This plugin extract CSS into separate files. It creates a CSS file per JS file which contains CSS. It supports On-Demand-Loading of CSS and SourceMaps.
It builds on top of a new webpack v4 feature (module types) and requires webpack 4 to work.
Compared to the extract-text-webpack-plugin:
* Async loading
* No duplicate compilation (performance)
* Easier to use
* Specific to CSS
TODO:
* HMR support
### Configuration
**webpack.config.js**
```js
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
module.exports = {
plugins: [
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// both options are optional
filename: "[name].css",
chunkFilename: "[id].css"
})
],
module: {
rules: [
{
test: /\.css$/,
use: [
MiniCssExtractPlugin.loader,
"css-loader"
]
}
]
}
}
```
### Minimizing For Production
While webpack 5 is likely to come with a CSS minimizer built-in, with webpack 4 you need to bring your own. To minify the output, use a plugin like [optimize-css-assets-webpack-plugin](https://github.com/NMFR/optimize-css-assets-webpack-plugin). Setting `optimization.minimizer` overrides the defaults provided by webpack, so make sure to also specify a JS minimizer:
**webpack.config.js**
```js
const UglifyJsPlugin = require("uglifyjs-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
cache: true,
parallel: true,
sourceMap: true // set to true if you want JS source maps
}),
new OptimizeCSSAssetsPlugin({})
]
},
plugins: [
new MiniCssExtractPlugin({
filename: "[name].css",
chunkFilename: "[id].css"
})
],
module: {
rules: [
{
test: /\.css$/,
use: [
MiniCssExtractPlugin.loader,
"css-loader"
]
}
]
}
}
```
### Features
#### Using preloaded or inlined CSS
The runtime code detects already added CSS via `` or `` tag.
This can be useful when injecting CSS on server-side for Server-Side-Rendering.
The `href` of the `` tag has to match the URL that will be used for loading the CSS chunk.
The `data-href` attribute can be used for `` and `` too.
When inlining CSS `data-href` must be used.
#### Extracting all CSS in a single file
Similar to what [extract-text-webpack-plugin](https://github.com/webpack-contrib/extract-text-webpack-plugin) does, the CSS
can be extracted in one CSS file using `optimization.splitChunks.cacheGroups`.
**webpack.config.js**
```js
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
module.exports = {
optimization: {
splitChunks: {
cacheGroups: {
styles: {
name: 'styles',
test: /\.css$/,
chunks: 'all',
enforce: true
}
}
}
},
plugins: [
new MiniCssExtractPlugin({
filename: "[name].css",
})
],
module: {
rules: [
{
test: /\.css$/,
use: [
MiniCssExtractPlugin.loader,
"css-loader"
]
}
]
}
}
```
Tobias Koppers