rsnext/examples/with-react-intl/README.md

Example app with React Intl

This example app shows how to integrate React Intl with Next.

How to use

Using create-next-app

Execute create-next-app with npm or Yarn to bootstrap the example:

npm init next-app --example with-react-intl with-react-intl-app
# or
yarn create next-app --example with-react-intl with-react-intl-app

Download manually

Download the example:

curl https://codeload.github.com/vercel/next.js/tar.gz/canary | tar -xz --strip=2 next.js-canary/examples/with-react-intl
cd with-react-intl

Install it and run:

npm install
npm run dev
# or
yarn
yarn dev

Deploy it to the cloud with Vercel (Documentation).

Features of this example app

• Server-side language negotiation
• React Intl locale data loading via pages/_document.js customization
• React Intl integration with custom App component
• <IntlProvider> creation with locale, messages props
• Default message extraction via babel-plugin-react-intl integration
• Translation management via build script and customized Next server

Translation Management

This app stores translations and default strings in the lang/ dir. This dir has .messages/ subdir which is where React Intl's Babel plugin outputs the default messages it extracts from the source code. The default messages (en.json in this example app) is also generated by the build script. This file can then be sent to a translation service to perform localization for the other locales the app should support.

The translated messages files that exist at lang/*.json are only used during production, and are automatically provided to the <IntlProvider>. During development the defaultMessages defined in the source code are used. To prepare the example app for localization and production run the build script and start the server in production mode:

$ npm run build
$ npm start

You can then switch your browser's language preferences to French and refresh the page to see the UI update accordingly.

FormattedHTMLMessage support (react-intl pre-v4)

Out of the box, this example does not support the use of the FormattedHTMLMessage component on the server due to DOMParser not being present in a Node environment. This functionality is deprecated and has been removed as of react-intl 4.0 If you still want to enable this feature, you should install a DOMParser implementation (e.g. xmldom or jsdom) and enable the polyfill in server.js:

// Polyfill Node with `DOMParser` required by formatjs.
// See: https://github.com/zeit/next.js/issues/10533
const { DOMParser } = require('xmldom')
global.DOMParser = DOMParser

Transpile react-intl

According to react-intl docs, react-intl and its underlying libraries must be transpiled to support older browsers (eg IE11). This is done by next-transpile-modules in next.config.js.