TanStack Query, formerly known as React Query, is a powerful library for managing asynchronous data in React applications. It provides hooks like useQuery for fetching data and useMutation for sending data. The library handles caching, background updates, error handling, and loading states automatically, making data fetching much simpler and more robust. To get started, you can install it using npm or yarn.
Before using TanStack Query hooks in your React application, you need to set up the QueryClientProvider. First, create a QueryClient instance, then wrap your application's root component with QueryClientProvider. This provides the QueryClient instance to all components within the component tree, enabling them to use query hooks like useQuery and useMutation.
The useQuery hook is the primary way to fetch data in TanStack Query. It takes a configuration object with a unique query key and an async query function. The hook returns an object containing the fetched data, loading state, error state, and error details. You can use these states to conditionally render loading indicators, error messages, or the actual data in your component.
The useMutation hook is used for operations that modify data on the server, such as POST, PUT, or DELETE requests. It provides a mutate function to trigger the mutation and tracks its loading, error, and success states. You can use the onSuccess callback to invalidate related queries, ensuring your UI stays in sync with the server data after successful mutations.
To summarize what we have learned about TanStack Query: It simplifies data fetching in React applications by providing powerful hooks. Setup requires wrapping your app with QueryClientProvider. The useQuery hook handles data fetching with automatic caching, while useMutation manages data updates. These tools provide built-in loading states and error handling that greatly improve the user experience.