SASS - use variables across multiple files

Question

I would like to keep one central .scss file that stores all SASS variable definitions for a project.

// _master.scss 

$accent: #6D87A7;           
$error: #811702;
$warning: #F9E055;
$valid: #038144;
// etc... 

The project will have a large number of CSS files, due to its nature. It is important that I declare all project-wide style variables in one location.

Is there a way to do this in SCSS?

Answer 1

You can do it like this:

I have a folder named utilities and inside that I have a file named _variables.scss

in that file i declare variables like so:

$black: #000;
$white: #fff;

then I have the style.scss file in which i import all of my other scss files like this:

// Utilities
@import "utilities/variables";

// Base Rules
@import "base/normalize";
@import "base/global";

then, within any of the files I have imported, I should be able to access the variables I have declared.

Just make sure you import the variable file before any of the others you would like to use it in.

Answer 2

This question was asked a long time ago so I thought I'd post an updated answer.

You should now avoid using @import. Taken from the docs:

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

A full list of reasons can be found here

You should now use @use as shown below:

_variables.scss

$text-colour: #262626;

_otherFile.scss

@use 'variables'; // Path to _variables.scss Notice how we don't include the underscore or file extension

body {
  // namespace.$variable-name
  // namespace is just the last component of its URL without a file extension
  color: variables.$text-colour;
}

You can also create an alias for the namespace:

_otherFile.scss

@use 'variables' as v;

body {
  // alias.$variable-name
  color: v.$text-colour;
}

EDIT As pointed out by @und3rdg at the time of writing (November 2020) @use is currently only available for Dart Sass and not LibSass (now deprecated) or Ruby Sass. See https://sass-lang.com/documentation/at-rules/use for the latest compatibility

Answer 3

This answer shows how I ended up using this and the additional pitfalls I hit.

I made a master SCSS file. This file must have an underscore at the beginning for it to be imported:

// assets/_master.scss 
$accent: #6D87A7;           
$error: #811702;

Then, in the header of all of my other .SCSS files, I import the master:

// When importing the master, you leave out the underscore, and it
// will look for a file with the underscore. This prevents the SCSS
// compiler from generating a CSS file from it.
@import "assets/master";

// Then do the rest of my CSS afterwards:
.text { color: $accent; }

IMPORTANT

Do not include anything but variables, function declarations and other SASS features in your _master.scss file. If you include actual CSS, it will duplicate this CSS across every file you import the master into.

Answer 4

In angular v10 I did something like this, first created a master.scss file and included the following variables:

master.scss file:

$theme: blue;

$button_color: red;

$label_color: gray;

Then I imported the master.scss file in my style.scss at the top:

style.scss file:

@use './master' as m;

Make sure you import the master.scss at the top.

m is an alias for the namespace;

Use @use instead of @import according to the official docs below:

https://sass-lang.com/documentation/at-rules/import

Then in your styles.scss file you can use any variable which is defined in master.scss like below:

someClass {

   backgroud-color: m.$theme;

   color: m.$button_color;

}

Hope it 'll help...

Happy Coding :)

Answer 5

Create an index.scss and there you can import all file structure you have. I will paste you my index from an enterprise project, maybe it will help other how to structure files in css:

@import 'base/_reset';

@import 'helpers/_variables';
@import 'helpers/_mixins';
@import 'helpers/_functions';
@import 'helpers/_helpers';
@import 'helpers/_placeholders';

@import 'base/_typography';

@import 'pages/_versions';
@import 'pages/_recording';
@import 'pages/_lists';
@import 'pages/_global';

@import 'forms/_buttons';
@import 'forms/_inputs';
@import 'forms/_validators';
@import 'forms/_fieldsets';

@import 'sections/_header';
@import 'sections/_navigation';
@import 'sections/_sidebar-a';
@import 'sections/_sidebar-b';
@import 'sections/_footer';

@import 'vendors/_ui-grid';

@import 'components/_modals';
@import 'components/_tooltip';
@import 'components/_tables';
@import 'components/_datepickers';

And you can watch them with gulp/grunt/webpack etc, like:

gulpfile.js

// SASS Task

var gulp = require('gulp');
var sass = require('gulp-sass');
//var concat = require('gulp-concat');
var uglifycss = require('gulp-uglifycss');
var sourcemaps = require('gulp-sourcemaps');

gulp.task('styles', function(){
    return gulp
            .src('sass/**/*.scss')
            .pipe(sourcemaps.init())
            .pipe(sass().on('error', sass.logError))
            .pipe(concat('styles.css'))
            .pipe(uglifycss({
                "maxLineLen": 80,
                "uglyComments": true
            }))
            .pipe(sourcemaps.write('.'))
            .pipe(gulp.dest('./build/css/'));
});

gulp.task('watch', function () {
    gulp.watch('sass/**/*.scss', ['styles']);
});

gulp.task('default', ['watch']);

Answer 6

As previously mentioned, the use of @import is discouraged in newer versions of SASS. Use @use "path to SASS partial file" at the top of your file instead.*

You need to import (using @use) the partial SASS file into each SASS file that uses it - not just your main one.

Let's say we have a SASS file called _variables.scss* in a folder called partials that we want to use in header.scss. So in header.scss you write:

@use "partials/variables" as *

Now you can use all the variables defined in _variables.scss* with $variable (no prefix). Alternatively, you can use a namespace (like Christian already mentioned)

@use "partials/variables" as v

to refer to the variables inside _variables.scss* with v.$variable.

* Note that the SASS compiler ignores underscores so that there isn't a separate CSS file generated for each partial SASS file. Instead you can just import them all into your main SASS file with @use.

Answer 7

How about writing some color-based class in a global sass file, thus we don't need to care where variables are. Just like the following:

// base.scss 
@import "./_variables.scss";

.background-color{
    background: $bg-color;
}

and then, we can use the background-color class in any file. My point is that I don't need to import variable.scss in any file, just use it.

Answer 8

I found a solution for vue3 using vite. If you are using dart-sass, you can get around the global limitation of sass modules by using @forward and @use.

_master.scss

$accent: #6D87A7;           
$error: #811702;
$warning: #F9E055;
$valid: #038144;
// etc... 

_global.scss

@forward '_master.scss';
// etc...

Then under the vite.config.js configure your css options as

export default defineConfig({
  css: {
    preprocessorOptions: {
      scss: {
        additionalData: `
          @use "./<path-to-file>/_globals.scss" as *;
        `,
      },
    },
  },
// etc...
});

As mentioned in the sass docs when importing modules without a namespace

We recommend you only do this for stylesheets written by you, though; otherwise, they may introduce new members that cause name conflicts!

You can then use other @use modules in any other stylesheets or components as following

// component file needing a function module

@use 'functions.scss';