Overview (v9)

react-i18next depends on i18next to provide the localization features. So there are two main things flowing through your render tree:

1. The i18next instance (short i18n)

2. The translation function (short t)

While we primary rely on react context to pass down i18n and t the components are built to also accept those via props, options or in case of i18n via internal context / reactI18nextModule.

Components

Component	Props	Provides	Consumes
I18nextProvider	i18n, defaultNS	i18n, defaultNs
NamespacesConsumer is a render prop		t, i18n	i18n
withNamespaces hoc		t, i18n	i18n
Trans Component is used to translate JSX nodes where just using t is insufficient			t, i18n

This means your tree will look something like this (assuming you use the options I18nextProvider):

I18nextProvider --> NamespacesConsumer or withNamespaces HOC --> Trans or using t in your component

import { I18nextProvider, NamespacesConsumer, Trans, withNamespaces } from 'react-i18next';
import i18n from `./i18n`; // the initialized i18next instance

export default function App () {
  return (
    <I18nextProvider i18n={i18n}>
      <NamespacesConsumer>
        {
          t => <h1>{t('key')}</h1>
        }
      </NamespacesConsumer>
      <MyComponentWithHoc />
    </I18nextProvider>
  )
}

function MyComponent({ t }) {
  return (
    <Trans i18nKey="userMessagesUnread" count={count}>
      Hello <strong title={t('nameTitle')}>{{name}}</strong>, you have {{count}} unread message. <Link to="/msgs">Go to messages</Link>.
    </Trans>
  )
}

const MyComponentWithHoc = withNamespaces()(MyComponent);

Getting the t function

To get the t function (providing the translation functionality) down to your component you have two options:

1. Using the withNamespaces hoc
2. Using the NamespacesConsumer render prop

Getting the i18n function into the flow

You have the following options to pass the i18next instance to the hoc, render prop and Trans component:

Use the provider

import React from 'react';
import ReactDOM from 'react-dom';
import { I18nextProvider } from 'react-i18next';

import App from './App'; // your entry page
import i18n from './i18n'; // initialized i18next instance

ReactDOM.render(
  <I18nextProvider i18n={ i18n }>
    <App />
  </I18nextProvider>,
  document.getElementById('app')
);

Use the reactI18nextModule

import i18n from 'i18next';
import { reactI18nextModule } from 'react-i18next';


i18n
  .use(reactI18nextModule) // if not using I18nextProvider
  .init({ /* options */ });

export default i18n;