Mastering Internationalization in Remix JS

Internationalization (i18n) is a crucial aspect of modern web development, allowing your application to reach a global audience. In this guide, we'll explore how to implement internationalization in Remix JS, enabling your app to support multiple languages and locales.

Understanding Internationalization in Remix

Remix doesn't have built-in internationalization support, but it provides powerful tools and conventions that make implementing i18n straightforward. We'll use a combination of Remix features and popular i18n libraries to create a robust multilingual setup.

Setting Up the Project

First, let's set up a new Remix project and install the necessary dependencies:


npx create-remix@latest my-i18n-app
cd my-i18n-app
npm install i18next react-i18next i18next-browser-languagedetector

We'll use i18next as our main internationalization library, along with react-i18next for React bindings and i18next-browser-languagedetector for automatic language detection.

Configuring i18next

Create a new file app/i18n.js to configure i18next:


import i18n from 'i18next';
import { initReactI18next } from 'react-i18next';
import LanguageDetector from 'i18next-browser-languagedetector';

i18n
  .use(LanguageDetector)
  .use(initReactI18next)
  .init({
    resources: {
      en: {
        translation: {
          welcome: 'Welcome to my app!',
          greeting: 'Hello, {{name}}!',
        },
      },
      es: {
        translation: {
          welcome: '¡Bienvenido a mi aplicación!',
          greeting: '¡Hola, {{name}}!',
        },
      },
    },
    fallbackLng: 'en',
    interpolation: {
      escapeValue: false,
    },
  });

export default i18n;

This configuration sets up English and Spanish translations and enables language detection.

Integrating i18n with Remix

To integrate i18n with Remix, we need to wrap our app with the I18nextProvider. Update your app/root.jsx file:


import { json } from '@remix-run/node';
import {
  Links,
  LiveReload,
  Meta,
  Outlet,
  Scripts,
  ScrollRestoration,
  useLoaderData,
} from '@remix-run/react';
import { I18nextProvider } from 'react-i18next';
import i18n from './i18n';

export const loader = async ({ request }) => {
  const locale = request.headers.get('Accept-Language')?.split(',')[0] || 'en';
  return json({ locale });
};

export default function App() {
  const { locale } = useLoaderData();
  i18n.changeLanguage(locale);

  return (
    <I18nextProvider i18n={i18n}>
      <html lang={locale}>
        <head>
          <Meta />
          <Links />
        </head>
        <body>
          <Outlet />
          <ScrollRestoration />
          <Scripts />
          <LiveReload />
        </body>
      </html>
    </I18nextProvider>
  );
}

This setup detects the user's preferred language from the Accept-Language header and sets it in i18n.

Using Translations in Components

Now you can use translations in your components. Here's an example for app/routes/index.jsx:


import { useTranslation } from 'react-i18next';

export default function Index() {
  const { t } = useTranslation();

  return (
    <div>
      <h1>{t('welcome')}</h1>
      <p>{t('greeting', { name: 'John' })}</p>
    </div>
  );
}

Implementing Language Switching

To allow users to switch languages, you can create a language selector component:


import { useTranslation } from 'react-i18next';

export default function LanguageSelector() {
  const { i18n } = useTranslation();

  const changeLanguage = (lng) => {
    i18n.changeLanguage(lng);
  };

  return (
    <div>
      <button onClick={() => changeLanguage('en')}>English</button>
      <button onClick={() => changeLanguage('es')}>Español</button>
    </div>
  );
}

Add this component to your layout or navigation to enable language switching.

Route Conventions for Localization

Remix's file-based routing can be leveraged for localization. Create language-specific routes like this:


app/routes/
  ├── $lang/
  │   ├── index.jsx
  │   └── about.jsx
  ├── index.jsx
  └── about.jsx

In the $lang folder, you can create localized versions of your routes. The $lang parameter will capture the language code from the URL.

Handling Dynamic Content

For dynamic content that can't be pre-translated, you may need to fetch translations from an API. You can do this in your loader functions:


import { json } from '@remix-run/node';
import { useLoaderData, useTranslation } from '@remix-run/react';

export const loader = async ({ params }) => {
  const { lang } = params;
  const translations = await fetchTranslationsFromAPI(lang);
  return json({ translations });
};

export default function DynamicContent() {
  const { translations } = useLoaderData();
  const { t, i18n } = useTranslation();

  i18n.addResourceBundle(i18n.language, 'translation', translations, true, true);

  return (
    <div>
      <h1>{t('dynamicTitle')}</h1>
      <p>{t('dynamicContent')}</p>
    </div>
  );
}

This approach allows you to load translations dynamically and add them to i18next at runtime.

Performance Considerations

To optimize performance, consider the following:

Use code splitting to load language resources on demand.
Implement caching strategies for API-fetched translations.
Utilize Remix's server-side rendering capabilities to deliver localized content quickly.

By following these steps and best practices, you can create a fully internationalized Remix JS application that provides a seamless experience for users across different languages and locales.