ui-lang-detector

Express.js middleware to detect UI language to be used to serve content.

As soon as you support a website that serves multilingual UI, you want to send the user your content in the language the user prefer. If this is a first-time visitor, you may want to try to guess the most appropriate language from the Accept-Language header. Later on, you will have a chance to ask the user what language they prefer and store this information with the user account data, or send a special cookie to the user agent.

This middleware extends the Request object with req.uilang property following these steps:

• First, check if the special cookie has come with the request. If so, ok - use it.

• If no cookie detected, analyze the Accept-Language header and choose the most preferable language.

• If nothing helps, use the provided default value.

All language codes are lowercased (e.g., en, en-us etc).

Installation

$ npm install ui-lang-detector --save

Usage example

const app = require('express')();
const uiLangDetector = require('ui-lang-detector');
 
// Set up options
const options = {
  cookieName: 'lang',
  defaultLang: 'en'
};
 
// Mount the middleware
app.use(uiLangDetector(options));
 
// Use on routes
app.get('/some_path', function (req, res) {
  const uiLanguage = req.uilang;
  // etc
});

API

Configuration options

Type: Object

options.cookieName

Type: String

Optional. The cookie name being used to store UI language. If omitted, cookies are not processed.

options.defaultLang

Type: String

Default language code to use.