PostCSS loader for webpack to postprocesses your CSS with PostCSS plugins.
Set postcss section in webpack config:
var autoprefixer = require('autoprefixer-core');
var csswring = require('csswring');
module.exports = {
module: {
loaders: [
{
test: /\.css$/,
loader: "style-loader!css-loader!postcss-loader"
}
]
},
postcss: function {
return [autoprefixer, csswring];
}
}Now your CSS files requirements will be processed by selected PostCSS plugins:
var css = require('./file.css');
// => CSS after Autoprefixer and CSSWringNote that the context of this function
module.exports = {
...
postcss: function {
return [autoprefixer, csswring];
}
}will be set to the webpack loader-context. If there is the need, this will let you access to webpack loaders API.
If you want to process different styles by different PostCSS plugins you can
define plugin packs in postcss section and use them by ?pack=name parameter.
module.exports = {
module: {
loaders: [
{
test: /\.docs\.css$/,
loader: "style-loader!css-loader!postcss-loader?pack=cleaner"
},
{
test: /\.css$/,
loader: "style-loader!css-loader!postcss-loader"
}
]
},
postcss: function () {
return {
defaults: [autoprefixer, csswring],
cleaner: [autoprefixer({ browsers: [] })]
};
}
}When using postcss-import plugin, you may want to tell webpack about
dependencies coming from your @import directives.
For example: in watch mode, to enable recompile on change.
Since the function in postcss section is executed with the webpack loader-context, we can use the postcss-import callback onImport to tell webpack what files need to be watched.
var cssimport = require('postcss-import');
var autoprefixer = require('autoprefixer-core');
module.exports = {
module: {
loaders: [
{
test: /\.css$/,
loader: "style-loader!css-loader!postcss-loader"
}
]
},
postcss: function () {
// The context of this function is the webpack loader-context
// see: http://webpack.github.io/docs/loaders.html#loader-context
return [
cssimport({
// see postcss-import docs to learn about onImport callback
// https://github.com/postcss/postcss-import
onImport: function (files) {
files.forEach(this.addDependency);
}.bind(this)
}),
autoprefixer
];
}
}If you add ?safe=1 to requirement, PostCSS will try to correct any syntax
error that it finds in the CSS. For example, it will parse a { as a {}.
var css = require('postcss?safe=1!./broken')