I invite you to create issues for them on the CodePlex site.
That said we would like to add a way to initialize the OData model from the EF model, but it is very important that the two can differ, i.e. you would start from the EF model and then tweak to hide properties sets etc, that shouldn't be exposed via the service.
@David
Where does the error occur? Do you build the model explicitly or do you let [Queryable] build it for you.
Either way it sounds like a bug. Can you report it on the CodePlex site?
@Robert
I think I just saw a bug (and fix) for this aspnetwebstack.codeplex.com/.../327
@Ove
Sorry from what you've shown me I have no idea what is going on. Perhaps you can isolate the issue and file a bug on the codeplex site?
@georgiosd
Yes as a protocol designer I've run into issues with not having places to annotate data. So things like "results" wrappers are vital.
In OData V3 the default format is something called JSON Light, which looks a lot like the JSON you might write by hand. It is structured such as to provide convenient places for annotations. The ODataLib foundation upon which the Web API OData formatter is built is currently being extended to support JSON light and annotations. Once that is done we will update Web API so that it supports this light form for JSON and we'll then look at providing mechanisms for you to annotate responses too.
That said I think that is a little while off, probably at least 3 or so months.
See this for more on JSON light: skydrive.live.com
@Alex D James
Thanks for the information. I will look into the Model Builder some more. I agree that being able to change the external facing model is very important.
I have a nulllable DateTimeOffset property declared in my model. In the rc of the web api, I used a filter query as follows $filter=LastTransmissionTimestamp eq null which worked fine. With the release version and the new odata extensions, this same filter now gives the following error:
A binary operator with incompatible types was detected. Found operand types 'Edm.DateTimeOffset' and '<null>' for operator kind 'Equal'.
Is there a work around/fix for this issue?
Thanks
@Kevin.
Unfortunately not. The issue is in ODataContrib, it has a lot of problems with DateTimeOffset at the moment,
My best guess is that fixes for this are about 6 weeks away.
Can we get an example of how to use the patch method. I am trying something like this
<Employee>
<BirthDate>1977-01-01T00:00:00</BirthDate>
</Employee>
However I get
<Error><Message>The request is invalid.</Message><ModelState><updates>Error in line 1 position 12. Expecting element 'DeltaOfEmployeepwN2u9vl' from namespace 'schemas.datacontract.org/.../System.Web.Http.OData&.. Encountered 'Element' with name 'BirthDate', namespace ''. </updates></ModelState></Error>
I'm getting the following exception, any ideas?
Method 'get_Handler' in type 'System.Web.Http.WebHost.Routing.HostedHttpRoute' from assembly 'System.Web.Http.WebHost, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' does not have an implementation.
@Alex James
Great work on this so far! I'm liking the ease of setup combined with the ability to easily explicitly control things (like ODataQueryOptions). Do you know what the rough timeline for this to be RTM is? Thanks again, keep up the good work!
I've built a small test app and everything seems to be working fine, so I thought I'd hook it up to PowerPivot and connect to the OData feed. I get no exception thrown within my test app, but PowerPivot reports 'The remote server returned an error: (500) Internal Server Error'. Any idea what the problem might be?
Alex - a few places in the article you state that [Queryable] needs to be able to figure out the ID property, or you need to setup the model to indicate the ID property.
What are the rules for oData figuring out the ID property? Name? Case sensitive? First int field? If possible looks at EDXM model for key?
Please post an update to the microsoft.aspnet.webapi.odata package... I can't update my Odatalib nuget package because you guys have it hard coded to a specific version.
@Blake, add this source to your NuGet package source list
This will allow you to install using NuGet from the nightly build
I'm getting confused about OData flow:
Database server returns to Web API a list containing all users
Web API filters the data returned by Database throughout linq (if the client wants to filter something)
Web API returns to the client the filtered Data
Being more accurate I am asking myself:
you send your sentence to the database server and then if you want to filter OData filter it for you BUT after receiving the data from the database server.
@SoyUnEmilio
The filtering occurs in the database if your action returns IQueryable, and in memory if your action return IEnumerable... so you are in control here.
-Alex
@Alex D James
Just wondering if that 'Server side paging' blog post was far away? I am keen to implement something using WebAPI and Odata but am holding out until I can read a bit more on it | https://blogs.msdn.microsoft.com/alexj/2012/08/15/odata-support-in-asp-net-web-api/ | CC-MAIN-2017-30 | en | refinedweb |
I receive a JSON with 30 fields, and my entity is built from this JSON.
The problem is: two fields shouldn't be updated (two dates).
If I use
entity.merge
This article explains in great details your question, but I'm going to summarize it here as well.
If you never want to update those two fields, you can mark them with
updatable=false:
@Column(name="CREATED_ON", updatable=false) private Date createdOn;
Once you load an entity and you modify it, as long as the current
Session or
EntityManager is open, Hibernate can track changes through the dirty checking mechanism. Then, during flush, an
SQL update will be executed.
If you don't like that all columns are included in the
UPDATE statement, you can use dynamic update:
@Entity @DynamicUpdate public class Product { //code omitted for brevity }
Then, only the modified columns will be included in the
UPDATE statement. | https://codedump.io/share/Zao3loOR6b91/1/how-to-update-only-a-part-of-all-entity-attributes-with-hibernate | CC-MAIN-2017-30 | en | refinedweb |
Sony Playstation 4 (PS4) - WebKit 'setAttributeNodeNS' User After Free Write-up
EDB-ID:
44230
CVE:
N/A
Become a Certified Penetration Tester
Enroll in Penetration Testing with Kali Linux and pass the exam to become an Offensive Security Certified Professional (OSCP). All new content for 2020.
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**Note: While I exploited this bug on the PS4, this bug can also be exploited on other unpatched platforms. As such, I've published it under the "WebKit" folder and not the "PS4" folder.** # Introduction In around October of 2017, a few others as well as myself were looking through project zer0 bugs to see which ones could work on the latest FW of the PlayStation 4, which at the time was 5.00. I stumbled across the setAttributeNodeNS bug, and happily (with a majority of the work being done by qwertyoruiopz), we were able to achieve userland code execution in WebKit. While we were writing this exploit, qwerty helped me understand what was happening, and I ended up learning a lot from it, so I hope through this write-up, those interested could learn about WebKit internals - I've tried to ensure the write-up is for the most part beginner friendly. The exploit was patched in firmware 5.03. This write-up will only cover the userland aspect of the 4.55 full jailbreak chain, however you can find the kernel part here (to be released at a later date). # The PoC (proof-of-concept) The proof of concept for this exploit can be found on the [Chromium bug page](). This bug was reported by lokihardt from Google Project Zer0. The bug can be found in `Element::setAttributeNodeNS()`. Let's take a look at a code snippet: ```cpp ExceptionOr<RefPtr<Attr>> Element::setAttributeNodeNS(Attr& attrNode) { ... setAttributeInternal(index, attrNode.qualifiedName(), attrNode.value(), NotInSynchronizationOfLazyAttribute); attrNode.attachToElement(*this); treeScope().adoptIfNeeded(attrNode); ensureAttrNodeListForElement(*this).append(&attrNode); return WTFMove(oldAttrNode); } ``` Notice that the function calls `setAttributeInternal()` before inserting / updating a new attribute. As stated by the bug description, `setAttributeNodeNS()` can be called again through `setAttributeInternal()`. If this happens, two attribute nodes (Attr) will have the same owner element. If one were to be free()'d, the other attribute will hold a stale reference, thus allowing a use-after-free (UAF) scenario. Let's take a look at the PoC: ```html <body> <script> function gc() { for (let i = 0; i < 0x40; i++) { new ArrayBuffer(0x1000000); } } window.callback = () => { window.callback = null; d.setAttributeNodeNS(src); f.setAttributeNodeNS(document.createAttribute('src')); }; let src = document.createAttribute('src'); src.value = 'javascript:parent.callback()'; let d = document.createElement('div'); let f = document.body.appendChild(document.createElement('iframe')); f.setAttributeNodeNS(src); f.remove(); f = null; src = null; gc(); alert(d.attributes[0].ownerElement); </script> ``` In environments where the bug is unpatched, alert() will report an instance of the iframe object. In patched environments, the code will fail and hit an exception, because `d` should be `undefined`. I am happy to say that alert() will report an instance of the iframe object up to and including firmware 5.02. ## Important Note about WebKit Heap WebKit sections it’s heap into arenas. The purpose of these arenas is not only to organize objects in their own pools, but to also mitigate heap exploits by controlling what type of objects you can corrupt in your immediate arena. The object we have a use-after-free for is an iframe object, which is `fastmalloc()`'d. This will be in the WebCore arena. WebCore objects are not too interesting for primitives, our eventual goal is to obtain a read/write primitive via a misaligned uint32array. We need to move from WebCore heap corruption to JSCore heap corruption. Keep this in mind for the rest of the exploit, as it is a vital to it’s success. # Stage 1: Information Leak ## Introduction We need to leak a pointer to a JSValue in the JSCore heap that we want to corrupt. Unfortunately our leak is also a WebCore leak as the backing memory is `fastmalloc()`’d, so we need an object that is both `fastmalloc()`’d and contains pointers into the JSCore heap. MarkedArgumentBuffer is a great target. For more information on MarkedArgumentBuffer and how it can be used in exploits, see the [Pegasus write-up](). ## Vector: postMessage() We can create an "ImageData" object (see [ImageData]()) and call `postMessage()` with a null message and no origin preference, and use our instance of the ImageData object as the transfer. By then pushing the state of the object into the session history, the backing memory for the `ImageData.data` object is allocated but not initialized. We can actually access this backing memory via` history.state.data.buffer` as a Uint32array. This means not only can we access uninitialized heap memory, we can control the size of the leak. We can setup the heap to leak a JSObject. Creating our own JSObject is very trivial, and can be done like so: ```javascript var tgt = {a:0,b:0,c:0,d:0}; ``` We can then spray the heap with our JSObject of `tgt` and leak it using the ImageData object's backing memory, `.data.buffer`. ```javascript var y = new ImageData(1, 0x4000); postMessage("", "*", [y.data.buffer]); var props = {}; for (var i=0; i<0x4000/(2); ) { props[i++] = {value:0x42424242}; props[i++] = {value:tgt}; } // ... history.pushState(y,""); Object.defineProperties({}, props); var leak = new Uint32Array(history.state.data.buffer); ``` ## Leaking a JSValue Our goal of this leak is to be able to leak a JSValue, but how can we do this? The answer is JSObjects. We can easily create one, and not only will this object allow us to leak JSValues, but we will also use it in a later stage to obtain a read/write primitive (more on that later). For now, let's look at how JSObjects look in memory (for more information on JSObject internals, see the ["Attacking Javascript Engines"]() paper by Saelo@Phrack). I've written it as a C structure in pseudocode and provided the offsets as comments, in reality it's a bit more complex, but the concept remains. ```c struct JSObject { JSCell cell; // 0x00 Butterfly *butterfly; // 0x08 JSValue *prop_slot_1; // 0x10 JSValue *prop_slot_2; // 0x18 JSValue *prop_slot_3; // 0x20 JSValue *prop_slot_4; // 0x28 } ``` For this write-up, we will mostly ignore the "cell" and "butterfly" members. Just know that "cell" contains the object's type, structure ID, and some flags. The butterfly pointer will be null, because since we are only using 4 properties, a butterfly is not needed. Notice how we have access to JSValue pointers in offsets 0x10 - 0x30? We're going to use slot 2 (labelled 'b' in the target object) to leak JSValues. As a reminder, here's a definition of target: ```javascript var tgt = {a:0,b:0,c:0,d:0}; ``` To leak the JSValue from 'b', we will need to put our target object inside some other object that we can spray on the heap, such as a MarkedArgumentBuffer. If we set some properties of the object to our target JSObject `tgt`, we will be able to leak it in memory, as it will be inlined. If we add less than 8 properties, the object will be allocated on the stack (this is for performance reasons). We need our object to be in the heap. Additionally, larger objects are used less and are therefore more reliable, so we will add `0x4000` properties to our MarkedArgumentBuffer object. In our spray, we will set every second element to `0x42424242` (“BBBB”) and every other element to `tgt`. This will allow us to both ensure the integrity of the leak (by checking against `0x42424242`) and allow us to extract information out of our JSObject. The exploit further verifies that we’re leaking the correct object by checking the JSObject's properties against known values. ```javascript for (var i=0; i < leak.length - 6; i++) { if (leak[i] == 0x42424242 && leak[i+1] == 0xffff0000 && leak[i+2] == 0 && leak[i+3] == 0 && leak[i+4] == 0 && leak[i+5] == 0 && leak[i+6] == 14 && leak[i+7] == 0 && leak[i+10] == 0 && leak[i+11] == 0 && leak[i+12] == 0 && leak[i+13] == 0 && leak[i+14] == 14 && leak[i+15] == 0) { foundidx = i; foundleak = leak; break; } } ``` Keep in mind `leak` is a Uint32array, meaning each element is 32-bits wide. Index 0 and 1 contain the JSValue of our `0x42424242` immediate value (index 1 is set to `0xFFFF0000` because this is the upper prefix for a 32-bit integer). Also keep in mind we're in Little Endian, which is why element `0` contains the lower 32-bits of the JSValue and element 1 the upper 32-bits. Notice that we can leak the JSValue of the second property ('b') of the JSObject at index 8 and 9 (6 indexes * 4 bytes = 0x18 (prop_slot_2) + 0x08 for the `0x42424242` JSValue). ```javascript var firstLeak = Array.prototype.slice.call(foundLeak, foundIndex, foundIndex + 0x40); var leakval = new int64(firstleak[8], firstleak[9]); leakval.toString(); ``` # Stage 2: Trigger UaF ## Introduction Because we maintain a double reference to the iframe, when it is free()'d by garbage collection, one reference will be cleared however the other will not be. This allows us to maintain a stale reference. This is important, because we can corrupt the backing JSObject of the iframe object by spraying the heap, and control the behavior of how the stale object is used. For instance, we can control the size of the buffer, the pointer to the backing memory (called "vector"), and the butterfly. ## Memory Pressure Now that we've leaked a JSValue, we're going to trigger the free() on our iframe by applying memory pressure to force garbage collection by calling `dgc()`. `dgc()` is defined as the following: ```javascript var dgc = function() { for (var i = 0; i < 0x100; i++) { new ArrayBuffer(0x100000); } } f.name = "lol"; f.setAttributeNodeNS(src); f.remove(); f = null; src = null; nogc.length=0; dgc(); ``` # Stage 3: Heap Spray ## Introduction The JSObject representing our iframe is free, as well as it's butterfly. Again, iframe objects are `fastmalloc()`'d, meaning our spray vector must also be `fastmalloc()`'d. Our old friend ImageData does the trick. We cannot allocate Uint32Array's of size 0x90 and have it `fastmalloc()`'d, but we need to access the data via a Uint32Array. We can get around this by first spraying a bunch of ImageData objects on the heap (Uint8Array) then converting to Uint32Arrays after. On the heap, iframe objects are of size 0x90 on the PS4. We can control the size of the MarkedArgumentBuffer we spray via the ImageData "width" and "height" parameters. Since each value is represented by 32-bits (or 4 bytes) and ImageData is backed by a Uint8Array, we divide the height by 4. ```javascript for (var i=0; i < 0x10000; i++) { objs[i] = new ImageData(1,0x90/4); } for (var i=0; i < 0x10000; i++) { objs[i] = new Uint32Array(objs[i].data.buffer); } ``` ## Memory Corruption Now we've sprayed the heap with a bunch of objects, but we haven't really corrupted memory yet. Our next task is to loop through all the objects we created, and set their butterfly values to `leakval + 0x1C`. This will allow us to smash the butterfly easily via the 'b' property of the target. Notice we're overwriting indexes 2 and 3 as each index is 32-bits wide, so index 2 is offset 0x8 (which is the lower 32-bits of the butterfly) and index 3 is offset `0xC` (which is the upper 32-bits of the butterfly). ```javascript for (var i=0; i<objspray; i++) { objs[i][2] = leakval.low + 0x18 + 4; objs[i][3] = leakval.hi; } ``` # Stage 4: Misaligning JSValues ## Introduction Our next objective is to misalign a JSValue so we can control the JSObject's JSCell, Butterfly, Vector, and Length. We can do this by taking the leaked JSValue we have from the infoleak and add 0x10 to the pointer. This will allow us to create a fake JSArrayBufferView inside the JSObject's inline property storage, and control meta-data that we otherwise could not control. (credits: qwertyoruiopz) ## Note Notice in the screenshot that the structure of "Uint32Array" differs slightly from a JSObject. To avoid confusion, we will refer to this "Uint32Array" meta-data structure as JSArrayBufferView (which is the class that Float64Array's inherit) to avoid confusing it with the Uint32Array type. ## Misalign + Type Confusion First, we'll grab a pointer to our fake JSArrayBufferView. As mentioned earlier, we're going to create it via the target's properties at offset 0x10, so we can take the leaked value and add `0x10` to it. ```javascript var craftptr = leakval.sub32(0x10000 - 0x10) ``` This line may seem strange at first, but notice that due to double encoding, this line translates to `leakval.sub32(-0x10)`, or simply `leakval.add32(0x10)`. Then we need to fake the JSCell of a JSObject using the target's first property, and fake the butterfly to point to the leaked object itself, and the vector to the upper 32-bits of the leaked object. What we are essentially doing here is creating *Type Confusion* in the heap via the JSCell to create a fake JSArrayBufferView. ```javascript tgt.a = u2d(2048, 0x1602300); tgt.b = u2d(0,craftptr.low); tgt.c = craftptr.hi; ``` # Stage 5: Read/Write Primitive ## Introduction Read/Write primitives are very powerful, and can allow us to later obtain code execution. For a R/W primitive, we need two buffers. The first is a master, this will allow us to set the address to write to in the case of writing, or the address to read from in the case of reading. The second is a slave, which will either be used to set the value at the master's address if writing, or read the value from the master's address if reading. We will also allocate a third buffer that will be used to help leak JSValues. ```javascript var master = new Uint32Array(0x1000); var slave = new Uint32Array(0x1000); var leakval_u32 = new Uint32Array(0x1000); ``` ## Important Note The following bit can be confusing if you don't understand this section. While `tgt` and `stale` *currently* overlap, they don't stay that way. By writing to `tgt.c`, we control where `stale` points. This means in the following section, when you see something such as the following: ```javascript tgt.c = master; stale[4] = leakval_u32[0]; stale[5] = leakval_u32[1]; ``` The first line sets `stale` to the JSArrayBufferView of the `master` Uint32array, and the second and third sets the "vector" pointer of the `master`'s JSArrayBufferView. This means we can control properties of the JSArrayBufferView via `stale`. Below is a diagram to provide a visual aid. ## Read/Write Primitives We're going to create a fake JSArrayBufferView inside the JSObject that we've set. This is trivial, we just need to change `tgt.a`'s JSCell ID to that of a JSArrayBufferView, and treat `b`, `c`, and `d` as `butterfly`, `vector`, and `length` respectively. ```javascript var leakval_helper = [slave,2,3,4,5,6,7,8,9,10]; tgt.a = u2d(4096, 0x1602300); tgt.b = 0; tgt.c = leakval_helper; tgt.d = 0x1337; ``` Notice we're setting the fake JSArrayBufferView's vector to a real JSArrayBufferView (leakval_helper). The first value is set to the `slave` buffer for leaking JSValues, the rest of the values are filler to ensure that a butterfly is allocated. Before we setup our primitives, we need to setup the handles to the buffers they will be using. First we'll store the butterfly's value from `leakval_helper`'s JSArrayBufferView - this is primarily used for creating and leaking JSValues, which is important later for gaining code execution. ```javascript tgt.c = leakval_helper; var butterfly = new int64(stale[2], stale[3]); ``` We'll want to setup some buffers to help us leak and create JSValues. We'll do this by setting `tgt.c` to the address of the `leakval_32` buffer we setup earlier. First we'll want to store the old "vector" value so we can restore it later. Then we will set the "vector" to `leakval_helper`'s butterfly which has the `slave` buffer. ```javascript tgt.c = leakval_u32; var lkv_u32_old = new int64(stale[4], stale[5]); stale[4] = butterfly.low; stale[5] = butterfly.hi; ``` Now we want to setup the buffers for our read/write primitive. By setting `master`'s "vector" to the address of the `slave` Uint32Array, we can easily establish a read/write primitive. We can control where `slave` points via the "vector" of `master`. Therefore, by setting up `master[4]` and `master[5]` with the address of where we want to write, and `slave[0]` and `slave[1]` with the value we want to write, we can establish a write primitive. Similarily, by setting up `master[4]` and `master[5]` with the address of where we want to read from, we can retrieve our value from `slave[0]`, and `slave[1]` as well if the value is a 64-bit value. ```javascript tgt.c = master; stale[4] = leakval_u32[0]; // 'slave' read from butterfly of leakval_u32 stale[5] = leakval_u32[1]; var addr_to_slavebuf = new int64(master[4], master[5]); tgt.c = leakval_u32; stale[4] = lkv_u32_old.low; stale[5] = lkv_u32_old.hi; var prim = { write8: function(addr, val) { master[4] = addr.low; master[5] = addr.hi; if (val instanceof int64) { slave[0] = val.low; slave[1] = val.hi; } else { slave[0] = val; slave[1] = 0; } master[4] = addr_to_slavebuf.low; master[5] = addr_to_slavebuf.hi; }, write4: function(addr, val) { master[4] = addr.low; master[5] = addr.hi; slave[0] = val; master[4] = addr_to_slavebuf.low; master[5] = addr_to_slavebuf.hi; }, read8: function(addr) { master[4] = addr.low; master[5] = addr.hi; var rtv = new int64(slave[0], slave[1]); master[4] = addr_to_slavebuf.low; master[5] = addr_to_slavebuf.hi; return rtv; }, read4: function(addr) { master[4] = addr.low; master[5] = addr.hi; var rtv = slave[0]; master[4] = addr_to_slavebuf.low; master[5] = addr_to_slavebuf.hi; return rtv; } // ... } ``` ## JSValue Leak/Create Primitives Notice that earlier we ensured a butterfly was created for `leakval_helper` by setting up more than 4 values. Also notice that we've set `leakval_32` up so that we can write to `leakval_helper`'s own butterfly, as we've set `tgt.c` to `leakval_helper` and set it's backing JSObject's "vector" to `butterfly`. ```javascript tgt.c = leakval_helper; // ... var butterfly = new int64(stale[2], stale[3]); tgt.c = leakval_u32; // ... stale[4] = butterfly.low; stale[5] = butterfly.hi; ``` Below is a snippet of how butterflies are structured, this was taken from the Phrack paper "Attacking Javascript Engines": ``` -------------------------------------------------------- .. | propY | propX | length | elem0 | elem1 | elem2 | .. -------------------------------------------------------- ^ | +---------------+ | +-------------+ | Some Object | +-------------+ ``` Notice how elem0 is accessible by accessing index 0 due to where the object references the butterfly. This is why using `leakval_u32` to set the `master` vector to `slave` works, because `slave` is at the zero-index. This means that the variable `butterfly` and `leakval_helper[0]` will be equivalent. If we place a JSValue in `leakval_helper[0]`, we can retrieve it's address by using our read() primitive on `butterfly`. Similarily, we can create a JSValue by writing it to the `butterfly`, and retrieving it via `leakval_helper[0]`. This allows us to convert bytes to JSValues and JSValues to bytes. ```javascript var prim = { // ... read/write primitives leakval: function(jsval) { leakval_helper[0] = jsval; var rtv = this.read8(butterfly); this.write8(butterfly, new int64(0x41414141, 0xffffffff)); return rtv; } createval: function(jsval) { this.write8(butterfly, jsval); var rt = leakval_helper[0]; this.write8(butterfly, new int64(0x41414141, 0xffffffff)); return rt; } } ``` # Stage 6: Code Execution (ROP) ## Introduction Due to NX and lack of permissions for JiT memory, we have to run our kernel exploit in a ROP chain. This section mostly covers how ROP chains work for those who are newer to exploitation, but also focuses on some of the specifics of how the chain is launched. The idea of a ROP chain is simple. If we cannot write our own instructions and execute them, we can write instruction sequences using snippets of code that are already available to us from the program to accomplish a similar goal (these are often called "gadgets"). This concept is often referred to as a "code re-use" attack, or more commonly "return-oriented programming", which is abbreviated to "ROP" for brevity's sake. The idea is we control the instruction pointer and make it jump from 1 gadget to another to another. To do this, each gadget must end with a `0xC3` opcode, which in x86/x86_64 is a "ret" instruction. Gadgets can also end with "jmp" instructions, but these are not typically used because not only are gadgets much more limited, but "jmp"'s cannot always be controlled by the attacker. ## Faking a Stack So how do we create a chain to put our instruction sequences in? We can create a fake stack and ensure the pointer to our fake stack finds it's way into the `RSP` (stack pointer) register. When the next `ret` instruction is hit, our fake stack will be used. This is called a "stack pivot", an optimal stack pivot allows you to set both `RSP` and `RIP` (instruction pointer) registers. First we should create a set of functions that allows us to easily create and manage ROP chains. This function will have methods such as "push" and "syscall" to push the necessary information on the stack to do the action specified. Technically we could do these all manually every time we want to initiate a syscall, but this is unmanagable and creating a class of functions to manage this makes a lot more sense. We'll also want to allocate the backing memory of the stack, a Uint32Array is a good candidate for this. We want to also create a pointer that points to the base of the fake stack, like an `RBP` register. Naturally we'll need to set this to the address of the Uint32Array in memory. Thankfully due to the primitives we setup earlier, leaking the address of this array is trivial, as we can leak the Uint32Array's backing JSArrayBufferView and dereference the address at offset 0x10. The `count` variable will act as `RSP`, and will keep track of where we are in the stack. ```javascript window.RopChain = function () { this.ropframe = new Uint32Array(0x10000); this.ropframeptr = p.read8(p.leakval(this.ropframe).add32(0x10)); this.count = 0; // ... } ``` The ability to reset the ROP chain will also be helpful. After every run of the ROP chain, we can reset the count and zero the backing memory to ensure the next chain runs without issue. ```javascript this.clear = function() { this.count = 0; this.runtime = undefined; for (var i = 0; i < 0xff0/2; i++) { p.write8(this.ropframeptr.add32(i*8), 0); } }; ``` We will also want the ability to easily push values or gadgets into the ROP chain. These functions will not only write these values into the ROP chain, but will also implicitly keep track of `count` to prevent corrupting the stack. ```javascript this.pushSymbolic = function() { this.count++; return this.count-1; } this.finalizeSymbolic = function(idx, val) { p.write8(this.ropframeptr.add32(idx*8), val); } this.push = function(val) { this.finalizeSymbolic(this.pushSymbolic(), val); } this.push_write8 = function(where, what) { this.push(gadgets["pop rdi"]); // pop rdi this.push(where); // where this.push(gadgets["pop rsi"]); // pop rsi this.push(what); // what this.push(gadgets["mov [rdi], rsi"]); // perform write } ``` Finally, we want a function that can allow us to easily call functions by address. This function is fairly trivial, it essentially just sets up the argument registers and pushes the function pointer on the stack. In x86_64 ABI, the following arguments correspond to the following registers: ``` Argument 1 = RDI Argument 2 = RSI Argument 3 = RDX Argument 4 = RCX Argument 5 = R8 Argument 6 = R9 ``` To save space on our fake stack, the `fcall` function we create will only push instructions for setting up registers that we actually define. We will also be calling system calls through `fcall`. Because Sony no longer allows us to call system call 0 to specify the call number, we'll call the syscall wrappers provided to us from `libkernel_web.sprx`. ```javascript this.fcall = function (rip, rdi, rsi, rdx, rcx, r8, r9) { if (rdi != undefined) { this.push(gadgets["pop rdi"]); // pop rdi this.push(rdi); // what } if (rsi != undefined) { this.push(gadgets["pop rsi"]); // pop rsi this.push(rsi); // what } if (rdx != undefined) { this.push(gadgets["pop rdx"]); // pop rdx this.push(rdx); // what } if (rcx != undefined) { this.push(gadgets["pop rcx"]); // pop r10 this.push(rcx); // what } if (r8 != undefined) { this.push(gadgets["pop r8"]); // pop r8 this.push(r8); // what } if (r9 != undefined) { this.push(gadgets["pop r9"]); // pop r9 this.push(r9); // what } this.push(rip); // jmp return this; } ``` ## Stack Pivotting So we've setup a fake stack, but how do we actually make our chain run? This is accomplished by the fairly complex function `p.loadchain()`. For the sake of brevity, I won't cover all of what the function does as much of it is context saving stuff. I will not go as in-depth in this portion as I did the core of the exploit, but I will cover it briefly. Since we have a `leakval` primitive to leak JSValues, we can easily use this to leak function pointers. Functions in JavaScript are represented by objects, and the function's pointer is located at offset 0x18. We can then add 0x40 to this dereferenced value to skip the header. ```javascript p.leakfunc = function(func) { var fptr_store = p.leakval(func); return (p.read8(fptr_store.add32(0x18))).add32(0x40); } ``` Now that we have a primitive to leak JS function pointers, we can choose a target function and overwrite it's function pointer to jump to where we please. Since we used parseFloat() earlier for defeating ASLR, we can use it again. We first want to save register context, we can do this using the `setjmp()` funcion in libc. This however requires us to set rdi as well, so we'll call a "jop" sequence to get there. ``` // JOP 0: 48 8b 7f 48 mov rdi,QWORD PTR [rdi+0x48] 4: 48 8b 07 mov rax,QWORD PTR [rdi] 7: 48 8b 40 30 mov rax,QWORD PTR [rax+0x30] b: ff e0 jmp rax ``` The `reenter_help` function is then called via `Array.prototype.splice.apply(reenter_help);` to perform the stack pivot. The stack pivot is performed by leaking the address of the fake stack's pointer and popping it into the rsp register. ```javascript var reenter_help = {length: {valueOf: function(){ orig_reenter_rip = p.read8(stackPointer); stackCookie = p.read8(stackPointer.add32(8)); var returnToFrame = stackPointer; var ocnt = chain.count; chain.push_write8(stackPointer, orig_reenter_rip); chain.push_write8(stackPointer.add32(8), stackCookie); if (chain.runtime) returnToFrame=chain.runtime(stackPointer); chain.push(gadgets["pop rsp"]); // pop rsp chain.push(returnToFrame); // -> back to the trap life chain.count = ocnt; p.write8(stackPointer, (gadgets["pop rsp"])); // pop rsp p.write8(stackPointer.add32(8), chain.stackBase); // -> rop frame }}}; ``` ## Function Calling Earlier we established a function called `fcall` in our ROP chain primitive to pop values into registers defined by the AMD64 ABI and push the function pointer on the stack to initiate a call. We will now create a wrapper that calls this function, but also additionally allows us to retrieve the return value. As defined in the ABI, returned values are always stored in the `rax` register, so by moving it into a memory address in our address space, we can easily retrieve it using our read primitive. ```javascript p.fcall = function(rip, rdi, rsi, rdx, rcx, r8, r9) { chain.clear(); chain.notimes = this.next_notime; this.next_notime = 1; chain.fcall(rip, rdi, rsi, rdx, rcx, r8, r9); chain.push(window.gadgets["pop rdi"]); // pop rdi chain.push(chain.stackBase.add32(0x3ff8)); // where chain.push(window.gadgets["mov [rdi], rax"]); // rdi = rax chain.push(window.gadgets["pop rax"]); // pop rax chain.push(p.leakval(0x41414242)); // where if (chain.run().low != 0x41414242) throw new Error("unexpected rop behaviour"); return p.read8(chain.stackBase.add32(0x3ff8)); } ``` ## System Calls As mentioned earlier, we cannot directly issue `syscall` instructions anymore in our ROP chains. We can however, call the wrappers provided to us to access them via the `libkernel_web.sprx` module. We can dynamically resolve syscall wrappers by reading the bytes to see if they match the structure of a syscall wrapper. This is far better compared to the past when we would have to reverse the libkernel module and add offsets manually for the system calls we needed, now we just need to keep a list of the syscall names if we want to call them by name. This list is kept in `syscalls.js`. ```javascript // Dynamically resolve syscall wrappers from libkernel var kview = new Uint8Array(0x1000); var kstr = p.leakval(kview).add32(0x10); var orig_kview_buf = p.read8(kstr); p.write8(kstr, window.moduleBaseLibKernel); p.write4(kstr.add32(8), 0x40000); var countbytes; for (var i=0; i < 0x40000; i++) { if (kview[i] == 0x72 && kview[i+1] == 0x64 && kview[i+2] == 0x6c && kview[i+3] == 0x6f && kview[i+4] == 0x63) { countbytes = i; break; } } p.write4(kstr.add32(8), countbytes + 32); var dview32 = new Uint32Array(1); var dview8 = new Uint8Array(dview32.buffer); for (var i=0; i < countbytes; i++) { if (kview[i] == 0x48 && kview[i+1] == 0xc7 && kview[i+2] == 0xc0 && kview[i+7] == 0x49 && kview[i+8] == 0x89 && kview[i+9] == 0xca && kview[i+10] == 0x0f && kview[i+11] == 0x05) { dview8[0] = kview[i+3]; dview8[1] = kview[i+4]; dview8[2] = kview[i+5]; dview8[3] = kview[i+6]; var syscallno = dview32[0]; window.syscalls[syscallno] = window.moduleBaseLibKernel.add32(i); } } ``` Our system call primitive wrapper will simply locate the offset for a given system call by the `window.syscalls` array and issue an `fcall` to it. ```javascript p.syscall = function(sysc, rdi, rsi, rdx, rcx, r8, r9) { if (typeof sysc == "string") { sysc = window.syscallnames[sysc]; } if (typeof sysc != "number") { throw new Error("invalid syscall"); } var off = window.syscalls[sysc]; if (off == undefined) { throw new Error("invalid syscall"); } return p.fcall(off, rdi, rsi, rdx, rcx, r8, r9); } ``` # Conclusion For a seasoned webkit attacker, this bug is trivial to exploit. For non-seasoned ones such as myself however, working with WebKit to leverage a read/write primitive from WebCore heap corruption can be confusing and challenging. I hope through this write-up that it can help other researchers new to webkit to understand a bit of the magic that happens behind webkit exploitation, as without understanding fundamental data structures such as JSObjects and JSValues, it can be difficult to make sense of what's happening. This is why I focused the core of the write-up on going from heap corruption to obtaining a read/write primitive, and how type confusion with internal objects can be used to achieve it. In the next section (yet to be published), we will cover the kernel exploit portion of the 4.55 jailbreak chain. While this WebKit exploit will work on 5.02 and lower, the kernel exploit will only work on firmware 4.55 and lower. # Credits [qwertyoruiopz]() Lokihardt # References [Chromium Bug #169685]() reported by lokihardt@google.com [Attacking Javascript Engines]() by sealo [Technical Analysis of the Pegasus Exploits on iOS]() by Lookout | https://www.exploit-db.com/exploits/44230 | CC-MAIN-2020-34 | en | refinedweb |
Developing a Command Parser-Based ZenPack
Note: Thanks to David Petzel for writing this excellent tutorial!
Contents
- 1 Inspiration
- 2 Conventions and Assumptions
- 3 Let's Get To It
- 4 Pulling It All Together
Inspiration
I still consider myself a relative newb with Zenoss as well as Python development. A while back I set out to write a custom ZenPack for use with F5 LTMs. I never would have been able to figure this out without the assistance of a great guide written by Jane Curry. Her outstanding document can be found on the Zenoss community site:
I recently had a need for a ZenPack to interact with a couple of Varnish 3.x servers. I scoured the net of course hoping someone had already done the work for me, but no such luck. I did come across a few solutions for 2.x, but from what I've been able to gather the interface to get these stats has changed some (no more fetching stats over the management port). So I set out to write my own.
I of course cracked Jane's document open, but I quickly realized that it was very SNMP-centric. This was perfect for the F5 pack as the device supports SNMP. However, in this case SNMP is not an option. I've done enough research to know that what I wanted to do is a custom Command Parser. The good news is that most of the concepts from Jane's doc still applied, the bad news is that the mechanics were going to be very different.
I searched around a bit and I was able to find a few other ZenPacks that had taken this approach, but I couldn't find any "how-to" style documentation. As I mentioned before I don't consider myself a seasoned Python developer so for me reverse-engineering someone's else's ZenPack would be a challenge. There is a small snippet of information in the Zenoss Developer's Guide, but its far from a walk-through or step-by-step guide like Jane's document.
So I came to the sad realization that the approach was going to have to be looking at what others had already done. So I figured I should probably document the process and make it available to others in case they find themselves in a similar situation.
Conventions and Assumptions
Throughout this document I hope to link to existing documentation where it exists so for things that are already covered elsewhere I will try and link to them, rather than recreate similar documentation.
Nearly everything done from the command line on a Zenoss server should be done while logged in as the Zenoss user (as opposed to root). Whenever I say as the zenoss user that means:
$ ssh root@your_zenoss_server # su - zenoss
When it comes to breaking down code, I'm going to try and display the minimal amount of code to make my point. Some of the files might have alot of extra code that has nothing to do with the effort of writing a command parser. An example of this would be all of the code needed to parse the output of varnishstat. The mechanics of parsing the data and how its laid out is not within the scope of this document. It's more important that we identify how we get to the point of being able to parse the output, as well as how to take the parsed output and use it to graph data. Since all the files we talk about are open source and part of the ZenPack, it would be redundant to fully copy the contents of files into this guide.
Let's Get To It
Create Your Empty ZenPack Shell
Creating an empty ZenPack is covered in numerous locations so I won't dive into the details here. If you don't know how to create an empty shell, refer to section 3.2 of the Zenoss Developer's Guide. Additionally Jane's Creating Zenoss ZenPacks for Zenoss 3 covers it in section 2.1. In this case we will be creating ZenPacks.community.Varnish3.
Once the empty shell is created, you will certainly want to move it out of the main ZenPack directory and into a seperate folder which we will put under source control. My Zenoss development instance is running on a Virtual Box VM and I store the files in a shared folder. This is personal preference, feel free to put the files anywhere you want, just remember that every time I reference '/media/zenpack_git_sources/ZenPacks.community.Varnish3/' you should replace that with whatever folder you copied your pack out to. Here is what I ran as the zenoss user:
$ cp -R $ZENHOME/ZenPacks/ZenPacks.community.Varnish3 /media/zenpack_git_sources/ZenPacks.community.Varnish3 $ zenpack --link --install=/media/zenpack_git_sources/ZenPacks.community.Varnish3 $ zenoss restart
The full restart is arguably overkill, but I find knowing which situations require restarting which daemons to be inconsistent so while it takes longer, I usually just do a full restart rather than pick and choose which daemons to restart.
Initialize a new GIT Repo in your ZenPack Folder
As Zenoss seems to be making the move to GitHub as outlined in ZenPack Development Process we are going to cooperate with that effort :) The ZenPack Development Process document does a good job already of providing both abbreviated as well as in-depth explanation of the process. For me I've got the GIT client on my Zenoss VM, rather than my host PC, but since we are using shared folders it should work equally well from either. Here is what I ran as the zenoss user to initialize the new repo:
$ cd /media/zenpack_git_sources/ZenPacks.community.Varnish3 $ git init
If this is the first time using git under the zenoss user login you probably need to setup your user name and email:
$ git config --global user.name "Firstname Lastname" $ git config --global user.email "your_email@youremail.com"
Next I grabbed the 'master' .gitignore file. Still as the zenoss user:
$ cd /media/zenpack_git_sources/ZenPacks.community.Varnish3 $ wget
Additionally I use Eclipse with the pydev module on my PC as my IDE. As a result there are a couple of extra files we will want to add to the .gitignore file. If you use some other IDE (or none at all) you can skip the following lines. Still as the zenoss user:
$ cd /media/zenpack_git_sources/ZenPacks.community.Varnish3 $ echo .pydevproject >> .gitignore $ echo .project >> .gitignore
Now add everything and do a commit. You should note that this commit does not push anything up to GitHub, it simply commits the files into your local repo. Once again, run the following as the zenoss user:
$ git add -A $ git status $ git commit -m 'Commiting the initial empty shell'
At this point we've done the following:
- Created the empty ZenPack shell
- We've relocated it outside of Zenoss installation directory
- We've initialized a new local GIT repository
- Added a few IDE specific files that should be ignored from source control
- Committed everything.
Now comes the fun part... figuring out how to actually write this crazy thing:)
Identifying The Pieces
Before we get too far, its important to understand what items we want to include in this ZenPack. This is where it starts to get dicey if you don't know some of the inner workings of Zenoss. I'll do my best to explain or link to other documentation on each item.
Monitoring Template
Monitoring Templates, also called RRD Templates, are the real meat to getting your performance data displayed. We will be creating one monitoring template. This template will be used to trend various performance metrics.
Command Parser
The whole reason for this document...... We'll be running the varnishstat command over SSH and parsing the output to get all the data to graph. The Zenoss Developer's Guide talks about this in section 12.5.2. Its not very newb friendly so thats where I hope to bridge the gap.
Building The Pieces
The Command Parser
Lets create the file that will hold our new command parser:
$ mkdir /media/zenpack_git_sources/ZenPacks.community.Varnish3/ZenPacks/community/Varnish3/parsers $ touch /media/zenpack_git_sources/ZenPacks.community.Varnish3/ZenPacks/community/Varnish3/parsers/VarnishStat.py
The contents of my VarnishStat.py contain a good bit more than what I am showing below, however most of the code in that file is used for the actual parsing of the varnishstat output and has nothing to do with creating a command parser. The number of items actually required in the command parser is actually much smaller than I thought would be required when I started out.
First we start with the necessary imports. There is really only one required:
from Products.ZenRRD.CommandParser import CommandParser
Setup logging. This is technically not required, but Python makes logging so easy its really a crime to not use it:
import logging logger = logging.getLogger('.'.join(['zen', __name__]))
The "logger =" line warrants a little explanation. The Python logging module works some magic with name spaces so an application (in this case ZenCommand) can decide on a logging namespace. In this case Zenoss uses the zen.* name space. This means any loggers we create that start with "zen." will automatically inherit the logging settings already defined by ZenCommand helping us to ensure a consistent look and feel. The "__name__" piece simply appends the module name onto the logger name. I like to do this so it is crystal clear what module a log entry came from.
Next we need to create our new command parser class as such:
class VarnishStat(CommandParser):
One thing I found the hardware way is that it appears Zenoss makes some assumptions that the class name match the module name (including case). So as you can see in this example we've created class VarnishStat inside of file VarnishStat.py. Notice the matching names and case. Additionally the class should extend the CommandParser class we imported above.
Now we need to define our single required method:
def processResults(self, cmd, result):
On the surface it looks simple enough, but there is actually alot of magic going on here. First the method has to be called processResults. Additionally it should accept cmd and result as input paramaters. The two input parameters which are passed automatically by ZenCommand when it invokes your processResults method are the keys to success here. I'll do my best to describe the important parts (that I am aware of).
cmd is an instance of the Products.ZenRRD.zencommand.Cmd object.
- cmd.command: This will contain the command line that was executed. This is useful if you have a command line that might change, or if you need to validate that proper flags were used.
cmd.points: This is a list of the datapoints being requested from your monitoring template. This one took me a few minutes to get my head around so I'll go into a bit of detail. I'll show you a visual when we talk about the monitoring template, but for now. Assume our monitoring template is named Varnish3 and our datasource is named Varnish3Stats . We will have only one datasource, but we will have multiple datapoints (one for each stat). Lets say we defined two datapoints named cache_hit and cache_miss.
When our processResults is invoked cmd.points will contain two Datapoint objects. If printed they look like: [({}, 'cache_hit'), ({}, 'cache_miss')] Its important to understand that these are Datapoint objects, and not simply strings representing the names of the Datapoints.
cmd.result: Is an object instance which contains additional information about the results of the executed command.
cmd.result.output: This is the text that was returned from the invoked command. This is what you want to parse.
cmd.result.exitCode: This the return code from the invoked command. There is a good chance you want to levarage this and only attempting parsing on a valid return code.
results is a ParsedResults object which at the time your method is called contains two empty lists: events and values. These will be populated by your processResults method. The results object is discussed a bit in section 12.5.2 of the Zenoss Developer's Guide
result.events: This is a list which will have the end result of creating events which will show up in the event console. As you may or may not use them, I'm not going to go into alot of detail, but you can see an example usage in the _errors_found method of the VarnishStat parser.
result.values: This is the list you'll use to return values for each datapoint which will end up in the actual RRD files. This ends up being a list of tuples, where each tuple is a datapoint, value pairing. In this context the datapoint is the actual datapoint object, and not the string representation of the datapoint name. A very contrived example of this would look like:
for dp in cmd.points: result.values.append((dp, 12345))
This example is fairly stupid but it illustrates the concept. If you recall the earlier contents of cmd.points, this would end up assigning the value "12345" to the cache_hit as well as cache_miss datapoints.
In the real world "12345" would be replaced with the value of the actual datapoint and not a static value. You can see this in action toward the tail end of the processResults method in the VarnishStat parser.
So the simpliest, working version of the parser could look like this:
from Products.ZenRRD.CommandParser import CommandParser class VarnishStat(CommandParser): def processResults(self, cmd, result): #Do Some Parsing Code #.... for dp in cmd.points: result.values.append((dp, 12345)
Obviously you'll want to fill in the parsing code section with real code and add error checking, but that minimal amount of code could actually do the trick
The Monitoring Template
At this point we've got the bare essentials around the command parser. The second half to making this all work is creating the monitoring template.
- Start by logging into your Zenoss server UI and navigate to Monitoring Templates section of the GUI: ''
Next hit the '+' icon in the lower left corner of your screen. This will open the Add Template dialogue box. Give your template a name, I called mine Varnish3. Next decide which device class to target. I'd suggest targeting the highest level device class that the software you are parsing could run on. As an example I'm targeting Varnish3 at /Server/Linux.
Now you have an empty template. Click the '+' icon right under where it says 'Data Sources'. This is not the same '+' you just clicked. This will open the 'Add Data Source' dialogue window.
- Enter the name for your datasource, in my case it was Varnish3Stats.
- Ensure you select a type of COMMAND*
|
You will now see your new datasource listed in the 'Data Sources' column. Double click the newly created data source to enter 'Edit Data Source' dialogue window. There are two critical things to complete in this window
- First, you need to be certain you select the new parser you just created. In my case this is ZenPacks.community.Varnish3.parsers.Varnish3Stat
- Second, you want to populate the 'Command Template' field with the actual command you want to run. Its worth mentioning again, this is the actual command that will get executed. In this case its /usr/bin/varnishstat -x
- One more option to consider is the 'Use SSH' checkbox. Depending on where you intend the command to be run, you may or may not want to enable this. In my case I want the varnishstat command to be executed on the remote host, so I need to enable that option
Once that is saved you will want to hit the small gear icon just about your newly created datasource and select 'Add Data Point'. The name you enter should exactly match the name of the stat you want to collect. Repeat this step for each stat you want to collect. Going back to our earlier example we would add one datapoint named cache_hit and a second datapoint named cache_miss. If you recall, these datapoints you are creating here are what is passed as cmd.points to your processResults method.There is quite a bit to understand about datapoints which are outside the scope of this document. At a high level you should understand what the different types of datapoints do, and when one type is appropriate over another. Be sure to review section 6.2 of the Zenoss Administration guide as it goes into good details about datapoint types.
You will also want to setup Graph Definitions at this time. This is another topic that is covered in section 6.2.8 of the Zenoss Administration guide so I won't re-hash it. Here is sample of what my completed template looks like:
Once you have everything to your liking, we need to add this template to the ZenPack so it gets exported along with the command parser code we wrote. Using the gear menu in the lower left of your screen, select 'Add to ZenPack'. You will be prompted with a list of ZenPacks that are currently in development mode (allowing updates). Select the ZenPack you created earlier in this document. In my case that is ZenPacks.community.Varnish3.
Pulling It All Together
So at this point you have a working command parser. This command parser is referenced by your new super-cool monitoring template and life is good. At this point you could bind your monitoring template to a device or device class and assuming you've got things configured correctly, begin collecting the metrics you've defined in your monitoring template.
However, your command parser and template are probably too cool to keep to yourself so you should really share it with the rest of the Zenoss community. At this point you need to export your ZenPack. This will result in all your custom code and template(s) being pulled together into a single redistributable file commonly referred to as an "EGG" file. The EGG file is what users (who are not interested in the source code) will download and install into their own Zenoss installations.
Follow the section 'Install and Test ZenPack in Zenoss' in ZenPack Development Process to export your EGG and get your new ZenPack uploaded to GitHub.
Thats IT!!!. I know there is a lot of information we only briefly touched on but the reality is Zenoss is a complex beast. No single document can give you all the information you need, but my hope is that this document is enough information for those that are familiar with Zenoss to get started writing a custom command parser. | http://wiki.zenoss.org/Developing_a_Command_Parser-Based_ZenPack | CC-MAIN-2020-34 | en | refinedweb |
Knowledge of JavaScript / ES6+ is important if you want to build React applications. Indeed, ES6+ brings a lot of cool stuff to JavaScript that makes writing React components much easier and cleaner.
While ES6 and its following updates came with many new features, there are a couple of concepts that you really need to know in order to write better and cleaner React apps. Mastering those concepts will make you a better JavaScript developer and brings your React applications to the next level.
Hence, I've decided to create this post in order to share with you the 10 most useful JavaScript / ES6+ concepts that you need to master to become a better React developer..
As you may know, the simplest way to define a React component is to write a JavaScript function like in the following example.
function MyComponent(props) { return <h1>Hello from AlterClass.io</h1>; }
But there’s another very simple and concise way for creating React function components, that’s even better than regular functions. It’s called
arrow functions.
const MyComponent = (props) => <h1>Hello from AlterClass.io</h1>;
As you can see, it allows us to write less code to achieve the same result.
Arrow functions are what you’ll see the most in JavaScript and React applications. So, it is a good idea to understand and master them.
Before diving into how they are used in React, let's see how to write them. Indeed, there are a variety of syntaxes available to write an arrow function. We’ll cover the common ones here to get you up and running.
// Basic syntax with multiple parameters const add = (a, b) => { return a + b }; // Curly brackets aren’t required if only one expression is present // The `return` keyword is also implicit and can be ommited const add = (a, b) => a + b; // Parentheses are optional when only one parameter is present const getUser = data => data.user; // However, parentheses are required when no parameters are present const hello = () => console.log("Hello from AlterClass.io");
Now that we’ve covered the basic syntaxes, let’s get into how arrow functions are used with React. Apart from defining React components as above, arrow functions are also really useful when manipulating arrays, and when working with asynchronous callbacks and Promises.
Indeed, in React we usually have to fetch data from a server and display it to our users. To retrieve this data we often use and chain Promises.
// ES5 fetch(apiURL) .then(function(res) { return res.json(); }) .then(function(data) { return data.products; }) .catch(function(error) { console.log(error); });
Promises chaining is simplified, easier to read, and it is more concise with arrow functions:
// ES6 fetch(apiURL) .then(res => res.json()) .then(data => data.products) .catch(error => console.log(error));
Finally, once we have retrieved our data we need to display it. To render a list of data in React, we have to loop inside JSX. This is commonly achieved using the map/reduce/filter array methods.
const products = [ { _id: 1234, name: "ReactJS Pro Package", price: 199 }, { _id: 5678, name: "ReactJS Basic Package", price: 99 }, ... ];
// ES5 function ProductList(props) { return ( <ul> {props.products .filter(function(product) { return product.price <= 99; }) .map(function(product) { return <li key={product._id}>{product.name}</li>; })} </ul> ); }
Now, let's see how to achieve the same thing with ES6 arrow functions.
// ES6 const ProductList = props => ( <ul> {props.products .filter(product => product.price <= 99) .map(product => ( <li key={product._id}>{product.name}</li> ))} </ul> );
Now that we've seen what are arrow functions, let's talk about default parameters. This ES6+ feature is the ability to initialize functions with default values even if the function call doesn’t include the corresponding parameters.
But first, do you remember how we use to check for undeclared parameters in our functions before ES6? You may have probably seen or used something like this:
// ES5 function getItems(url, offset, limit, orderBy) { offset = (typeof offset !== 'undefined') ? offset : 0; limit = (typeof limit !== 'undefined') ? limit : 10; orderBy = (typeof orderBy !== 'undefined') ? orderBy : 'date'; ... }
To prevent our functions from crashing, or to compute invalid/wrong results, we had to write extra code to test each optional parameter and assigned default values. Indeed, this technique was used to avoid undesired effects inside our functions. Without it, any uninitiated parameters would default to a value of
undefined.
So, that’s a brief summary of how we handled default parameters prior to ES6. Defining default parameters in ES6 is much easier.
// ES6 function getItems(url, offset = 0, limit = 10, orderBy = 'date') { ... } // Default parameters are also supported with arrow functions const getItems = (url, offset = 0, limit = 10, orderBy = 'date') => { ... }
Simple and clean 👌. If offset, limit, and orderBy are passed into the function call, their values will override the ones define as default parameters in the function definition. No extra code needed.
⚠️Be aware that
nullis considered a valid value. This means that if you pass a
nullvalue for one of the arguments, it won't take the default value defined by the function. So make sure to use
undefinedinstead of
nullwhen you want the default value to be used.
Now you know how to use default parameters in ES6. What about default parameters and React?
In React, you have the ability to set default values to component props using the defaultProps property. However, this is only available for class components. Actually, the React team is making the
defaultProps property on function components deprecated and they will be removed it.
No worries! We can leverage default parameters to set default values to our React function component props. Check out below for an example.
const Button = ({ size = 'md', disabled = false, children }) => ( <button type="button" disabled={disabled} className={`btn-${size}`} > {children} </button> );
Template literals are strings allowing embedded JavaScript expressions. In other words, it is a way to output variables/expressions in a string.
In ES5 we had to break the string by using the
+ operator to concatenate several values.
// ES5 console.log("Something went wrong: " + error.message);
In ES6, template literals are enclosed by the backtick character instead of double or single quotes. To insert expressions inside those templates, we can use the new syntax
${expression}.
// ES6 console.log(`Something went wrong: ${error.message}`); ... console.log(`Hello, ${getUserName()}!`); ...
Template literals are making this kind of substitution more readable. Using them in React will help you set component prop values, or element attribute values, dynamically.
const Button = (props) => ( <button type="button" className={`btn-${props.size}`} > {props.children} </button> );
In ES5, the only way to declare variables was to use the
var keyword. ES6 introduced two new ways to do it with
const and
let. If you want to learn every detail about those guys, please have a look at this awesome post. Here, I'm just going to list the main differences:
var
- function scoped
- hold
undefinedwhen accessed a variable before it is declared
let
- block scoped
-
ReferenceErrorwhen accessed a variable before it's declared
const
- block scoped
-
ReferenceErrorwhen accessed a variable before it's declared
- can't be reassigned
- should be initialized when declared
Since the introduction of let and const, the rule of thumb is to use them instead of var. You should not use var anymore. Let and const are more specific and give us more predictable variables.
Also, prefer using const over let by default because it cannot be re-assigned or re-declared. Use let when you will need to re-assign the variable.
In a React application,
const is used to declare React components as they won't be reassigned. Other than that, variables that should be reassigned are declared with let, and variables that should not be reassigned are declared with const.
const OrderDetails = (props) => { const [totalAmount, setTotalAmount] = useState(0.0); const { state } = useContext(Context); useEffect(() => { let total = state.course.price; // substract promotional discount total -= state.course.price * state.course.discountRate; // add taxes total += total * state.course.taxPercentage; setTotalAmount(total); }, [state] ); const handleOnClick = () => { ... }; return ( <> <span>Total: ${totalAmount}</span> <button onClick={handleOnClick}>Pay</button> </> ); };
JavaScript classes were introduced with ES6. As stated by the MDN web documentation, classes are "primarily syntactical sugar over JavaScript's existing prototype-based inheritance". Although, there are some properties that are worth knowing as they are not quite the same as class written using regular functions. For that, check this great post.
// ES6 class definition class User { constructor(name) { this.name = name; } greet() { return `${this.name} says hello!`; } } // Usage let user = new User("Greg"); user.greet(); // --> Greg says hello!
An interesting concept related to classes is inheritance. This is not something specific to JavaScript but it is a common concept in object-oriented programming. In short, this is the ability to create a class as a child of another class. The child class will inherit from the properties of its parent (actually this is quite more complex than that depending on the OOP language that you are using).
In ES6, the
extends keyword is used to create a class based on another one.
class Employee extends User { constructor(name, salary) { // call the constructor of the User class super(name); // add a new property this.salary = salary; } raiseSalary() { this.salary += 10000; return this.salary; } } // Usage let employee = Employee("Greg", 250000); employee.raiseSalary(); // --> 260000
In React application, you can also use an ES6 class to define a component. To define a React component class, you need to extend the
React.Component base class as follow:
class Button extends React.Component { render() { return <button type="buttom">Click me</button>; } }
By creating components like this, you will have access to a bunch of methods and properties related to React components (state, props, lifecycle methods, ...). Have a look at the React documentation for a detailed API reference of the
React.Component class.
Destructuring is used very often in React. This is a concept that can be used with objects as well as arrays. Destructuring is an easy way to simplify our JavaScript code because it allows us to pull data out of an object or array in one single line.
Array destructuring is similar to object destructuring except that we pull data out one by one in the order they appear in the array.
Let's jump right into how it is used in a React application.
// grab `useState` with object destructuring import React, { useState } from 'react'; // grab individual props with object destructuring const Button = ({ size = 'md', disabled = false }) => { // grab stateful value and update function with array destructing const [loading, setLoading] = useState(false); return (...); };
The ternary operator is used as a shortcut for the
if statement. The syntax of a typical
if statement is the following:
if (condition) { // value if true } else { // value if false }
This is how it looks like using the ternary operator:
condition ? valueIfTrue : valueIfFalse
As you can see this is a much shorter way to define a conditional statement.
If the condition is truthy, the first statement is executed (before the colon
:). Otherwise, if the condition is falsy (false, null, NaN, 0, "", or undefined), the second statement is executed (after the colon
:).
However, this is not necessarily the cleanest or the more readable way to write conditions. So, be careful when using it as it can become a nightmare to understand, especially if you are chaining multiple conditions as follow.
return condition1 ? value1 : condition2 ? value2 : condition3 ? value3 : value4;
In React, the ternary operator allows us to write more succinct conditional statements in JSX. It is common to use it to decide which component to display or show/hide components based on conditions.
const App = () => { const [loading, setLoading] = useState(false); const [showPopup, setShowPopup] = useState(false); ... return ( <> <Navbar /> {loading ? <Spinner /> : <Body />} ... {showPopup && <Popup />} </> ); };
Prior to ES6, as they were no native modules support in JavaScript, we used libraries like RequiredJS or CommonJS to import/export modules. You may have probably seen that before, especially if you have already used Node.js.
// ES5 with CommonJS var express = require('express'); var router = express.Router(); router.get('/', function(req, res) { ... }); module.exports = router;
In ES6, we could natively use the
export and
import statements to handle modules in our applications.
// auth.js export const login = (email, password) => { ... }; export const register = (name, email, password) => { ... }; // main.js import { login, register } from './auth';
This is really useful in React as we are breaking the application UI into a component hierarchy. Components are defined in their own file and required in others such as in the following example:
// Button.js const Button = ({Submit</Button> </> );
You might be familiar with the concept of asynchronous programming. In JavaScript, they are quite some ways to work with asynchronous code (callbacks, promises, external libraries such as Q, bluebird, and deferred.js, ...). Here I'm going to talk about
async/await only.
Async/await is a special syntax to work with promises in a more comfortable fashion. It is really easy to understand and use.
In case you need to learn about promises, have a look at the MDN doc page.
As you may have noticed, there are two new keywords:
async and
await.
Let’s start with the async keyword first. Async is used to define an asynchronous function that returns an implicit Promise as its result.
async function myAsyncFunc() { return "Hello from AlterClass!"; } // Usage myAsyncFunc().then(...);
Note that the syntax and structure of code using async functions look like regular synchronous functions. Simple, right? But wait! There’s another keyword,
await.
The keyword await works only inside async function. It makes the program wait until the promise settles and returns its result. Here's an example with a promise that resolves after a few seconds:
async function myAsyncFunc() { let promise = new Promise((resolve, reject) => { setTimeout(() => resolve("Hello!"), 3000) }); let result = await promise; // wait until the promise resolves alert(result); // "Hello!" }
This is a much more elegant way of getting a promise result than using
promise.then(), plus it is easier to read and write.
⚠️Once again, be careful as await can not be used in regular functions. If you do it, you would get a syntax error.
One more thing which is worth mentioning with async/await is how to handle errors. Indeed, if a promise resolves normally, it returns the result. But in case of a rejection, it throws an error. You can either use the promise
catch method or
try..catch the same way as a regular throw, to handle rejections.
asynFunction().catch(error => console.log(error)); // or try { asynFunction(); } catch(error) { console.log(error) }
I have included async/await in this list because, in every front-end project, we are doing a lot of stuff that requires asynchronous code. One common example is when we want to fetch data via API calls.
In React, this is how we could do it using promises + async/await.
const App = () => { const [loading, setLoading] = useState(true); useEffect(() => { async function fetchData() { // Check if user is authenticated const user = await getUser(); // Stop loading spinner setLoading(false); }; fetchData().catch(alert); }, []); if (loading) { return <Spinner />; } return <>...</>; };
The spread operator and the rest parameter are represented by the three dots
.... In the case of the spread operator, it expands an iterable into individual elements. For the rest operator, it gathers the rest of the list of arguments into an array.
Let's see some examples to understand how they work and how to use them.
// Rest parameter function sum(...args) { let sum = 0; for (let i = 0; i < args.length; i++) { sum += args[i]; } return sum; } // Spreading elements on function calls let array = [10, 6, 4]; console.log(Math.max(...array)); // 10 // Copying an array let items = ['item1', 'item2', 'item3']; let newArray = [...items]; console.log(newArray); // ['item1', 'item2', 'item3'] // Concatenating arrays let array1 = ['1', '2', '3']; let array2 = ['A', 'B', 'C']; let result = [...array1, ...array2]; console.log(result); // ['1', '2', '3', 'A', 'B', 'C'] // Spread syntax for object literals var object1 = { _id: 123, name: 'Greg' } var object2 = { age: 28, country: 'FR'} const user = { ...object1, ...object2 } console.log(user); // { "_id": 123, "name": "Greg", "age": 28, "country": "FR" }
The spread operator is highly used in libraries such as Redux to dealing with application state in an immutable fashion. However, this is also commonly used with React to easily pass down all object's data as individual props. This is easier than passing down each prop one by one.
If you have heard about HOC (High-Order Component) before, you know that you need to pass down all the props to the wrapped component. The spread operator is helping with that.
const withStorage = (WrappedComponent) => { class WithStorageHOC extends React.Component { ... render() { return <WrappedComponent {...this.props} />; } } };
In this article, I introduced you to some great ES6+ features to build awesome React applications. Of course, there are many other JavaScript features that you could use, but those 10 are the ones I see and use the most in any React project.
If you liked this post, do not forget to bookmark it and share it with your friends. If you have any questions, feel free to comment below, and follow me for more upcoming posts!. | https://alterclass.hashnode.dev/10-javascript-concepts-you-should-learn-to-master-react-ck7np7c5c000d64s1t9ac213k?guid=none | CC-MAIN-2020-34 | en | refinedweb |
Xml
Text Reader Class
Definition
public ref class XmlTextReader : System::Xml::XmlReader, System::Xml::IXmlLineInfo, System::Xml::IXmlNamespaceResolver
public ref class XmlTextReader : System::Xml::XmlReader, System::Xml::IXmlLineInfo
public class XmlTextReader : System.Xml.XmlReader, System.Xml.IXmlLineInfo, System.Xml.IXmlNamespaceResolver
public class XmlTextReader : System.Xml.XmlReader, System.Xml.IXmlLineInfo
type XmlTextReader = class inherit XmlReader interface IXmlLineInfo interface IXmlNamespaceResolver
type XmlTextReader = class inherit XmlReader interface IXmlLineInfo
Public Class XmlTextReader Inherits XmlReader Implements IXmlLineInfo, IXmlNamespaceResolver
Public Class XmlTextReader Inherits XmlReader Implements IXmlLineInfo
- Inheritance
-
- Implements
-
Remarks
Note
Starting with the .NET Framework 2.0, we recommend that you create XmlReader instances by using the XmlReader.Create method to take advantage of new functionality.does not provide data validation.
Checks that
DocumentTypenodes are well-formed.
XmlTextReaderchecks the DTD for well-formedness, but does not validate using the DTD.
For nodes where NodeType is
XmlNodeType.EntityReference, a single empty
EntityReferencenode a validating.
Notes to Inheritors
This class has an inheritance demand. Full trust is required to inherit from
XmlTextReader. | https://docs.microsoft.com/en-au/dotnet/api/system.xml.xmltextreader?view=netframework-4.7.1 | CC-MAIN-2020-34 | en | refinedweb |
Apple’s App Store is the holy grail for mobile developers. With React Native you can develop native apps for Android and iOS using a single code-base but getting things ready for publishing can be tricky, especially if you are starting with an originally Android-only application.
Here you’ll be starting with the code from a previous monster Okta blog post designing and publishing a calculator-like app on the Android Play store, which includes authentication via Okta.
For this post, you’ll first get the Android app to work well on iOS, as well as adding a splash screen and app icon. Then you’ll go through the signing process and publishing onto the App Store.
Start by cloning the repo and installing all the required libraries.
git clone cd okta-react-native-prime-components-example npm install
From here you should be able to say
react-native run-android to deploy to an emulator or attached Android phone. Everything should work fine.
Configure Authentication for Your React Native iOS App
Right now when you click Login you will be taken to an Okta login page. This is connected to an Okta account I used for development. You need to create your own account and configure this app to use it.
First, sign up for a free Okta developer account, or log in if you already have one. Then navigate to Applications > Add Application. Select Native and click Next. Choose a name and click Done. Note your Login redirect URI and the Client ID since you have to add them to your app.
Now in your
App.js find where the config variable is defined (near the top) and change the pertinent values to that of your Okta app:
const config = { issuer: 'https://{yourOktaDomain}/oauth2/default', clientId: '{clientId}', redirectUrl: '{redirectUrl}', additionalParameters: {}, scopes: ['openid', 'profile', 'email', 'offline_access'] };
Running Your React Native App on iOS Simulator
Start by running
react-native run-ios from a Mac computer. An iOS simulator should appear and in the console, your project will compile.
NOTE: If you get an error
Print: Entry, ":CFBundleIdentifier", Does Not Exist there are several issues on Github tracking this with various suggestions on fixing it. The simplest might just to open up
ios/prime_components.xcodeproj in Xcode and build the project from there.
You should see an error
'AppAuth/AppAuth.h' file not found. You need to link the AppAuth library to iOS. The easiest is with Cocoapods. Put the following into
ios/Podfile:
platform :ios, '11.0' target 'prime_components' do pod 'AppAuth', '>= 0.94' end
After having installed Cocoapods change into
ios/ and run
pod install. This will take a while. Now close Xcode and open
ios/prime_components.xcworkspace (note: the workspace, not the project!) in Xcode. The pods should appear as a separate project. Select a device and the project should build and run just fine (just click the play button). You may have to change the bundle identifier if the one used in this tutorial is already taken.
At this point, the factorization should work but if you click Login it will crash because your AppDelegate class needs to conform to
RNAppAuthAuthorizationFlowManager. Open
AppDelegate.h and change it to the following:
#import <UIKit/UIKit.h> #import "RNAppAuthAuthorizationFlowManager.h" @interface AppDelegate : UIResponder <UIApplicationDelegate, RNAppAuthAuthorizationFlowManager> @property (nonatomic, weak) id<RNAppAuthAuthorizationFlowManagerDelegate>authorizationFlowManagerDelegate; @property (nonatomic, strong) UIWindow *window; @end
Now the login button should take you through the authorization process.
Adjust Styling in Your React Native iOS App
When I ran the app, the font was a bit large and the banner looked like it was showing the background behind the app. To fix these:
- In
components/Button.jschange the font size to 25
- In
components/Header.jschange the font size to 65
- In
components/Input.jschange the flex to 1.5 and the font size to 60
The transparency issue in the header is from the iOS status bar showing. To hide this import
StatusBar from
react-native in
App.js and add
<StatusBar hidden /> at the top of the container:
return ( <Container> <StatusBar hidden />
The app should look correct now.
Set the Icon and Display Name and Run on a Device
As in the previous post, you can use an app like Iconic to create an icon (though that one is for Android). Once you have an icon you can use an online service like MacAppIcon to get all the sizes you need. Then in Xcode open the
prime_components project and click on
Images.xcassets. You will see all the icons you need to fill it - simply drag them the correct sizes from Finder.
You will also want to change the display name of your project to fix the app name on your device. This is in the Identity section of the project settings.
Make sure you have set up the signing team and also that the Build Active Architectures Only is set to Yes for both debug and release, for both projects - This can fix a lot of integration problems with the AppAuth library.
Once done, you should be able to deploy to a device and see a proper icon and name for your app.
Create a Splash Screen for Your React Native iOS App
iOS apps have splash screens while they load. React Native creates a basic
LaunchScreen.dib image which is just a white screen with the app’s name.
The easiest way to change this is by using the React Native Toolbox.
- Create a square image of at least 2208x2208 pixels
- Make sure to have plenty of margin around your symbol
For example:
A good image manipulation program to use is GIMP.
Next, install the toolbox as well as ImageMagick:
npm install -g yo@2.0.5 generator-rn-toolbox@3.8.0 brew install imagemagick
Now place your image inside of your project, close the workspace inside of XCode and run the following command:
yo rn-toolbox:assets --splash image.png --ios
Make sure to specify the correct project name! (In this case it is prime_components and not
prime-components). The images should be generated and your project updated. Uninstall your app from the simulator/device and re-deploy from Xcode and you should see the new splash when loading the app.
Submit Your React Native App to the iOS Store
What follows are instructions on submitting your app to the App Store but since the Prime Components app already exists this is for those who have another app they’d like to submit. In that case, follow the instructions from the previous blog post (linked above) on how to design and build your own app before continuing here.
Review Guidelines
Before you begin it’s worth reading through Apple’s App Store Review Guidelines. In plain English, it explains what you need to make sure your app is ready (and why the app might be rejected during review). Things like safety and performance are covered, as well as business practices like advertising. A lot of it is very sensible.
App Store Connect
To get started login to App Store Connect and accept the terms and conditions. Then click on the My Apps icon.
Click on the plus sign and select New App. Fill in the required values. Here the Bundle ID is the bundle identifier you set in your project settings. It’s important this is a unique value - good practice is to start with a website you own like com.myblog.my_app. You can’t change this once you’ve submitted a build.
Once everything is filled in you will get to the app management page with three tabs for the App Store section: App Information, Pricing and Availability, and the iOS submission page.
Fill out everything as best you can. Any missing information will come out when you try to submit your app for review. Set the pricing to free, and the availability to all territories. Select two categories for your app in App Information. This is for people who are browsing for new apps.
Because you are not charging for your app and there is no advertising a lot of this process will go smoothly.
Build an Archive
iOS apps are distributed with archives. To build the archive, make sure the RnAppAuth is added to the target dependencies in the Build Phases of the
prime_components project. Then go to Product and select Archive. This will rebuild and archive everything into one file.
Once done, the Organizer window should pop-up (which you can find in the Window menu):
From here you can validate your app. Click on Distribute to upload it to App Store Connect. Once that is done you should see the build in the submission page.
Screenshots
You need to add a few screenshots for your app. To do this simply go to the simulator menu - there is a screenshot option there. You might like to use a service like MockUPhone to give your screenshots a phone border.
Then you need to resize them in an app like Gimp. Your screenshots need to be the right size.
Once you’re finished, under the Prepare for Submission page select iPhone 5.5” Display (this is the only one you need to fill out), upload the screenshots you have.
Since October 2018 all apps in the App Store need a privacy policy, specified as a URL. Basically, you need to explain what data you collect and what you do with it. In this case, no data collected at all but you need to specify that and host a write-up for it on a website. There are several examples of what a privacy policy in this situation might look like such as this one.
Submission
Once all looks ready, click on the Submit for Review button in the preparation page. Here you will be asked to give your app a rating (you’ll be asked several questions about the app’s content). Make sure you’ve filled out the information of where reviewers will be able to contact you.
Once through, you should hear back within two days.
Learn More about React Native and Secure Authentication
You have successfully converted an Android React Native app to iOS and published to the App Store! We hope the review process went smoothly.
You can find the source code for this tutorial at oktadeveloper/okta-react-native-prime-components-example/tree/app-store.
You can also download the iOS app from the App Store.
If you’re interested to know more about React Native, iOS or secure user management with Okta, check out the following resources:
- Build a React Native Application and Authenticate with OAuth 2.0
- Build an iOS App with Secure Authentication in 20 Minutes
- Add Identity Management to Your iOS App
- How to Publish Your App on Apple’s App Store in 2018
Like what you learned today? Follow us on Twitter, like us on Facebook, check us out on LinkedIn, and subscribe to our YouTube channel.
Posted on by:
OktaDev
Hi! I write/post on behalf of Team OktaDev. I post blogs/tutorials that focus on React, Node, TypeScript, Java, Spring Boot, .NET, and much more.
Discussion | https://practicaldev-herokuapp-com.global.ssl.fastly.net/oktadev/build-an-ios-app-with-react-native-and-publish-it-to-the-app-store-340i | CC-MAIN-2020-34 | en | refinedweb |
flutter_grid_button
Flutter widget that arrange buttons in a grid. It is useful for making a number pad, calculator, and so on.
Getting Started
To use this plugin, add
flutter_grid_button as a dependency in your pubspec.yaml file.
dependencies: flutter_grid_button:
Import the library in your file.
import 'package:flutter_grid_button/flutter_grid_button.dart';
See the
example directory for a complete sample app using GridButton.
Or use the GridButton like below.
GridButton( onPressed: (String value) { /*...*/ }, items: [ [ GridButtonItem(title: "1"), GridButtonItem(title: "2"), GridButtonItem(title: "3", flex: 2), ], [ GridButtonItem(title: "a", value: "100", longPressValue: "long"), GridButtonItem(title: "b", color: Colors.lightBlue) ], ], )
Libraries
- Flutter widget that arrange buttons in a grid. | https://pub.dev/documentation/flutter_grid_button/latest/ | CC-MAIN-2020-34 | en | refinedweb |
Set Intrinsics
Intel® Streaming SIMD Extensions 2 (Intel® SSE2) intrinsics for floating-point set operations are listed in this topic. The prototypes for Intel® SSE2 intrinsics are in the
emmintrin.hheader file.
To use these intrinsics, include the
immintrin.hfile as follows:
#include <immintrin.h>
The load and set operations are similar in that both initialize
__m128ddata. However, the set operations take a double argument and are intended for initialization with constants, while the load operations take a double pointer argument and are intended to mimic the instructions for loading data from memory.
Some of the these intrinsics are composite intrinsics because they require more than one instruction to implement them.
The results of each intrinsic operation are placed in a register. The information about what is placed in each register appears in the tables below, in the detailed explanation for each intrinsic. For each intrinsic, the resulting register is represented by
R0and
R1, where
R0and
R1each represent one piece of the result register. | https://software.intel.com/content/www/us/en/develop/documentation/cpp-compiler-developer-guide-and-reference/top/compiler-reference/intrinsics/intrinsics-for-intel-streaming-simd-extensions-2-intel-sse2/floating-point-intrinsics-1/set-intrinsics.html | CC-MAIN-2020-34 | en | refinedweb |
Overriding inherited virtual functions
One way C++ supports code reuse is through inheritance. One base class implements common functionality. Then other classes inherit from it, essentially copying functionality from it. These other classes can add their own new functionality, or, more powerfully, they can override the base class functionality.
class Base { public: virtual const char* type() { return "Base"; } }; class Derived : public Base { public: virtual const char* type() { return "Derived"; } };
Overriding base class functionality is simple. Keeping such overrides working correctly is sometimes harder. The problem is that the override relationship is implicit: if the override doesn’t exactly match the signature of the desired function in the base class, it may not work correctly.
class Base { public: // Perhaps as part of an incomplete refactoring, // the base class's function changed its name. virtual const char* kind() { return "Base"; } }; class DerivedIncorrectly : public Base { public: virtual const char* type() { return "Derived"; } }; // BAD: code expecting kind() to work and sometimes // indicate Derived-ness no longer will.
Making the override relationship explicit
Some languages (Scala, C#, probably others) provide the ability to mark a derived class’s function as an override of an inherited function. C++98 included no such ability, but C++11 does, through the contextual
override keyword. When
override is used, that virtual member function must override one found on a base class. If it does not, it is a compile error.
class Base { public: virtual const char* kind() { return "Base"; } }; class DerivedIncorrectly : public Base { public: // This will cause a compile error: there's no type() // method on Base that this overrides. virtual const char* type() override { return "Derived"; } // This will work as intended. virtual const char* kind() override { return "Derived"; } };
Introducing
MOZ_OVERRIDE
The Mozilla Framework Based on Templates now includes support for the C++11 contextual
override keyword, encapsulated in the
MOZ_OVERRIDE macro in
. Simply place it at the end of the declaration of the relevant method, before any
mozilla/Types.h
= 0 or method body, like so:
#include "mozilla/Types.h"// MOZ_OVERRIDE has since moved... // ...to here class Base { public: virtual void f() = 0; }; class Derived1 : public Base { public: virtual void f() MOZ_OVERRIDE; }; class Derived2 : public Base { public: virtual void f() MOZ_OVERRIDE = 0; }; class Derived3 : public Base { public: virtual void f() MOZ_OVERRIDE { } };
MOZ_OVERRIDE will expand to use the C++11 construct in compilers which support it. Thus in such compilers misuse of
MOZ_OVERRIDE is an error. Even better, some of the compilers used by tinderbox support
override, so in many cases tinderbox will detect misuse. (Specifically, MSVC++ 2005 and later support it, so errors in cross-platform and Windows code won’t pass tinderbox . Much more recent versions of GCC and Clang support it as well, but these versions are too new for tinderbox to have picked them up yet — in the case of GCC too new to even have been released yet. 🙂 )
What about
NS_OVERRIDE?
It turns out there’s already a macro annotation to indicate an override relationship:
NS_OVERRIDE. This gunky XPCOM macro expands to a user attribute under gcc-like compilers. It’s only used by static analysis right now, so its value is limited. Unfortunately its position is different — necessarily so, because in the C++11
override position it would attach to the return value of the method:
class OldAndBustedDerived : public Base { public: NS_OVERRIDE virtual void f(); // annotates the method __attribute__(...) virtual void g(); // its expansion }; class Derived2 : public Base { public: // But in the MOZ_OVERRIDE position, it would annotate // f()'s return value. virtual void f() __attribute__(...); };
NS_OVERRIDE is now deprecated and should be replaced with
MOZ_OVERRIDE. With a little work, static analysis with new-enough compilers can likely look for
MOZ_OVERRIDE just as easily as for
NS_OVERRIDE. And since
MOZ_OVERRIDE works in non-static analysis builds, it’s arguably better in the majority of cases anyway. If you’re looking for an easy way to improve Mozilla code, changing
NS_OVERRIDE uses to use
MOZ_OVERRIDE would be a simple way to help.
Summary
If you’ve overridden an inherited virtual member function and you’re worried that that override might silently break at some point, annotate your override with
MOZ_OVERRIDE. This will cause some compilers to enforce an override relationship, making it much less likely that your intended relationship will break. | https://whereswalden.com/tag/override/ | CC-MAIN-2020-34 | en | refinedweb |
Try this notebook to reproduce the steps outlined below
Machine learning models can seem like magical savants. They can distinguish hot dogs from not-hot-dogs, but that’s long since an easy trick. My aunt’s parrot can do that too. But machine-learned models power voice-activated assistants that effortlessly understand noisy human speech, and cars that drive themselves more or less safely. It’s no wonder we assume these are at some level artificially ‘intelligent’.
What they don’t tell you is that these supervised models are more parrot than oracle. They learn by example, lots of them, and learn to emulate the connection between input and output that the examples suggest. Herein lies the problem that many companies face when embracing machine learning: the modeling is (relatively) easy. Having the right examples to learn from is not.
Obtaining these examples can be hard. One can’t start collecting the last five years of data, today, of course. Where there is data, it may be just ‘inputs’ without desired ‘outputs’ to learn. Worse, producing that label is typically a manual process. After all, if there were an automated process for it, there would be no need to relearn it as a model!
Where labels are not readily available, some manual labeling is inevitable. Fortunately, not all data has to be labeled. A class of techniques commonly called ‘active learning’ can make the process collaborative, wherein a model trained on some data helps identify data that are most useful to label next.
This example uses a Python library for active learning, modAL, to assist a human in labeling data for a simple text classification problem. It will show how Apache Spark can apply modAL at scale, and how open source tools like Hyperopt and mlflow, as integrated with Spark in Databricks, can help along the way.
Real-world Learning Problem: Classifying Consumer Complaints as “Distressed”
The US Consumer Financial Protection Bureau (CFPB) oversees financial institutions’ relationship with consumers. It handles complaints from consumers. They have published an anonymized data set of these complaints. Most is simple tabular data, but it also contains the free text of a consumer’s complaint (if present). Anyone who has handled customer support tickets will not be surprised by what they look like.
complaints_df = full_complaints_df.\ select(col("Complaint ID").alias("id"),\ col("Consumer complaint narrative").alias("complaint")).\ filter("complaint IS NOT NULL") display(complaints_df)
Imagine that the CFPB wants to prioritize or pre-emptively escalate handling of complaints that seem distressed: a consumer that is frightened or angry, would be raising voices on a call. It’s a straightforward text classification problem — if these complaints are already labeled accordingly. They are not. With over 440,000 complaints, it’s not realistic to hand-label them all.
Accepting that, your author labeled about 230 of the complaints (dataset).
labeled1_df = spark.read.option("header", True).option("inferSchema", True).\ csv(data_path + "/labeled.csv") input1_df = complaints_df.join(labeled1_df, "id") pool_df = complaints_df.join(labeled1_df, "id", how="left_anti") display(input1_df)
Using Spark ML to Build the Initial Classification Model
Spark ML can construct a basic TF-IDF embedding of the text at scale. At the moment, only the handful of labeled examples need transformation, but the entire data set will need this transformation later.
# Tokenize into words tokenizer = Tokenizer(inputCol="complaint", outputCol="tokenized") # Remove stopwords remover = StopWordsRemover(inputCol=tokenizer.getOutputCol(), outputCol="filtered") # Compute term frequencies and hash into buckets hashing_tf = HashingTF(inputCol=tokenizer.getOutputCol(), outputCol="hashed",\ numFeatures=1000) # Convert to TF-IDF idf = IDF(inputCol=hashing_tf.getOutputCol(), outputCol="features") pipeline = Pipeline(stages=[tokenizer, remover, hashing_tf, idf]) pipeline_model = pipeline.fit(complaints_df) # need array of float, not Spark vector, for pandas later tolist_udf = udf(lambda v: v.toArray().tolist(), ArrayType(FloatType())) featurized1_df = pipeline_model.transform(input1_df).\ select("id", "complaint", "features", "distressed").\ withColumn("features", tolist_udf("features"))
There is no value in applying distributed Spark ML at this scale. Instead, scikit-learn can fit the model on this tiny data set in seconds. However, Spark still has a role here. Fitting a model typically means fitting many variants on the model, varying ‘hyperparameters’ like more or less regularization. These variants can be fit in parallel by Spark. Hyperopt is an open-source tool integrated with Spark in Databricks that can drive this search for optimal hyperparameters in a way that learns what combinations work best, rather than just randomly searching.
The attached notebook has a full code listing, but an edit of the key portion of the implementation follows:
# Core function to train a model given train set and params def train_model(params, X_train, y_train): lr = LogisticRegression(solver='liblinear', max_iter=1000,\ penalty=params['penalty'], C=params['C'], random_state=seed) return lr.fit(X_train, y_train) # Wraps core modeling function to evaluate and return results for hyperopt def train_model_fmin(params): lr = train_model(params, X_train, y_train) loss = log_loss(y_val, lr.predict_proba(X_val)) # supplement auto logging in mlflow with accuracy accuracy = accuracy_score(y_val, lr.predict(X_val)) mlflow.log_metric('accuracy', accuracy) return {'status': STATUS_OK, 'loss': loss, 'accuracy': accuracy} penalties = ['l1', 'l2'] search_space = { 'C': hp.loguniform('C', -6, 1), 'penalty': hp.choice('penalty', penalties) } best_params = fmin(fn=train_model_fmin, space=search_space, algo=tpe.suggest, max_evals=32, trials=SparkTrials(parallelism=4), rstate=np.random.RandomState(seed)) # Need to translate this back from 0/1 in output to be used again as input best_params['penalty'] = penalties[best_params['penalty']] # Train final model on train + validation sets final_model = train_model(best_params,\ np.concatenate([X_train, X_val]),\ np.concatenate([y_train, y_val])) ... (X_train, X_val, X_test, y_train, y_val, y_test) = build_test_train_split(featurized1_pd, 80) (best_params, best_model) = find_best_lr_model(X_train, X_val, y_train, y_val) (accuracy, loss) = log_and_eval_model(best_model, best_params, X_test, y_test) ... Accuracy: 0.6 Loss: 0.6928265768789768
Hyperopt here tries 128 different hyperparameter combinations in its search. Here, it varies L1 vs L2 regularization penalty, and the strength of regularization, C. It returns the best settings it found, from which a final model is refit on train and validation data. Note that the results of these trials are automatically logged to mlflow, if using Databricks. The listing above shows that it’s possible to log additional metrics like accuracy, not just ‘loss’ that Hyperopt records. It’s clear, for example, that L1 regularization is better, incidentally:
For the run with best loss of about 0.7, accuracy is only 60%. Further tuning and more sophisticated models could improve this, but there is only so far this can get with a small training set. More labeled data is needed.
Applying modAL for Active Learning
This is where active learning comes in, via the modAL library. It is pleasantly simple to apply. When wrapped around a classifier or regressor that can return a probabilistic estimate of its prediction, it can analyze remaining data and decide which are most useful to label.
“Most useful” generally means labels for inputs that the classifier is currently most uncertain about. Knowing the label is more likely to improve the classifier than that of an input whose prediction is quite certain. modAL supports classifiers like logistic regression, whose output is a probability, via ActiveLearner.
learner = ActiveLearner(estimator=best_model, X_training=X_train, y_training=y_train)
It’s necessary to prepare the ‘pool’ of remaining data for querying. This means featurizing the rest of the data, so it’s handy that it was implemented with Spark ML:
featurized_pool_df = pipeline_model.transform(pool_df).\ select("id", "complaint", "features").\ withColumn("features", tolist_udf("features")).cache()
ActiveLearner’s query() method returns most-uncertain instances from an unlabeled data set, but it can’t directly operate in parallel via Spark. However Spark can apply it in parallel to chunks of the featurized data using a pandas UDF, which efficiently presents the data as pandas DataFrames or Series. Each can be independently queried with ActiveLearner then. Your author can only bear labeling a hundred or so more complaints, so this example tries to choose just about 0.02% of 440,000 in the pool:
query_fraction = 0.0002 @pandas_udf("boolean") def to_query(features_series): X_i = np.stack(features_series.to_numpy()) n = X_i.shape[0] query_idx, _ = learner.query(X_i, n_instances=math.ceil(n * query_fraction)) # Output has same size of inputs; most instances were not sampled for query query_result = pd.Series([False] * n) # Set True where ActiveLearner wants a label query_result.iloc[query_idx] = True return query_result with_query_df = featurized_pool_df.withColumn("query", to_query("features")) display(with_query_df.filter("query").select("complaint"))
Note that this isn’t quite the same as selecting the best 0.02% to query from the entire pool of 440,000, because this selects the top 0.02% from each chunk of that data as a pandas DataFrame separately. This won’t necessarily give the very best query candidates. The upside is parallelism. This tradeoff is probably useful to make in practical cases, as the results will still be relatively much more useful than most to query.
Understanding the Active Learner Queries
Indeed, the model returns probabilities between 49.9% and 50.1% for all complaints in the query. It is uncertain about all of them.
The input features can be plotted in two dimensions (via scikit-learn’s PCA) with seaborn to visualize not only which complaints are classified as ‘distressed’, but which the learner has chosen for labeling.
... queried = with_query_pd['query'] ax = sns.scatterplot(x=pca_pd[:,0], y=pca_pd[:,1],\ hue=best_model.predict(with_query_np), style=~queried, size=~queried,\ alpha=0.8, legend=False) # Zoom in on the interesting part ax.set_xlim(-0.75,1) ax.set_ylim(-1,1) display()
Here, orange points are ‘distressed’ and blue are not, according to the model so far. The larger points are some of those selected to query; they are all, as it happens, negative.
Model Classification of (Projected) Sample, with Queried Points
Although hard to interpret visually, it does seem to choose points in regions where both classifications appear, not from uniform regions.
Effects on Machine Learning Accuracy
Your author downloaded the query set from Databricks as CSV and dutifully labeled almost 100 more in a favorite spreadsheet program, then exported and uploaded it back to storage as CSV. A low-tech process like this — a column in a spreadsheet — may be just fine for small scale labeling. Of course it is also possible to save the query as a table that an external system uses to manage labeling.
The same process above can be repeated with the new, larger data set. The result? Cutting to the chase, it’s 68% accuracy. Your mileage may vary. This time Hyperopt’s search (see listing above) over hyperparameters found better models from nearly the first few trials and improved from there, rather than plateauing at about 60% accuracy.
Learning Strategy Variations on modAL Queries
modAL has other strategies for choosing query candidates: max uncertainty sampling, max margin sampling and entropy sampling. These differ in the multi-class case, but are equivalent in a binary classification case such as this.
Also, for example, ActiveLearner’s query_strategy can be customized to use “uncertainty batch sampling” to return queries ranked by uncertainty. This may be useful to prepare a longer list of queries to be labeled in order of usefulness as much as time permits before the next model build and query loop.
def preset_batch(classifier, X_pool): return uncertainty_batch_sampling(classifier, X_pool, 100) learner = ActiveLearner(estimator=..., query_strategy=preset_batch)
Active Learning with Streaming
Above, the entire pool of candidates were available for the query() method. This is useful when choosing the best ones to query in a batch context. However it might be necessary to apply the same ideas to a stream of data, one at a time.
It’s already of course possible to score the model against a stream of complaints and flag the ones that are predicted to be ‘distressed’ with high probability for preemptive escalation. However it might equally be useful, in some cases, to flag highly-uncertain inputs for evaluation by a data science team, before the model and learner are rebuilt.
@pandas_udf("boolean") def uncertain(features_series): X_i = np.stack(features_series.to_numpy()) n = X_i.shape[0] uncertain = pd.Series([False] * n) # Set True where uncertainty is high. Uncertainty is at most 0.5 uncertain[classifier_uncertainty(learner, X_i) > 0.4999] = True return uncertain display(pool2_df.filter(uncertain(pool2_df['features'])).drop("features"))
In the simple binary classification case, this essentially reduces to finding where the model outputs a probability near 0.5. However modAL offers other possibilities for quantifying uncertainty that do differ in the multi-class case.
Getting Started with Your Active Learning Problem
When we learn from data with supervised machine learning techniques, it’s not how much data we have that counts, but how much labeled data. In some cases labels are expensive to acquire, manually. Fortunately active learning techniques, as implemented in open source tools like modAL, can help humans prioritize what to label. The recipe is:
- Label a small amount of data, if not already available
- Train an initial model
- Apply active learning to decide what to label
- Train a new model and repeat until accuracy is sufficient or you run out of labelers’ patience
modAL can be applied at scale with Apache Spark, and integrates well with other standard open source tools like scikit-learn, Hyperopt, and mlflow.
Complaints about this blog? Please contact the CFPB. | https://databricks.com/blog/2020/01/16/better-machine-learning-through-active-learning.html | CC-MAIN-2020-34 | en | refinedweb |
DEBSOURCES
Skip Quicknav
sources / aolserver4 / 4.0.10
2005-01-18 tag aolserver_v40_r10
2005-01-18 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.19): Added missing prototype for
Ns_CompressGzip.
BUMP: 4.0.10
2005-01-12 Dossy Shiobara <dossy@panoptic.com>
* nsd/nsd.h (1.77.2.8), nsd/adpcmds.c (1.14.2.1), nsd/adprequest.c
(1.16.2.2), nsd/compress.c (1.1.2.3), nsd/server.c (1.27.2.1),
nsd/tclcmds.c (1.38.2.1), tests/new/http-test-config.tcl
(1.1.2.2), tests/new/ns_adp_compress.test (1.1.2.1),
tests/new/servers/server1/pages/ns_adp_compress.adp (1.1.2.1):
Support on-the-fly gzip compression of ADP page responses based
on HTTP request's Accept-Encoding header and ns_adp_compress
control mechanism.
2004-12-01 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.17): Provide NS_VERSION_NUM definition to
make conditionalized testing of AOLserver version at build time
easy.
2004-11-22 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.16): BUMP: 4.0.10a
2004-11-22 tag aolserver_v40_r9
2004-11-22 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.15): BUMP: 4.0.9
2004-11-20 Dossy Shiobara <dossy@panoptic.com>
* nsd/tclsched.c (1.5.2.1): Option parsing needed to be more
careful, leading to segfaults when a bad command like
[ns_schedule_proc -thread -only] is executed. Closes SF Bug
#1068836. Backport from HEAD.
2004-11-19 Dossy Shiobara <dossy@panoptic.com>
* configure (1.15.2.8), configure.in (1.13.2.6): autoconf now
detects if libgcc is built shared, in which case LIBS needs
-lgcc_s. Without it, the nsd binary will fail to link because of
unresolved symbols __umoddi3 and __udivdi3 in nsd/dsprintf.c.
2004-11-19 Dossy Shiobara <dossy@panoptic.com>
* nsd/Makefile (1.39.2.2): Adding -lz to LIBS is now redundant.
2004-11-19 Dossy Shiobara <dossy@panoptic.com>
* include/nsthread.h (1.24.2.4): Need to include <inttypes.h> on
some platforms (OS X, Solaris 10) to get C99 "uint32_t" and other
types. Backport from HEAD.
2004-11-19 Dossy Shiobara <dossy@panoptic.com>
* configure (1.15.2.7), configure.in (1.13.2.5),
include/Makefile.global.in (1.16.2.1), nsd/compress.c (1.1.2.2):
Add --with-zlib configure option (on by default) and add ifdef's
to nsd/compress.c. Backport from HEAD.
2004-11-17 Dossy Shiobara <dossy@panoptic.com>
* nsd/adprequest.c (1.16.2.1): Don't send Content-Length if
streaming is on. Backport from HEAD.
2004-11-15 Dossy Shiobara <dossy@panoptic.com>
* nsd/nsmain.c (1.52.2.3): AOLserver will now allow setting the fd
limit (via "ulimit -Hn", etc.) and only log a warning if it
exceeds FD_SETSIZE. Do this at your own risk, as things which
still use select(), i.e., Tcl, are likely to break. Backported
from HEAD.
2004-11-05 Dossy Shiobara <dossy@panoptic.com>
* nsd/sockcallback.c (1.12.2.3): Dereferencing cbPtr->nextPtr is
dangerous since cbPtr could have been freed.
2004-09-30 tag aolserver_v40_r9_b2
2004-09-30 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.13): BUMP: 4.0.9b
2004-09-30 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.12), nsd/tclhttp.c (1.16.2.5),
nsd/sockcallback.c (1.12.2.2): Implement
Ns_SockCancelCallbackEx() in order to correctly cancel actions in
the SockCallbackThread. Fix for SF Bug #1037196. Backported
from HEAD for 4.0.9.
2004-09-29 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.11), nsd/tclhttp.c (1.16.2.4),
nsd/sockcallback.c (1.12.2.1): Fix a thread hang issue when
ns_http fails but HttpCancel() never executes because poll()
returns revent == POLLPRI. Closes SF Bug #1037196. Backported
from HEAD for 4.0.9.
2004-09-24 Dossy Shiobara <dossy@panoptic.com>
* include/nsthread.h (1.24.2.2): Win32 supports the
get{addr,name}info() API, so use it. Backported from HEAD for
4.0.9.
2004-09-24 Dossy Shiobara <dossy@panoptic.com>
* nsd/dns.c (1.7.2.3): Small memory leak introduced on platforms w/
getaddrinfo. Closes SF Bug #1033575. Backport from HEAD for
4.0.9.
2004-09-22 Dossy Shiobara <dossy@panoptic.com>
* configure (1.15.2.6), configure.in (1.13.2.4): get{addr,name}info
on Solaris 9 is in -lsocket. Backported from HEAD.
2004-09-21 Dossy Shiobara <dossy@panoptic.com>
* configure (1.15.2.5), configure.in (1.13.2.3): Ensure we use the
compiler from the Tcl build during AOLserver configure process,
unless it's explicitly overrided during the AOLserver build.
Backported from HEAD for 4.0.9.
2004-09-21 Dossy Shiobara <dossy@panoptic.com>
* aclocal.m4 (1.1.4.3): Make detection of gethostby{addr,name}_r
more robust. Closes SF Bug #1032231. Backported from HEAD for
4.0.9.
2004-09-20 Dossy Shiobara <dossy@panoptic.com>
* nsd/: nsmain.c (1.52.2.2), nsd.h (1.77.2.7), unix.c (1.15.2.5):
Need to set the dumpable flag on Linux in order to get a core
file after uid/gid is changed. Closes SF Bug #1031599.
Backported from HEAD for 4.0.9a.
2004-09-17 Dossy Shiobara <dossy@panoptic.com>
* nsd/connio.c (1.12.2.2): Ns_ConnSend() now bubbles up the error
from NsSockSend() on first send, which is what the C API
documentation says. Closes SF Bug #1029512. Backported from
HEAD for 4.0.9a.
2004-09-17 Dossy Shiobara <dossy@panoptic.com>
* nsd/driver.c (1.17.2.9): "stopped" already initalized to 1, which
means NsWaitDriversShutdown() will never timeout even when it
should, which means trigPipe always gets closed immediately which
causes DriverThread to Ns_Fatal() on line 848. Closes SF Bug
#1029918.
2004-09-08 Dossy Shiobara <dossy@panoptic.com>
* nslog/nslog.html (1.1.10.1): Updated nslog module documentation.
Closes SF Bug #466236. Backported from HEAD.
2004-09-08 Dossy Shiobara <dossy@panoptic.com>
* nscgi/nscgi.html (1.1.10.2): Add datatype for config options to
doc. Backported from HEAD.
2004-09-07 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.10): BUMP: 4.0.9a
2004-09-07 tag aolserver_v40_r8
2004-09-07 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.9): BUMP: 4.0.8
2004-09-07 Dossy Shiobara <dossy@panoptic.com>
* README (1.4.2.1): Updated for 4.0.8.
2004-09-03 Dossy Shiobara <dossy@panoptic.com>
* nscgi/nscgi.html (1.1.10.1): Updated nscgi module documentation
for 4.0. Closes SF Bug #465907. Backported from HEAD.
2004-08-25 Dossy Shiobara <dossy@panoptic.com>
* nsd/queue.c (1.23.2.1): If reqPtr is NULL, close the connection
too.
2004-08-25 Dossy Shiobara <dossy@panoptic.com>
* nsd/driver.c (1.17.2.8): Previous code to eat leading blanks
assumed CR/LF, but some clients only send LF. Code has been
cleaned up and corrected to handle this properly.
2004-08-20 Dossy Shiobara <dossy@panoptic.com>
* Makefile (1.44.2.2), tests/new/all.tcl (1.1.2.1),
tests/new/harness.tcl (1.2.2.1), tests/new/ns_hrefs.test
(1.1.2.1), tests/new/test-ns_addrbyhost.adp (1.1.2.1),
tests/new/test-ns_hostbyaddr.adp (1.1.2.1),
tests/new/test-ns_hrefs.adp (1.1.2.1): Implement automated tests
that can be run from a stand-alone tclsh. New Makefile target
added called "test" which runs the tests.
2004-08-18 Dossy Shiobara <dossy@panoptic.com>
* tcl/fastpath.tcl (1.8.2.2): If _ns_dirlist gets an URL without a
trailing slash, issue a 302 redirect back to the same url WITH
the trailing slash. Fixes SF Bug #935907. Backported from HEAD.
2004-08-17 Dossy Shiobara <dossy@panoptic.com>
* nsd/fastpath.c (1.18.2.2): Minor change to eliminate Win32
compile-time warning. Closes SF Bug #696806. Backported from
HEAD.
2004-08-14 Dossy Shiobara <dossy@panoptic.com>
* aclocal.m4 (1.1.4.2), configure (1.15.2.3), nsd/dns.c (1.7.2.2):
Solaris 7 uses gethostbyaddr_r(), and the autoconf and GetHost()
versions didn't work. Fixed now. Backported from HEAD.
2004-08-14 Dossy Shiobara <dossy@panoptic.com>
* nsd/dns.c (1.7.2.1), aclocal.m4 (1.1.4.1), configure.in
(1.13.2.2), configure (1.15.2.2): gethostbyaddr() and
gethostbyname() are not thread-safe. Use the new getaddrinfo()
and getnameinfo() API where available, otherwise use
gethostbyaddr_r() and gethostbyname_r() if available. Otherwise,
continue to use the non-safe versions but emit a warning at
configure time. Fixes SF Bug #1008721. Backported from HEAD.
2004-08-13 Dossy Shiobara <dossy@panoptic.com>
* win32/: nscgi/nscgi.dsp (1.5.2.1), nscp/nscp.dsp (1.5.2.1),
nsd/nsd.dsp (1.14.2.1), nsdb/nsdb.dsp (1.1.2.1), nslog/nslog.dsp
(1.5.2.1), nsperm/nsperm.dsp (1.5.2.1), nssock/nssock.dsp
(1.8.2.1), nsthread/nsthread.dsp (1.7.2.1),
threadtest/threadtest.dsp (1.5.2.1): Change Win32 .dsp files to
reflect change in Tcl from "tcl84td.lib" to "tcl84tg.lib". Fixes
SF Bug #996342. Backported from HEAD.
2004-08-13 Dossy Shiobara <dossy@panoptic.com>
* nsd/tclmisc.c (1.30.2.1): ns_hrefs is now more robust. Fixes SF
Bug #995078. Backported from HEAD.
2004-08-11 Dossy Shiobara <dossy@panoptic.com>
* nsd/nsconf.c (1.32.2.3): Inability to resolve nsconf.hostname to
set nsconf.address is no longer fatal, and instead defaults to
"0.0.0.0". Fixes SF Bug #994072. Backported from HEAD.
2004-08-11 Dossy Shiobara <dossy@panoptic.com>
* nsd/driver.c (1.17.2.7): Fixed crash bug when virtual servers are
configured, but the "hostname" parameter didn't match any of the
virtual servers. Fixed by introducing new "defaultserver"
parameter in the comm. config that must refer to one of the
virtual servers being defined. Backported from HEAD.
2004-08-11 Dossy Shiobara <dossy@panoptic.com>
* sample-config.tcl (1.11.2.2): Add "defaultserver" parameter in
sample config. Backported from HEAD.
2004-08-05 Rob Crittenden <rcrittenden0569@aol.com>
* nsd/tclhttp.c: Add new option to ns_http wait, -servicetime, so
you can capture how long the HTTP request took.
2004-07-28 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.8): BUMP: 4.0.8a
2004-07-28 Dossy Shiobara <dossy@panoptic.com>
* configure (1.15.2.1), configure.in (1.13.2.1): Clean up
configure.in, regenerate configure with autoconf2.13, and clear
CCRPATH/LDRPATH if CCRFLAGS/LDRFLAGS are empty. Closes SF Bug
#640754. Backported from HEAD.
2004-07-19 tag aolserver_v40_r7
2004-07-19 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.7, aolserver_v40_r7): BUMP: 4.0.7
2004-07-18 Dossy Shiobara <dossy@panoptic.com>
* nsd/return.c (1.33.2.6): Fix bug where internal redirect for 401
omitted including the HTTP auth. "WWW-Authenticate:" header.
Fixes bug #674033. Backported from HEAD.
2004-07-18 Dossy Shiobara <dossy@panoptic.com>
* nsd/: nsd.h (1.77.2.6), init.c (1.5.2.1), nsconf.c (1.32.2.2):
Ns_GetAddrByHost() reports errors via Ns_Log(), so calls to it
should be done after Ns_Log has been initialized, otherwise very
unhelpful error messages are produced. In particular, this
happens when the server is started and the hostname as returned
by gethostname() cannot be resolved, because the network
interface is down AND no entry exists in /etc/hosts. Closes SF
Bug #868362. Backported from HEAD.
2004-07-16 Dossy Shiobara <dossy@panoptic.com>
* nsd/driver.c (1.17.2.6): Setting request->method to static
storage, which later gets ns_free()'d in Ns_FreeRequest(), caused
server to crash.
2004-07-16 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.6): BUMP: 4.0.7a
2004-07-16 tag aolserver_v40_r6
2004-07-16 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h (1.55.2.5): BUMP: 4.0.6
2004-07-15 Tim Suh <suhti@aol.com>
* nsd/return.c: keepalive is enabled for response codes other than 200
2004-07-13 Dossy Shiobara <dossy@panoptic.com>
* nsd/: driver.c (1.17.2.5), op.c (1.11.2.1): Change to make HTTP
request "Host:" header mandatory for HTTP/1.1 connections by
returning 400 Bad Request response. Closes SF Bug #787728.
Also, changed virtual server code to use the "hostname" param
from the "ns/module/nssock" section to map the default virtual
server based on the value (hostname) from the
"ns/module/nssock/servers" section, when the "Host:" header is
either not specified (HTTP/1.0) or is not found in the virtual
server table. Closes SF Bug #812036. Backport from HEAD, but
not straight patch due to difference in conn/request handling in
4.0 vs. 4.1.
2004-07-13 Dossy Shiobara <dossy@panoptic.com>
* nslog/nslog.c (1.14.2.1): conn->headers can be NULL causing
segfault. Closes SF Bug #990439. Backported from HEAD.
2004-07-13 Dossy Shiobara <dossy@panoptic.com>
* include/nsthread.h (1.24.2.1): OpenBSD 3.5 doesn't define
ENOTSUP, so we'll define it ourselves. Closes SF Bug #985076.
Backported from HEAD.
2004-07-02 Dossy Shiobara <dossy@panoptic.com>
* nsd/mimetypes.c (1.11.2.1): Ns_GetMimeType() was returning
defaultType instead of noextType if the path contained a
directory with a "." but the filename component had no extension.
Fixes bug #739049. Backported from HEAD.
2004-07-02 Dossy Shiobara <dossy@panoptic.com>
* nsd/: fastpath.c (1.18.2.1), return.c (1.33.2.4): Enable ADP/Tcl
code to override Last-Modified: header from ns_respond when
-headers AND -file are specified. Closes bug #879076. Backport
from HEAD, for 4.0.6.
2004-07-02 Dossy Shiobara <dossy@panoptic.com>
* nsd/tclresp.c (1.16.2.1): lots of refactoring of ns_respond code
to remove duplication. Backport from HEAD.
2004-07-02 Dossy Shiobara <dossy@panoptic.com>
* nsd/init.tcl (1.30.2.1): ns_eval of script containing comments
(i.e., lines starting with "#") cause an error because $args is a
list, which gets evaluated differently than a plain string
script. Fixes bug #833940. Backported from HEAD.
2004-07-01 Dossy Shiobara <dossy@panoptic.com>
* nsd/: nsd.h (1.77.2.5), nsmain.c (1.52.2.1): Ensure that
supplementary groups from /etc/group are set if -u username is
specified, or dropped if a uid is specified so that the nsd
doesn't run with root's supplementary groups. Closes bug
#425401. Backport from HEAD.
2004-07-01 Dossy Shiobara <dossy@panoptic.com>
* nsd/nsd.h (1.77.2.4): trivial - eliminate compiler warning for
nsd/nsmain.c
2004-07-01 Dossy Shiobara <dossy@panoptic.com>
* nsthread/tls.c (1.2.2.1): Make the Tcl_Panic() message from
Ns_TlsGet() and Ns_TlsSet() include the full function name to aid
in debugging. (Backport from HEAD.)
2004-06-30 17:20 Dossy Shiobara <dossy@panoptic.com>
* nsd/unix.c: Ensure synchronous signals are handled correctly
under LinuxThreads. Possible fix for Bug #982955.
Backported from HEAD for 4.0.6.
2004-06-30 01:24 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h: Fix build on alpha arch, removing extra INT64
typedef. Closes bug #896962. (Backport from HEAD.)
2004-06-23 Rob Crittenden <rcrittenden0569@aol.com>
* nsd/log.c: ns_log now logs to a custom logger as well.
2004-06-14 20:41 Dossy Shiobara <dossy@panoptic.com>
* nsd/return.c: unnecessary test for data != NULL actually caused
part of bug #971016 when fastpath.cache=false and
fastpath.mmap=true and the file requested is zero bytes, mmap()
returns 0 which gets passed along as data == NULL, causing
ReturnCharData() to not flush the queued headers. removing the
if is safe as Ns_WriteConn will simply flush any queued data
2004-06-14 20:40 Dossy Shiobara <dossy@panoptic.com>
* nsd/connio.c: If nsend == 0, we would never call Ns_WriteConn to
flush the queued headers. This could happen when we're sending
zero bytes of data as a response. This fixes bug #971016 in the
case where fastpath.cache=false and fastpath.mmap=false and a
zero byte file is requested.
2004-06-14 16:40 Dossy Shiobara <dossy@panoptic.com>
* nsd/return.c: one-liner fix for sending Content-Length header
for content of zero bytes (Bug #971016)
2004-06-03 Rob Crittenden <rcrittenden0569@aol.com>
* TAG aolserver_v40_r5
2004-06-03 Rob Crittenden <rcrittenden0569@aol.com>
* Makefile: remove Makefile.module during distclean
* include/ns.h, nsd/log.c: Allow users to override logging functions.
* nsd/str.c: Fix crash bug in Ns_Trim* when trimming NULL strings.
* nsd/: nsconf.c, driver.c, return.c, nsd.h: Add new bool config
option, keepaliveallmethods, which enables HTTP/1.0 Keep-Alives for
all valid methods. By default this is false.
2004-03-26 Mark Page <mpagenva@aol.com>
* nsd/nsd.h:
* nsd/driver.c:
* sample-config.tcl: Add configurable logging of errors which cause the
driver to drop a incoming connection socket. Logging goes to the
server log. Following new bool config params are added to the socket
driver's section (e.g., nssock, etc): readtimeoutlogging,
serverrejectlogging, sockerrorlogging,
sockshuterrorlogging.
2004-02-27 14:14 Dossy Shiobara <dossy@panoptic.com>
* include/ns.h: fix for bug #906011 "include/ns.h version not
bumped"
2004-02-26 14:37 Dossy Shiobara <dossy@panoptic.com>
* nsd/unix.c: uid_t is supposed to be unsigned, but apparently
isn't on OSX, apparently.
2004-02-19 13:22 Dossy Shiobara <dossy@panoptic.com>
* nsdb/: dbinit.c, dbtcl.c: fix "ns_db gethandle -timeout" so that
when timeout < 0 it blocks forever, timeout == 0 is poll, and
timeout > 0 times out after timeout seconds
2004-02-18 11:35 Dossy Shiobara <dossy@panoptic.com>
* nsperm/nsperm.c: fixed bug #899364, restoring old nsperm
functionality as it was in 3.x.
2003-11-23 mpagenva <mpagenva@aol.com>
* nsd/tclhttp.c: remove validity check on method param to ns_http
queue, since methods in addition to put and post can be valid.
* tcl/fastpath.tcl: make configuable: a) logging to serverlog
fastpath update requests (some configs may be fine with the
logging to the access log which can be easily obtained).
b) automatic backfill of implied directory tree on put.
2003-11-19 pkhincha <pkhincha@aol.com>
* maxinput to throttle the # of bytes
* on request.
* Removed ThreadJoin of driver thread.
2003-11-03 pkhincha <pkhincha@aol.com>
* nsd/urlspace.c: removed initing of mutex
* nsd/nsmain.c: calling NsWaitDriversShutdown
2003-11-01 Zoran Vasiljevic <zv@archiware.com>
* tcl/file.tcl: fixed broken argument convention for the
unused argument of ns_sourceproc.
2003-10-28 Zoran Vasiljevic <zv@archiware.com>
* nsd/tclatclose.c: fixed typo in command usage text
2003-10-09 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_20
* doc/ns_job.n:
* tests/api/ns_job.adp:
* nsd/tcljob.c: Change timeout specification to be ns_time
based.
2003-10-21 Elizabeth Thomas <eathomas93@aol.com>
* nsd/init.tcl: Removing lazyproc code from 4.0 to enable it
to be declared GM. Solution is being refined and may be added
in later release or add-on module.
2003-10-14 Paul Moosman <pwmoosman@aol.com>
* nsd/tcljob.c: Fix to ns_job, where it was attempting to access
a deleted queue.
2003-10-09 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_18
2003-10-09 Elizabeth Thomas <eathomas93@aol.com>
* nsd/init.tcl: Fix syntax error in check for null proc.
2003-10-08 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_17
* nsd/init.tcl (ns_eval): Minor change to track change to ns_job.
2003-10-08 Paul Moosman <pwmoosman@aol.com>
* nsd/tcljob.c: Minor change to ns_job joblist return to be
consistent with similar aolserver api's.
2003-10-07 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_16
* nsd/init.tcl (ns_eval): The early 4.0 ns_eval had been
waiting for the completion of integrating script changes into the
server's init script. This change adds the ability to return
without waiting for the init script integration completion (as the
default). A new switch modifies this behavior to force it to wait
for the completion of init script integration. Added another
switch to request a report of ns_eval backlog.
* nsd/adpeval.c (LogError): Limit the amount of script text added
into the errorInfo string, to keep from flowing adp script texts
of unlimited length into the server log.
2003-10-06 Paul Moosman <pwmoosman@aol.com>
* nsd/tcljob.c: Replaced ctime_r with ns_ctime to fix a win32
compile problem. This change should fix bug #811802.
Fixed a potential deadlock case.
Fixed a problem where the maxthreads option was getting ignored.
2003-10-01 Elizabeth Thomas <eathomas93@aol.com>
* nsd/init.tcl: Fix to _ns_lzproc_load to handle subtle behavior with
respect to namespaces and the test to see if the proc will be successfully
recognized. Also, fix to protect against infinite loop on unknown processing
if null command is executed.
2003-09-22 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_15
2003-09-22 Paul Moosman <pwmoosman@aol.com>
* nsd/tcljob.c: Add options to ns_job Api, for waitany, delete(queue),
listjobs, etc.
2003-09-19 Mark Page <mpagenva@aol.com>
* nsd/adprequest.c:
nsd/adpeval.c: Fix error where
xxx.adp --> ns_adp_parse --> ns_adp_include --> ns_adp_puts results in
the puts text going directly into the final result buffer, rather then
to the intermediate buffer to be returned by ns_adp_parse to the xxx.adp
page code.
2003-09-12 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_14
2003-09-11 Elizabeth Thomas <eathomas93@aol.com>
* nsd/init.tcl: Add 'lazyproc' functionality. Controlled by
ns/parameters config parm 'lazyprocdef' (defaults to 'false')
When 'true', we do not put proc definitions in the interp
init script, but instead wrap the tcl 'unknown' command and
evaluate them on the first reference. Also wraps the tcl 'info'
command to intercept queries about procs not yet in the interpreter.
2003-09-03 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_13
* nsd/tclinit.c (NsTclICtlObjCmd): Fix intermittant core dumps
occurring during oncleanup processing. The error is in the Tcl_Obj
for the script passed into ns_ictl on* callbacks was being saved
and passed to the callbacks (this Tcl_Obj was then being shared
amoung Interps, which is not allowed).
Now, extract a copy of the script string, and pass that to the callbacks.
2003-08-27 Elizabeth Thomas <eathomas93@aol.com>
* nsd/adprequest.c: Complete 8/12 fix of not
logging error for ns_adp_break
2003-08-26 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_12
2003-08-26 Elizabeth Thomas <eathomas93@aol.com>
* nsd/tclinit.c: Fix the 'oncleanup' option of ns_ictl.
Modify behavior of Ns_RegisterAtDelete so callbacks are
run before the interp is destroyed. Expose with new 'ondelete'
option to ns_ictl.
2003-08-25 Mark Page <mpagenva@aol.com>
* nsd/adprequest.c (): Suppress production of the result data for
requests with SKIPBODY set.
* nsd/return.c (ReturnCharData): Allow headers to be returned for
requests with SKIPBODY; e.g., HEAD requests.
2003-08-21 Zoran Vasiljevic <zoran@archiware.com>
* nsd/tclfile.c: properly detach and attach the Tcl channel
out and in the current interpreter.
2003-08-19 Rahul Bhargava <rahul032213@aol.com>
* nsd/return.c: Updated to support HTTP/1.1 Transfer Chunk Encoding
Headers only.
2003-08-19 Nathan Folkman <shmooved@aol.com>
* nsd/return.c: Updated to include status code from:
RFC 2616 (Hypertext Transfer Protocol -- HTTP/1.1) and
RFC 2518 (HTTP Extensions for Distributed Authoring -- WEBDAV).
2003-08-12 Elizabeth Thomas <eathomas93@aol.com>
* nsd/adprequest.c: Don't log ns_adp_abort or ns_adp_break as errors.
2003-08-08 Elizabeth Thomas <eathomas93@aol.com>
* nsd/mimetypes.c:
* sample_config.tcl: Add support for xhtml mime type. (RFE #563417)
* TAG aolserver_v4_r0_beta_11
2003-08-06 Elizabeth Thomas <eathomas93@aol.com>
* nsd/tclset.c: Fix ns_set split argument checking. (#757849)
2003-08-05 Elizabeth Thomas <eathomas93@aol.com>
* nsd/conn.c:
* nslog/nslog.c:
* include/ns.h:
* sample-config.tcl: Merge in feature from 3.5 branch (with simpler
implementation) for logging of request execution time in access log.
To turn on feature add:
ns_section "ns/server/${servername}/module/nslog"
ns_param logreqtime true
By default the option is disabled. If enabled the connection's
request time will be appended to the access log before the
extended headers (if configured).
2003-07-18 Elizabeth Thomas <eathomas93@aol.com>
* nsd/tclinit.c: Add optional mutex to serialize interp initialization.
With large init scripts and many threads, there is severe malloc
lock contention while tcl evaluates the init script (and populates
its memory pool). Serializing the initialization reduces the thrashing and
results in faster startup.
* nsd/nsconf.c, nsconf.h, nsd.h: Add config variable 'tclinitlock'
which activates the above. Defaults to false if not specified.
* TAG aolserver_v4_r0_beta_10
>>>>>>> 1.190
2003-07-18 Mark Page <mpagenva@aol.com>
* nsd/adpeval.c (AdpEval): Check adp.outputPtr validity before
use. It can get reset within this adp evaluation loop from
commands like ns_respond (when it does an internal redirect for
the file not found case). In this case, it's appropriate that
further text from this page code is not appended to the result, as
other code had determined that the result was complete.
2003-07-12 Zoran Vasiljevic <zoran@archiware.com>
* nslog/nslog.c: the "X-Forwarded-For" header existence is examined
when logging the remote user. This allows for logging the real
remote user wnen it commes from some proxy and/or load balancer.
Thanks for Gustaf Neumann of XOTcl for the patch. This implements
the RFE #770054.
2003-07-10 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_9
2003-07-01 Mark Page <mpagenva@aol.com>
* nsd/init.tcl (ns_eval): Protect against nested ns_eval calls,
which would otherwise lead to deadlocks.
2003-06-26 Mark Page <mpagenva@aol.com>
* nsd/adpeval.c: Fix problem where ns_adp_include was not propogating
errors.
2003-06-25 Mark Page <mpagenva@aol.com>
* nsd/init.tcl: (ns_eval) Fix thread-safety issue with ns_eval,
where multiple simultanous usages can clobber a change.
(_ns_getscript) suppress saving the Tcl global variable 'env' into
the init script. Tcl's init takes care of 'env', and including it
into the init script would cause SetEnvs at interp create that are
unneeded and undesired.
2003-06-18 Mark Page <mpagenva@aol.com>
* nsthread/thread.c (Ns_ThreadCreate): Fix typo in Ns_ThreadCreate
that was causing it to ignore the stacksize parameter.
* nsd/init.tcl (_ns_eval): Fix ns_eval to prevent it's bleeding of
unintended Tcl environment change to the global interp state.
2003-06-06 Zoran Vasiljevic <zoran@archiware.com>
* nsd/queue.c: fixed "connsperthread" config parameter
as reported in bug item #749801. Default is set to
"0" i.e. thread will perform unlimited number of
connections (never exit) unless it's idle timer
(if configured) expires.
2003-05-31 Zoran Vasiljevic <zoran@archiware.com>
* nsd/config.c: uses Ns_TclDestroyInterp instead of the
Tcl_DeleteInterp.
* nsthread/nsthreadtest.c:
* nsd/info.c:
* nsd/nsmain.c:
* include/Makefile.module.in:
* configure:
* configure.in: added --disable-shared so we can now build the
nsd image statically.
2003-05-31 Zoran Vasiljevic <zoran@archiware.com>
* nsd/cache.c:
* include/ns.h:
* doc/Ns_Cache.3: added C-API for Ns_CacheTryLock as in RFE #725704
2003-05-30 Mark Page <mpagenva@aol.com>
* nsd/tclthread.c: fix problem in ns_thread begindetached api.
This code was failing to create the new thread as detached.
Also corrected for the Ns_TclDetachedThread C api. As a
result of this change, non-detached threads will return their
TclEval result to Ns_ThreadExit, making it available to a
thread join.
2003-05-28 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_8
2003-05-28 Mark Page <mpagenva@aol.com>
* nsd/tclimg.c: Use binary channel to read img (Thanks to Dossy).
Eliminate double error string; Corrrect compiler warning on Seek.
* tcl/form.c: Fix to ns_querygetall to suppress null sublists. Also,
make the defaulting semantics work as described.
2003-05-24 Zoran Vasiljevic <zoran@archiware.com>
* nsd/info.c: added workaround for Tcl_GetMemoryInfo() which
is not defined in Tcl if somebody undefines USE_THREAD_ALLOC.
Generally, this call should be avoided altogether.
* nsd/tclinit.c: added call to Tcl_FinalizeThread() in the
DeleteInterps() to properly finalize Tcl data on thread exit,
thus closing the re-appearing memory leak from V3.3 nsd.
2003-05-20 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_7
2003-05-20 Mark Page <mpagenva@aol.com>
* nsd/tclimg.c: Addition error checks in gif size read.
* nsd/adpcmds.c: Error check calls to ns_adp funcs.
* nsd/tclinit.c: Error check calls to Ns_TclGetConn and Ns_TclServerInterp.
2003-05-19 Mark Page <mpagenva@aol.com>
* nsd/tclinit.c: suppress byte-compile for interp init scripts
* nsd/tclthread.c: fix fmr.
2003-05-16 Zoran Vasiljevic <zoran@archiware.com>
* nsdb/dbinit.c: fixed hash table initialization in IncrCount
to TCL_ONE_WORD_KEYS instead of TCL_STRING_KEYS. Credits to
Jean-Fabrice RABAUTE for the bug report.
2003-05-14 Zoran Vasiljevic <zoran@archiware.com>
* nsd/tclthread.c: fixed NsTclCondObjCmd to be compatible
to the 3.x pendant in way it threats the optional timeout
argument. The 3.x reverted to indefinite (i.e. non-timewait)
condvar waits when the optional "timeout" argument was given
as zero.
The 4.x version just exited with NS_TIMEOUT (= 0) in such
cases breaking Tcl scripts written for 3.x.
The corrective measure is to check the passed timeout value
and if == 0, revert to non-timewait condition waits as the
3.x does (did).
2003-05-13 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_6
2003-05-12 Mark Page <mpagenva@aol.com>
* nsd/urlencode.c : (bug fix) urlencode was passing through too
many characters unencoded. In particular, the '+' was getting
passed through, which causes unsymmetric encode/decode since
'+' in encoded string translates to ' '(space).
2003-04-25 Mark Page <mpagenva@aol.com>
* nsd/tclvar.c (NsTclNsvArrayObjCmd): (bug fix) nsv_array exists
must return true if an nsv exists, regardless of the number of
array elements in the nsv.
2003-04-24 Mark Page <mpagenva@aol.com>
* nsd/queue.c (ConnRun): Ensure that a Internal Error status is
returned to the client if an error status is returned from a
pre-auth filter. Previously, the connection was simply closed,
causing difficult to diagnose problems to the client. Also
allow traces to run in this situation, so that access logging can
occur.
2003-04-23 Mark Page <mpagenva@aol.com>
* nsd/log.c (NsTclLogObjCmd): (bug fix) Tweeked previous fix to
suppress trailing space on output.
2003-04-22 Nathan Folkman <shmooved@aol.com>
* nsd/log.c: (bug fix) Fixed bug causing first two string
args of "ns_log" to be improperly concatendated.
2003-04-16 Mark Page <mpagenva@aol.com>
* nsd/modload.c (NsLoadModules): (bug) Failed parsing the explicit
initialization specification properly.
2003-04-10 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_5
2003-04-07 Mark Page <mpagenva@aol.com>
* nsd/tclthread.c (NsTclThread): ensure that the server has
completed it's initializtion prior to initiating TclEval.
* nsd/nsmain.c (Ns_WaitForStartup): add dirty-read of the
conf.started flag.
2003-04-04 Mark Page <mpagenva@aol.com>
* nsd/tclinit.c:
* nsd/tclcmds.c: Moved interp tracing functionality into ns_ictl
api as one of it's subfunctions, removing the
ns_register_interptrace api previously created.
2003-04-03 Mark Page <mpagenva@aol.com>
* nsd/tclinit.c:
* nsd/tclcmds.c: Provide tcl api that exposes Ns_TclInitInterps
and Ns_TclRegisterTrace. ns_register_interptrace.
2003-03-30 Scott S. Goodwin <scott@scottg.net>
* include/ns.h:
nsd/driver.c:
nssock/nssock.c:
nsssl/nsssl.c: Modified Ns_DriverInit. Instead of passing all args
as parameters to Ns_DriverInit, a comm module must now create an
Ns_DriverInitData structure and populate it with appropriate values
(see include/ns.h) and pass that in the call to Ns_DriverInit. The
Ns_DriverInitData structure is versioned so that we can extend it
later without affecting other modules.
2003-03-28 Mark Page <mpagenva@aol.com>
* nsd/tclhttp.c: (bug) Fix uninitialized hdrs var, was causing segfault.
2003-03-21 Mark Page <mpagenva@aol.com>
* TAG aolserver_v4_r0_beta_4
2003-03-19 Mark Page <mpagenva@aol.com>
* nsd/tclhttp.c: Added method argument to ns_http queue api to
allow sending POSTs as well as GETs.
2003-03-19 Mark Page <mpagenva@aol.com>
* nsext/nsext.c: Change back to using ns_socketpair for local
proxies, to retain PEEK functionality.
2003-03-19 Zoran Vasiljevic <zoran@archiware.com>
* nsd/modload.c: added fallback for loading regular
shared libraries in addition to bundles on Darwin.
* include/tcl.h: added set of version macros
* nsd/config.c: added Ns_GetVersion API call.
2003-03-10 Scott S. Goodwin <scott@scottg.net>
* nscgi/nscgi.c: (bug) SERVER_NAME is now set correctly.
2003-03-10 Mark Page <mpagenva@aol.com>
* nsd/sched.c: (bug) Fix problem with shutting down event threads
(these service detachted thread processing) on a server shutdown.
2003-03-07 Nathan Folkman <shmooved@aol.com>
* TAG aolserver_v4_r0_beta_3
2003-03-07 Zoran Vasiljevic <zoran@archiware.com>
* include/ns.h:
* nscgi/nscgi.c:
* nscp/nscp.c:
* nsd/adpeval.c:
* nsd/adpparse.c:
* nsd/binder.c:
* nsd/config.c:
* nsd/conn.c:
* nsd/connio.c:
* nsd/dns.c:
* nsd/driver.c:
* nsd/dstring.c:
* nsd/encoding.c:
* nsd/fastpath.c:
* nsd/index.c:
* nsd/info.c:
* nsd/lisp.c:
* nsd/listen.c:
* nsd/log.c:
* nsd/modload.c:
* nsd/nsmain.c:
* nsd/pidfile.c:
* nsd/queue.c:
* nsd/request.c:
* nsd/rollfile.c:
* nsd/sched.c:
* nsd/sockcallback.c:
* nsd/tclatclose.c:
* nsd/tclfile.c:
* nsd/tclhttp.c:
* nsd/tclimg.c:
* nsd/tclinit.c:
* nsd/tcljob.c:
* nsd/tclmisc.c:
* nsd/tclshare.c:
* nsd/tclsock.c:
* nsd/tclvar.c:
* nsd/tclxkeylist.c:
* nsd/urlencode.c:
* nsd/urlspace.c:
* nsdb/dbinit.c:
* nsdb/dbtcl.c:
* nsext/nsext.c:
* nslog/nslog.c:
* nspd/log.c:
* nspd/main.c:
* nsperm/nsperm.c:
* nsthread/mutex.c:
* nsthread/nsthreadtest.c:
* nsthread/pthread.c:
o. removed unused variables
o. fixed warnings about non-initialized vars
o. CONST-ified according to Tcl 8.4+ rules
* bin/init.tcl: _ns_getscript forces import of
namespaced commands
* tcl/init.tcl: sets auto_path to start with
our private library first
* include/Makefile.global.in: allows for building
with Solaris 2.6 and later
2003-03-06 Mark Page <mpagenva@aol.com>
* nsd/adpeval.c: Change defn of objs field of InterpPage to size
1, since some compilers don't like 0 sized arrays.
* nsd/urlencode.c:
* nsd/queue.c:
* nsd/server.c:
* nsd/urlencode.c:
* nsd/encoding.c:
* nsd/nsd.h:
* nsd/form.c:
* nsd/conn.c:
* include/ns.h:
* tcl/form.tcl:
* tcl/charsets.tcl(new): Added Tcl I18N support functions from
OACS, with some changes to work within 4.0.
2003-03-05 Zoran Vasiljevic <zoran@archiware.com>
* nsd/init.tcl: added handling of commands imported from
other namespaces in _ns_getscript procedure.
2003-03-05 Mark Page <mpagenva@aol.com>
* nsd/adpeval.c: (fix) Fixed handling of Tcl errors from script.
2003-03-05 Mark Page <mpagenva@aol.com>
* nsd/adpeval.c:
* nsd/adpcmds.c:
* nsd/nsd.h: (patch) Added optional switches to ns_adp_parse;
-cwd <path>, -savedresult <varname>
-savedresult supports usages which require the adp script's result
separate from the output buffer (which is the func result)
-cwd supports prespecifying the initial cwd for which the script
will be executed.
2003-03-03 Nathan Folkman <shmooved@aol.com>
* nscgi/nscgi.c: (bug fix) Applied patch to set SCRIPT_NAME
which is passed as an environment variable to the CGI script.
SF bug 230479.
2003-02-25 Nathan Folkman <shmooved@aol.com>
* nsd/init.tcl: (patch) Added logging of errorInfo
and errorCode globals to _ns_sourcefile command.
SF patch 690025.
* sample-config.tcl:
* tcl/fastpath.c: (bug fix) Added fast path configuration
example. Fixed bug that was adding an extra slash to
directory listings in _ns_dirlist. SF bug 682077.
* nsd/tclimg.c: (bug fix) Fixed ns_jpegsize command for
images which contained a DHT. Removed AppendDims command
which has been replaced with AppendObjDims. SF bug 685055.
2003-02-07 Elizabeth Thomas <eathomas93@aol.com>
* TAG aolserver_v4_r0_beta_2
* tcl/sendmail.tcl: (bug fix) SF bugs 669217/669844
Fix handling of addressees so we don't lose friendly address name
* configure: fix additional defaults from cc to gcc
2003-02-06 Mark Page <mpagenva@aol.com>
* nsd/return.c: (bug fix) SF bug 674033.
(bug fix) Correct the status code for BadRequest returns.
2003-02-06 Jamie Rasmussen <jrasmuss@mle.ie>
* nsthread/winthread.c: (bug fix) SF bug 675033.
(bug fix) Fixed crash on second DLL_THREAD_DETACH.
2003-02-05 Elizabeth Thomas <eathomas93@aol.com>
* nsext.c: Fix LocalProxy function to call Ns_CloseOnExec
after the file descriptors have been opened instead of before
2003-02-04 Jamie Rasmussen <jrasmuss@mle.ie>
* include/nsthread.h:
* include/ns.h:
* nscgi/nscgi.c:
* nscp/nscp.c:
* nsd/adpeval.c:
* nsd/driver.c:
* nsd/encoding.c:
* nsd/exec.c:
* nsd/fastpath.c:
* nsd/fd.c:
* nsd/info.c:
* nsd/init.c:
* nsd/listen.c:
* nsd/modload.c:
* nsd/nsd.h:
* nsd/nsmain.c:
* nsd/pathname.c:
* nsd/request.c:
* nsd/server.c:
* nsd/sock.c:
* nsd/sockcallback.c:
* nsd/tclenv.c:
* nsd/tclfile.c:
* nsd/tclhttp.c:
* nsd/tclimg.c:
* nsd/tclsock.c:
* nsd/tclxkeylist.c:
* nsd/urlencode.c:
* nsd/urlopen.c:
* nsd/getopt.c:
* nsd/getopt.h:
* nsd/nswin32.c:
* nssock/nssock.c:
* win32: Added Win32 support and build files
2003-02-04 Nathan Folkman <shmooved@aol.com>
* nsd/tclmisc.c: (bug fix) Fixed arg checking bug in
NsTclStrftimeObjCmd (ns_fmttime) API.
2003-02-03 Jamie Rasmussen <jrasmuss@mle.ie>
* tcl/sendmail.tcl: (bug fix) SF bug 632265.
* Fixed minor spelling errors in comments.
2003-02-01 Nathan Folkman <shmooved@aol.com>
* tcl/stats.tcl: Consolidated web based stats interface into
a single Tcl file.
* sample-config.tcl: Added web stats configuration.
2003-01-31 Mark Page <mpagenva@aol.com>
* nsd/conn.c:
* nsd/connio.c:
* nsd/encoding.c:
* nsd/form.c:
* nsd/nsconf.c:
* nsd/nsd.h:
* nsd/queue.c:
* nsd/return.c:
* nsd/tclcmds.c:
* nsd/tclresp.c:
* nsd/urlencode.c:
* include/ns.h: added in I18N capabilities derived from the OACS
I18N design. This set of changes is just those which are
supported within the nsd C-code.
* sample-config.tcl: Add text for I18N specific config.
2003-01-28 Nathan Folkman <shmooved@aol.com>
* nsd/server.c:
* tcl/fastpath.tcl: (bug fix) Tcl code was updated to reflect a
a change made earlier to server.c, in which all fast path related
configuration was moved from ns/server/<server> to
ns/server/<server>/fastpath. This change will require you to
update your configuration file to reflect the new configuration
path for any fast path options.
*** INCOMPATIBILITY ***
2003-01-28 Nathan Folkman <shmooved@aol.com>
* nsd/init.tcl: (bug fix) Updated ns_eval command to mark Tcl interp for
deletion in the case of a TCL_ERROR only. Updated ns_eval to properly
handle an arbitrarly long number of args. SF bug 675506.
2003-01-24 Elizabeth Thomas <eathomas93@aol.com>
* include/Makefile.global.in:
* README: Added $(PURIFY) variable back from 3.4 to facilitate
easy purify compile.
* configure: Made gcc the default value for $CC instead of cc.
2003-01-23 Elizabeth Thomas <eathomas93@aol.com>
* Tagged first 4.0 beta: aolserver_v4_r0_beta_1
2003-01-19 Nathan Folkman <shmooved@aol.com>
* nscp/nscp.c: Cleaned up log messages to be more consistent
with other server messages. Moved user name from thread name into
log notice. Control port logging now disabled by default. Added
more detailed configuration instructions to sample-config.tcl.
2003-01-18 Jim Davidson <jgdavidson@aol.com>
* nsd/auth.c:
* nsd/conn.c:
* nsd/form.c:
* nsd/httptime.c:
* nsd/info.c:
* nsd/log.c:
* nsd/mimetypes.c:
* nsd/nsconf.c:
* nsd/nsd.h:
* nsd/nsmain.c:
* nsd/pathname.c:
* nsd/random.c:
* nsd/tclcmds.c:
* nsd/tclfile.c:
* nsd/tclhttp.c:
* nsd/tclimg.c:
* nsd/tclinit.c:
* nsd/tclmisc.c:
* nsd/tclrequest.c:
* nsd/tclresp.c:
* nsd/tclset.c:
* nsd/tclsock.c:
* nsd/tclthread.c:
* nsd/urlencode.c:
* nsd/urlopen.c: Removed old string commands.
* nsd/conn.c:
* nsd/connio.c:
* nsd/driver.c:
* nsd/init.c:
* nsd/nsd.h:
* nsd/queue.c:
* nsd/return.c:
* nsd/server.c:
* nsd/tclinit.c: Moved Host header mapping code from
queue.c to driver.c to catch cases of unmapped Host's.
Also, updated the Conn and Sock structures to maintain the
servPtr and location correctly Host header based connections.
* nsthread/Makefile:
* nsthread/cond.c (removed):
* nsthread/error.c:
* nsthread/memory.c:
* nsthread/mutex.c:
* nsthread/nsthreadtest.c:
* nsthread/pthread.c (added):
* nsthread/reentrant.c:
* nsthread/thread.c:
* nsthread/thread.h:
* nsthread/time.c:
* nsthread/tls.c:
* nsthread/winthread.c (added):
* include/nsthread.h: Brought forward nsthread library
from 3.5 which includes support for Win32.
2003-01-18 Zoran Vasiljevic <zoran@archiware.com>
* nsd/init.tcl: Summary of changes:
o. added _ns_getpackages to enable "package require".
o. fixed various issues in ns_getscript proc related to
of standard Tcl commands.
o. fixed ns_eval to return value/error and made compatible
with standard Tcl "eval" and AOLserver "ns_eval" from 3.x
o. made the entire file little bit more readable.
2003-01-17 Mark Page <mpagenva@aol.com>
* nsd/driver.c: Change to SockRead; if request has a
content-length, null-terminate the content at the specified
length. This fixes a problem when some browsers add extra CRLF
characters beyond the specified content-length on a POST (see this
by using IE to POST data).
2003-01-16 Elizabeth Thomas <eathomas93@aol.com>
* nsd/tclmisc.c: Fix WordEndsInSemi so that ns_striphtml correctly
* handles ampersands that are not followed by a space or semicolon
2002-11-06 Jeremy Collins <jcollins@phpsource.net>
* nsd/adpparse.c: Changed ParseAtts to make it compatible with
how parsing works in 3.x.
* nsd/init.tcl: Fixed namespace bug.
2002-11-05 Jeremy Collins <jcollins@phpsource.net>
* nsd/adpparse.c: Fixed a bug in Parse. It was not parsing
registered tags inside of html tags (ex. <td bgcolor='<tag n='v'>'> )
* nsd/tclset.c: Fixed a bug with ns_set tcl commands.
ns_set idelkey|delkey would not actually delete the key.
2002-11-02 Jim Davidson <jgdavidson@aol.com>
* nsd/fastpath.c: Fixed bug with non-server specific cache names.
2002-11-01 Jeremy Collins <jcollins@phpsource.net>
* nsd/adpparse.c: Fixed a small bug in ParseAtts. It failed
to properly parse attribute values with spaces in them.
2002-10-29 Jim Davidson <jgdavidson@aol.com>
* sample-config.tcl: Updated with examples for connection
thread pools and Host header virtual servers.
* Makefile: Uses /bin/sh to invoke install-doc.
* doc/install-doc: Uses /bin/sh to invoke mkLinks.
* nsd/form.c:
* nsd/conn.c:
* tcl/form.tcl: Changed "ns_conn files" command to just
return names of file upload widgets, moving access to other
meta data to new fileoffset, filelength, and fileheaders
subcommands. Also, removed the ns_conn string command
instead of updating.
* nsd/nsd.h:
* nsd/driver.c:
* nsd/nsmain.c:
* nsd/server.c:
* nsd/queue.c: Implemented multiple named thread pools
for virtual servers and Host header based virtual server
selection. See sample-config.tcl for config example.
* nsd/info.c: Fixed crash bug with NULL server.
* nsd/tclcmds.c: Removed NsTclConnCmd and NsTclServerCmd
string commands.
2002-10-14 Jim Davidson <jgdavidson@aol.com>
* doc/install-doc (new): New script to install and cross
link the man pages.
* Makefile:
* include/Makefile.module: Added .PHONY targets and man
page install target.
* nsd/conn.c: Made "ns_conn copy" use Tcl_Write instead
of Tcl_WriteChars to fix binary file upload bug.
* nsd/form.c: Fixed bug where Ns_ConnGetQuery (i.e.,
ns_conn form) could not handle binary data in multpart file
uploads. Also, "ns_conn files" now returns file type.
* nsd/log.c: Thread ids are now formatted as unsigned
long.
* include/ns.h:
* nsd/config.c:
* nsd/tclinit.c:
* nsd/tclcmd.c:
* nsd/tclsock.c:
* nsd/main.c: Added support for libnsd.so to be loaded
into a standard (thread enabled) tclsh or linked into a
custom tclsh. Calling Ns_TclInit from a custom tclsh or
non-server AOLserver commands (e.g., adds ns_set but not
ns_adp_puts).
* nsd/server.c:
* nsd/tcljob.c: Changed ns_job command to create and queue
jobs to named queues instead of per-server queues.
* nsd/tclthread.c: Added a special Tcl address object type
to speed access to the object id's.
* nsd/sched.c: Threaded events now use a thread pool
instead of create/delete each time.
* tcl/form.tcl: Fixed bug accessing uploaded binary files
with the ns_getform proc and added ns_getformfile proc to
address the ".tmpfile" security issue.
2002-09-28 Jim Davidson <jgdavidson@aol.com>
* nsd/adpparse.c:
* nsd/auth.c:
* nsd/conn.c:
* nsd/connio.c:
* nsd/driver.c:
* nsd/dstring.c:
* nsd/filter.c:
* nsd/init.c:
* nsd/log.c:
* nsd/main.c:
* nsd/modload.c:
* nsd/nsd.h:
* nsd/nsmain.c:
* nsd/queue.c:
* nsd/return.c:
* nsd/server.c:
* nsd/tclenv.c:
* nsd/tclinit.c:
* nsd/tclthread.c:
* include/ns.h: Added missing AOLserver 3.x API's including
static module support, Ns_TclRegisterAt traces, connection
I/O functions, loadable comm driver stubs, and more.
* configure:
* configure.in:
* nsd/exec.c: Removed weird USE_PROCTHREAD code.
* nsd/init.tcl: Uses "ns_ictl modules" for module list.
* nscgi/nscgi.c: Uses Ns_CopyEnviron, renamed from
Ns_GetEnvironment.
* Makefile: Fixed install bug for install-sh.
* README: Updated to match AOLserver 3.5. Various outdated
docs removed.
2002-09-10 Jim Davidson <jgdavidson@aol.com>
* Makefile:
* INSTALL (new):
* aclocal.m4 (new):
* configure (new):
* configure.in (new):
* include/Makefile.global (removed):
* include/Mkaefile.global.in (new):
* include/Makefile.module: New autoconf-based configuration
and build.
* nsd/log.c:
* nsd/tclenv.c: Updated to used new autoconf-based compile
info.
2002-08-24 Jim Davidson <jgdavidson@aol.com>
* nsd/filter.c:
* nsd/server.c:
* nsd/tclatclose.c:
* nsd/tclvar.c:
* nsd/tclinit.c:
* nsd/tcljob.c:
* nsd/nsd.h: Moved private struct definitions out of nsd.h
back to files which depend on them, e.g., struct Filter.
* nsd/tclatclose.c:
* nsd/tclinit.c: Moved Ns_TclRegisterDeferred to tclinit.c.
* nsd/adpeval.c:
* nsd/tclsock.c:
* nsd/tclinitc: Eliminated NsTclEval in favor of Tcl_EvalEx.
* nsd/log.c:
* nsd/nsconf.h:
* nsd/nsconf.c: Removed complicated and dubious log
buffering option. The new ns_logctl feature can be used
to batch noisy requests.
* nsd/tclinit.c:
* nsd/tclcmds.c:
* nsd/init.tcl: Added new ns_init command to replace the
nsv-based namespace copy/update mechanism. The init.tcl
is now called only at startup.
* conn.c:
* driver.c:
* queue.c:
* nsd.h: Connection times and timeouts now maintained with
Ns_Time-based microsecond resolution.
2002-07-14 Jim Davidson <jgdavidson@aol.com>
* nsd/log.c:
* nsd/tclcmds.c: Added the ns_logctl command with options
to hold, release, flush, etc. the log messages in a thread.
* nsd/adpcmds.c:
* nsd/urlopen.c: Switched to more object-correct
Tcl_ObjSetVar2.
2002-07-08 Jim Davidson <jgdavidson@aol.com>
* nsd/tclthread.c: Cleaned up the object-based commands
by collecting common argument and new object allocation
code into single GetArgs function.
2002-07-07 Jim Davidson <jgdavidson@aol.com>
* nsd/tclvar.c: Removed string commands because it was
messy maintaining both.
* nsd/info.c:
* nsd/queue.c:
* nsd/tclcmds.c:
* nsd/tclset.c: Added object commands.
* nsd/tclobj.c:
* nsd/tclmisc.c: Updated Ns_Time type code to handle simple
single-integer times without microsecond resolution.
* include/ns.h:
* include/Makefile.global:
* Makefile: Updated for AOLserver beta4 release to coincide
with Tcl beta1 release.
Otherwise, minor edits to new object commands in several
places.
2002-07-05 Jim Davidson <jgdavidson@aol.com>
* nsd/nsd.h:
* nsd/adpcmds.c:
* nsd/adpeval.c:
* nsd/adprequest.c:
* nsd/tclcmds.c: Updated remaining ADP commands to be
object-based. Because the NsInterp->adp struct now uses
Tcl_Obj's for call frame args, the string commands were
just dumped.
2002-06-25 Scott S. Goodwin <scott@scottg.net>
* nsd/tclvar.c:
* nsd/tclcmds.c: Reimplemented nsv commands as object commands.-06-12 Jeremy Collins <jeremy.collins@phpsource.net>
* nsd/conn.c:
* nsd/tclcmds.c: Reimplemented "ns_conn" as an obj based
command. In the process I also modified NsTclConnObjCmd to use
Tcl_GetIndexFromObj. This should improve performance as well as
the readability of the code.
* nsd/auth.c:
* nsd/form.c:
* nsd/httptime.c:
* nsd/log.c:
* nsd/mimetypes.c:
* nsd/nsmain.c:
* nsd/pathname.c:
* nsd/random.c:
* nsd/tclatclose.c:
* nsd/tclfile.c:
* nsd/tclhttp.c:
* nsd/tclimg.c:
* nsd/tclinit.c:
* nsd/tclmisc.c:
* nsd/tclrequest.c:
* nsd/tclresp.c:
* nsd/tclsock.c:
* nsd/tclthread.c:
* nsd/urlencode.c:
* nsd/urlopen.c: Cleaned up the way we were setting the result
on tcl errors.
2002-06-12 Jim Davidson <jgdavidson@aol.com>
* include/nsthread.h:
* nsthread/mutex.c:
* nsthread/thread.c:
* nsd/info.c: Rename Ns_MutexEnum and Ns_ThreadEnum to
Ns_MutexList and Ns_ThreadList to not conflict with pre-4.0
definitions of removed functions.
* nsthread/Makefile
* nsthread/nshtreadtest.c (new file): Added simple program
to test thread interface.
* nsthread/thread.h:
* nsthread/cslock.c:
* nsthread/rwlock.c: Added new NsMutexInitNext function
to consistantly name mutexes in internal objects.
* nsthread/sema.c: Restored AOLserver 3.x implementation
using Ns_Mutex and Ns_Cond objects. The API's in <semaphore.h>
were not implemented on OS/X.
2002-06-10 Jim Davidson <jgdavidson@aol.com>
* include/Makefile.global:
* include/Makefile.module: Added support for dynamic
library init procs set via the LIBINIT make variable.
* Makefile:
* nsthread/compat.c:
* nsthread/cond.c:
* nsthread/cslock.c
* nsthread/error.c:
* nsthread/fork.c:
* nsthread/master.c:
* nsthread/memory.c:
* nsthread/mutex.c:
* nsthread/osxcompat.c:
* nsthread/osxcompat.h:
* nsthread/reentrant.c:
* nsthread/rwlock.c:
* nsthread/sema.c:
* nsthread/signal.c:
* nsthread/thread.c:
* nsthread/thread.h (new file):
* nsthread/time.c:
* nsthread/tls.c: Moved from nsd as separate nsthread
library.
* include/ns.h:
* include/nsthread.h: Include of tcl.h moved to nsthread.h
from ns.h.
* nsd/Makefile
* nsd/init.c (new file):
* nsd/binder.c:
* nsd/cache.c:
* nsd/config.c:
* nsd/encoding.c:
* nsd/exec.c:
* nsd/info.c:
* nsd/listen.c:
* nsd/log.c:
* nsd/mimetypes.c:
* nsd/modload.c:
* nsd/nsd.h:
* nsd/nsmain.c:
* nsd/nsconf.c:
* nsd/proc.c:
* nsd/sched.c:
* nsd/server.c:
* nsd/tclinit.c:
* nsd/urlspace.c: Various runtime initializations collected
into dynamic library load time init via NsdInit in init.c.
2002-06-08 Jim Davidson <jgdavidson@aol.com>
* include/Makefile.global
* include/Makefile.module: Support for building programs
along with dynamic libraries and modules. Also, fixed bug
setting -install_name on OS/X.
* nsd/Makefile: Use of updated Makefile.module and include
osxcompat.o on OS/X.
* nsd/nsd.h:
* nsd/osxcompat.h:
* nsd/osxcompat.c: Compat functions moved from ../nsosx.
* nsosx/README (removed):
* nsosx/Makefile (removed):
* nsosx/nsosx.c (removed): Tcl no longer requires any
compat functions, remainder moved into nsd.
Otherwise, minor tweaks throughout to silence compiler
warnings.
2002-06-05 Jim Davidson <jgdavidson@aol.com>
* Makefile:
* include/Makefile.global: Added tclmemdbg flag to compile
Tcl and AOLserver with TCL_MEM_DEBUG option.
* nsd/unix.o:
* nsosx/README (new file):
* nsosx/Makefile (new file):
* nsosx/nsosx.o (new file): Hacks for Apple OS/X removed
from nsd/unix.o and moved to nsosx.o as a Tcl compat object.
See README for instructions.
* nsd/nsd.h:
* nsd/server.c:
* nsd/adpparse.c:
* nsd/adpcmds.c:
* nsd/adpeval.c: Added support for new ns_adp_safeeval
and ns_adp_registerproc commands. Also, registered tags
can now be modified after startup.
* include/Makefile.module: Updated to allow building of
dynamic library of public routines to go with dynamic
module, e.g., libnsdb.so with nsdb.so.
* nsext/Makefile:
* nspd/Makefile:
* nspd/msg.c (removed):
* nsext/msg.c (moved from nspd): Moved Ns_Ext API from
libnspd.a static library to libnsext.so dynamic library as
it's used by both nsext.so and proxy drivers.
* nsdb/Makefile:
* nsdb/nsext.c (new file): Moved public API for nsdb out
of nsdb.so module and into libnsdb.so dynamic library.
2002-05-15 Jim Davidson <jgdavidson@aol.com>
* Makefile:
* include/Makefile.global:
* tcl8.3.4 (removed): As of Tcl version 8.4., no modifications
to the Tcl sources are required for AOLserver. Therefore,
the hacked 8.3.4 sources have been removed. Going forward
you'll need to checkout the Tcl source from Sourceforge
into the directory specified in include/Makefile.global
(currently ../tcl8.4). The top level Makefile includes
the "tcl-checkout" and "tcl-update" targets which should
* include/ns.h:
* nsd/server.c:
* nsd/nsd.h:
* nsd/tclcmds.c:
* nsd/tclinit.c:
* nsd/init.tcl:
* nsd/dbdrv.c (removed):
* nsd/dbinit.c (removed):
* nsd/dbtcl.c (removed):
* nsd/dbutil.c (removed):
* nsdb/dbinit.c (new):
* nsdb/dbdrv.c (new):
* nsdb/dbtcl.c (new):
* nsdb/dbutil.c (new):
* include/nsdb.h (new): Moved the NsDb interface from core
to new nsdb module. Simply loading nsdb.so should work as
before. Goal is to enable full replacement of NsDb in the
future.
* nsd/cache.c:
* nsd/callbacks.c:
* nsd/listen.c:
* nsd/nsconf.c:
* nsd/op.c:
* nsd/sched.c:
* nsd/server.c:
* nsd/sockcallback.c:
* nsd/urlspace.c:
* nsext/nsext.c:
* nslog/nslog.c:
* nslog/nslog.c: Simple mutex name updates.
* nscgi/nscgi.c: Minor bug fixes
* nsd/adpeval.c: Fixed read of freed data.
* nsd/tclinit.c: Fixed crash bug of null interp delete.
* nsd/exec.c:
* include/Makefile.global: Support for process manager
thread enabled with -DUSE_PROCTHREAD to route all process
create/wait through a single thread for Linux threads.
2002-02-24 Jim Davidson <jgdavidson@aol.com>
* nsd/nsd.h
* nsd/unix.c:
* tcl8.3.4/unix/tclLoadDyld.c: Hacks for routines missing
from OS/X. The implementation of sigwait() is not strictly
correct but appears good enough for AOLserver's use.
* Makefile:
* nsd/Makefile:
* nsmain/Makefile:
* include/Makefile.global:
* include/Makefile.module:
* include/Makefile.library (removed): Updates for linking
modules against the nsd shared library and for library
filenames which don't end in .so.
* nsext/Makefile
* nspd/Makefile: Moved proxy message code from nsext to
nspd, now a static library.
* nsd/main.c:
* nsd/init.c:
* nsd/Makefile:
* nsmain/*:
* sample-config.tcl:
* tcl2ini.tcl:
* ini2tcl.tcl:
* Makefile: Moved build and install of nsd and init.tcl
into nsd directory and install of sample config to top
level Makefile. Added tcl2ini.tcl and ini2tcl.tcl config
file utilities.
2002-02-07 Jeff Hobbs <jeffh@ActiveState.com>
* nsmain/init.tcl:
* nsmain/sample-config.tcl:
* nsssl/keygen.tcl:
* tcl/debug.tcl:
* tcl/fastpath.tcl:
* tcl/file.tcl:
* tcl/form.tcl:
* tcl/http.tcl:
* tcl/nsdb.tcl:
* tcl/sendmail.tcl:
* tcl/util.tcl: code cleanup to brace exprs and fix indentation
2001-12-05 Jim Davidson <jgdavidson@aol.com>
* nsd/tclthread: Tcl threads now return their string result
via ns_thread wait.
2001-12-20 Scott S. Goodwin <scott@scottg.net>
* include/Makefile.library: Changed RFLAG to RPATH, and took out
$(AOLSERVER)/lib:
$(LDSO) -o $(LIB) $(OBJS) $(LIBS) $(RFLAG) $(AOLSERVER)/lib
now reads:
$(LDSO) -o $(LIB) $(OBJS) $(LIBS) $(RPATH)
which is what I think was intended. Still have the problem
that $(AOLSERVER)/lib must already exist.
2001-11-05 Jim Davidson <jgdavidson@aol.com>
* Removed support for Win32, removing both the build/test
environment and updating the code to be standard Unix style.
Among other style changes such as changing SOCKET's to
simple Unix style int's, the short lived Ns_Buf structure
was also eliminated in favor of the Unix standard struct
iovec.
* Removed support for older non-pthread Unix platforms such
as HP/10 and SGI native.
* Updated Tcl to version to Tcl 8.3.4, replacing tclAlloc.c
with a modified version of what was libnsthread's fast pool
allocator including support for fast direct Tcl_Obj
allocation. Also added a few functions to tclUnixThrd.c
for thread safety (e.g., readdir_r and localtime_r support)
and fixed up tcl.m4 for better FreeBSD 4.4 and Solaris
thread builds.
* ns_malloc, Ns_ThreadMalloc, and Ns_PoolAlloc all now
simply call Tcl_Alloc which is always enabled. The previous
-z (enable) and -p (disable) command line flags are ignored.
* Integrated remainder of libnsthread, now standard pthreads
and compatible with Tcl pthread code, into libnsd.so.
* Updated libnsd.so to use poll() instead of select() where
possible.
* Removed the code which would attempt to determine when
the sock callbacks and scheduler were idle before completing
startup. The code was overly complex and not strictly
correct.
* Removed the -k and -K shutdown/restart options which was
not entirely safe.
* Removed the child-process privleged port Ns_SockListen
code in nsd/binder.c. Binding privleged ports (e.g., port
80) now requires the -b or -B command line methods introduced
in 3.4, e.g., "nsd -ft nsd.tcl -b myhost:80". The binder
code, while clever, was a potential security risk.
* Cleaned up some lingering sloppy uses of Ns_ConfigGet
and other older macros. Old macro and function definitions
can be disabled by defining NS_NOCOMPAT as is done when
compiling the core server and modules.
* Incremented version to 4.0b2.
2001-08-29 Scott S. Goodwin <scott@scottg.net>
* https.tcl: made fixes to ns_httppost per Rick Lansky at
bom.com. He also suggested I allow the Content-type to be
passed in as a parameter, so I've added that too.
2001-08-27 Scott S. Goodwin <scott@scottg.net>
* https.tcl: added ns_httppost, that is called with url,
rqset, qsset and timeout. The qsset is an ns_set with
key/values that will be turned into user=scottg&pass=1234,
for example, and passed as content in the POST.
2001-08-17 Scott S. Goodwin <scott@scottg.net>
* tcl/http.tcl: moved rqset to be the last arg passed to
ns_httpget so it wouldn't break existing code. I should
have done it that way in the first place.
2001-08-15 Scott S. Goodwin <scott@scottg.net>
* tcl/http.tcl: add the rqset param as the second argument to
ns_httpget, which in turn calls ns_httpsopen and passes the rqset
to it. The change is for consistency so that you can use cookies
with ns_httpget as well.
2001-07-16 Scott S. Goodwin <scott@scottg.net>
* tcl/http.tcl: you can now do ns_httpopen GET /index.html;
the script will automatically prepend
to the url.
2001-06-30 Dossy Shiobara <scott@scottg.net>
* nsd/conn.c, tests/api/ns_conn.adp: fixed ns_conn
outputheaders as per bug #433676 submitted by Yon Derek
(yond).
2001-05-22 Scott S. Goodwin <scott@scottg.net>
* nsd/conn.c: changed Ns_ConnDriverContext in 4.x to return
the actual conn-specific, module-specific context back,
which is how it works in 3.x. For some reason this API call
was changed to always return NULL, but nsopenssl and
potentially other comm drivers need to get their conn-specific
info back.
2001-04-25 Dossy Shiobara <dossy@panoptic.com>
* Implemented [ns_localtime ?tz?] as per "[ #418890 ]
ns_localtime should accept timezone".
2001-03-15 Dossy Shiobara <dossy@panoptic.com>
* include/Makefile.win32 win32/*/Makefile: initial attempts
at Makefiles suitable for NMAKE for building on Win32
* include/ns.h: define typedef __int64 INT64 for Win32
2001-03-12 Scott S. Goodwin <scott@scottg.net>
* nsmain.c: Segmentation fault when using -g <group> flag:
line 294 should read Ns_GetGid(garg) instead of Ns_GetGid(optarg).
2001-03-12 Jim Davidson
Initial checkin of AOLserver 4.0 (beta), now supporting
vitual servers and (finally) removing supporting for Tcl
7.6.
2001-03-08 Kris Rehberg
*** AOLserver 3.3 RELEASED ***
2001-03-08 Jim Davidson
* Added NsTclFinalizeThread() at end of Tcl TLS cleanup to
finalize Tcl 8.x thread data. This fix was the last hurdle
for finalizing nsd8x.
2001-01-31 Kris Rehberg
* Makefile (MODULES): nsunix, nsvhr, and nsodbc moved to
the Module Collection.
2001-01-16 Jim Davidson
* Cleaned up sloppy use of the nsServer global wherever
it's used.
2001-01-04 Kris Rehberg
* nsd/tclmisc.c: Ticket 13090. ns_striphtml crashing-bug
in nsd8x fixed.
2000-12-14 Kris Rehberg
* tcl/http.tcl: Corrected typo _ns_ns_http_readable.
* nsd/dstring.c (Ns_DStringPrintf): Ticket 12765.
Ns_DStringPrintf uses vsnprintf instead of vsprintf with
specified buffer size. Thanks to "??".
* nsd/return.c (Ns_ConnConstructHeaders): Ticket 12764.
If-Modified-Since (304) works with keepalive now. Thanks
to Jim "??".
2000-12-13 Kris Rehberg
* include/Makefile.global: Builds with architecture-specific
optimization options. Auto-detects architecture for most
platforms. Auto-select compiler and Purify usage from
command line, e.g.:
gmake nativeme=1 (all non-free Unix)
gmake gccme=1 (some non-free Unix) gmake
PURIFY=/path/to/purify/executable (Solaris and Irix only)
* nssock/Makefile*: now installs The Right Things in The
Right Places.
* nsd/Makefile: nsd8x is the default AOLserver now (nsd
symlinks to nsd8x).
* nsd/sample-config.tcl: Added some tuning parameters for
easy reference.
2000-12-12 Kris Rehberg
* nsvhr/nsvhr.c (UDSProxy): More type changes.
* nslog/nslog.c (Ns_ModuleInit): pointer-to-function casted.
* nscp/nscp.c (GetLine): buf changed to char *; casted
AcceptProc.
2000-12-12 Jim Davidson
* nssock/sock.cpp: Fixed multiple-load problems, added
sndbuf, rcvbuf, sendwait, and recvwait options. Added
configurable backlog via Ns_SockListenEx. Fixed compile
bugs for ssl. Restructured the socket module to wait in
server busy situations instead of sending the server busy
message. Also, moved the graceful close burden to the
SockThread from the connection thread.
* thread/win32.cpp: Moved WinThread allocation to DllMain,
eliminating GetWinThread function. Also, disabled thread
cleanup for final thread to avoid any TLS cleanup callbacks
attempting to invoke code in unloaded libraries like Tcl.
Removed call to NsInitThread no longer needed. Switched to
rolling condition broadcast wakeup as in the sproc code.
More fixes for new Thread context model.
* thread/tls.c: Changed NsLock API's to return 1/0 instead
of NS_OK/NS_TIMEOUT and more use of Ns_MasterLock to keep
things simple.
* thread/thread.c: Changed thread enum to return Ns_Thread,
not Ns_Thread pointer which didn't make much sense. Updated
"ns_info pools" command to reflect change. Fixed bugs with
Ns_ThreadEnum and pool counters. Update of the Ns_Pool API
to support more stats gathering available via new Ns_PoolStats
API. Remove Thread->etime and NsPool API's. Moved sprintf
of default thread name from NsThreadMain to NsInitThread
under protection of threads lock. Added comment for
NsInitThread. More fixes for new Thread context model.
Updated sproc.cpp code for new Thread management and removed
the wait for thread startup which shouldn't be needed.
* thread/test.c: Cleaned up code a bit to quiet compiler.
Better test for PTHREAD_TEST. Fixed undefined var bug for
sproc. Added some comments, a native pthread test, and a
recursive stack checker.
* thread/tcl8x.c: Added Tcl_JoinThread for benefit of
Tcl8.4.
* thread/sproc.cpp: Changed NsLock API's to return 1/0
instead of NS_OK/NS_TIMEOUT and more use of Ns_MasterLock
to keep things simple. Fixed some comment bugs, update
thrPtr->tid after fork. Added call the NsInitThread. Updated
sproc.cpp code for new Thread management and removed the
wait for thread startup which shouldn't be needed.
* thread/pthread.cpp: Changed NsLock API's to return 1/0
instead of NS_OK/NS_TIMEOUT and more use of Ns_MasterLock
to keep things simple. Fixed bug of not setting the tid
correctly. Added call the NsInitThread.
* thread/pool.c: Added Ns_PoolEnum to get at pool stats as
with mutexes and threads, removing the old Ns_PoolStats
API's and updating the "ns_info pools" command. Fixed bugs
with Ns_ThreadEnum and pool counters. Update of the Ns_Pool
API to support more stats gathering available via new
Ns_PoolStats API. Removed <mutex.h> for sgi which shouldn't
have been there. Removed the sbrk() code for now, was
crashing SGI (probably not thread safe). Use sbrk() on Unix
instead of malloc to avoid any malloc overhead or contention.
Reduced the zippy allocator page size to 16k from 64k.
* thread/pool.c, thread.c, sproc.cpp: Re-structured management
of the Thread context to better support threads created
without Ns_ThreadCreate (e.g., Java VM threads).
* thread/mutex.c: Changed NsLock API's to return 1/0 instead
of NS_OK/NS_TIMEOUT and more use of Ns_MasterLock to keep
things simple.
* thread/cs.c, memory.c, mutex.c, pool.c, pthread.cpp,
reentrant.c, rwlock.c, sema.c, sproc.cpp, tcl8x.c, test.c,
thread.c, win32.cpp: Restructured the thread interfaces,
moving the master lock to the platform interface code,
integrating the zippy allocator with Ns_Pool/Ns_ThreadAlloc
and use of a new simple direct allocator for all thread
objects.
* win32/nsthread/nsthread.dsp: Removed master.c and
oldpools.c.
* nsd/unix.c: Made ns_eval command disabled by default to
avoid using SIGUSR2.
* nsd/tclthread.c: Changed SETOBJ macro to SetObj function
which no longer sprintf's directly into interp->result.
* nsd/tclmisc.c: Added Ns_PoolEnum to get at pool stats as
with mutexes and threads, removing the old Ns_PoolStats
API's and updating the "ns_info pools" command. Changed
thread enum to return Ns_Thread, not Ns_Thread pointer
which didn't make much sense. Updated "ns_info pools"
command to reflect change. Added more info for "ns_info
pools". Added "ns_info pools" command to dump memory pool
stats.
* nsd/tclinit.c: Added nsconf.quiet and nsconf.startuptimeout.
Made ns_eval command disabled by default to avoid using
SIGUSR2. Added nsConfQuiet flag to quiet down the startup
messages with the -q flag.
* nsd/sock.c: Added Ns_SockListenEx.
* nsd/serv.c: Ensured the conn thread name was set first.
Added Ns_RegisterAtReady callbacks for indicating server
no longer busy.
* nsd/sched.c, nsmain.c, serv.c, sockcallback.c: Added code
to wait for conn thread, sock callback, and sched idle at
startup to help alleviate code start problems.
* nsd/nsmain.c: Shuffled initialization to ensure command
line args are read before calling any Ns API's, ensuring
zippy malloc can be set if needed.
* nsd/nsconf.c: Added nsconf.quiet and nsconf.startuptimeout.
Made ns_eval command disabled by default to avoid using
SIGUSR2.
* nsd/dstring.c: Remove unused vars. Uses ns_realloc to
grow strings and maintains dstring stack in the staticSpace
instead of the *addr pointer for compatibility with Tcl
dstrings.
* nsd/callbacks.c: Added Ns_RegisterAtReady callbacks for
indicating server no longer busy.
* nsd/binder.c: Added Ns_SockListenEx.
2000-12-12 Kris Rehberg
* nsvhr/nsvhr.c (VHRProc): Matches hostnames regardless of
case.
* nssock: Supports Rainbow CryptoSwift SSL accelerators
(compile-time option; requires the Swift SDK from).
* nsd/nsmain.c (Ns_Main): Changed order of some config
default initialization. Config options cleaned up a lot.
Usage message very less glib. SUNWspro dumped core on
usage message due to nsconf.argv0 quigglyness.
2000-10-20 Kris Rehberg
*** AOLserver 3.2 RELEASED ***
2000-10-20 Jim Davidson
* win/tclWinSock.c: Fixed deadlock in sockets init code.
* nsd/nswin32.c: Fixed service install code to allow long
pathnames with spaces. Added/use ns_pipe which set's
close-on-exec like ns_sockpair.
2000-10-17 Kris Rehberg
* nssock/sock.cpp: extra padding on Server Busy message to
defeat MSIE friendly error messages.
* nsd/nsconf.h: All configuration option defaults have been
moved to nsconf.h as #defines.
* Makefile (install): Tcl library for nsd8x is now installed
into $(PREFIX)/lib/tcl8.3.
* tcl/http.tcl (ns_httpopen): Host:port is now sent to
remote host if != 80. Suggested by Jerry Asher.
* tcl/fastpath.tcl (_ns_dirlist): All kinds of Win32
pathnames should now be working. Thanks to Eric Klein.
* nsd/return.c (Ns_ConnReturnNotice): New options
"errorminsize", to pad error messages to defeat MSIE friendly
errors (fix suggested by ArsDigita) and "noticedetail" to
return more detailed information on notice pages.
* nslog/nslog.c: suppressquery option added to suppress
logging of query data.
* nslog/nslog.c: LogExtendedHEaders option added. Contributed
by ArsDigita.
* nsd/tclfile.c: Input string to mktemp is copied, because
mktemp edits the string in-place and that's generally a
bad thing to do with argv's. Contributed by ArsDigita.
* nsd/tclnsshare.cpp (ShareTraceProc): Patch to tclnsshare.cpp
to avoid race conditions if the shared value is a list.
Contributed by ArsDigita.
* tcl/http.tcl (ns_httpopen): CRLF now returned in ns_httpopen.
Contributed by ArsDigita.
* tcl8.3.2/generic/tclCmdIL.c: Nonsense case of lsorting
a list with length <= 0 caused a memory leak. Fixed.
Contributed by ArsDigita.
* nsd/adpfancy.c: We now use the Arsdigita version of
adpfancy. Contributed by ArsDigita.
* nsd/adp.c: Sundry ArsDigita changes.
2000-10-16 Kris Rehberg
* tcl/init.tcl: Initialize errorCode and errorInfo like
tclsh does. From ArsDigita.
* nsd/nsd.h, nsd/tclcmds.c, nsd/tclvar.c: nsv_names Tcl
command lists names of nsv's in memory.
* tcl8.3.2: The complete Tcl 8.x distributions are now
included. They aren't installed with AOLserver's "gmake
install", but you can install them manually if you want to
use them for the i18n encodings and stuff like that. It
will install into the "lib/tcl8.3" directory of the binary
distribution with AOLserver 3.3 and later.
* nsd/nsmain.c (Ns_Main): Had to move Ns_ThreadSetName
below the stdin/stdout/stderr reassignment to fix a fd
problem with running nsd on Irix in "installed" or "daemon"
mode that would prevent the server from starting up. Sigh.
(Ns_Main): Took out little note about -k|-K being deprecated.
2000-10-13 Kris Rehberg
* nsd/nsmain.c (Ns_Main): gid of the specified user is set even if
it's not specified.
(UsageError): -K and -k give a "deprecated" warning.
(Ns_Main): -f gives a "deprecated" warning.
* nsd/binder.c (PreBind): Didn't really tell us if it was
successful at pre-binding. Helpful to know if you're
wondering what happened to that port you wanted to pre-bind.
(Binder): backlog variables (2) initialized to nsconf.backlog.
* nssock/sock.cpp, nsd/return.c: Made an attempt at
standardizing the error codes and error page content.
2000-10-13 Jim Davidson
* sproc.cpp: Fixed Wakeup() error message and update child's
sproc pid after fork.
* nsd/random.c: Put back log message when generating seeds.
* nsd/nsconf.c: Fixed memory overwrite bug in stats and
increased the default buffer value.
* nsd/keepalive.c: Fixed array overwrite with maxkeep=0
bug. Contributed by ArsDigita.
* nsd/tclkeylist.c: A more modern version added that's
compatible with Tcl 8.3.2 (nsd8x).
* nsd/stamp.c: Forces the build date reported by AOLserver
to be absolutely the last possible moment before the link
step happens, not just the last time nsmain.c was built.
* nsd/binder.c: New option "-b" to prebind ports as root
(but not listen on them). This allows AOLserver to start
up on MacOS X on ports 80 and 443 like this: "nsd ..blah..
-b 10.0.0.1:80".
* nssock/: Building nsssl is much less of a debacle and
doesn't rebuild itself three times anymore.
* various: fork() calls in all kinds of code were changed
to use ns_fork. ns_fork now lives in the thread library
(thread/ directory).
* tcl8.3.2/generic/tclIO.c: Fixed memory leak that leaks
around 112 bytes each time a file descriptor is closed.
Thanks to Rob Mayoff for finding this and proposing a
solution.
2000-10-09 Kris Rehberg
* sample-config.tcl: nsd.tcl is now sample-config.tcl so
that existing users can look at the new reference configuration.
* nsd/nsmain.c (Ns_InfoNameOfExecutable): new function just
returns nsconf.nsd which is determined elsewhere.
* nscp/nscp.c (Login): Tells you lots of harmless info
about the machine once you log in. Also, nscp does not
run unless configuration is explicitly set
* nsd/nsmain.c: Some typo or other.
* General: Files were re-arranged and some were renamed.
The sample SSL key/cert files are sample-certfile,
sample-keyfile. The nsd.tcl is now called sample-config.tcl
(so that existing installations always have a current
reference copy of the configuration). Other minor changes.
* tests/: Moved from its hiding place in scripts/test.
Install them with "gmake install-tests".
* nsd/tclxkeylist.c, nsd/tclcmds.c, nsd/Makefile: Re-added
TclX keyl* commands that were in AOLserver 2.x. These are
inferior to ns_set which is why they were left out in the
first place.
2000-10-04 Jim Davidson
* binder.c: Set close-on-exec on received fd from binder.
* sock.c: Removed cthread errno API's, Mac OS X now has
thread-safe errno.
* nsd/nsmain.c, include/Makefile.global, nsd/nsthread.h,
nspd/main.c, nsunix/nsunix.c, nsvhr/nsvhr.c, thread/Makefile,
thread/osthread, thread/reentrant.c, thread/signal.c:
Updates for Mac OS X. Use MACOSX instead of APPLE; use
HAVE_BSDSETPGRP, HAVE_CMMSG, use pthreads instead of
cthreads.
* nssock/sock.c: Removed setting bufsize to uninitialized
value on ssl.
* include/ns.h: Removed Ns_CacheTimedGetValue which was an
odd interface not used anywhere.
* nsd/nsd.h: Update to version 3.11.
* tcl/namespace.tcl: Added namespace export to init script.
* thread/pthread.cpp: Stopped using pthread_once as it
appears to require a lock.
2000-10-04 Kris Rehberg
* win32/nsssl/nsssl.dsp: nsssl project for win32.
* win32/aolserver.dsw: main installation keeps DLL's as
DLL's now.
* scripts/nsd.tcl: shared library extension is now
platform-dependent
* nssock/ssltcl.c: Changed name of ReadFile adn WriteFile
to avoid Win32 naming conflicts.
2000-09-28 Kris Rehberg
* scripts/tests/nstelemetry.adp: added "Expires: now" header
to ensure it gets run each time it's visitted.
* nsd/serv.c (NsConnArgProc): Race condition when threads
exit while [ns_info threads] is run; arg can be NULL. Seen
mostly by people who regularly visit nstelemetry.adp.
(AppendConn): same thing but with connPtr. This may be a
losing battle. It appears to work on a busy Irix server,
so I'm declaring victory for now.
2000-09-28 Jim Davidson
* nssock/sock.c: Fixed bufferred read code in SockRead,
resulting in a big performance boost and system load
reduction. Special thanks to Zachary Girouard.
2000-09-05 Kris Rehberg
*** AOLserver 3.1 Released ***
2000-09-05 (various: Jerry Asher, Jim Davidson, "Dossy," Curtis Galloway,
Scott S. Goodwin, Rob Mayoff, Kris Rehberg)
* thread/win32.cpp: Sets thread stack size as on other
platforms.
* thread/thread.c: NULL out thread arg at exit to avoid
Ns_ThreadEnum checking arg info for possibly deallocated
context as seen in ns_info threads. Also, moved read of
firstPtr in Ns_ThreadEnum inside lock. Added Ns_ThreadCreate2
in thread.c needed for upgrade to Tcl 8.3.1 in tcl8x.c
* thread/pthread.cpp: ETIME bug work around not causes
wakeup in Ns_CondWait and Ns_CondTimeWait instead of waiting
again. This is more conservative and should avoid problems
some have had with threads missing wakeup.
* thread/pool.c: Added a simple 1-byte range check to -z
allocator.
* thread/Makefile: Added dependency for osthread.o to
Makefile.
* tcl/namespace.tcl: Added namespace export to init script.
* nsvhr/nsvhr.c: Switched to Ns_WriteConn in TimedSockDump
to ensure all data was sent.
* nssock(nsssl): SSL module includes a fake 40-bit/512-bit
export-grade SSL keyfile.pem and certfile.pem for immediate
use on installation. Adjusted for use with BSAFE 4 and 5.
* nspd: Library now installed to binary distribution.
* nsd/tclsock.c: Fixed crash bug in error message in
ns_socknread.
* nsd/tclcmds.c: Added ns_adp_registertag command as
documented.
* nsd/serv.c: Added missing break for unauthorized case in
ConnRun.
* nsd/random.c: Fixed deadlock between Ns_DRand/Ns_GenSeeds.
* nsd/nsmain.c: Fixed some message formatting problems.
* nsd/mimetypes.c: Added .png type, "image/png".
* nsd/dbtcl.c: Removed unused variables in GetCsvCmd. Use
a dstring to create the column list instead of incrementally
setting the output variable with Tcl_SetVar. This was
necessary to avoid conflicting definitions of the needed
TCL_ flags between 7.6 and 8.x.
* nsd/dbinit.c: MOdified current per-thread handle count
to use a single TLS slot instead of a slot per pool.
* nsd/tclinit.c,adp.c,conn.c: The use of thread-local
storage (Tls) is now self-initializing in the conn, ADP,
Tcl, etc. This allows ns_conn commands to be used outside
a connection thread as well as other uses of Tls where it
may not be ready for use.
* nscp/nscp.c: Password non-echo code confuses Win32 and
some free Unix telnet clients so it has been disabled by
default for now, though it can be enabled by setting
"echopassword" in the nscp module section of nsd.tcl.
2000-08-21 Kris Rehberg
* nscp/nscp.c: Makes some attempt to recognize and handle
telnet IAC codes like CTRL-C and CTRL-D to force a logout.
This implementation of the telnet protocol is dirt-cheap,
so only standard Unix telnet is supported. On Win32, IAC
handling is completely disabled because the client is too
chatty with its IAC codes.
2000-08-20 Kris Rehberg
* nsftp, nspostgres, nssolid, nssybpd moved to $TOP level.
2000-08-17 Jim Davidson
* nsd/dbtcl: Removed unused variables in GetCsvCmd.
* nsd/adp.c: Fixed bug of not truncating output buffer when
an error was thrown during an ns_adp_parse. Fix suggested
by Rob Mayoff.
* tcl7.6 and tcl8.2.3: Switched to blocking Tcl_WaitPid to
avoid zombies as suggested by Rob Mayoff.
* thread: NULL out thread arg at exit to avoid Ns_ThreadEnum
checking arg info for possibly deallocated context as seen
in ns_info threads. Also, moved read of firstPtr in
Ns_ThreadEnum inside lock.
2000-08-17 Kris Rehberg
* nssock/sock.c (SockThread): warning sent to log when
Server Busy is returned.
* All the Makefiles should be in line with each other.
Typing "gmake", "gmake install" and "gmake clean" should
work in any directory. NSHOME is paid attention to by all
Makefiles.
* nsd: Ns_Log and Ns_Fatal statements are hopefully more
standardized and more useful to admins and developers.
* Irix now builds as -o32 using the native compiler by
default. See Makefile.global on how to change.
2000-08-15 Kris Rehberg
* include/Makefile.global (INSTLOG): should have pointed
to $(INST)/lib, not $(INST)/modules/lib.
* Makefile: nsunix resurrected. All modules are built.
If a module is missing a library, it is not built, but it
won't stop the AOLserver build process (no error is thrown).
The build will continue with the next module.
* nsftp: guesses if you have TCP_WRAPPERS available.
* nsext: Ten guesses why $(NSHOME)/include/nsextmsg.h was
duplicated here.
* nssybpd: Hopefully, the log statements will be easier to
understand by both admins and developers. It's still messy
since it uses syslog. Makefile redone to use standard
AOLserver rules. RPATH is used a little more intelligently.
Removed files that had no business living there.
* include/Makefile.global: Took stab at RPATH support on
Solaris to perhaps remove the need for LD_LIBRARY_PATH on
an intelligenly-administered system. New rule for libnspd.a.
2000-08-14 Kris Rehberg
* Makefile: nsvhr has been resurrected and enjoys our full
support.
* nsexample/Makefile: The include at the bottom wasn't using
$(NSHOME).
2000-08-14 Jim Davidson
* Tcl 8.x library upgraded to tcl8.3.2.
* thread/pool.c: A spiffy range-checker added to the Zippy
(-z) memory allocator.
2000-08-11 Kris Rehberg
* nsvhr/nsvhr.c: Always add "Connection: close" to the
request line to satisfy HTTP 1.1 RFC -- this would break
MSIE in HTTP 1.1 mode. HTTP_EOL of "\r\n" used on all
request lines for stupid web servers on the other end.
Protocol "tcp" added as synonym of "http" for old-time Unix
heads. Lots of folks lended a hand on this one -- Satyam
Priyadarshy, Jerry Asher, Kriston Rehberg, and special
thanks to Wanda G. at AOL for adding a CNAME in DNS so
quickly.
2000-08-09 Kris Rehberg
* nsd/serv.c: A whole lot less chatty about conns starting
and exiting. If you want to see them, turn on the Debug
flag.
* doc/*: lots of updates. Title page extremely simplified.
SSL docs updated. Release notes updated. NSV docs corrected
(thanks to Todd Levy.
2000-08-09 Jim Davidson
* tcl7.6/generic/tclFHandle.c: Removed needed fileTable
which could result in crashes when fd's where reused quickly
[fixes a rare multiple-exec crashing bug in nsd76 --kris].
* thread/tcl8x.c: Added a wrapper startup for Tcl_CreateThread
for the benefit of Win32.
* nsd/log.c: Removed severityRank array.
* nsd/tclmisc.c: Fixed bug with ns_info pid. [I can't code --kris]
* nsd: keepalive.c,nsmain.c,sched.c,serv.c: Re-ordered
shutdowns to ensure connection threads are stopped before
other shutdowns begin (e.g., sched, sockcallback).
* tcl8.3.1 replaces tcl8.3.0. README.AOLSERVER added to
tcl8.3.1 directory. Original copies of changed are named
*.orig.
* include/Makefile.global: Build environment now uses gcc
-shared -nostartfiles as the default LDSO.
* nsthread/thread.c: Added Ns_ThreadCreate2 with extra
flags argument used by Tcl_CreateThread to create a detached
thread.
2000-08-06 Scott S. Goodwin
* nsd/log.c: Segmentation fault was occuring when writing
to the log file because file pointer was being assigned to
incorrectly - it wasn't NULL and it wasn't a valid address
within processes memory. Fixed.
2000-08-06 Scott S. Goodwin
* nssock: You can now compile with BSAFE versions 4 and 5.
You'll need to specify the path to your BSAFE libaries and
the BSAFE version in the nssock/Makefile before compiling.
If you don't have BSAFE and want to compile without SSL at
all, edit the toplevel Makefile and take out all the "SSL=1"
text. The files changed were nssock/Makefile and
nssock/t_stdlib.c.
2000-08-02 Kris Rehberg
* Build process is a little more rule-oriented. The cleaning
rules "distclean" and "clobber" were removed. The Tcl
libraries are always distcleaned when "gmake clean" is
invoked. Rules that can be used as dependencies were made
for libnsthread and the Tcl libraries -- their names are
"libnsthread," "libtcl76," and "libtcl8x," respectively.
PREFIX is now used as the installation directory (along
with INST), so the more familiar "gmake install
PREFIX=/usr/local/aolserver" will work. Additionally,
gmaking in a subdirectory with dependencies now works.
* nsd/log.c: The sourge of modlog has been removed. All
code included with AOLserver that used Ns_ModLog now doesn't.
Many log statements are now hopefully more standardized.
This will be a continuing improvement over the next several
updates. I would like to use gcc's __FUNCTION__ macro but
it doesn't work on native compilers, but we may start using
__LINE__ and __FILE__ instead or replace Ns_Log with a
smart macro that takes care of all this stuff for us.
* nsd/tclmisc.c (NsTclInfoCmd): ns_info pid added to return
the process id.
2000-08-01 Kris Rehberg
* nsd/adp.c (Ns_AdpRequest): The enableexpire option was
putting an Expires header even if it already existed.
* nsd/return.c (Ns_ConnReturnNotice): Yikes, /face should
have been /font. No more fonts, colors, etc, on default
notice pages.
* nsd/tclsock.c (NsTclSockOpenCmd): Removed spurious Ns_Log
Notice from ns_sockopen.
* tcl/form.tcl (ns_getform): MSIE presents the wrong stuff
to the server when a multipart/formdata POST is redirected.
Workaround contributed by Joseph Bank.
* tcl/fastpath.tcl (_ns_dirlist): base href removed --
links are now fully-qualified.
* Makefile (install): include and lib dirs are now included
in binary distribution.
* tcl/http.tcl (_ns_http_gets): \n replaced by \r in all
but _ns_http_gets so that arbitrary headers get set correctly.
* tcl7.6/generic/tclPosixStr.c (Tcl_SignalMsg): Patch to
Tcl 7.6 for Red Hat on SPARC architectures. Contributed
by Mike Chan.
2000-07-13 Kris Rehberg
* scripts/nsd.tcl: nssslmodule names the nsssl/nsssle
binary's filename. nscp_port tells nscp what port to
listen.
* nssock: nssock.c renamed sock.c, SSL support has been
merged back with nssock so that both nsssl and nssock use
identical socket code.
* nsssl2: directory removed; nsssl is in the nssock directory
now.
2000-05-09 Kris Rehberg
* Re-added doc directory which has had the online docs
removed.
2000-05-02 Kris Rehberg
* Makefile, include/Makefile.global, include/Makefile.module,
nsexample/Makefile: Now uses NSHOME variable to locate
AOLserver. NSHOME is automatically figured out in the
top-level Makefile and all the lower Makefiles still use
relative directory paths. The intention of NSHOME is for
modules that do NOT live in the AOLserver source directory
tree. The nsexample/Makefile explains how this works.
* nsftp module added. Contributed by Eric O'Laughlen.
2000-04-12 Kris Rehberg
*** AOLserver 3.0 FINAL Released *** | https://sources.debian.org/src/aolserver4/4.0.10-3/ChangeLog/ | CC-MAIN-2020-34 | en | refinedweb |
import "k8s.io/apiserver/pkg/storage/storagebackend/factory"
func CreateHealthCheck(c storagebackend.Config) (func() error, error)
CreateHealthCheck creates a healthcheck function based on given config.
DestroyFunc is to destroy any resources used by the storage returned in Create() together.
func Create(c storagebackend.Config) (storage.Interface, DestroyFunc, error)
Create creates a storage backend based on given config.
Package factory imports 20 packages (graph) and is imported by 11 packages. Updated 2019-10-31. Refresh now. Tools for package owners. | https://godoc.org/k8s.io/apiserver/pkg/storage/storagebackend/factory | CC-MAIN-2019-51 | en | refinedweb |
Howdy all,
I have a very obscure (and minor) colormapping issue which I would like to discuss. I am writing a workaround and the question is whether or not this is worth changing the base matplotlib distribution. The issue applies to any code that uses colormapping such as matshow or imshow. I am going to write the change and it is up to the user community whether anyone else in the world cares about this.
In color.py::LinearSegmentedColormap.__call__
The code that determines the colormap value in the look up table is
xa = (xa *(self.N-1)).astype(Int)
rgba = zeros(xa.shape+(4,), Float)
rgba[...,0] = take(self._red_lut, xa)
rgba[...,1] = take(self._green_lut, xa)
rgba[...,2] = take(self._blue_lut, xa)
I am using colormaps for thresholding data. If the normalized image value is less than some threshold I plot one color, if it is above that threshold, I plot a second color. All images produced this way are two colors. This is just what I do, but the issue is always there for thresholding.
Here's the issue. The code line xa = (xa *(self.N-1)).astype(Int) simply truncates the data, in essence taking the floor of xa, the reason why this matters is that value always get rounded down, so intensities above the threshold all get mapped to the threshold value. The error is small and dependent only on the quantization of the colormap, normally N=256. Nonetheless, there are times, like when the threshold is 0 that the rounded down values are visible and should not be.
The best way to make thresholds get rid of this problem is to use the ceiling function. So the code would read
xa = ceil(xa *(self.N-1)).astype(Int)
Then intensities are rounded up, which is safe for thresholding. Note that the original code is not wrong. There are circumstance when it does the correct thing, even with thresholding. The new line also takes (not much) longer because of the ceil function.
There is a fudge involving only user code, which would be to negate the image data and reverse the colormap, but that is not particularly pretty.
My personal suggestion is to include a flag in the declaration of the colormap:
def __init__(self, name, segmentdata, N=256, ceiling=False):
self.ceiling = ceiling
then in the __call__ routine:
if self.ceiling:
xa = ceil(xa *(self.N-1)).astype(Int)
else:
xa = (xa *(self.N-1)).astype(Int)
Let me know what you think.
Danny | https://discourse.matplotlib.org/t/obscure-colormapping-issue-related-to-quantization/3190 | CC-MAIN-2019-51 | en | refinedweb |
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How to write a security integration module for Ansible | Opensource.com
How to write a security integration module for Ansible
Ansible automation offers a lot of potential for the information security industry. Learn how to take advantage of it in this summary of an AnsibleFest 2019 talk.
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Ansible is a radically simple IT automation platform that makes your applications and systems easier to deploy. It allows you to avoid writing scripts or custom code to deploy and update your applications, systems, and various classifications of network-attached devices. Ansible allows you to automate in a language that approaches plain English with no agents to install on remote systems and uses native protocols based on device type—such as SSH for Unix-style operating systems, WinRM for Windows systems, REST APIs (httpapi) for REST API appliances, and many more.
Background
At AnsibleFest 2019, my colleague Sumit Jaiswal and I gave a talk, titled "Ansible development deep dive: How to write a security integration module and collection for Ansible," about something that we have been working on. This article recaps the finer points of our talk; I hope it will highlight the potential of what Ansible is—and can be capable of—in the realm of information security automation.A lot of this started with my colleague Massimo Ferrari's statement that "Ansible automation can be the lingua franca to integrate and orchestrate the many security platforms spread across different domains." We spent a lot of time mulling this over; it may be obvious to DevOps and automation professionals who've discovered the power of Ansible, but infosec doesn't have similar tools that target the industry's problems in the same way. Therefore, Ferrari's statement offers a lot of potential for the infosec industry.
In this article, I'll summarize two major points we highlighted in our AnsbileFest 2019 talk:
- Ansible recommended development practices
- Classify what you're integrating with and how you connect to it (API or CLI?)
Ansible recommended development practices
The Ansible engineering team likes to never write the words "best practice," because we can't possibly know what's best for you in your specific situation. You are the expert on topics as they apply to your unique environment and requirements. However, we can provide recommendations, which I'll outline from the perspective of an Ansible module developer.
Modules
Modules are user-focused and self-contained. This mostly means that the code contained in your module should be self-contained within your module or in a module_util. The latter is what allows us to share code between modules, but everything must be as self-contained as possible, as we don't want to introduce too many external dependencies. We also want each module to perform some sort of state management. Each module should be idempotent, which basically means "inflict change if needed, otherwise, do not." A module should not attempt to contain a workflow (that's what playbooks are for), and we want to leave that up to the user. Modules shouldn't attempt to "do too much," such that you have one massive module that takes 100 arguments and, based on values provided by the user, performs wildly different actions on the target device.
An example of what we generally want to avoid could go something like this:
- name: Create a virtual machine
some_module:
thing_to_do: "create_virtual_machine"
name: "bobs_awesome_vm"
storage_size: 100G
ram: 24G
vcpus: 4
- name: Create a virtual storage volume
some_module:
thing_to_do: "create_virtual_storage_vol"
name: "bobs_awesome_storage"
storage_size: 1000G
lun_id: 12
In this example, the fictitious some_module is performing completely disjointed actions based on the value of thing_to_do. This is not a discrete, self-contained unit of work from the perspective of an Ansible module. These should be two separate modules that could even share code on the backend through a custom module_util (if that makes the developer's life easier). Either way, they should be separate modules so the user can easily define, read, and understand the task as written. As a developer, you want to make the module's interaction user-focused.
Another aspect of being user-focused is that the user should not need any knowledge of the destination API in order to use the module effectively. The module should provide useful defaults, documentation, and examples that allow users to pick their own automation path.
Collections
Ansible collections are a relatively new concept, but they are generally seen as the future for Ansible content of all shapes and sizes. They allow Ansible content, such as modules, module_utils, plugins of all kinds, roles, docs, tests, playbooks, and whatever the community dreams up next, to exist as a cohesive unit to be tested, verified, and distributed as an entity. What's more (and this is its real advantage for developers) is that it decouples the content from the Ansible Core runtime. This allows Ansible content to be lifecycle-managed separately from Ansible itself, meaning it can be released as often or as infrequently as the content author or maintainer desires. No longer will new features have to wait six months for the next Ansible release. The collection authors can release as often as they desire.
Collections are meant to be a simple progression into a brave new world where the Ansible Core execution engine is symbolically similar to CPython. Ansible collections are symbolically similar to Python modules found on PyPI. Ansible Galaxy is symbolically similar to PyPI as the de facto distribution mechanism.
From a developer standpoint, you simply need to drop your files in the correct location and update any custom module_utils Python import paths. From a user perspective, you just need to add the collection namespace and name to the play or block that intends to use that content.
Classify what you're integrating with and how you connect to it
In the security realm, appliance devices or software that is meant to be used like an appliance (network devices, embedded systems, and so on) sometimes present the administrator both an application programming interface (API) and a command-line interface (CLI). As a module developer, you must make some decisions in service of ease of development, maintainability of code, and, ultimately, consistent user experience.
CLI
If you are potentially going to wrap a CLI, ask yourself whether that CLI offers a consistent interface with output you can reasonably and consistently parse. Beyond that, does the CLI offer the ability to formulate idempotent transactions? While the majority of CLIs offer get and set types of transactions (especially on Unix/Linux systems), some of them do not, and this is something module authors need to consider.
When considering CLI implementations with network or embedded devices that have a standard CLI but don't offer a traditional Unix shell, you should look into implementing a cliconf plugin. This type of plugin enables your users to interact with appliances or embedded devices in a way that's natural to the seasoned Ansible user and beginner alike. Alternatively, should you find yourself with a device that allows you to execute local Python code (local to the device or system itself; a "managed host" in Ansible terminology), then consider the run_command module_util. The latter situation is effectively just a traditional module development workflow, as it would be for a traditional GNU/Linux distribution.
API
If the technology you are attempting to integrate with offers an API, determine whether that API is a local on-system API (local to the remote "managed host" system) or a remote API such as a REST API?
In the event you find yourself with a local Python API and it's advantageous to use it instead of the REST API (in the event both are available), this situation is effectively the same as a traditional module development workflow in a GNU/Linux distribution.
However, if the only option is a REST API, or if the available REST API is determined to be the best option, then writing an httpapi connection plugin is best for general ease of implementation, maintenance, and handling things like AuthN, AuthZ, sessions, and so on. It also offers an idiomatic pattern for talking to these types of devices, even though they have a considerably different means of communication than most others that Ansible works with.
An example to illustrate this point is probably common to anyone who has automated a web service with a module that doesn't provide an httpapi connection plugin. Typically in these scenarios, the play, block, or task must be run against localhost, and the various information for the connection to the web service must be passed to each invocation of the module for each task.
---
- name: talk to foo device
hosts: localhost
tasks:
- name: do something
foo_device_do_thing:
url: foo.example.com
username: "{{ foo_device_username }}"
passwd: "{{ foo_device_password }}"
validate_certs: true
thing_state: present
some_param: bar
If this module had been implemented against an httpapi connection plugin instead, then the various connection-specific parameters would be host variables or group variables and wouldn't have to be carried around at the task level in playbooks.
Here's an inventory entry to handle the AuthN/AuthZ connection for all Ansible modules, written against the httpapi connection plugin. It also performs session handling for increased performance:
[foo_devices]
foo.example.com
[foo_devices:vars]
ansible_network_os=foo_device
ansible_user=foo_device_username
ansible_httpapi_pass=foo_device_password
ansible_httpapi_validate_certs=true
This playbook would be considerably more idiomatic. The foo_devices are a first-class device type and host pattern for the playbook.
---
- name: talk to foo device
hosts: foo_devices
tasks:
- name: do something
foo_device_do_thing:
thing_state: present
some_param: bar
A playbook has to define information for every task, so imagine one that has 20 or 100 tasks. The overhead would be considerable. This doesn't feel much like directly automating the hosts defined in the host field. However, the httpapi connection plugin negates the need to define the connection information over and over, and it also talks natively to devices over a REST API, just as you would on a Linux system over SSH in a playbook.
Something to note about httpapi connection plugins is that, even though the user defines hosts, groups, host vars, and group vars, just in like a traditional Unix/Linux or Windows-managed host, these modules actually execute against the localhost (the "control host" in Ansible nomenclature). This is something to keep in mind when you're developing.
What the what?
If you're new to Ansible module development, this might seem like a lot to take in at once. To be fair, it is. However, as you become more seasoned in the finer points of Ansible module development for a wide array of device types and technology solution classifications, the motivation for different development strategies starts to make sense. Some device classifications have idiosyncrasies, and this model helps Ansible developers and users deal with those in a consistent and predictable way.
Wrapping up
If you have questions about Ansible module development models, feel free to reach out through the vibrant Ansible Community, and more specifically, the Ansible Security Automation Working Group.
Comment now | https://opensource.com/article/19/12/security-ansible-module | CC-MAIN-2019-51 | en | refinedweb |
Coding, people believed, was an activity hackers did alone. While that might have been true in the past, the world is changing. New programmers come online every day and they want to effortlessly work and interact with others while writing code. Yet collaborative coding environments have remained troublesome to setup.
Last year we launched Multiplayer, our real-time collaborative system, in beta. We’ve learned a lot since then. We’ve learned that while real-time coding is useful and fun, asynchronous collaboration is important for users working on long-term projects (which people are increasingly doing on Repl.it). We’ve learned that Multiplayer needs to be a core feature of the product -- not something you “turn on.” This meant a redesign of our core protocol and infrastructure to make it collaborative at heart.
Repl.it is now natively Multiplayer: Collaborators can code together at the same time or asynchronously, real time editing is more robust, and every IDE feature works seamlessly in a collaborative setting.
Protocol Changes & Operational Transformation
The major challenge in making Repl.it collaborative at heart was adapting all our existing functionality to work seamlessly in a multiplayer environment. For a very long time we’ve gotten away with keeping the protocol very simple. Modeled after the Read-Eval-Print-Loop with a strict state machine. Only one action could be processed at a time and had to run to completion.
As features were added we ended up with something like a Read-(eval|format|lint|write file|etc.)-Print-Loop. This lead to some unititive behavior: what happens if someone could format code while someone else was in the middle of debugging? In a multiplayer setting, these issues compounded making the experience buggy and slow at times.
Enter Collaborative Development Protocol (CDP): A scalable service-oriented approach for remote development and collaboration. It starts with channels -- every function is an isolated channel. Want to write to a file? You open a channel. Want to eval? You open a channel. Want to install a package? You do it on the package manager channel. Even opening a channel occurs on a control channel everyone starts with. With channels as the core concept, collaboration is built right into the design. To share a resource, clients need only connect to the same channel.
Here is how'd you implement a simple REPL using CDP:
import CDP from '@replit/collab_dev_proto'; const client = CDP.connect({ language: 'python' }); // channel 0 is the control channel const control = client.getChannel(0); const evaler = await control.send({ openChannel: { name: 'evaler', service: 'eval', } }); evaler.on('command', command => { if (command.type === 'state') { console.log('Running ', command.status ? 'started' : 'stopped'); } if (command.type === 'output') { console.log('> ', command.output); } }) const code = window.prompt('type your code') const response = await evaler.send({ eval: code, }); if (response.type === 'error') { console.error(response.error) } else { console.log('=> ', response.result); }
Messages concerning everyone are shared by broadcast. Multiple clients can attach to a channel by using a pre-decided upon channel name, where everyone can read/write. For example, a client can send an eval command to the “evaler” and all other clients will get a message that evaling has started, and then everyone receives the same output.
Finally, and perhaps most crucially, file changes are always communicated via Operational Transformation. Operational Transformation (OT) was designed to handle real-time collaborative text document updates, and if Repl.it was going to be collaborative at heart, it needed to speak OT everywhere there was text to update.
File Watching & File Changes
In the request-response model of the old protocol, file changes had to be explicitly asked for. In the new model, however, the client could have a channel with the server (i.e. the container you’re coding in) where file changes are communicated back-and-forth through OT. This made it more efficient versus sending whole files, but, more importantly, it made file changes work concurrently and collaboratively.
Another challenge we had to overcome was moving the file authority from the client to the server. In the past, we made the owner of the repl write file changes from the browser. If we were to do asynchronous collaboration, there would have needed to be some sort of negotiation to figure out which client would be responsible for this in case the owner is not online. But the more sane thing to do was to just move the file authority to the server, which everyone is connected to in the first place.
With the server being the authority on files and file changes, we could now implement a file watching daemon that generates OT messages and broadcasts them to subscribed clients. This has the awesome side-effect of programmatic changes appearing in the editor in real-time complete with its own cursor:
This has been a high-level overview of how we made Repl.it collaborative at heart. In the future, we’ll dive into specific technical and implementation details along with open-sourcing some of the components. For now though, please try it out! Open up a repl, hit that “Invite” button in the header, and starting coding with your friends or coworkers. | https://repl.it/site/blog/collab | CC-MAIN-2019-51 | en | refinedweb |
questions/apache-spark
I am getting error "Exception in thread ...READ MORE
Source tags are different:
{ x : [
{ ...READ MORE
SPARK 1.6, SCALA, MAVEN
i have created a ...READ MORE
import org.apache.spark.SparkContext
import org.apache.spark.SparkConf
import org.apache.spark.SparkContext
import org.apache.spark.SparkConf
import org.apache.spark.sql.hive.HiveContext
import org.apache.spark.sql.functions.{col, ...READ MORE
How can I import zip files and ...READ MORE
Can anyone explain how to define SparkConf? READ MORE
what is the benefit of repartition(1) and ...READ MORE
Can anyone explain what is immutability in ...READ MORE
I'm trying to load data to mysql ...READ MORE
While executing a query I am getting ...READ MORE
When we calculate some use case with ...READ MORE
Can anyone suggest how to create RDD ...READ MORE
I am running an application on Spark ...READ MORE
OR
Already have an account? Sign in. | https://www.edureka.co/community/apache-spark?sort=unanswered | CC-MAIN-2019-51 | en | refinedweb |
public class DocumentUndoManager extends Object implements IDocumentUndoManager
Based on the 3.1 implementation of DefaultUndoManager, it was implemented using the document-related manipulations defined in the original DefaultUndoManager, by separating the document manipulations from the viewer-specific processing.
The classes representing individual text edits (formerly text commands) were promoted from inner types to their own classes in order to support reassignment to a different undo manager.
This class is not intended to be subclassed.
IDocumentUndoManager,
DocumentUndoManagerRegistry,
IDocumentUndoListener,
IDocument
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
public DocumentUndoManager(IDocument document)
document- the document whose undo history is being managed.
public void addDocumentUndoListener(IDocumentUndoListener listener)
Notifications will not be received if there are no clients connected to the receiver. Registering a document undo listener does not implicitly connect the listener to the receiver.
Document undo listeners must be prepared to receive notifications from a background thread. Any UI access occurring inside the implementation must be properly synchronized using the techniques specified by the client's widget library.
addDocumentUndoListenerin interface
IDocumentUndoManager
listener- the document undo listener to be added as a listener
public void removeDocumentUndoListener(IDocumentUndoListener listener)
Removing a listener which is not registered has no effect
removeDocumentUndoListenerin interface
IDocumentUndoManager
listener- the document undo listener to be removed
public IUndoContext getUndoContext()
getUndoContextin interface
IDocumentUndoManager
public void commit()
commitin interface
IDocumentUndoManager
public void reset()
resetin interface
IDocumentUndoManager
public boolean redoable()
redoablein interface
IDocumentUndoManager
trueif at least on text change can be repeated
public boolean undoable()
undoablein interface
IDocumentUndoManager
trueif at least one text change can be rolled back
public void redo() throws ExecutionException
redoin interface
IDocumentUndoManager
ExecutionException- if an exception occurred during redo
public void undo() throws ExecutionException
undoin interface
IDocumentUndoManager
ExecutionException- if an exception occurred during undo
public void connect(Object client)
connectin interface
IDocumentUndoManager
client- the object connecting to the undo manager
public void disconnect(Object client)
disconnectin interface
IDocumentUndoManager
client- the object disconnecting from the undo manager
public void beginCompoundChange()
endCompoundChangeis called are to be undone in one piece.
beginCompoundChangein interface
IDocumentUndoManager
public void endCompoundChange()
beginCompoundChangehas been finished. All subsequent changes are considered to be individually undo-able.
endCompoundChangein interface
IDocumentUndoManager
public void setMaximalUndoLevel(int undoLimit)
setMaximalUndoLevelin interface
IDocumentUndoManager
undoLimit- the length of this undo manager's history
public void transferUndoHistory(IDocumentUndoManager manager)
transferUndoHistoryin interface
IDocumentUndoManager
manager- the document undo manger whose history is to be transferred to the receiver
Copyright (c) 2000, 2015 Eclipse Contributors and others. All rights reserved.Guidelines for using Eclipse APIs. | https://help.eclipse.org/mars/topic/org.eclipse.platform.doc.isv/reference/api/org/eclipse/text/undo/DocumentUndoManager.html | CC-MAIN-2019-51 | en | refinedweb |
IEEE/The Open Group
2013
PROLOG
This manual page is part of the POSIX Programmer’s Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
NAME
syslog.h — definitions for system error logging
SYNOPSIS
#include <syslog.h>
DESCRIPTION
The <syslog.h> header shall define the following symbolic constants, zero or more of which may be OR’ed together to form the logopt option of openlog(): The <syslog.h> header shall define the following symbolic constants for use as the facility argument to openlog(): The <syslog.h> header shall define the following macros for constructing the maskpri argument to setlogmask(). The following macros expand to an expression of type int when the argument pri is an expression of type int: The <syslog.h> header shall define the following symbolic constants for use as the priority argument of syslog(): POSIX.1-2008, close . | https://reposcope.com/man/en/0p/syslog.h | CC-MAIN-2019-51 | en | refinedweb |
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