What is Redux Toolkit Query (RTK Query) & How to Use it?
Published: 2023-11-05 03:59:38

Redux Toolkit Query is a powerful library and set of tools for managing data fetching and caching in a Redux-based application. It simplifies the process of making API requests, handling responses, and caching data, all while integrating seamlessly with Redux, allowing you to manage your application's state effectively. It is commonly used with React applications, but it can be used with other JavaScript frameworks as well.

Redux Toolkit Query provides a standard and efficient way to manage the data retrieval process, and it includes features like caching, automatic invalidation, and revalidation of data, ensuring that your application always has access to the latest data from your API.

Here's how to use Redux Toolkit Query:

1. **Installation**:
   You need to install the necessary packages to get started. You will need `@reduxjs/toolkit`, `@reduxjs/toolkit/query`, and `axios` (or another HTTP client for making API requests).

   ```bash
   npm install @reduxjs/toolkit react-redux @reduxjs/toolkit/query axios
   ```

2. **Setup the API Slice**:
   Start by creating an API slice, which defines your endpoints and how to fetch data from them. This is typically done using the `createApi` function from Redux Toolkit Query. Here's an example of how you can set up an API slice:

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

   const api = createApi({
     baseQuery: fetchBaseQuery({ baseUrl: '/api' }), // Set your API base URL here
     endpoints: (builder) => ({
       // Define your API endpoints here
       getPosts: builder.query('/posts'),
       createPost: builder.mutation({
         query: (newPost) => ({
           url: '/posts',
           method: 'POST',
           body: newPost,
         }),
       }),
     }),
   });

   export const { useGetPostsQuery, useCreatePostMutation } = api;
   ```

3. **Store Configuration**:
   Set up your Redux store to include the API slice. This is done by adding the `api.reducer` and `api.middleware` to your store configuration.

   ```javascript
   import { configureStore } from '@reduxjs/toolkit';
   import { api } from './api'; // Your API slice

   const store = configureStore({
     reducer: {
       [api.reducerPath]: api.reducer,
     },
     middleware: (getDefaultMiddleware) =>
       getDefaultMiddleware().concat(api.middleware),
   });

   export default store;
   ```

4. **Using API Endpoints**:
   In your React components, you can use the generated hooks from Redux Toolkit Query to fetch and mutate data. For example, to fetch a list of posts and create a new post, you can do the following:

   ```javascript
   import React from 'react';
   import { useGetPostsQuery, useCreatePostMutation } from './api'; // Import your API slice

   function MyComponent() {
     const { data, error, isLoading } = useGetPostsQuery(); // Fetch data

     const [createPost] = useCreatePostMutation(); // Mutate data

     const handleCreatePost = async (newPost) => {
       const response = await createPost(newPost);
       if (createPost.error) {
         // Handle error
       }
     }

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

     if (error) {
       return <div>Error: {error.message}</div>;
     }

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

   export default MyComponent;
   ```

5. **Caching and Automatic Data Management**:
   Redux Toolkit Query automatically caches data, and it provides automatic data invalidation and revalidation based on specified conditions, such as when you mutate data. This simplifies data management in your application.

By following these steps, you can effectively use Redux Toolkit Query to manage data fetching and state in your application. It abstracts many of the complexities of data management, making your code more maintainable and efficient.