Is it possible in SASS to inherit from a class in another file?

Question

The question pretty much says it all.

For instance, if I were using, say, Twitter Bootstrap, could I define classes in my own SASS stylesheet that inherit from Bootstrap's CSS classes? Or does inheritance in SASS only work within the scope of a single file?

Debug

Answer 1

YES! its possible.

If you want all <button> elements to inherit the .btn class from Twitter Bootstrap's Default buttons

In your styles.scss file you would have to first import _bootstrap.scss:

@import "_bootstrap.scss";

Then below the import:

button { @extend .btn; }

Nominee

I feel bad for doing this since the other answers pretty much answered this question (I just neglected to check back for a while and then forgot); but I'm accepting your answer because it is the most complete—i.e., it walks me through the whole process. Thanks! – Debug

Does this only work with other SCSS files? Can you not do this with CSS files? – Infernal

Be careful when you use @extend together with bootstrap/any framework, as it may not work as you expect. There are some things to be aware of as outlined in this post: #30745125 – Tillery

But doesn't this duplicate the CSS from bootstrap.scss, if you do that in multiple files in your project? – Ed

Does this import the entire bootstrap.css into styles.css or just .btn? I mean in the output bundle? If it imports entire bootstrap.css, it will increase the size of styles.css unnecessarily. – Womanlike

The @import is not recommended anymore. From the project's page: "The Sass team discourages the continued use of the @import rule. Sass will gradually phase it out over the next few years, and eventually remove it from the language entirely. Prefer the @use rule instead." – Euphemia

extending another @extend .classname is also discouraged. SCSS is getting very confusing. :( – Quarter

Answer 2

**I might be mistaken, but if I get what you're trying to do, can't you just use the @extend .classname; command inside the element that you'd want to extend? Naturally, you should only modify your own code to preserve updatability.

Chace

Answer 3

To my knowledge, you have to use @import of the file containing the classes you want to use into your SASS file in order to utilize them in that file. However, I am not a SASS/SCSS expert, so someone may know of another way to remotely use them that I am not aware of.

Cask

Answer 4

Just as the accepted answer has shown this is possible with @import, however @import has been deprecated by sass

The Sass team discourages the continued use of the @import rule. Sass will gradually phase it out over the next few years, and eventually remove it from the language entirely. Prefer the @use rule instead.

The @use rule is better suited for use now, since it does not pollute the scope of the importing (user) module. unfortunately at the time of writing the use rule is only implemented in Dart sass.

Jailer

theres a dart sass compiler that compiles sass using @use just fine. But you have to target which file you want to compile in the settings or else all files will be compiled, even if you want to combine them in one file and only compile that one. – Mosera