SASS Placeholder for media query? - sass

Question

I found this method to easily add #media block using mixin:
#mixin phone() {
#media only screen and (max-width: 480px) {
#content;
}
}
To use it, just simply type something like this:
p {
#include phone { ... }
span {
#include phone { ... }
}
}
But the problem lies in the real CSS output:
#media only screen and (max-width: 480px) {
p { ... }
}
#media only screen and (max-width: 480px) {
p span { ... }
}
It duplicates the #media ... part which will bloat the CSS.
Is there a way to make the mixin act like placeholder? So it will combine all #content and put it under the same #media ... block.
So the result will be like
#media only screen and (max-width: 480px) {
p { ... }
p span { ... }
}
I know I can just put the #include phone at the end of the file and write all the necessary styles in that block.
But writing the media-query style right besides the original one makes it easier to read and organize.
Thanks

Answer 1

Sass does not have that functionality at this time. Your only option is to manually group your styles within a single media query (or use a 3rd party CSS compressor that has that functionality).
https://github.com/nex3/sass/issues/116

Answer 2

You just have to adjust your nesting. Because the mixin will place all your content within the media-query, you only want to use the mixin once and place all relevant styles within it (to avoid multiple media-queries).
#include phone {
p {
span { ... }
}
}
If you are trying to combine styles for <p> and <span> for various media-queries, you will inevitably end up with some separation of styles, either in your preprocessed or output code.
For example:
p {
...
span { ... }
#include phone {
...
span { ... }
}
}
Hope that helps. Even if you end up with output that feels 'less efficient', it shouldn't actually slow down browser rendering, so I'd say prioritize writing code that feels maintainable to develop.

Answer 3

SASS can not combine extends with media queries**, so duplicate media queries are currently inevitable when you adopt this code style.
You could structure your code with media queries at the top level (i. e. group code by media queries), but this is generally a bad idea. Eric Meyer, one of the CSS gurus here, says (and many other front end enthusiasts would agree) that you should never do that. I have tried this approach myself on one project and i confirm that the larger your project gets, the more painful this code structure appears. SMACSS and other code structure methodologies also advise against it.
Where this code structure is widely used is in CMS base themes (theme templates aka starter kits). But they are aimed to allow users quickly override default styles rather than build from scratch.
The matter is that the duplicate media queries don't really matter. Though #cimmanon might not agree with me, only the readabiliy and maintainability of your source code (SASS) should matter, because every modern web server provides compression (gzip) for CSS code which is read only by machine.
Of course, there are many ways of ruining your CSS by making it unreasanably huge. Using a non-semantic CSS framework is one of them. Wisely applying a lot of local media query blocks is not.