postcss-mixins

    8.1.0 • Public • Published

    PostCSS Mixins

    PostCSS plugin for mixins.

    Note, that you must set this plugin before postcss-simple-vars and postcss-nested.

    @define-mixin icon $network, $color: blue {
        .icon.is-$(network) {
            color: $color;
            @mixin-content;
        }
        .icon.is-$(network):hover {
            color: white;
            background: $color;
        }
    }
    
    @mixin icon twitter {
        background: url(twt.png);
    }
    @mixin icon youtube, red {
        background: url(youtube.png);
    }
    .icon.is-twitter {
        color: blue;
        background: url(twt.png);
    }
    .icon.is-twitter:hover {
        color: white;
        background: blue;
    }
    .icon.is-youtube {
        color: red;
        background: url(youtube.png);
    }
    .icon.is-youtube:hover {
        color: white;
        background: red;
    }

    postcss-utilities collection is better for clearfix and other popular hacks. For simple cases you can use postcss-define-property.

    Sponsored by Evil Martians

    Usage

    Step 1: Install plugin:

    npm install --save-dev postcss postcss-mixins

    Step 2: Check you project for existed PostCSS config: postcss.config.js in the project root, "postcss" section in package.json or postcss in bundle config.

    If you do not use PostCSS, add it according to [official docs] and set this plugin in settings.

    Step 3: Add the plugin to plugins list:

    module.exports = {
      plugins: [
    +   require('postcss-mixins'),
        require('autoprefixer')
      ]
    }

    CSS Mixin

    Simple template defined directly in CSS to prevent repeating yourself.

    See postcss-simple-vars docs for arguments syntax.

    You can use it with postcss-nested plugin:

    @define-mixin icon $name {
        padding-left: 16px;
        &::after {
            content: "";
            background: url(/icons/$(name).png);
        }
    }
    
    .search {
        @mixin icon search;
    }

    Unlike Sass, PostCSS has no if or while statements. If you need some complicated logic, you should use function mixin.

    Function Mixin

    This type of mixin gives you full power of JavaScript. You can define this mixins in mixins option.

    This type is ideal for CSS hacks or business logic.

    Also you should use function mixin if you need to change property names in mixin, because postcss-simple-vars doesn’t support variables in properties yet.

    First argument will be @mixin node, that called this mixin. You can insert your declarations or rule before or after this node. Other arguments will be taken from at-rule parameters.

    See [PostCSS API] about nodes API.

    require('postcss-mixins')({
        mixins: {
            icons: function (mixin, dir) {
                fs.readdirSync('/images/' + dir).forEach(function (file) {
                    var icon = file.replace(/\.svg$/, '');
                    var rule = postcss.rule({ selector: '.icon.icon-' + icon });
                    rule.append({
                        prop:  'background',
                        value: 'url(' + dir + '/' + file + ')'
                    });
                    mixin.replaceWith(rule);
                });
            }
        }
    });
    @mixin icons signin;
    .icon.icon-back { background: url(signin/back.svg) }
    .icon.icon-secret { background: url(signin/secret.svg) }

    You can also return an object if you don’t want to create each node manually:

    require('postcss-mixins')({
        mixins: {
            image: function (mixin, path) {
                return {
                    '&': {
                        background: 'url(' + path + ')'
                    },
                    '@media (min-resolution: 120dpi)': {
                        '&': {
                            background: 'url(' + path + '@2x)'
                        }
                    }
                }
            }
        }
    });

    Mixin body will be in mixin.nodes:

    var postcss = require('postcss');
    
    require('postcss-mixins')({
        mixins: {
            hover: function (mixin) {
                let rule = postcss.rule({ selector: '&:hover, &.hover' });
                rule.append(mixin.nodes);
                mixin.replaceWith(rule);
            }
        }
    });

    Or you can use object instead of function:

    require('postcss-mixins')({
        mixins: {
            clearfix: {
                '&::after': {
                    content: '""',
                    display: 'table',
                    clear: 'both'
                }
            }
        }
    });

    Mixin Content

    @mixin-context at-rule will be replaced with mixin @mixin children. For exampel, CSS mixins:

    @define-mixin isIE {
        .isIE & {
            @mixin-content;
        }
    }

    or JS mixins:

    require('postcss-mixins')({
        mixins: {
            isIe: function () {
                '@mixin-content': {},
            }
        }
    });

    could be used like this:

    .foo {
        color: blue;
    
        @mixin isIE {
            color: red;
        }
    }
    
    // output
    .foo { color: blue; }
    .isIE .foo { color: red; }

    Migration from Sass

    If you need to use Sass and PostCSS mixins together (for example, while migration), you could use @add-mixin, instead of @mixin. Just put PostCSS after Sass.

    // Legacy SCSS
    @mixin old {
        …
    }
    @include old;
    
    // New code
    @define-mixin new {
        …
    }
    @add-mixin new;

    Options

    Call plugin function to set options:

    postcss([ require('postcss-mixins')({ mixins: {} }) ])

    mixins

    Type: Object

    Object of function mixins.

    mixinsDir

    Type: string|string[]

    Autoload all mixins from one or more dirs. Mixin name will be taken from file name.

    // gulpfile.js
    
    require('postcss-mixins')({
        mixinsDir: path.join(__dirname, 'mixins')
    })
    
    // mixins/clearfix.js
    
    module.exports = {
        '&::after': {
            content: '""',
            display: 'table',
            clear: 'both'
        }
    }
    
    // mixins/size.pcss
    
    @define-mixin size $size {
        width: $size;
        height: $size;
    }
    
    // mixins/circle.sss
    
    @define-mixin circle $size
      border-radius: 50%
      width: $size
      height: $size

    mixinsFiles

    Type: string|string[]

    Similar to mixinsDir; except, you can provide fast-glob syntax to target or not target specific files.

    require('postcss-mixins')({
        mixinsFiles: path.join(__dirname, 'mixins', '!(*.spec.js)')
    })

    silent

    Remove unknown mixins and do not throw a error. Default is false.

    Install

    npm i postcss-mixins

    DownloadsWeekly Downloads

    144,953

    Version

    8.1.0

    License

    MIT

    Unpacked Size

    14.6 kB

    Total Files

    4

    Last publish

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