How to run 2 instances of ReactI18Next on the same app?

The need to run two react-i18next instances within the same application typically arises when managing multiple distinct localization resources or configurations. For instance, one instance might be dedicated to translating the user interface, while another handles translations for specific modules or libraries. Below are the steps to achieve this functionality:

1. Install the necessary libraries

First, ensure your project has the required packages installed:

bash
npm install i18next react-i18next

2. Create two independent i18n instances

You can implement this by defining two separate i18n configurations. Here is an example of how to create these instances:

javascript
import i18n from 'i18next';
import { initReactI18next } from 'react-i18next';

// First i18n instance
const i18nInstance1 = i18n.createInstance();
i18nInstance1
  .use(initReactI18next)
  .init({
    resources: {
      en: { translation: { key: "Hello from Instance 1" } },
      fr: { translation: { key: "Bonjour de l'instance 1" } },
    },
    lng: "en",
    interpolation: { escapeValue: false },
  });

// Second i18n instance
const i18nInstance2 = i18n.createInstance();
i18nInstance2
  .use(initReactI18next)
  .init({
    resources: {
      en: { translation: { key: "Hello from Instance 2" } },
      fr: { translation: { key: "Bonjour de l'instance 2" } },
    },
    lng: "en",
    interpolation: { escapeValue: false },
  });

3. Use the corresponding instances

In your React components, utilize the I18nextProvider to apply these separate instances. For example:

javascript
import React from 'react';
import { I18nextProvider, useTranslation } from 'react-i18next';

function App() {
  return (
    <div>
      <I18nextProvider i18n={i18nInstance1}>
        <MyComponent instance="Instance 1" />
      </I18nextProvider>
      <I18nextProvider i18n={i18nInstance2}>
        <MyComponent instance="Instance 2" />
      </I18nextProvider>
    </div>
  );
}

function MyComponent({ instance }) {
  const { t } = useTranslation();
  return <p>{t('key')} from {instance}</p>;
}

4. Considerations

• Ensure the resources and configurations of each instance do not conflict with one another.
• Using multiple instances may increase application complexity and resource consumption; therefore, carefully evaluate your requirements before implementing this approach.

This method provides a practical solution for running two react-i18next instances within the same application, which is particularly valuable when managing large-scale applications or highly modularized translation resources.