@routup/i18n

Adds locale detection and translation to the routup pipeline. Built on ilingo — bring any Store (memory, filesystem, async loader, …) and the plugin handles per-request locale resolution and the translator factory.

Installation

npm install @routup/i18n ilingo

Quick start

import { Router, defineCoreHandler, serve } from 'routup';
import { MemoryStore } from 'ilingo';
import { i18n, useTranslator } from '@routup/i18n';

const store = new MemoryStore({
    data: {
        en: { app: { greeting: 'Hello, my name is {{name}}' } },
        de: { app: { greeting: 'Hallo, mein Name ist {{name}}' } },
    },
});

const router = new Router();

router.use(i18n({ store }));

router.get('/', defineCoreHandler((event) => {
    const t = useTranslator(event);
    return t({ group: 'app', key: 'greeting', data: { name: 'Peter' } });
}));

serve(router, { port: 3000 });

The middleware inspects each incoming request and selects a locale (defaulting to ilingo's resolver — typically Accept-Language or a configured query/cookie strategy). useTranslator(event) returns a translator pre-bound to that locale.

When to use it

• Multi-language API responses, error messages, or email bodies rendered server-side
• Centralizing translation files under one Store shared across the request pipeline
• Reusing existing ilingo stores (memory, filesystem, custom async loader)

Helpers

useTranslator

Returns a translator bound to the request's resolved locale.

import type { IRoutupEvent } from 'routup';
import type { Translator } from '@routup/i18n';

declare function useTranslator(event: IRoutupEvent): Translator;

const t = useTranslator(event);
const greeting = t({ group: 'app', key: 'greeting', data: { name: 'Peter' } });

For ilingo's Translator API (interpolation, fallback chains, plurals), see the ilingo documentation.