id int64 5 1.93M | title stringlengths 0 128 | description stringlengths 0 25.5k | collection_id int64 0 28.1k | published_timestamp timestamp[s] | canonical_url stringlengths 14 581 | tag_list stringlengths 0 120 | body_markdown stringlengths 0 716k | user_username stringlengths 2 30 |
|---|---|---|---|---|---|---|---|---|
1,897,233 | Tensorman: TensorFlow with CUDA made easy | Getting TensorFlow to work with CUDA can be a real headache. You have to make sure that the versions... | 0 | 2024-06-22T17:26:18 | https://dev.to/tallesl/tensorman-tensorflow-with-cuda-made-easy-48km | tensorflow, cuda, nvidia | Getting TensorFlow to work with CUDA can be a real headache. You have to make sure that the versions of TensorFlow, CUDA, cuDNN match up. Missing one small detail can throw everything off.
Luckly, Google provides some [pre-configured Docker images](https://hub.docker.com/r/tensorflow/tensorflow) so you don't have to deal with this hassle. But there is still a bit of a hassle in managing the container, right?
Making things even easier, the lovely folks from System76 created [Tensorman](https://github.com/pop-os/tensorman), which abstracts away all the complexity of pulling the container, running our app, stopping, removing the container, etc.
## Running TensorFlow with Tensorman
With Tensorman installed (`apt install tensorman` from PopOS), it's as easy as:
```
$ tensorman run --gpu python -- ./script.py
```
This takes care of everything, even stopping and removing the container once the process goes down.
## Testing
Here's a sample script if you want to test it out:
```
import tensorflow as tf
print("TensorFlow version:", tf.__version__)
print("CUDA support:", tf.test.is_built_with_cuda())
print("GPU available:", tf.config.list_physical_devices('GPU'))
matrix1 = tf.constant([[1., 2., 3.], [4., 5., 6.], [7., 8., 9.]])
matrix2 = tf.constant([[1., 2., 3.], [4., 5., 6.], [7., 8., 9.]])
product = tf.matmul(matrix1, matrix2)
print("Matrix multiplication result: ", product.numpy())
```
## Removing NUMA warning messages
When running my sample script I got my output as expected:
Ugh, I don't want all those NUMA warning messages on my output. Here's how I've disable it (thanks to this [gist](https://gist.github.com/zrruziev/b93e1292bf2ee39284f834ec7397ee9f)):
```
$ lspci | grep -i nvidia
10:00.0 VGA compatible controller: NVIDIA Corporation TU104 [GeForce RTX 2060] (rev a1)
10:00.1 Audio device: NVIDIA Corporation TU104 HD Audio Controller (rev a1)
10:00.2 USB controller: NVIDIA Corporation TU104 USB 3.1 Host Controller (rev a1)
10:00.3 Serial bus controller: NVIDIA Corporation TU104 USB Type-C UCSI Controller (rev a1)
$ sudo echo 0 | sudo tee -a "/sys/bus/pci/devices/0000:10:00.0/numa_node"
0
```
Running again:
Still noisy, but much better.
| tallesl |
1,897,232 | Computer Science Challenge: Recursion | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-22T17:24:40 | https://dev.to/darshanraval/computer-science-challenge-recursion-2c8h | devchallenge, cschallenge, computerscience, beginners | *This is a submission for [DEV Computer Science Challenge v24.06.12: One Byte Explainer](https://dev.to/challenges/cs).*
## Explainer
Recursion: Recursion is a programming method that involves a function calling itself to address versions of an issue until it reaches a base scenario. This technique plays a role, in activities such as navigating trees and organizing data making the code more straightforward and less complicated, by dividing challenges into easier-to-handle components.
## Additional Context
<!-- Please share any additional context you think the judges should take into consideration as it relates to your One Byte Explainer. -->
Recursion, in programming, involves a technique where a function calls itself to address instances of a problem. This method continues until it reaches a base case, which is a condition where the problem becomes simple enough to be solved stopping further recursive calls. The use of recursion is crucial in tasks such as navigating trees, where each node's subtrees are processed sequentially, and in sorting algorithms like quicksort and mergesort which divide arrays into segments for sorting. Through recursion complex problems are broken down into parts resulting in code that is often simpler and easier to understand. It is important to use recursion to prevent issues like loops and stack overflow errors, which can arise when the base case is not reached or the recursion depth becomes too high. Having a grasp of recursion aids, in developing elegant solutions for various computational challenges.
<!-- Team Submissions: Please pick one member to publish the submission and credit teammates by listing their DEV usernames directly in the body of the post. -->
<!-- Don't forget to add a cover image to your post (if you want). -->
<!-- Thanks for participating! --> | darshanraval |
1,897,230 | 🚀 Exciting Update: SimpliLearn Certifications Achieved! 🎓 | Hello Everyone, Certifications Link : SimpliLearn-Certifications I'm excited to announce that I've... | 0 | 2024-06-22T17:22:09 | https://dev.to/bvidhey/exciting-update-simplilearn-certifications-achieved-245o | Hello Everyone,
**Certifications Link :** [SimpliLearn-Certifications](https://github.com/Vidhey012/My-Certifications/tree/main/SimpliLearn)
I'm excited to announce that I've successfully completed certifications with SimpliLearn! These certifications have been instrumental in enhancing my skills and expertise in [mention the field or specialization]. I've gained valuable insights and hands-on experience that I'm eager to apply in my professional endeavors.
I extend my gratitude to everyone who has supported me throughout this journey. Your encouragement has been invaluable.
Here's to continuous learning and leveraging these certifications to unlock new opportunities in my career! | bvidhey | |
1,897,181 | Documenting my pin collection with Segment Anything: Part 4 | Welcome to the fourth entry in my series where I document my journey of cataloguing my enamel pin... | 27,656 | 2024-06-22T17:21:30 | https://blog.feregri.no/blog/documenting-my-pin-collection-with-segment-anything-part-4/ | jquery, javascript, html, python | Welcome to the fourth entry in my series where I document my journey of cataloguing my enamel pin collection. If you missed the previous posts, you can catch up [**here**](https://dev.to/feregri_no/series/27656). Previously, [I introduced a simple app](https://dev.to/feregri_no/documenting-my-pin-collection-with-segment-anything-part-3-4iam) that segments each pin, assigning unique identifiers and names. Although I shared some future enhancements at the end of my last post, it dawned on me that I had slightly deviated from my main objective: **effectively showcase my collection**.
In this update, I'll take you through the process of integrating all previous developments into a single interactive webpage. This page highlights each pin, with detailed information accessible via mouse hover, all crafted using HTML, JavaScript, and jQuery.
As always, let me show you what the end product looks like:
{% youtube 2uNkWPo6XAI %}
And the live web page of my [pin collection showcase v2 here](https://pins.feregri.no/v2/).
## Improving the quality of the cutout
Before getting into the front-end development, I wanted to try a couple of things to improve the quality of the cutout.
If you remember, from a previous post, the output of the Segment Anything Model is a set of masks covering where the segmented object is, however, for my use case the edges of the masks always ended up being a bit jagged, too pointy and complex, so I created the following function in an attempt to simplify the edges of the mask:
```python
def refine_mask(image, mask):
polygons = [Polygon(poly) for poly in sv.mask_to_polygons(mask)]
single_polygon = unary_union(polygons)
if single_polygon.geom_type == "Polygon":
selected_polygon = single_polygon
elif single_polygon.geom_type == "MultiPolygon":
selected_polygon = max(single_polygon.geoms, key=lambda x: x.area)
else:
raise ValueError(f"Unexpected geometry type: {single_polygon.geom_type}")
simplified_polygon = simplify(selected_polygon, 1.0)
selected_polygon = simplified_polygon.buffer(10, join_style=1).buffer(-10.0, join_style=1)
polygon = []
for x, y in zip(selected_polygon.exterior.xy[0], selected_polygon.exterior.xy[1]):
polygon.append(x)
polygon.append(y)
new_mask = sv.polygon_to_mask(
np.array(selected_polygon.exterior.coords, dtype=np.int32),
(image.shape[1], image.shape[0]),
)
return new_mask, polygon
```
A brief description of the function behaviour is:
### Parameters
- **image**: This is the original image associated with the mask. It is used to determine the dimensions for the new mask.
- **mask**: This is a binary mask produced by SAM where the areas of interest are marked.
### Function Body
#### Convert Mask to Polygons
```python
polygons = [Polygon(poly) for poly in sv.mask_to_polygons(mask)]
```
Converts the mask into a list of `shapely`’s `Polygon` objects. It is achieved by detecting contours or similar features in the mask using the `supervision` library’s `mask_to_polygons`.
#### Merge Polygons
```python
single_polygon = unary_union(polygons)
```
Combines these polygons into a single polygon using `shapely.ops.unary_union`, which efficiently merges overlapping or adjacent polygons.
#### Select Largest Polygon (if necessary)
```python
if single_polygon.geom_type == "Polygon":
selected_polygon = single_polygon
elif single_polygon.geom_type == "MultiPolygon":
selected_polygon = max(single_polygon.geoms, key=lambda x: x.area)
else:
raise ValueError(f"Unexpected geometry type: {single_polygon.geom_type}")
```
Checks the geometry type of the resultant polygon. If it's a `MultiPolygon` (which in my case happens quite often), it selects the polygon with the largest area, assuming that that largest area is one that contains the pin.
#### Simplify Polygon
```python
simplified_polygon = simplify(selected_polygon, 1.0)
```
Simplifies the polygon's shape to reduce the number of vertices, making the shape easier to handle and process, the `simplify` function comes from the `shapely` module.
#### Buffering
```python
selected_polygon = simplified_polygon.buffer(10, join_style=1).buffer(-10.0, join_style=1)
```
Applies a buffer of 10 units outward and then -10 units inward to smooth and regularise the edges, potentially cleaning up the polygon's boundary.
#### Extract Coordinates
```python
polygon = []
for x, y in zip(selected_polygon.exterior.xy[0], selected.polygons.exterior.xy[1]):
polygon.append(x)
polygon.append(y)
```
Extracts the x and y coordinates from the exterior of the selected polygon and stores them in a list where the coordinates are laid like this: `[x1, y1, x2, y2, ..., xn, yn]`, which is useful when showing the polygon in the front end as image maps.
#### Convert Polygon to Mask
```python
new_mask = sv.polygon_to_mask(
np.array(selected_polygon.exterior.coords, dtype=np.int32),
(image.shape[1], image.shape[0]),
)
```
Finally, converts the simplified polygon back into a mask format with the original image's dimensions.
### Returns
- **new_mask**: The refined mask derived from the largest or simplified polygon.
- **polygon**: The coordinates of the simplified polygon.
### Some results
In this image, it is possible to see how in the original cutout there was an extra bit of image that does not belong to the pin badge, with the refining function we got rid of it.
The refining function not only helps in removing the unwanted bits of the image but also helps in removing empty spaces that should not be there.
However, the benefits of the refining function is not always visible, as shown above.
## Front-end
Now, on to the front-end, where most of the time was invested.
### A new `view` endpoint
I added a new endpoint to my FastAPI app, this endpoint serves the existing masks rendered into an HTML that will show the original image along with an [HTML `map` element](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/map):
```python
@app.get("/view/")
def get_view(request: Request):
existing_cutouts = load_selected_cutouts()
return templates.TemplateResponse(
"view.html.jinja",
{
"request": request,
"imageWidth": og_image.width,
"imageHeight": og_image.height,
"existing_cutouts": existing_cutouts,
"image": turns_image_to_base64(og_image),
},
)
```
### The `view.html.jinja` template:
The template is quite simple since most of the interactivity and functionality is in the JavaScript code that I will explain later:
```html
<!DOCTYPE html>
<html lang="en">
<head>
<!-- Code omitted for brevity -->
</head>
<body>
<img src="{{image}}" alt="Enamel Pins Collection" id="canvasMapContainer" usemap="#pinmap">
<map name="pinmap" id="pinmap">
{%- for cutout in existing_cutouts %}
<area shape="poly" coords="{{cutout.polygon | join(',')}}"
data-name="{{cutout.name}}"
{%- if cutout.description %}
data-description="{{cutout.description}}"
{%- endif %}
alt="{{cutout.name}}" data-key="{{cutout.uuid}}" href="#">
{%- endfor %}
</map>
<!-- Modal -->
<dialog id="modal">
<article>
<header>
<h3 id="infoPinNameModal"></h3>
</header>
<p id="infoPinDescriptionModal"></p>
</article>
</dialog>
<!-- Tooltip -->
<div id="tooltip" style="display: none;">
<article>
<header><h3 id="infoPinNameTooltip"></h3></header>
<p id="infoPinDescriptionTooltip" style="display: none;"></p>
</article>
</div>
<script>
/* Functionality described below */
</script>
</body>
</html>
```
There are five key pieces to this app:
- The `img` tag with `canvasMapContainer` as id. This image will show the image containing all the pins. This image is the same I have been working with across these series of posts. The tag has `src="{{image}}"` where the image is provided via the server as a base46 image. Another thing to note about this image tag is that it has the property `usemap` set to `"#pinmap"`, this lets the browser know that there is an image map attached to this image.
- The `map` tag contains areas that correspond to different parts of the enamel pin canvas, notice how the map’s `name` property matches the value set as `usemap` in the image above. These values are set dynamically at render time, the loop `{%- for cutout in existing_cutouts %}` allows us to create an `area` element with information such as polygon coordinates, name and descriptions for each of the pins.
- A `dialog` tag with `modal` as id. This element is used to display more detailed information about a selected pin. This element is hidden by default and only shown whenever a user clicks on a pin.
- A `div` that works as a floating tooltip that displays basic information about the pin over which the user is hovering the cursor. Just like the modal dialog above, this tooltip is hidden initially and shown on certain interactions defined in the script below.
- The fifth element is a `script` that orchestrates the whole functionality of the app, it requires more than a simple paragraph to explain its functionality, continue reading to learn more about it.
### The app’s logic
**Dependencies**
1. **jQuery**: A fast, small, and feature-rich JavaScript library, some people may think it is quite outdated, however, it simplifies things like HTML document traversal and manipulation, event handling, and even animation.
2. **ImageMapster**: A jQuery plugin that provides interactive image maps functionality. It allows images to be used with areas that can be manipulated and interacted with in various ways.
**Functionality**
Everything happens after the document has been loaded, inside a `$(document).ready(function() { });` definition.
**Modal and Tooltip Interaction**:
The script initialises variables for modal and tooltip elements, as well as several configuration variables for classes and animation timing.
```jsx
const $modal = $("#modal");
const isOpenClass = "modal-is-open";
const openingClass = "modal-is-opening";
const closingClass = "modal-is-closing";
const scrollbarWidthCssVar = "--pico-scrollbar-width";
const animationDuration = 400; // ms
const padding = 10;
const $tooltip = $("#tooltip");
const $infoPinNameTooltip = $("#infoPinNameTooltip");
const $infoPinNameModal = $("#infoPinNameModal");
const $canvasMapContainer = $("#canvasMapContainer");
let visibleModal = null;
```
It defines functions to toggle, open, and close the modal. The modal can be opened or closed either by clicking on an area of the image map or using the Escape key.
```jsx
// Toggle modal
const toggleModal = () => {
if (!$modal.length) return;
$modal[0].open ? closeModal() : openModal();
};
// Open modal
const openModal = () => {
$("html").addClass(isOpenClass).addClass(openingClass);
setTimeout(() => {
visibleModal = $modal;
$("html").removeClass(openingClass);
}, animationDuration);
$modal[0].showModal();
};
// Close modal
const closeModal = () => {
visibleModal = null;
$("html").addClass(closingClass);
setTimeout(() => {
$("html").removeClass(closingClass).removeClass(isOpenClass);
$("html").css(scrollbarWidthCssVar, '');
$modal[0].close();
}, animationDuration);
};
// Close with a click outside
$(document).on("click", (event) => {
if (visibleModal === null) return;
const isClickInside = $(visibleModal).find("article").has(event.target).length > 0;
if (!isClickInside) closeModal();
});
// Close with Esc key
$(document).on("keydown", (event) => {
if (event.key === "Escape" && visibleModal) {
closeModal();
}
});
```
**Interactive Image Map Setup**
The image map is initialized with the ImageMapster plugin, which is configured to not allow selection (highlighting) of map areas but to react to mouse events – [this plugin’s documentation](https://jamietre.github.io/ImageMapster/reference/configuration-reference/) is top-notch.
```jsx
$canvasMapContainer.mapster({
enableAutoResizeSupport: true,
autoResize: true,
isSelectable: false,
stroke: false,
strokeColor: '00FF00',
strokeWidth: 5,
mapKey: 'data-key',
fillOpacity: 0.0,
// ....
```
On clicking an image map area, the script fetches the area's data attributes (like name), updates the modal's content, and toggles the modal's visibility.
```jsx
onClick: function (data) {
$infoPinNameModal.text(data.e.target.dataset.name);
toggleModal();
}
```
On mouseover, the tooltip's content is updated based on the hovered area's data attributes, and its position is dynamically calculated to appear near the cursor but adjusted to avoid overflowing the viewport.
```jsx
onMouseout: function() {
$tooltip.hide();
},
onMouseover: function(data) {
// ... see below for the dynamic positioning
```
**Dynamic Positioning**:
The tooltip's position is calculated based on the coordinates of the hovered area. The script ensures that the tooltip does not overflow the window edges by adjusting its position relative to the image map area's boundaries.
Position calculations take into account the current scroll position and the tooltip's dimensions to ensure it is always visible.
```jsx
const coords = $(this).attr('coords').split(',').map(coord => parseInt(coord, 10));
const xCoords = coords.filter((_, i) => i % 2 === 0);
const yCoords = coords.filter((_, i) => i % 2 === 1);
const x1 = Math.min(...xCoords);
const y1 = Math.min(...yCoords);
const x2 = Math.max(...xCoords);
const y2 = Math.max(...yCoords);
const centerX = (x1 + x2) / 2;
$infoPinNameTooltip.text(data.e.target.dataset.name);
const infoWidth = $tooltip.width();
const infoHeight = $tooltip.height();
let positionX = "centre";
if (x1 - infoWidth - padding < 0) {
positionX = "left";
} else if (x2 + infoWidth + padding > $canvasMapContainer.width()) {
positionX = "right";
}
let positionY = "top";
if (y1 - infoHeight - padding < $(window).scrollTop()) {
positionY = "bottom";
}
const positionXmap = {
"left": x2 + padding,
"centre": centerX - infoWidth / 2,
"right": x1 - infoWidth - padding
};
const positionYmap = {
"top": y1 - padding - infoHeight,
"bottom": y2 + padding
};
$tooltip.css({
top: positionYmap[positionY],
left: positionXmap[positionX],
}).show();
```
In a real-world production app, this script probably should exist in its own file, however, as this is just a toy project, it is currently inlined along with the HTML code.
## Conclusion
This project has been an enriching learning experience, and although the results haven't fully met my expectations yet, I believe it's time for a pause. Juggling multiple interests and responsibilities, including learning, writing, and teaching, demands that I prioritise my commitments.
In the meantime, I will keep a list of the ideas that come to my mind to improve the results of the processes I have been describing here, and, if you have ideas on how I could improve this project or want to share your experiences with similar projects, please leave a comment below or reach out to me on [Twitter](hhttps://twitter.com/feregri_no).
If you are looking for all the code I have written so far, [everything is on GitHub](https://github.com/fferegrino/pin-detection-with-sam), feel free to use it for your own projects!
| feregri_no |
1,897,228 | A Beginner's Guide to Game Development | Whether you're a coding enthusiast or a creative soul with a passion for storytelling, this post is... | 0 | 2024-06-22T17:21:22 | https://dev.to/gauravk_/a-beginners-guide-to-game-development-2mm0 | gamedev, coding, softwaredevelopment | Whether you're a coding enthusiast or a creative soul with a passion for storytelling, this post is here to guide you through the process of learning game development from scratch.
> A game is the complete exploration of freedom within a restrictive environment.
**_Set Your Goals_**
Before you start learning game development, it's crucial to define your goals. Set a clear set of goals in front of you before starting the development of games. Its involves
- What kind of game do you have in mind?
- Do you want to make 2D games or 3D games?
- Which type of games do you wish to design; for mobile, console, or perhaps for the PC?
By having a clear vision of what you want to achieve, you can work on your learning process and on the specific skills and tools needed for your chosen path.
**_Choose Your Game Engine_**
Game engines are the backbone of game development. They help facilitate and define how your creative visions will be implemented. Some of the best game engine out there are [Unity3D](https://unity.com/), [Unreal](https://www.unrealengine.com/en-US), and [Godot](https://godotengine.org/). All of which comes set of features, extensive documentation, and a vibrant community. Spent more time to test the various engines available so as to determine the most appropriate one depending on the on the persons style and the intended plan. You can skip this step for small game projects.
**_Explore Game Art_**
To bring your game worlds to life, learning concepts like concepts of Sprite, 3D modeling & sculpting, animation, texturing and Shader system is a valuable skill set. Dive into the world of software like [Blender](https://www.blender.org/), or [Maya](https://www.autodesk.com/in) and start creating your own 3D assets. Learn the basics of modeling, texturing, and rigging. Additionally, mastering animation techniques will allow you to give movement and personality to your creations, making your games even more immersive and visually stunning.
**_Learn the Basics of Programming_**
I can agree with the fact that game engines facilitate the game development but it’s always better to know programming basics. Familiarize yourself with programming languages such as C# (for Unity), C++ (for Unreal Engine), or Python (for Godot). You can even try Block Coding. Besides, there are numerous video tutorials, articles, and online courses you are try if you’re starting your journey. Always practice coding everyday at least for some time to maintain a strong knowledge of what you are doing and to build your confidence.
**_Start Small and Prototype_**
Game development can be overwhelming, especially for beginners. To avoid getting lost in the complexity, start with small projects and prototypes. Simple games like Pong or Breakout are excellent starting points. Prototyping allows you to experiment, learn, and iterate quickly, giving you a taste of the game development process without feeling overwhelmed.
**_Embrace the Art of Game Design_**
Game development is more than writing programs and compiling a series of coding languages, it is about interesting games. Dive into the world of game design, where you can unleash your creativity and make games that truly engage players.
**_Join the Community_**
The game development community is a treasure of knowledge, support, and inspiration. Engage with fellow game developers through forums, social media, and local meetups. Participate in game jams, where you'll collaborate with others to create games within a limited timeframe. Sharing your work (best when shared with me), receiving feedback, and learning from experienced developers will accelerate your growth and keep you motivated.
**_Never Stop Learning_**
Game development is a continuously evolving field. New technologies, techniques, and trends emerge regularly. Stay updated by following industry blogs (Like this blog), attending conferences, and experimenting with new tools and frameworks. Remember, learning is a lifelong journey, and every step you take will bring you closer to becoming a game development wizard.
> The successful free to play games are selling positive emotions, Not content.
-Nicholas Lovell | gauravk_ |
1,897,180 | PageRequest | PageRequest, Spring Data JPA'nın veri kümesini sayfalara bölmek ve sıralamak için kullandığı bir... | 0 | 2024-06-22T17:19:56 | https://dev.to/mustafacam/pagerequest-52ob | `PageRequest`, Spring Data JPA'nın veri kümesini sayfalara bölmek ve sıralamak için kullandığı bir sınıftır. Sayfalama, büyük veri kümeleriyle çalışırken performansı artırmak ve kullanıcılara daha iyi bir deneyim sunmak için önemli bir tekniktir. Sayfalama, tüm veri kümesini tek seferde yüklemek yerine, verileri belirli büyüklükteki parçalara (sayfalara) bölerek yükler.
### PageRequest ve Sayfalamanın Faydaları
1. **Performans İyileştirmesi**:
- Büyük veri kümeleriyle çalışırken, tüm verileri tek seferde yüklemek veritabanı ve uygulama performansını olumsuz etkileyebilir. Sayfalama, sadece ihtiyaç duyulan verileri yükleyerek bu sorunu azaltır.
2. **Bellek Kullanımı**:
- Tüm veri kümesini bellek üzerinde tutmak yerine, sadece istenen sayfayı bellek üzerinde tutarak bellek kullanımını optimize eder.
3. **Kullanıcı Deneyimi**:
- Kullanıcılara daha hızlı yanıt süreleri sunar. Kullanıcılar genellikle tüm veri kümesini görmek istemezler; bunun yerine verileri sayfalar halinde görmek daha kullanışlıdır.
4. **Sıralama**:
- Verileri belirli bir alana göre sıralama imkanı sunar. Örneğin, ürünleri fiyatlarına göre artan veya azalan sırada gösterebilirsiniz.
### `PageRequest` Kullanımı
Kod örneğimizde `PageRequest`'in nasıl kullanıldığını inceleyelim:
```java
public Set<ProductResponse> getAll(ProductSearchRequest request) {
Specification<Product> productSpecification = ProductSpecification.initProductSpecification(request);
// Sayfalama ve sıralama için PageRequest oluşturulması
PageRequest pageRequest = PageRequest.of(request.getPage(), request.getSize(), Sort.by(Sort.Direction.ASC, "amount"));
// Sayfalama ve spesifikasyon ile ürünlerin getirilmesi
Page<Product> products = productRepository.findAll(productSpecification, pageRequest);
log.info("db'den getirildi. product size:{}", products.getSize());
return ProductConverter.toResponse(products.stream().toList());
}
```
### Açıklama
1. **PageRequest Oluşturulması**:
```java
PageRequest pageRequest = PageRequest.of(request.getPage(), request.getSize(), Sort.by(Sort.Direction.ASC, "amount"));
```
- `PageRequest.of(int page, int size, Sort sort)` metodu, belirli bir sayfa numarası (`page`), sayfa başına kayıt sayısı (`size`) ve sıralama kriteri (`sort`) ile bir `PageRequest` nesnesi oluşturur.
- `request.getPage()`: Hangi sayfanın yükleneceğini belirtir (0 tabanlı indeks).
- `request.getSize()`: Sayfa başına kaç kaydın yükleneceğini belirtir.
- `Sort.by(Sort.Direction.ASC, "amount")`: Kayıtların `amount` alanına göre artan sırada sıralanacağını belirtir. Bu, ürünleri fiyatlarına göre artan sırada sıralar.
2. **Veritabanı Sorgusu**:
```java
Page<Product> products = productRepository.findAll(productSpecification, pageRequest);
```
- `productRepository.findAll(Specification spec, Pageable pageable)` metodu, belirli bir spesifikasyona ve sayfalama kriterlerine göre veritabanından kayıtları getirir.
- Bu örnekte, `productSpecification` ve `pageRequest` kullanılarak, belirli bir sayfaya ait ürünler `amount` alanına göre sıralanmış olarak getirilir.
3. **Sonuçların Dönüşümü**:
```java
return ProductConverter.toResponse(products.stream().toList());
```
- Veritabanından getirilen `Product` nesneleri `ProductResponse` nesnelerine dönüştürülür ve set olarak döner.
### Özet
`PageRequest`, Spring Data JPA'nın veri kümesini sayfalara bölmek ve sıralamak için kullandığı bir sınıftır. Bu, büyük veri kümeleriyle çalışırken performansı artırmak, bellek kullanımını optimize etmek ve kullanıcılara daha iyi bir deneyim sunmak için önemli bir tekniktir. `PageRequest` kullanarak, sadece belirli bir sayfadaki kayıtları yükleyebilir ve verileri belirli bir alana göre sıralayabilirsiniz. | mustafacam | |
1,897,179 | 🎓 Exciting News: GreatLearning Certifications Achieved! 🚀 | Hello Everyone, Certification Link : GreatLearning-Certifications I am thrilled to share that I... | 0 | 2024-06-22T17:19:44 | https://dev.to/bvidhey/exciting-news-greatlearning-certifications-achieved-1h63 | Hello Everyone,
**Certification Link :** [GreatLearning-Certifications](https://github.com/Vidhey012/My-Certifications/tree/main/GreatLearning)
I am thrilled to share that I have successfully completed certification programs with GreatLearning! These certifications signify my commitment to enhancing my skills and knowledge in Computer Sciences. The courses have equipped me with valuable insights and practical skills that I'm eager to apply in my professional journey.
Thank you to everyone who has supported me along the way. Your encouragement means a lot.
Here's to continuous growth and leveraging these certifications to achieve new milestones in my career! | bvidhey | |
1,897,177 | 🎓 Exciting News: Cisco Certifications Achieved! 🌟 | Dear Friends and Colleagues, Certifications Link : Cisco-Certifications I'm thrilled to announce a... | 0 | 2024-06-22T17:15:26 | https://dev.to/bvidhey/exciting-news-cisco-certifications-achieved-5e67 | Dear Friends and Colleagues,
**Certifications Link :** [Cisco-Certifications](https://github.com/Vidhey012/My-Certifications/tree/main/Cisco)
I'm thrilled to announce a significant milestone in my career journey – I have successfully earned Cisco certifications! 🚀 These certifications represent my commitment to advancing my knowledge and expertise in networking and cybersecurity, two crucial pillars in today's digital landscape.
Cisco's rigorous training programs have equipped me with industry-leading skills, empowering me to tackle complex networking challenges and enhance cybersecurity measures. This achievement wouldn't have been possible without the support of mentors, colleagues, and my relentless pursuit of knowledge.
I'm excited to apply these newfound skills to drive innovation, efficiency, and security in our digital environments. Thank you to Cisco for their exceptional training programs and to everyone who supported me along this journey.
Here's to continuous learning, growth, and embracing new opportunities in the ever-evolving world of technology! | bvidhey | |
1,897,176 | 🎓 Proud Moment: EduSkills Code Riders 2021 Certificate Achievement! 🚀 | Dear Friends, I'm thrilled to share a significant achievement with you all – I've successfully... | 0 | 2024-06-22T17:13:47 | https://dev.to/bvidhey/proud-moment-eduskills-code-riders-2021-certificate-achievement-1plh | Dear Friends,
I'm thrilled to share a significant achievement with you all – I've successfully completed the EduSkills Code Riders 2021 program! 🌟 This journey has been an incredible opportunity to delve deeper into the world of coding, sharpen my skills, and collaborate with passionate individuals from diverse backgrounds.
Throughout the program, we explored various facets of programming, tackled challenging projects, and learned from industry experts. It's been a rewarding experience that has enriched my knowledge and passion for technology.
A heartfelt thanks to the EduSkills team for organizing this enriching initiative and to my peers for their constant support and collaboration. I'm excited to leverage the skills gained here to contribute meaningfully to future projects and continue my journey of growth in the tech world.
Here's to continuous learning, exploration, and the pursuit of excellence! 🎓🚀 | bvidhey | |
1,897,108 | JpaRepository ve JpaSpecificationExecutor | JpaRepository JpaRepository, Spring Data JPA tarafından sağlanan ve JPA (Java Persistence... | 0 | 2024-06-22T14:56:48 | https://dev.to/mustafacam/jparepository-ve-jpaspecificationexecutor-3nch | ### JpaRepository
`JpaRepository`, Spring Data JPA tarafından sağlanan ve JPA (Java Persistence API) tabanlı veri erişim katmanını kolaylaştırmak için kullanılan bir arayüzdür. `JpaRepository` arayüzü, CRUD (Create, Read, Update, Delete) işlemlerini gerçekleştirmek için çeşitli metodlar sağlar. Bu arayüz, `PagingAndSortingRepository` arayüzünü genişletir, bu nedenle veri kümesini sayfalandırma ve sıralama desteği de sunar.
#### Sağladığı Metodlar
`JpaRepository` arayüzü, veritabanı işlemleri için bir dizi hazır metod içerir:
- **save(S entity)**: Verilen varlığı kaydeder veya günceller.
- **findById(ID id)**: Verilen kimlik değeri ile varlığı bulur.
- **findAll()**: Tüm varlıkları döner.
- **findAll(Pageable pageable)**: Tüm varlıkları sayfalandırılmış biçimde döner.
- **deleteById(ID id)**: Verilen kimlik değeri ile varlığı siler.
- **count()**: Varlıkların toplam sayısını döner.
- **existsById(ID id)**: Verilen kimlik değeri ile bir varlığın olup olmadığını kontrol eder.
#### Kullanım
`JpaRepository` arayüzünü kullanarak, veritabanı işlemleri için gerekli temel metodları kolayca ekleyebilirsiniz. İşte bir örnek:
```java
package com.example.demo.repository;
import com.example.demo.model.Product;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
@Repository
public interface ProductRepository extends JpaRepository<Product, Long> {
// Ekstra sorgular buraya eklenebilir
}
```
### JpaSpecificationExecutor
`JpaSpecificationExecutor`, Spring Data JPA tarafından sağlanan ve JPA kriter tabanlı sorgularını gerçekleştirmek için kullanılan bir arayüzdür. Bu arayüz, dinamik ve esnek sorgular oluşturmayı sağlar.
#### Sağladığı Metodlar
`JpaSpecificationExecutor` arayüzü, kriter tabanlı sorgular için çeşitli metodlar içerir:
- **findAll(Specification<T> spec)**: Verilen spesifikasyona uygun tüm varlıkları bulur.
- **findAll(Specification<T> spec, Pageable pageable)**: Verilen spesifikasyona uygun tüm varlıkları sayfalandırılmış biçimde bulur.
- **count(Specification<T> spec)**: Verilen spesifikasyona uygun varlıkların sayısını döner.
- **exists(Specification<T> spec)**: Verilen spesifikasyona uygun varlıkların olup olmadığını kontrol eder.
#### Kullanım
`JpaSpecificationExecutor` arayüzü, dinamik sorgular oluşturmak için kullanılır. Bu sorgular, `Specification` arayüzü kullanılarak tanımlanır. İşte bir örnek:
```java
package com.example.demo.repository;
import com.example.demo.model.Product;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import org.springframework.stereotype.Repository;
@Repository
public interface ProductRepository extends JpaRepository<Product, Long>, JpaSpecificationExecutor<Product> {
// Ekstra sorgular ve spesifikasyonlar buraya eklenebilir
}
```
### Specification Kullanımı
`Specification` arayüzü, kriter tabanlı sorgular oluşturmak için kullanılır. İşte bir örnek:
```java
package com.example.demo.specification;
import com.example.demo.model.Product;
import org.springframework.data.jpa.domain.Specification;
public class ProductSpecification {
public static Specification<Product> hasName(String name) {
return (root, query, criteriaBuilder) ->
criteriaBuilder.equal(root.get("name"), name);
}
public static Specification<Product> hasPrice(BigDecimal price) {
return (root, query, criteriaBuilder) ->
criteriaBuilder.equal(root.get("price"), price);
}
}
```
Bu spesifikasyonlar daha sonra repository metodlarında kullanılabilir:
```java
import com.example.demo.model.Product;
import com.example.demo.repository.ProductRepository;
import com.example.demo.specification.ProductSpecification;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.math.BigDecimal;
import java.util.List;
@Service
public class ProductService {
@Autowired
private ProductRepository productRepository;
public List<Product> findProductsByNameAndPrice(String name, BigDecimal price) {
return productRepository.findAll(
Specification.where(ProductSpecification.hasName(name))
.and(ProductSpecification.hasPrice(price))
);
}
}
```
Bu şekilde, `JpaRepository` ve `JpaSpecificationExecutor` arayüzleri ile CRUD işlemleri ve dinamik sorgular için güçlü ve esnek bir veri erişim katmanı oluşturabilirsiniz. | mustafacam | |
1,897,175 | JavaScript Main Concepts < In Depth > Part 2 | click for Part 1 6. Closures A closure is the combination of a function bundled together... | 0 | 2024-06-22T17:13:22 | https://dev.to/rajatoberoi/javascript-main-concepts-in-depth-part-2-2mfn | beginners, tutorial, node, codenewbie | [click for Part 1](https://dev.to/rajatoberoi/javascript-main-concepts-edg)
## 6. Closures
A closure is the combination of a function bundled together (enclosed) with references to its surrounding state (the lexical environment).
- A closure gives you access to an outer function's scope from an inner function.
```
let b = 3;
function impureFunc(a) {
return a + b;
}
```
In order to call a function in our code, JS interpreter needs to know about the function it self and any other data from the surroundings environment that it depends on.
Everything needs to be neatly closed up into a box before it can be fed into the machine.
A pure function is a function where the output is determined solely by its input values, without observable side effects. Given the same inputs, a pure function will always return the same output.
```
//Stored in call stack
function pureFunc(a, b) {
return a + b;
}
```
Stack Memory:
A: 2
B: 3
Call Stack:
pureFunc(2, 3)
An impure function is a function that interacts with or modifies some state outside its own scope, which means its output can vary even with the same inputs.
- In below example, in order to interpreter to call this function and also know the value of this free variable, it creates a closure and store them in a place in memory from where they can be access later. That area of memory is called the Heap.
- Call stack memory is short lived, and heap memory can keep data indefinitely. Later memory gets freed using GC.
- So a closure is a combination of a function with it's outer state or lexical environment.
- Closure requires more memory than pure functions.
```
let b = 3;//free variable
function impureFunc(a) {
return a + b;
}
```
- Impure functions often rely on external state. Closures can encapsulate and manage this state within a function scope, making it possible to create stateful functions without resorting to global variables.
```
function createCounter() {
let count = 0; // This is the external state
return function() {
count += 1; // Impure function: modifies the external state
return count;
};
}
const counter = createCounter();
console.log(counter()); // 1
console.log(counter()); // 2
console.log(counter()); // 3
```
- The count variable is encapsulated in the closure created by createCounter.
- This allows the count variable to persist between function calls, while keeping it private and preventing it from being modified directly from the outside.
So,
- Closures are often used in JavaScript to create functions with "private" variables or to maintain state across multiple function calls.
Memory Management and Closures:
- In JavaScript, closures involve storing function references along with their surrounding state. This state is stored in memory, typically in the heap, as it needs to persist beyond the scope of the function execution.
- When a function with a closure is no longer referenced, the memory it occupies can be garbage collected (GC). However, as long as there are references to the closure, the variables in its scope will not be freed.
Use Case of closure: Memoization
The Fibonacci sequence is a classic example where memoization can significantly improve performance. The naive recursive approach has exponential time complexity due to repeated calculations of the same values.
Naive Recursive Fibonacci Function(inefficient):
```
function findFabonacciRecursive(number) {
if (number < 2) {
return number;
}
return findFabonacciRecursive(number - 1) + findFabonacciRecursive(number - 2);
}
console.log(findFabonacciRecursive(10)); // 55
```
In this approach, the same values of fibonacci(n) are recalculated multiple times, leading to inefficiency. By memoizing the results of the function calls, we can avoid redundant calculations and improve the performance.
Memoized Fibonacci Function:
```
// Memoized Fibonacci function using a closure
function fibonacciMaster() {
let cache = {};
return function fib(n) {
if (n in cache) {
return cache[n];
} else {
if (n < 2) {
cache[n] = n; // Cache the base case result
return n;
} else {
cache[n] = fib(n - 1) + fib(n - 2);
return cache[n];
}
}
};
}
const fasterFib = fibonacciMaster();
console.log(fasterFib(10)); // 55
console.log(fasterFib(50)); // 12586269025
```
## 7. JavaScript Let vs Var vs Const
Using let: It has block scope. So it is not accessible outside of a block i.e. curly braces {}
```
function start() {
for(let counter = 0; counter < 5; counter++) {
console.log(counter);
}
//console.log(counter)//ReferenceError: counter is not defined
}
start();
```
Output:
0
1
2
3
4
Using var: It has function scope. It's scope is not limited to the block in which it is defined but is limited to the function scope.
```
function start() {
for(var counter = 0; counter < 5; counter++) {
console.log(counter);
}
console.log(counter)//last value of counter after the for loop ends i.e. value 5
}
start();
```
Output:
0
1
2
3
4
5
Another example of var:
```
function start() {
for(var counter = 0; counter < 5; counter++) {
if(true) {
var color = 'red';
}
}
console.log(color)
}
start();
```
- When we use var outside of a function, it creates a global variable and attaches that global variable window object in browser. variables declared with let (or const) do not get attached to the global object.
- window object is central, suppose we are using a third party library and it has a variable with a same name and so that variable can override our variable. Hence, we should avoid adding stuff to window object.
So, Avoid using var keyword.
Key Differences Between var and let:
Scope:
- var is function-scoped, meaning it is accessible throughout the entire function in which it is declared.
- let(& const) is block-scoped, meaning it is only accessible within the block (enclosed by {}) where it is declared.
Hoisting: Check 8. headline to understand hoisting further.
- Variables declared with var are hoisted to the top of their scope and initialized with undefined.
- Variables declared with let(& const) are also hoisted, but they are not initialized. Accessing them before declaration results in a ReferenceError.
Example Illustrating Scope and Hoisting:
```
function testVar() {
console.log(varVar); // Outputs: undefined (due to hoisting)
var varVar = 'I am var';
console.log(varVar); // Outputs: 'I am var'
}
function testLet() {
// console.log(letVar); // Would throw ReferenceError (temporal dead zone)
let letVar = 'I am let';
console.log(letVar); // Outputs: 'I am let'
}
testVar();
testLet();
```
Const keyword:
- The const keyword in JavaScript is used to declare variables that are constant, meaning their value cannot be reassigned after they are initialized.
- The binding (the reference to the value) of a const variable cannot be changed, but this does not mean the value itself is immutable. For example, if the value is an object or an array, its properties or elements can still be modified.
```
const y = 5;
// y = 10; // TypeError: Assignment to constant variable.
const obj = { name: 'Alice' };
obj.name = 'Bob'; // This is allowed
console.log(obj.name); // Outputs: 'Bob'
```
## 8. Hoisting
In JavaScript, hoisting is a concept where variable and function declarations are moved to the top of their containing scope during the compilation phase, before the code is executed. This means that regardless of where variables and functions are declared within a scope, they are treated as if they are declared at the top.
Scope in JavaScript refers to the visibility and accessibility of variables, functions, and objects in particular parts of your code during runtime
Variable Hoisting:
- When variables are declared using var, let, or const, the declaration (not the initialization) is hoisted to the top of the scope.
- However, only the declaration is hoisted, not the initialization. This means that variables declared with var are initialized with undefined whereas variables declared with let or const are not initialized until the actual line of code where the declaration is made.
- Variables declared with let or const are hoisted to the top of their block scope, but they are not initialized until their actual declaration is evaluated during runtime. This is known as the "temporal dead zone" (TDZ).
```
console.log(y); // ReferenceError: Cannot access 'y' before initialization
let y = 10;
```
Function Hoisting:
- Function declarations are completely hoisted, including both the function name and the function body.
- This allows you to call a function before it is declared in the code.
```
foo(); // "Hello, I'm John Wick!"
function getName() {
console.log("Hello, I'm John Wick!");
}
```
- Function expressions (functions assigned to variables) are not hoisted in the same way. Only the variable declaration is hoisted, not the function initialization.
```
getName(); // Error: getName is not a function
var getName = function() {
console.log("Hello, I'm John Wick!");
};
```
## 9. IIFE (Immediately Invoked Function Expression)
An Immediately Invoked Function Expression (IIFE) is a function in JavaScript that runs as soon as it is defined. It is a common JavaScript pattern used to create a private scope and avoid polluting the global namespace.
Here is the basic structure of an IIFE:
```
(function() {
// Your code here
})();
```
- The function is defined within parentheses () to treat it as an expression, and it is immediately invoked with another set of parentheses ().
```
(function() {
console.log("This is an IIFE");
})();
```
Why Use IIFE?
- Avoid Global Variables: IIFEs help in avoiding global variables by creating a local scope.
- Encapsulation: They encapsulate the code, making it self-contained.
- Immediate Execution: Useful for running setup code for testing on local that should not be run again.
Examples:
With Parameters
```
(function(a, b) {
console.log(a + b);
})(5, 10);
```
Returning Values:
```
let result = (function() {
return "Hello, World!";
})();
console.log(result); // Outputs: Hello, World!
```
Using Arrow functions:
```
(() => {
console.log("This is an IIFE with arrow function");
})();
```
## Q. What does this code log out?
```
for (var counter = 0; counter < 3; counter++) {
//Closure as it depends on variable outside of it's scope.
const log = () => {
console.log(i);
}
setTimeout(log, 100);
}
```
Output:
3
3
3
- var has global scope. with var we are mutating over and over again.
- As we are using a closure, it keeps reference to counter variable in heap memory where it can be used later after timeout is achieved.
- The time the setTimeout callbacks (the log functions) execute, the counter variable in the outer scope has been incremented to 3. Thus, each log function logs the final value of counter, which is 3.
```
for (var let = 0; counter < 3; counter++) {
//Closure as it depends on variable outside of it's scope.
const log = () => {
debugger;
console.log(i);
}
setTimeout(log, 100);
}
```
Output:
0
1
2
- let is block scope. with let we are creating a variable that is scoped to for loop. i.e. it is local to the for loop and cannot be accessed outside of it.
- In case of let, closure is capturing the log function with counter variable for each iteration of loop which is 0, 1 and 2.
- Closure and Execution Context: Because let is block-scoped, each log function captures a unique counter variable from its respective iteration of the loop. Therefore, when each log function executes after 100 milliseconds, it logs the value of counter as it existed at the time of its creation.
| rajatoberoi |
1,897,174 | Empowering Fitness with Twilio: Your Personal GymBuddy for Seamless Communication and Progress Tracking! | This is a submission for Twilio Challenge v24.06.12 What I Built ... | 0 | 2024-06-22T17:11:58 | https://dev.to/dailydev/empowering-fitness-with-twilio-your-personal-gymbuddy-for-seamless-communication-and-progress-tracking-147i | devchallenge, twiliochallenge, ai, twilio |
*This is a submission for [Twilio Challenge v24.06.12](https://dev.to/challenges/twilio)*
## What I Built
### GymBuddy
GymBuddy is a web application designed to help fitness enthusiasts track their workout performance and nutritional intake efficiently. Whether you're a beginner looking to establish a fitness routine or a seasoned athlete aiming to optimize your training, GymBuddy provides essential tools and insights to support your fitness journey.
### Key Features
- **Performance Metrics**: Track sets, reps, workout duration, and calories burned across different exercises.
- **Nutrition Tracking**: Monitor meals consumed throughout the day to maintain a balanced diet.
- **Daily Quotes**: Get inspired with daily motivational quotes to keep you motivated.
- **Interactive Charts**: Visualize your progress with interactive charts showing performance trends over time.
### Technologies Used
- **Frontend**: React.js, Chakra UI
- **Backend**: Flask
- **External APIs**: Twilio Api for whatsapp messaging and Cohere Api for AI responses
## Demo
{% embed https://www.youtube.com/embed/dm1YYX46k3Q %}
## Twilio and AI
I utilized the Cohere API to generate AI-driven content, such as daily motivational quotes and personalized workout plans based on user input. When a user fills out the form, a workout plan is dynamically generated, including meal suggestions.
For communication, I integrated the Twilio API to send messages. Upon completing their workout, users can enter details in a specific format like "10 10 50 200". Twilio then sends this data to a Flask server via its API. The Flask server interprets the message to update the dashboard with details such as 10 reps, 10 sets, 50 minutes, and 200 calories burned.
I could not have achieved this functionality without Twilio Kudos to Twilio team.
Also I had already written [Blog](https://devspotlight.hashnode.dev/message-delivery-with-twilio-api-and-google-sheets) around Twilio so I had little experience with Twilio API and Whatsapp business API.
I wanted to use Twilio Whatsapp business API but time was less as it takes verification so I sticked to using Whatsapp Sandbox.
### Getting Started
To get started with GymBuddy, and follow these steps:
1.You can try it out by scanning the QR Code in the image or by texting the code **join four-mental** to the number +14155238886 on WhatsApp.
Once that is done clone the repository.
## Source code
{% embed https://github.com/AdityaGupta20871/GymBud
%}
## Additional Prize Categories
<!-- Does your submission qualify for any additional prize categories
`Twilio Times Two`: My usage of Twilio's Whatsapp Messaging API for outbound messages and the Twilio REST Client for handling incoming messages qualifies your project under the Twilio Times Two category.
`Impactful Innovators`: My project, GymBuddy, innovatively integrates the Cohere API and Twilio to revolutionize fitness tracking and engagement. Using Cohere, GymBuddy generates personalized motivational quotes and custom workout plans. Twilio facilitates seamless communication, enabling users to log workout details via simple text messages and receive instant updates on their progress.
<!-- Thanks for participating! → | dailydev |
1,897,172 | Visualize and explain byte sequences with byte-diagram | Hey everyone! I'm excited to introduce you to a new command-line tool I've been working on called... | 0 | 2024-06-22T17:11:24 | https://dev.to/yanujz/visualize-and-explain-byte-sequences-with-byte-diagram-201e | cli, tools, asciiart | Hey everyone!
I'm excited to introduce you to a new command-line tool I've been working on called byte-diagram. This tool allows you to visualize byte sequences using ASCII art, making it easier to understand and analyze hexadecimal data.
**What is `byte-diagram`?**
`byte-diagram` is a Python-based command-line utility designed for visualizing byte sequences. It takes a hexadecimal string as input and generates an ASCII diagram that represents each byte and its position in the sequence.
**How does it work?**
Using byte-diagram is straightforward. You simply provide it with a hexadecimal string as an argument, and it will generate a diagram showing each byte's position and value in a sequential manner. Here's an example:
```
$./byte-diagram.py -s "00 01 02" -d "Field 0" "Field 1" "Field 2"
------------> Field 0
/ -------> Field 1
| / --> Field 2
| | /
| | |
0x00 0x01 0x02
```
**Where do you find it?**
You can find `byte-diagram` on GitHub [here](https://github.com/Yanujz/byte-diagram).
**Contribution**
Contributions to `byte-diagram` are welcome! Whether you want to add new features, improve documentation, or fix bugs, feel free to fork the repository and submit a pull request. | yanujz |
1,897,169 | 🎉 Celebrating Cisco Codathon 2020! 🚀 | Hey Everyone! I'm excited to share some amazing news – I participated in and successfully completed... | 0 | 2024-06-22T17:02:38 | https://dev.to/bvidhey/celebrating-cisco-codathon-2020-21a3 | Hey Everyone!
I'm excited to share some amazing news – I participated in and successfully completed Cisco Codathon 2020! 🌟 It was an exhilarating experience where I collaborated with brilliant minds to tackle real-world challenges using innovative tech solutions.
During the Codathon, we explored cutting-edge technologies, honed our problem-solving skills, and built solutions that could make a meaningful impact in today's digital landscape.
A heartfelt thanks to my team members for their dedication and teamwork, as well as to Cisco for organizing such an incredible event. This journey has been nothing short of inspiring, and I'm eager to continue pushing boundaries and exploring new opportunities in the tech world.
Cheers to innovation, collaboration, and the thrill of coding! 🎉 | bvidhey | |
1,897,168 | Scalability in React Native: Ensuring Future- Proof Applications | Scalability in React Native: Ensuring Future-Proof Applications Scalability is a critical aspect of... | 0 | 2024-06-22T17:00:13 | https://dev.to/nmaduemmmanuel/scalability-in-react-native-ensuring-future-proof-applications-569f | **Scalability in React Native: Ensuring Future-Proof Applications**
Scalability is a critical aspect of modern application development, especially when it comes to mobile apps built with React Native. Scalability refers to the ability of an app to handle a growing number of users or transactions without compromising performance or user experience.
**Why is Scalability Important in React Native?**
React Native is a popular framework for developing cross-platform mobile applications using JavaScript and React. Its importance for scalability lies in several factors:
- **Code Reusability**: React Native allows developers to write once and deploy on both iOS and Android platforms, which means scalability needs to be considered for multiple ecosystems.
- **Performance**: As the user base grows, the app must maintain its performance without lag or crashes.
- **Maintenance**: Scalable code is easier to maintain and update, which is crucial for the longevity of an app.
- **Resource Management**: Efficient use of device resources such as memory and CPU is essential for scalability.
**Coding Examples for Scalable Practices in React Native:**
To ensure scalability in your React Native applications, consider the following practices:
*1. State Management:*
Using a robust state management solution like Redux or Context API can help manage state more efficiently in large-scale applications.
```javascript
import { createStore } from 'redux';
// Action
const increment = () => {
return {
type: 'INCREMENT'
};
};
// Reducer
const counter = (state = 0, action) => {
switch (action.type) {
case 'INCREMENT':
return state + 1;
default:
return state;
}
};
// Store
let store = createStore(counter);
// Display it in the console
store.subscribe(() => console.log(store.getState()));
// Dispatch
store.dispatch(increment());
```
*2. Component Optimization:*
Optimizing components with `React.memo` and `shouldComponentUpdate` can prevent unnecessary re-renders.
```javascript
import React, { memo } from 'react';
const MyComponent = memo(function MyComponent(props) {
/* render using props */
});
```
*3. Lazy Loading:*
Lazy loading components with `React.lazy` and `Suspense` can improve initial load times and overall performance.
```javascript
import React, { Suspense, lazy } from 'react';
const LazyComponent = lazy(() => import('./LazyComponent'));
function MyComponent() {
return (
<Suspense fallback={<div>Loading...</div>}>
<LazyComponent />
</Suspense>
);
}
```
*4. Efficient Networking:*
Using libraries like Axios for network requests can help manage API calls more effectively.
```javascript
import axios from 'axios';
axios.get('/user?ID=12345')
.then(function (response) {
// handle success
console.log(response);
})
.catch(function (error) {
// handle error
console.log(error);
});
```
**Advanced Strategies for Scalability in React Native**
To further enhance the scalability of your React Native applications, consider implementing the following advanced strategies:
*5. Modular Architecture:*
Designing your app with a modular architecture can greatly improve scalability. It allows individual features or components to be developed, tested, and debugged independently.
```javascript
// Example of a modular file structure
src/
|-- components/
| |-- Button.js
| |-- Card.js
|-- screens/
| |-- HomeScreen.js
| |-- ProfileScreen.js
|-- utils/
| |-- api.js
| |-- helpers.js
```
*6. Continuous Integration/Continuous Deployment (CI/CD):*
Implementing CI/CD pipelines can streamline the development process, making it easier to scale your team and codebase.
```yaml
# Example of a CI/CD configuration file for React Native
name: Build and Deploy
on:
push:
branches: [ main ]
jobs:
build:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Install Dependencies
run: npm install
- name: Run Tests
run: npm test
- name: Build App
run: npm run build
deploy:
needs: build
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Deploy to App Store and Google Play
run: ./deploy.sh
```
*7. Performance Monitoring and Analytics:*
Integrating performance monitoring tools like Flipper or Reactotron can help identify bottlenecks as your app scales.
```javascript
// Example of integrating Flipper in a React Native app
if (__DEV__) {
const { connectToDevTools } = require('react-devtools-core');
connectToDevTools({
hostname: 'localhost',
port: 8097,
});
}
```
*8. Scalable Backend Services:*
Ensure that your backend services are scalable to match the growth of your front-end application. Consider serverless architectures or containerization for backend scalability.
```javascript
// Example of using AWS Lambda for a serverless backend function
exports.handler = async (event) => {
// Your serverless function logic here
};
```
**Conclusion:**
Scalability is not an afterthought; it's a fundamental consideration from the start of your React Native project. By adopting scalable practices early on, you ensure that your application remains robust, performant, and maintainable as it grows. Remember that scalability is about preparing for success—anticipating more users, more data, and more interactions. With these scalable practices in place, your React Native app will be well-positioned to thrive in an ever-evolving mobile landscape. | nmaduemmmanuel | |
1,897,167 | AWS Certifications | 🚀 Exciting Announcement: Celebrating AWS Certifications! 🌟 Hey Dev Community! Certificates Link :... | 0 | 2024-06-22T16:59:41 | https://dev.to/bvidhey/aws-certifications-5ejc | aws, awschallenge | 🚀 Exciting Announcement: Celebrating AWS Certifications! 🌟
Hey Dev Community!
**Certificates Link :** [AWS-Certifications](https://github.com/Vidhey012/My-Certifications/tree/main/Aws)
I'm thrilled to share a major milestone in my journey – I've recently earned several AWS certifications! 🎉 These certifications represent countless hours of dedication and a deep dive into cloud technologies.
Each certification has broadened my expertise in AWS services, infrastructure management, and cloud security. It's a testament to my commitment to mastering cloud computing and advancing in my career as a developer.
I owe a huge thanks to my mentors, peers, and this amazing community for their support and guidance throughout this journey. 🙌
Let's continue to learn, grow, and innovate together! 💪
| bvidhey |
1,897,166 | Who Am I? 🚀 | Hello Dev Community! 👋 My name is Vidhey Bhogadi, and I am thrilled to be part of this amazing... | 0 | 2024-06-22T16:46:35 | https://dev.to/bvidhey/who-am-i-4ap | Hello Dev Community! 👋
My name is Vidhey Bhogadi, and I am thrilled to be part of this amazing community. Let me take a moment to introduce myself.
My Background 🌐
I am a full-stack developer and a self-taught tech enthusiast. Over the years, I have immersed myself in the world of technology, constantly learning and evolving. My journey in tech started with curiosity and has blossomed into a passion for building innovative solutions.
What I Do 💻
As a full-stack developer, I work with a variety of technologies to create comprehensive and efficient applications. My skill set includes:
Frontend: HTML, CSS, JavaScript, React, Angular
Backend: Node.js, Express, Django
Databases: MySQL, PostgreSQL, MongoDB
Others: Git, Docker, CI/CD, Cloud Services (AWS, Azure)
I enjoy working on projects that challenge me and allow me to grow. Whether it's developing a responsive web application or optimizing backend performance, I am always up for the task.
My Passion 🌟
I am passionate about:
Learning New Technologies: The tech field is always evolving, and I love staying updated with the latest trends.
Collaborating: I believe that great things are built through teamwork. I am always open to collaborating on exciting projects.
Problem-Solving: I enjoy tackling complex problems and finding efficient solutions.
Looking Forward 🚀
I am excited to connect with fellow developers, share my knowledge, and learn from this vibrant community. If you're working on interesting projects or looking for a collaborator, feel free to reach out. Let's build something amazing together!
Thank you for taking the time to read about me. Looking forward to engaging with you all!
Best,
Vidhey Bhogadi.
| bvidhey | |
1,897,163 | Guia Básico para tratar dados com Pandas em Python | Olá, esse guia tem como objetivo apresentar algumas formas de tratamento de dados com a biblioteca... | 0 | 2024-06-22T16:42:01 | https://dev.to/rvinicius396g/guia-basico-para-tratar-dados-com-pandas-em-python-4f2f | pandas, python, dataframe, datascience | Olá, esse guia tem como objetivo apresentar algumas formas de tratamento de dados com a biblioteca pandas do Python, umas das mais utilizadas por profissionais na área de dados.
Primeiro, vamos fazer a importação das respectivas bibliotecas que utilizaremos
`
import pandas as pd
import matplotlib.pylab as plt
#Agora, faremos a leitura da nossa base de dados
url= "https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-DA0101EN-SkillsNetwork/labs/Data%20files/auto.csv"
`
Note que, ao fazermos a importação da base de dados, a mesma não tem cabeçalho, então para criar o cabeçalho faremos o processo abaixo:
`
#Criacao do cabeçalho em uma lista com seus respectivos valores
cabecalho = ["symboling","normalized-losses","make","fuel-type","aspiration", "num-of-doors","body-style",
"drive-wheels","engine-location","wheel-base", "length","width","height","curb-weight","engine-type",
"num-of-cylinders", "engine-size","fuel-system","bore","stroke","compression-ratio","horsepower",
"peak-rpm","city-mpg","highway-mpg","price"]
#Adicionando o cabeçalho ao dataset que não tem cabeçalho + leitura do dataset no formato csv
df = pd.read_csv(url, names = cabecalho)
`
Nesse exemplo, o valores pendentes vão estar como “?” (interrogação). Alguma dúvidas podem surgir: o que fazer com esses valores que não vieram ? Como tratar ? Posso deletar ? …
A resposta é: Depende.. Existe algumas técnicas que podemos utilizar:
- Apagar a coluna completa que está sem as informações;
- Apagar a linha completa que está sem as informações;
- Substituir os dados pela média/frequência/etc;
Essas são algumas, existem várias outras forma de lidarmos com esses dados pendentes
`
#Para visualizar alguns dados,usarmos o comando abaixo
df.head()
`
Note que, como havia informado anteriormente, alguns dados pendentes estão como “?” , agora, vamos substituir esses valores por NaN (Not a number)
`
import numpy as np
#O comando abaixo substituirá ? por NaN;
# O parâmetro inplace = True, salva as alterações realizadas no dataframe que estamos usando (df)
df.replace('?', np.nan, inplace = True)
#Ao executar o head(), você notará que o símbolo de interrogação foi substituido por NaN
df.head()
`
## Tratando (substituindo) os dados pendentes
No algoritmo abaixo, iremos substituir os valores NaN da coluna normalized-losses pela média, depois que convertermos para o tipo float
`avg_norm_loss = df["normalized-losses"].astype("float").mean(axis=0)
print("Média da normalized-losses:", avg_norm_loss)
#substituir os valores NaN da coluna normalized-losses pela média
df["normalized-losses"].replace(np.nan, avg_norm_loss, inplace=True)
`
E assim podemos dar prosseguimento para todas as outras colunas que tiverem informações pendentes. Algumas dúvidas podem surgir, porque foi feita a conversão da normalized-losses para float ? A respota é: Normalized-losses é do tipo objetct, que seria semelhante a “string”, dessa forma não é possível realizarmos operações matemáticas nesse tipo de objeto, por isso fizemos a conversão.
`avg_bore=df['bore'].astype('float').mean(axis=0)
print("Média da bore:", avg_bore)
#Substituindo valores NaN da coluna Bore pela média
df["bore"].replace(np.nan, avg_bore, inplace=True)
#Substituindo valores NaN da coluna stroke pela média
stroke_mean = df['stroke'].astype('float').mean(axis=0)
df['stroke'].replace(np.nan, stroke_mean, inplace=True)
avg_horsepower = df['horsepower'].astype('float').mean(axis=0)
#Substituindo os valores NaN da coluna 'horsepower' pela média
df['horsepower'].replace(np.nan, avg_horsepower, inplace=True)
`
No exemplo abaixo, vamos deletar todos os registros (linhas) que não tem dados da coluna price:
`df.dropna(subset=["price"], axis=0, inplace=True)`
Algumas informações que podem ser importantes:
- axis = 0 >> O zero refere-se as linha .\. 1 refere-se as colunas
- inplace >> Salva as alterações realizadas no dataframe
## Conversão de dados
Como já foi apresentado anteriormente, outra parte fundamental do tratamento dos dados são os tipos de dados na biblioteca pandas: object, float, int,datetime, etc. Afinal, não conseguimos calcular a média de uma variável do tipo string, certo ? Então, precisamos converter o seu data type para que isso seja possível.
Para analisarmos os tipos de dados em pandas, podemos usar a função dtype
`#Verificando o datype em python
#Ela retornara o datatype de todas as variáveis (colunas) do nosso data frame
df.dtypes
# Abaixo, realizamos a conversão dos data types para float, int e atribuimos a conversão a propria
# variável para "salvar" as alterações. Passamos no parâmetro astype("valordavariável")
df[["bore", "stroke"]] = df[["bore", "stroke"]].astype("float")
df[["normalized-losses"]] = df[["normalized-losses"]].astype("int")
df[["price"]] = df[["price"]].astype("float")
df[["peak-rpm"]] = df[["peak-rpm"]].astype("float")`
Antes de fazer a conversão, sempre procure análisar o data type atual da variável com (dtypes) e analisar novamente após a conversão, para garantir que a alteração foi realizada com sucesso.
> Esse foi um guia básico e prático de como trabalhar com tratamento de dados utilizando a biblioteca Python, as informações disponibilizadas aqui foram colhidas do curso de Análise de dados com Python — IBM da Cousera, recomendo a todos que estão estudando e procurando ampliar o seu conhecimento nessa área darem uma olhada ou até mesmo realizarem o curso, que apesar de básico é muito bom ! Obrigado a todos por lerem até aqui !
for column in missing_data.columns.values.tolist():
print(column)
print (missing_data[column].value_counts())
print("") | rvinicius396g |
1,896,287 | O que é Blochchain e como a tecnologia funciona? | Como Blockchain Funciona? Blockchain é uma tecnologia que trabalha como um sistema de... | 0 | 2024-06-22T16:35:24 | https://dev.to/starch1/o-que-e-blochchain-e-como-a-tecnologia-funciona-24b0 | blockchain, begginer, programmers, braziliandevs |
### Como Blockchain Funciona?
Blockchain é uma tecnologia que trabalha como um sistema de registro distribuído e descentralizado. A tecnologia fundamentalmente cria um registro digital de transações compartilhado por uma rede de computadores. Cada transação é agrupada em blocos, que são conectados ao bloco anterior, formando uma cadeia contínua de blocos, daí o nome "blockchain". Essa estrutura permite a manutenção de um histórico imutável de transações, proporcionando transparência e confiança sem a necessidade de intervenção de autoridades superiores(Como bancos).
### Descentralização
Uma das grande vantagens do blockchain é a descentralização. Ao contrário dos sistemas tradicionais que dependem de uma entidade central para validar transações, o blockchain permite que múltiplos participantes na rede verifiquem e registrem transações. Isso melhora a segurança e a transparência, já que não há um único ponto de falha que possa comprometer toda a rede. A descentralização também promove a democratização do controle, onde todos os participantes têm acesso igual à informação e ao poder de validação.
### Redes Peer-to-Peer (P2P)
Blockchain funciona em redes peer-to-peer (P2P), onde cada nó possui uma cópia completa do registro digital. Isso elimina a necessidade de uma autoridade central e permite que transações sejam conduzidas diretamente entre os participantes da rede. As redes P2P são fundamentais para a descentralização e a resistência do blockchain, pois distribuem o poder computacional e os dados entre todos os participantes, tornando a rede mais robusta e menos suscetível a ataques.
### Proof of Work
O Proof of Work é um mecanismo usado por algumas blockchains, como o Bitcoin, para validar e processar transações. Neste processo, os nós da rede competem pra resolver problemas matemáticos complexos. O primeiro nó a resolver o problema é recompensado com criptomoedas e adiciona um novo bloco à blockchain. Esse método intensivo em recursos computacionais garante a segurança da rede. Contudo, ele também é criticado por seu alto consumo de energia e por contribuir para a centralização da mineração em áreas com eletricidade barata.
### Proof of Stake
Em resposta às limitações do Proof of Work, algumas blockchains adotaram o Proof of Stake como mecanismo de consenso. No Proof of Stake, os validadores são escolhidos com base na quantidade de criptomoeda que possuem e estão dispostos a "apostar" como garantia de seu compromisso com a rede. Esse método é mais eficiente em termos energéticos e reduz o risco de centralização, já que não depende de poder computacional para validar transações.
### Funções de Criptografia Hash
As funções de criptografia hash atual na segurança de redes blockchain. Elas transformam dados de tamanho variável em uma sequência de comprimento fixo, conhecida como hash. Isso garante que cada bloco na blockchain seja único e identificável, proporcionando integridade e segurança aos dados. Exemplo de algoritmo hash bastante usado SHA-256. Os hashes são fundamentais para a estrutura de dados do blockchain, garantindo que qualquer alteração em um bloco seja facilmente detectável.
### SHA-256 Hash
SHA-256 é um algoritmo de hash criptográfico essencial em várias blockchains, incluindo o Bitcoin. Ele gera hashes de 256 bits e é vital para garantir a segurança e a integridade da blockchain. Qualquer modificação nos dados de um bloco resulta em um hash completamente diferente, facilitando a detecção de fraudes ou alterações não autorizadas. O uso do SHA-256 contribui para a robustez do sistema, tornando as transações seguras contra tentativas de falsificação e corrupção.
### Smart Contracts
Smart contracts, são programas que executam automaticamente os termos de um contrato quando certas condições são atendidas. Eles são armazenados e executados no blockchain, o que garante transparência e imutabilidade. Os smart contracts tem potencial para revolucionar várias indústrias ao automatizar processos que tradicionalmente requerem intermediários, reduzindo custos e aumentando a eficiência.
### Casos de Uso
Além das criptomoedas, o blockchain possui uma ampla gama de aplicações potenciais. Exemplos incluem registros médicos eletrônicos que garantem privacidade e acessibilidade, cadeias de suprimentos transparentes que rastreiam produtos desde a origem até o consumidor final, e sistemas de votação eletrônica seguros que aumentam a confiança pública. A capacidade do blockchain de oferecer segurança sem intermediários tem o potencial de transformar vários segmentos. No setor financeiro, contratos inteligentes podem automatizar processos como empréstimos e seguros, enquanto em governos, podem garantir a integridade dos processos eleitorais e da administração pública.
| starch1 |
1,897,159 | Excited to Join and Learn: My Journey in Tech | Hi everyone! I'm thrilled to join this vibrant community. My name is Ruturaj Jadhav, and I wanted to... | 0 | 2024-06-22T16:24:26 | https://dev.to/ruturajj/excited-to-join-and-learn-my-journey-in-tech-59b9 | letsconnect, beginners, programming, java | Hi everyone!
I'm thrilled to join this vibrant community. My name is Ruturaj Jadhav, and I wanted to share a bit about my journey in tech.
I started with Java, and over time, I developed a strong interest in Data Structures and Algorithms (DSA) and Artificial Intelligence (AI). Currently, I'm focusing on enhancing my skills in these areas and exploring the exciting potential of AI.
I'm eager to learn from all of you, share my experiences, and collaborate on innovative projects. If you're working on anything interesting, I would love to learn from you all.
Looking forward to connecting with you all,
| ruturajj |
1,897,157 | Enable Touch ID Authentication for sudo on macOS Sonoma 14.x | Operating Environment: OS: MacOS Sonoma 14.5 Device: M1 MacBook Pro ... | 0 | 2024-06-22T16:22:46 | https://dev.to/siddhantkcode/enable-touch-id-authentication-for-sudo-on-macos-sonoma-14x-4d28 | macos, touchid, security, productivity | ### Operating Environment:
- **OS:** MacOS Sonoma 14.5
- **Device:** M1 MacBook Pro
## Explanation
In macOS Sonoma, a new method has been introduced to enable Touch ID when running `sudo` commands, making it more persistent across system updates. Previously, editing the `/etc/pam.d/sudo` file was necessary, but these changes would often revert after an update, requiring reconfiguration. With Sonoma, the settings can be added to a separate file `/etc/pam.d/sudo_local`, which isn't overwritten during updates, allowing Touch ID to remain enabled for `sudo` commands consistently.
## Steps to Enable Touch ID for `sudo`
### 1. Create and Edit the Configuration File
Create a new configuration file based on the template provided in macOS Sonoma.
```sh
sudo cp /etc/pam.d/sudo_local.template /etc/pam.d/sudo_local
```
Edit the newly created file with your preferred text editor:
```sh
sudo vim /etc/pam.d/sudo_local
```
In the file, locate the following line, Uncomment it by removing the `#`:
```diff
- #auth sufficient pam_tid.so
+ auth sufficient pam_tid.so
```
### Alternative Method Using `sed` and `tee`
You can achieve the same result with a single command using `sed` and `tee`:
```sh
sed -e 's/^#auth/auth/' /etc/pam.d/sudo_local.template | sudo tee /etc/pam.d/sudo_local
```
### 2. Confirm the Operation
Open a new terminal session and run a `sudo` command to test the setup:
```sh
sudo ls
```
You should be prompted to authenticate using Touch ID. If the command executes after Touch ID authentication, the setup is complete.
<img width="270" alt="Screenshot 2024-06-22 at 4 48 00 PM" src="https://gist.github.com/assets/55068936/ce9c32f4-a1e2-44bb-99e2-7a31af15309f">
### Background
Previously, enabling Touch ID for `sudo` required modifying `/etc/pam.d/sudo`, but these changes did not persist through macOS updates. By leveraging the new `/etc/pam.d/sudo_local` configuration in macOS Sonoma, we can ensure that Touch ID settings for `sudo` remain intact even after system updates.
The `/etc/pam.d/sudo` file now includes the following:
```plaintext
# sudo: auth account password session
auth include sudo_local
auth sufficient pam_smartcard.so
auth required pam_opendirectory.so
account required pam_permit.so
password required pam_deny.so
session required pam_permit.so
```
This configuration ensures that the settings in `/etc/pam.d/sudo_local` are loaded and used, maintaining Touch ID functionality for `sudo` commands.
Please note that for macOS versions earlier than Sonoma, manual editing of `/etc/pam.d/sudo` is still required to enable Touch ID for `sudo` commands. | siddhantkcode |
1,897,115 | Leave Switch Behind: The Power of Maps and Patterns in JavaScript Development | In this post, we'll explore the limitations of using switch statements in JavaScript and discuss... | 0 | 2024-06-22T16:19:18 | https://dev.to/waelhabbal/leave-switch-behind-the-power-of-maps-and-patterns-in-javascript-development-2hhj | development, solidprinciples, webdev, javascript | In this post, we'll explore the limitations of using `switch` statements in JavaScript and discuss alternative approaches using maps and patterns. We'll cover how maps can be used for dynamic lookups and how patterns can be used to encapsulate complex logic.
**The Case Against Overusing Switch Statements**
While `switch` statements are efficient for simple value comparisons, they have several limitations:
* Readability: Long chains of case statements become difficult to read and debug.
* Extensibility: Adding new cases requires modifying the existing structure.
* Default Handling: The default case can become a catch-all, potentially hiding errors.
**Enter Maps: Key-Value Pairs for Dynamic Lookups**
Maps (introduced in ES6) offer a powerful alternative:
* Key-Value Pairs: Store data as associations between keys and values.
* Dynamic Lookups: Retrieve values efficiently based on keys.
* Flexibility: Easily add, remove, or modify key-value pairs without altering the core logic.
Example: User Role Permissions (Map vs. Switch)
Using Switch:
```javascript
function getUserPermissions(role) {
switch (role) {
case 'admin':
return ['read', 'write', 'delete'];
case 'editor':
return ['read', 'write'];
case 'reader':
return ['read'];
default:
return [];
}
}
```
Using Map:
```javascript
const permissionsMap = new Map([
['admin', ['read', 'write', 'delete']],
['editor', ['read', 'write']],
['reader', ['read']],
]);
function getUserPermissions(role) {
return permissionsMap.get(role) || []; // Return empty array for missing roles
}
```
**Patterns for Encapsulating Behavior**
Sometimes, complex logic within a `switch` case deserves its own reusable function. Here's how patterns come in:
* Strategy Pattern: Define an interface for different behavior types and create concrete implementations for each case.
* Command Pattern: Encapsulate actions within objects, allowing decoupled execution.
Example: Discount Calculations (Pattern vs. Switch)
Using Switch:
```javascript
function calculateDiscount(productType, quantity) {
switch (productType) {
case 'electronics':
return quantity > 5 ? 0.1 : 0.05;
case 'clothing':
return 0.1;
default:
return 0;
}
}
```
Using Strategy Pattern:
```javascript
interface DiscountStrategy {
calculateDiscount(quantity: number): number;
}
class ElectronicsDiscount implements DiscountStrategy {
calculateDiscount(quantity: number) {
return quantity > 5 ? 0.1 : 0.05;
}
}
class ClothingDiscount implements DiscountStrategy {
calculateDiscount() {
return 0.1;
}
}
function calculateDiscount(productType: string, quantity: number) {
const strategies = {
electronics: new ElectronicsDiscount(),
clothing: new ClothingDiscount(),
};
return strategies[productType]?.calculateDiscount(quantity) || 0;
}
```
**Applying SOLID Principles**
* Single Responsibility Principle: switch often mixes data logic with control flow. Maps and patterns help isolate responsibilities.
* Open/Closed Principle: Maps and patterns allow extending behavior without modifying existing code.
* Liskov Substitution Principle: Patterns like Strategy ensure interchangeable behavior based on interfaces.
* Interface Segregation Principle: Maps provide a clean interface for data lookup.
* Dependency Inversion Principle: Patterns encourage relying on abstractions (interfaces) rather than concrete implementations (switch).
Conclusion:
By embracing maps and patterns, you can improve code readability and maintainability, enhance flexibility for future changes, and adhere to SOLID principles for better design. Remember, the best approach depends on the complexity of your logic. Consider using switch for simple cases, but for more intricate scenarios, maps and patterns are more suitable alternatives. | waelhabbal |
1,897,149 | If to be or not to be is the question, ternary operator is the answer | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-22T16:18:13 | https://dev.to/ahad23/if-to-be-or-not-to-be-is-the-question-ternary-operator-is-the-answer-1a10 | devchallenge, cschallenge, computerscience, beginners | *This is a submission for [DEV Computer Science Challenge v24.06.12: One Byte Explainer](https://dev.to/challenges/cs).*
## Explainer
Do I jump or duck? If the obstacle is high, jump, if it's low, duck. You need a quick decision. That's what the ternary operator does. Instead of pausing to think, it quickly chooses between two actions based on a condition.
Also huge shoutout to my team member @vedangit !! | ahad23 |
1,897,148 | How to Write an Effective Postmortem: A Use Case Example | In the world of IT and web services, outages and system failures are inevitable. When they occur, a... | 0 | 2024-06-22T16:16:31 | https://dev.to/preciousanyi/how-to-write-an-effective-postmortem-a-use-case-example-57g8 | webdev, beginners, programming, devops | In the world of IT and web services, outages and system failures are inevitable. When they occur, a detailed postmortem is crucial for understanding what went wrong and preventing similar issues in the future. This blog post will guide you through the process of writing an effective postmortem using a real-life use case example.
## Why Write a Postmortem?
A postmortem helps teams:
- Understand the root cause of the issue.
- Document the timeline of events and actions taken.
- Identify areas for improvement and implement preventative measures.
- Communicate transparently with stakeholders about what happened and what will be done to prevent recurrence.
## Structure of a Postmortem
A well-structured postmortem includes the following sections:
- Issue Summary
- Timeline
- Root Cause and Resolution
- Corrective and Preventative Measures
Let’s dive into each section with a use case example.
## Use Case Example
Scenario: An e-commerce website experienced an outage on June 12, 2024. Here’s how the postmortem was structured and written.
### Issue Summary
Duration of the Outage:
Start: June 12, 2024, 09:00 AM (WAT)
End: June 12, 2024, 11:30 AM (WAT)
**Impact:**
The e-commerce website was completely inaccessible, affecting approximately 95% of users. This resulted in lost sales and numerous customer complaints. Over 200 complaints were received within the first hour.
**Root Cause:**
The root cause was a misconfigured database connection pool that led to the exhaustion of available connections, preventing the web application from accessing the database.
### Timeline
09:00 AM (WAT): Issue detected through a monitoring alert indicating high database connection usage.
09:05 AM (WAT): Engineering team notified via pager duty.
09:10 AM (WAT): Initial investigation focused on the web server load and potential DDoS attack.
09:30 AM (WAT): Misleading path: assumed high traffic causing server overload, but server metrics were normal.
09:45 AM (WAT): Database team brought in for further investigation.
10:00 AM (WAT): Identified issue with the database connection pool limits.
10:15 AM (WAT): Escalated to the senior database administrator.
10:45 AM (WAT): Senior DBA confirmed connection pool misconfiguration.
11:00 AM (WAT): Connection pool configuration updated and increased.
11:15 AM (WAT): Web application restarted, and database connections restored.
11:30 AM (WAT): Service fully restored and confirmed stable.
### Root Cause and Resolution
**Root Cause:**
The outage was caused by a configuration error in the database connection pool settings. The connection pool was set to a maximum of 50 connections, which was insufficient for handling peak traffic loads. As a result, the application exhausted all available connections, leading to timeouts and an inability to process any database queries.
**Resolution:**
The database connection pool settings were reviewed and updated. The maximum number of connections was increased to 200, providing enough capacity to handle peak loads. After updating the configuration, the web application was restarted to apply the changes. Monitoring tools confirmed the restoration of normal operations.
### Corrective and Preventative Measures
**Improvements:**
1. **Review and Adjust Connection Pool Settings:** Regularly review and adjust database connection pool settings based on traffic patterns and load testing results.
2. **Enhanced Monitoring:** Implement more granular monitoring for database connection usage to detect issues before they lead to outages.
3. **Automated Scaling:** Explore the implementation of automated scaling solutions for the database connection pool based on real-time demand.
**Tasks:**
1. **Increase Connection Pool Limit:**
Update the database configuration to set a higher default connection pool limit.
2. **Implement Connection Pool Monitoring:**
Add detailed monitoring for connection pool usage and set up alerts for unusual patterns.
3. **Conduct Load Testing:**
Perform load testing to determine optimal connection pool settings for peak traffic.
4. **Automate Scaling Solutions:**
Research and implement an automated scaling solution for the database connection pool to dynamically adjust based on load.
5. **Review Configuration Management:**
Establish a regular review process for all configuration settings related to the database and web application to ensure they meet current traffic demands.
6. **Update Documentation:**
Document the configuration changes and update the runbooks to include steps for adjusting the connection pool settings.
Writing a detailed postmortem helps your team understand the root cause of an outage, improve your processes, and communicate effectively with stakeholders. By following the structured approach outlined in this post and our use case example, you can ensure your postmortems are thorough and actionable, leading to a more resilient and reliable service. | preciousanyi |
1,878,084 | CSRF leads to Open redirect | Reward: 15$ Overview of the Vulnerability Open redirects occur when an application accepts user... | 0 | 2024-06-05T13:49:11 | https://dev.to/c4ng4c31r0/csrf-leads-to-open-redirect-1n5a | **Reward: 15$**
**Overview of the Vulnerability**
Open redirects occur when an application accepts user input that is not validated into the target of a redirection. This input causes a redirection to an external domain, manipulating a user by redirecting them to a malicious site. An open redirect was identified which can impact users' ability to trust legitimate web pages. An attacker can send a phishing email that contains a link with a legitimate business name in the URL and the user will be redirected from the legitimate web server to any external domain. Users are less likely to notice subsequent redirects to different domains when an authentic URL with a valid SSL certificate can be used within the phishing link.
This type of attack is also a precursor for more serious vulnerabilities such as Cross-Site Scripting (XSS), Server-Side Request Forgery (SSRF), Cross-Site Request Forgery (CSRF), or successful phishing attempts where an attacker can harvest users' credentials or gain users' OAuth access by relaying them through an Open Redirection, to a server they control (and can see the inbound requests from).
**Business Impact**
Open redirects can result in reputational damage for the business as customers' trust is negatively impacted by an attacker sending them to a phishing site to extract login credentials, or coercing them to send a financial transaction.
**Steps to Reproduce**
Copy and paste the request below into the burp suite using the "Generate CSRF Poc" functionality, create an HTML page and access it via browser (with the same burp proxy)
**Request**
```
POST /account/change_language HTTP/2
Host: site.com
Cookie: anon-device-id=4c27c635-6a6f-488f-b9a2-9f29173ff515; __cf_bm=Rac7hxpK8o94OYuHBu0gHix5xW0o11y2VhCwxxB_FR4-1707166647-1-AY6CLDec/7yODhPtCT3RC8iWE1Y6m7OqSf1VTqUO7pToGWcrBI9nnOYtOtQ1q4IiaLJ/vu3GKRnCEJyPWMrGaEw=; _mfp_session=kBbELYGofqGXJmZg0zIGaRo5jp7GSfjdTL6s34tbquYJoS4J1VYF1cPZkd6x2Z4xx8R7OKNpX6OJOndQS%2BN4G%2By0pbfitT5oXfov74Cp89zjaFAtX5s7ER0iMSrpbLnlK2jKRHxyusVX2AvU9v5fGc5ApZM4PL3NNdNsmqcxawJcMInSweGvPuOyFMPVYZnsSvkvWS0ARSviiGtwV%2BVM3LlRaG%2F4TgfDEiovbD%2BaszqwpTJntbX9%2Bb%2F3KjwFwitYeifofA8tvKjngXhky36cBVNBDhaToZwxIFnHZp07zLv%2FaHWEKJV4aV11Y3hT%2FGzfJrJjttWtMJicou7FDNX3eXmHhUkJ8zDX22eLGUVTu6w%3D--6me1Z0vPivn%2BoJTV--XkmHgGy679Gl%2FKNsddY7Cw%3D%3D; __Host-next-auth.csrf-token=a139928ae57b8911a5892a7866026aa63815d65196e4e5c6218aaceabb9d4c8d%7C4c4e2344fbf4063da52b2f3ec8315251ff45a9a1bf6e3dfa6018aa87d031a820; __Secure-next-auth.callback-url=https%3A%2F%2Fwww.myfitnesspal.com; AMP_MKTG_2746a27a28=JTdCJTdE; sp_gam_npa=false; dnsDisplayed=undefined; ccpaApplies=true; signedLspa=undefined; _sp_su=false; cf_clearance=xKv4h6PVvCdNz7Ru5gaJgKtAYmWXoaflj0xDqSOggT0-1707166524-1-AWvQd7Iq4gjsZKptQAw3Q+5trsYPEFKOazWRqcbbdG7Z5Wurf9+pCIlWRXfiNiuMG3qUKUj2euDmAeHb2mor0To=; AMP_2746a27a28=JTdCJTIyZGV2aWNlSWQlMjIlM0ElMjJlNWQwMzQ0My0yZTdmLTQ0YmItOTRlNy0zMjllNDI1NGNjZTAlMjIlMkMlMjJzZXNzaW9uSWQlMjIlM0ExNzA3MTY2NTIwNjEwJTJDJTIyb3B0T3V0JTIyJTNBZmFsc2UlMkMlMjJsYXN0RXZlbnRUaW1lJTIyJTNBMTcwNzE2NjU0NTAxMSUyQyUyMmxhc3RFdmVudElkJTIyJTNBNSU3RA==; ccpaConsentAll=true; ccpaReject=false; consentStatus=consentedAll; ccpaUUID=215fdb39-e2eb-4b5e-9042-6f2987093e4b; consentUUID=05f64a74-d7ed-4569-8d6d-303333bf8b4b; _dd_s=logs=0&expire=1707167476513&rum=2&id=fb0f58b6-9182-4e3e-92d0-04445647a54f&created=1707166516408; language_setting=en
Content-Type: application/x-www-form-urlencoded
Content-Length: 203
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Encoding: gzip,deflate,br
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36
authenticity_token=%2BpU4FL6cJuhgBhPzLu2rrTP0n31B1KCplGXuHxvJf7spxrsiuxYbyy3sxYU5YyKZ3EJN%2BdztJQjvJuWkCsTOPQ==&originating_path=http://www.c4ng4c31r0.com%3F&preference[language_setting]=en
```
**CSRF HTML**
```
<html>
<!-- CSRF PoC - generated by Burp Suite Professional -->
<body>
<form action="https://site.com/account/change_language" method="POST">
<input type="hidden" name="authenticity_token" value="+pU4FL6cJuhgBhPzLu2rrTP0n31B1KCplGXuHxvJf7spxrsiuxYbyy3sxYU5YyKZ3EJN+dztJQjvJuWkCsTOPQ==" />
<input type="hidden" name="originating_path" value="http://www.c4ng4c31r0.com" />
<input type="hidden" name="preference[language_setting]" value="en" />
<input type="submit" value="Submit request" />
</form>
<script>
history.pushState('', '', '/');
document.forms[0].submit();
</script>
</body>
</html>
```
PoC:
Generation CSRF PoC
Acessing URL generated with PoC
Redirecting
Reward/Status:
| c4ng4c31r0 | |
1,897,147 | Diferença entre Listas, Tuplas e Dicionários no Python | Como muitos já devem saber, o Python é uma das linguagens que vem crescendo exponencialmente na... | 0 | 2024-06-22T16:15:12 | https://dev.to/rvinicius396g/diferenca-entre-listas-tuplas-e-dicionarios-no-python-490o | python, listas, tuplas, dicionário | Como muitos já devem saber, o Python é uma das linguagens que vem crescendo exponencialmente na análise de dados, assim como tem vários conceitos básicos que precisamos dominar par um melhor aproveitamento. Sendo assim, vou explicar o conceito de alguns itens que eu considero fundamentais e mostrar na prática nesse artigo.
Os exemplos apresentados foram executados no Jupyter Notebook, então, não estranhe a ausência do Print()
## **Listas**
Uma lista é uma estrutura de dados de forma sequencial na qual cada item é acessado a partir de um índice (a partir do zero), que representa sua posição inicial.. A lista é mutável, ou seja, pode ter seus valores alterados.
```
#Criando uma lista
listadomercado = [“ovos, farinha, leite, maças”]
# Imprimindo a lista
print(listadomercado)
# Imprimindo um item da lista
listadomercado[2]
#Adicionando mais informações a uma lista
listadomercado.append(‘Trigo’)
# Atualizando um item da lista
listadomercado[2] = “chocolate”
# Imprimindo lista alterada
print(listadomercado)
# Deletando um item específico da lista
del listadomercado[3]
# Imprimindo o item com a lista alterada
listadomercado
```
## **Listas de listas (Listas aninhadas)**
Listas de listas são matrizes em Python, em outras palavras possuem linhas e colunas
`# Criando uma lista de listas
listas = [[1,2,3], [10,15,14], [10.1,8.7,2.3]]
# Imprimindo a lista
print(listas)
`
```
# declaração de 2 listas
lista_s1 = [34, 32, 56]
lista_s2 = [21, 90, 51]
# Concatenando listas
lista_total = lista_s1 + lista_s2
print(lista_total)
```
## **Dicionários**
Dicionários são utilizados para representar chaves e valores {Key : Value}. Diferente das listas que são ordenadas pelo índice (que começa do 0), nos dicionários nós podemos definir as chaves e os valores, sendo assim, os dicionários são muito utilizados para projetos complexos.
```
# Isso é um dicionário
estudantes_dict = {“Mateus”:24, “Fernanda”:22, “Tamires”:26, “Cristiano”:25}
#Imprimindo dicionário
print(estudantes_dict)
#Podemos acessar o valor de um chave, da seguinte maneira
print(estudantes_dict[“Fernanda”])
#Limpando um dicionário
estudantes_dict.clear()
#Aqui é importante ressaltar, que ao limparmos o dicionário ele continua #existindo. No entanto, agora temos um dicionário estudantes_dict vazio !
#Adicionando mais itens ao dicionário
estudantes_dict[“Pedro”] = 23
#Deletando um dicionário, ao deletarmos ele deixa de existir
del estudantes_dict
#Exibindo toda as chaves de um dicionário
estudantes_dict.keys()
#Exibindo todas os valores de um dicionário
estudantes_dict.values()
#exibindo os itens de um dicionário (keys + values)
estudantes_dict.items()
#Exibindo o comprimento de um dicionário
print( len(estudantes_dict) )
#As chaves e valores podem ser iguais, mas apresentam informações diferentes. Ainda assim, não é recomendado criar dicionários com chaves e valores iguais, porque pode causar confusão para o entendimento de outros analistas, dificultar a manutenção etc.
dic1 = {“a”:”a"}
```
## **Tuplas**
São sequências de informações (strings, inteiros, listas, etc.) não mutáveis. Ou seja, depois que definidas não podem ter seus valores alterados. É indicado a sua utilização, somente para situações em que o valor nunca será alterado. (Ex: Fechamento da cotação de uma moeda, data de nascimento, etc.)
```
# Criando uma tupla
tupla1 = (“Geografia”, 23, “Elefantes”)
# Imprimindo a tupla
tupla1
# Tuplas não suportam append()
tupla1.append(“Chocolate”)
# Tuplas não suportam delete de um item específico
del tupla1[“Gatos”]
# Tuplas podem ter um único item
tupla1 = (“Chocolate”)
# Verificando o comprimento da tupla
len(tupla1)
# Tuplas não suportam atribuição de item
tupla1[1] = 21
# Deletando a tupla
del tupla1
# Tuplas não suportam atribuição de item
tupla1[3] = 21
```
Se precisarmos fazer alteração de uma informação na tupla, o que fazemos ?
Podemos converter para uma lista, fazemos as alterações necessárias, por fim, convertemos novamente para tupla.
```
# Convertemos tupla1 para lista
a= list(tupla1)
a.append(“test3”)
# Depois, convertemos a lista para tupla fazendo atribuição
tupla1 = tuple(a)
```
| rvinicius396g |
1,897,146 | Code Checkpoint: Memoisation and its magic | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-22T16:14:31 | https://dev.to/ahad23/code-checkpoint-memoisation-and-its-magic-13me | devchallenge, cschallenge, computerscience, beginners | *This is a submission for [DEV Computer Science Challenge v24.06.12: One Byte Explainer](https://dev.to/challenges/cs).*
## Explainer
Memoization stores the results of expensive operations and returns them quickly when needed, saving time and effort. Think of a video game save point! Instead of replaying the same level every time you lose, you save your progress. Don't hate your cache!
Also huge shoutout to my team member @vedangit !!
| ahad23 |
1,897,096 | PHP: yes, it's possible | Let's see if that's possible, then we'll see when to use it. Is is possible? Can... | 9,995 | 2024-06-22T16:11:43 | https://dev.to/spo0q/php-yes-its-possible-ao7 | php, beginners, programming | Let's see if that's possible, then we'll see when to use it.
## Is is possible?
### Can enumerations implement interfaces?
Yes.
[Source: enumeration PHP](https://www.php.net/manual/en/language.types.enumerations.php)
### Is it possible to "Multi catch" in PHP?
Yes.
Instead of doing that:
```PHP
try {
} catch(MyException $e) {
} catch(AnotherException $e) {
}
```
Do that:
```PHP
try {
} catch(MyException | AnotherException $e) {
}
```
[Source: PHP - exceptions](https://www.php.net/manual/en/language.exceptions.php)
### Can an interface extend another interface?
Yes.
Unlike with classes, you can even have multiple inheritance:
```php
interface A
{
public function foo();
}
interface B
{
public function bar();
}
interface C extends A, B
{
public function baz();
}
```
[Source: object interfaces](https://www.php.net/manual/en/language.oop5.interfaces.php)
## Do you need it?
### Does your enum need an interface?
It's usually a good practice, as you can type check for that interface quite conveniently:
```PHP
interface Colorful {
public function color(): string;
}
enum Suit implements Colorful {
case Hearts;
case Diamonds;
case Clubs;
case Spades;
public function color(): string {
return match($this) {
Suit::Hearts, Suit::Diamonds => 'Red',
Suit::Clubs, Suit::Spades => 'Black',
};
}
}
function paint(Colorful $c) { ... }
paint(Suit::Clubs);
```
[Source: RFC - enumerations](https://wiki.php.net/rfc/enumerations)
### Do you need Multi catch blocks?
It depends.
This syntax works:
```PHP
try {
} catch(MyException | AnotherException $e) {
echo $e->getMessage();
}
```
However, ensure your exceptions implement the same methods.
In contrast, using several catch blocks can be handy to catch different classes of exceptions.
Although, if you need to group your exceptions, avoid the following:
```PHP
try {
} catch(AnException | AnotherException2 | AnotherException3 | AnotherException4 | AnotherException5 | AnotherException6 | AnotherException7 | AnotherException8 | AnotherException9 $e) {
echo $e->getMessage();
}
```
While it's valid, it can give the false impression of clean code. Having too much exceptions is not a good [de]sign.
### Inheritance with interfaces
I must admit I rarely use that one, but it's good to know:
```PHP
interface Writable
{
public function write();
}
interface Document extends Writable
{
public function edit();
}
```
Do you need it?
It depends. If your interface contains too much methods, it probably means you are breaking the Interface Segregation Principle. | spo0q |
1,897,145 | Computer Science under 125 characters. | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-22T16:10:30 | https://dev.to/ahad23/computer-science-under-125-characters-52fd | devchallenge, cschallenge, computerscience, beginners | *This is a submission for [DEV Computer Science Challenge v24.06.12: One Byte Explainer](https://dev.to/challenges/cs).*
## Explainer
Assigning multiple complex tasks to metals, plastics,0's,1's, and electricity because we were too lazy to do it on pen and paper.
## Additional Context
We saw the gap of no one explaining the title of the challenge and ended up doing something raw.
## Team Submissions:
Also a huge shoutout to my team member @vedangit !!
| ahad23 |
1,897,139 | Documenting a Spring REST API Using Smart-doc | If you are developing a RESTful API with Spring Boot, you want to make it as easy as possible for... | 0 | 2024-06-22T16:10:19 | https://dev.to/yu_sun_0a160dea497156d354/documenting-a-spring-rest-api-using-smart-doc-46ic | springboot, restapi, java | If you are developing a RESTful API with Spring Boot, you want to make it as easy as possible for other developers to understand and use your API. Documentation is essential because it provides a reference for future updates and helps other developers integrate with your API. For a long time, the way to document REST APIs was to use Swagger, an open-source software framework that enables developers to design, build, document, and consume RESTful Web services. In 2018, to address the issues of code invasiveness and dependency associated with traditional API documentation tools like Swagger, we developed `smart-doc` and open-sourced it to the community.
In this article, we will explore how to use `Smart-doc` to generate documentation for a Spring Boot REST API.
## What is Smart-doc?
`Smart-doc` is an interface documentation generation tool for Java projects. It primarily analyzes and extracts comments from Java source code to produce API documentation. Smart-doc scans standard Java comments in the code, eliminating the need for specialized annotations like those used in Swagger, thus maintaining the simplicity and non-invasiveness of the code. It supports multiple formats for document output, including `Markdown`, `HTML5`, `Postman Collection`, `OpenAPI 3.0`, etc. This flexibility allows developers to choose the appropriate documentation format based on their needs. Additionally, Smart-doc can scan code to generate JMeter performance testing scripts.
For more features, please refer to the [official documentation](https://smart-doc-group.github.io/#/README)
## Steps to use Smart-doc for documenting APIs
**Step 1: Maven Project**
- Create a Maven project with the latest version of Spring Boot
- Add the Web dependencies to the project
**Step 2: Add Smart-doc Into the Project**
- Add `smart-doc-maven-plugin` to the project's `pom.xml`
```xml
<plugin>
<groupId>com.ly.smart-doc</groupId>
<artifactId>smart-doc-maven-plugin</artifactId>
<version>[latest version]</version>
<configuration>
<configFile>./src/main/resources/smart-doc.json</configFile>
<projectName>${project.description}</projectName>
</configuration>
</plugin>
```
- Create the `smart-doc.json` file in the resources directory of the module where the project startup class is located.
```json
{
"outPath": "/path/to/userdir"
}
```
**Step 3: Create a Rest Controller**
Now let's create a controller class that will handle HTTP requests and return responses.
- Create a controller class that will be sent as a JSON response.
```java
public class User {
/**
* user id
*
*/
private long id;
/**
* first name
*/
private String firstName;
/**
* last name
*/
private String lastName;
/**
* email address
*/
private String email;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
```
- Now create a service class
```java
@Repository
public class UserRepository {
private static final Map<Long, User> users = new ConcurrentHashMap<>();
static {
User user = new User();
user.setId(1);
user.setEmail("123@gmail.com");
user.setFirstName("Tom");
user.setLastName("King");
users.put(1L,user);
}
public Optional<User> findById(long id) {
return Optional.ofNullable(users.get(id));
}
public void add(User book) {
users.put(book.getId(), book);
}
public List<User> getUsers() {
return users.values().stream().collect(Collectors.toList());
}
public boolean delete(User user) {
return users.remove(user.getId(),user);
}
}
```
- Create the RestController Class.
```java
/**
* The type User controller.
*
* @author yu 2020/12/27.
*/
@RestController
@RequestMapping("/api/v1")
public class UserController {
@Resource
private UserRepository userRepository;
/**
* Create user.
*
* @param user the user
* @return the user
*/
@PostMapping("/users")
public ResponseResult<User> createUser(@Valid @RequestBody User user) {
userRepository.add(user);
return ResponseResult.ok(user);
}
/**
* Get all users list.
*
* @return the list
*/
@GetMapping("/users")
public ResponseResult<List<User>> getAllUsers() {
return ResponseResult.ok().setResultData(userRepository.getUsers());
}
/**
* Gets users by id.
*
* @param userId the user id|1
* @return the users by id
*/
@GetMapping("/users/{id}")
public ResponseResult<User> getUsersById(@PathVariable(value = "id") Long userId) {
User user = userRepository.findById(userId).
orElseThrow(() -> new ResourceNotFoundException("User not found on :: " + userId));
return ResponseResult.ok().setResultData(user);
}
/**
* Update user response entity.
*
* @param userId the user id|1
* @param userDetails the user details
* @return the response entity
*/
@PutMapping("/users/{id}")
public ResponseResult<User> updateUser(@PathVariable(value = "id") Long userId, @Valid @RequestBody User userDetails) {
User user = userRepository.findById(userId).
orElseThrow(() -> new ResourceNotFoundException("User not found on :: " + userId));
user.setEmail(userDetails.getEmail());
user.setLastName(userDetails.getLastName());
user.setFirstName(userDetails.getFirstName());
userRepository.add(user);
return ResponseResult.ok().setResultData(user);
}
/**
* Delete user.
*
* @param userId the user id|1
* @return the map
*/
@DeleteMapping("/user/{id}")
public ResponseResult<Boolean> deleteUser(@PathVariable(value = "id") Long userId) {
User user = userRepository.findById(userId).
orElseThrow(() -> new ResourceNotFoundException("User not found on :: " + userId));
return ResponseResult.ok().setResultData(userRepository.delete(user));
}
}
```
**Step 4: Generate document**
You can use the Smart-doc plugin in `IntelliJ IDEA` to generate the desired documentation, such as `OpenAPI`, `Markdown`, etc.
Of course, you can also use the Maven command to generate:
```shell
mvn smart-doc:html
// Generate document output to Markdown
mvn smart-doc:markdown
// Generate document output to Adoc
mvn smart-doc:adoc
// Generate Postman.
mvn smart-doc:postman
// Generate OpenAPI 3.0+
mvn smart-doc:openapi
```
**Step 4: Import to Postman**
Here we use `Smart-doc` to generate a `Postman.json`, then import it into `Postman` to see the effect.
Since smart-doc supports generating documentation in multiple formats, you can choose to generate `OpenAPI` and then display it using `Swagger UI` or import it into some professional API documentation systems.
## Conclusion
From the previous examples, it can be seen that Smart-doc generates documentation by **scanning standard Java comments in the code**, without the need for specialized annotations like Swagger, thus maintaining the simplicity and non-invasiveness of the code, and also not affecting the size of the service Jar package. It supports multiple formats for document output, including `Markdown`, `HTML5`, `Postman Collection`,` OpenAPI 3.0`, etc. This flexibility allows developers to choose the appropriate document format for output based on their needs. The `Maven` or `Gradle` plugins provided by smart-doc also facilitate users in integrating document generation in `Devops pipelines`.
Currently, Swagger also has its advantages, such as more powerful UI features, and better support for Springboot Webflux.
| yu_sun_0a160dea497156d354 |
1,897,143 | Dashboard Estratégico X Dashboard Operacional | Nesse pequeno artigo vou tentar trazer de forma bem resumida as principais características de um... | 0 | 2024-06-22T16:08:48 | https://dev.to/rvinicius396g/dashboard-estrategico-x-dashboard-operacional-28lh | dashboard, estratgico, operacional, bi | Nesse pequeno artigo vou tentar trazer de forma bem resumida as principais características de um Dashboard Estratégico e um Dashboard Operacional.
## Dashboards operacionais
Tem como finalidade dar uma visão em tempo real (real time) do desempenho de determinada operação, apresenta métricas bem definidas que garantem a tomada de decisão mais adequada para o momento. Sendo assim, é normal termos um número grande de informações, como por exemplo:
- Painéis com informações real-time sobre ligações recebidas/realizadas;
- Monitoramento de ligações atendidas/perdidas de um call center;
- Chamados acumulados para determinada área;
- Google Analystics com informações de trafego de um site;
## Dashboard Estratégicos
Tem como principal característica apresentar informações de uma forma simples e rápida, para que os tomadores de decisão possam acompanhar o seu negócio;
Para Few (2006, p. 41), “O uso primários de Dashboards nos dias de hoje é para propósitos estratégicos (…), [pois eles] oferecem uma rápida visão que os tomadores de decisão precisam para monitorar a saúde e as oportunidades de um negócio (…)”.
| rvinicius396g |
1,897,142 | Unlocking Twitter's Advanced Search: A Guide to Finding What Matters | Unlocking Twitter's Advanced Search: A Guide to Finding What Matters Twitter isn't just a place to... | 0 | 2024-06-22T16:07:29 | https://dev.to/learn_with_santosh/unlocking-twitters-advanced-search-a-guide-to-finding-what-matters-13a8 | twitter, tips | **Unlocking Twitter's Advanced Search: A Guide to Finding What Matters**
Twitter isn't just a place to share thoughts; it's a vast treasure trove of real-time information waiting to be explored. Whether you're a casual user or a savvy professional, mastering Twitter's advanced search capabilities can significantly enhance your experience and knowledge. Here’s how you can harness its power effectively:
### Why Use Advanced Search?
Twitter's basic search bar is great for finding recent tweets on popular topics, but advanced search takes it a step further. It allows you to pinpoint specific conversations, discover trending hashtags, follow discussions from particular users, and filter by location or sentiment. It's like having a finely tuned radar for what’s happening right now, tailored to your interests.
### How to Use Advanced Search Formulas
1. **Basic Keyword Search**: Start by typing keywords related to your interest or query into the search bar. This retrieves tweets containing those exact words or phrases.
2. **Exact Phrase Search**: Use quotation marks around phrases like "artificial intelligence" to find tweets where the words appear exactly as typed.
3. **OR Operator**: Combine related terms with OR (uppercase) to broaden your search. For example, searching for AI OR machine learning will fetch tweets containing either term.
4. **Exclude Terms**: Use a minus sign (-) before a word to exclude tweets containing that word. For instance, if you search for programming -java, you'll see tweets about programming except those mentioning Java.
5. **Hashtags**: Explore trending topics or follow specific themes by searching for hashtags like #DigitalMarketing or #MachineLearning.
6. **From a Specific User**: Type from:username to see tweets exclusively from a particular user. For example, from:NASA will show tweets from NASA's official account.
7. **To a Specific User**: Use to:username to see tweets directed at a specific user. For instance, to:elonmusk shows tweets directed to Elon Musk.
8. **Mentioning a Specific User**: Use @username to find tweets mentioning a specific user. For example, @SpaceX will show tweets referencing SpaceX.
9. **Retweets**: Include retweets in your search results with include:retweets. This helps you find popular tweets on a particular topic.
10. **Near Operator**: Find tweets from a specific location using near:city or near:"latitude,longitude,distance". For example, near:New York shows tweets from New York City.
11. **Date Range**: Narrow down results within a specific timeframe using since:yyyy-mm-dd and until:yyyy-mm-dd. This is useful for tracking developments over time.
12. **Question Search**: Add a question mark (?) to find tweets that are questions. For example, "future of AI ?" will show tweets where users are asking about the future of AI.
13. **Language Filter**: Use lang:xx to filter tweets by language. For example, crypto lang:en shows tweets about cryptocurrency in English.
14. **Sentiment Analysis**: Use :) for positive or :( for negative sentiment. For example, "quantum computing :)" will show tweets with positive sentiment about quantum computing.
### Putting It Into Practice
Imagine you’re researching AI advancements. You can use advanced search to filter tweets from experts, find recent discussions, and track emerging trends. Or, if you're a marketer, you can monitor hashtags related to your campaign to gauge audience engagement.
### Conclusion
Mastering Twitter’s advanced search isn't just about finding tweets—it's about tapping into a wealth of real-time insights and engaging with conversations that matter to you. By using these simple yet powerful search formulas, you can navigate Twitter more effectively and stay informed about the topics and trends that interest you most.
Explore today and unlock the full potential of Twitter's advanced search—it's your gateway to a world of knowledge, right at your fingertips! | learn_with_santosh |
1,897,141 | Best time to buy sell 1 | Here we address the original best stock buy-sell question. Given an array of stock prices on... | 0 | 2024-06-22T16:06:38 | https://dev.to/johnscode/best-time-to-buy-sell-1-4590 | go, interview, programming, career | Here we address the original best stock buy-sell question.
Given an array of stock prices on different days, find the maximum profit when only one buy and one sell is allowed.
This is pretty straightforward and an online search provides a number of examples.
```
func FindSingleBestBuySell(prices []float64) float64 {
buy := prices[0]
maxProfit := 0.0
for i := 0; i < len(prices); i++ {
if buy > prices[i] {
buy = prices[i]
} else if prices[i]- buy > maxProfit {
maxProfit = prices[i] - buy
}
}
return maxProfit
}
```
The solution is to maintain a buy price and a profit. Start by assuming a buy at the initial price, then step through the array. If you find a lower price, then that becomes the new buy price. Otherwise we can check potential profit; so if the potential profit is greater than that seen previously, we can sell at the current price.
Are there any gotchas here? Post your thoughts in the comments.
Thanks!
_The code for this post and all posts in this series can be found [here](https://github.com/johnscode/gocodingchallenges)_ | johnscode |
1,897,140 | Welcome to My Dev Blog: A Journey of Learning and Growth | Hey fellow devs! I'm thrilled to introduce my dev blog, a space where I'll share my experiences,... | 0 | 2024-06-22T16:05:32 | https://dev.to/vuyokazimkane/welcome-to-my-dev-blog-a-journey-of-learning-and-growth-4ca2 | Hey fellow devs! I'm thrilled to introduce my dev blog, a space where I'll share my experiences, knowledge, and passions with the developer community. As a full-stack developer with a zeal for learning and growth, I'm excited to embark on this journey with all of you.
Why I'm Starting This Blog
As a developer, I've often found myself stuck on a problem or wondering how others approach certain challenges. I believe that sharing our experiences and knowledge is essential to growing as a community. This blog is my attempt to contribute to that growth, and I hope it will become a valuable resource for fellow devs.
What to Expect
In this blog, I'll be sharing a mix of technical tutorials, personal anecdotes, and industry insights. I'll cover topics ranging from coding best practices to my favorite tools and resources. I'll also share my experiences with different programming languages, frameworks, and technologies.
My Goals
My primary goal is to create a community-driven blog where devs can come together to learn from each other, share their experiences, and get feedback on their projects. I want this blog to be a go-to resource for developers looking for inspiration, guidance, or just a fresh perspective.
How You Can Get Involved
I encourage you to participate in the conversation by commenting on my posts, sharing your own experiences, and suggesting topics you'd like me to cover. Let's build a community that supports and learns from each other.
Stay Tuned
In my upcoming posts, I'll be covering topics such as effective coding practices, my favorite development tools, and how to stay motivated as a developer. I'll also be sharing some of my personal projects and experiences, so be sure to subscribe to stay updated.
Thanks for joining me on this journey, and I look forward to hearing from you in the comments! | vuyokazimkane | |
1,897,137 | AVIF vs JPG: A Comparative Analysis | What Are the Differences Between AVIF and JPG? AVIF (AV1 Image File Format) and JPG (or... | 0 | 2024-06-22T15:58:54 | https://dev.to/msmith99994/avif-vs-jpg-a-comparative-analysis-372j | ## What Are the Differences Between AVIF and JPG?
AVIF (AV1 Image File Format) and JPG (or JPEG - Joint Photographic Experts Group) are two image formats that serve different purposes and come with their own set of characteristics. Understanding these differences can help you choose the right format for your specific needs.
### AVIF
**- Compression:** AVIF uses both lossy and lossless compression based on the AV1 video codec, which offers superior compression efficiency. This results in significantly smaller file sizes compared to other formats like JPEG.
**- Color Depth:** Supports high dynamic range (HDR) and 8-bit, 10-bit, and 12-bit color depths, which can display a wide range of colors and brightness levels.
**- Transparency:** Supports alpha channels, allowing for full transparency.
**- File Size:** Generally smaller due to highly efficient compression.
**- Quality:** Provides high image quality even at smaller file sizes.
### JPG
**- Compression:** JPG uses lossy compression, which reduces file size by discarding some image data. This can result in a loss of quality, especially at higher compression levels.
**- Color Depth:** Supports 24-bit color, displaying millions of colors, making it ideal for photographs and detailed images.
**- Transparency:** Does not support transparency.
**- File Size:** Generally larger compared to AVIF for the same image quality.
**- Quality:** Quality decreases with higher compression levels and repeated saving.
## Where Are They Used?
### AVIF
**- Web Graphics:** Ideal for high-quality images with smaller file sizes, enhancing website loading speeds and performance.
**- Photography:** Used for storing high-resolution images with minimal loss in quality.
**- Mobile Applications:** Helps in optimizing storage and performance in mobile apps by reducing image file sizes.
**- E-commerce:** Employed to showcase product images with high quality and fast loading times.
### JPG
**- Digital Photography:** Standard format for digital cameras and smartphones due to its balance of quality and file size.
**- Web Design:** Widely used for photographs and complex images on websites because of its quick loading times.
**- Social Media:** Preferred for sharing images on social platforms due to its universal support and small file size.
**- Email and Document Sharing:** Frequently used in emails and documents for easy viewing and sharing.
## Benefits and Drawbacks
### AVIF
**Benefits:**
**- Superior Compression:** Provides significantly smaller file sizes compared to other formats without sacrificing quality.
**- High Quality:** Supports HDR and higher bit depths, offering excellent image quality.
**- Transparency:** Includes support for alpha channels, allowing for transparency.
**- Performance Optimization:** Ideal for web use, enhancing loading speeds and overall performance.
**Drawbacks:**
**- Limited Compatibility:** Not as widely supported as older formats like PNG and JPEG.
**- Processing Power:** Requires more processing power for encoding and decoding compared to simpler formats.
**- Adoption:** Being a newer format, it is still gaining traction and widespread use.
### JPG
**Benefits:**
**- Small File Size:** Effective lossy compression reduces file sizes significantly.
**- Wide Compatibility:** Supported by almost all devices, browsers, and software.
**- High Color Depth:** Capable of displaying millions of colors, ideal for photographs.
**- Adjustable Quality:** Compression levels can be adjusted to balance quality and file size.
**Drawbacks:**
**- Lossy Compression:** Quality degrades with higher compression levels and repeated edits.
**- No Transparency:** Does not support transparent backgrounds.
**- Limited Editing Capability:** Cumulative compression losses make it less ideal for extensive editing.
## When You Should Use Each One
**Use AVIF When:**
- You need high-quality images with small file sizes to optimize web performance.
- You want to take advantage of high dynamic range (HDR) and higher bit depths.
- You require images with transparency support for complex web graphics.
- Your target audience uses modern browsers and devices that support AVIF.
**Use JPG When:**
- You need a widely compatible format that works across almost all devices and platforms.
- You are working with digital photography and need a good balance of quality and file size.
- You need to share images on social media or through email, where universal support is essential.
- You are dealing with simpler images that do not require transparency or high dynamic range.
## Final Thoughts
[AVIF and JPG](https://cloudinary.com/tools/avif-to-jpg) are both essential image formats with distinct advantages and use cases. AVIF excels in providing high-quality images with superior compression efficiency, making it ideal for modern web applications and high-resolution photography. JPG remains a staple for digital photography, web design, and social media due to its wide compatibility and balance of quality and file size.
Understanding the differences between AVIF and JPG, and knowing when to use each format, allows you to optimize your images for the best performance and quality. Whether you need the advanced capabilities of AVIF or the broad compatibility of JPG, mastering these formats ensures you can handle any digital image requirement effectively. | msmith99994 | |
1,897,130 | nav-bar | Check out this Pen I made! | 0 | 2024-06-22T15:36:55 | https://dev.to/myvoice/nav-bar-5ae0 | codepen, css, html, webdev | Check out this Pen I made!
{% codepen https://codepen.io/myvoice/pen/ExJzgVb %} | myvoice |
1,897,113 | Solution for Render.com Web services spin down due to inactivity. | When deploying backend applications for hobby projects, Render is a popular choice due to its... | 0 | 2024-06-22T15:51:11 | https://dev.to/harshgit98/solution-for-rendercom-web-services-spin-down-due-to-inactivity-2h8i | render, deployment, node, tutorial | When deploying backend applications for hobby projects, Render is a popular choice due to its simplicity and feature set. However, one common issue with Render is that instances can spin down due to inactivity. This results in delayed responses of up to a minute when the instance has to be redeployed. This behavior is clearly mentioned by Render:
**The Problem**
Render instances spin down when inactive, leading to delays when the server is accessed after a period of inactivity. This can be particularly annoying as it affects the user experience with slow response times.
**The Solution**
To keep your instance active even when no one is using the site, you can add a self-referencing reloader in your app.js or index.js file. This will periodically ping your server, preventing it from spinning down.
Here’s a simple snippet of code to achieve this:
```
const url = `https://yourappname.onrender.com/`; // Replace with your Render URL
const interval = 30000; // Interval in milliseconds (30 seconds)
//Reloader Function
function reloadWebsite() {
axios.get(url)
.then(response => {
console.log(`Reloaded at ${new Date().toISOString()}: Status Code ${response.status}`);
})
.catch(error => {
console.error(`Error reloading at ${new Date().toISOString()}:`, error.message);
});
}
setInterval(reloadWebsite, interval);
```
**How It Works**
- Self-Referencing Reload: This code snippet sets an interval to ping your server every 30 seconds.
- Keep Alive: By continuously pinging the server, it remains active, preventing it from spinning down.
- Logs: You can monitor the logs to see the periodic checks and ensure the server is active.
**Implementation**
1. Add the Code: Insert the above code into your app.js or index.js file.
2. Start Your Server: Deploy your application to Render as usual.
3. Monitor: Check the logs in your Render dashboard to verify that the server is being pinged regularly.
**Benefits**
1. No Downtime: Your server remains active, providing quick responses.
2. Simple Solution: Easy to implement without complex configurations.
3. Scalability: Works well for small to medium-level hobby projects.
**Managing Multiple Backends**
For projects with multiple backends, you can consolidate the reloaders into a single backend. This approach ensures all instances remain active without each backend needing its own reloader.
**Conclusion**
By adding a simple reloader script to your backend, you can prevent Render instances from spinning down due to inactivity. This ensures that your server remains responsive, providing a better user experience for your hobby projects. This solution is effective for small to medium-level projects and helps maintain constant activity on your server.
[Github](https://github.com/Harsh-git98/render.com-spindown-solution)
Hope this helps! Happy Deployment.
| harshgit98 |
1,897,135 | Feedback : Using embedded python daily for more than 2 years | I have been using embedded python for more than 2 years now on a daily basis. May be it's time to... | 0 | 2024-06-22T15:44:14 | https://community.intersystems.com/post/feedback-using-embedded-python-daily-more-2-years | beginners, python, framework, languages | I have been using embedded python for more than 2 years now on a daily basis.
May be it's time to share some feedback about this journey.
Why write this feedback? Because, I guess, I'm like most of the people here, an ObjectScript developer, and I think that the community would benefit from this feedback and could better understand the pros & cons of chosing embedded python for developing stuff in IRIS. And also avoid some pitfalls.
* [Feedback : Using embedded python daily for 2 years](#feedback--using-embedded-python-daily-for-2-years)
* [Introduction](#introduction)
* [Starting with Python](#starting-with-python)
* [Python is not ObjectScript](#python-is-not-objectscript)
* [Pep8](#pep8)
* [Modules](#modules)
* [Dunders](#dunders)
* [Conclusion](#conclusion)
* [Embedded Python](#embedded-python)
* [What is Embedded Python ?](#what-is-embedded-python-)
* [How to use Embedded Python ?](#how-to-use-embedded-python-)
* [How I use Embedded Python](#how-i-use-embedded-python)
* [Use Python libraries and code as they were ObjectScript classes](#use-python-libraries-and-code-as-they-were-objectscript-classes)
* [With the language tag](#with-the-language-tag)
* [Without the language tag](#without-the-language-tag)
* [Conclusion](#conclusion-1)
* [Use a python first approach](#use-a-python-first-approach)
* [Example : iris-fhir-python-strategy](#example--iris-fhir-python-strategy)
* [Remarks](#remarks)
* [Where to find the code](#where-to-find-the-code)
* [How to implement a Strategy](#how-to-implement-a-strategy)
* [Implementation of InteractionsStrategy](#implementation-of-interactionsstrategy)
* [Implementation of Interactions](#implementation-of-interactions)
* [Interactions in Python](#interactions-in-python)
* [Implementation of the abstract python class](#implementation-of-the-abstract-python-class)
* [Too long, do a summary](#too-long-do-a-summary)
<!--break-->
# Introduction
I'm a developer since 2010, and I have been working with ObjectScript since 2013.
So roughly 10 years of experience with ObjectScript.
Since 2021 and the release of Embedded Python in IRIS, I put my self a challenge :
* Learn Python
* Do as much as possible everything in Python
When I started this journey, I had no idea of what Python was. So I started with the basics, and I'm still learning every day.
# Starting with Python
The good thing with Python is that it's easy to learn. It's even easier when you already know ObjectScript.
**Why ?** They have a lot in common.
| ObjectScript | Python |
| ----------- | ------ |
| Untyped | Untyped |
| Scripting language | Scripting language |
| Object Oriented | Object Oriented |
| Interpreted | Interpreted |
| Easy C integration | Easy C integration |
</br>
**So, if you know ObjectScript, you already know a lot about Python.**
But, there are some differences, and some of them are not easy to understand.
# Python is not ObjectScript
To keep it simple, I will focus on the *main differences* between ObjectScript and Python.
For me there are mainly 3 differences :
* Pep8
* Modules
* Dunders
## Pep8
What the hell is **Pep8** ?
It's a set of rules to write Python code.
[pep8.org](https://www.python.org/dev/peps/pep-0008/)
Few of them are :
* naming convention
* variable names
* snake_case
* class names
* CamelCase
* indentation
* line length
* etc.
**Why is it important ?**
Because it's the way to write Python code. And if you don't follow these rules, you will have a hard time to read other people's code, and they will have a hard time to read your code.
As ObjectScript developers, we also have some rules to follow, but they are not as strict as Pep8.
*I learned Pep8 the hard way.*
For the story, I'm a sales engineer at InterSystems, and I'm doing a lot of demos. And one day, I was doing a demo of Embedded Python to a customer, this customer was a Python developer, and the conversation turned short when he saw my code. He told me that my code was not Pythonic at all (he was right) I was coding in python like I was coding in ObjectScript. And because of that, he told me that he was not interested in Embedded Python anymore. I was shocked, and I decided to learn Python the right way.
So, if you want to learn Python, learn Pep8 first.
## Modules
*Modules are something that we don't have in ObjectScript.*
Usually, in object oriented languages, you have classes, and packages. In Python, you have classes, packages, and modules.
**What is a module ?**
It's a file with a .py extension. And it's the way to organize your code.
You didn't understand ? Me neither at the beginning. So let's take an example.
Usually, when you want to create a class in ObjectScript, you create a .cls file, and you put your class in it. And if you want to create another class, you create another .cls file. And if you want to create a package, you create a folder, and you put your .cls files in it.
In Python, it's the same, but Python bring the ability to have multiple classes in a single file. And this file is called a module.
FYI, It's `Pythonic` to have multiple classes in a single file.
**So plan head how you will organize your code**, and how you will name your modules to **not end up like me with a lot of modules with the same name as your classes**.
*A bad example* :
MyClass.py
```python
class MyClass:
def __init__(self):
pass
def my_method(self):
pass
```
To instantiate this class, you will do :
```python
import MyClass.MyClass # weird right ?
my_class = MyClass()
```
**Weird right ?**
## Dunders
**Dunders are special methods in Python.** They are called dunder because they start and end with *double underscores*.
They are kind of our `%` methods in ObjectScript.
They are used for :
* constructor
* operator overloading
* object representation
* etc.
Example :
```python
class MyClass:
def __init__(self):
pass
def __repr__(self):
return "MyClass"
def __add__(self, other):
return self + other
```
Here we have 3 dunder methods :
* `__init__` : constructor
* `__repr__` : object representation
* `__add__` : operator overloading
**Dunders methods are everywhere in Python**. It's a major part of the language, but don't worry, you will learn them quickly.
## Conclusion
**Python is not ObjectScript**, and you will have to learn it. But it's not that hard, and you will learn it quickly.
Just keep in mind that you will have to learn Pep8, and how to organize your code with modules and dunder methods.
*Good sites to learn Python :*
* [geeksforgeeks.org](https://www.geeksforgeeks.org/python-programming-language/)
* [w3schools.com](https://www.w3schools.com/python/)
* [realpython.com](https://realpython.com/)
---------
# Embedded Python
Now that you know a little bit more about Python, let's talk about Embedded Python.
## What is Embedded Python ?
**Embedded Python** is a way to execute Python code in IRIS. It's a new feature of **IRIS 2021.2+**.
This means that your python code will be executed in the same process as IRIS.
For the more, every ObjectScript class is a Python class, same for methods and attributes and vice versa. 🥳
This is neat !
## How to use Embedded Python ?
There are 3 main ways to use Embedded Python :
* Using the language tag in ObjectScript
* Method Foo() As %String [ Language = python ]
* Using the ##class(%SYS.Python).Import() function
* Using the python interpreter
* python3 -c "import iris; print(iris.system.Version.GetVersion())"
But if you want to be serious about Embedded Python, you will have to **avoid using the language tag**.
Why ?
* Because it's not Pythonic
* Because it's not ObjectScript either
* Because you don't have a debugger
* Because you don't have a linter
* Because you don't have a formatter
* Because you don't have a test framework
* Because you don't have a package manager
* Because you are mixing 2 languages in the same file
* Because when you process crashes, you don't have a stack trace
* Because you can't use virtual environments or conda environments
* ...
Don't get me wrong, it works, it can be useful, if you want to test something quickly, but IMO it's not a good practice.
So, what did I learn from this 2 years of Embedded Python, and how to use it the right way ?
# How I use Embedded Python
For me, you have two options :
* Use Python libraries as they were ObjectScript classes
* with ##class(%SYS.Python).Import() function
* Use a python first approach
## Use Python libraries and code as they were ObjectScript classes
You still want to use Python in your ObjectScript code, but you don't want to use the language tag. So what can you do ?
"Simply" use Python libraries and code as they were ObjectScript classes.
Let's take an example :
You want to use the `requests` library ( it's a library to make HTTP requests ) in your ObjectScript code.
## With the language tag
```objectscript
ClassMethod Get() As %Status [ Language = python ]
{
import requests
url = "https://httpbin.org/get"
# make a get request
response = requests.get(url)
# get the json data from the response
data = response.json()
# iterate over the data and print key-value pairs
for key, value in data.items():
print(key, ":", value)
}
```
**Why I think it's not a good idea ?**
Because you are mixing 2 languages in the same file, and you don't have a debugger, a linter, a formatter, etc.
If this code crashes, you will have a hard time to debug it.
You don't have a stack trace, and you don't know where the error comes from.
And you don't have auto-completion.
## Without the language tag
```objectscript
ClassMethod Get() As %Status
{
set status = $$$OK
set url = "https://httpbin.org/get"
// Import Python module "requests" as an ObjectScript class
set request = ##class(%SYS.Python).Import("requests")
// Call the get method of the request class
set response = request.get(url)
// Call the json method of the response class
set data = response.json()
// Here data is a Python dictionary
// To iterate over a Python dictionary, you have to use the dunder method and items()
// Import built-in Python module
set builtins = ##class(%SYS.Python).Import("builtins")
// Here we are using len from the builtins module to get the length of the dictionary
For i = 0:1:builtins.len(data)-1 {
// Now we convert the items of the dictionary to a list, and we get the key and the value using the dunder method __getitem__
Write builtins.list(data.items())."__getitem__"(i)."__getitem__"(0),": ",builtins.list(data.items())."__getitem__"(i)."__getitem__"(1),!
}
quit status
}
```
**Why I think it's a good idea ?**
Because you are using Python as it was ObjectScript. You are importing the `requests` library as an ObjectScript class, and you are using it as an ObjectScript class.
All the logic is in ObjectScript, and you are using Python as a library.
Even for maintenance, it's easier to read and understand, any ObjectScript developer can understand this code.
The drawback is that you have to know how to use duners methods, and how to use Python as it was ObjectScript.
## Conclusion
Belive me, this way you will end up with a more robust code, and you will be able to debug it easily.
At first, it's seems hard, but you will find the benefits of learning Python faster than you think.
# Use a python first approach
This is the way I prefer to use Embedded Python.
I have built a lot of tools using this approach, and I'm very happy with it.
Few examples :
* [iop](https://github.com/grongierisc/interoperability-embedded-python)
* [iris-python-interoperability-template](https://github.com/grongierisc/iris-python-interoperability-template)
* [iris-imap-adapter](https://github.com/grongierisc/iris-imap-python-adaptor)
* [iris-chemicals-properties](https://github.com/grongierisc/iris-chemicals-properties)
* [rest-to-dicom](https://github.com/grongierisc/RestToDicom)
* [iris-fhir-python-strategy](https://github.com/grongierisc/iris-fhir-python-strategy)
*So, what is a python first approach ?*
There is only one rule : **Python code must be in .py files, ObjectScript code must be in .cls files**
*How to achieve this ?*
**The whole idea is to create ObjectScript wrappers classes to call Python code.**
---------
Let's take the example of `iris-fhir-python-strategy` :
# Example : iris-fhir-python-strategy
First of all, we have to understand how IRIS FHIR Server works.
Every IRIS FHIR Server implements a `Strategy`.
A `Strategy` is a set of two classes :
| Superclass | Subclass Parameters |
| ---------- | ------------------- |
| HS.FHIRServer.API.InteractionsStrategy | `StrategyKey` — Specifies a unique identifier for the InteractionsStrategy.<br> `InteractionsClass` — Specifies the name of your Interactions subclass.|
| HS.FHIRServer.API.RepoManager | `StrategyClass` — Specifies the name of your InteractionsStrategy subclass.<br> `StrategyKey` — Specifies a unique identifier for the InteractionsStrategy. Must match the StrategyKey parameter in the InteractionsStrategy subclass.|
Both classes are `Abstract` classes.
* `HS.FHIRServer.API.InteractionsStrategy` is an `Abstract` class that must be implemented to customize the behavior of the FHIR Server.
* `HS.FHIRServer.API.RepoManager` is an `Abstract` class that must be implemented to customize the storage of the FHIR Server.
## Remarks
For our example, we will only focus on the `HS.FHIRServer.API.InteractionsStrategy` class even if the `HS.FHIRServer.API.RepoManager` class is also implemented and mandatory to customize the FHIR Server.
The `HS.FHIRServer.API.RepoManager` class is implemented by `HS.FHIRServer.Storage.Json.RepoManager` class, which is the default implementation of the FHIR Server.
## Where to find the code
All source code can be found in this repository : [iris-fhir-python-strategy](https://github.com/grongierisc/iris-fhir-python-strategy)
The `src` folder contains the following folders :
* `python` : contains the python code
* `cls` : contains the ObjectScript code that is used to call the python code
## How to implement a Strategy
In this proof of concept, we will only be interested in how to implement a `Strategy` in Python, not how to implement a `RepoManager`.
To implement a `Strategy` you need to create at least two classes :
* A class that inherits from `HS.FHIRServer.API.InteractionsStrategy` class
* A class that inherits from `HS.FHIRServer.API.Interactions` class
## Implementation of InteractionsStrategy
`HS.FHIRServer.API.InteractionsStrategy` class aim to customize the behavior of the FHIR Server by overriding the following methods :
* `GetMetadataResource` : called to get the metadata of the FHIR Server
* this is the only method we will override in this proof of concept
`HS.FHIRServer.API.InteractionsStrategy` has also two parameters :
* `StrategyKey` : a unique identifier for the InteractionsStrategy
* `InteractionsClass` : the name of your Interactions subclass
## Implementation of Interactions
`HS.FHIRServer.API.Interactions` class aim to customize the behavior of the FHIR Server by overriding the following methods :
* `OnBeforeRequest` : called before the request is sent to the server
* `OnAfterRequest` : called after the request is sent to the server
* `PostProcessRead` : called after the read operation is done
* `PostProcessSearch` : called after the search operation is done
* `Read` : called to read a resource
* `Add` : called to add a resource
* `Update` : called to update a resource
* `Delete` : called to delete a resource
* and many more...
We implement `HS.FHIRServer.API.Interactions` class in the `src/cls/FHIR/Python/Interactions.cls` class.
<div class="spoiler">
<div class="spoiler-title">
<div class="spoiler-toggle hide-icon"> </div>Spoiler</div>
<div class="spoiler-content">
<pre class="codeblock-container" idlang="0" lang="ObjectScript" tabsize="4"><code class="language-cls hljs cos"><span class="hljs-keyword">Class</span> FHIR.Python.Interactions <span class="hljs-keyword">Extends</span> (HS.FHIRServer.Storage.Json.Interactions, FHIR.Python.Helper)
{
<span class="hljs-keyword">Parameter</span> OAuth2TokenHandlerClass <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span> = <span class="hljs-string">"FHIR.Python.OAuth2Token"</span><span class="hljs-comment">;</span>
Method <span class="hljs-built_in">%OnNew</span>(pStrategy <span class="hljs-keyword">As</span> HS.FHIRServer.Storage.Json.InteractionsStrategy) <span class="hljs-keyword">As</span> <span class="hljs-built_in">%Status</span>
{
<span class="hljs-comment">// %OnNew is called when the object is created.</span>
<span class="hljs-comment">// The pStrategy parameter is the strategy object that created this object.</span>
<span class="hljs-comment">// The default implementation does nothing</span>
<span class="hljs-comment">// Frist set the python path from an env var</span>
<span class="hljs-keyword">set</span> <span class="hljs-built_in">..PythonPath</span> = <span class="hljs-built_in">$system</span>.Util.GetEnviron(<span class="hljs-string">"INTERACTION_PATH"</span>)
<span class="hljs-comment">// Then set the python class name from the env var</span>
<span class="hljs-keyword">set</span> <span class="hljs-built_in">..PythonClassname</span> = <span class="hljs-built_in">$system</span>.Util.GetEnviron(<span class="hljs-string">"INTERACTION_CLASS"</span>)
<span class="hljs-comment">// Then set the python module name from the env var</span>
<span class="hljs-keyword">set</span> <span class="hljs-built_in">..PythonModule</span> = <span class="hljs-built_in">$system</span>.Util.GetEnviron(<span class="hljs-string">"INTERACTION_MODULE"</span>)
<span class="hljs-keyword">if</span> (<span class="hljs-built_in">..PythonPath</span> = <span class="hljs-string">""</span>) || (<span class="hljs-built_in">..PythonClassname</span> = <span class="hljs-string">""</span>) || (<span class="hljs-built_in">..PythonModule</span> = <span class="hljs-string">""</span>) {
<span class="hljs-comment">//quit ##super(pStrategy)</span>
<span class="hljs-keyword">set</span> <span class="hljs-built_in">..PythonPath</span> = <span class="hljs-string">"/irisdev/app/src/python/"</span>
<span class="hljs-keyword">set</span> <span class="hljs-built_in">..PythonClassname</span> = <span class="hljs-string">"CustomInteraction"</span>
<span class="hljs-keyword">set</span> <span class="hljs-built_in">..PythonModule</span> = <span class="hljs-string">"custom"</span>
}
<span class="hljs-comment">// Then set the python class</span>
<span class="hljs-keyword">do</span> <span class="hljs-built_in">..SetPythonPath</span>(<span class="hljs-built_in">..PythonPath</span>)
<span class="hljs-keyword">set</span> <span class="hljs-built_in">..PythonClass</span> = <span class="hljs-keyword">##class</span>(FHIR.Python.Interactions).GetPythonInstance(<span class="hljs-built_in">..PythonModule</span>, <span class="hljs-built_in">..PythonClassname</span>)
<span class="hljs-keyword">quit</span> <span class="hljs-keyword">##super</span>(pStrategy)
}
Method OnBeforeRequest(
pFHIRService <span class="hljs-keyword">As</span> HS.FHIRServer.API.Service,
pFHIRRequest <span class="hljs-keyword">As</span> HS.FHIRServer.API.Data.Request,
pTimeout <span class="hljs-keyword">As</span> <span class="hljs-built_in">%Integer</span>)
{
<span class="hljs-comment">// OnBeforeRequest is called before each request is processed.</span>
<span class="hljs-keyword">if</span> <span class="hljs-built_in">$ISOBJECT</span>(<span class="hljs-built_in">..PythonClass</span>) {
<span class="hljs-keyword">set</span> body = <span class="hljs-keyword">##class</span>(<span class="hljs-built_in">%SYS.Python</span>).None()
<span class="hljs-keyword">if</span> pFHIRRequest.Json '= <span class="hljs-string">""</span> {
<span class="hljs-keyword">set</span> jsonLib = <span class="hljs-keyword">##class</span>(<span class="hljs-built_in">%SYS.Python</span>).Import(<span class="hljs-string">"json"</span>)
<span class="hljs-keyword">set</span> body = jsonLib.loads(pFHIRRequest.Json.<span class="hljs-built_in">%ToJSON</span>())
}
<span class="hljs-keyword">do</span> <span class="hljs-built_in">..PythonClass</span>.<span class="hljs-string">"on_before_request"</span>(pFHIRService, pFHIRRequest, body, pTimeout)
}
}
Method OnAfterRequest(
pFHIRService <span class="hljs-keyword">As</span> HS.FHIRServer.API.Service,
pFHIRRequest <span class="hljs-keyword">As</span> HS.FHIRServer.API.Data.Request,
pFHIRResponse <span class="hljs-keyword">As</span> HS.FHIRServer.API.Data.Response)
{
<span class="hljs-comment">// OnAfterRequest is called after each request is processed.</span>
<span class="hljs-keyword">if</span> <span class="hljs-built_in">$ISOBJECT</span>(<span class="hljs-built_in">..PythonClass</span>) {
<span class="hljs-keyword">set</span> body = <span class="hljs-keyword">##class</span>(<span class="hljs-built_in">%SYS.Python</span>).None()
<span class="hljs-keyword">if</span> pFHIRResponse.Json '= <span class="hljs-string">""</span> {
<span class="hljs-keyword">set</span> jsonLib = <span class="hljs-keyword">##class</span>(<span class="hljs-built_in">%SYS.Python</span>).Import(<span class="hljs-string">"json"</span>)
<span class="hljs-keyword">set</span> body = jsonLib.loads(pFHIRResponse.Json.<span class="hljs-built_in">%ToJSON</span>())
}
<span class="hljs-keyword">do</span> <span class="hljs-built_in">..PythonClass</span>.<span class="hljs-string">"on_after_request"</span>(pFHIRService, pFHIRRequest, pFHIRResponse, body)
}
}
Method PostProcessRead(pResourceObject <span class="hljs-keyword">As</span> <span class="hljs-built_in">%DynamicObject</span>) <span class="hljs-keyword">As</span> <span class="hljs-built_in">%Boolean</span>
{
<span class="hljs-comment">// PostProcessRead is called after a resource is read from the database.</span>
<span class="hljs-comment">// Return 1 to indicate that the resource should be included in the response.</span>
<span class="hljs-comment">// Return 0 to indicate that the resource should be excluded from the response.</span>
<span class="hljs-keyword">if</span> <span class="hljs-built_in">$ISOBJECT</span>(<span class="hljs-built_in">..PythonClass</span>) {
<span class="hljs-keyword">if</span> pResourceObject '= <span class="hljs-string">""</span> {
<span class="hljs-keyword">set</span> jsonLib = <span class="hljs-keyword">##class</span>(<span class="hljs-built_in">%SYS.Python</span>).Import(<span class="hljs-string">"json"</span>)
<span class="hljs-keyword">set</span> body = jsonLib.loads(pResourceObject.<span class="hljs-built_in">%ToJSON</span>())
}
<span class="hljs-keyword">return</span> <span class="hljs-built_in">..PythonClass</span>.<span class="hljs-string">"post_process_read"</span>(body)
}
<span class="hljs-keyword">quit</span> <span class="hljs-number">1</span>
}
Method PostProcessSearch(
pRS <span class="hljs-keyword">As</span> HS.FHIRServer.Util.SearchResult,
pResourceType <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>) <span class="hljs-keyword">As</span> <span class="hljs-built_in">%Status</span>
{
<span class="hljs-comment">// PostProcessSearch is called after a search is performed.</span>
<span class="hljs-comment">// Return $$$OK to indicate that the search was successful.</span>
<span class="hljs-comment">// Return an error code to indicate that the search failed.</span>
<span class="hljs-keyword">if</span> <span class="hljs-built_in">$ISOBJECT</span>(<span class="hljs-built_in">..PythonClass</span>) {
<span class="hljs-keyword">return</span> <span class="hljs-built_in">..PythonClass</span>.<span class="hljs-string">"post_process_search"</span>(pRS, pResourceType)
}
<span class="hljs-keyword">quit</span> <span class="hljs-built_in">$$$OK</span>
}
Method <span class="hljs-keyword">Read</span>(
pResourceType <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>,
pResourceId <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>,
pVersionId <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span> = <span class="hljs-string">""</span>) <span class="hljs-keyword">As</span> <span class="hljs-built_in">%DynamicObject</span>
{
<span class="hljs-keyword">return</span> <span class="hljs-keyword">##super</span>(pResourceType, pResourceId, pVersionId)
}
Method Add(
pResourceObj <span class="hljs-keyword">As</span> <span class="hljs-built_in">%DynamicObject</span>,
pResourceIdToAssign <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span> = <span class="hljs-string">""</span>,
pHttpMethod = <span class="hljs-string">"POST"</span>) <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>
{
<span class="hljs-keyword">return</span> <span class="hljs-keyword">##super</span>(pResourceObj, pResourceIdToAssign, pHttpMethod)
}
<span class="hljs-comment">/// Returns VersionId for the "deleted" version</span>
Method Delete(
pResourceType <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>,
pResourceId <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>) <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>
{
<span class="hljs-keyword">return</span> <span class="hljs-keyword">##super</span>(pResourceType, pResourceId)
}
Method Update(pResourceObj <span class="hljs-keyword">As</span> <span class="hljs-built_in">%DynamicObject</span>) <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>
{
<span class="hljs-keyword">return</span> <span class="hljs-keyword">##super</span>(pResourceObj)
}
}</code></pre>
<p> </p>
</div>
</div>
<p> </p>
The `FHIR.Python.Interactions` class inherits from `HS.FHIRServer.Storage.Json.Interactions` class and `FHIR.Python.Helper` class.
The `HS.FHIRServer.Storage.Json.Interactions` class is the default implementation of the FHIR Server.
The `FHIR.Python.Helper` class aim to help to call Python code from ObjectScript.
The `FHIR.Python.Interactions` class overrides the following methods :
* `%OnNew` : called when the object is created
* we use this method to set the python path, python class name and python module name from environment variables
* if the environment variables are not set, we use default values
* we also set the python class
* we call the `%OnNew` method of the parent class
```objectscript
Method %OnNew(pStrategy As HS.FHIRServer.Storage.Json.InteractionsStrategy) As %Status
{
// First set the python path from an env var
set ..PythonPath = $system.Util.GetEnviron("INTERACTION_PATH")
// Then set the python class name from the env var
set ..PythonClassname = $system.Util.GetEnviron("INTERACTION_CLASS")
// Then set the python module name from the env var
set ..PythonModule = $system.Util.GetEnviron("INTERACTION_MODULE")
if (..PythonPath = "") || (..PythonClassname = "") || (..PythonModule = "") {
// use default values
set ..PythonPath = "/irisdev/app/src/python/"
set ..PythonClassname = "CustomInteraction"
set ..PythonModule = "custom"
}
// Then set the python class
do ..SetPythonPath(..PythonPath)
set ..PythonClass = ..GetPythonInstance(..PythonModule, ..PythonClassname)
quit ##super(pStrategy)
}
```
* `OnBeforeRequest` : called before the request is sent to the server
* we call the `on_before_request` method of the python class
* we pass the `HS.FHIRServer.API.Service` object, the `HS.FHIRServer.API.Data.Request` object, the body of the request and the timeout
```objectscript
Method OnBeforeRequest(
pFHIRService As HS.FHIRServer.API.Service,
pFHIRRequest As HS.FHIRServer.API.Data.Request,
pTimeout As %Integer)
{
// OnBeforeRequest is called before each request is processed.
if $ISOBJECT(..PythonClass) {
set body = ##class(%SYS.Python).None()
if pFHIRRequest.Json '= "" {
set jsonLib = ##class(%SYS.Python).Import("json")
set body = jsonLib.loads(pFHIRRequest.Json.%ToJSON())
}
do ..PythonClass."on_before_request"(pFHIRService, pFHIRRequest, body, pTimeout)
}
}
```
* `OnAfterRequest` : called after the request is sent to the server
* we call the `on_after_request` method of the python class
* we pass the `HS.FHIRServer.API.Service` object, the `HS.FHIRServer.API.Data.Request` object, the `HS.FHIRServer.API.Data.Response` object and the body of the response
```objectscript
Method OnAfterRequest(
pFHIRService As HS.FHIRServer.API.Service,
pFHIRRequest As HS.FHIRServer.API.Data.Request,
pFHIRResponse As HS.FHIRServer.API.Data.Response)
{
// OnAfterRequest is called after each request is processed.
if $ISOBJECT(..PythonClass) {
set body = ##class(%SYS.Python).None()
if pFHIRResponse.Json '= "" {
set jsonLib = ##class(%SYS.Python).Import("json")
set body = jsonLib.loads(pFHIRResponse.Json.%ToJSON())
}
do ..PythonClass."on_after_request"(pFHIRService, pFHIRRequest, pFHIRResponse, body)
}
}
```
* And so on...
## Interactions in Python
`FHIR.Python.Interactions` class calls the `on_before_request`, `on_after_request`, ... methods of the python class.
Here is the abstract python class :
```python
import abc
import iris
class Interaction(object):
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def on_before_request(self,
fhir_service:'iris.HS.FHIRServer.API.Service',
fhir_request:'iris.HS.FHIRServer.API.Data.Request',
body:dict,
timeout:int):
"""
on_before_request is called before the request is sent to the server.
param fhir_service: the fhir service object iris.HS.FHIRServer.API.Service
param fhir_request: the fhir request object iris.FHIRServer.API.Data.Request
param timeout: the timeout in seconds
return: None
"""
@abc.abstractmethod
def on_after_request(self,
fhir_service:'iris.HS.FHIRServer.API.Service',
fhir_request:'iris.HS.FHIRServer.API.Data.Request',
fhir_response:'iris.HS.FHIRServer.API.Data.Response',
body:dict):
"""
on_after_request is called after the request is sent to the server.
param fhir_service: the fhir service object iris.HS.FHIRServer.API.Service
param fhir_request: the fhir request object iris.FHIRServer.API.Data.Request
param fhir_response: the fhir response object iris.FHIRServer.API.Data.Response
return: None
"""
@abc.abstractmethod
def post_process_read(self,
fhir_object:dict) -> bool:
"""
post_process_read is called after the read operation is done.
param fhir_object: the fhir object
return: True the resource should be returned to the client, False otherwise
"""
@abc.abstractmethod
def post_process_search(self,
rs:'iris.HS.FHIRServer.Util.SearchResult',
resource_type:str):
"""
post_process_search is called after the search operation is done.
param rs: the search result iris.HS.FHIRServer.Util.SearchResult
param resource_type: the resource type
return: None
"""
```
## Implementation of the abstract python class
```python
from FhirInteraction import Interaction
class CustomInteraction(Interaction):
def on_before_request(self, fhir_service, fhir_request, body, timeout):
#Extract the user and roles for this request
#so consent can be evaluated.
self.requesting_user = fhir_request.Username
self.requesting_roles = fhir_request.Roles
def on_after_request(self, fhir_service, fhir_request, fhir_response, body):
#Clear the user and roles between requests.
self.requesting_user = ""
self.requesting_roles = ""
def post_process_read(self, fhir_object):
#Evaluate consent based on the resource and user/roles.
#Returning 0 indicates this resource shouldn't be displayed - a 404 Not Found
#will be returned to the user.
return self.consent(fhir_object['resourceType'],
self.requesting_user,
self.requesting_roles)
def post_process_search(self, rs, resource_type):
#Iterate through each resource in the search set and evaluate
#consent based on the resource and user/roles.
#Each row marked as deleted and saved will be excluded from the Bundle.
rs._SetIterator(0)
while rs._Next():
if not self.consent(rs.ResourceType,
self.requesting_user,
self.requesting_roles):
#Mark the row as deleted and save it.
rs.MarkAsDeleted()
rs._SaveRow()
def consent(self, resource_type, user, roles):
#Example consent logic - only allow users with the role '%All' to see
#Observation resources.
if resource_type == 'Observation':
if '%All' in roles:
return True
else:
return False
else:
return True
```
# Too long, do a summary
The `FHIR.Python.Interactions` class is a wrapper to call the python class.
IRIS abstracts classes are implemented to wrap python abstract classes 🥳.
That help us to keep python code and ObjectScript code separated and for so benefit from the best of both worlds. | intersystemsdev |
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1,897,129 | Generating meaningful test data using Gemini | We all know that having a set of proper test data before deploying an application to production is... | 0 | 2024-06-22T15:36:49 | https://community.intersystems.com/post/generating-meaningful-test-data-using-gemini | ai, tutorial, beginners, programming | <p>We all know that having a set of proper test data before deploying an application to production is crucial for ensuring its reliability and performance. It allows to simulate real-world scenarios and identify potential issues or bugs before they impact end-users. Moreover, testing with representative data sets allows to optimize performance, identify bottlenecks, and fine-tune algorithms or processes as needed. Ultimately, having a comprehensive set of test data helps to deliver a higher quality product, reducing the likelihood of post-production issues and enhancing the overall user experience. </p>
<p>In this article, let's look at how one can use generative AI, namely <a href="https://gemini.google.com/" target="_blank">Gemini by Google</a>, to generate (hopefully) meaningful data for the properties of multiple objects. To do this, I will use the RESTful service to generate data in a JSON format and then use the received data to create objects.</p>
<p><!--break--></p>
<p>This leads to an obvious question: why not use the methods from <code>%Library.PopulateUtils</code> to generate all the data? Well, the answer is quite obvious as well if you've seen the list of methods of the class - there aren't many methods that generate meaningful data.</p>
<p>So, let's get to it.</p>
<p>Since I'll be using the Gemini API, I will need to generate the API key first since I don't have it beforehand. To do this, just open <a href="https://aistudio.google.com/app/apikey" target="_blank">aistudio.google.com/app/apikey</a> and click on Create API key.</p>
<p>and create an API key in a new project</p>
<p>After this is done, you just need to write a REST client to get and transform data and come up with a query string to a Gemini AI. Easy peasy 😁</p>
<p>For the ease of this example, let's work with the following simple class</p>
<pre class="codeblock-container" idlang="0" lang="ObjectScript" tabsize="4"><code class="language-cls hljs cos"><span class="hljs-keyword">Class</span> Restaurant.Dish <span class="hljs-keyword">Extends</span> (<span class="hljs-built_in">%Persistent</span>, <span class="hljs-built_in">%JSON.Adaptor</span>)
{
<span class="hljs-keyword">Property</span> Name <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span><span class="hljs-comment">;</span>
<span class="hljs-keyword">Property</span> Description <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>(MAXLEN = <span class="hljs-number">1000</span>)<span class="hljs-comment">;</span>
<span class="hljs-keyword">Property</span> Category <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span><span class="hljs-comment">;</span>
<span class="hljs-keyword">Property</span> Price <span class="hljs-keyword">As</span> <span class="hljs-built_in">%Float</span><span class="hljs-comment">;</span>
<span class="hljs-keyword">Property</span> Currency <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span><span class="hljs-comment">;</span>
<span class="hljs-keyword">Property</span> Calories <span class="hljs-keyword">As</span> <span class="hljs-built_in">%Integer</span><span class="hljs-comment">;</span>
}</code></pre>
<p>In general, it would be really simple to use the built-in <code>%Populate</code> mechanism and be done with it. But in bigger projects you will get a lot of properties which are not so easily automatically populated with meaningful data.</p>
<p>Anyway, now that we have the class, let's think about the wording of a query to Gemini. Let's say we write the following query:</p>
<pre class="codeblock-container" idlang="3" lang="JSON" tabsize="4"><code class="language-json hljs">{<span class="hljs-attr">"contents"</span>: [{
<span class="hljs-attr">"parts"</span>:[{
<span class="hljs-attr">"text"</span>: <span class="hljs-string">"Write a json object that contains a field Dish which is an array of 10 elements. Each element contains Name, Description, Category, Price, Currency, Calories of the Restaurant Dish."</span>}]}]}</code></pre>
<p>If we send this request to <a href="https://generativelanguage.googleapis.com/v1beta/models/gemini-pro:generateContent?key=APIKEY" target="_blank">https://generativelanguage.googleapis.com/v1beta/models/gemini-pro:generateContent?key=APIKEY</a> we will get something like:</p>
<div class="spoiler">
<div class="spoiler-title">
<div class="spoiler-toggle show-icon"> </div>
Spoiler</div>
<div class="spoiler-content" style="display: none;">
<pre class="codeblock-container" idlang="3" lang="JSON" tabsize="4"><code class="language-json hljs">{
<span class="hljs-attr">"Dish"</span>: [
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 1"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A delicious dish with a unique flavor."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Main Course"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">15</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">500</span>
},
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 2"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A flavorful dish with a spicy kick."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Appetizer"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">10</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">300</span>
},
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 3"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A hearty dish with a comforting flavor."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Main Course"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">20</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">600</span>
},
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 4"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A refreshing dish with a zesty flavor."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Salad"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">12</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">250</span>
},
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 5"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A sweet dish with a decadent flavor."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Dessert"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">8</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">400</span>
},
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 6"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A savory dish with a smoky flavor."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Main Course"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">18</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">550</span>
},
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 7"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A light dish with a fresh flavor."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Appetizer"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">9</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">200</span>
},
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 8"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A hearty dish with a comforting flavor."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Soup"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">11</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">350</span>
},
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 9"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A refreshing dish with a zesty flavor."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Salad"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">14</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">300</span>
},
{
<span class="hljs-attr">"Name"</span>: <span class="hljs-string">"Dish 10"</span>,
<span class="hljs-attr">"Description"</span>: <span class="hljs-string">"A sweet dish with a decadent flavor."</span>,
<span class="hljs-attr">"Category"</span>: <span class="hljs-string">"Dessert"</span>,
<span class="hljs-attr">"Price"</span>: <span class="hljs-number">10</span>,
<span class="hljs-attr">"Currency"</span>: <span class="hljs-string">"$"</span>,
<span class="hljs-attr">"Calories"</span>: <span class="hljs-number">450</span>
}
]
}</code></pre>
</div>
</div>
<p>Already not bad. Not bad at all! Now that I have the wording of my query, I need to generate it as automatically as possible, call it and process the result.</p>
<p>Next step - generating the query. Using the very useful article on <a href="https://community.intersystems.com/post/how-get-property-definitions-written-class-programmatically" target="_blank">how to get the list of properties of a class</a> we can generate automatically most of the query.</p>
<pre class="codeblock-container" idlang="0" lang="ObjectScript" tabsize="4"><code class="language-cls hljs cos"><span class="hljs-keyword">ClassMethod</span> GenerateClassDesc(classname <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>) <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>
{
<span class="hljs-keyword">set</span> cls=<span class="hljs-keyword">##class</span>(<span class="hljs-built_in">%Dictionary.CompiledClass</span>).<span class="hljs-built_in">%OpenId</span>(classname,,.status)
<span class="hljs-keyword">set</span> <span class="hljs-keyword">x</span>=cls.Properties
<span class="hljs-keyword">set</span> profprop = <span class="hljs-built_in">$lb</span>()
<span class="hljs-keyword">for</span> i=<span class="hljs-number">3</span>:<span class="hljs-number">1</span>:<span class="hljs-keyword">x</span>.Count() {
<span class="hljs-keyword">set</span> prop=<span class="hljs-keyword">x</span>.GetAt(i)
<span class="hljs-keyword">set</span> <span class="hljs-built_in">$list</span>(profprop, i-<span class="hljs-number">2</span>) = prop.Name
}
<span class="hljs-keyword">quit</span> <span class="hljs-built_in">$listtostring</span>(profprop, <span class="hljs-string">", "</span>)
}
<span class="hljs-keyword">ClassMethod</span> GenerateQuery(qty <span class="hljs-keyword">As</span> <span class="hljs-built_in">%Numeric</span>) <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span> [ Language = objectscript ]
{
<span class="hljs-keyword">set</span> classname = ..<span class="hljs-built_in">%ClassName</span>(<span class="hljs-number">1</span>)
<span class="hljs-keyword">set</span> str = <span class="hljs-string">"Write a json object that contains a field "</span>_<span class="hljs-built_in">$piece</span>(classname, <span class="hljs-string">"."</span>, <span class="hljs-number">2</span>)_
<span class="hljs-string">" which is an array of "</span>_qty_<span class="hljs-string">" elements. Each element contains "</span>_
<span class="hljs-built_in">..GenerateClassDesc</span>(classname)_<span class="hljs-string">" of a "</span>_<span class="hljs-built_in">$translate</span>(classname, <span class="hljs-string">"."</span>, <span class="hljs-string">" "</span>)_<span class="hljs-string">". "</span>
<span class="hljs-keyword">quit</span> str
}</code></pre>
<p>When dealing with complex relationships between classes it may be easier to use the object constructor to link different objects together or to use a built-in mechanism of <code>%Library.Ppulate</code>.</p>
<p>Following step is to call the Gemini RESTful service and process the resulting JSON.</p>
<pre class="codeblock-container" idlang="0" lang="ObjectScript" tabsize="4"><code class="language-cls hljs cos"><span class="hljs-keyword">ClassMethod</span> CallService() <span class="hljs-keyword">As</span> <span class="hljs-built_in">%String</span>
{
<span class="hljs-keyword">Set</span> request = <span class="hljs-built_in">..GetLink</span>()
<span class="hljs-keyword">set</span> query = <span class="hljs-string">"{""contents"": [{""parts"":[{""text"": """</span>_<span class="hljs-built_in">..GenerateQuery</span>(<span class="hljs-number">20</span>)_<span class="hljs-string">"""}]}]}"</span>
<span class="hljs-keyword">do</span> request.EntityBody.<span class="hljs-keyword">Write</span>(query)
<span class="hljs-keyword">set</span> request.ContentType = <span class="hljs-string">"application/json"</span>
<span class="hljs-keyword">set</span> sc = request.Post(<span class="hljs-string">"v1beta/models/gemini-pro:generateContent?key=<YOUR KEY HERE>"</span>)
<span class="hljs-keyword">if</span> <span class="hljs-built_in">$$$ISOK</span>(sc) {
<span class="hljs-keyword">Set</span> response = request.HttpResponse.Data.<span class="hljs-keyword">Read</span>()
<span class="hljs-keyword">set</span> p = <span class="hljs-keyword">##class</span>(<span class="hljs-built_in">%DynamicObject</span>).<span class="hljs-built_in">%FromJSON</span>(response)
<span class="hljs-keyword">set</span> iter = p.candidates.<span class="hljs-built_in">%GetIterator</span>()
<span class="hljs-keyword">do</span> iter.<span class="hljs-built_in">%GetNext</span>(.key, .value, .type )
<span class="hljs-keyword">set</span> iter = value.content.parts.<span class="hljs-built_in">%GetIterator</span>()
<span class="hljs-keyword">do</span> iter.<span class="hljs-built_in">%GetNext</span>(.key, .value, .type )
<span class="hljs-keyword">set</span> obj = <span class="hljs-keyword">##class</span>(<span class="hljs-built_in">%DynamicObject</span>).<span class="hljs-built_in">%FromJSON</span>(<span class="hljs-built_in">$Extract</span>(value.text,<span class="hljs-number">8</span>,*-<span class="hljs-number">3</span>))
<span class="hljs-keyword">set</span> dishes = obj.Dish
<span class="hljs-keyword">set</span> iter = dishes.<span class="hljs-built_in">%GetIterator</span>()
<span class="hljs-keyword">while</span> iter.<span class="hljs-built_in">%GetNext</span>(.key, .value, .type ) {
<span class="hljs-keyword">set</span> dish = <span class="hljs-keyword">##class</span>(Restaurant.Dish).<span class="hljs-built_in">%New</span>()
<span class="hljs-keyword">set</span> sc = dish.<span class="hljs-built_in">%JSONImport</span>(value.<span class="hljs-built_in">%ToJSON</span>())
<span class="hljs-keyword">set</span> sc = dish.<span class="hljs-built_in">%Save</span>()
}
}
}</code></pre>
<p>Of course, since it's just an example, don't forget to add status checks where necessary.</p>
<p>Now, when I run it, I get a pretty impressive result in my database. Let's run a SQL query to see the data.</p>
<p>The description and category correspond to the name of the dish. Moreover, prices and calories look correct as well. Which means that I actually get a database, filled with reasonably real looking data. And the results of the queries that I'm going to run are going to resemble the real results.</p>
<p>Of course, a huge drawback of this approach is the necessity of writing a query to a generative AI and the fact that it takes time to generate the result. But the actual data may be worth it. Anyway, it is for you to decide 😉</p>
<div class="spoiler">
<div class="spoiler-title">
<div class="spoiler-toggle show-icon"> </div>
P.S.</div>
<div class="spoiler-content" style="display: none;">At this point Gemini API is available in a <a href="https://ai.google.dev/available_regions" target="_blank">limited number of countries and territories</a> listed below:
<ul>
<li>Algeria</li>
<li>American Samoa</li>
<li>Angola</li>
<li>Anguilla</li>
<li>Antarctica</li>
<li>Antigua and Barbuda</li>
<li>Argentina</li>
<li>Armenia</li>
<li>Aruba</li>
<li>Australia</li>
<li>Azerbaijan</li>
<li>The Bahamas</li>
<li>Bahrain</li>
<li>Bangladesh</li>
<li>Barbados</li>
<li>Belize</li>
<li>Benin</li>
<li>Bermuda</li>
<li>Bhutan</li>
<li>Bolivia</li>
<li>Botswana</li>
<li>Brazil</li>
<li>British Indian Ocean Territory</li>
<li>British Virgin Islands</li>
<li>Brunei</li>
<li>Burkina Faso</li>
<li>Burundi</li>
<li>Cabo Verde</li>
<li>Cambodia</li>
<li>Cameroon</li>
<li>Caribbean Netherlands</li>
<li>Cayman Islands</li>
<li>Central African Republic</li>
<li>Chad</li>
<li>Chile</li>
<li>Christmas Island</li>
<li>Cocos (Keeling) Islands</li>
<li>Colombia</li>
<li>Comoros</li>
<li>Cook Islands</li>
<li>Côte d'Ivoire</li>
<li>Costa Rica</li>
<li>Curaçao</li>
<li>Democratic Republic of the Congo</li>
<li>Djibouti</li>
<li>Dominica</li>
<li>Dominican Republic</li>
<li>Ecuador</li>
<li>Egypt</li>
<li>El Salvador</li>
<li>Equatorial Guinea</li>
<li>Eritrea</li>
<li>Eswatini</li>
<li>Ethiopia</li>
<li>Falkland Islands (Islas Malvinas)</li>
<li>Fiji</li>
<li>Gabon</li>
<li>The Gambia</li>
<li>Georgia</li>
<li>Ghana</li>
<li>Gibraltar</li>
<li>Grenada</li>
<li>Guam</li>
<li>Guatemala</li>
<li>Guernsey</li>
<li>Guinea</li>
<li>Guinea-Bissau</li>
<li>Guyana</li>
<li>Haiti</li>
<li>Heard Island and McDonald Islands</li>
<li>Honduras</li>
<li>India</li>
<li>Indonesia</li>
<li>Iraq</li>
<li>Isle of Man</li>
<li>Israel</li>
<li>Jamaica</li>
<li>Japan</li>
<li>Jersey</li>
<li>Jordan</li>
<li>Kazakhstan</li>
<li>Kenya</li>
<li>Kiribati</li>
<li>Kyrgyzstan</li>
<li>Kuwait</li>
<li>Laos</li>
<li>Lebanon</li>
<li>Lesotho</li>
<li>Liberia</li>
<li>Libya</li>
<li>Madagascar</li>
<li>Malawi</li>
<li>Malaysia</li>
<li>Maldives</li>
<li>Mali</li>
<li>Marshall Islands</li>
<li>Mauritania</li>
<li>Mauritius</li>
<li>Mexico</li>
<li>Micronesia</li>
<li>Mongolia</li>
<li>Montserrat</li>
<li>Morocco</li>
<li>Mozambique</li>
<li>Namibia</li>
<li>Nauru</li>
<li>Nepal</li>
<li>New Caledonia</li>
<li>New Zealand</li>
<li>Nicaragua</li>
<li>Niger</li>
<li>Nigeria</li>
<li>Niue</li>
<li>Norfolk Island</li>
<li>Northern Mariana Islands</li>
<li>Oman</li>
<li>Pakistan</li>
<li>Palau</li>
<li>Palestine</li>
<li>Panama</li>
<li>Papua New Guinea</li>
<li>Paraguay</li>
<li>Peru</li>
<li>Philippines</li>
<li>Pitcairn Islands</li>
<li>Puerto Rico</li>
<li>Qatar</li>
<li>Republic of the Congo</li>
<li>Rwanda</li>
<li>Saint Barthélemy</li>
<li>Saint Kitts and Nevis</li>
<li>Saint Lucia</li>
<li>Saint Pierre and Miquelon</li>
<li>Saint Vincent and the Grenadines</li>
<li>Saint Helena, Ascension and Tristan da Cunha</li>
<li>Samoa</li>
<li>São Tomé and Príncipe</li>
<li>Saudi Arabia</li>
<li>Senegal</li>
<li>Seychelles</li>
<li>Sierra Leone</li>
<li>Singapore</li>
<li>Solomon Islands</li>
<li>Somalia</li>
<li>South Africa</li>
<li>South Georgia and the South Sandwich Islands</li>
<li>South Korea</li>
<li>South Sudan</li>
<li>Sri Lanka</li>
<li>Sudan</li>
<li>Suriname</li>
<li>Taiwan</li>
<li>Tajikistan</li>
<li>Tanzania</li>
<li>Thailand</li>
<li>Timor-Leste</li>
<li>Togo</li>
<li>Tokelau</li>
<li>Tonga</li>
<li>Trinidad and Tobago</li>
<li>Tunisia</li>
<li>Türkiye</li>
<li>Turkmenistan</li>
<li>Turks and Caicos Islands</li>
<li>Tuvalu</li>
<li>Uganda</li>
<li>United Arab Emirates</li>
<li>United States</li>
<li>United States Minor Outlying Islands</li>
<li>U.S. Virgin Islands</li>
<li>Uruguay</li>
<li>Uzbekistan</li>
<li>Vanuatu</li>
<li>Venezuela</li>
<li>Vietnam</li>
<li>Wallis and Futuna</li>
<li>Western Sahara</li>
<li>Yemen</li>
<li>Zambia</li>
<li>Zimbabwe</li>
</ul>
<p>If you're not in one of these countries or territories, you will get an error <code>{"error": {"code": 400, "message": "User location is not supported for the API use.", "status": "FAILED_PRECONDITION"}</code>. In this case, try <a href="https://cloud.google.com/vertex-ai#build-with-gemini">Gemini Pro in Vertex AI</a>.</p>
<p> </p>
</div>
</div>
<p>P.P.S. The first image is how Gemini imagines the "AI that writes a program to create test data" 😆</p> | intersystemsdev |
1,079,615 | Allow remote access to postgresql database | Allowing remote access to your PostgreSQL database can be necessary for various reasons, such as... | 0 | 2024-06-22T15:35:33 | https://dev.to/yousufbasir/allow-remote-access-to-postgresql-database-mho | postgres | Allowing remote access to your PostgreSQL database can be necessary for various reasons, such as connecting from different servers or enabling remote management.
### Step 1: Modify the PostgreSQL Configuration File
First, you need to modify the PostgreSQL configuration file to allow connections from remote hosts. This file is typically located in `/etc/postgresql/<version>/main/postgresql.conf`. Replace `<version>` with your PostgreSQL version number.
For example, if you are using PostgreSQL version 13, you would run:
```bash
sudo nano /etc/postgresql/13/main/postgresql.conf
```
Locate the following line:
```plaintext
#listen_addresses = 'localhost'
```
Uncomment this line and change `'localhost'` to `'*'` to allow connections from any IP address:
```plaintext
listen_addresses = '*'
```
### Step 2: Configure Client Authentication
Next, you need to configure PostgreSQL to accept remote connections by editing the `pg_hba.conf` file, which controls client authentication.
Open the `pg_hba.conf` file:
```bash
sudo nano /etc/postgresql/13/main/pg_hba.conf
```
Add the following line at the end of the file to allow connections from any IP address using MD5 password authentication:
```plaintext
host all all 0.0.0.0/0 md5
```
### Step 3: Restart PostgreSQL Service
For the changes to take effect, you need to restart the PostgreSQL service. Use the following command:
```bash
sudo systemctl restart postgresql
```
### Step 4: Configure Your Firewall
Ensure your firewall allows incoming connections on PostgreSQL's default port (5432). If you are using UFW (Uncomplicated Firewall), you can allow connections to this port by running:
```bash
sudo ufw allow 5432/tcp
```
### Step 5: Verify Remote Access
To verify that your PostgreSQL database is accessible remotely, you can use a PostgreSQL client tool like `psql` from a remote machine. For example:
```bash
psql -h <your_server_ip> -U <your_username> -d <your_database>
```
Replace `<your_server_ip>`, `<your_username>`, and `<your_database>` with your server’s IP address, PostgreSQL username, and database name, respectively.
### Security Considerations
Allowing remote access to your PostgreSQL database opens up potential security risks. Here are a few best practices to mitigate these risks:
1. **Use Strong Passwords:** Ensure that all your PostgreSQL user accounts have strong passwords.
2. **Restrict IP Addresses:** Instead of allowing connections from any IP address, restrict access to specific IP addresses or ranges by modifying the `pg_hba.conf` file.
3. **Enable SSL:** Configure PostgreSQL to use SSL for encrypted connections.
4. **Regular Updates:** Keep your PostgreSQL installation and all related packages up to date to ensure you have the latest security patches.
### Conclusion
By following these steps, you can configure your PostgreSQL database to allow remote connections. Always remember to balance accessibility with security to protect your data. With the proper configuration and security measures, remote access can be both convenient and safe. | yousufbasir |
1,897,128 | CURSORS | This HTML and CSS code creates a web page with several interactive elements and style effects. Here's... | 0 | 2024-06-22T15:34:51 | https://dev.to/myvoice/cursors-1egn | codepen | <p>This HTML and CSS code creates a web page with several interactive elements and style effects. Here's a summary of the elements and their functionalities:</p>
<p>A link to an Instagram profile with the text "hover and click".
Line break tags to add vertical space.
A button with a "glow-on-hover" class and the text "TEST ! CLICK ON ME !!!".
A level 1 heading with the text "Hover over me and highlight me!".
CSS code that defines a custom cursor for the entire page, for certain interactive elements like links and buttons, as well as for specific text-related elements like headings and paragraphs.
CSS style for links, including a transition effect for color and background when hovered.
CSS style for the button with a glow effect on hover.
CSS style for the heading with an animated underline effect on hover.
CSS style for text selection in the heading.
In summary, this page presents multiple interactive elements with visual style effects and animations to enhance the user experience.</p>
{% codepen https://codepen.io/myvoice/pen/wvZLaEr %} | myvoice |
1,897,052 | How Machine Learning Models Work - One Byte Explainer | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-22T15:32:53 | https://dev.to/praneshchow/how-machine-learning-models-work-one-byte-explainer-36n1 | devchallenge, cschallenge, computerscience, beginners | *This is a submission for [DEV Computer Science Challenge v24.06.12: One Byte Explainer](https://dev.to/challenges/cs).*
## Explainer
Machine learning is a system that learns from data and improves over time without writing extra programming. Machine learning models first train on the given data and then test the data by making decisions or predictions based on the given data.
## Additional Context
Whenever studying machine learning, we often get confused about how it works, why we need testing and training data, and the functioning of models. I simply explain: the roles of data, and how models work.
| praneshchow |
1,897,126 | What is code pollution and how to fix it - A dependency injection lesson | What is code pollution? Code pollution is an antipattern that takes place when you... | 0 | 2024-06-22T15:31:23 | https://dev.to/rogeliogamez92/what-is-code-pollution-and-how-to-fix-it-a-dependency-injection-lesson-54jd | programming, beginners, testing, csharp | ## What is code pollution?
_Code pollution_ is an antipattern that takes place when you introduce additional code to your production code base to enable unit testing. [1]
This antipattern appears in two forms:
1. As a new method only called from the unit tests.
2. As a flag that changes the behavior of a class to indicate that it is called from a unit test.
Remember that _code is a liability, not an asset_. Adding code to production for the sole purpose of unit testing decreases the project's maintainability.
## Examples of code pollution
Case 1: Adding a method that is only called from the unit tests.
```csharp
public class MyClass
{
private readonly IConfiguration _configuration;
public MyClass(IConfiguration configuration)
{
_configuration = configuration;
}
public string Run()
{
if (GetConfigurationValue() == "FooBar")
{
return "Do cool stuff";
}
return string.Empty;
}
// Only used for testing
internal string GetConfigurationValue()
{
return _configuration["ConfigurationValue"];
}
}
[TestClass]
public class MyTest()
{
[TestMethod]
public void TestConfigurationValue()
{
string configurationValue = "FooBar";
IConfiguration configuration = new ConfigurationBuilder()
.AddInMemoryCollection(
new Dictionary<string, string>() { "ConfigurationValue", configurationValue })
.Build();
MyClass myClass = new MyClass(configuration);
Assert.AreEqual(configurationValue, myClass.GetConfigurationValue());
}
}
```
Case 2: Injecting a flag to change the class or method behavior.
```csharp
public class MyClass
{
private readonly IConfiguration _configuration;
private bool _isTestEnvironment;
public MyClass() {}
internal MyClass(IConfiguration configuration, bool isTestEnvironment)
{
_configuration = configuration;
_isTestEnvironment = isTestEnvironment;
}
public void Run(string createValue, string executeValue)
{
Repository myRepository;
if (_isTestEnvironment)
{
// Stuff for test environment
myRepository = CreateTestRepository(createValue);
}
else
{
// Stuff for normal environment
myRepository = CreateRepository(_configuration, createValue);
}
myRepository.DoStuff(executeValue);
}
}
```
## How to fix code pollution
Case 1. Fixing method or property pollution.
If you are exposing private properties or methods, you are exposing implementation details. In that case, you should change your unit test to actually test the system's behavior.
```csharp
[TestClass]
public class MyTest()
{
[TestMethod]
public void TestConfigurationValue()
{
string configurationValue = "FooBar";
IConfiguration configuration = new ConfigurationBuilder()
.AddInMemoryCollection(
new Dictionary<string, string>() { "ConfigurationValue", configurationValue })
.Build();
MyClass myClass = new MyClass(configuration);
Assert.AreEqual("Do cool stuff", myClass.Run());
}
}
```
Case 2. Fixing injection pollution.
If you need to inject a parameter or configuration to test the system, you are not applying dependency injection properly.
In our example, we use a `bool` flag to indicate our program to create a test `Repository` instead of the normal one to avoid using production dependencies `IConfiguration`.
Instead, we should inject `Repository` as a method dependency, or inject a `RepositoryBuilder` as a constructor dependency.
```csharp
// Method injection
public class MyClass
{
public MyClass() {}
public void Run(Repository repository, string executeValue)
{
repository.DoStuff(executeValue);
}
}
// Constructor injection
public class MyClass
{
private readonly RepositoryBuilder _repositoryBuilder;
public MyClass(RepositoryBuilder repositoryBuilder)
{
_repositoryBuilder = repositoryBuilder;
}
public void Run(string executeValue)
{
_respositoryBuilder.Build().DoStuff(executeValue);
}
}
```
This way, we can inject the testing repo from our unit test, and the production repo in the production code base.
## References
1. Khorikov, V. (2020). _Unit testing principles, practices, and patterns_. Manning Publications Company.
| rogeliogamez92 |
1,897,125 | Day 26 of my progress as a vue dev | About today Today was one of the most productive days I've had in a while and it felt great to get a... | 0 | 2024-06-22T15:26:24 | https://dev.to/zain725342/day-26-of-my-progress-as-a-vue-dev-2gee | webdev, vue, typescript, tailwindcss | **About today**
Today was one of the most productive days I've had in a while and it felt great to get a lot of work done. I'm surprised how much you can do if you don't have any distractions and you set your mind to something. I got my landing page completed and spent a lot of time studying many concepts on generative AI which was fun.
**What's next?**
I will try absolute best to continue this pace and will try to up number of productive of hours on daily basis. I have one more landing page I want to work on and will do that before getting started on my portfolio landing page.
**Improvements required**
I think I have to re-figure my daily schedule in order to fit my work hours and get as many productive sessions in day as I can.
Wish me luck! | zain725342 |
1,897,119 | Data Synchronization in Microservices with PostgreSQL, Debezium, and NATS: A Practical Guide | In modern software development, the microservices architecture has become popular for its scalability... | 0 | 2024-06-22T15:25:03 | https://learn.glassflow.dev/blog/usecases/microservices-data-synchronization-using-postgresql-debezium-and-nats | programming, tutorial, microservices, opensource | In modern software development, the microservices architecture has become popular for its scalability and flexibility. Despite its benefits, it brings significant challenges, particularly in [data synchronization](https://learn.glassflow.dev/blog/articles/event-driven-design-rethinking-systems-architecture) across various services. By leveraging PostgreSQL, Debezium, and NATS, we can establish an efficient and reliable method for synchronizing data across microservices.
This guide provides a step-by-step approach to building a data synchronization stack using popular technologies. You'll get an introduction to Change Data Capture (CDC), understand the challenges, and receive ready-to-use code snippets.
## The Challenge of Data Synchronization in Microservices
Microservices are designed to be loosely coupled and independently deployable, with each having its own database. While this independence is advantageous, it presents a significant challenge in maintaining data consistency throughout the system. Traditional batch processing methods, such as ETL (extract, transform, load), can be cumbersome and often fail to provide real-time updates, which are essential for many modern applications.
## Introduction to Change Data Capture (CDC)
Change Data Capture (CDC) is a process that tracks all data changes in a database and extracts them so they can be reflected in other systems, ensuring they have accurate and up-to-date copies.
For a more in-depth discussion on this topic, refer to our previous article, "[Understanding Database Synchronization: An Overview of Change Data Capture.](https://learn.glassflow.dev/blog/articles/understanding-database-synchronization)"
## The Pipeline Components
Although PostgreSQL is used as the source database in this example, the same principles can be applied to other databases like MySQL or MariaDB. Below are brief descriptions of the components used:
### PostgreSQL: A Robust Database Solution
PostgreSQL is a powerful, open-source object-relational database system known for its advanced features and reliability. In a microservices architecture, each service uses its own PostgreSQL instance, ensuring data isolation and integrity.
### Debezium: Change Data Capture
Debezium is an open-source platform for Change Data Capture (CDC). It monitors databases and captures row-level changes, emitting them as event streams. When integrated with PostgreSQL, Debezium captures every change made to the database in real time.
### NATS: The Messaging Backbone
NATS is a central messaging system known for its lightweight design, high throughput, and low latency. It acts as the conduit for communicating data changes across different microservices.
## Setting Up PostgreSQL
To enable CDC with PostgreSQL, several key concepts need to be understood:
Database Write-Ahead Log (WAL): WAL ensures data integrity by logging all changes before they are applied to the database files. In PostgreSQL, WAL records every change, maintaining the atomicity and durability of transactions.
Replication Slot: Replication slots are crucial for streaming replication. They ensure that the master server retains the necessary WAL logs for replicas, even if the replicas are temporarily disconnected. PostgreSQL supports two types of replication slots: physical and logical.
To configure PostgreSQL for CDC, the wal_level must be set to logical. Additionally, you may need to adjust the max_level_senders and max_replication_slots settings. Below is an example of a docker-compose file for setting up PostgreSQL:
```yaml
version: '3.9'
services:
postgres:
image: postgres:latest
command: "-c wal_level=logical -c max_wal_senders=5 -c max_replication_slots=5"
environment:
POSTGRES_DB: glassflowdb
POSTGRES_USER: glassflowuser
POSTGRES_PASSWORD: glassflow
ports:
- "5432:5432"
volumes:
- ./data/postgres:/var/lib/postgresql/data
```
We can now start the database by running:
```bash
docker compose up
```
Let’s create a simple table that we will track later on. Here is an example of how to create a table in PostgreSQL:
```sql
$ psql -h 127.0.0.1 -U glassflowuser -d glassflowdb
Password for user glassflowuser:
psql (14.10, server 16.1 (Debian 16.1-1.pgdg120+1))
WARNING: psql major version 14, server major version 16.
Some psql features might not work.
Type "help" for help.
glassflowdb=# CREATE TABLE accounts (
user_id serial PRIMARY KEY,
username VARCHAR ( 50 ) UNIQUE NOT NULL,
password VARCHAR ( 50 ) NOT NULL,
email VARCHAR ( 255 ) UNIQUE NOT NULL,
created_on TIMESTAMP NOT NULL,
last_login TIMESTAMP
);
```
## Setting up NATS
Update the docker compose yaml to include the NATs server configuration:
```yaml
nats:
image: nats:latest
ports:
- "4222:4222"
command:
- "--debug"
- "--http_port=8222"
- "--js"
```
## Setting Up Debezium
We are going to use a ready-to-use version of Debezium. Update the docker compose yaml to include the Debezium service configuration:
```yaml
debezium:
image: docker.io/debezium/server:latest
volumes:
- ./debezium/conf:/debezium/conf
depends_on:
- postgres
- nats
```
To get it working, we need to define a configuration for Debezium. This configuration is specified in a file named `application.properties`.
```properties
debezium.source.connector.class=io.debezium.connector.postgresql.PostgresConnector
debezium.source.offset.storage.file.filename=data/offsets.dat
debezium.source.offset.flush.interval.ms=0
debezium.source.database.hostname=postgres
debezium.source.database.port=5432
debezium.source.database.user=glassflowuser
debezium.source.database.password=glassflow
debezium.source.database.dbname=glassflowdb
debezium.source.topic.prefix=glassflowtopic
debezium.source.plugin.name=pgoutput
debezium.sink.type=nats-jetstream
debezium.sink.nats-jetstream.url=nats://nats:4222
debezium.sink.nats-jetstream.create-stream=true
debezium.sink.nats-jetstream.subjects=postgres.*.*
```
It is important to note that the source connector for PostgreSQL is typically set up using Debezium's default decoderbufs plugin. In this article, however, we will use pgoutput instead, so we need to set debezium.source.plugin.name=pgoutput.
### How Debezium Achieves CDC with PostgreSQL
Before proceeding, let's discuss how Debezium implements Change Data Capture (CDC) with PostgreSQL.
1. Debezium connects to PostgreSQL as a replication client, which involves setting up a Debezium connector for PostgreSQL. This requires PostgreSQL to be configured with wal_level set to logical.
2. When set up, Debezium creates a logical replication slot in PostgreSQL. This slot ensures that relevant WAL entries are retained until Debezium processes them, preventing data loss even if the Debezium connector goes offline temporarily.
3. Debezium reads changes from the WAL through the replication slot. It decodes these changes from their binary format into a structured format (e.g., JSON) that represents the SQL operations.
4. Each decoded change is then emitted as a separate event. These events contain all necessary information about the database changes, such as the type of operation (INSERT, UPDATE, DELETE), the affected table, and the old and new values of the modified rows.
5. Debezium acts as a NATS producer, publishing each change event to a NATS topic (usually one topic per table).
6. Consumers can subscribe to these NATS topics to receive real-time updates about database changes. This enables applications and microservices to react to data changes as they happen.
## Testing Our Setup
If everything is set up correctly, any changes made to the PostgreSQL database, such as updates to the accounts table, will be sent to NATS.
```bash
$ psql -h 127.0.0.1 -U glassflowuser -d glassflowdb
glassflowdb=# INSERT INTO "public"."accounts" ("username", "password", "email", "created_on")
VALUES ('user2', 'beseeingya', 'user2@email.com', NOW());
glassflowdb=# DELETE FROM accounts WHERE username = 'user3';
```
When we create a consumer, we can observe all the events sent by Debezium.
```bash
$ nats consumer add DebeziumStream viewer --ephemeral --pull --defaults > /dev/null
$ nats consumer next --raw --count 100 DebeziumStream viewer | jq -r '.payload'
{
"before": null,
"after": {
"user_id": 4,
"username": "user2",
"password": "beseeingya",
"email": "user2@email.com",
"created_on": 1700505308855573,
"last_login": null
},
"source": {
"version": "2.2.0.Alpha3",
"connector": "postgresql",
"name": "glassflowtopic",
"ts_ms": 1700505308860,
"snapshot": "false",
"db": "glassflowdb",
"sequence": "[\"26589096\",\"26597648\"]",
"schema": "public",
"table": "accounts",
"txId": 742,
"lsn": 26597648,
"xmin": null
},
"op": "c",
"ts_ms": 1700505309220,
"transaction": null
}
{
"before": {
"user_id": 3,
"username": "",
"password": "",
"email": "",
"created_on": 0,
"last_login": null
},
"after": null,
"source": {
"version": "2.2.0.Alpha3",
"connector": "postgresql",
"name": "glassflowtopic",
"ts_ms": 1700505331733,
"snapshot": "false",
"db": "glassflowdb",
"sequence": "[\"26598656\",\"26598712\"]",
"schema": "public",
"table": "accounts",
"txId": 743,
"lsn": 26598712,
"xmin": null
},
"op": "d",
"ts_ms": 1700505331751,
"transaction": null
}
```
## Why It Matters
Integrating Debezium with PostgreSQL and NATS for Change Data Capture (CDC) is essential for building advanced, real-time data pipelines. Once set up, this integration offers numerous possibilities for data utilization and integration across various systems and applications. For instance, change events captured from the database can be streamed to a data lake, allowing organizations to aggregate large amounts of data in a centralized repository for complex analysis and machine learning purposes. These data streams can also be fed directly into analytics dashboards, providing real-time insights and decision-making capabilities. This is particularly useful for [monitoring key metrics](https://learn.glassflow.dev/docs/tutorials/use-cases/real-time-clickstream-analytics), [detecting anomalies](https://learn.glassflow.dev/docs/tutorials/use-cases/real-time-log-data-anomaly-detection), or understanding user behavior in near real-time.
Additionally, the system can trigger automated workflows in response to specific data changes, such as sending notifications or updating other systems. The flexibility and scalability of this setup make it an ideal foundation for building comprehensive and responsive data-driven ecosystems, catering to a wide range of use cases from business intelligence to operational monitoring.
## Conclusions
Synchronizing data across microservices can be challenging, but using PostgreSQL, Debezium, and NATS offers a robust solution. This setup ensures real-time data consistency across services while adhering to the principles of microservices architecture. By leveraging these technologies, we can build scalable, resilient, and efficient systems that meet the demands of modern application development.
Remember, this guide is a starting point. Depending on your specific requirements, further customization and configuration may be necessary.
## Next
Discover various use cases of [real-time data pipelines](https://learn.glassflow.dev/docs/tutorials/use-cases) with code samples.
### About the author
Visit my blog: [www.iambobur.com](https://www.iambobur.com/) | bobur |
1,897,123 | React Interview Questions (Beginner level) | Here are some beginner-level React interview questions that you might encounter in your next... | 0 | 2024-06-22T15:24:33 | https://dev.to/sadrul_vala_315ccc7520938/react-interview-questions-beginner-level-4emj | react, javascript, interview, beginners | Here are some beginner-level React interview questions that you might encounter in your next interview. Good luck, and I hope this material proves helpful in your preparation.
## **What is React?**
React is a JavaScript library for building user interfaces, focusing on component-based architecture, virtual DOM for performance, JSX syntax for rendering, and one-way data flow. It's widely used for creating interactive web applications efficiently.
It is used for handling view layer for web and mobile apps based on components in a declarative approach.
## **What are the key characteristics of React?**
- Component-based architecture.
- Virtual DOM for efficient rendering.
- JSX for declarative UI syntax.
- Unidirectional data flow.
- Hooks for functional components.
- Rich ecosystem with libraries like Redux and React Router.
## **What is JSX?**
JSX stands for JavaScript XML. It's an extension to JavaScript syntax that allows developers to write HTML-like code within JavaScript. JSX makes it easier to create and manipulate the DOM structure in React applications.
- Combines JavaScript and HTML: JSX allows you to write HTML elements and JavaScript together in a single file.
- Syntax extension: It provides syntactic sugar for React.createElement(component, props, ...children) function calls.
- Compile-time transformation: JSX code is transformed into regular JavaScript objects during build time using tools like Babel.
> Code-snippet of JSX:
```
import React from 'react';
const element = <h1>Hello, JSX!</h1>;
function App() {
return (
<div>
<h1>Welcome to my React App</h1>
<p>This is a paragraph rendered using JSX.</p>
{element}
</div>
);
}
export default App;
```
In the above example, `<h1>Hello, JSX!</h1>` is JSX syntax that gets transformed into React.createElement('h1', null, 'Hello, JSX!') behind the scenes. This simplifies the process of writing and visualizing UI components in React applications.
## **What is state in React?**
In React, state is a built-in object that allows components to keep track of their internal data. It represents the mutable data that influences the component's rendering and behavior. The important point is whenever the state object changes, the component re-renders.
## **What are props in React?**
In React, props (short for properties) are a way of passing data from one component to another. They are similar to function arguments in JavaScript or parameters in other programming languages. Props are read-only and help to make components more dynamic and reusable by allowing them to be configured with different values.
_OR_
Data passed from a parent component to a child component. They are immutable (read-only) and allow components to be customizable and reusable.
> Example
Consider a parent component passing a name prop to a child component:
```
// ParentComponent.jsx
import React from 'react';
import ChildComponent from './ChildComponent';
function ParentComponent() {
const name = "Alice";
return (
<div>
<ChildComponent name={name} />
</div>
);
}
export default ParentComponent;
```
```
// ChildComponent.jsx
import React from 'react';
function ChildComponent(props) {
return <p>Hello, {props.name}!</p>;
}
export default ChildComponent;
```
- ParentComponent: Renders ChildComponent and passes a name prop with the value "Alice".
- ChildComponent: Receives name as a prop (props.name) and displays a greeting using that prop (Hello, {props.name}!).
> Above Example
- name is a prop passed from ParentComponent to ChildComponent.
- Props allow ChildComponent to dynamically display different names based on what ParentComponent passes.
## **What is the difference between state and props?**
> State
- Managed internally by the component itself.
- Can be updated using setState() method in class components or using Hooks in functional components.
- Changes trigger re-rendering of the component and its children.
- Mutable (can be modified within the component).
- Used for managing internal state and data that may change over time.
- Enhances component reusability when used effectively with local state management.
> Props
- Passed from parent to child component.
- Read-only (immutable) within the receiving component.
- Used to configure a component and provide data from parent to child.
- Components become more reusable as they can be configured differently via props.
- Cannot be modified by the receiving component.
- Used for passing data and callbacks between components in a component hierarchy.
## **What are react fragments?**
React Fragments provide a way to group multiple children elements without adding extra nodes to the DOM. They allow you to return multiple elements from a component's render method without needing to wrap them in a container element like a `<div>` or `<span>`. Fragments were introduced in React 16.2 as a lightweight syntax for grouping elements.
## **What is the difference between Component and Element?**
> Component
- Definition: A component is a JavaScript function or class that optionally accepts inputs (props) and returns a React element.
- Purpose: It defines reusable UI pieces.
- Types: Functional components (using functions) and class components (using ES6 classes).
- Usage: Components manage their own state (with Hooks or setState for class components) and lifecycle.
> Example
```
function Welcome(props) {
return <h1>Hello, {props.name}</h1>;
}
```
> Element
- Definition: An element is a plain object representation of a React component.
- Purpose: It describes what you want to see on the screen.
- Created with: JSX syntax or React.createElement() function.
- Immutable: Elements are immutable and represent the UI at a certain point in time.
> Example
```
const element = <h1>Hello, world!</h1>;
```
## **What is key in React?**
In React.js, the key prop is a special attribute used to give a unique identity to each element or component in an array or iterable list of children. It's primarily used by React internally to efficiently manage and update the component's UI when items are added, removed, or rearranged in a list.
Purpose of key:
**_Identifying Elements_**: When rendering multiple elements from an array or iterating over components, React uses keys to differentiate between items. This helps React determine which items have changed, are added, or are removed.
**_Optimizing Reconciliation_**: React uses keys during its reconciliation process (diffing algorithm) to minimize DOM updates. By having a stable identity for each item, React can efficiently update the UI without re-rendering unchanged components or losing component state.
## **What is prop drilling in React?**
Prop drilling in React refers to the process where props are passed from a higher-level component to a lower-level component through intermediary components that do not actually use the props themselves. This happens when data needs to be passed down multiple levels of nested components, even though some intermediate components don't need the data themselves.
Prop drilling is a common pattern in React where props are passed through multiple levels of nested components to reach a deeply nested child component that needs the data. While it's straightforward to implement, it can lead to code complexity and inefficiencies. Using React's Context API or state management libraries can provide cleaner solutions for managing and passing data across components in complex applications.
## **What are error boundaries?**
Error boundaries are React components that catch JavaScript errors anywhere in their child component tree, log those errors, and display a fallback UI instead of crashing the entire React application. They are used to manage and gracefully handle errors that occur during rendering, in lifecycle methods, and in constructors of React components.
## **What is Virtual DOM?**
The Virtual DOM (Document Object Model) is a concept in React and other virtual DOM-based libraries that represents a lightweight copy of the real DOM tree. It's a programming concept and an abstraction layer used for efficiently updating the UI.
- Definition: The Virtual DOM is a JavaScript representation of the actual DOM elements and their properties (attributes, styles, etc.) created by React.
- Purpose: It serves as an intermediary representation of the UI. When changes are made to the state or props of React components, React first updates the Virtual DOM rather than the real DOM directly.
- Working Principle: React compares the current Virtual DOM with a previous version (reconciliation process) to identify what has changed. This comparison is efficient because manipulating the Virtual DOM is faster than directly interacting with the actual browser DOM.
- Efficiency: Once React identifies the differences (diffing algorithm), it only updates the parts of the real DOM that have changed. This minimizes costly DOM manipulation operations and helps in achieving better performance.
- Example: Suppose you have a React component that updates its state. React will update the Virtual DOM first, compare it with the previous Virtual DOM state, and then apply the necessary changes to the real DOM.
## **What are the differences between controlled and uncontrolled components?**
Controlled and uncontrolled components are two different approaches to managing form input elements in React. The main differences lie in how they handle and manage state, especially with regards to form data.
> Controlled Components:
- State Handling: In controlled components, form data is handled by React state (typically within the parent component).
- Data Flow: The value of the form input elements (like `<input>`, `<textarea>`, `<select>`) is controlled by the state and is passed to the components as props.
- Event Handling: Changes to the form elements are handled using onChange event handlers, where the state is updated with each change.
> Uncontrolled Components:
- State Handling: Uncontrolled components rely on the DOM itself to manage form data.
- Ref Usage: References (ref) are typically used to access the DOM elements directly to get their values.
- Event Handling: Events like onSubmit, onClick, or directly accessing DOM events (element.value) are used to retrieve form data.
I hope these interview questions have been insightful and will help you prepare effectively, and also Feel free to bookmark 🔖 even if you don't need this for now. Best of luck in your upcoming interviews!
Follow me for more interesting posts and to fuel my writing passion!
| sadrul_vala_315ccc7520938 |
1,897,121 | Thread In Java | A thread is a small part of a process capable of execute independently. Java supports... | 0 | 2024-06-22T15:22:08 | https://dev.to/anupam_tarai_3250344e48cd/thread-in-java-2f6e | java | - A thread is a small part of a process capable of execute independently.
- Java supports multithreading, allowing a process to be divided into multiple threads. These threads can be scheduled by the CPU to execute in parallel, improving the performance of the application.
## Creation of a Thread
- We can create a thread by extending the 'Thread' class or implementing the 'Runnable' interface. Override the run method inside the thread.
## CODE
```
class A extends Thread{ //A is a thread that extends "Thread" class
public void run(){ //Override the run method
for (int i=0; i<10; i++){
System.out.println("AAAA");
try {
Thread.sleep(10);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
}
}
class B implements Runnable{ //B is a thread that impliments "Runnable" interface
public void run(){ //Override the run method
for (int i=0; i<10; i++){
System.out.println("BB");
try {
Thread.sleep(10);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
}
}
public class Server {
public static void main(String[] args){
A a = new A();
B b = new B();
Thread Tb = new Thread(b); // we need to pass that runnable into the costructor of thread class to create a thread
a.start();
try {
Thread.sleep(10);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
Tb.start();
}
}
Output:
AAAA
AAAA
BB
BB
AAAA
AAAA
BB
AAAA
BB
BB
AAAA
BB
AAAA
AAAA
BB
BB
AAAA
BB
AAAA
BB
```
Here we have two classes, A and B, both representing threads. When we start the threads using the start method, both threads begin executing in parallel.
## Methods in the Thread Class
- **start():** Starts the thread's execution; the JVM calls the thread's run method.
- **run():** Contains the code to be executed by the thread.
- **join():** Waits for the thread to die. If called on a thread, the calling thread will wait until the thread on which join was called finishes.
- **sleep(long millis):** Causes the current thread to sleep for the specified number of milliseconds.
- **interrupt():** Interrupts the thread, causing it to stop its current task and handle the interruption (if it checks for interruptions).
## CONCLUSION
> Threads are helpful in large applications that require more time and resources to execute. By dividing such applications into multiple threads and executing them in parallel, the performance of the application can be significantly increased.
_**Please comment below if I have made any mistakes or if you know any additional concepts related to this topic.**_ | anupam_tarai_3250344e48cd |
1,897,120 | ✨CSS button Hold👆🏼 Effect💫 | Check out this Pen I made! | 0 | 2024-06-22T15:22:03 | https://dev.to/myvoice/css-button-hold-effect-p65 | codepen, html, css, webdev | Check out this Pen I made!
{% codepen https://codepen.io/myvoice/pen/WNBogGL %} | myvoice |
1,897,109 | 🌟 Unlocking the Magic of JavaScript: Beyond the Basics | JavaScript. The language that powers the web, runs on servers, and even controls drones! It’s a... | 0 | 2024-06-22T15:17:16 | https://dev.to/parthchovatiya/unlocking-the-magic-of-javascript-beyond-the-basics-1jo7 | webdev, javascript, programming, beginners | JavaScript. The language that powers the web, runs on servers, and even controls drones! It’s a language that has evolved tremendously since its inception in 1995. If you're a web developer, chances are JavaScript is a significant part of your toolkit. But how well do you really know it?
In this post, we'll dive deep into some of the lesser-known features and powerful capabilities of JavaScript that will make you appreciate the language even more. Let's embark on this journey and explore the magic that makes JavaScript so unique and powerful.
## 1. 🎩 The Power of Closures
Closures are one of the most powerful features of JavaScript. They allow functions to access variables from an outer function’s scope even after the outer function has returned. This can lead to some incredibly powerful patterns.
```
function makeCounter() {
let count = 0;
return function() {
count++;
return count;
}
}
const counter = makeCounter();
console.log(counter()); // 1
console.log(counter()); // 2
console.log(counter()); // 3
```
Understanding closures can open up a world of possibilities in your code, from data encapsulation to creating factory functions.
## 2. 🚀 Async/Await: Making Asynchronous Code Synchronous
Asynchronous JavaScript was once the bane of many developers' existence, with callbacks leading to the dreaded "callback hell." Enter async/await, a syntactic sugar built on Promises that allows us to write asynchronous code in a synchronous manner.
```
async function fetchData() {
try {
let response = await fetch('https://api.example.com/data');
let data = await response.json();
console.log(data);
} catch (error) {
console.error('Error fetching data:', error);
}
}
fetchData();
```
This modern approach not only makes your code easier to read and maintain but also keeps it free from deeply nested callback structures.
## 3. 🌐 Proxies: Intercepting and Customizing Operations
Proxies are a lesser-known but incredibly powerful feature that allows you to intercept and customize operations performed on objects. This can be useful for various tasks, such as validation, formatting, or even implementing reactive programming.
```
const handler = {
get: function(target, property) {
return property in target ? target[property] : `Property ${property} not found`;
}
};
const person = new Proxy({ name: 'Alice', age: 25 }, handler);
console.log(person.name); // Alice
console.log(person.gender); // Property gender not found
```
Proxies can be a game-changer when it comes to adding dynamic behavior to your objects.
## 4. 🧩 Generators and Iterators: Advanced Control Flow
Generators provide a powerful way to handle iteration in JavaScript, allowing you to define an iterative algorithm by writing a single function whose execution is not continuous.
```
function* idGenerator() {
let id = 1;
while (true) {
yield id++;
}
}
const gen = idGenerator();
console.log(gen.next().value); // 1
console.log(gen.next().value); // 2
console.log(gen.next().value); // 3
```
Generators can pause and resume their execution, making them perfect for managing asynchronous workflows or large datasets.
## 5. 🌠 Tagged Template Literals: Custom String Interpolation
Tagged template literals give you more control over string interpolation, allowing you to create custom string processing functions. This feature can be particularly useful for things like internationalization, custom syntax parsing, or even creating domain-specific languages.
```
function highlight(strings, ...values) {
return strings.reduce((acc, str, i) => `${acc}${str}<mark>${values[i] || ''}</mark>`, '');
}
const name = 'JavaScript';
const adjective = 'awesome';
console.log(highlight`Learning ${name} is ${adjective}!`);
// Learning <mark>JavaScript</mark> is <mark>awesome</mark>!
```
With tagged template literals, the sky's the limit for what you can achieve in terms of string manipulation.
## 🌟 Conclusion
JavaScript is a language with immense depth and versatility. By exploring these advanced features, you can take your coding skills to the next level and unlock new possibilities in your projects. Whether you're managing complex asynchronous operations with async/await, adding dynamic behavior with Proxies, or creating custom string templates, there's always something new to discover.
So, what are you waiting for? Dive into these features, experiment with them, and let the magic of JavaScript enhance your coding journey!
Happy coding! 🎉
| parthchovatiya |
1,897,116 | Going Global: Building Highly Resilient Systems with Multi-Region Active-Active Architectures | Going Global: Building Highly Resilient Systems with Multi-Region Active-Active... | 0 | 2024-06-22T15:15:50 | https://dev.to/virajlakshitha/going-global-building-highly-resilient-systems-with-multi-region-active-active-architectures-3bk8 | 
# Going Global: Building Highly Resilient Systems with Multi-Region Active-Active Architectures
In today's digital landscape, high availability and fault tolerance are not just buzzwords, they're essential requirements. As businesses expand their reach and user bases grow, the need for uninterrupted service becomes paramount. This demand has driven the adoption of multi-region active-active architectures, a sophisticated approach to ensuring application resilience. This blog post delves into the world of multi-region active-active architectures on AWS, exploring their benefits, use cases, and how they stack up against solutions from other cloud providers.
### What are Multi-Region Active-Active Architectures?
Traditional disaster recovery models often rely on a single primary region with a secondary region on standby. While this approach offers basic protection against regional failures, it often comes with increased latency for users in the secondary region and potential data loss depending on the replication strategy employed.
Multi-region active-active architectures, on the other hand, fundamentally change the game. Instead of a passive secondary region, applications are deployed actively in multiple regions. Traffic is distributed across these regions, meaning users are always routed to a nearby active instance of the application.
Let's break down the core characteristics:
* **Active-Active Deployment:** Both (or all) regions handle live traffic, eliminating the concept of a passive standby region.
* **Data Replication and Synchronization:** Real-time or near real-time data replication ensures data consistency across regions. This is crucial for maintaining data integrity and application state.
* **Global Load Balancing:** Traffic is intelligently routed to the optimal region based on factors like proximity, resource availability, or even cost optimization.
### Why Choose a Multi-Region Active-Active Architecture?
The benefits of this approach are substantial:
1. **Enhanced Availability:** With workloads distributed across multiple regions, your application remains operational even if an entire AWS region experiences an outage.
2. **Reduced Latency:** By directing users to the closest active region, latency is minimized, leading to a better user experience.
3. **Disaster Recovery and Business Continuity:** In the event of a regional disruption, traffic seamlessly fails over to other active regions with minimal to no disruption.
4. **Improved Scalability:** The distributed nature allows you to scale your application horizontally across multiple regions to handle peak loads more effectively.
5. **Compliance and Data Sovereignty:** For organizations operating in multiple geographic locations, multi-region deployments can aid in meeting data residency requirements.
### Use Cases: Where Active-Active Shines
1. **Global Ecommerce Platforms:** Imagine a global online retailer. A multi-region active-active architecture ensures customers worldwide experience minimal latency and uninterrupted shopping experiences, even during peak seasons or unforeseen events. Data consistency safeguards against issues like inventory discrepancies.
2. **Financial Trading Applications:** In the fast-paced world of finance, milliseconds matter. A multi-region active-active setup ensures traders have consistent low-latency access to trading platforms and real-time market data, regardless of their location.
3. **Media Streaming Services:** By distributing content and streaming capacity across multiple regions, media companies can deliver buffer-free streaming to a global audience, even during high-demand periods.
4. **Gaming Platforms:** Latency is critical for online gaming. Active-active deployments ensure gamers enjoy responsive gameplay and a seamless online experience.
5. **Internet of Things (IoT) Applications:** For IoT devices generating vast amounts of data, a multi-region architecture provides the scalability and low latency needed to ingest, process, and analyze data from geographically dispersed devices.
### Exploring the AWS Landscape for Multi-Region Architectures
AWS offers a robust set of services for building highly resilient multi-region active-active architectures:
* **Amazon Route 53:** A highly available and scalable DNS service for routing traffic to different regions based on geolocation, latency, or health checks.
* **AWS Global Accelerator:** Improves the performance of your applications for global users by routing traffic through AWS's global network infrastructure.
* **Amazon CloudFront:** A content delivery network (CDN) that caches static and dynamic content at edge locations worldwide, reducing latency and improving content delivery speed.
* **AWS Database Services:** Services like Amazon Aurora Global Clusters, Amazon DynamoDB Global Tables, and Amazon ElastiCache for Redis Global Datastore provide mechanisms for replicating and synchronizing data across multiple AWS regions.
* **AWS Application Load Balancer (ALB) and Network Load Balancer (NLB):** These load balancing services can distribute traffic across instances in different regions based on configured health checks and routing rules.
### Multi-Region Solutions: Beyond AWS
While our focus is on AWS, it's important to acknowledge solutions provided by other cloud providers:
* **Google Cloud Platform (GCP):** GCP offers features like Cloud Load Balancing, Cloud CDN, and Cloud Spanner (a globally distributed database) for building multi-region active-active deployments.
* **Microsoft Azure:** Azure provides services like Azure Traffic Manager, Azure Front Door, and Azure Cosmos DB (a globally distributed database) for implementing multi-region architectures.
### Conclusion
Multi-region active-active architectures are essential for businesses that prioritize high availability, fault tolerance, and low latency on a global scale. With its comprehensive suite of services, AWS empowers organizations to build highly resilient applications. As a software architect, I encourage you to explore these solutions and determine the optimal approach for your specific needs.
---
**Advanced Use Case: Building a Global Real-Time Fraud Detection System**
**The Challenge:** A global financial institution needs to analyze transactions in real-time to detect and prevent fraudulent activity. The system must be highly available and operate with minimal latency to effectively combat fraud attempts in real-time.
**Solution Architecture:**
1. **Global Data Ingestion:** Transactions originating from various geographical regions are ingested into Amazon Kinesis Data Streams. Each region has its own dedicated Kinesis stream to ensure low latency data ingestion.
2. **Real-time Data Processing:** Amazon Kinesis Data Analytics (KDA) processes the incoming transaction data streams in real-time. KDA applications, deployed in each active region, utilize machine learning models to analyze transactions for fraudulent patterns.
3. **Multi-Region Data Synchronization:** To enable cross-region analysis and rule enforcement, Amazon DynamoDB Global Tables are utilized. These tables replicate transaction data and model results across all active regions, ensuring consistency and enabling a unified view of potential fraud across the globe.
4. **Global Rule Enforcement:** Based on the analysis performed by KDA and the synchronized data in DynamoDB, real-time decisions are made regarding the legitimacy of transactions. These rules can trigger actions such as flagging transactions for further review or even blocking them entirely.
5. **Centralized Monitoring and Alerting:** Amazon CloudWatch monitors the health and performance of all system components across all regions. It collects metrics, logs, and events, triggering alerts to notify administrators of any anomalies or potential issues.
**Benefits of this Architecture:**
* **Global Coverage and Low Latency:** The multi-region deployment allows for real-time analysis of transactions regardless of their origin, significantly reducing the time window for potential fraudsters to exploit.
* **High Availability and Fault Tolerance:** Even if an entire AWS region experiences an outage, the system continues to operate seamlessly in other active regions, ensuring uninterrupted fraud detection capabilities.
* **Scalability and Elasticity:** Amazon Kinesis, KDA, and DynamoDB offer the scalability to handle massive and fluctuating volumes of transaction data, ensuring optimal performance even during peak periods.
This example illustrates the power and flexibility of multi-region active-active architectures on AWS. By leveraging the right combination of services, organizations can build highly resilient, scalable, and low-latency applications capable of meeting the demands of today's global digital landscape.
| virajlakshitha | |
1,897,114 | Defining AVIF and PNG Image Formats | What Are the Differences Between AVIF and PNG? AVIF (AV1 Image File Format) and PNG... | 0 | 2024-06-22T15:14:48 | https://dev.to/msmith99994/defining-avif-and-png-image-formats-6eb | ## What Are the Differences Between AVIF and PNG?
AVIF (AV1 Image File Format) and PNG (Portable Network Graphics) are two distinct image formats that serve different purposes, each with its own set of characteristics tailored for various applications.
### AVIF
**- Compression:** AVIF uses both lossy and lossless compression based on the AV1 video codec, which offers superior compression efficiency. This results in significantly smaller file sizes compared to other formats like JPEG and even WebP.
**- Color Depth:** Supports high dynamic range (HDR) and 8-bit, 10-bit, and 12-bit color depths, which can display a wide range of colors and brightness levels.
**- Transparency:** Supports alpha channels, allowing for full transparency.
**- File Size:** Generally smaller due to highly efficient compression.
**- Use Cases:** Ideal for web use, where high quality and small file sizes are crucial for performance optimization.
### PNG
**- Compression:** PNG uses lossless compression, preserving all image data without losing quality. This results in larger file sizes compared to formats that use lossy compression.
**- Color Depth:** Supports 24-bit color and an 8-bit alpha channel, allowing for millions of colors and varying levels of transparency.
**- Transparency:** Advanced transparency support with varying levels of opacity, making it ideal for images requiring clear backgrounds or overlays.
**- File Size:** Larger than AVIF for the same image due to lossless compression.
**- Use Cases:** Preferred for web graphics, logos, icons, digital art, and images requiring high quality and transparency.
## Where Are They Used?
### AVIF
**- Web Graphics:** Ideal for high-quality images with smaller file sizes, enhancing website loading speeds and performance.
**- Photography:** Used for storing high-resolution images with minimal loss in quality.
**- Mobile Applications:** Helps in optimizing storage and performance in mobile apps by reducing image file sizes.
**- E-commerce:** Employed to showcase product images with high quality and fast loading times.
### PNG
**- Web Graphics:** Commonly used for logos, icons, and images requiring high quality and transparency.
**- Digital Art:** Preferred for images with sharp edges, text, and transparent elements.
**- Screenshots:** Frequently used for screenshots to capture exact screen details without quality loss.
**- Print Media:** Used in scenarios where high quality and lossless compression are required.
## Benefits and Drawbacks
### AVIF
**Benefits:**
**- Superior Compression:** Provides significantly smaller file sizes compared to other formats without sacrificing quality.
**- High Quality:** Supports HDR and higher bit depths, offering excellent image quality.
**- Transparency:** Includes support for alpha channels, allowing for transparency.
**- Performance Optimization:** Ideal for web use, enhancing loading speeds and overall performance.
**Drawbacks:**
**- Limited Compatibility:** Not as widely supported as older formats like PNG and JPEG.
**- Processing Power:** Requires more processing power for encoding and decoding compared to simpler formats.
**- Adoption:** Being a newer format, it is still gaining traction and widespread use.
### PNG
**Benefits:**
**- Lossless Compression:** Maintains original image quality without any loss.
**- Wide Color Range:** Supports millions of colors, suitable for detailed images.
**- Advanced Transparency:** Allows for varying levels of opacity, making it ideal for complex images.
**- Wide Compatibility:** Supported by virtually all browsers, devices, and software.
**Drawbacks:**
**- Larger File Sizes:** Can be significantly larger than AVIF files due to lossless compression.
**- No Animation Support:** Does not support animations natively (unlike GIF).
**- Efficiency:** Less efficient for high-resolution images or images requiring advanced compression techniques.
## Last Words
[AVIF and PNG ](https://cloudinary.com/tools/avif-to-png)are both valuable image formats, each with unique strengths and weaknesses. AVIF is excellent for high-quality, efficient web images, providing superior compression and smaller file sizes. PNG, on the other hand, is favored for its lossless quality and advanced transparency support, making it ideal for web graphics, digital art, and detailed images.
Understanding the differences between AVIF and PNG, and knowing how to convert between them, allows you to choose the best format for your specific needs. Whether you need the efficient compression of AVIF or the high quality and transparency of PNG, mastering these formats ensures you can handle any digital image requirement effectively.
| msmith99994 | |
1,897,112 | Zero to Hero Stable Diffusion 3 Tutorial with Amazing SwarmUI SD Web UI that Utilizes ComfyUI | Zero to Hero Stable Diffusion 3 Tutorial with Amazing SwarmUI SD Web UI that Utilizes... | 0 | 2024-06-22T15:13:13 | https://dev.to/furkangozukara/zero-to-hero-stable-diffusion-3-tutorial-with-amazing-swarmui-sd-web-ui-that-utilizes-comfyui-27hl | beginners, tutorial, ai, learning | <h1 style="margin-left:0px;"><a target="_blank" rel="noopener noreferrer" href="https://youtu.be/HKX8_F1Er_w"><strong><u>Zero to Hero Stable Diffusion 3 Tutorial with Amazing SwarmUI SD Web UI that Utilizes ComfyUI</u></strong></a></h1>
<p style="margin-left:0px;"><a target="_blank" rel="noopener noreferrer" href="https://youtu.be/HKX8_F1Er_w"><u>https://youtu.be/HKX8_F1Er_w</u></a></p>
<p style="margin-left:auto;">{% embed https://youtu.be/HKX8_F1Er_w %}</p>
<p style="margin-left:0px;">Do not skip any part of this tutorial to master how to use Stable Diffusion 3 (SD3) with the most advanced generative AI open source APP SwarmUI. Automatic1111 SD Web UI or Fooocus are not supporting the #SD3 yet. Therefore, I am starting to make tutorials for SwarmUI as well. #StableSwarmUI is officially developed by the StabilityAI and your mind will be blown after you watch this tutorial and learn its amazing features. StableSwarmUI uses #ComfyUI as the back end thus it has all the good features of ComfyUI and it brings you easy to use features of Automatic1111 #StableDiffusion Web UI with them. I really liked SwarmUI and planning to do more tutorials for it.</p>
<p style="margin-left:0px;">🔗 The Public Post (no login or account required) Shown In The Video With The Links ➡️ <a target="_blank" rel="noopener noreferrer" href="https://www.patreon.com/posts/stableswarmui-3-106135985"><u>https://www.patreon.com/posts/stableswarmui-3-106135985</u></a></p>
<p style="margin-left:0px;">0:00 Introduction to the Stable Diffusion 3 (SD3) and SwarmUI and what is in the tutorial<br>4:12 Architecture and features of SD3<br>5:05 What each different model files of Stable Diffusion 3 means<br>6:26 How to download and install SwarmUI on Windows for SD3 and all other Stable Diffusion models<br>8:42 What kind of folder path you should use when installing SwarmUI<br>10:28 If you get installation error how to notice and fix it<br>11:49 Installation has been completed and now how to start using SwarmUI<br>12:29 Which settings I change before start using SwarmUI and how to change your theme like dark, white, gray<br>12:56 How to make SwarmUI save generated images as PNG<br>13:08 How to find description of each settings and configuration<br>13:28 How to download SD3 model and start using on Windows<br>13:38 How to use model downloader utility of SwarmUI<br>14:17 How to set models folder paths and link your existing models folders in SwarmUI<br>14:35 Explanation of Root folder path in SwarmUI<br>14:52 VAE of SD3 do we need to download?<br>15:25 Generate and model section of the SwarmUI to generate images and how to select your base model<br>16:02 Setting up parameters and what they do to generate images<br>17:06 Which sampling method is best for SD3<br>17:22 Information about SD3 text encoders and their comparison<br>18:14 First time generating an image with SD3<br>19:36 How to regenerate same image<br>20:17 How to see image generation speed and step speed and more information<br>20:29 Stable Diffusion 3 it per second speed on RTX 3090 TI<br>20:39 How to see VRAM usage on Windows 10<br>22:08 And testing and comparing different text encoders for SD3<br>22:36 How to use FP16 version of T5 XXL text encoder instead of default FP8 version<br>25:27 The image generation speed when using best config for SD3<br>26:37 Why VAE of the SD3 is many times better than previous Stable Diffusion models, 4 vs 8 vs 16 vs 32 channels VAE<br>27:40 How to and where to download best AI upscaler models<br>29:10 How to use refiner and upscaler models to improve and upscale generated images<br>29:21 How to restart and start SwarmUI<br>32:01 The folders where the generated images are saved<br>32:13 Image history feature of SwarmUI<br>33:10 Upscaled image comparison<br>34:01 How to download all upscaler models at once<br>34:34 Presets feature in depth<br>36:55 How to generate forever / infinite times<br>37:13 Non-tiled upscale caused issues<br>38:36 How to compare tiled vs non-tiled upscale and decide best<br>39:05 275 SwarmUI presets (cloned from Fooocus) I prepared and the scripts I coded to prepare them and how to import those presets<br>42:10 Model browser feature<br>43:25 How to generate TensorRT engine for huge speed up<br>43:47 How to update SwarmUI<br>44:27 Prompt syntax and advanced features<br>45:35 How to use Wildcards (random prompts) feature<br>46:47 How to see full details / metadata of generated images<br>47:13 Full guide for extremely powerful grid image generation (like X/Y/Z plot)<br>47:35 How to put all downloaded upscalers from zip file<br>51:37 How to see what is happening at the server logs<br>53:04 How to continue grid generation process after interruption<br>54:32 How to open grid generation after it has been completed and how to use it<br>56:13 Example of tiled upscaling seaming problem<br>1:00:30 Full guide for image history<br>1:02:22 How to directly delete images and star them<br>1:03:20 How to use SD 1.5 and SDXL models and LoRAs<br>1:06:24 Which sampler method is best<br>1:06:43 How to use image to image<br>1:08:43 How to use edit image / inpainting<br>1:10:38 How to use amazing segmentation feature to automatically inpaint any part of images<br>1:15:55 How to use segmentation on existing images for inpainting and get perfect results with different seeds<br>1:18:19 More detailed information regarding upscaling and tiling and SD3<br>1:20:08 Seams perfect explanation and example and how to fix it<br>1:21:09 How to use queue system<br>1:21:23 How to use multiple GPUs with adding more backends<br>1:24:38 Loading model in low VRAM mode<br>1:25:10 How to fix colors over saturation<br>1:27:00 Best image generation configuration for SD3<br>1:27:44 How to apply upscale to your older generated images quickly via preset<br>1:28:39 Other amazing features of SwarmUI<br>1:28:49 Clip tokenization and rare token OHWX</p>
<p style="margin-left:auto;">
<picture>
<source srcset="https://miro.medium.com/v2/resize:fit:640/format:webp/1*wcccTUABPvJIWN1Lz9bEBQ.png 640w, https://miro.medium.com/v2/resize:fit:720/format:webp/1*wcccTUABPvJIWN1Lz9bEBQ.png 720w, https://miro.medium.com/v2/resize:fit:750/format:webp/1*wcccTUABPvJIWN1Lz9bEBQ.png 750w, https://miro.medium.com/v2/resize:fit:786/format:webp/1*wcccTUABPvJIWN1Lz9bEBQ.png 786w, https://miro.medium.com/v2/resize:fit:828/format:webp/1*wcccTUABPvJIWN1Lz9bEBQ.png 828w, https://miro.medium.com/v2/resize:fit:1100/format:webp/1*wcccTUABPvJIWN1Lz9bEBQ.png 1100w, https://miro.medium.com/v2/resize:fit:1400/format:webp/1*wcccTUABPvJIWN1Lz9bEBQ.png 1400w" type="image/webp" sizes="(min-resolution: 4dppx) and (max-width: 700px) 50vw, (-webkit-min-device-pixel-ratio: 4) and (max-width: 700px) 50vw, (min-resolution: 3dppx) and (max-width: 700px) 67vw, (-webkit-min-device-pixel-ratio: 3) and (max-width: 700px) 65vw, (min-resolution: 2.5dppx) and (max-width: 700px) 80vw, (-webkit-min-device-pixel-ratio: 2.5) and (max-width: 700px) 80vw, (min-resolution: 2dppx) and (max-width: 700px) 100vw, (-webkit-min-device-pixel-ratio: 2) and (max-width: 700px) 100vw, 700px">
<source srcset="https://miro.medium.com/v2/resize:fit:640/1*wcccTUABPvJIWN1Lz9bEBQ.png 640w, https://miro.medium.com/v2/resize:fit:720/1*wcccTUABPvJIWN1Lz9bEBQ.png 720w, https://miro.medium.com/v2/resize:fit:750/1*wcccTUABPvJIWN1Lz9bEBQ.png 750w, https://miro.medium.com/v2/resize:fit:786/1*wcccTUABPvJIWN1Lz9bEBQ.png 786w, https://miro.medium.com/v2/resize:fit:828/1*wcccTUABPvJIWN1Lz9bEBQ.png 828w, https://miro.medium.com/v2/resize:fit:1100/1*wcccTUABPvJIWN1Lz9bEBQ.png 1100w, https://miro.medium.com/v2/resize:fit:1400/1*wcccTUABPvJIWN1Lz9bEBQ.png 1400w" sizes="(min-resolution: 4dppx) and (max-width: 700px) 50vw, (-webkit-min-device-pixel-ratio: 4) and (max-width: 700px) 50vw, (min-resolution: 3dppx) and (max-width: 700px) 67vw, (-webkit-min-device-pixel-ratio: 3) and (max-width: 700px) 65vw, (min-resolution: 2.5dppx) and (max-width: 700px) 80vw, (-webkit-min-device-pixel-ratio: 2.5) and (max-width: 700px) 80vw, (min-resolution: 2dppx) and (max-width: 700px) 100vw, (-webkit-min-device-pixel-ratio: 2) and (max-width: 700px) 100vw, 700px"><img class="image_resized" style="height:auto;width:680px;" src="https://miro.medium.com/v2/resize:fit:1313/1*wcccTUABPvJIWN1Lz9bEBQ.png" alt="" width="700" height="394">
</picture>
</p> | furkangozukara |
1,897,111 | 1248. Count Number of Nice Subarrays | 1248. Count Number of Nice Subarrays Medium Given an array of integers nums and an integer k. A... | 27,523 | 2024-06-22T15:11:14 | https://dev.to/mdarifulhaque/1248-count-number-of-nice-subarrays-405o | php, leetcode, algorithms, programming | 1248\. Count Number of Nice Subarrays
Medium
Given an array of integers `nums` and an integer `k`. A continuous subarray is called nice if there are `k` odd numbers on it.
Return _the number of **nice** sub-arrays_.
**Example 1:**
- **Input:** nums = [1,1,2,1,1], k = 3
- **Output:** 2
- **Explanation:** The only sub-arrays with 3 odd numbers are [1,1,2,1] and [1,2,1,1].
**Example 2:**
- **Input:** nums = [2,4,6], k = 1
- **Output:** 0
- **Explanation:** There are no odd numbers in the array.
**Example 3:**
- **Input:** nums = [2,2,2,1,2,2,1,2,2,2], k = 2
- **Output:** 16
**Solution:**
- <code>1 <= nums.length <= 50000</code>
- <code>1 <= nums[i] <= 10^5</code>
- <code>1 <= k <= nums.length</code>
**Constraints:**
```
class Solution {
/**
* @param Integer[] $nums
* @param Integer $k
* @return Integer
*/
function numberOfSubarrays($nums, $k) {
$r = array(0, 0);
$res = 0;
$pre = 0;
$cur = 0;
for($i = 0; $i < count($nums); $i++){
$r[$nums[$i] & 1]++;
if($r[1] == $k){
$pre = $cur;
}
while($r[1] == $k){
$r[$nums[$cur] & 1]--;
$cur++;
}
$res += $cur - $pre;
}
return $res;
}
}
```
**Contact Links**
- **[LinkedIn](https://www.linkedin.com/in/arifulhaque/)**
- **[GitHub](https://github.com/mah-shamim)**
| mdarifulhaque |
1,897,105 | What Is Lightroom Mod APK? | Introduction In today's digital age, photo editing has become a significant part of our... | 0 | 2024-06-22T14:52:54 | https://dev.to/lightroom_modapk_7a58397/what-is-lightroom-mod-apk-590l | mod, apk, appsync, appconfig | ## Introduction
In today's digital age, photo editing has become a significant part of our daily lives. From social media influencers to professional photographers, everyone relies on powerful editing tools to enhance their images. Adobe Lightroom is one such tool, known for its comprehensive features and user-friendly interface. But what if you could access all of Lightroom's premium features without paying a dime? Enter **[Lightroom Mod APK](https://lightroommodapps.com/)**. This article will explore what Lightroom Mod APK is, its features, benefits, and potential drawbacks.
Understanding Lightroom
Overview of Adobe Lightroom
Adobe Lightroom is a powerful photo editing software developed by Adobe Inc. It is part of the Adobe Creative Cloud suite and is widely used for its extensive range of editing tools and capabilities. Lightroom allows users to enhance and organize their photos, offering features like advanced color grading, exposure adjustment, and professional presets.
Key Features of Lightroom
Advanced Editing Tools: Lightroom provides a variety of tools for detailed photo editing, including exposure, contrast, color adjustments, and more.
Presets and Filters: Users can apply pre-designed filters and presets to their photos, making editing quicker and easier.
Non-Destructive Editing: Edits are stored separately from the original photo, allowing users to revert back to the original at any time.
Cloud Storage: Lightroom offers cloud storage, enabling users to access their photos and edits from any device.
Popularity and User Base
With millions of users worldwide, Adobe Lightroom has become a staple for both amateur and professional photographers. Its ease of use and powerful features make it a preferred choice for photo editing.
What is a Mod APK?
Definition of Mod APK
A Mod APK is a modified version of an original Android application package (APK). These modified versions are created by third-party developers and often include additional features, unlocked premium content, or other enhancements not available in the original version.
Difference Between Original and Modified APKs
Original APKs: These are the official versions released by the developers and are typically available on app stores like Google Play.
Modified APKs: These versions are altered to provide additional features or remove restrictions. They are not available on official app stores and must be downloaded from third-party sources.
Legal and Ethical Considerations
Using Mod APKs can be legally and ethically questionable. Modifying and distributing an app without the developer's permission can violate copyright laws and terms of service agreements. Additionally, using these versions can expose users to security risks.
Features of Lightroom Mod APK
Premium Features Unlocked
Lightroom Mod APK offers access to all premium features without requiring a subscription. This includes advanced editing tools, exclusive presets, and more.
No Subscription Needed
Users can enjoy the full capabilities of Lightroom without paying for a monthly or yearly subscription, making it a cost-effective option for those on a budget.
Advanced Editing Tools
The Mod APK version provides the same powerful editing tools as the original app, such as selective adjustments, healing brush, and geometry tools.
Presets and Filters
Access to a vast library of presets and filters allows users to apply professional-grade edits with a single tap, enhancing the editing process.
Cloud Storage Benefits
Some Mod APKs also offer additional cloud storage, enabling users to store and sync their edited photos across multiple devices without any extra cost.
How to Download Lightroom Mod APK
Step-by-Step Guide
Search for "Lightroom Mod APK" on a trusted website.
Download the APK file to your device.
Ensure your device settings allow installations from unknown sources.
Open the downloaded file and follow the installation prompts.
Trusted Sources for Downloading
It's crucial to download Mod APKs from reputable sources to minimize security risks. Look for sites with positive reviews and high download counts.
Precautions to Take
Always use antivirus software to scan downloaded files and avoid providing sensitive information within the app.
Installation Process
Enabling Unknown Sources on Your Device
To install a Mod APK, you'll need to enable installations from unknown sources in your device’s settings.
Detailed Installation Steps
Go to Settings > Security.
Enable "Unknown Sources".
Locate the downloaded APK file and tap to install.
Follow the on-screen instructions.
Common Issues and Troubleshooting
Some users may encounter issues such as installation errors or app crashes. Re-downloading the APK or restarting the device can often resolve these problems.
Advantages of Using Lightroom Mod APK
Cost Savings
One of the main advantages is the cost savings, as users can access premium features without paying for a subscription.
Access to Premium Features
Users can enjoy all the advanced features of Lightroom, making it easier to perform high-quality edits.
Enhanced Editing Experience
With unlocked features and no subscription fees, the editing experience is significantly enhanced.
Disadvantages of Using Lightroom Mod APK
Security Risks
Downloading and installing Mod APKs can expose your device to malware and other security threats.
Potential Legal Issues
Using a Mod APK can violate the app’s terms of service, potentially leading to account bans or legal action.
Lack of Official Support
Since Mod APKs are not officially supported, users cannot seek help from Adobe if they encounter issues.
Comparison: Lightroom vs. Lightroom Mod APK
Feature Comparison
While both versions offer similar features, the Mod APK provides premium features for free, which the official version requires a subscription for.
User Experience Comparison
The user experience can vary, with some users preferring the security and support of the official app, while others enjoy the free premium features of the Mod APK.
Which One Should You Choose?
Choosing between the two depends on your priorities—whether you value cost savings and premium features or security and official support.
User Experiences and Reviews
Testimonials from Users
Many users appreciate the cost savings and premium features of Lightroom Mod APK. However, others express concerns about security risks.
Common Feedback and Ratings
Feedback often highlights the enhanced editing capabilities, but security and ethical concerns are commonly mentioned.
Frequently Asked Questions (FAQs)
Is Lightroom Mod APK Safe to Use?
Safety depends on the source of the APK. Downloading from reputable sites reduces the risk, but it’s not entirely risk-free.
Can I Get Banned for Using a Mod APK?
Using a Mod APK can violate terms of service, potentially leading to account bans.
How Often is Lightroom Mod APK Updated?
Updates depend on the creators of the Mod APK and may not be as frequent as the official app.
What Devices are Compatible with Lightroom Mod APK?
Most Android devices are compatible, but compatibility issues can vary based on the APK version.
Can I Sync Lightroom Mod APK with Other Devices?
Syncing features might be limited or unavailable, depending on the Mod APK version.
Conclusion
**[Lightroom Mod APK Download](https://lightroommodapps.com/)** offers a compelling alternative to the official app by providing premium features for free. However, it comes with risks such as security vulnerabilities and potential legal issues. Users must weigh these pros and cons to decide if it’s the right choice for their editing needs. | lightroom_modapk_7a58397 |
1,897,076 | Top State management libs for React Native ✨ | State Management in React Native: A Comprehensive Guide State management is a crucial... | 0 | 2024-06-22T14:49:52 | https://dev.to/manjotdhiman/top-state-management-libs-for-react-native-1dl5 | reactnative, redux, alternative, statemanagement | ### State Management in React Native: A Comprehensive Guide
State management is a crucial aspect of developing robust and scalable React Native applications. It involves managing the state of your app, ensuring that your components reflect the correct data at all times. In this article, I'll explore various state management techniques in React Native, comparing different libraries and approaches to help you choose the best one for your needs.
#### Understanding State in React Native
In React Native, state refers to a data structure that determines how a component renders and behaves. State is mutable, meaning it can change over time, usually in response to user actions or network responses. Proper state management ensures that your app's UI updates correctly when the state changes.
### Built-in State Management
React Native provides a built-in way to manage state using the `useState` hook for functional components and `this.setState` for class components. This method is ideal for simple state management within individual components.
**Example using `useState`:**
```javascript
import React, { useState } from 'react';
import { View, Text, Button } from 'react-native';
const CounterApp = () => {
const [count, setCount] = useState(0);
return (
<View>
<Text>{count}</Text>
<Button title="Increment" onPress={() => setCount(count + 1)} />
</View>
);
};
export default CounterApp;
```
### Context API
For managing state across multiple components, React Native offers the Context API. It allows you to share state without passing props down manually through every level of the component tree.
**Example using Context API:**
```javascript
import React, { createContext, useState, useContext } from 'react';
import { View, Text, Button } from 'react-native';
const CountContext = createContext();
const CountProvider = ({ children }) => {
const [count, setCount] = useState(0);
return (
<CountContext.Provider value={{ count, setCount }}>
{children}
</CountContext.Provider>
);
};
const Counter = () => {
const { count, setCount } = useContext(CountContext);
return (
<View>
<Text>{count}</Text>
<Button title="Increment" onPress={() => setCount(count + 1)} />
</View>
);
};
const App = () => (
<CountProvider>
<Counter />
</CountProvider>
);
export default App;
```
### Redux
Redux is a popular library for managing state in React and React Native applications. It provides a predictable state container and ensures that state changes are traceable and manageable. Redux is ideal for larger applications with complex state logic.
**Example using Redux:**
1. **Install Redux and React-Redux:**
```bash
npm install redux react-redux
```
2. **Create a Redux Store:**
```javascript
import { createStore } from 'redux';
const initialState = { count: 0 };
const reducer = (state = initialState, action) => {
switch (action.type) {
case 'INCREMENT':
return { ...state, count: state.count + 1 };
default:
return state;
}
};
const store = createStore(reducer);
```
3. **Create React Components and Connect to Redux:**
```javascript
import React from 'react';
import { Provider, useDispatch, useSelector } from 'react-redux';
import { View, Text, Button } from 'react-native';
import store from './store'; // Import your store
const Counter = () => {
const count = useSelector((state) => state.count);
const dispatch = useDispatch();
return (
<View>
<Text>{count}</Text>
<Button title="Increment" onPress={() => dispatch({ type: 'INCREMENT' })} />
</View>
);
};
const App = () => (
<Provider store={store}>
<Counter />
</Provider>
);
export default App;
```
### MobX
MobX is another state management library that uses observables to track state changes. It is known for its simplicity and flexibility, making it an excellent choice for developers who prefer a more straightforward approach than Redux.
**Example using MobX:**
1. **Install MobX and MobX-React:**
```bash
npm install mobx mobx-react
```
2. **Create a MobX Store:**
```javascript
import { observable, action } from 'mobx';
class CounterStore {
@observable count = 0;
@action increment = () => {
this.count += 1;
};
}
export default new CounterStore();
```
3. **Create React Components and Connect to MobX:**
```javascript
import React from 'react';
import { observer } from 'mobx-react';
import { View, Text, Button } from 'react-native';
import counterStore from './store'; // Import your store
const Counter = observer(() => (
<View>
<Text>{counterStore.count}</Text>
<Button title="Increment" onPress={counterStore.increment} />
</View>
));
const App = () => <Counter />;
export default App;
```
### Zustand
Zustand is a lightweight state management library that provides a more flexible and straightforward approach compared to Redux and MobX. It uses hooks for state management, making it very easy to integrate into React Native applications.
**Example using Zustand:**
1. **Install Zustand:**
```bash
npm install zustand
```
2. **Create a Zustand Store:**
```javascript
import create from 'zustand';
const useStore = create((set) => ({
count: 0,
increment: () => set((state) => ({ count: state.count + 1 })),
}));
export default useStore;
```
3. **Create React Components and Use Zustand:**
```javascript
import React from 'react';
import { View, Text, Button } from 'react-native';
import useStore from './store'; // Import your Zustand store
const Counter = () => {
const count = useStore((state) => state.count);
const increment = useStore((state) => state.increment);
return (
<View>
<Text>{count}</Text>
<Button title="Increment" onPress={increment} />
</View>
);
};
const App = () => <Counter />;
export default App;
```
### Valtio
Valtio is another lightweight state management library that uses proxies to manage state. It provides a simple and reactive way to manage state in your React Native applications.
**Example using Valtio:**
1. **Install Valtio:**
```bash
npm install valtio
```
2. **Create a Valtio Store:**
```javascript
import { proxy, useSnapshot } from 'valtio';
const state = proxy({ count: 0 });
const increment = () => {
state.count += 1;
};
export { state, increment };
```
3. **Create React Components and Use Valtio:**
```javascript
import React from 'react';
import { View, Text, Button } from 'react-native';
import { useSnapshot } from 'valtio';
import { state, increment } from './store'; // Import your Valtio store
const Counter = () => {
const snapshot = useSnapshot(state);
return (
<View>
<Text>{snapshot.count}</Text>
<Button title="Increment" onPress={increment} />
</View>
);
};
const App = () => <Counter />;
export default App;
```
### Conclusion
Choosing the right state management solution depends on the complexity and scale of your React Native application. For simple applications, the built-in state management and Context API are often sufficient. For larger applications with more complex state logic, Redux, MobX, Zustand, or Valtio can provide the necessary tools to manage state effectively.
By understanding and implementing the appropriate state management techniques, you can ensure your React Native application remains maintainable, scalable, and responsive to user interactions.
Valtio is my personal favourite for small or medium-sized apps.❤️
Manjot Singh,
Senior Mobile Engineer at Yara.com
| manjotdhiman |
1,897,103 | Differences of JPG and GIF | What Are the Differences Between JPG and GIF? JPG (or JPEG - Joint Photographic Experts... | 0 | 2024-06-22T14:49:24 | https://dev.to/msmith99994/differences-of-jpg-and-gif-4mo6 | ## What Are the Differences Between JPG and GIF?
JPG (or JPEG - Joint Photographic Experts Group) and GIF (Graphics Interchange Format) are two of the most commonly used image formats, each with its own set of characteristics suited for different applications.
### JPG
**- Compression:** JPG uses lossy compression, which reduces file size by discarding some image data. This can result in a loss of quality, especially at higher compression levels.
**- Color Depth:** Supports 24-bit color, displaying millions of colors, making it ideal for photographs and detailed images.
**- File Size:** Generally smaller due to lossy compression, which is beneficial for web use.
**- Transparency:** Does not support transparency.
**- Animation:** Does not support animation.
### GIF
**- Compression:** GIF uses lossless compression, ensuring no loss of image quality. However, it is limited to a palette of 256 colors, which can restrict its use for detailed images.
**- Color Depth:** Limited to 8-bit color, supporting up to 256 colors, making it less suitable for detailed images.
**- Transparency:** Supports binary transparency, meaning a pixel can be fully transparent or fully opaque.
**- Animation:** Supports animations, allowing multiple frames within a single file, ideal for simple animated graphics.
**- File Size:** Generally small, especially for simple graphics with limited colors.
## Where Are They Used?
### JPG
**- Digital Photography:** Standard format for digital cameras and smartphones due to its balance of quality and file size.
**- Web Design:** Widely used for photographs and complex images on websites because of its quick loading times.
**- Social Media:** Preferred for sharing images on social platforms due to its universal support and small file size.
**- Email and Document Sharing:** Frequently used in emails and documents for easy viewing and sharing.
### GIF
**- Web Graphics:** Ideal for simple graphics, icons, and logos with limited colors.
**- Animations:** Widely used for simple animations and short looping clips on websites and social media.
**- Emojis and Stickers:** Used in messaging apps for animated emojis and stickers.
**- Graphs and Diagrams:** Often used for simple graphics and charts that require clarity and small file sizes.
## Benefits and Drawbacks
### JPG
**Benefits:**
**- Small File Size:** Effective lossy compression reduces file sizes significantly.
**- Wide Compatibility:** Supported by almost all devices, browsers, and software.
**- High Color Depth:** Capable of displaying millions of colors, ideal for photographs.
**- Adjustable Quality:** Compression levels can be adjusted to balance quality and file size.
**Drawbacks:**
**- Lossy Compression:** Quality degrades with higher compression levels and repeated edits.
**- No Transparency:** Does not support transparent backgrounds.
**- Limited Editing Capability:** Cumulative compression losses make it less ideal for extensive editing.
**- No Animation Support:** Cannot handle animations within a single file.
## GIF
**Benefits:**
**- Small File Size:** Effective for simple graphics with limited colors.
**- Animation Support:** Allows for simple animations within a single file.
**- Wide Compatibility:** Supported by almost all browsers and devices.
**- Lossless Compression:** Maintains original image quality without any loss.
**Drawbacks:**
**- Limited Color Range:** Restricted to 256 colors, which is insufficient for detailed images.
**- Binary Transparency:** Does not support varying levels of transparency.
**- No Advanced Features:** Lacks support for complex color profiles and transparency levels.
## Is It Possible to Convert JPG to GIF
Converting [JPG to GIF](https://cloudinary.com/tools/jpg-to-gif) can be beneficial when you need animation support or smaller file sizes with limited colors. There are plenty of options and tools for converting these two formats.
## The Bottom Line
JPG and GIF are both essential image formats with distinct advantages and use cases. JPG is favored for its small file sizes, high color depth, and wide compatibility, making it ideal for digital photography and web use. GIF excels in supporting simple animations and graphics with limited colors, making it perfect for web graphics and animated elements.
Understanding the differences between JPG and GIF, and knowing how to convert between them, allows you to choose the best format for your specific needs. Whether you need the high color depth and compression efficiency of JPG or the animation capabilities and small file size of GIF, mastering these formats ensures you can handle any digital image requirement effectively.
| msmith99994 | |
1,897,100 | AWS Global Accelerator | 🚀 Exciting News! 🚀 I'm thrilled to announce that I've achieved AWS certification! 🎉 After months of... | 0 | 2024-06-22T14:46:44 | https://dev.to/vidhey071/aws-global-accelerator-1mei | aws | 🚀 Exciting News! 🚀
I'm thrilled to announce that I've achieved AWS certification! 🎉
After months of dedicated learning and hard work, I am now officially certified with this certificate. This journey has been incredibly rewarding, and I'm looking forward to leveraging this knowledge to drive innovation and efficiency in cloud computing.
A huge thank you to everyone who supported me along the way. Your encouragement and guidance meant the world to me.
Let's continue to push boundaries and explore new possibilities with AWS! 💡 | vidhey071 |
1,897,099 | Introduction to Amazon Polly | 🚀 Exciting News! 🚀 I am thrilled to announce that I have achieved my AWS certification! 🎉 After... | 0 | 2024-06-22T14:46:03 | https://dev.to/vidhey071/introduction-to-amazon-polly-hk7 | aws | 🚀 Exciting News! 🚀
I am thrilled to announce that I have achieved my AWS certification! 🎉 After months of hard work and dedication, I am now certified with this certificate. This accomplishment signifies my commitment to mastering AWS services and best practices, enhancing my skills in cloud computing and infrastructure management.
I am grateful for the support of my colleagues, mentors, and the invaluable resources provided by AWS. This journey has been incredibly rewarding, and I look forward to applying my knowledge to deliver innovative solutions and contribute effectively to our projects.
Thank you all for your encouragement and belief in my abilities. Let's continue to strive for excellence together! | vidhey071 |
1,897,098 | Optimizing Development: Insights into Effective System Design | As a full-stack developer, I've come to appreciate the profound impact that understanding system... | 0 | 2024-06-22T14:45:57 | https://dev.to/a_shokn/optimizing-development-insights-into-effective-system-design-5fc4 | webdev, systemdesign, typescript, beginners | As a full-stack developer, I've come to appreciate the profound impact that understanding system design can have on the success of any project. Whether you’re building web or mobile applications, having a solid grasp of system design can set you apart and significantly improve your ability to create robust, scalable solutions. In this blog, I’ll demystify system design, explore its origins, discuss key design patterns leading companies use, and provide simple examples to illustrate these concepts.
### What is System Design
System design defines the architecture, components, modules, interfaces, and data for a system to satisfy specified requirements. It involves a high-level understanding of how different parts of a system interact and how they can be organized to handle various tasks efficiently.
### The Origin of System Design
The term "system design" has been around for decades, evolving with the advancement of technology and the increasing complexity of systems. While there isn't a single person credited with coining the term, it has been influenced by pioneers in computer science and software engineering, such as Frederick P. Brooks and his seminal work "The Mythical Man-Month," which emphasizes the importance of design in software projects.
### Why System Design is Important for Developers
Understanding system design is crucial for several reasons:
Scalability: As user bases grow, systems need to handle increased loads without degrading performance.
Maintainability: Well-designed systems are easier to maintain and extend.
Efficiency: Proper design ensures that resources are used optimally, reducing costs.
Reliability: Systems designed with redundancy and fault tolerance in mind are more reliable.
Team Collaboration: A clear design allows team members to understand the system's structure and work together more effectively.
### Design Patterns Used by Companies
Reputed companies like Google, Facebook, and Amazon use various design patterns to build their systems. Here are a few key patterns:
Microservices Architecture: This pattern involves breaking down a large system into smaller, independent services that communicate through APIs. Each service handles a specific business function. Companies like Netflix and Amazon use this pattern to build scalable and maintainable systems.
Example: Imagine an online shopping platform. The platform can be broken down into microservices like user authentication, product catalog, shopping cart, and payment processing. Each service operates independently, allowing for easier updates and scaling.
Load Balancing: To handle high traffic, companies use load balancers to distribute incoming requests across multiple servers, ensuring no single server is overwhelmed.
Example: Think of a restaurant with multiple waiters. Instead of one waiter taking all the orders, the restaurant manager distributes customers evenly among the waiters, ensuring prompt service.
Caching: Caching involves storing frequently accessed data in a temporary storage location to reduce the time taken to retrieve data from the main database. Companies like Facebook use caching to speed up access to user profiles and posts.
Example: Consider a library where popular books are kept on a special shelf near the entrance. This way, readers can quickly find and borrow these books without searching the entire library.
Database Sharding: This technique splits a large database into smaller, more manageable pieces called shards. Each shard contains a subset of the data, which helps improve performance and scalability.
Example: Imagine splitting a massive phone book into smaller sections, each covering a specific region. When looking up a number, you only search the relevant section, saving time and effort.
Stay curious, keep learning, and happy coding!
| a_shokn |
1,896,934 | GalaxyBot: A Cosmic WhatsApp Chatbot with Laravel, Twilio, and Cloudflare AI | This is a submission for Twilio Challenge v24.06.12 What I Built I have created a... | 0 | 2024-06-22T14:38:44 | https://dev.to/snehalkadwe/galaxybot-a-cosmic-whatsapp-chatbot-with-laravel-twilio-and-cloudflare-ai-3oho | devchallenge, twiliochallenge, ai, twilio | *This is a submission for [Twilio Challenge v24.06.12](https://dev.to/challenges/twilio)*
## What I Built
I have created a GalaxyBot, an informative WhatsApp chatbot that delivers detailed information about stars and galaxies. The bot uses Laravel for the backend, Twilio for WhatsApp messaging, and Cloudflare's AI for generating responses.
- **User Interaction and processing:** Users send the bot queries about stars and galaxies.
- **AI Integration:** The bot passes the query to Cloudflare's AI model, which returns detailed information about the star or galaxy.
- **Response Delivery:** GalaxyBot sends the information back to the user's WhatsApp via Twilio.
## Twilio and AI
I have used **Twilio Messaging API** to set the communication channel for WhatsApp and the AI model `@cf/meta/llama-2-7b-chat-fp16` from **Cloudflare Workers AI** using REST API.
**1. Seamless Messaging:** Twilio's WhatsApp API allows to receive user messages and send responses seamlessly, providing a robust messaging platform.
**2. Dynamic Responses:** Using Cloudflare's AI, the bot generates dynamic and accurate information based on user queries. I am using Cloudflare Workers AI.
**3. Efficient Communication:** The integration of Twilio with AI ensures that users receive detailed and relevant information promptly, making the bot an effective educational tool.
**Demo**
This application is currently running in a sandbox environment. To test the application you can send a message `alphabet-theory` to the number `+14155238886` or scan the QR code from your mobile.
**Github Repo**
{% embed https://github.com/snehalkadwe/galaxy-info-chatbot %}
Kudos to the Dev team for organizing an amazing challenge.
| snehalkadwe |
1,897,094 | Become A Full Stack Developer in Lahore | Join Web Development trainings in Lahore and unlock the potential in the world of coding. Learn from... | 0 | 2024-06-22T14:37:37 | https://dev.to/shantrainings/become-a-full-stack-developer-in-lahore-1fpe | Join [Web Development trainings](https://shantrainings.com/web-development) in Lahore and unlock the potential in the world of coding. Learn from shan trainings and build your career today. If you are looking HTML and CSS in Web Development trainings in Lahore. Shan Trainings offering best courses programm. | shantrainings | |
1,897,093 | How Amazon SageMaker Can Help | 🚀 Exciting News! 🚀 I'm thrilled to announce that I've achieved AWS certification! 🎉 After months of... | 0 | 2024-06-22T14:36:56 | https://dev.to/vidhey071/how-amazon-sagemaker-can-help-44b1 | aws | 🚀 Exciting News! 🚀
I'm thrilled to announce that I've achieved AWS certification! 🎉
After months of dedicated learning and hard work, I am now officially certified with this certificate. This journey has been incredibly rewarding, and I'm looking forward to leveraging this knowledge to drive innovation and efficiency in cloud computing.
A huge thank you to everyone who supported me along the way. Your encouragement and guidance meant the world to me.
Let's continue to push boundaries and explore new possibilities with AWS! 💡 | vidhey071 |
1,897,092 | Amazon Direct Connect | 🚀 Exciting News! 🚀 I am thrilled to announce that I have achieved my AWS certification! 🎉 After... | 0 | 2024-06-22T14:36:14 | https://dev.to/vidhey071/amazon-direct-connect-3lh5 | aws | 🚀 Exciting News! 🚀
I am thrilled to announce that I have achieved my AWS certification! 🎉 After months of hard work and dedication, I am now certified with this certificate. This accomplishment signifies my commitment to mastering AWS services and best practices, enhancing my skills in cloud computing and infrastructure management.
I am grateful for the support of my colleagues, mentors, and the invaluable resources provided by AWS. This journey has been incredibly rewarding, and I look forward to applying my knowledge to deliver innovative solutions and contribute effectively to our projects.
Thank you all for your encouragement and belief in my abilities. Let's continue to strive for excellence together! | vidhey071 |
1,896,511 | JIN: A Light-Weight Hacking Tool Project | Today, I want to share my own simple cli application used for mapping URL, mapping open port of... | 0 | 2024-06-22T14:32:25 | https://dev.to/aliftech/jin-a-light-weight-hacking-tool-project-3hkc | cybersecurity, cli, python, programming | Today, I want to share my own simple cli application used for mapping URL, mapping open port of targeted website, and launching a DDoS attack. Disclaimer on, this project is made just for educational purpose, so I do not recommend you to use this project for unethical purpose.
## What is CLI ?
**CLI** stands for Command Line Interface is a way we interact with computer programs through text commands in a console or terminal. Instead of using graphical elements like windows or buttons, users type commands to perform tasks. CLIs is prevalent in programming, system administration, and various tech field because they offer powerful and efficient way to manage tasks and automate workflows.
## What is JIN ?
As I mention before, JIN is a simple CLI application designed for doing URL mapping, open port mapping, and launching a DDoS attack. This tool is made for education purpose and just to satisfy my curiosity. For further information, you can follow the link bellow.
[JIN Repository](https://github.com/aliftech/jin).
## Installation and Setup
clone the JIN project using the following command:
```bash
git clone https://github.com/aliftech/jin.git
```
After that, move to root project and create a virtual environment using the following command:
```bash
py -m venv env
```
```bash
.\env\Scripts\activate
```
After creating a virtual environment, the next step is installing all required dependencies using the following command:
```bash
pip install -r requirements.txt
```
Well, the JIN application is now ready to use.
## Install and Setup JIN Using Docker
Beside installing and setup JIN application using the previous way, there is one more simple installation method, that is running this application using docker. In order to do that, you only need to run the following command:
```bash
docker compose run jin
```
Then you can use your project now.
| aliftech |
1,897,081 | Getting Started with NLB | 🚀 Exciting News! 🚀 I'm thrilled to announce that I've achieved AWS certification! 🎉 After months of... | 0 | 2024-06-22T14:27:44 | https://dev.to/vidhey071/getting-started-with-nlb-1cn0 | aws | 🚀 Exciting News! 🚀
I'm thrilled to announce that I've achieved AWS certification! 🎉
After months of dedicated learning and hard work, I am now officially certified with this certificate. This journey has been incredibly rewarding, and I'm looking forward to leveraging this knowledge to drive innovation and efficiency in cloud computing.
A huge thank you to everyone who supported me along the way. Your encouragement and guidance meant the world to me.
Let's continue to push boundaries and explore new possibilities with AWS! 💡 | vidhey071 |
1,897,080 | Twitch Series | 🚀 Exciting News! 🚀 I am thrilled to announce that I have achieved my AWS certification! 🎉 After... | 0 | 2024-06-22T14:26:57 | https://dev.to/vidhey071/twitch-series-45m0 | aws | 🚀 Exciting News! 🚀
I am thrilled to announce that I have achieved my AWS certification! 🎉 After months of hard work and dedication, I am now certified with this certificate. This accomplishment signifies my commitment to mastering AWS services and best practices, enhancing my skills in cloud computing and infrastructure management.
I am grateful for the support of my colleagues, mentors, and the invaluable resources provided by AWS. This journey has been incredibly rewarding, and I look forward to applying my knowledge to deliver innovative solutions and contribute effectively to our projects.
Thank you all for your encouragement and belief in my abilities. Let's continue to strive for excellence together! | vidhey071 |
1,897,067 | UNDERSTANDING PYTHON CODE STRUCTURE | Code Structure This is the arrangement of code in a programming language. it encompasses the use of... | 0 | 2024-06-22T14:26:23 | https://dev.to/davidbosah/understanding-python-code-structure-1pkg | beginners, programming, python, tutorial |
**Code Structure**
This is the arrangement of code in a programming language. it encompasses the use of formatting techniques like whitespace and indentation. The goal of a good structure is reliability and maintainability.
**Python code Structures**
There are various parameters that are used in describing the Python language. There are basic ones that you must grasp. Let's look at some of them:
Comments:
These are used to make the code easy to understand. They start with "#"
Variables:
They are used to store data or values in your code.
Function:
They are used to exercise a certain function once called. They are either built in function or user defined function.
Data Types
Python Supports lots of built in data types including strings and integers.
Operators:
They are used to perform different operations on data and variables.
**Let's Apply these Structures**:
```py
#This right here is a comment
#Defining Variables
a=10
y="happy"
#Defining Arithmetic operation
answer= a+8
#Now for functions
#Examples of built in functions
Print()
Input()
#For user defined functions
Def Applaud (name)
Print("congratulations + name + !")
#Using the function
Applaud ("Meghan")
```
| davidbosah |
1,897,079 | Demystifying Web Components | Components are individual pieces of code which can be used in different contexts; they often... | 24,065 | 2024-06-22T14:24:28 | https://jamesiv.es/blog/frontend/javascript/2024/03/26/demystifying-web-components | webdev, webcomponents, javascript, beginners | Components are individual pieces of code which can be used in different contexts; they often represent a reusable piece of a design, such as a button or badge, and sometimes even as complex as more prominent elements like carousels and lightboxes. One of the many goals of a component is to bring consistency and cohesion, preventing multiple one-off implementations of the same thing across a codebase or several codebases. Components come in many flavours. For instance, they can be written in a framework like [React](https://react.dev/), [Angular](https://angular.io/), or just [plain CSS](https://developer.mozilla.org/en-US/docs/Web/CSS). These are all great options, but these days, I've gravitated more towards [Web Components](https://developer.mozilla.org/en-US/docs/Web/API/Web_components).
## But Why Web Components?
A Web Component is a reusable custom HTML element that encapsulates its functionality and styling; they are built using a set of web platform APIs that are part of the HTML and DOM specifications, including [Custom Elements](https://developer.mozilla.org/en-US/docs/Web/API/Web_components/Using_custom_elements), [Shadow DOM](https://developer.mozilla.org/en-US/docs/Web/API/Web_components/Using_shadow_DOM), and [HTML Templates](https://developer.mozilla.org/en-US/docs/Web/API/Web_components/Using_templates_and_slots). Web components can be used in any JavaScript framework or library or with plain HTML and JavaScript, making them highly [interoperable](https://dictionary.cambridge.org/us/dictionary/english/interoperable).
```html
<daily-greeting></daily-greeting>
```
Consider Web Components in scenarios where you maintain multiple applications, especially if you have an active design system with a component library. Maintaining a component library written in a specific framework can often result in future applications being built in that same framework, as it's easier to integrate with your design system, even if that framework isn't the right choice for the project. Alternatively, suppose you're creating a new design system with existing legacy applications. In that case, the technology may already be all over the place, making Web Components an attractive choice.
> Several companies have adopted Web Components already, most notably YouTube, GitHub, Adobe, and Alaska Airlines. All of these companies have been around for a long time and have a lot of applications they maintain.
There are more reasons besides interoperability, though. One of the big ones is the Shadow DOM. When used, components placed on a page become shielded from exterior factors, meaning external stylesheets and general document queries cannot mutate your components. This level of protection can be great for a design system, as an element will always look the same way no matter how and where you use it. If you need to support some degree of customization, you can leverage [CSS variables](https://developer.mozilla.org/en-US/docs/Web/CSS/Using_CSS_custom_properties) as, by nature, they pierce the Shadow DOM. [You can also use the `part` pseudo-element](https://developer.mozilla.org/en-US/docs/Web/CSS/::part) to allow external CSS to target specific things.
```css
daily-greeting::part(message) {
color: #333;
}
daily-greeting {
--message-color: #333;
}
```
Additionally, the Shadow DOM provides the ability to build compositional components with the help of [slots](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/slot). Using these, you can provide an API for consumers to slot their elements into particular parts of a component. Slots are helpful as they allow for customization without being too restrictive. For example, suppose you want to support a header by providing it via a slot instead of an attribute. In that case, you can allow consumers to give a header tag relevant to where the component appears on their page to keep their DOM structure in a logical order. They also allow you to slot whole other components into one another, enabling you to build smaller atomic pieces that form more significant components and patterns when pieced together.
```html
<section>
<h1>My Page</h1>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
<daily-greeting>
<h2 slot="header">Hello, world!</h2>
<daily-icon slot="icon" icon="thumbs"><daily-icon>
</daily-greeting>
</section>
```
Ultimately, adopting Web Components depends on your current and future scenarios. It's easy to become vendor-locked, and Web Components could be a way to avoid that.
## Building a Web Component
So, how are these built? You'd be wrong to expect them to be overly complex and niche. Here's an example of a basic component that uses the `connectedCallback` lifecycle to show a greeting.
```javascript
class DailyGreeting extends HTMLElement {
connectedCallback() {
this.render()
}
render() {
let date = new Date()
let currentHour = date.getHours()
let greeting = ''
if (currentHour < 12) {
greeting = 'Good morning!'
} else if (currentHour < 18) {
greeting = 'Good afternoon!'
} else {
greeting = 'Good evening!'
}
this.shadowRoot.innerHTML = `
<div part="message">
${greeting}
</div>
`
}
}
window.customElements.define('daily-greeting', DailyGreeting)
```
We can easily support slots by adding a `slot` element. In the following example, I've added a default slot to a component which allows you to insert content to create a scrollable list. The following example includes more than slots; it covers several concepts, including attributes.
```javascript
class ScrollSnapCarousel extends HTMLElement {
static get observedAttributes() {
return ['alignment']
}
constructor() {
super()
this.shadow = this.attachShadow({ mode: 'open' })
this.alignment = 'start';
this.scrollToNextPage = this.scrollToNextPage.bind(this)
this.scrollToPreviousPage = this.scrollToPreviousPage.bind(this)
}
attributeChangedCallback(name, oldValue, newValue) {
if (name === 'alignment') {
this.alignment = newValue
}
}
connectedCallback() {
this.render()
this.gallery = this.shadowRoot.querySelector('#paginated-gallery')
this.galleryScroller = this.gallery.querySelector('.gallery-scroller')
this.calculateGalleryItemSize()
this.gallery
.querySelector('button.next')
.addEventListener('click', this.scrollToNextPage)
this.gallery
.querySelector('button.previous')
.addEventListener('click', this.scrollToPreviousPage)
window.addEventListener('resize', this.calculateGalleryItemSize)
}
disconnectedCallback() {
window.removeEventListener('resize', this.calculateGalleryItemSize)
}
calculateGalleryItemSize() {
const slotElement = this.galleryScroller.querySelector('slot')
const nodes = slotElement.assignedNodes({ flatten: true })
const firstSlottedElement = nodes.find(
(node) => node.nodeType === Node.ELEMENT_NODE,
)
this.galleryItemSize = firstSlottedElement.clientWidth
}
scrollToPreviousPage() {
this.galleryScroller.scrollBy(-this.galleryItemSize, 0)
}
scrollToNextPage() {
this.galleryScroller.scrollBy(this.galleryItemSize, 0)
}
render() {
this.shadowRoot.innerHTML = `
<style>
</style>
<div id="paginated-gallery" class="gallery">
<button class="previous" aria-label="Previous"></button>
<button class="next" aria-label="Next" ></button>
<div class="gallery-scroller">
<slot></slot>
</div>
</div>
`
}
}
window.customElements.define('scroll-snap-carousel', ScrollSnapCarousel)
```
You can project content into specific areas by giving the slot a name. For example, if we wanted to add some disclaimer text beneath the carousel, we could do so by adding another slot for it with the name `disclaimer`.
```javascript
render() {
this.shadowRoot.innerHTML = `
<style>
</style>
<div id="paginated-gallery" class="gallery">
<button class="previous" aria-label="Previous"></button>
<button class="next" aria-label="Next" ></button>
<div class="gallery-scroller">
<slot></slot>
</div>
</div>
<slot name="disclaimer"></slot>
`
}
```
With the custom element registered, all you'd need to do is place the following in the HTML to use the component.
```html
<scroll-snap-carousel alignment="start">
<iframe src="https://www.youtube.com/embed/3ZTvsUeQkOM?si=iNSnBcZRKWsMUB2e" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
<iframe src="https://www.youtube.com/embed/7Dr5LW9xnSs?si=aLyux8R2QGk61XwU" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
<iframe src="https://www.youtube.com/embed/31lbp1dolAI?si=B1SYEzLmlZ8QN3pG" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
<iframe src="https://www.youtube.com/embed/onthvMAIpUI?si=XZK9y1OkfAhMJUFY" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
<iframe src="https://www.youtube.com/embed/Ij-1kXYKD3c?si=ha_b0VuYevv-6q-V" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
<iframe src="https://www.youtube.com/embed/RFdLLDmTTk8?si=1RVxxa3Hw-nL8ph8" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
<span slot="disclaimer">Videos by <a href="">RayRay</a></span>
</scroll-snap-carousel>
```
This is what our component looks like. [You can test it on Codepen, too, if you'd like to mess around with the API and get a more in-depth explanation of what all the methods do](https://codepen.io/jamesives/pen/WNWOojO). If you have never encountered a Web Component before, especially one that utilizes the Shadow DOM, [open up your browser debugger](https://developer.chrome.com/docs/devtools/overview) to inspect it!
{% codepen https://codepen.io/jamesives/pen/WNWOojO %}
### The Shadow DOM Is Optional
You don't need to use the Shadow DOM; it's optional. Not using the Shadow DOM could be a good choice if you intend to provide smaller components with the expectation that others will apply additional styling or logic and don't want to offer part selectors or CSS variables for everything. However, removing the Shadow DOM also eliminates the ability to slot content, which is a significant loss and could make building specific components that rely on composition more challenging.
Using the previous example, I worked around the lack of slots by manipulating the tree with `document.createDocumentFragment` and appending child items in the correct spot after the component connects. It could be better, but it does work. As with anything, use your best judgment based on your needs to determine whether you should leverage the Shadow DOM. It can be more of a hindrance not to use it if you have a sound system for supporting variables as you lose the encapsulation benefits.
```javascript
class ScrollSnapCarousel extends HTMLElement {
static get observedAttributes() {
return ['alignment']
}
constructor() {
super()
this.alignment = 'start'
this.scrollToNextPage = this.scrollToNextPage.bind(this)
this.scrollToPreviousPage = this.scrollToPreviousPage.bind(this)
this.calculateGalleryItemSize = this.calculateGalleryItemSize.bind(this)
this.ingestChildren = this.ingestChildren.bind(this)
}
attributeChangedCallback(name, oldValue, newValue) {
if (name === 'alignment') {
this.alignment = newValue
}
}
connectedCallback() {
this.ingestChildren()
this.render()
this.gallery = this.querySelector('#paginated-gallery')
this.galleryScroller = this.gallery.querySelector('.gallery-scroller')
this.galleryScroller.appendChild(this.fragment)
this.gallery
.querySelector('button.next')
.addEventListener('click', this.scrollToNextPage)
this.gallery
.querySelector('button.previous')
.addEventListener('click', this.scrollToPreviousPage)
this.calculateGalleryItemSize()
window.addEventListener('resize', this.calculateGalleryItemSize)
}
disconnectedCallback() {
window.removeEventListener('resize', this.calculateGalleryItemSize)
}
ingestChildren() {
this.fragment = document.createDocumentFragment()
Array.from(this.children).forEach((child) => {
this.fragment.appendChild(child)
})
}
calculateGalleryItemSize() {
const nodes = Array.from(this.galleryScroller.children)
const firstElement = nodes.find(
(node) => node.nodeType === Node.ELEMENT_NODE,
)
this.galleryItemSize = firstElement.clientWidth
}
scrollToPreviousPage() {
this.galleryScroller.scrollBy(-this.galleryItemSize, 0)
}
scrollToNextPage() {
this.galleryScroller.scrollBy(this.galleryItemSize, 0)
}
render() {
this.innerHTML = `
<style>
</style>
<div id="paginated-gallery" class="gallery">
<div class="gallery-scroller"></div>
<button class="previous" aria-label="Previous"></button>
<button class="next" aria-label="Next" ></button>
</div>
`
}
}
window.customElements.define('scroll-snap-carousel', ScrollSnapCarousel)
```
If you want to try it out, [the example above is available on Codepen](https://codepen.io/jamesives/pen/jORwKQZ). Like the previous example, [open your browser debugger to see how it's constructed](https://developer.chrome.com/docs/devtools/overview), and you'll notice the lack of shadow root in the component tree.
{% codepen https://codepen.io/jamesives/pen/jORwKQZ %}
[A very active thread on GitHub discusses the concept of a Shadow DOM that supports a stylable root](https://github.com/WICG/webcomponents/issues/909). Still, it's in the discussion phase, so it will be long before this manifests into something usable.
### Consider a Framework
Consider adopting something like [Lit](https://lit.dev/) or [Stencil](https://stenciljs.com/) to build Web Components. These frameworks provide standard utilities for working with Web Components and handle everyday tasks such as change detection, server-side rendering, localization, etc. I've personally worked with Lit and find it helpful for preventing common mistakes and pitfalls. Additionally, they provide a series of best practices for authoring components, which I often refer to. [Something Stencil provides which is unique is a polyfill for `slot` for usage in non-Shadow DOM components](https://ionic.io/blog/enhanced-support-for-slots-outside-of-shadow-dom), which may be attractive to some.
Here's an example of a basic Lit element with TypeScript support. It's similar to my previous examples and ultimately results in something similar through class extensions.
```typescript
import {html, css, LitElement} from 'lit';
import {customElement, property} from 'lit/decorators.js';
@customElement('simple-greeting')
export class SimpleGreeting extends LitElement {
static styles = css`p { color: blue }`;
@property()
name = 'Somebody';
render() {
return html`<p>Hello, ${this.name}!</p>`;
}
}
```
The philosophy of these frameworks is similar to that of any other: they help you move faster. With these, you get all the benefits of using Web Components without writing lots of boilerplates every time you write a component.
### General Tips
I've learned a lot after working with Web Components for a while. Here's a general list of things I've picked up.
* <b>Be careful with inheritance in cases where a component doesn't define its own DOM tree and instead renders a pre-configured version of another.</b> If you have components that follow this pattern, you run the risk of exploding your applications with additional DOM nodes, especially if you forward slots. Consider using a class extension instead, or reconsider if a new component is necessary.
* <b>Document your components.</b> Tooling is available to [analyze JSDoc comments and produce artefacts from the output](https://custom-elements-manifest.open-wc.org/analyzer/getting-started/), such as README files. [An excellent add-on for Storybook will take that output and automatically generate controls for your component API](https://github.com/break-stuff/wc-storybook-helpers).
* <b>Use a linter and write unit tests.</b> Web Components have a habit of silencing errors, which can be frustrating to track down. The more tooling you add around them, the better your developer experience. [Lit for example provides a linter that can catch common mistakes](https://lit.dev/docs/v1/lit-html/tools/#linting).
* <b>Keep tabs on the industry.</b> Web components are still evolving, and some things are constantly being discussed or considered. Get involved in the conversation!
> You'll make mistakes, especially if it's your first time working with Web Components. While they are similar to working with other frameworks, they have their unique quirks that aren't always obvious at first.
## Conclusion
Overall, I really enjoy working with Web Components. While some have given them a bad rap, the technology is progressing in a favourable way, and many teams are starting to seriously consider them. They are the backbone to the design system I work on and have been a great way to ensure consistency across our applications.
| jamesives |
1,897,074 | Introduction to Forex Trading Pairs | Forex trading, also known as foreign exchange trading or currency trading, is the act of buying and... | 0 | 2024-06-22T14:19:56 | https://dev.to/ukwueze_frankfx/introduction-to-forex-trading-pairs-3dac |
Forex trading, also known as foreign exchange trading or currency trading, is the act of buying and selling currencies with the aim of making a profit. Central to this market are trading pairs, which are the foundation of all forex transactions. Understanding trading pairs is crucial for anyone looking to succeed in forex trading.
#### Explanation of What Trading Pairs Are
In forex trading, currencies are traded in pairs. This means that when you trade, you are simultaneously buying one currency and selling another. Each currency pair represents the exchange rate between two currencies. For example, in the EUR/USD pair, the first currency (EUR) is the base currency, and the second currency (USD) is the quote currency. The value of the pair indicates how much of the quote currency is needed to purchase one unit of the base currency.
[CLICK HERE TO OPEN TRADING ACCOUNT
](https://one.exnesstrack.net/a/ctauzaa2ge)
For instance, if the EUR/USD pair is quoted at 1.2000, it means that 1 Euro is equivalent to 1.20 US Dollars. If the exchange rate rises to 1.2500, the Euro has strengthened against the Dollar, meaning it now takes 1.25 US Dollars to buy 1 Euro.
#### Basic Concept of Currency Pairs in Forex Trading
Forex pairs can be broadly categorized into three groups:
1. **Major Pairs**: These pairs include the most traded currencies globally, typically featuring the US Dollar (USD) as one half of the pair. Examples include EUR/USD, GBP/USD, and USD/JPY. Major pairs are known for their high liquidity and lower spreads.
2. **Minor Pairs**: These pairs do not include the US Dollar but consist of other major currencies. Examples are EUR/GBP, AUD/JPY, and GBP/CAD. Minors are less liquid than majors and can have higher spreads.
3. **Exotic Pairs**: These pairs involve one major currency and one currency from an emerging or smaller economy, such as USD/TRY (US Dollar/Turkish Lira) or EUR/SGD (Euro/Singapore Dollar). Exotics can be more volatile and have higher spreads due to lower liquidity.
#### Importance of Choosing the Right Pairs for Trading Success
Choosing the right currency pairs to trade is a critical decision that can significantly impact your trading success. Different pairs offer different trading conditions, such as varying levels of volatility, liquidity, and spread costs. Here’s why selecting the appropriate pairs is important:
1. **Volatility**: Some currency pairs, like exotic pairs, are more volatile than others. Higher volatility can mean larger price swings and more trading opportunities, but it also means higher risk. Traders need to choose pairs that match their risk tolerance and trading style.
[
CLICK HERE TO OPEN TRADING ACCOUNT](https://one.exnesstrack.net/a/ctauzaa2ge)
2. **Liquidity**: Major pairs are highly liquid, meaning they are easier to buy and sell without causing significant price changes. High liquidity ensures that traders can enter and exit positions with minimal slippage. For day traders and scalpers, trading pairs with high liquidity is often preferable.
3. **Spread Costs**: The spread is the difference between the bid and ask price of a currency pair. Lower spreads reduce trading costs, which is particularly important for high-frequency traders. Major pairs typically have lower spreads compared to minor and exotic pairs.
#### How Selecting Appropriate Pairs Can Influence Trading Outcomes
The choice of currency pairs can greatly influence your trading outcomes in several ways:
1. **Profit Potential**: Different pairs offer varying levels of profit potential. While major pairs may provide steadier, more predictable movements, exotic pairs might offer greater profit opportunities due to their higher volatility.
2. **Risk Management**: Selecting pairs that align with your risk management strategy is essential. Trading highly volatile pairs without proper risk management can lead to significant losses. Conversely, trading more stable pairs can help in managing risk effectively.
3. **Market Analysis**: Some pairs are more influenced by specific economic events or geopolitical developments. Understanding the factors that impact your chosen pairs allows for better market analysis and more informed trading decisions.
4. **Trading Strategy Compatibility**: Certain pairs may be more suitable for specific trading strategies. For example, pairs with high volatility are ideal for breakout strategies, while more stable pairs might be better for trend-following strategies.
[
CLICK HERE TO CREATE TRADING ACCOUNT](https://one.exnesstrack.net/a/ctauzaa2ge)
In conclusion, understanding and choosing the right forex trading pairs is fundamental to your success as a forex trader. By carefully selecting pairs that align with your trading style, risk tolerance, and market analysis, you can enhance your trading outcomes and achieve greater profitability in the dynamic world of forex trading. | ukwueze_frankfx | |
1,897,073 | Enhancing Your Coding Skills: A Comprehensive Guide | Enhancing Your Coding Skills: A Comprehensive Guide Programming is an ever-evolving field that... | 0 | 2024-06-22T14:19:54 | https://dev.to/cottolight_14c3b6c6922677/enhancing-your-coding-skills-a-comprehensive-guide-532p | Enhancing Your Coding Skills: A Comprehensive Guide
Programming is an ever-evolving field that requires constant learning and adaptation. Whether you are a novice coder or an experienced developer, staying updated with the latest trends, tools, and best practices is crucial. This blog blends insights from our experience and the rich content available on platforms like Dev.to to help you enhance your coding skills and stay ahead in the tech industry.
The Importance of Continuous Learning
In programming, continuous learning is essential. Technology changes rapidly, and what’s cutting-edge today might be obsolete tomorrow. By committing to ongoing education, you can keep your skills sharp and stay relevant in the industry.
Key Areas to Focus On
Fundamentals
Data Structures and Algorithms: Mastering these basics is crucial for writing efficient code. Platforms like LeetCode and HackerRank offer valuable practice problems.
Programming Languages: While it’s beneficial to know multiple languages, specializing in one or two can make you more proficient. Common languages include Python, JavaScript, Java, and C++.
Version Control
Git and GitHub: Understanding version control is essential for collaborating on projects and managing code changes. GitHub also provides a platform for showcasing your work.
Development Tools
Integrated Development Environments (IDEs): Tools like VS Code, IntelliJ IDEA, and PyCharm can significantly enhance productivity.
Debugging Tools: Learning to use debugging tools effectively can save time and help you understand and fix issues more efficiently.
Testing
Unit Testing: Writing tests for your code ensures it works as expected and reduces the likelihood of bugs. Frameworks like JUnit for Java and pytest for Python are popular choices.
Test-Driven Development (TDD): This methodology involves writing tests before writing the actual code, ensuring that your development process is focused and reliable.
Embracing New Technologies
Staying updated with the latest technologies and frameworks is crucial. Here are some current trends in the programming world:
Artificial Intelligence and Machine Learning
AI and ML: These fields are growing rapidly, with applications in various industries. Familiarizing yourself with tools like TensorFlow and PyTorch can open new career opportunities.
Web Development Frameworks
React, Angular, and Vue.js: These JavaScript frameworks are popular for building modern web applications. Each has its strengths, and learning one or more can enhance your web development skills.
DevOps
CI/CD Pipelines: Continuous Integration and Continuous Deployment are practices that automate the testing and deployment of code, making the development process more efficient. Tools like Jenkins, Travis CI, and GitLab CI are widely used.
Learning Resources
Online Courses and Tutorials
Platforms like Coursera, Udemy, and freeCodeCamp offer comprehensive courses on various programming topics.
Dev.to: This community-driven platform offers articles, tutorials, and discussions on a wide range of programming topics. It's a great place to learn from and connect with other developers.
Books
Classics like "Clean Code" by Robert C. Martin and "You Don’t Know JS" by Kyle Simpson are invaluable resources for understanding best practices and advanced concepts.
Communities and Forums
Engaging with communities such as Stack Overflow, Reddit, and Dev.to can provide support, feedback, and networking opportunities.
Building Projects
Practical experience is one of the best ways to learn. Building your own projects allows you to apply what you’ve learned, solve real-world problems, and showcase your skills to potential employers.
Open Source Contributions
Contributing to open-source projects on platforms like GitHub can provide valuable experience and help you learn from more experienced developers.
Personal Projects
Creating your own projects, whether it’s a simple web app or a complex algorithm, helps solidify your knowledge and demonstrates your abilities to others.
Best Practices
Code Reviews
Participating in code reviews can improve your coding skills by learning from others and receiving constructive feedback.
Documentation
Writing clear and concise documentation makes your code more understandable and maintainable. It’s an essential practice, especially when working in teams.
Refactoring
Regularly refactoring your code to improve its structure and readability can lead to better performance and maintainability.
Conclusion
Enhancing your coding skills is a continuous journey that involves learning, practicing, and staying updated with the latest trends and technologies. By focusing on the fundamentals, embracing new technologies, utilizing various learning resources, and building projects, you can significantly improve your programming abilities. For a versatile and comfortable option in your development setup, consider integrating new tools and practices that enhance your workflow and productivity.
For more insights and articles on programming, visit Dev.to.
Product: [فانلة كت رجالي](https://cottolight.com/products/cut-o-lycra) | cottolight_14c3b6c6922677 | |
1,897,071 | Basics of DNS | 🚀 Exciting News! 🚀 I'm thrilled to announce that I've achieved AWS certification! 🎉 After months of... | 0 | 2024-06-22T14:19:02 | https://dev.to/vidhey071/basics-of-dns-181m | aws | 🚀 Exciting News! 🚀
I'm thrilled to announce that I've achieved AWS certification! 🎉
After months of dedicated learning and hard work, I am now officially certified with this certificate. This journey has been incredibly rewarding, and I'm looking forward to leveraging this knowledge to drive innovation and efficiency in cloud computing.
A huge thank you to everyone who supported me along the way. Your encouragement and guidance meant the world to me.
Let's continue to push boundaries and explore new possibilities with AWS! 💡 | vidhey071 |
1,897,069 | Amazon Route 53 - Domains | 🚀 Exciting News! 🚀 I am thrilled to announce that I have achieved my AWS certification! 🎉 After... | 0 | 2024-06-22T14:18:17 | https://dev.to/vidhey071/amazon-route-53-domains-2a1h | aws | 🚀 Exciting News! 🚀
I am thrilled to announce that I have achieved my AWS certification! 🎉 After months of hard work and dedication, I am now certified with this certificate. This accomplishment signifies my commitment to mastering AWS services and best practices, enhancing my skills in cloud computing and infrastructure management.
I am grateful for the support of my colleagues, mentors, and the invaluable resources provided by AWS. This journey has been incredibly rewarding, and I look forward to applying my knowledge to deliver innovative solutions and contribute effectively to our projects.
Thank you all for your encouragement and belief in my abilities. Let's continue to strive for excellence together! | vidhey071 |
1,285,729 | Setting Up Nginx with Certbot for HTTPS on Your Web Application | Securing your web application with HTTPS is crucial for protecting data integrity and privacy. This... | 0 | 2024-06-22T14:18:05 | https://dev.to/yousufbasir/setting-up-nginx-with-certbot-for-https-on-your-web-application-n1i | nginx, certbot, ssl, webdev | Securing your web application with HTTPS is crucial for protecting data integrity and privacy. This guide will walk you through the steps to set up Nginx as a reverse proxy and use Certbot to obtain a free SSL certificate from Let's Encrypt.
### Prerequisites
Before you begin, ensure you have the following:
1. A domain name pointing to your server's IP address.
2. A server running Ubuntu (or any other Linux distribution).
3. Nginx installed on your server.
### Step 1: Configure Nginx
First, we need to set up Nginx to proxy requests to our web application. Open your Nginx configuration file or create a new one for your domain:
```bash
sudo nano /etc/nginx/sites-available/my.website.com
```
Add the following configuration:
```nginx
server {
listen 80;
listen [::]:80;
server_name my.website.com www.my.website.com;
location / {
proxy_pass http://localhost:5173;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}
```
This configuration listens for HTTP requests on port 80 and proxies them to your web application running on `localhost:5173`.
### Step 2: Enable the Nginx Configuration
Create a symbolic link to enable the configuration:
```bash
sudo ln -s /etc/nginx/sites-available/my.website.com /etc/nginx/sites-enabled/
```
Test the Nginx configuration for syntax errors:
```bash
sudo nginx -t
```
If the test is successful, reload Nginx to apply the changes:
```bash
sudo systemctl reload nginx
```
### Step 3: Install Certbot
Certbot is a tool that automates the process of obtaining and renewing SSL certificates from Let's Encrypt. Install Certbot and the Nginx plugin:
```bash
sudo apt update
sudo apt install certbot python3-certbot-nginx
```
### Step 4: Obtain an SSL Certificate
Run Certbot to obtain an SSL certificate and configure Nginx to use it:
```bash
sudo certbot --nginx
```
Follow the interactive prompts. Certbot will:
1. Detect your Nginx configuration.
2. Allow you to select the domain you want to secure.
3. Automatically obtain and install the SSL certificate.
4. Modify your Nginx configuration to redirect HTTP traffic to HTTPS.
Certbot will update your Nginx configuration to something like this:
```nginx
server {
listen 80;
listen [::]:80;
server_name my.website.com www.my.website.com;
return 301 https://$host$request_uri;
}
server {
listen 443 ssl;
listen [::]:443 ssl;
server_name my.website.com www.my.website.com;
ssl_certificate /etc/letsencrypt/live/my.website.com/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/my.website.com/privkey.pem;
include /etc/letsencrypt/options-ssl-nginx.conf;
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
location / {
proxy_pass http://localhost:5173;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}
```
### Step 5: Verify HTTPS
After Certbot completes, verify that your site is accessible via HTTPS by navigating to your website url (e.g. `https://my.website.com` ) in your browser.
### Conclusion
You have successfully set up Nginx as a reverse proxy for your web application and secured it with an SSL certificate from Let's Encrypt using Certbot. This setup not only secures your web application but also improves its trustworthiness and SEO ranking.
For further reading and additional configurations, you may refer to the following resources:
- [Deploy Next.js App With Nginx, Let's Encrypt, and PM2](https://jasonvan.ca/posts/deploy-next-js-app-with-nginx-let-s-encrypt-and-pm2)
- [Certbot Instructions for Nginx on Ubuntu](https://certbot.eff.org/instructions?ws=nginx&os=ubuntufocal) | yousufbasir |
1,897,051 | AWS : IAM : Root Account | This article on DEV Community explains AWS Identity and Access Management (IAM) and its capabilities... | 0 | 2024-06-22T14:17:29 | https://dev.to/oladipupoabeeb/aws-iam-root-account-2mb4 | aws, cloud, terraform, webdev | This article on DEV Community explains AWS Identity and Access Management (IAM) and its capabilities for managing users, groups, and permissions within AWS. It highlights how IAM allows creating users with unique credentials and assigning permissions through policies. The article includes examples of using Terraform to automate the creation of IAM users, access keys, and policies.
Link:[WHAT IS IAM](https://dev.to/oladipupoabeeb/aws-identity-access-management-iam-16d8)
IAM is a service that allows you to create and manage users and groups, and to assign permissions that control access to AWS resources.
**The Root Account** is the initial account created when you sign up for AWS. It has full administrative access to all AWS services and resources in the account. The root account is identified by the email address used during account creation.
**Important:** The root account should only be used for tasks requiring unique permissions. For everyday administrative tasks, create IAM users with the necessary permissions.
## How to Secure the Root User
## 1. Enable Multi-Factor Authentication (MFA)
· Log in to the AWS Management Console using your root account.
· Navigate to the IAM service.
· In the left-hand navigation pane, click on Dashboard.
· Under the Activate MFA on your root account section, click on Manage MFA.
· Follow the instructions to set up MFA for your root account.
## 2. Create an admin group and assign the appropriate permission
**_Step-by-Step Guide to Creating an "Admins" Group in AWS IAM_**
**Log in to AWS Management Console:**
Open your web browser and go to the AWS Management Console. Log in with your credentials.
**Navigate to IAM:**
In the AWS Management Console, type "IAM" in the search bar and select IAM to open the Identity and Access Management dashboard.
**Create a New Group:**
In the left-hand navigation pane, click on User groups.
Click the Create group button.
**Set Group Name:**
On the Create user group page, enter a name for your group. For example, "Admins".
Click Next to proceed.
**Attach Permissions Policies:**
On the Attach permissions policies page, you need to add the policies that will define the permissions for the group.
Scroll through the list or use the search bar to find the policy named AdministratorAccess.
Check the box next to AdministratorAccess. This policy provides full access to AWS services and resources.
**Review and Create the Group:**
Review the group details, ensuring that the correct policy is attached.
Click Create Group.
## 3. Create a User account for admins
- Navigate to the IAM service.
- In the left-hand navigation pane, click on Users and then Create User.
- Enter a username (e.g., UserAdmin).
- Select Programmatic access and AWS Management Console access.
- Set a custom password or allow the user to create one at first sign-in.
- Click Next: Permissions.
- In the policy list, search for AdministratorAccess.
- Check the box next to AdministratorAccess and click Create group.
- Ensure the new group is selected and click Next: Tags.
- Add any tags if necessary and click Next: Review.
- Review the details and click Create user.
## 4. Add users to the admin group
- Navigate to User Groups, and click on the group name to add the user.
- Scroll down and Click on Add Users.
- Select the User to be added to the Admin group and the users will be added successfully to the group operating under the policies in that group.
By following these steps and best practices, you can ensure your AWS account is securely configured and that administrative access is managed appropriately.
| oladipupoabeeb |
1,897,068 | Difference Between ++a And a++ In JavaScript? | The ++ is responsible of the increment of the number value by 1 . But have you wondered what is the... | 0 | 2024-06-22T14:15:47 | https://dev.to/yns666/difference-between-a-and-a-in-javascript-21n2 | javascript, webdev, beginners, programming | The **++** is responsible of the increment of the number value by 1 . But have you wondered what is the difference between putting it before or after?
- **++a** : returns the value after the increment.
- **a++** : returns the value before the increment.
Let's take an example:
`let a=0;
a++;
++a;
`
the output will be:
`output->0
1 `
| yns666 |
1,897,064 | HTML and CSS and JS icons (css pure) | Check out this Pen I made! | 0 | 2024-06-22T14:08:17 | https://dev.to/tidycoder/html-and-css-and-js-icons-css-pure-367i | codepen, icons, css, webdev | Check out this Pen I made!
{% codepen https://codepen.io/TidyCoder/pen/VwOXQgR %} | tidycoder |
1,897,041 | Setting Up Listmonk: An Open-Source Newsletter Mailing System | If you're looking for a robust, open-source newsletter and mailing list manager, Listmonk is an... | 0 | 2024-06-22T13:12:01 | https://dev.to/aixart/setting-up-listmonk-an-open-source-newsletter-mailing-system-50ga | newsletter, opensource, go, mailing | If you're looking for a robust, open-source newsletter and mailing list manager, Listmonk is an excellent choice. This guide will walk you through the process of setting up Listmonk on your server. The steps below will help you configure your domain, secure it with Let's Encrypt SSL certificates, and customize Listmonk for your needs.
## Prerequisites
Before diving into the setup, ensure you have the following:
- A server instance with Nginx installed.
- Docker and Docker Compose installed on your server.
- A custom domain that you want to use for Listmonk.
- Basic knowledge of shell commands and editing configuration files.
## Step-by-Step Guide
### 1. Clone the Listmonk Repository
Start by cloning the Listmonk repository to your server:
```bash
https://github.com/yasoob/listmonk-setup
```
### 2. Modify `init-letsencrypt.sh`
This script sets up Let's Encrypt SSL certificates for your domain. You'll need to edit the script to include your custom domain and email address.
Open `init-letsencrypt.sh` in your favorite text editor and make the following changes:
- **Line 8**: Replace `example.com` with your custom domain.
- **Line 11**: Add your email address.
```bash
domains=(yourdomain.com)
email="youremail@example.com"
```
### 3. Edit `config.toml`
Next, configure the administrative credentials for Listmonk. Open `config.toml` and modify the following lines:
- **Line 9**: Set your admin username.
- **Line 10**: Set your admin password.
```toml
admin_user = "your_admin_username"
admin_password = "your_admin_password"
```
### 4. Update Nginx Configuration
Listmonk uses Nginx as a reverse proxy. You'll need to update the Nginx configuration to point to your custom domain. Open `data/nginx/nginx.conf` and replace all instances of `example.com` with your domain.
```nginx
server {
listen 80;
server_name yourdomain.com;
location / {
proxy_pass http://listmonk:9000;
...
}
...
}
```
### 5. Obtain SSL Certificates and Launch Listmonk
Run the `init-letsencrypt.sh` script to obtain SSL certificates and start Listmonk:
```bash
./init-letsencrypt.sh
```
This script will handle the SSL certificate setup and launch Listmonk using Docker. Follow the on-screen prompts to complete the process.
### 6. Verify Installation
Once the script completes, open a web browser and navigate to `https://yourdomain.com`. You should see the Listmonk login page. Log in using the admin credentials you set in `config.toml`.
## Conclusion
Congratulations! You now have Listmonk up and running on your custom domain with SSL protection. Listmonk provides a powerful, self-hosted solution for managing newsletters and mailing lists, and with the steps above, you can ensure it's set up securely and customized to your needs.
For more detailed configuration and usage instructions, refer to the [official Listmonk documentation](https://listmonk.app/docs/). Happy mailing! 🚀 | aixart |
1,897,063 | Subnets, Gateways, Route Tables | 🚀 Exciting News! 🚀 I'm thrilled to announce that I've achieved AWS certification! 🎉 After months of... | 0 | 2024-06-22T14:02:59 | https://dev.to/vidhey071/subnets-gateways-route-tables-12nn | aws | 🚀 Exciting News! 🚀
I'm thrilled to announce that I've achieved AWS certification! 🎉
After months of dedicated learning and hard work, I am now officially certified with this certificate. This journey has been incredibly rewarding, and I'm looking forward to leveraging this knowledge to drive innovation and efficiency in cloud computing.
A huge thank you to everyone who supported me along the way. Your encouragement and guidance meant the world to me.
Let's continue to push boundaries and explore new possibilities with AWS! 💡 | vidhey071 |
1,897,062 | How to Deploy an Application Using Nginx as a Web Server | Deploying an application using Nginx as a web server is a common task for developers and system... | 0 | 2024-06-22T14:02:53 | https://dev.to/iaadidev/how-to-deploy-an-application-using-nginx-as-a-web-server-36a | nginx, webdev, deployment, beginners |
Deploying an application using Nginx as a web server is a common task for developers and system administrators. Nginx is known for its performance, stability, rich feature set, simple configuration, and low resource consumption. This blog post will guide you through the process of deploying an application using Nginx, complete with relevant code snippets to make the process as clear as possible.
## Table of Contents
1. Introduction to Nginx
2. Installing Nginx
3. Setting Up Your Application
4. Configuring Nginx
5. Starting and Enabling Nginx
6. Securing Your Deployment with SSL
7. Monitoring and Troubleshooting
8. Conclusion
## 1. Introduction to Nginx
Nginx is an open-source web server that can also be used as a reverse proxy, load balancer, mail proxy, and HTTP cache. Due to its event-driven architecture, it handles multiple client requests efficiently, making it suitable for high-traffic websites and applications.
### Key Features of Nginx:
- High concurrency
- Load balancing
- Reverse proxy capabilities
- Static file serving
- SSL/TLS support
- HTTP/2 support
## 2. Installing Nginx
To install Nginx, you need to have root or sudo privileges on your server. The following steps demonstrate how to install Nginx on a typical Linux-based system such as Ubuntu.
### Installation on Ubuntu:
First, update your package list:
```sh
sudo apt update
```
Then, install Nginx:
```sh
sudo apt install nginx
```
### Verify Installation:
After installation, you can verify that Nginx is installed correctly by checking its version:
```sh
nginx -v
```
You can also start the Nginx service and check its status:
```sh
sudo systemctl start nginx
sudo systemctl status nginx
```
## 3. Setting Up Your Application
For the purpose of this guide, we will deploy a simple web application. You can replace this with your actual application.
### Example Application:
Let’s assume we have a simple Node.js application. Here’s a basic example:
**app.js:**
```javascript
const express = require('express');
const app = express();
app.get('/', (req, res) => {
res.send('Hello, world!');
});
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
console.log(`Server is running on port ${PORT}`);
});
```
### Running the Application:
Make sure you have Node.js and npm installed. Then, you can run your application with:
```sh
node app.js
```
Your application should now be accessible at `http://localhost:3000`.
## 4. Configuring Nginx
Nginx configuration files are typically located in the `/etc/nginx` directory. The main configuration file is `nginx.conf`, and additional site-specific configurations are often stored in the `/etc/nginx/sites-available` directory with symlinks in the `/etc/nginx/sites-enabled` directory.
### Create a Configuration File:
Create a new configuration file for your application:
```sh
sudo nano /etc/nginx/sites-available/myapp
```
Add the following configuration:
```nginx
server {
listen 80;
server_name your_domain_or_IP;
location / {
proxy_pass http://localhost:3000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}
```
Replace `your_domain_or_IP` with your actual domain name or IP address.
### Enable the Configuration:
Create a symlink in the `sites-enabled` directory:
```sh
sudo ln -s /etc/nginx/sites-available/myapp /etc/nginx/sites-enabled/
```
### Test Nginx Configuration:
Before restarting Nginx, test the configuration for syntax errors:
```sh
sudo nginx -t
```
### Restart Nginx:
If the configuration test is successful, restart Nginx to apply the changes:
```sh
sudo systemctl restart nginx
```
Your application should now be accessible through Nginx at `http://your_domain_or_IP`.
## 5. Starting and Enabling Nginx
To ensure Nginx starts on boot, enable the service:
```sh
sudo systemctl enable nginx
```
You can start, stop, and restart Nginx using the following commands:
```sh
sudo systemctl start nginx
sudo systemctl stop nginx
sudo systemctl restart nginx
```
## 6. Securing Your Deployment with SSL
For production applications, securing your site with SSL is crucial. We will use Let’s Encrypt to obtain a free SSL certificate.
### Install Certbot:
Certbot is a client for Let’s Encrypt that automates the process of obtaining and renewing SSL certificates.
On Ubuntu, you can install Certbot and the Nginx plugin with:
```sh
sudo apt install certbot python3-certbot-nginx
```
### Obtain an SSL Certificate:
Run Certbot to obtain a certificate and configure Nginx:
```sh
sudo certbot --nginx -d your_domain
```
Follow the prompts to complete the setup. Certbot will automatically edit your Nginx configuration to use the obtained SSL certificate.
### Automatic Renewal:
Let’s Encrypt certificates are valid for 90 days, but Certbot can handle renewals automatically. To set up automatic renewal, add a cron job:
```sh
sudo crontab -e
```
Add the following line to run the renewal twice daily:
```sh
0 0,12 * * * /usr/bin/certbot renew --quiet
```
## 7. Monitoring and Troubleshooting
### Checking Nginx Logs:
Nginx logs are helpful for troubleshooting issues. By default, they are located in `/var/log/nginx`.
- Access logs: `/var/log/nginx/access.log`
- Error logs: `/var/log/nginx/error.log`
### Common Commands:
- Reload Nginx after changes: `sudo systemctl reload nginx`
- Check Nginx status: `sudo systemctl status nginx`
- View Nginx logs: `sudo tail -f /var/log/nginx/error.log`
### Troubleshooting Tips:
1. **502 Bad Gateway**: This usually indicates that Nginx cannot connect to your application. Ensure your application is running and check the port configuration.
2. **403 Forbidden**: This error occurs due to permission issues. Check the permissions of your web root and the Nginx configuration.
3. **404 Not Found**: Ensure your application routes are correctly defined and the server block in the Nginx configuration points to the correct location.
## 8. Conclusion
Deploying an application using Nginx as a web server involves several steps, from installing Nginx and setting up your application to configuring Nginx and securing your deployment with SSL. With the above guide and relevant code snippets, you should be able to deploy your application efficiently and securely.
Nginx is a powerful tool that, when used correctly, can greatly enhance the performance and security of your web application. Whether you are deploying a simple static site or a complex web application, Nginx provides the flexibility and scalability needed to handle your web traffic effectively.
Feel free to explore more advanced configurations and features of Nginx, such as load balancing, caching, and more, to fully leverage its capabilities for your specific use case. Happy deploying! | iaadidev |
1,897,061 | Amazon Route 53 | 🚀 Exciting News! 🚀 I am thrilled to announce that I have achieved my AWS certification! 🎉 After... | 0 | 2024-06-22T14:02:16 | https://dev.to/vidhey071/amazon-route-53-26ek | aws | 🚀 Exciting News! 🚀
I am thrilled to announce that I have achieved my AWS certification! 🎉 After months of hard work and dedication, I am now certified with this certificate. This accomplishment signifies my commitment to mastering AWS services and best practices, enhancing my skills in cloud computing and infrastructure management.
I am grateful for the support of my colleagues, mentors, and the invaluable resources provided by AWS. This journey has been incredibly rewarding, and I look forward to applying my knowledge to deliver innovative solutions and contribute effectively to our projects.
Thank you all for your encouragement and belief in my abilities. Let's continue to strive for excellence together! | vidhey071 |
1,897,057 | Skill Up Now with Zypher | At Zypher, we believe in the power of education to shape lives and drive positive change. As a... | 0 | 2024-06-22T13:46:43 | https://dev.to/sebastian_kanto_24ab4f24/skill-up-now-with-zypher-6fc | digitalworkplace | At Zypher, we believe in the power of education to shape lives and drive positive change. As a Fastest growing vernacular upskilling platform, we are committed to providing accessible, high-quality learning experiences that empower individuals to reach their full potentia
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](https://zypherlearning.com/) | sebastian_kanto_24ab4f24 |
1,885,475 | United Kingdom study visa | Studying in the UK is a thrilling opportunity for global students, offering a mix of academic... | 0 | 2024-06-12T09:16:04 | https://dev.to/saibhavani_yaxis_346af9ea/united-kingdom-study-visa-f1p | Studying in the UK is a thrilling opportunity for global students, offering a mix of academic excellence, cultural diversity, and career prospects. Here’s a brief guide to acquiring a [United Kingdom study visa](https://shorturl.at/4c9Wk) and maximizing your educational adventure.
Why Study in the UK?
Academic Excellence: The UK is home to some of the world’s top universities known for their quality education and research.
Cultural Experience: Immerse yourself in the rich history and diverse culture of the UK.
Career Opportunities: Gain access to a wide range of internships and job opportunities.
Eligibility for a Study Visa
Acceptance Letter: Obtain an unconditional offer from a recognized UK institution.
Financial Proof: Demonstrate sufficient funds to cover tuition fees and living expenses.
English Language Proficiency: Provide evidence of English language proficiency.
Application Process for a United Kingdom Study Visa
Document Preparation: Gather required documents, including passport, acceptance letter, and financial documents.
Online Application: Complete the online application form and pay the visa fee.
Biometrics Appointment: Schedule and attend a biometrics appointment at a visa application center.
Visa Approval: Once your application is processed, you will receive a decision on your visa application.
Benefits of Studying in the UK
Quality Education: Access world-class education and cutting-edge research facilities.
Cultural Exposure: Experience a vibrant and diverse culture that will broaden your horizons.
Career Development: Benefit from the UK’s strong links with industry and gain valuable work experience.
Conclusion
Studying in the UK offers a unique opportunity to enhance your academic and personal development. By obtaining a United Kingdom study visa, you can embark on a life-changing educational journey. https://shorturl.at/4c9Wk | saibhavani_yaxis_346af9ea | |
1,897,055 | AWS Database Offerings | 🚀 Exciting News! 🚀 I'm thrilled to announce that I've achieved AWS certification! 🎉 After months of... | 0 | 2024-06-22T13:33:57 | https://dev.to/vidhey071/aws-database-offerings-5f25 | aws | 🚀 Exciting News! 🚀
I'm thrilled to announce that I've achieved AWS certification! 🎉
After months of dedicated learning and hard work, I am now officially certified with this certificate. This journey has been incredibly rewarding, and I'm looking forward to leveraging this knowledge to drive innovation and efficiency in cloud computing.
A huge thank you to everyone who supported me along the way. Your encouragement and guidance meant the world to me.
Let's continue to push boundaries and explore new possibilities with AWS! 💡 | vidhey071 |
1,897,054 | AWS Certified Solutions Architect - Professional | 🚀 Exciting News! 🚀 I am thrilled to announce that I have achieved my AWS certification! 🎉 After... | 0 | 2024-06-22T13:33:23 | https://dev.to/vidhey071/aws-certified-solutions-architect-professional-2p27 | aws | 🚀 Exciting News! 🚀
I am thrilled to announce that I have achieved my AWS certification! 🎉 After months of hard work and dedication, I am now certified with this certificate. This accomplishment signifies my commitment to mastering AWS services and best practices, enhancing my skills in cloud computing and infrastructure management.
I am grateful for the support of my colleagues, mentors, and the invaluable resources provided by AWS. This journey has been incredibly rewarding, and I look forward to applying my knowledge to deliver innovative solutions and contribute effectively to our projects.
Thank you all for your encouragement and belief in my abilities. Let's continue to strive for excellence together! | vidhey071 |
1,897,053 | Install react js 18 | what is the step to install react js 18? | 0 | 2024-06-22T13:32:32 | https://dev.to/neshat_imam_f569fa017e4c3/install-react-js-18-89p | what is the step to install react js 18?
| neshat_imam_f569fa017e4c3 | |
1,897,049 | Adapting to Online Exams and Assessments | Adapting to Online Exams and Assessments As education increasingly moves online, students must adapt... | 0 | 2024-06-22T13:27:01 | https://dev.to/gracelee04/adapting-to-online-exams-and-assessments-2d73 | marketing, education, writing, articles | Adapting to Online Exams and Assessments
As education increasingly moves online, students must adapt to new methods [Take My Class Online](https://takemyclassonline.net/) of exams and assessments. This transition from traditional classroom settings to virtual environments requires a different approach to studying, test-taking, and overall academic strategies. Here, we explore the key aspects of adapting to online exams and assessments, providing practical tips and insights to help students succeed in this evolving landscape.
Understanding Online Exams and Assessments
Online exams and assessments come in various formats, including multiple-choice questions, short answers, essays, open-book tests, and even practical tasks. The primary difference between traditional and online exams is the mode of delivery. While the core principles of test-taking remain the same, the online format introduces unique challenges and opportunities.
Types of Online Assessments
Timed Exams: These are similar to in-person exams but conducted online within a specified time frame.
Open-Book Tests: These allow students to refer to their notes, textbooks, and other resources during the exam.
Take-Home Exams: These exams are given with a longer completion window, often ranging from a few hours to several days.
Proctored Exams: These require students to be monitored via webcam and screen-sharing software to ensure academic integrity.
Quizzes and Continuous Assessments: These are shorter, frequent assessments used to gauge ongoing learning progress.
Preparing for Online Exams
Preparation for online exams involves more than just studying the material. It also includes familiarizing oneself with the technical requirements and the online exam platform.
Technical Preparation:
Check Equipment: Ensure your computer, internet connection, webcam, and microphone are working properly.
Know the Platform: Familiarize yourself with the exam software or platform. Practice using any features that will be required during the test, such as uploading files or navigating between questions.
Backup Plan: Have a backup plan in case of technical difficulties, such as an alternate device or internet source.
Study Strategies:
Create a Study Schedule: Plan your study time well in advance, breaking down the material into manageable sections.
Use Online Resources: Utilize online lectures, tutorials, and forums to enhance your understanding of the subject matter.
Practice Tests: Take practice tests under exam conditions to get comfortable with the format and time constraints.
Taking the Exam
When the exam day arrives, being mentally and physically prepared is crucial.
Environment Setup:
Quiet Space: Choose a quiet, distraction-free environment to take the exam.
Organized Workspace: Ensure your workspace is tidy and that you have all necessary materials within reach.
Comfort: Make sure your seating and desk setup are comfortable, as you may be sitting for an extended period.
Time Management:
Pace Yourself: Allocate time to each question based on its marks or complexity. Don’t spend too long on any one question.
Review Time: Leave some time at the end to review your answers and make any necessary corrections.
Exam Strategies:
Read Instructions Carefully: Before starting, read all instructions thoroughly to avoid any misunderstandings.
Answer Easy Questions First: Boost your confidence and secure easy marks by answering simpler questions first.
Stay Calm: If you encounter a difficult question, stay calm and move on to the next one. You can always return to it later.
Post-Exam Review
After the exam, take time to review your performance and understand areas for improvement.
Self-Assessment:
Reflect on Your Performance: Think about what went well and what could have been better.
Analyze Mistakes: Review any mistakes to understand where you went wrong and how to avoid similar errors in the future.
Feedback:
Seek Feedback: If possible, seek feedback from your instructor or peers to gain insights into your performance.
Use Feedback Constructively: Use the feedback to improve your study habits and exam strategies for future assessments.
Overcoming Challenges
Online exams present unique challenges that students must overcome to succeed.
Technical Issues:
Pre-Test Check: Perform a thorough check of your equipment before the exam.
Technical Support: Know how to contact technical support in case of issues during the exam.
Distractions:
Minimize Distractions: Inform family or roommates of your exam schedule and ask for minimal interruptions.
Focus Techniques: Use techniques such as deep breathing or short breaks to maintain focus during the exam.
Academic Integrity:
Understand Policies: Be aware of the academic integrity policies of your institution.
Ethical Behavior: Maintain honesty and integrity in your work, even in an unsupervised environment.
Advantages of Online Exams
Despite the challenges, online exams offer several advantages.
Flexibility: Online exams can often be taken at a time that suits the student, within a given window.
Accessibility: Students from different geographical locations can take exams without the need to travel.
Resource Availability: Open-book and take-home exams allow students to use resources, promoting deeper learning and understanding.
Conclusion
Adapting to online exams and assessments is a vital skill in [Pay someone to Take My Class Online](https://takemyclassonline.net/) today’s digital education landscape. By understanding the different types of online assessments, preparing effectively, managing time and environment during the exam, and reflecting on performance, students can navigate these challenges successfully. Embracing the advantages of online exams while overcoming potential obstacles will not only enhance academic performance but also prepare students for a future where digital proficiency is increasingly essential. With the right strategies and mindset, online exams can be a rewarding and enriching part of the educational journey.
 | gracelee04 |
1,896,668 | Simplifying Persistent Storage in Kubernetes: A Deep Dive into PVs, PVCs, and SCs | In the world of Kubernetes, managing persistent storage efficiently stands as a cornerstone for... | 0 | 2024-06-22T13:19:39 | https://dev.to/piyushbagani15/simplifying-persistent-storage-in-kubernetes-a-deep-dive-into-pvs-pvcs-and-scs-1p3c | kubernetes, storage, persistent, volume | In the world of Kubernetes, managing persistent storage efficiently stands as a cornerstone for deploying resilient and scalable applications. Kubernetes not only orchestrates containers but also offers robust solutions for handling persistent data across these containers.
This blog dives into the critical components of Kubernetes storage management: Persistent Volumes (PV), Persistent Volume Claims (PVC), Storage Classes (SC), and Volume Claim Templates. These elements are pivotal in making Kubernetes a powerhouse for maintaining stateful applications amidst the dynamic nature of containerized environments.
## Persistent Volumes (PV)
Persistent Volumes are one of the building blocks of storage in Kubernetes. A PV is a networked storage unit in the cluster that has been provisioned by an administrator or automatically provisioned via Storage Classes. It represents a piece of storage that is physically backed by some underlying mass storage system, like NFS, iSCSI, or a cloud provider-specific storage system.
### Characteristics of PVs:
- Lifecycle Independence: PVs exist independently of pods' lifecycles. This means that the storage persists even after the pods that use them are deleted.
- Storage Abstraction: PVs abstract the details of how storage is provided from how it is consumed, allowing for a separation of concerns between administrators and users.
- Multiple Access Modes: PVs support different access modes like ReadWriteOnce, ReadOnlyMany, and ReadWriteMany, which dictate how the volume can be mounted on a node.
## Persistent Volume Claims (PVC)
Persistent Volume Claims are essentially requests for storage by a pod. PVCs consume PV resources by specifying size and access modes, like a kind of "storage lease" that a user requests to store their data.
### How PVCs Work:
- Binding: When a PVC is created, Kubernetes looks for a PV that matches the PVC’s requirements and binds them together. If no suitable PV exists, the PVC will remain unbound until a suitable one becomes available or is dynamically provisioned.
- Dynamic Provisioning: If a PVC specifies a Storage Class, and no PV matches its requirements, a new PV is dynamically created according to the specifics of the Storage Class.
## Storage Classes (SC)
Storage Classes define and classify the types of storage available within a Kubernetes cluster. They enable dynamic volume provisioning by describing the "classes" of storage (different levels of performance, backups, and policies).
### Features of SCs:
- Provisioning: Admins can define as many Storage Classes as needed, each specifying a different quality of service or backup policy.
- Automation: Based on the Storage Class specified in a PVC, Kubernetes automates the volume provisioning, without manual PV creation by the administrator.
## Example:
Consider a scenario where a Kubernetes cluster needs to dynamically provide storage for a database application:
```
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: db-storage
spec:
accessModes:
- ReadWriteOnce
storageClassName: fast-disk
resources:
requests:
storage: 100Gi
```
This PVC requests a 100 GiB disk with read-write access on a single node. The fast-disk Storage Class is designed to provision high-performance SSD-based storage, tailored for database applications.
## How It Works:
- PVC Creation: The above PVC is created, requesting specific storage characteristics.
- Dynamic Provisioning: If no existing PV matches the PVC, the Storage Class fast-disk triggers the dynamic creation of a new PV that fits the criteria.
- Binding: The newly created PV is automatically bound to the PVC, ensuring the database application has the necessary storage.
## Conclusion
Understanding PVs, PVCs, and SCs is crucial for effectively managing storage in Kubernetes. These components offer a flexible, powerful way to handle persistent data, ensuring applications can be highly available and resilient. As Kubernetes continues to evolve, the capabilities and complexity of managing storage will likely increase, offering even more robust solutions for cloud-native environments.
## In a nutshell
- PVs act as a bridge between the physical storage and the pods, offering a lifecycle independent of the pods.
- PVCs allow pods to request specific sizes and access modes from the available PVs.
- SCs automate the provisioning of storage based on the desired characteristics, facilitating dynamic storage allocation without manual intervention. | piyushbagani15 |
1,897,045 | AWS Security, Identity and Compliance | 🚀 Exciting News! 🚀 I'm thrilled to announce that I've achieved AWS certification! 🎉 After months of... | 0 | 2024-06-22T13:19:31 | https://dev.to/vidhey071/aws-security-identity-and-compliance-2121 | aws | 🚀 Exciting News! 🚀
I'm thrilled to announce that I've achieved AWS certification! 🎉
After months of dedicated learning and hard work, I am now officially certified with this certificate. This journey has been incredibly rewarding, and I'm looking forward to leveraging this knowledge to drive innovation and efficiency in cloud computing.
A huge thank you to everyone who supported me along the way. Your encouragement and guidance meant the world to me.
Let's continue to push boundaries and explore new possibilities with AWS! 💡 | vidhey071 |
1,897,044 | Database Migration | 🚀 Exciting News! 🚀 I am thrilled to announce that I have achieved my AWS certification! 🎉 After... | 0 | 2024-06-22T13:18:42 | https://dev.to/vidhey071/database-migration-33ej | aws | 🚀 Exciting News! 🚀
I am thrilled to announce that I have achieved my AWS certification! 🎉 After months of hard work and dedication, I am now certified with this certificate. This accomplishment signifies my commitment to mastering AWS services and best practices, enhancing my skills in cloud computing and infrastructure management.
I am grateful for the support of my colleagues, mentors, and the invaluable resources provided by AWS. This journey has been incredibly rewarding, and I look forward to applying my knowledge to deliver innovative solutions and contribute effectively to our projects.
Thank you all for your encouragement and belief in my abilities. Let's continue to strive for excellence together! | vidhey071 |
1,897,043 | NextJS - getServerSideProps | Important Properties in context of getServerSideProps Params -> for dynamic parameters. request... | 0 | 2024-06-22T13:17:59 | https://dev.to/alamfatima1999/nextjs-getserversideprops-981 | Important Properties in context of **getServerSideProps**
**_Params_** -> for dynamic parameters.
**_request_** -> to view the request from the client.
**_response_** -> to set the response for the client.
**_query_** -> to get hold of the query parameter hit in the url.
**What happens at build time?**
1. There is a lambda-symbol against the pages which are server-side-rendered.
2. This symbol states that this page renders at run-time.
3. Also there are no json or html files formed in the app during build.
4. Even after the 1st request the above files are not generated because SSR is basically dependent on run-time requests.
5. Also the problem of stale data is solved as when we refresh the application, the latest data is fetched without the need for a validate key. | alamfatima1999 | |
1,897,042 | In Java what is ConcurrentModificationException? How to avoid it in multi-threading. #InterviewQuestion | Problem Statement: In multi-threaded environments, when multiple threads interact with the... | 0 | 2024-06-22T13:15:48 | https://dev.to/codegreen/in-java-what-is-concurrentmodificationexception-how-to-avoid-it-in-multi-threading-interviewquestion-4p1m | threads, java | ## Problem Statement:
In multi-threaded environments, when multiple threads interact with the same object or collection concurrently, there is a risk of ConcurrentModificationException due to unsynchronized modifications.
## Background
> **ConcurrentModificationException** is thrown by List in Java when the collection is structurally modified (e.g., adding or removing elements) during iteration. This is due to the **modification count** maintained internally by the list, which is checked by iterators to detect **concurrent modifications**. If the modification count changes unexpectedly, it signals that the collection's structure has been altered concurrently, ensuring safe and consistent iteration behavior.
## Solution:
Ensure thread safety by using synchronized blocks or concurrent data structures to manage access and modifications to shared objects or collections.
1. Java ConcurrentModificationException (Without Synchronization)
--------------------------------------------------------------
Example demonstrating ConcurrentModificationException when modifying a collection concurrently without proper synchronization.
```java
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class ConcurrentModificationExample{
public static void main(String[] args) {
List<Integer> numbers = new ArrayList<>();
numbers.add(1);
numbers.add(2);
numbers.add(3);
// Thread 1: Iterating and modifying the list
Thread thread1 = new Thread(() -> {
Iterator<Integer> iterator = numbers.iterator();
while (iterator.hasNext()) {
Integer number = iterator.next();
System.out.println("Thread 1::value=>"+number);
}
});
// Thread 2: Adding an element to the list concurrently
Thread thread2 = new Thread(() -> {
try {
numbers.add(4);
} catch (Exception e) {
e.printStackTrace();
}
});
thread1.start();
thread2.start();
System.out.println("List after modification: " + numbers);
}
}
/*
Output:
Exception in thread "Thread-0" java.util.ConcurrentModificationException
at java.base/java.util.ArrayList$Itr.checkForComodification(ArrayList.java:1043)
at java.base/java.util.ArrayList$Itr.next(ArrayList.java:997)
at ConcurrentModificationExample.lambda$main$0(ConcurrentModificationExample.java:16)
at java.base/java.lang.Thread.run(Thread.java:829)
*/
```
2. Java ConcurrentModificationException Avoided (With Synchronization)
-------------------------------------------------------------------
Example demonstrating how to avoid ConcurrentModificationException by using proper synchronization.
```java
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class ConcurrentModificationExample {
public static void main(String[] args) {
List<Integer> numbers = new ArrayList<>();
numbers.add(1);
numbers.add(2);
numbers.add(3);
// Thread 1: Iterating and removing elements with proper synchronization
Thread thread1 = new Thread(() -> {
synchronized (numbers) {
Iterator<Integer> iterator = numbers.iterator();
while (iterator.hasNext()) {
Integer number = iterator.next();
System.out.println("Thread 1::value=>"+number);
}
}
});
// Thread 2: Adding an element to the list concurrently
Thread thread2 = new Thread(() -> {
synchronized (numbers) {
numbers.add(4);
}
});
thread1.start();
thread2.start();
System.out.println("List after modification: " + numbers);
}
}
/*Output:
Thread 1::value=>1
Thread 1::value=>2
Thread 1::value=>3
List after modification: [1, 2, 3, 4]
*/
```
## Explanation:
- **ConcurrentModificationException Example:** The first example demonstrates a scenario where Thread 1 attempts to iterate over element s from the list while Thread 2 adds an element concurrently, leading to ConcurrentModificationException due to lack of synchronization.
- **ConcurrentModificationException Avoided Example:** The second example shows how to avoid ConcurrentModificationException by using synchronized blocks around critical sections of code where the list is being iterated or modified. This ensures that only one thread accesses the list at a time, preventing concurrent modification issues.
## Conclusion:
Implementing proper synchronization techniques such as using synchronized blocks or concurrent data structures from java.util.concurrent package is essential when working with shared mutable data structures in multi-threaded environments. This ensures thread safety and prevents runtime errors like ConcurrentModificationException in Java programs. | manishthakurani |
1,897,027 | Frontend Interview Preparation Day 2 - Linked List | Hi there 🙏, today is June 22, 2024. So, I woke up at 7 AM ⏰ today, did some morning walk, yoga for 30... | 0 | 2024-06-22T13:13:13 | https://dev.to/nishantsinghchandel/maang-interview-preparation-day-2-linked-list-2kca | webdev, javascript, career, beginners | Hi there :pray:, today is June 22, 2024. So, I woke up at 7 AM :alarm_clock: today, did some morning walk, yoga for 30 mins. Went to temple & then started the routine.
## Today's Plan - :100:
- **June 22 (Sat)**: Study linked lists, practice easy problems. (4 hours)
Watch the videos for linked list from Udemy Course.
[Master the Coding Interview: Data Structures + Algorithms
](https://www.udemy.com/share/1013ja3@8z3jnE8L7842ZCmS_vaEAdTJmJKxuxPyDvHeXHPejNI9tEGIqTlqmNy897xhr198/)
**:white_check_mark: What is linked list?** :chains:
- A linked list is a linear data structure that stores a collection of data elements dynamically.
- Nodes represent those data elements, and links or pointers connect each node.
- Each node consists of two fields, the information stored in a linked list and a pointer that stores the address of its next node.
- The last node contains null in its second field because it will point to no node.
- A linked list can grow and shrink its size, as per the requirement.
- It does not waste memory space.
**:white_check_mark: The linked list mainly has three types, they are:**
1. Singly Linked List
2. Doubly Linked List
3. Circular Linked List
**:white_check_mark: Essential Operation on Linked Lists** :traffic_light:
1. Traversing: To traverse all nodes one by one.
2. Insertion: To insert new nodes at specific positions.
3. Deletion: To delete nodes from specific positions.
4. Searching: To search for an element from the linked list.
**:white_check_mark: Application of a Linked List**
- A linked list is used to implement stacks and queues.
- A linked list also helps to implement an adjacency matrix graph.
- It is used for the dynamic memory location.
- The linked list makes it easy to deal with the addition and multiplication of polynomial operations.
- Implementing a hash table, each bucket of the hash table itself behaves as a linked list.
- It is used in a functionality known as undo in Photoshop and Word.
- With that, you have reached the end of this tutorial on Linked Lists.
**:white_check_mark: Some leet code question which I solved today** :man_technologist:
1. [linked-list-cycle](https://leetcode.com/problems/linked-list-cycle/description/)
2. [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/description/)
3. [Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list/description/)
4. [Intersection of Two Linked Lists](https://leetcode.com/problems/intersection-of-two-linked-lists/description/)
All the above leet code questions are solved from my end, I hope you will also try the same. If you can't solve it no problem. Learn it and try again. Never give up.
> Always remember, your career is a marathon, not a sprint.
**:white_check_mark: Checkout some of my post**
[Frontend Interview Preparation](https://dev.to/nishantsinghchandel/frontend-interview-preparation-cl)
[MAANG Interview Preparation Day 1 - The Plan](https://dev.to/nishantsinghchandel/maang-interview-preparation-day-1-the-plan-3i61)
| nishantsinghchandel |
1,897,040 | The Importance of High-Quality Hotel Slippers for Guest Comfort | The Comfort Advantage of High-Quality Hotel Slippers You expect to be pampered, and one of the perks... | 0 | 2024-06-22T13:10:27 | https://dev.to/molkasn_rooikf_bd180a12bc/the-importance-of-high-quality-hotel-slippers-for-guest-comfort-39mo | The Comfort Advantage of High-Quality Hotel Slippers
You expect to be pampered, and one of the perks of a good hotel stay is the availability of comfortable hotel slippers when you stay in a hotel. High-quality hotel slippers not only provide comfort, but also serve as a amenity valuable guests to enjoy. The slippers that are right make a world of difference in terms of guest satisfaction and experience.
You expect to be spoiled and treated like a king or queen when you stay at a fancy hotel. One of the perks of staying at a hotel good the comfortable slippers they provide for guests. The slippers that are high-quality only feel good, but also make guests happy and satisfied with their stay.
You want to feel happy and cozy when you stay in a great place. Good hotels give their guests slippers that are soft wear inside. These slippers are comfy and make guests feel good.
Innovation in Hotel Slipper Design
The design of hotel slippers has become increasingly innovative in recent years. From eco-friendly materials to features that are high-tech innovation in slipper design has led to even more comfort and convenience for hotel guests.
Recently, designers have been hotel making that are really special. They use new materials that are better for the technology and environment that makes them even more comfortable.
People who make slippers for hotels are coming up with new ideas to better make them. They use things that are good for the Earth and they are made by them extra comfortable.
Safety and Use of Hotel Slippers
Aside from providing comfort, hotel slippers also play a role in keeping guests safe. They can prevent slips and falls on slippery surfaces, offering guests peace of mind as they move around their Hotel Shampoo Set particular hotel room. Hotel slippers are also convenient for use in shared spaces like spas and pools, where guests may not want to go barefoot.
Hotel slippers are not just for Eco Products comfort - they also keep guests safe. They can stop guests from falling and slipping on slippery floors, which is important. Slippers are also helpful in places like pools and spas where you don't around want to walk without shoes.
Hotel slippers are not only nice and soft, they can also keep you from falling. They are good if the floor is wet. You can also use them in a spa or pool so you don't hurt your feet.
Maintaining Quality and Service in Hotel Slipper Provision
To ensure guest satisfaction, hotel staff should strive to maintain always the quality and service of the hotel slipper provision. This means ensuring that slippers are comfortable, clean, and well-stocked. Hotel staff should additionally be attentive to guest feedback, making adjustments as necessary to ensure maximum comfort and convenience for guests.
Hotels need to make sure they always provide high-quality and Hotel Toiletries Set ,service great it comes to their slippers. This means making sure that the slippers are comfy, clean, and that there are always enough for guests. Staff should also listen to feedback from guests and do what they can to make things better.
Hotels have to be sure they give guests nice, clean slippers all the time. They should always have enough slippers for everyone who needs them. If guests tell the people who work in the hotel them better that they don't like the slippers, the hotel should make.
| molkasn_rooikf_bd180a12bc | |
1,897,039 | 토토솔루션은 카지노에 합법인가요? | 카지노 관리 시스템을 선택할 때 카지노는 합법적이고 평판이 좋은 솔루션과 협력하고 있는지 확인하기를 원합니다. 인기를 얻고 있는 시스템 중 하나가 토토솔루션입니다. 이번 글에서는... | 0 | 2024-06-22T13:09:14 | https://dev.to/ayshanoor445/totosolrusyeoneun-kajinoe-habbeobingayo-fc4 | 카지노 관리 시스템을 선택할 때 카지노는 합법적이고 평판이 좋은 솔루션과 협력하고 있는지 확인하기를 원합니다. 인기를 얻고 있는 시스템 중 하나가 토토솔루션입니다. 이번 글에서는 토토솔루션이 카지노에 합법적인 선택인지 판단하기 위해 더 깊이 파고들어 보겠습니다.
먼저, **[토토솔루션](https://9-99ine.com/)**은 카지노 관리에 필요한 모든 것을 원스톱으로 제공할 것을 약속드립니다. 하지만 이 주장이 사실일까요? 이 분석이 끝나면 귀하는 토토솔루션의 기능, 파트너십 및 리뷰를 이해하여 귀하의 카지노에 대한 적법성에 대해 정보에 기초한 결정을 내리게 될 것입니다.
**카지노 토토 솔루션 주요 내용**
토토솔루션은 플레이어 관리, 보안, 마케팅, 운영 등을 포괄하는 완전한 통합형 카지노 관리 플랫폼이 될 것을 약속합니다.
자사의 역량을 검증하는 주요 결제 제공업체, 게임 스튜디오 및 공급업체와 합법적인 파트너십을 맺고 있습니다.
Trustpilot에 대한 고객 리뷰와 사례 연구에 따르면 카지노는 솔루션을 칭찬하는 데 만족했습니다.
토토솔루션은 업계상을 수상하며 기술력과 고객 경험을 더욱 입증했습니다.
플랫폼은 필요와 배포에 따라 소규모 카지노에서 대규모 카지노로 확장될 수 있습니다.
특징에는 직관적인 디자인, 사용자 정의, 강력한 기능 및 연중무휴 다중 채널 지원이 포함됩니다.
구현에는 온보딩 지원이 제공되는 경우 일반적으로 8~12주가 소요됩니다.
가격은 맞춤형이지만 수익과 효율성 증가를 통해 강력한 투자 수익을 목표로 합니다.
결론적으로 토토솔루션은 카지노가 고려해야 할 핵심 약속을 이행하고 합법적인 것으로 보입니다.
**토토솔루션 특징**
토토솔루션은 완벽하게 통합된 카지노 관리 플랫폼임을 자랑스럽게 생각합니다. 핵심 기능 중 일부는 다음과 같습니다.
**플레이어 관리**
토토 솔루션을 사용하면 카지노에서는 지출 습관, 장치 사용, 지리적 위치 및 선호도와 같은 플레이어 데이터를 추적할 수 있습니다. 이 데이터는 타겟 마케팅 캠페인에 사용될 수 있습니다.
**보안 및 규정 준수**
카지노 관리 시스템으로서 [토토솔루션은](https://9-99ine.com/) 엄격한 보안 및 규정 준수 표준을 충족한다고 주장합니다. 민감한 데이터와 정기적인 보안 감사를 위해 은행급 암호화를 사용합니다.
**마케팅 및 충성도**
이 시스템은 로열티 프로그램을 구축하고, 개인화된 커뮤니케이션을 보내고, 캠페인 결과를 분석하는 도구를 제공합니다. 카지노는 최고의 플레이어에게 보상을 제공하고 휴면 플레이어를 다시 참여시킬 수 있습니다.
**운영 및 재무**
기능을 통해 카지노는 재무 보고서를 관리하고, 송장을 생성하고, 직원을 추적하고, 유지 관리 일정을 예약하여 운영을 간소화할 수 있습니다.
**모바일 및 웹 통합**
플랫폼은 완벽하게 반응하며 모든 장치에 최적화되어 있습니다. 운영자와 플레이어 모두 웹이나 토토솔루션 모바일 앱을 통해 기능에 접근할 수 있습니다.
요약하자면, 토토솔루션은 카지노 관리의 모든 측면을 하나의 통합 플랫폼에서 다루는 것을 목표로 합니다.
**하지만 이러한 약속이 현실과 일치합니까?**
**토토솔루션은 합법적인가요? 파트너십 및 통합**
카지노 솔루션의 적법성을 평가할 때 다른 업계 리더의 생각을 조사하는 것이 중요합니다. 평판이 좋은 제3자와의 성공적인 파트너십 및 통합은 토토솔루션의 주장을 입증할 수 있습니다.
**토토솔루션의 주목할만한 제3자 파트너십은 다음과 같습니다:**
입출금 처리를 위해 Visa, Mastercard, PayPal 및 Skrill과 같은 주요 결제 서비스 제공업체와 통합됩니다. 이를 통해 모든 주요 결제 방법을 쉽게 수락할 수 있습니다.
Scientific Games, IGT 및 Novomatic과 같은 주요 게임 및 슬롯 머신 제공업체와 제휴하여 토토 솔루션을 통해 직접 가상 및 라이브 카지노 콘텐츠를 제공합니다.
CRM, 마케팅 자동화, 현금 없는 베팅과 같은 주변 영역의 공급업체와 협력하여 카지노에 추가 기능을 제공할 수 있습니다.
엄격한 규제 및 규정 준수 표준을 충족하기 위한 권장 플랫폼으로 많은 규제 기관에서 선택했습니다.
이러한 파트너십은 토토솔루션이 업계 생태계 내에서 진지하게 받아들여지고 있음을 보여줍니다. 결제, 게임 및 규정 준수 분야의 주요 업체들은 토토 솔루션이 안전하고 합법적인 솔루션임을 검증했습니다.
**토토솔루션에 대한 리뷰는 무엇을 말합니까?**
편견 없는 시각을 얻으려면 온라인 리뷰와 사례 연구를 통해 기존 고객들이 토토솔루션에 대해 어떻게 말하는지 조사하는 것이 중요합니다.
**요약은 다음과 같습니다:**
**신뢰 조종사 리뷰**
신뢰 조종사에서 토토솔루션은 평균 별점 4.6/5개로 5,000개 이상의 리뷰를 보유하고 있습니다. 반복되는 긍정적인 주제는 다음과 같습니다.
운영자와 플레이어 모두를 위한 직관적이고 사용하기 쉬운 플랫폼입니다.
강력한 기능 세트는 하나의 시스템에서 모든 카지노 요구 사항을 처리합니다.
모든 문제에 대한 탁월한 지원과 빠른 해결.
고객 피드백을 기반으로 정기적인 소프트웨어 업데이트와 새로운 기능이 추가됩니다.
**업계 사례 연구**
토토솔루션 웹사이트와 글로벌 게이밍 사업와 같은 디렉토리의 사례 연구는 성공적인 구현을 보여줍니다. 카지노에서는 원활한 마이그레이션, 참여도 증가, 수익 증대를 높이 평가합니다.
**수상 및 표창**
토토솔루션은 기술 혁신, 고객 경험, 가장 빠르게 성장하는 B2B 기업 부문에서 다양한 상을 받았습니다. 이를 통해 해당 기능이 변화를 가져오고 있음을 더욱 입증합니다.
전반적으로 고객 리뷰에 따르면 토토 솔루션은 강력한 지원을 받는 모든 기능을 갖춘 사용자 친화적인 플랫폼입니다. 많은 성공적인 구현과 업계의 인정을 통해 합법성에 대한 신뢰성이 높아졌습니다.
**토토 솔루션이 귀하의 카지노에 적합합니까?**
이 시점에서 토토솔루션은 다음을 통해 카지노 업계에서 신뢰성과 합법성을 구축했음이 분명합니다.
포괄적인 기능 세트
주요 공급업체와의 파트너십
기존 고객의 긍정적인 평가
공간에서의 표창과 수상
하지만 이것이 귀하의 카지노에 특별히 적합한가요? 고려해야 할 몇 가지 요소는 다음과 같습니다.
**규모와 요구사항**
토토솔루션은 소규모 소매 카지노부터 복잡한 요구 사항을 갖춘 대규모 리조트까지 확장이 가능합니다. 기능의 깊이가 귀하의 비즈니스와 일치하는지 평가하십시오.
**비용과 ROI**
가격 모델은 규모, 요구사항, 계약에 따라 달라질 수 있습니다. 운영 및 마케팅 개선을 통해 예상되는 ROI를 고려하세요.
**지원 및 교육**
확장 가능한 옵션을 통해 최고의 지원을 받을 수 있습니다. 온보딩 일정과 제공되는 교육 지원을 이해하세요.
**미래 성장 계획**
지속적인 개선과 새로운 기능을 통해 시간이 지남에 따라 플랫폼이 귀하의 요구에 맞게 어떻게 발전할 수 있는지 논의하십시오.
**자주 묻는 질문**
**토토솔루션은 사용하기 쉽나요?**
네, 토토솔루션은 빠른 채택을 위해 설계된 직관적인 사용자 인터페이스를 갖추고 있습니다.
**토토솔루션은 다른 시스템과 통합되나요?**
예. 다양한 파트너십과 API를 통해 주요 공급업체와 원활하게 연결됩니다.
**토토솔루션은 다양한 규모의 카지노에 맞게 확장할 수 있나요?**
예, 플랫폼은 유연한 배포 옵션을 통해 소규모 소매점이나 대규모 리조트 자산을 수용할 수 있습니다.
**토토솔루션은 고객지원이 잘 되나요?**
예, 여러 채널을 통해 연중무휴 24시간 지원을 제공하며 문제를 빠르게 해결하는 것으로 유명합니다.
**토토솔루션을 구현하는데 얼마나 걸리나요?**
구현 일정은 다양하지만 온보딩 지원은 일반적으로 8~12주 내에 카지노를 시스템에 활성화하는 데 도움이 됩니다.
**토토솔루션의 가격과 비용은 어떻게 되나요?**
가격은 카지노별로 맞춤화되지만 수익 증가, 참여도 증가 및 운영 최적화를 통해 높은 ROI를 제공하는 것을 목표로 합니다.
**결론**
결론적으로, 조사된 증거에 따르면 토토솔루션은 카지노에 대한 합법적인 플랫폼으로 보입니다. 모든 기능을 갖춘 도구 상자, 검증된 기능 및 강력한 업계 파트너십을 제공합니다. 현재 고객의 리뷰는 토토 솔루션이 효과적이고 안정적인 솔루션임을 더욱 입증합니다.
토토 솔루션이 자신의 요구 사항에 적합한지 평가하는 카지노의 경우, 전 세계적으로 소규모 기업부터 대규모 리조트에 이르기까지 모든 것을 성공적으로 관리했다는 사실을 알 수 있습니다. 포괄적인 온보딩 지원은 운영자가 가치를 신속하게 실현하는 데 도움이 됩니다. 토토솔루션을 제대로 활용한다면 귀하의 카지노를 새로운 차원으로 끌어올릴 수 있는 장기적인 파트너가 될 수 있습니다. 전반적으로 운영을 간소화하고 플레이어 경험을 향상시키려는 모든 자산에 적합한 플랫폼으로 적합해 보이며 토토 솔루션이 카지노에 적합한지 결정할 때 고려해야 할 유효한 옵션입니다.
| ayshanoor445 | |
1,897,038 | A Comprehensive Guide to the Data Science Life Cycle with Python Libraries 🐍🤖 | The data science life cycle is a systematic process for analyzing data and deriving insights to... | 0 | 2024-06-22T13:08:50 | https://dev.to/kammarianand/a-comprehensive-guide-to-the-data-science-life-cycle-with-python-libraries-dgd | datascience, machinelearning, python, datasciencelifecyc | The **data science life cycle** is a systematic process for analyzing data and deriving insights to inform decision-making. It encompasses several stages, each with specific tasks and goals. Here’s an overview of the key stages in the data science life cycle along with the Python libraries used:
### 1. **Problem Definition**
- **Objective**: Understand the problem you are trying to solve and define the objectives.
- **Tasks**:
- Identify the business problem or research question.
- Define the scope and goals.
- Determine the metrics for success.
- **Libraries**: No specific libraries needed; focus on understanding the problem domain and requirements.
### 2. **Data Collection**
- **Objective**: Gather the data required to solve the problem.
- **Tasks**:
- Identify data sources (databases, APIs, surveys, etc.).
- Collect and aggregate the data.
- Ensure data quality and integrity.
- **Libraries**:
- `pandas`: Handling and manipulating data.
- `requests`: Making HTTP requests to APIs.
- `beautifulsoup4` or `scrapy`: Web scraping.
- `sqlalchemy`: Database interactions.
### 3. **Data Cleaning**
- **Objective**: Prepare the data for analysis by cleaning and preprocessing.
- **Tasks**:
- Handle missing values.
- Remove duplicates.
- Correct errors and inconsistencies.
- Transform data types if necessary.
- **Libraries**:
- `pandas`: Data manipulation and cleaning.
- `numpy`: Numerical operations.
- `missingno`: Visualizing missing data.
### 4. **Data Exploration and Analysis**
- **Objective**: Understand the data and uncover patterns and insights.
- **Tasks**:
- Conduct exploratory data analysis (EDA).
- Visualize data using charts and graphs.
- Identify correlations and trends.
- Formulate hypotheses based on initial findings.
- **Libraries**:
- `pandas`: Data exploration.
- `matplotlib`: Data visualization.
- `seaborn`: Statistical data visualization.
- `scipy`: Statistical analysis.
- `plotly`: Interactive visualizations.
### 5. **Data Modeling**
- **Objective**: Build predictive or descriptive models to solve the problem.
- **Tasks**:
- Select appropriate modeling techniques (regression, classification, clustering, etc.).
- Split data into training and test sets.
- Train models on the training data.
- Evaluate model performance using the test data.
- **Libraries**:
- `scikit-learn`: Machine learning models.
- `tensorflow` or `keras`: Deep learning models.
- `statsmodels`: Statistical models.
### 6. **Model Evaluation and Validation**
- **Objective**: Assess the model’s performance and ensure its validity.
- **Tasks**:
- Use performance metrics (accuracy, precision, recall, F1-score, etc.) to evaluate the model.
- Perform cross-validation to ensure the model’s robustness.
- Fine-tune model parameters to improve performance.
- **Libraries**:
- `scikit-learn`: Evaluation metrics and validation techniques.
- `yellowbrick`: Visualizing model performance.
- `mlxtend`: Model validation and evaluation.
### 7. **Model Deployment**
- **Objective**: Implement the model in a production environment.
- **Tasks**:
- Integrate the model into existing systems or workflows.
- Develop APIs or user interfaces for the model.
- Monitor the model’s performance in real-time.
- **Libraries**:
- `flask` or `django`: Creating APIs and web applications.
- `fastapi`: High-performance APIs.
- `docker`: Containerization.
- `aws-sdk` or `google-cloud-sdk`: Cloud deployment.
### 8. **Model Monitoring and Maintenance**
- **Objective**: Ensure the deployed model continues to perform well over time.
- **Tasks**:
- Monitor model performance and accuracy.
- Update the model as new data becomes available.
- Address any issues or biases that arise.
- **Libraries**:
- `prometheus`: Monitoring.
- `grafana`: Visualization of monitoring data.
- `MLflow`: Managing the ML lifecycle, including experimentation, reproducibility, and deployment.
- `airflow`: Workflow automation.
### 9. **Communication and Reporting**
- **Objective**: Communicate findings and insights to stakeholders.
- **Tasks**:
- Create reports and visualizations to present results.
- Explain the model’s predictions and insights.
- Provide actionable recommendations based on the analysis.
- **Libraries**:
- `matplotlib` and `seaborn`: Visualizations.
- `plotly`: Interactive visualizations.
- `pandas`: Summarizing data.
- `jupyter`: Creating and sharing reports.
### 10. **Review and Feedback**
- **Objective**: Reflect on the process and incorporate feedback for improvement.
- **Tasks**:
- Gather feedback from stakeholders.
- Review the overall project for lessons learned.
- Document the process and findings for future reference.
- **Libraries**:
- `jupyter`: Documenting and sharing findings.
- `notion` or `confluence`: Collaborative documentation.
- `slack` or `microsoft teams`: Gathering feedback and communication.
By following this life cycle and utilizing these libraries, data scientists can systematically approach problems, ensure the quality and reliability of their analysis, and provide valuable insights to drive decision-making.
---
About Me:
🖇️<a href="https://www.linkedin.com/in/kammari-anand-504512230/">LinkedIn</a>
🧑💻<a href="https://www.github.com/kammarianand">GitHub</a> | kammarianand |
1,897,037 | ANJI ANSHEN SURGICAL DRESSINGS CO., LTD.: Innovations in Medical Supplies | Discovering the Safe and Innovative Medical Supplies from Anji Anshen Surgical Dressings Co... | 0 | 2024-06-22T13:07:14 | https://dev.to/molkasn_rooikf_bd180a12bc/anji-anshen-surgical-dressings-co-ltd-innovations-in-medical-supplies-21l4 | design | Discovering the Safe and Innovative Medical Supplies from Anji Anshen Surgical Dressings Co Ltd
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Safety is really a priority that is top Anji Anshen Surgical Dressings Co Ltd medical materials. The corporation helps to ensure that all its products are tested and meet the security standards lay out by the systems that are regulatory. Its items are free and eco-friendly from toxic materials that could be harmful to the in-patient's health
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| molkasn_rooikf_bd180a12bc |
1,897,036 | Golang beginners | Hi, I’m looking for guys who has recently started learning golang. It would be great to do it... | 0 | 2024-06-22T13:06:24 | https://dev.to/vlad__siomga11/golang-beginners-hej | beginners, programming, softwaredevelopment, go | Hi,
I’m looking for guys who has recently started learning golang. It would be great to do it together👨💻👩💻
My telegram: @f_higf
| vlad__siomga11 |
1,897,035 | Heat Shrink Tube Applications: Versatile Solutions for Cable Protection | Heat Shrink Tube Applications Heat Shrink Tube Applications: Versatile Solutions for Cable... | 0 | 2024-06-22T13:04:35 | https://dev.to/molkasn_rooikf_bd180a12bc/heat-shrink-tube-applications-versatile-solutions-for-cable-protection-5d2m | Heat Shrink Tube Applications
Heat Shrink Tube Applications: Versatile Solutions for Cable Protection
Are you familiar with heat shrink pipes? These tubes are like magic - they shrink when heated to provide a layer cables that are protective wires, and other components that are electrical. You are introduced by this article to the advantages, innovation, safety, use, how to use, service, quality, and application of heat shrink tubes.
Advantages of Heat Shrink Tube Applications
Heat shrink tubes offer several benefits to users. They provide insulation, strain relief, water resistance, chemical resistance, and 1 inch heat shrink tubing . Furthermore, they can be used for color coding, identification, and branding.
Innovation in Heat Shrink Tube Technology
Heat shrink tube technology has improved dramatically in recent years. The tubes are now available in numerous sizes, colors, and materials, including polyolefin, polyimide.
Safety of Heat Shrink Tube Applications
Safety is a priority top working with electrical components. Heat shrink tubes are safe to use, as they are made of non-toxic and materials that 1 4 shrink tubing are environmentally friendly. They do not emit fumes that are harmful gases when heated, and they reduce the risk of electrical shock and fire hazards. Heat shrink tubes also provide a smooth and prevents that are finish are sleek and interference.
Usage of Heat Shrink Tubes
Heat shrink tubes are used in a variety of industries and applications, including electronics, automotive, aerospace, marine, and military. They can be made use of to protect and organize cables, terminals, splices, connectors, and components. They are suitable for indoor and environments that are outdoor and they can resist temperatures that are extreme humidity, and UV exposure.
How to Make Use Of Heat Shrink Tubes
Using heat shrink tubes is straightforward and simple. First, select the tube material and appropriate for your application. Then, place the tube over the component or cable to be protected. Use a 1 4 heat shrink or oven to evenly apply heat to the tube, until it shrinks and conforms to the design of the cable or component.
Service and Quality of Heat Shrink Tubes
Service and quality are critical factors to think about when heat tubes that are choosing. Look for a supplier who offers a big selection of products, fast delivery, and support technical. Check the producer's certifications, such as ISO, UL, and RoHS, to ensure that the products meet industry standards.
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