postcss-custom-properties-nested
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    12.0.0 • Public • Published

    PostCSS Custom Properties PostCSS

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    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 to process your CSS:

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

    Or use it 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.

    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" } }
        cachedObject,
        customProperties => {
          customProperties    // { '--color': 'red' }
        }
      ]
    });

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

    Install

    npm i postcss-custom-properties-nested

    DownloadsWeekly Downloads

    2

    Version

    12.0.0

    License

    MIT

    Unpacked Size

    54.3 kB

    Total Files

    7

    Last publish

    Collaborators

    • olly12mm