@calebmer/extract-text-webpack-plugin

Extract Text Plugin

Extract text from a bundle, or bundles, into a separate file.

Install

# for webpack 3
npm install --save-dev extract-text-webpack-plugin
# for webpack 2
npm install --save-dev extract-text-webpack-plugin@2.1.2
# for webpack 1
npm install --save-dev extract-text-webpack-plugin@1.0.1

Usage

:warning: For webpack v1, see the README in the webpack-1 branch.

const ExtractTextPlugin = require("extract-text-webpack-plugin");

module.exports = {
  module: {
    rules: [
      {
        test: /\.css$/,
        use: ExtractTextPlugin.extract({
          fallback: "style-loader",
          use: "css-loader"
        })
      }
    ]
  },
  plugins: [
    new ExtractTextPlugin("styles.css"),
  ]
}

It moves all the required *.css modules in entry chunks into a separate CSS file. So your styles are no longer inlined into the JS bundle, but in a separate CSS file (styles.css). If your total stylesheet volume is big, it will be faster because the CSS bundle is loaded in parallel to the JS bundle.

Advantages	Caveats
Fewer style tags (older IE has a limit)	Additional HTTP request
CSS SourceMap (with devtool: "source-map" and extract-text-webpack-plugin?sourceMap)	Longer compilation time
CSS requested in parallel	No runtime public path modification
CSS cached separate	No Hot Module Replacement
Faster runtime (less code and DOM operations)	...

Options

new ExtractTextPlugin(options: filename | object)

Name	Type	Description
id	{String}	Unique ident for this plugin instance. (For advanced usage only, by default automatically generated)
filename	{String|Function}	Name of the result file. May contain [name], [id] and [contenthash]
allChunks	{Boolean}	Extract from all additional chunks too (by default it extracts only from the initial chunk(s)) When using optimization.splitChunks and there are extracted chunks (from ExtractTextPlugin.extract) in the commons chunk, allChunks must be set to true
disable	{Boolean}	Disables the plugin
ignoreOrder	{Boolean}	Disables order check (useful for CSS Modules!), false by default

• [name] name of the chunk
• [id] number of the chunk
• [contenthash] hash of the content of the extracted file
• [<hashType>:contenthash:<digestType>:<length>] optionally you can configure
  • other hashTypes, e.g. sha1, md5, sha256, sha512
  • other digestTypes, e.g. hex, base26, base32, base36, base49, base52, base58, base62, base64
  • and length, the length of the hash in chars

:warning: ExtractTextPlugin generates a file per entry, so you must use [name], [id] or [contenthash] when using multiple entries.

#extract

ExtractTextPlugin.extract(options: loader | object)

Creates an extracting loader from an existing loader. Supports loaders of type { loader: [name]-loader -> {String}, options: {} -> {Object} }.

Name	Type	Description
options.use	{String}/{Array}/{Object}	Loader(s) that should be used for converting the resource to a CSS exporting module (required)
options.fallback	{String}/{Array}/{Object}	loader(e.g 'style-loader') that should be used when the CSS is not extracted (i.e. in an additional chunk when allChunks: false)
options.publicPath	{String}	Override the publicPath setting for this loader

Multiple Instances

There is also an extract function on the instance. You should use this if you have more than one instance of ExtractTextPlugin.

const ExtractTextPlugin = require('extract-text-webpack-plugin');

// Create multiple instances
const extractCSS = new ExtractTextPlugin('stylesheets/[name]-one.css');
const extractLESS = new ExtractTextPlugin('stylesheets/[name]-two.css');

module.exports = {
  module: {
    rules: [
      {
        test: /\.css$/,
        use: extractCSS.extract([ 'css-loader', 'postcss-loader' ])
      },
      {
        test: /\.less$/i,
        use: extractLESS.extract([ 'css-loader', 'less-loader' ])
      },
    ]
  },
  plugins: [
    extractCSS,
    extractLESS
  ]
};

Extracting Sass or LESS

The configuration is the same, switch out sass-loader for less-loader when necessary.

const ExtractTextPlugin = require('extract-text-webpack-plugin');

module.exports = {
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: ExtractTextPlugin.extract({
          fallback: 'style-loader',
          use: ['css-loader', 'sass-loader']
        })
      }
    ]
  },
  plugins: [
    new ExtractTextPlugin('style.css')
    //if you want to pass in options, you can do so:
    //new ExtractTextPlugin({
    //  filename: 'style.css'
    //})
  ]
}

url() Resolving

If you are finding that urls are not resolving properly when you run webpack. You can expand your loader functionality with options. The url: false property allows your paths resolved without any changes.

const ExtractTextPlugin = require('extract-text-webpack-plugin');

module.exports = {
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: ExtractTextPlugin.extract({
          fallback: 'style-loader',
          use: [
            {
                loader: 'css-loader',
                options: {
                    // If you are having trouble with urls not resolving add this setting.
                    // See https://github.com/webpack-contrib/css-loader#url
                    url: false,
                    minimize: true,
                    sourceMap: true
                }
            }, 
            {
                loader: 'sass-loader',
                options: {
                    sourceMap: true
                }
            }
          ]
        })
      }
    ]
  }
}

Modify filename

filename parameter could be Function. It passes getPath to process the format like css/[name].css and returns the real file name, css/js/a.css. You can replace css/js with css then you will get the new path css/a.css.

entry: {
  'js/a': "./a"
},
plugins: [
  new ExtractTextPlugin({
    filename:  (getPath) => {
      return getPath('css/[name].css').replace('css/js', 'css');
    },
    allChunks: true
  })
]

Maintainers

Juho Vepsäläinen

Joshua Wiens

Kees Kluskens

Sean Larkin