react-intl-extract-webpack-plugin

Webpack plugin to extract react-intl translations with suppport for on demand chunk loading per active locale during dynamic imports. Also supports HMR and SSR.

npm i @react-app/react-intl-extract-webpack-plugin

Usage:

• get familiar with react-intl ecosystem

• add to babel-loader's options:

  options: {
      ...
      plugins: [
          ...
          '@react-app/react-intl-extract-webpack-plugin/babel',
          ...
      ]
      metadataSubscribers: [ReactIntlExtractWebpackPlugin.BABEL_LOADER_METADATA_SUBSCRIBER],
      ...
  },

• add plugin to webpack's config:

  const ReactIntlExtractWebpackPlugin = require('@react-app/react-intl-extract-webpack-plugin');
  
      plugins: [
          ...
          new ReactIntlExtractWebpackPlugin(),
          ...
      ]

• create translations.js file in root of your project's folder (cwd for webpack)

  // type Descriptor = {
  //    id: string,
  //    defaultMessage?: string,
  //    description?: string,
  // }
  
  // type Translations = {
  //    [locale: string]: {
  //        [id: string]: string,
  //    },
  // } 
  
  module.exports = (descriptors: Iterator<Descriptor>) => {
      /// your code to resolve descriptor translations
      /// you can even query/update your SQL database or read json file
      return Promise(translations) as Promise<Translations>;
  }

• add this code in userland before ReactDOM.render:

    import React from 'react';
    import ReactDOM from 'react-dom';
    import {IntlProvider, addLocaleData} from 'react-intl';
    import initialize from '@react-app/react-intl-extract-webpack-plugin/browser';
  
    import App from './App';
  
    const chunkLoader = initialize();
    const locale = 'sk'; // <- you can resolve this dynamically
  
    Promise.all([ 
        // tip: use webpackImport magic comment to bundle only languages you need
        import(/* webpackChunkName: "[request]" */ `react-intl/locale-data/${locale}`),
        chunkLoader.setLocale(locale),
    ])
        .then(([locale]) => {
            addLocaleData(locale.default);
            ReactDOM.render(<IntlProvider messages={chunkLoader.messages} locale={chunkLoader.locale}><App /></IntlProvider>, document.getElementById('root'));
        })
  

Note: This plugin uses it's own babel plugin which is a fork of react-intl-babel-plugin. It does not enforce defaultMessage field to save bundle size when you want to dynamically switch between locales at the start of the app.

Note: react-intl's addLocaleData is not managed by chunk loader intentionally.

When new chunk is requested with import(...), chunkLoader loads all missing translations for current active locale using patched webpack's internals

It is possible to dynamically change locale after bootstrap, chunkLoader stores already loaded webpack chunks and loads them all for newly set locale:

    Promise.all([
        import(/* webpackChunkName: "[request]" */ `react-intl/locale-data/${locale}`),
        chunkLoader.setLocale(locale),
    ]).then(() => {
        this.setState({
            locale: chunkLoader.locale,
            messages: chunkLoader.messages,
        }); // <- use this state as <IntlProvider> props, you will need to also use key={locale} hack to re-render everything until react-intl start's to use new React Context API
    })

For SSR you can use react-intl-messages.[suffix].json with all translations, manifest file react-intl-manifest.[suffix].json and react-intl-chunkgroup-messages.[suffix].json which are generated during build.

Webpack plugin also accepts options (defaults are):

{
    development: process.env.NODE_ENV === 'development',
    outputPath: 'static/intl/',
    suffix: '',
}