Frontend applications interact with the backend to fetch and persist data, and the most common way they do this in modern web development is through Rest APIs.

When creating a large scale frontend application, efficient handling of network requests, caching the data to avoid unnecessary request calls, handling pagination, lazy loading, infinite scrolling, background data synchronization, etc. are important factors that one should consider to create a performant app.

It is not easy to handle all this through manual code, as it increases the chances of errors or bugs and could also lead to having lots of redundant code throughout the codebase that could be challenging to maintain.

React-query is a powerful library that is designed for query management in the React and Nextjs frameworks.

Developed by TanStack, it also supports other popular front-end frameworks.

What is React-Query?

React-Query is a library that helps with query management. A powerful data synchronization library that comes with a set of hooks could be used for fetching, caching, and updating data in the React application. React Query caches data using a stale-while-revalidate technique, which updates the cache in the background as soon as new data becomes available, serving stale data immediately.

It is not a state-management library but can be used along with popular ones like Zustand and Redux.

It comes with a powerful API and crisp and clear documentation that makes it easy to adopt.

Employing React-Query with state management libraries is like running the frontend framework on a steroid, if used efficiently for applications that rely on heavy I/O operations.

Key features

• Declarative Data Fetching: React Query encourages the use of declarative methods for retrieving data. Use hooks like useQuery and useMutation to define queries and mutations. As a result, the code becomes more structured and tidy.
• Automatic Caching: The query results are stored in an internal cache of React Query. When changes happen, it automatically updates the data to keep your user interface consistent.
• Background Data Sync: Without requiring human input, it can automatically retrieve data in the background to maintain its freshness.
• Pagination and Infinite Scrolling: React Query comes with the tools to make managing these features easy.
• Optimistic Updates: Adding optimistic updates will make your app feel more responsive and easy to implement

How does React-Query works?

The results of data fetching with React Query are kept in a local cache. This implies that React Query will provide the cached results rather than requesting the same data from the API each time. You will always receive the most recent data because the cache is automatically invalidated when the data changes.

Data flow using React-query in React