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The Sass preprocessor takes a Sass file and translates it into plain CSS the browser can read. In this video, you'll learn the commands to compile Sass to CSS.
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Earlier, you learned that the Sass
preprocessor takes a Sass file and
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translates it into plain
CSS the browser can read.
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One of the quickest and most direct ways
to make this happen is in the terminal or
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console, using the command line.
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Now, if you've never
used the command line,
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don't worry, you don't need to be an
expert with the command line to use sass.
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In this video I'll teach you
a couple of friendly commands to get
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sass running quickly.
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Sass works like this.
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You put sass input into the compiler and
get CSS output on the other side.
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The sass command tells the compiler
which files to process.
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While the sass command accepts many
different bits of information,
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at the very least, you need to provide
it the path to the input file, and
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the path to the output file.
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To get started, we need a sass file.
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We'll use the file input.scss since
we're going to be writing SCSS syntax in
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this course.
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You can delete input.sass from your files.
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Now over in the console, type the command
sass, followed by a space, and
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the name of your sass file.
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In our case, it's input.scss.
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Then we'll need to specify
the output CSS file.
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If you haven't created a CSS
file at this point that's okay.
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The sass command will generate one for
you.
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Let's name the output file, output.css.
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Run the command by pressing Enter.
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And once you refresh the side bar and
workspaces by Ctrl or
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right-clicking the side bar and
clicking Refresh,
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you'll see that sass created a new
folder and a couple of new files.
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The only file we're concerned
with right now is output.css.
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Open up the file, and
you'll see that it contains plain CSS.
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This is a file you link to your HTML.
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You should never edit the output.css file.
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This file is created by sass, and
you shouldn't work directly in the file.
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You should only edit the .scss files.
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Right now the output.css doesn't look
much different than input.scss, because
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as I mentioned in the previous video,
you can add plain CSS to any SCSS file.
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However, we'll soon be using sass specific
features like variables, mixins and
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nesting, using sass syntax
that isn't valid CSS.
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At that point you'll see how sass
is translated into plain CSS.
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Sass also generated a new
file named output.css.map.
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You won't need to write too
much about this file right now.
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Sass created this file to make
our lives a little easier, if and
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when we have to debug styles in the
browser using a tool like Chrome DevTools.
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You'll learn more about
that in a later video.
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Also, sass creates these sass-cache holder
to speed up the compiling of sass to CSS,
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by caching parts of our sass code.
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You'll usually leave this folder alone,
and you won't need it for
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this course since our
sass files will be small.
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In fact, you can delete the folder
from your project without a problem.
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Running the command sass
input.scss output.css
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every time you make a change to the input
file is extremely tedious, right?
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Fortunately, sass comes with a built
in feature called a watcher,
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that constantly detects changes
made to your input file.
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So anytime you save a change in your
sass files, the watcher automatically
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recompiles it, and overwrites
the output.css with the latest changes.
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To enable the watcher, you pass the watch
option to the sass command, like so.
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Sass --watch followed
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input.scss:output.css.
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After running the command, you should see
the message, Sass is watching for changes.
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Press Ctrl-C to stop in
your console output.
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Great, now any time you add a new code or
make a change to your sass file,
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simply save the changes and
you should see the console output,
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Change detected to
input.scss write output.css.
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This means that your changes were
successfully written to output.css.
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Now when you need to stop running
the watcher press Ctrl+C.
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When you preview
the workspace in the browser,
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you'll see the beginnings of the virtual
reality blog we're going to be building
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this course using the awesome
features of sass.
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And when you're all finished,
it's going to look like this.
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See you in the next video.
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