I18next -react - how to have 2 instances of i18next in the same app

Creating two i18next instances in a React application is not a typical approach because i18next is designed to be sufficiently flexible, allowing it to handle multiple language environments and translation files through namespaces and different backend loading paths. However, if you do need to instantiate i18next twice within the same application, the following is a basic guide.

First, install the react-i18next library (assuming you have already installed i18next):

bash
npm install react-i18next i18next

Then, you can create two different i18next instances. For example:

javascript
// i18nInstance1.js
import i18n from 'i18next';
import { initReactI18next } from 'react-i18next';

const i18nInstance1 = i18n.createInstance();
i18nInstance1
  .use(initReactI18next) // passes the i18n instance to react-i18next.
  .init({
    // i18n options...
  });

export default i18nInstance1;

javascript
// i18nInstance2.js
import i18n from 'i18next';
import { initReactI18next } from 'react-i18next';

const i18nInstance2 = i18n.createInstance();
i18nInstance2
  .use(initReactI18next) // passes the i18n instance to react-i18next.
  .init({
    // i18n options...
  });

export default i18nInstance2;

Note that each instance should call its own init method and configure its respective translation resources and language environment settings.

Next, in your components, you can use the I18nextProvider component to pass different i18next instances to your React component tree. For example:

javascript
import React from 'react';
import { I18nextProvider } from 'react-i18next';
import i18nInstance1 from './i18nInstance1';
import i18nInstance2 from './i18nInstance2';
import App from './App';

const RootComponent = () => (
  <I18nextProvider i18n={i18nInstance1}>
    {/* Your application that uses i18nInstance1 */}
    <App />
  </I18nextProvider>
);

const AnotherComponentUsingDifferentI18nInstance = () => (
  <I18nextProvider i18n={i18nInstance2}>
    {/* Another part of your application that uses i18nInstance2 */}
    <AnotherApp />
  </I18nextProvider>
);

export { RootComponent, AnotherComponentUsingDifferentI18nInstance };

This way, you can use the first i18next instance in RootComponent and the second instance in AnotherComponentUsingDifferentI18nInstance.

Remember that using two different i18next instances may lead to confusion and management issues, especially when they need to share common translation resources or communicate with each other. Before implementing this architecture, ensure your requirements cannot be resolved through simpler methods, such as using different namespaces, translation files, or other advanced features of i18next.