next-i18next

Next-i18next: Simplified Translation for Next.js Applications

Overview

Next-i18next is a powerful and easy-to-use library designed to facilitate the translation of Next.js applications. While Next.js does offer internationalized routing, it doesn't manage translation content. Next-i18next steps in to fill this gap, providing seamless integration of translation functionality with full support for server-side generation (SSG), server-side rendering (SSR), and multiple namespaces. Users only need to provide their translation content in JSON format, making it incredibly user-friendly.

Why Choose Next-i18next?

The library offers several compelling advantages:

• Ease of Setup and Usage: With a simple configuration process, developers can quickly get started.
• No Additional Dependencies: It streamlines internationalization without requiring extra libraries.
• Production-Ready: Full support for passing translations and configuration options to pages with SSG/SSR capabilities.

Functionality and Workflow

Configuration

To get started, create a next-i18next.config.js file at your project's root, informing the library about your default and supported locales. This setup ensures that all pages load the appropriate translations before rendering.

Core Components

The library uses a few essential components for its functionality:

• appWithTranslation: A high-order component (HOC) that wraps your custom _app file, integrating the I18nextProvider to manage all translation components globally.
• serverSideTranslations: An asynchronous function added to your getStaticProps or getServerSideProps in pages to load required translations and pass them as props.
• useTranslation: A hook for utilizing translation within your components. It abstracts complexity, allowing you to translate text using the t function provided by the hook.

Setting Up Next-i18next

Installation

You can easily install next-i18next alongside react-i18next and i18next:

yarn add next-i18next react-i18next i18next

Ensure react and next are already installed in your project.

Structuring Translation Content

Assuming a default file structure within the public/locales directory:

.
└── public
    └── locales
        ├── en
        │   └── common.json
        └── de
            └── common.json

You can configure custom paths with localePath and localeStructure within your initialization settings.

Configuring Sample Projects

Create a next-i18next.config.js file and include your desired configurations:

/** @type {import('next-i18next').UserConfig} */
module.exports = {
  i18n: {
    defaultLocale: 'en',
    locales: ['en', 'de'],
  },
}

And adjust your next.config.js to integrate next-i18next configurations:

const { i18n } = require('./next-i18next.config')

module.exports = {
  i18n,
}

Advanced Features

Namespace and Locale Dependencies

Optimize loading by splitting namespaces per page, reducing the payload size sent to clients. Pass an array of necessary namespaces to serverSideTranslations.

Additionally, load extra locales by providing an array of locales to serverSideTranslations, beyond the active one, for more flexible runtime translation needs.

Fallback and Client-Side Options

Define fallback locales to handle requests gracefully when translations are missing. Enable client-side translation loading using specific configurations for dynamic needs without hindering performance.

Customization and Extensibility

Next-i18next supports advanced custom configurations through the next-i18next.config.js file, enabling developers to tailor options to their application requirements. This also includes support for custom interpolation prefixes/suffixes and non-serializable configurations when using advanced plugins.

Conclusion

Next-i18next stands out by making internationalization straightforward and efficient for Next.js developers. Its seamless integration, flexibility in configuration, and out-of-the-box production readiness make it a go-to solution for apps requiring multilingual support. Whether you're just starting your translation journey or looking to streamline your existing setup, Next-i18next makes internationalizing your Next.js app as simple as possible.