window not defined error when using extract-text-webpack-plugin React

I'm using webpack to build my react components and I'm trying to use the extract-text-webpack-plugin to separate my css from my generated js file. However, when I attempt to build the component I get the following error: Module build failed: ReferenceError: window is not defined.

My webpack.config.js file looks like this:

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


module.exports = {
entry: {
MainComponent: './src/main.js'
},
output: {
libraryTarget: 'var',
library: 'MainComponent',
path: './build',
filename: '[name].js'
},
module: {
loaders: [{
test: /\.css$/, loader: ExtractTextPlugin.extract('style-loader!css-loader')
}]
},
plugins: [
new ExtractTextPlugin('styles.css')
]
}
33440 次浏览
小开

You may want to use style-loader as a before argument in extract function.

Here's the native implementation:

    ExtractTextPlugin.extract = function(before, loader, options) {
if(typeof loader === "string") {
return [
ExtractTextPlugin.loader(mergeOptions({omit: before.split("!").length, extract: true, remove: true}, options)),
before,
loader
].join("!");
} else {
options = loader;
loader = before;
return [
ExtractTextPlugin.loader(mergeOptions({remove: true}, options)),
loader
].join("!");
}
};

So basicaly what you need to do is:

{
test: /\.sass$/,
exclude: /node_modules/,
loader: ExtractTextPlugin.extract('style-loader', 'css!sass?indentedSyntax=true&sourceMap=true')
},

if you for example use sass.

小开

I figured out the solution to my problem:

Instead of piping the loaders into one another (ExtractTextPlugin.extract('style-loader!css-loader')), you have to pass in the each loader as a separate parameter: ExtractTextWebpackPlugin.extract('style-loader', 'css-loader')

小开

Didn't see an explanation of the cause so I have posted this answer here.

From https://github.com/webpack/extract-text-webpack-plugin#api

ExtractTextPlugin.extract([notExtractLoader], loader, [options]) Creates an extracting loader from an existing loader.

notExtractLoader (optional) the loader(s) that should be used when the css is not extracted (i.e. in an > additional chunk when allChunks: false)

loader the loader(s) that should be used for converting the resource to a css exporting module.

options

publicPath override the publicPath setting for this loader.

The #extract method should receive a loader that outputs css. What was happening was that it was receiving a style-loader which outputs javascript code, which is intended to be injected into a webpage. This code would try to access window.

You should not pass a loader string with style to #extract. However...if you set allChunks=false, then it will not build CSS files for non-initial chunks. Therefore it needs to know what loader to use to inject into the page.

Tip: Webpack is a tool that really needs to be understood in-depth or you can run into lots of strange issues.

小开

Webpack 2

If you're using Webpack 2, this variation works:

    rules: [{
test: /\.css$/,
exclude: '/node_modules/',
use: ExtractTextPlugin.extract({
fallback: [{
loader: 'style-loader',
}],
use: [{
loader: 'css-loader',
options: {
modules: true,
localIdentName: '[name]__[local]--[hash:base64:5]',
},
}, {
loader: 'postcss-loader',
}],
}),
}]

The new extract method no longer takes three arguments, and is listed as a breaking change when moving from V1 to V2.

https://webpack.js.org/guides/migrating/#extracttextwebpackplugin-breaking-change


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