Datasets:
pre-view
/
CS50-raw

Dataset card Data Studio Files
xet
 Community
1
text
stringlengths
1
81
start
float64
0
10.1k
duration
float64
0
24.9
it apply to both of these headings.
2,690.63
2.44
And, in fact, there is a way to do that.
2,693.07
1.67
What we can do is instead of doing what we might call inline styling,
2,694.74
4.2
where we take the CSS code and place it directly
2,698.94
3.63
as an attribute of an HTML element, we can move our style code
2,702.57
4.59
to an entirely different part of the web page.
2,707.16
3.56
Recall again that at the top of our HTML page,
2,710.72
2.67
we have this head section that just includes
2,713.39
2.67
information that's useful to know about the web page,
2,716.06
2.82
but isn't actually part of the body of the web page, the content
2,718.88
3.18
that the user sees.
2,722.06
1.11
This head section is a great place where we
2,723.17
1.8
can begin to put some style information, information about how we would
2,724.97
3.96
like for this web page to be styled.
2,728.93
2.97
So what I can do here is instead of putting these style
2,731.9
3.54
attributes inside inline with these HTML elements,
2,735.44
4.71
I can inside of the head section of my web page
2,740.15
3.04
add a style element, where in between the opening style tag and the closing
2,743.19
6.17
style tag, I can add any of the style information that I want.
2,749.36
5.04
And here's the way that syntax is going to look.
2,754.4
2.22
I first need to specify, what types of elements am I going to style?
2,756.62
4.44
And in this case, I want to style all of the h1s.
2,761.06
3.03
So I can just say h1.
2,764.09
3.06
And then all of the style code is going to go inside
2,767.15
3.96
of a pair of curly braces, where I can say I would like the color to be blue
2,771.11
4.56
and I would like the text align property to be centered.
2,775.67
4.37
So now, here's what I've done.
2,780.04
1.86
I've taken the CSS code that used to be down here inside the body of the page
2,781.9
4.7
actually as an attribute of these h1 elements.
2,786.6
2.91
And I've moved the style-related code to a different part of my page altogether.
2,789.51
5.16
Now, the style information is inside the header of my page,
2,794.67
3.06
inside of the style element, where I've said for every h1 element,
2,797.73
4.51
here's how you should style it.
2,802.24
1.4
The styling is in between the opening and curly closing braces here.
2,803.64
3.45
And I've said that every h1 should have a color of blue.
2,807.09
3.74
And every h1 should have a text a line property of center.
2,810.83
4.45
And that is then going to apply to all of the h1 elements
2,815.28
3.33
that my web page happens to find inside the body of my web page.
2,818.61
4.08
So there's a couple of advantages here.
2,822.69
1.63
Advantage number one is what we talked about a moment ago.
2,824.32
2.45
I don't need to duplicate the same code in both of these h1 elements.
2,826.77
4.17
I can write at once and say, apply this styling
2,830.94
2.55
to all of the h1s that show up in the page.
2,833.49
2.81
An advantage number two is we've been able to factor out the style
2,836.3
4
code to somewhere else, just to make it a little bit cleaner.
2,840.3
3.01
So that instead of having a really long line, you might imagine,
2,843.31
2.78
if we had not just two, but maybe five or six or seven different CSS
2,846.09
3.28
properties, that would have taken up a lot of space on one line.
2,849.37
3.45
I can instead in a more readable, more organized way,
2,852.82
3.26
move that style-related code to the style element
2,856.08
2.91
at the beginning of the page just to make it easier to read,
2,858.99
3.1
easier to visually understand, and just to clean up the body of the web page
2,862.09
3.77
as well.
2,865.86
0.9
And that's going to be another of the key themes that's
2,866.76
1.71
going to come up again and again in this class, this idea of separating things
2,868.47
3.3
out so that every piece can sort of be independent of one another.
2,871.77
3.5
Our structure of the web page inside the body is separate from the style.
2,875.27
3.91
And we'll see the same sort of idea appear again and again, as we begin
2,879.18
3.33
to try to design web applications well.
2,882.51
3.78
So now if I take this exact same page and go ahead and refresh style.html,
2,886.29
6.36
we'll see that we see the exact same thing.
2,892.65
3.09
Both of the headings still show up as centered.
2,895.74
2.13
Both of them still show up as blue.
2,897.87
1.95
But now we have the advantage of having only
2,899.82
1.86
written the style code once instead of needing to write the exact same style
2,901.68
4.17
code multiple times in the same way.
2,905.85
3.61
But it turns out that we can even do a little bit better
2,909.46
2.64
than this, because one thing you might imagine
2,912.1
2.7
is that if I have a web application or a website that has multiple different web
2,914.8
3.9
pages, it's probably going to be likely that each of those web pages
2,918.7
4.2
might need to be styled in similar ways.
2,922.9
2.43
If I have a big banner at the top of one web page,
2,925.33
2.55
then in other pages related to that page,
2,927.88
2.52
I might want the same banner, styled in the same way,
2,930.4
2.79
using similar style information.
2,933.19
2.28
And right now, our CSS code is specific to one particular page.
2,935.47
5.43
And it's not going to be easy to then take that same styling
2,940.9
2.94
and apply it to another page.
2,943.84
1.53
If I wanted to, I'd need to copy the exact same CSS code,
2,945.37
3.51
put it inside of another page.
2,948.88
1.54
But then we run into the same problem of duplication,
2,950.42
2.57
where I've now had to repeat myself across multiple different pages,
2,952.99
3
putting the exact same CSS code across all those different pages.
2,955.99
4.15
So there is an improvement we can make.
2,960.14
1.91
And the improvement we can make is to take that CSS code
2,962.05
3.93
and just move it to an entirely different file.
2,965.98
3.25
So instead of putting this style code inside of a style element
2,969.23
3.65
inside of this HTML page, I'll just create a new file
2,972.88
3.87
that I'll call styles.css, inside of which is going to be all of the CSS
2,976.75
5.52
that I care about.
2,982.27
1.08
I want to take every h1, I want to change its color to blue.
2,983.35
3.49
And now, I want to change its text align property to center.
2,986.84
4.51
And now, inside of my HTML page, I no longer need to include any CSS at all.
2,991.35
5.91
Instead of this style element altogether,
2,997.26
2.27
I can just link my CSS code in that CSS file, called styles.css,
2,999.53
5.55
to this particular HTML page.
3,005.08
3.06
And how do I link the styles.css file?
3,008.14
2.37
Well, I can do so again in the head section of my web page
3,010.51
3.18
using a link tag, where I can say I'd like this link
3,013.69
4.2
to be the relationship is it's going to be a style sheet,
3,017.89
3.85