Difference between useTranslation and direct import from i18next

Question

Is there any practical difference between importing the useTranslation hook, then getting the t() function from it:

import { useTranslation } from 'react-i18next';

// Inside a component:
const { t } = useTranslation();

and importing the t() function directly from i18next:

import { t } from 'i18next';

Answer 1

Yes, there is a practical difference between these two approaches:

1. useTranslation() from react-i18next:

import { useTranslation } from 'react-i18next';

const { t } = useTranslation();

• React Context: This hook is designed for React components. It ensures that the t function is bound to the current React context, which means it takes care of context-specific language settings, like the current language or namespace that may change during the lifecycle of your application.
• Automatic updates: If the language is changed using i18next.changeLanguage(), the component will automatically re-render with the new translations.
• Namespaces: If your project uses different namespaces for translation (e.g., 'common', 'footer'), the hook provides flexibility in switching between them at the component level.
• SSR Support: This method is optimal for server-side rendering (SSR) and can ensure that translations are loaded on both server and client-side correctly.

2. Direct import from i18next:

import { t } from 'i18next';

• No React Integration: This approach directly uses the i18next instance. It doesn't have any connection to the React context, so it won't re-render components when the language changes.
• Static translation: The t function is static and won’t trigger re-renders if the language changes. It's useful when you need translations outside of a React component or in non-React code.
• Namespaces and Context: Since it doesn't integrate with React’s context, you may need to manually handle things like setting or switching namespaces and ensuring translations are updated.

In summary:

• Use useTranslation() in React components for dynamic translations that update when language changes.
• Use the direct t import when you're outside of React components or when you don't need the component to re-render on language change.