i18next-http-middleware

import express from 'express'; import i18next from 'i18next'; import { LanguageDetector, handle } from 'i18next-http-middleware'; const app = express(); const PORT = process.env.PORT || 3000; // Initialize i18next with the language detector and some translations i18next.use(LanguageDetector).init({ preload: ['en', 'de', 'fr'], fallbackLng: 'en', debug: true, resources: { en: { translation: { welcome: 'Hello world!', greeting: 'Welcome to our internationalized app!', howAreYou: 'How are you?' } }, de: { translation: { welcome: 'Hallo Welt!', greeting: 'Willkommen in unserer internationalisierten App!', howAreYou: 'Wie geht es dir?' } }, fr: { translation: { welcome: 'Bonjour le monde!', greeting: 'Bienvenue dans notre application internationalisée!', howAreYou: 'Comment allez-vous?' } } } }); // Apply the i18next-http-middleware app.use(handle(i18next, { ignoreRoutes: ['/health'], // Example: ignore specific routes from i18n processing removeLngFromUrl: false // Set to true if language is part of the URL path (e.g., /en/home) })); // Example route demonstrating i18n usage app.get('/', (req, res) => { // Access i18n properties from the request object const language = req.language || 'en'; const translatedGreeting = req.t('greeting'); const translatedWelcome = req.t('welcome'); res.send(` <h1>${translatedWelcome}</h1> <p>${translatedGreeting}</p> <p>Current language: <strong>${language}</strong></p> <p>Detected languages: ${req.languages?.join(', ') || 'N/A'}</p> <p>Try going to <a href="/de">/de</a> or <a href="/fr">/fr</a></p> `); }); // Example route for a specific language path segment (if LanguageDetector is configured for path) app.get('/:lng', (req, res, next) => { // The middleware would have already set req.language based on the path if configured // For this example, we just render the root path again with the detected language if (['en', 'de', 'fr'].includes(req.params.lng)) { return res.redirect('/'); } next(); // Pass to next handler if not a language code }); // Health check route, ignored by i18n middleware app.get('/health', (req, res) => { res.send('OK'); }); app.listen(PORT, () => { console.log(`Server listening on http://localhost:${PORT}`); console.log('Test with:'); console.log(`- http://localhost:${PORT}/en`); console.log(`- http://localhost:${PORT}/de`); console.log(`- http://localhost:${PORT}/fr`); console.log(`- http://localhost:${PORT}?lng=fr`); console.log(`- curl -H "Accept-Language: de" http://localhost:${PORT}`); });