Internationalization

next-forge includes a powerful internationalization package that enables you to add multiple language support to your application with minimal configuration. The package handles language detection, routing, and content management through a dictionary-based approach.

How it works

The internationalization system is built on Next.js Internationalization's routing system and Languine's translation system.

It's configured by default for the web package to:

1. Detect the user's preferred language through browser headers
2. Route users to language-specific paths (e.g., /en/about, /fr/about)
3. Serve content from language-specific dictionaries

The package handles language detection and matching, ensuring users see content in their preferred language when available.

Setup

To enable automatic translations, simply create a .env file in the internationalization package and set the LANGUINE_PROJECT_ID environment variable.

LANGUINE_PROJECT_ID="your-project-id"

Configuration

The internationalization package is configured through a languine.json file that defines:

• Source locale (e.g., en)
• Target locales (e.g., ["es", "de"])
• Dictionary file locations

Dictionary Structure

Dictionaries are TypeScript files that export strongly-typed content for each supported language. The type system ensures consistency across translations:

import type { Dictionary } from '@repo/internationalization';

const dictionary: Dictionary = {};

export default dictionary;

There is no need to create a dictionary for any non-source locale, as Languine will automatically generate the translations for you.

Usage

Translating

To translate your application, you can run the following command:

bun run translate

This will translate all of the content in your application and save the translations to the dictionaries folder.

Frontend

To use the internationalization package, you need to:

1. Maintain a dictionary for your source locale.
2. Import the dictionary into your application.
3. Use the dictionary to render content.

You can find an example of a dictionary in the web package:

import { getDictionary } from '@repo/internationalization';

type HomeProps = {
  params: Promise<{
    locale: string;
  }>;
};

const Home = async ({ params }: HomeProps) => {
  const { locale } = await params;
  const dictionary = await getDictionary(locale);

  // ...
};

You can change the locale of the application by changing the locale parameter in the URL. For example, https://example.com/en/about will render the about page in English.

We've already configured the web package with a language switcher, so you don't need to worry about it.

Middleware

The internationalization package also includes a middleware component that automatically detects the user's language and routes them to the appropriate language-specific page.

This has already been configured for the web package, so you don't need to worry about it.

import { createNEMO } from '@rescale/nemo';
import { internationalizationMiddleware } from '@repo/internationalization';

// The i18n middleware is composed into the middleware chain
// alongside auth and security middleware using createNEMO:
const composed = createNEMO([...], {
  before: [internationalizationMiddleware, arcjetMiddleware],
});