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    postcss-custom-properties
    TypeScript icon, indicating that this package has built-in type declarations

    12.1.9 • Public • Published

    PostCSS Custom Properties PostCSS

    NPM Version CSS Standard Status Build Status Discord

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

    'Can I use' table

    :root {
      --color: red;
    }
    
    h1 {
      color: var(--color);
    }
    
    /* becomes */
    
    :root {
      --color: red;
    }
    
    h1 {
      color: red;
      color: var(--color);
    }

    Note: This plugin only processes variables that are defined in the :root selector.

    Usage

    Add PostCSS Custom Properties to your project:

    npm install postcss-custom-properties --save-dev

    Use PostCSS Custom Properties as a PostCSS plugin:

    const postcss = require('postcss');
    const postcssCustomProperties = require('postcss-custom-properties');
    
    postcss([
      postcssCustomProperties(/* pluginOptions */)
    ]).process(YOUR_CSS /*, processOptions */);

    PostCSS Custom Properties 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 Properties and properties using custom properties should be preserved in their original form. By default, both of these are preserved.

    postcssCustomProperties({
      preserve: false
    });
    :root {
      --color: red;
    }
    
    h1 {
      color: var(--color);
    }
    
    /* becomes */
    
    h1 {
      color: red;
    }

    importFrom

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

    postcssCustomProperties({
      importFrom: 'path/to/file.css' // => :root { --color: red }
    });
    h1 {
      color: var(--color);
    }
    
    /* becomes */
    
    h1 {
      color: red;
    }

    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 Properties using the customProperties or custom-properties key.

    postcssCustomProperties({
      importFrom: [
        'path/to/file.css',   // :root { --color: red; }
        'and/then/this.js',   // module.exports = { customProperties: { '--color': 'red' } }
        'and/then/that.json', // { "custom-properties": { "--color": "red" } }
        {
          customProperties: { '--color': 'red' }
        },
        () => {
          const customProperties = { '--color': 'red' };
    
          return { customProperties };
        }
      ]
    });

    See example imports written in CSS, JS, and JSON.

    overrideImportFromWithRoot

    The overrideImportFromWithRoot option determines if properties added via importFrom are overridden by properties that exist in :root. Defaults to false.

    postcssCustomProperties({
      overrideImportFromWithRoot: true
    });

    exportTo

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

    postcssCustomProperties({
      exportTo: 'path/to/file.css' // :root { --color: red; }
    });

    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 Properties using the customProperties or custom-properties key.

    const cachedObject = { customProperties: {} };
    
    postcssCustomProperties({
      exportTo: [
        'path/to/file.css',   // :root { --color: red; }
        'and/then/this.js',   // module.exports = { customProperties: { '--color': 'red' } }
        'and/then/this.mjs',  // export const customProperties = { '--color': 'red' } }
        'and/then/that.json', // { "custom-properties": { "--color": "red" } }
        'and/then/that.scss', // $color: red;
        cachedObject,
        customProperties => {
          customProperties    // { '--color': 'red' }
        }
      ]
    });

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

    disableDeprecationNotice

    Silence the deprecation notice that is printed to the console when using importFrom or exportTo.

    "importFrom" and "exportTo" will be removed in a future version of postcss-custom-properties. Check the discussion on github for more details. https://github.com/csstools/postcss-plugins/discussions/192

    Install

    npm i postcss-custom-properties

    DownloadsWeekly Downloads

    7,481,070

    Version

    12.1.9

    License

    MIT

    Unpacked Size

    37.6 kB

    Total Files

    14

    Last publish

    Collaborators

    • alaguna
    • jonathantneal
    • moox
    • semigradsky