express-simple-locale

A simple Express middleware to guess the short-locale of a user. It then saves the found locale on the request for further usage.

It tries, in that order:

1. The locale query parameter.
2. The cookie specified by cookieName option.
3. The first entry of accept-language header.
4. The acceptedLanguages key from the request.
5. The hostname.locale nested key from the request.

When found, the locale is split on spaces, hyphens and underscores so only the first part gets returned (en_GB -> en).

Install

npm i --save express-simple-locale

Options

Name	Type	Default	Description
key	String	locale	the key to save locale to on the request
supportedLocales	String[]	[]	available locales for the app
defaultLocale	String	en	locale to fallback to
cookieName	String	locale	cookie to try getting the locale from
queryParams	String|String[]	['locale']	the query parameter(s) to look the locale from

Example

import locale from 'express-simple-locale'

const localeMiddlewareOptions = {
  key: 'userLocale',
  supportedLocales: ['en', 'fr', 'it', 'es', 'de'],
  defaultLocale: 'en',
  cookieName: 'c00ki3z',
  queryParams: ['locale', 'lang']
}

express()
  .use(locale(localeMiddlewareOptions))
  .use((request, response, next) => {
    // request.userLocale
  })