Internationalization with Intlayer and i18next

i18next is an open-source internationalization (i18n) framework designed for JavaScript applications. It is widely used for managing translations, localization, and language switching in software projects. However, it has some limitations that can complicate scalability and development.

Intlayer is another internationalization framework that addresses these limitations, offering a more flexible approach to content declaration and management. Let's explore some key differences between i18next and Intlayer, and how to configure both for optimal internationalization.

Intlayer vs. i18next: Key Differences

1. Content Declaration

With i18next, translation dictionaries must be declared in a specific folder, which can complicate application scalability. In contrast, Intlayer allows content to be declared within the same directory as your component. This has several advantages:

Simplified Content Editing: Users don't have to search for the correct dictionary to edit, reducing the chance of errors.
Automatic Adaptation: If a component changes location or is removed, Intlayer detects and adapts automatically.

2. Configuration Complexity

Configuring i18next can be complex, especially when integrating with server-side components or configuring middleware for frameworks like Next.js. Intlayer simplifies this process, offering more straightforward configuration.

3. Consistency of Translation Dictionaries

Ensuring that translation dictionaries are consistent across different languages can be challenging with i18next. This inconsistency can lead to application crashes if not handled properly. Intlayer addresses this by enforcing constraints on translated content, ensuring no translation is missed and that the translated content is accurate.

4. TypeScript Integration

Intlayer offers better integration with TypeScript, allowing for auto-suggestions of content in your code, thereby enhancing development efficiency.

Intlayer facilitates the sharing of content declaration files across multiple applications and shared libraries. This feature makes it easier to maintain consistent translations across a larger codebase.

How to Generate i18next Dictionaries with Intlayer

Configuring Intlayer to Export i18next Dictionaries

Important Notes The exportation of i18next dictionaries is currently in beta and does not ensure a 1: 1 compatibility with other frameworks. It is recommended to stick to a configuration based on Intlayer to minimize issues.

To export i18next dictionaries, you need to configure Intlayer appropriately. Below is an example of how to set up Intlayer to export both Intlayer and i18next dictionaries.

// intlayer.config.ts

import { Locales, type IntlayerConfig } from "intlayer";

const config: IntlayerConfig = {
  content: {
    // Indicate that Intlayer will export both Intlayer and i18next dictionaries
    dictionaryOutput: ["intlayer", "i18next"],
    // Relative path from the project root to the directory where i18n dictionaries will be exported
    i18nDictionariesDir: "./i18n/dictionaries",
  },
};

export default config;

By including 'i18next' in the configuration, Intlayer generates dedicated i18next dictionaries in addition to the Intlayer dictionaries. Note that removing 'intlayer' from the configuration may break compatibility with React-Intlayer or Next-Intlayer.

Importing Dictionaries into Your i18next Configuration

To import the generated dictionaries into your i18next configuration, you can use 'i18next-resources-to-backend'. Here is an example of how to import your i18next dictionaries:

// i18n/client.ts

import i18next from "i18next";
import resourcesToBackend from "i18next-resources-to-backend";

i18next
  // Your i18next configuration
  .use(
    resourcesToBackend(
      (language: string, namespace: string) =>
        import(`../i18n-dictionaries/${language}/${namespace}.json`)
    )
  );