grunt-split-styles

Split a CSS file based on selectors. Useful for building old IE stylesheets for example.

Credit

Uses the excellent PostCSS for the actual CSS post-processing.

Getting Started

This plugin requires Grunt ~0.4.2

If you haven't used Grunt before, be sure to check out the Getting Started guide, as it explains how to create a Gruntfile as well as install and use Grunt plugins. Once you're familiar with that process, you may install this plugin with this command:

npm install grunt-split-styles --save-dev

Once the plugin has been installed, it may be enabled inside your Gruntfile with this line of JavaScript:

grunt.loadNpmTasks('grunt-split-styles');

The "split_styles" task

Overview

In your project's Gruntfile, add a section named split_styles to the data object passed into grunt.initConfig().

Options

options.pattern

Type: RegExp|Object

If a RegExp is specified then selectors matching this regular expression will be added to the output file.

Alternatively you can specify an object:

pattern: {
  match: /\.ie8/, // Required. See option.pattern.match below.
  matchParent: false // Optional. See options.pattern.matchParent below.
}

options.pattern.match

Type: RegExp

If a RegExp then selectors matching this regular expression will be added to the output file.

options.pattern.matchParent

Type: Boolean Default: false

If true then a declaration's parent media node will be matched along with the declaration itself.

For example when matching a pattern such as /^\.rtl/ against the following:

@media screen and (min-width: 50em) {
    .rtl .thing {
        color: red;
    }

   .another .thing {
        color: blue;
    }
}

Yields:

@media screen and (min-width: 50em) {
    .rtl .thing {
        color: red;
    }
}

options.output

Type: String

Optional new CSS file to copy the matching rulesets to.

options.remove

Type: Boolean Default value: true

Whether or not to remove the matching rulesets from the original stylesheet.

options.mediaPattern

Type: RegExp

@media rulesets matching this regular expression will be copied into the new stylesheet

options.mediaPatternUnwrap

Type: Boolean Default value: false

If true, only the child declarations of a matched @media rule will be extracted.

For example if your options are:

options: {
  output: 'media-children.css',
  mediaPattern: /min-width: (\d+)em/,
  mediaPatternUnwrap: true
}

And you apply it to the following:

@media screen and (min-width: 50em) {
    .rtl .thing {
        color: red;
    }

   .another .thing {
        color: blue;
    }
}

will extract:

.rtl .thing {
    color: red;
}

.another .thing {
    color: blue;
}

Usage Examples

Splitting IE styles into their own stylesheet

Here we take an input: style.css and extract the rules whose selectors start with .ie6, .ie7 or .ie8 into their own stylesheet styles-ie.css.

By default, the matching rules are removed from style.css.

grunt.initConfig({
  split_styles: {
    ie: {
      options: {
        pattern: /\.ie[6|7|8]/,
        output: 'style-ie.css'
      },
      files: {
        '<%= pkg.theme.path %>/style.css': '<%= pkg.theme.path %>/style.css'
      }
    }
  }
});

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.

Release History

• 2014-02-26 v0.3.0

  • Made 'output' optional (default false). Props @spacedawwwg.
  • Fixed 'matchParent' option ignoring rules without parent. Props @spacedawwwg.

• 2014-02-25 v0.2.0

  • Add option to match parent nodes of declarations.
  • Add option to unwrap declarations of matched @media nodes.
  • Add some basic tests.

• 2014-02-16 v0.1.0 Initial Release.