Isomorphic CSS style loader for Webpack
An alternative CSS style loader, which works similarly to style-loader, but is optimized for isomorphic apps. In addition to what style-loader provides, it allow to render critical path CSS during server-side rendering (SSR), by adding two helper methods on to the
styles
object -._insertCss()
(injects CSS into the DOM) and._getCss()
(returns CSS string).
See getting started | changelog | Join #react-starter-kit chat room on Gitter to stay up to date
$ npm install isomorphic-style-loader --save-dev
{
module: {
loaders: [
{
test: /\.scss$/,
loaders: [
'isomorphic-style-loader',
'css-loader?modules&localIdentName=[name]_[local]_[hash:base64:3]',
'postcss-loader'
]
}
]
}
}
Note: Configuration is the same for both client-side and server-side bundles.
// MyComponent.scss
.root { padding: 10px; }
.title { color: red; }
// MyComponent.js
import React, { PropTypes } from 'react';
import withStyles from 'isomorphic-style-loader/lib/withStyles';
import s from './MyComponent.scss';
function MyComponent(props, context) {
return (
<div className={s.root}>
<h1 className={s.title}>Hello, world!</h1>
</div>
);
}
export default withStyles(s)(MyComponent); // <--
P.S.: It works great with CSS Modules!
Just decorate your React component with the withStyles
higher-order component, and pass a function to your React app via insertCss
context variable (see React's context API)
that either calls styles._insertCss()
on a client, or styles._getCss()
on the server. See server-side rendering example below:
import express from 'express';
import ReactDOM from 'react-dom';
import router from './router.js'; // <-- isomorphic router, see react-starter-kit for example
const server = express();
const port = process.env.PORT || 3000;
// Server-side rendering of the React app
server.get('*', (req, res, next) =>
const css = new Set(); // CSS for all rendered React components
const context = { insertCss: (...styles) => styles.forEach(style => css.add(style._getCss())); };
router.dispatch({ ...req, context }).then((component, state) => {
const body = ReactDOM.renderToString(component);
const html = `<!doctype html>
<html>
<head>
<script async src="/client.js"></script>
<style type="text/css">${[...css].join('')}</style>
</head>
<body>
<div id="root">${body}</div>
</body>
</html>`;
res.status(state.statusCode).send(html);
}).catch(next);
});
server.listen(port, () => {
console.log(`Node.js app is running at http://localhost:${port}/`);
});
It should generate an HTML output similar to this one:
<html>
<head>
<title>My Application</title>
<script async src="/client.js"></script>
<style type="text/css">
.MyComponent_root_Hi8 { padding: 10px; }
.MyComponent_title_e9Q { color: red; }
</style>
</head>
<body>
<div id="root">
<div class="MyComponent_root_Hi8" data-reactid=".cttboum80" data-react-checksum="564584530">
<h1 class="MyComponent_title_e9Q" data-reactid=".cttboum80.0">Hello, World!</h1>
</div>
</div>
</body>
</html>
Regardless of how many styles components there are in the app.js
bundle,
only critical CSS is going to be rendered on the server inside the <head>
section of HTML document. Critical CSS is what actually used on the
requested web page, effectively dealing with FOUC
issue and improving client-side performance. CSS of the unmounted components
will be removed from the DOM.
You can activate hot module reload for style by setting the debug
option to true in your webpack
configuration. If you are using webpack 2, you need to supply it though the LoaderOptionsPlugin
because the debug
option has been removed.
♥ Isomorphic Style Loader? Help us keep it alive by donating funds to cover project expenses!
- React Starter Kit — Isomorphic web app boilerplate
- #react-starter-kit on Gitter
- @koistya on Codementor
The MIT License © 2015-2016 Kriasoft, LLC. All rights reserved.
Made with ♥ by Konstantin Tarkus (@koistya) and contributors