PostCSS Custom Media With spaces

PostCSS Custom Media lets you use Custom Media Queries in CSS, following the CSS Media Queries specification.

@custom-media --small-viewport (max-width: 30em);

@media (--small-viewport) {
  /* styles for small viewport */
}

/* becomes */

@media (max-width: 30em) {
  /* styles for small viewport */
}

IMPORTANT

This project is a fork for https://github.com/postcss/postcss-custom-media to support custom media using with spaces aftel left and before tight brackets:

In original lib you can use only media without brackets:

@media (--my-custom-media) {

    #myBlock {
        ...
    }
}

Here you can also use it with brackets:

@media ( --my-custom-media ) {

    #myBlock {
      ...
    }
}

It is useful when we have deal with stylelint media-feature-parentheses-space-inside rule.

PR is created to ad this to base lib: https://github.com/postcss/postcss-custom-media/pull/59

New tests are created and passed to check that added functionality is worked.

Usage

Add PostCSS Custom Media to your project:

npm install postcss-custom-media --save-dev

Use PostCSS Custom Media to process your CSS:

const postcssCustomMedia = require('postcss-custom-media');

postcssCustomMedia.process(YOUR_CSS /*, processOptions, pluginOptions */);

Or use it as a PostCSS plugin:

const postcss = require('postcss');
const postcssCustomMedia = require('postcss-custom-media');

postcss([
  postcssCustomMedia(/* pluginOptions */)
]).process(YOUR_CSS /*, processOptions */);

PostCSS Custom Media runs in all Node environments, with special instructions for:

| Node | PostCSS CLI | Webpack | Create React App | Gulp | Grunt | | --- | --- | --- | --- | --- | --- |

Options

preserve

The preserve option determines whether custom media and atrules using custom media should be preserved in their original form.

@custom-media --small-viewport (max-width: 30em);

@media (--small-viewport) {
  /* styles for small viewport */
}

/* becomes */

@custom-media --small-viewport (max-width: 30em);

@media (max-width: 30em) {
  /* styles for small viewport */
}

@media (--small-viewport) {
  /* styles for small viewport */
}

importFrom

The importFrom option specifies sources where custom media can be imported from, which might be CSS, JS, and JSON files, functions, and directly passed objects.

postcssCustomMedia({
  importFrom: 'path/to/file.css' // => @custom-selector --small-viewport (max-width: 30em);
});

@media (max-width: 30em) {
  /* styles for small viewport */
}

@media (--small-viewport) {
  /* styles for small viewport */
}

Multiple sources can be passed into this option, and they will be parsed in the order they are received. JavaScript files, JSON files, functions, and objects will need to namespace custom media using the customMedia or custom-media key.

postcssCustomMedia({
  importFrom: [
    'path/to/file.css',
    'and/then/this.js',
    'and/then/that.json',
    {
      customMedia: { '--small-viewport': '(max-width: 30em)' }
    },
    () => {
      const customMedia = { '--small-viewport': '(max-width: 30em)' };

      return { customMedia };
    }
  ]
});

exportTo

The exportTo option specifies destinations where custom media can be exported to, which might be CSS, JS, and JSON files, functions, and directly passed objects.

postcssCustomMedia({
  exportTo: 'path/to/file.css' // @custom-media --small-viewport (max-width: 30em);
});

Multiple destinations can be passed into this option, and they will be parsed in the order they are received. JavaScript files, JSON files, and objects will need to namespace custom media using the customMedia or custom-media key.

const cachedObject = { customMedia: {} };

postcssCustomMedia({
  exportTo: [
    'path/to/file.css',   // @custom-media --small-viewport (max-width: 30em);
    'and/then/this.js',   // module.exports = { customMedia: { '--small-viewport': '(max-width: 30em)' } }
    'and/then/this.mjs',  // export const customMedia = { '--small-viewport': '(max-width: 30em)' } }
    'and/then/that.json', // { "custom-media": { "--small-viewport": "(max-width: 30em)" } }
    cachedObject,
    customMedia => {
      customMedia    // { '--small-viewport': '(max-width: 30em)' }
    }
  ]
});

See example exports written to CSS, JS, MJS, and JSON.