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As we saw previously when we rendered the HTML page of our CV,

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one of the components is an image tag and it has a image file that it needs to

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render. But it looks pretty broken when we rendered HTML.

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So if we go ahead and open up the Chrome developer tool

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which is under view, developer, and developer tools,

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then if we go to console

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you'll see that we actually get a bunch of 404 errors and they relate

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to the styles.css file as well as the angela.png file.

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That is what this is referring to.

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And you can actually see

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we get the same 404 errors when we look at the debug log in here as

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well. So we're missing some stuff basically. Well, firstly,

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let's see if we can recover it.

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We can go ahead and save this image from the website

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which I'll just call angela.png.

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And then we can drag this image into our personal site.

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And there it is right there. Now, in my case,

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my image actually happens to be a circular one

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which I edited in Photoshop,

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but you might just have a square one and it doesn't matter at all.

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Now that we've got our image inside our project,

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how do we make sure that that image actually gets rendered in our HTML site?

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Because here is the image tag and it's looking inside Angela's personal site

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files for angela.png, which is not what we have here.

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In fact, if we had moved this PNG file to the same

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folder so they're on the same hierarchy, basically inside the same folder,

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well then we could probably just change this to angela.png.

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If I go ahead and restart and rerun my server after I've added in all these

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files and I go to my personal site and I hit reload,

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you'll see that there's still no photo. So why is that? Well,

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back to the Flask documentation we go.

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The reason is because, just like our templates have to be inside a folder called

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templates, Flask will look for all your static files

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like your images or your CSS files inside a folder called static.

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So you have to put it inside a folder called static.

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They made the framework, they make the rules. So inside our project

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my-personal-site, let's create a new directory called static and let's move our

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image into that static folder.

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Now inside our angela.html, when we want to point to that image,

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then the path is going to be static/ the name of the file inside

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that folder, which in my case is angela.png. Now,

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if I go ahead and rerun my application,

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then go back to my homepage and refresh,

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you should see that image being rendered.

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It was able to look inside the static folder and find that image.

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Whenever you create a Flask application, 9 out of 10 times

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you'll need to create it with the templates folder and the static folder.

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And you put all your static files like your CSS files or your images or your

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videos inside that folder

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and your file path is relative to that folder.

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And then when you create your HTML templates,

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you're going to put it inside the templates folder.

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Now going back to my project,

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I'm going to delete all the extra files that we created just now in the demo.

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Right.

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And I should now only end up with my index.html

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which is our simple website. Now,

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the reason why I wanna keep it simple is just so that you really understand

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everything from the ground up.

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And the challenge I've got for you is to go ahead and create a CSS style sheet,

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and then using the style sheet

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change the background of the body of this index.html website to purple.

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That's the goal. You are going to have to change the server.py,

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you're going to have to change the index.html,

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and you're going to have to create a CSS file.

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Pause the video and see if you can complete this challenge.

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Right.

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All right. The first thing we're going to do is create a CSS file.

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That is going to be a static file.

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We're going to create it inside the static folder.

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So I'm going to call it styles.css

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and now I'm going to go ahead and target the body of my website to the body tag,

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and then I'm going to change the background color to purple

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like this.

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So very simple CSS code here. Now that when it's run is going to target this body

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tag which is basically the body of our website

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and hopefully it's going to turn the background purple. Now,

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in order for that CSS to work though,

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we're going to have to add it into the head of our HTML file just as we've done

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it thousands of times before when we did the lessons on CSS and HTML.

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In order to add that in, we're going to create a link element

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which is going to have a relationship. Now,

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the relationship is going to be a style sheet.

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So it's basically telling the HTML file that this link points to a style sheet.

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And then the href of the style sheet is going to be inside static/

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styles.css.

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Now let's go ahead and save both of these files and go back to our server and

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make sure that we're rendering that HTML template which is index.html.

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And now if we go ahead and stop and restart this project so that it takes into

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account all the new files, and then we go to our homepage,

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hopefully it should show you a page that has a purple background

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like you see here. Now,

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one of the things you have to be careful about Chrome is that it likes to cache

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your static files. So what does this mean? Well,

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let's go back to the styles.css and I'm going to change that background-color

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to red. Now I'm going to hit save on this file.

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I'm even going to stop and rerun my file,

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but you can see if I refresh this page, it's still purple.

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And if I go into the Chrome developer tools and we take a look at our elements,

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you can see that the body still has CSS saying that the background color should

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be purple. If we go to the sources inside the static folder,

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there's our styles.css. And you can see

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this is an older version of our style sheet. So what's going on?

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Is it because we didn't save this change? No, we definitely saved it.

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What's actually happening is that to save your internet usage,

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Chrome likes to cache the style sheets and other static files,

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so images or JavaScript.

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and the reason why it does that is because when you visit a website,

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if you're visiting it on the same day,

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these static files are unlikely to change.

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A website is unlikely to update their CSS or their images over one day.

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So once the browser downloads it,

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it keeps hold of those static files.

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This just means that you don't have to keep downloading these large files every

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single time you hit up the same website.

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That's kind of good if we are in fact visiting a real live website.

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But when we're testing, it's a little bit confusing.

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So one of the things you have to do is you have to get Chrome to hard reload.

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And you can do that by holding down the shift key and clicking on this refresh

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button, which is going to do a hard reload.

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And it's going to get rid of all the cached files and pull in any new files.

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So now the background changes to red. And we can confirm that by... let's change

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this to blue hit save on that file, holding down shift, reload,

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and we get the blue background updating.

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So that's just something to be careful about when you find that your CSS files

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or your other static files are not being changed or not being rendered.