express-lingua | An i18n middleware for the Express.js framework | Runtime Evironment library

Using lingua comes down with four simple steps:.
Grab lingua var express = require('express'), lingua = require('lingua'); ... // Express init code goes here ... // Express app configuration code and lingua init. app.configure(function() { ... app.set('views', __dirname + '/views'); app.set('view engine', 'ejs'); // Lingua configuration app.use(lingua(app, { defaultLocale: 'en', path: __dirname + '/i18n' })); app.use(express.bodyParser()); app.use(express.methodOverride()); app.use(express.static(__dirname + '/public')); app.use(app.router); ... }); Note: Please ensure that the call: "app.use(app.router);" is the last entry in your configuration section.
Create i18n resource files - Note that you have to create a resource file for your default language. (In this example: './i18n/en.json' and './i18n/de-de.json'). // en.json { "title": "Hello World", "content": { "description": "A little description." } } // de-de.json { "title": "Hallo Welt", "content": { "description": "Eine kleine Beschreibung." } }
a. Use lingua in your views - Static output - Note that the syntax depends on your template engine. In this example it is: ejs and the request comes from a browser which sends 'en' with the HTTP request header. <h1><%= lingua.title %></h1> <!-- out: <h1>Hello World</h1> --> <p><%= lingua.content.description %></h1> <!-- out: <p>A little description.</p> --> b. Use lingua in your views - Dynamic output - Sometimes it is necessary to handle dynamic data within your express route and pass it to the template. What if your i18n resource includes placeholders ("{key}") within a string where you can put in your dynamic data? Well, it is possible. First of all, look at this i18n resource file: // de.json { "greeting": "Hallo {name}. Dieser Schlüssel {code} wurde für Dich generiert." } Now it is possible to transfer an object from your route into your template: app.get('/', function(req, res) { var names = ['Sarah', 'Thomas', 'Claudia']; res.render('index', { person: { name: names[Math.floor(Math.random()*names.length)], code: Math.round(Math.random()*100) } }); }); And finally you can execute the i18n resource (yes, you can execute it (: ) and pass your data model to this function: <p><%= lingua.greeting(person) %></p> Note: Every i18n resource which contains placeholders like in the example above is a function after you've started the application.
Let the user select a language - Note that the user's selection is persisted within a cookie. This is an optional step. If you want to let lingua determine the user language from the browser configuration then leave this step out. Anyway, this is a very handy feature for switching the language by a user decision. <a href="?language=de-DE">de-DE</a> <a href="?language=en-US">en-US</a> You can configure lingua in order to change the name of this parameter. // Express app configuration code and lingua init. app.configure(function() { ... // Lingua configuration app.use(lingua(app, { defaultLocale: 'en', path: __dirname + '/i18n', storageKey: 'lang' // http://domain.tld/?lang=de })); ... }); The cookie lingua uses expires in one year, and includes the httpOnly flag to prevent clientside access from Javascript. You can override these settings by providing a cookieOptions key during configuration. // Express app configuration code and lingua init. app.configure(function() { ... // Lingua configuration app.use(lingua(app, { defaultLocale: 'en', path: __dirname + '/i18n', storageKey: 'lang', // http://domain.tld/?lang=de cookieOptions: { domain: '.domain.tld', // to allow subdomains access to the same cookie, for instance path: '/blog', // to restrict the language cookie to a path httpOnly: false, // if you need access to this cookie from javascript on the client expires: new Date(Date.now() + 24 * 60 * 60 * 1000), // expire in 1 day instead of 1 year secure: true // for serving over https } })); ... });