What is RTK Query used for?

RTK Query is a tool from the Redux Toolkit suite designed to simplify working with asynchronous API requests and managing server state in React applications. It automates the process of fetching, caching, updating, and synchronizing data with the server, minimizing boilerplate code.

Main advantages of RTK Query:

• Automatic caching and data updating.
• Integration with Redux without the need to write reducers and actions manually.
• Support for automatic refetching on errors or data updates.
• Convenient hooks for use in React components.

Example usage:

import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react';

const api = createApi({
  reducerPath: 'api',
  baseQuery: fetchBaseQuery({ baseUrl: '/api' }),
  endpoints: (build) => ({
    getPosts: build.query({
      query: () => 'posts',
    }),
  }),
});

export const { useGetPostsQuery } = api;

// In a component
function Posts() {
  const { data, error, isLoading } = useGetPostsQuery();

  if (isLoading) return <div>Loading...</div>;
  if (error) return <div>Loading error</div>;

  return <ul>{data.map(post => <li key={post.id}>{post.title}</li>)}</ul>;
}