with-react-intl

Internationalize React apps with a simple HOC and retrieve localized message either by a Component (with yahoo/react-intl) or as a String

Internationalize React apps with react-intl and intl-messageformat with a simple HOC - withReactIntl. From react-intl we can load locale messages through a Component. With the use of intl-messageformat we can load locale messages as a String.

Features:

• Internationalize with one simple HOC
• Figure the user locale from the browser or from the user input
• Inject props: locale and setLocale, to get and set locale manually
• Get formatted message as a String
• Load and add locale data and messages dynamically, no need for hard-coding anything

TL;DR steps:

1. Add ${locale}.js files to translations directory
2. Wrap App with withReactIntl HOC Done!

Install

npm i react-intl with-react-intl --save

Or:

yarn add react-intl with-react-intl

Step 1 - Create translations files

Create js files containing an object with all the translated messages. requirements:

• files should be *.js
• files should be at the directory ROOT/translations/
• files should be named after the locale you want (e.g. en.js, es.js)
• files should contain an exported object called translation example:

// en.js
const NUM_OF_PERSONS = `{numOfPersons, plural, 
    =undefined {0} 
    =0 {0}
    one {, 1 Person} 
    other {, # Persons} 
}`
export const translation = {
    welcome: `Hello {name}`,
    CommentList: {
        numberOfComments: `There {numOfComments, plural, one {is one comment} other {are {numOfComments} comments}}`,
        numberOfPersons: `Total: ${NUM_OF_PERSONS}`
    }
    // ...
}

recommended conventions:

• message ids that are not generic and should be used only in a specific component (aka numberOfComments in CommentList) should be nested in an id with the name of the component (aka CommentList PascalCase).
• message ids should not start with an Uppercase, unless it is a component, obviously for confusion reasons.

Step 2 - Wrap your App

Wrap your app component with the HOC - withReactIntl

// App.js
import React from 'react'
import withReactIntl from 'with-react-intl'

const App = () =>
  <div>
    // ...
  </div>

export default withReactIntl(App)

Start coding

Now you can simply get a locale message, either as a String or as a Component: example for getting a Component:

import { FormattedMessage } from 'react-intl'

const FormattedComponent = () => 
    <FormattedMessage id='CommentList.numberOfPersons' values={{ numOfPersons: 8 }} />

example for getting a String:

import { formatIntlLiteral } from 'with-react-intl'

const formattedString = formatIntlLiteral({ id: 'CommentList.numberOfPersons', values: { numOfPersons: 8 } })

Extra details

• locales are loaded dynamically from react-intl/locale-data/${locale} with addLocaleData from react-intl
• supported locales from your translations directory are also loaded dynamically
• locale is resolved from the browser by navigator.language and gets the locale without region code (i.e. 'fr-Fr' is resolved to 'fr')
• ${locale}.js files are flatten with { flatten } from 'flat'
• formatIntlLiteral has the following fallback algorithm:
  1. Lookup and format the translated message at id, passed to <IntlProvider> with values.
  2. Fallback to formatting the defaultMessage.
  3. Fallback to source of translated message at id.
  4. Fallback to the literal message id.
• how locale is defined?
  • Lookup for user's locale input
  • Fallback to navigator.language (user preferred language in the browser)
  • Fallback to user's defaultLocale input
  • Fallback to "en"