React Query : A Deep Dive into Advanced Features

Deep Dive into React Query

React Query is a robust library for fetching, caching, synchronizing, and updating server state data in your React applications. It provides a set of hooks that enable you to fetch data from your server, cache the data, and automatically update the data in the background. This blog post will explore the advanced features, compare it to other data-fetching libraries, and illustrate its use with code examples.

What is React Query For?

React Query is a powerful tool for managing asynchronous state in your React applications. It abstracts the complexities of data fetching, caching, and state management, allowing you to focus on building your application. React Query provides out-of-the-box features such as automatic garbage collection, window focus refetching, and more. This is why React Query is good for managing server state in your React applications.

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1import { useQuery } from "react-query";
2function Example() {
3  const { isLoading, error, data } = useQuery("repoData", () =>
4    fetch("https://api.github.com/repos/tannerlinsley/react-query").then(
5      (res) => res.json(),
6    ),
7  );
8  if (isLoading) return "Loading...";
9  if (error) return "An error has occurred: " + error.message;
10  return (
11    <div>
12      <h1>{data.name}</h1>
13      <p>{data.description}</p>
14      <strong>👀 {data.subscribers_count}</strong>
15      <strong>✨ {data.stargazers_count}</strong>
16      <strong>🍴 {data.forks_count}</strong>
17    </div>
18  );
19}

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React Query vs Redux

Redux is a state management library that is often used in combination with React. However, Redux is not designed to handle server state, which is where it shines. It is a more suitable choice for fetching, caching, and managing asynchronous data. Unlike Redux, It eliminates the need for reducers, action types, and action creators. Instead, it uses hooks and relies on the server as the single source of truth.

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1// With Redux
2
3const fetchUser = (id) => (dispatch) => {
4  dispatch({ type: "FETCH_USER_REQUEST" });
5
6  return fetch(`/api/user/${id}`)
7    .then((response) => response.json())
8
9    .then((data) => dispatch({ type: "FETCH_USER_SUCCESS", payload: data }))
10
11    .catch((error) => dispatch({ type: "FETCH_USER_FAILURE", payload: error }));
12};
13
14// With React Query
15
16const fetchUser = async (id) => {
17  const response = await fetch(`/api/user/${id}`);
18
19  return response.json();
20};
21
22const { data: user, isLoading, isError } = useQuery(["user", id], fetchUser);

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Why Not Use React Query?

Despite its many benefits, React Query may not be suitable for all use cases. React Query is a powerful tool for server state management, but it might be overkill for simple applications that don't require advanced features like caching, automatic refetching, or background updates. For such applications, a simpler data fetching library or even the native fetch API might be sufficient.

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React Query vs Axios

Axios is a popular library for making HTTP requests. It's lightweight, supports promises, and works in both the browser and Node.js. However, Axios is just a HTTP client and does not provide features like caching, automatic refetching, or background updates. React Query, on the other hand, provides all these features out-of-the-box and can be used with any data fetching library, including Axios.

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1// With Axios
2
3const fetchUser = async (id) => {
4  const response = await axios.get(`/api/user/${id}`);
5
6  return response.data;
7};
8
9// With React Query
10
11const fetchUser = async (id) => {
12  const response = await axios.get(`/api/user/${id}`);
13
14  return response.data;
15};
16
17const { data: user, isLoading, isError } = useQuery(["user", id], fetchUser);

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React Axios vs React Query

React Axios is a wrapper around Axios that provides a set of React hooks for using Axios in a React application. While React Axios provides a more React-friendly API than plain Axios, it still lacks many of the features that React Query provides. React Query not only provides a set of hooks for fetching data, but it also provides advanced features like caching, background updates, and automatic refetching.

The Use of React Query in Hook

React Query provides a set of hooks that you can use to fetch, cache, and update data in your React applications. The primary hook is useQuery, which you can use to fetch data from your server, cache it, and automatically update it in the background. Here's an example of how you might use the useQuery hook to fetch data from a server:

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1const { data, error, isLoading } = useQuery("todos", fetchTodos);
2
3if (isLoading) {
4  return <div>Loading...</div>;
5}
6
7if (error) {
8  return <div>An error has occurred: {error.message}</div>;
9}
10
11return (
12  <ul>
13    {data.map((todo) => (
14      <li key={todo.id}>{todo.title}</li>
15    ))}
16  </ul>
17);

In this example, useQuery is used to fetch a list of todos from the server. The useQuery hook returns an object containing the data, any error that occurred, and a boolean indicating whether the data is still loading.

React Query also provides the useMutation hook, which you can use to perform mutations (create, update, delete) on your server data. Here's an example of how to use the useMutation hook:

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1const mutation = useMutation((newTodo) => axios.post("/todos", newTodo), {
2  onSuccess: () => {
3    // Invalidate and refetch
4
5    queryClient.invalidateQueries("todos");
6  },
7});
8
9// In your event handler
10
11const handleAddTodo = () => {
12  mutation.mutate({ id: Date.now(), title: "New Todo" });
13};

In this example, the useMutation hook is used to create a new todo. When the mutation is successful, the onSuccess callback invalidates and refetches the 'todos' query, ensuring the data is up-to-date.

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Fetching Data with React Query

Fetching data with React Query is straightforward thanks to the useQuery hook. You simply pass your fetch function to useQuery, and it takes care of fetching the data, caching it, and updating it in the background. Here's an example:

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1const fetchUser = async () => {
2  const res = await fetch("/api/user");
3
4  if (!res.ok) {
5    throw new Error("Network response was not ok");
6  }
7
8  return res.json();
9};
10
11const UserInfo = () => {
12  const { data, status } = useQuery("user", fetchUser);
13
14  if (status === "loading") {
15    return <div>Loading...</div>;
16  }
17
18  if (status === "error") {
19    return <div>Error fetching data</div>;
20  }
21
22  return (
23    <div>
24      <h3>{data.name}</h3>
25
26      <p>{data.email}</p>
27    </div>
28  );
29};

In this example, useQuery fetches the user data when the UserInfo component mounts. The data is then cached, and any subsequent re-renders of the UserInfo component will use the cached data instead of refetching it from the server.

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Advanced Features of React Query

React Query provides several advanced features out of the box that can significantly enhance your data fetching capabilities:

Query Caching

React Query automatically caches your queries and the data they return. This can drastically improve the performance of your application by minimizing the number of network requests. Query caching in React Query is flexible and configurable, and React Query ensures that your cache is always up-to-date with the latest data from your server.

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1const { data } = useQuery('todos', fetchTodos);

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Automatic Refetching

React Query automatically refetches your queries under certain conditions to ensure that your data is always up-to-date. For example, React Query will refetch your queries when your application regains focus or when you reconnect to the internet. This feature is especially useful for applications that need to work offline and then sync with the server when back online.

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Pagination and Infinite Queries

React Query provides out-of-the-box support for pagination and infinite queries. This allows you to fetch data in chunks, improving the performance of your application and providing a better user experience.

Here's an example of how you can implement infinite scrolling using the useInfiniteQuery hook:

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1const fetchPosts = async ({ pageParam = 1 }) => {
2  const res = await fetch(`/api/posts?page=${pageParam}`);
3  return res.json();
4};
5const Posts = () => {
6  const { data, fetchNextPage, hasNextPage, isFetchingNextPage } =
7    useInfiniteQuery("posts", fetchPosts, {
8      getNextPageParam: (lastPage, pages) => lastPage.nextPage,
9    });
10  return (
11    <>
12      {data.pages.map((group, i) => (
13        <React.Fragment key={i}>
14          {group.posts.map((post) => (
15            <p key={post.id}>{post.title}</p>
16          ))}
17        </React.Fragment>
18      ))}
19      <div>
20        <button
21          onClick={() => fetchNextPage()}
22          disabled={!hasNextPage || isFetchingNextPage}
23        >
24          {isFetchingNextPage
25            ? "Loading more..."
26            : hasNextPage
27            ? "Load More"
28            : "Nothing more to load"}
29        </button>
30      </div>
31    </>
32  );
33};

In this example, useInfiniteQuery is used to fetch posts from the server in chunks. The fetchNextPage function is used to fetch the next page of posts, and the hasNextPage boolean is used to determine whether there are more pages to load.

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Devtools

React Query provides a set of Devtools that can help you debug your queries and mutations. The Devtools provide a real-time view of your queries, their status, and their data. They also allow you to manually refetch queries, inspect the query cache, and more.

To enable the Devtools, simply import the ReactQueryDevtools component from 'react-query/devtools' and include it in your component tree:

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1 import { ReactQueryDevtools } from 'react-query/devtools'
2    function App() {
3       return (
4    <div>
5    {/* Your application */}
6    <ReactQueryDevtools initialIsOpen={false}>
7    </div>
8    )}

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WiseGPT: Streamlining React Query Code Generation for All Versions

WiseGPT is an innovative IDE plug-in for Visual Studio Code that empowers developers to write efficient data fetching code using React Query effortlessly. By importing a Postman collection, WiseGPT becomes a prompt-less generative AI that mirrors your coding style and structure while automatically generating performance-driven code. Let's explore the key features of WiseGPT that support code generation for React Query across all versions:

Seamless React Query Integration

WiseGPT seamlessly integrates with React Query, recognizing its different versions and adapting to the specific API changes. Whether you're using React Query 3.x or the latest v4, WiseGPT provides relevant prompts and code suggestions tailored to the version you're working with.

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Code Generation with WiseGPT

WiseGPT understands the common data-fetching patterns in React applications and automatically generates optimized code for scenarios like fetching single resources, lists of data, and handling pagination. Whether you're using queries or mutations, WiseGPT generates React Query code that adheres to best practices and ensures optimal performance.

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Advanced Query Configuration

React Query offers a wide range of configuration options to fine-tune data fetching behavior. WiseGPT provides prompts and suggestions for these configurations, making it easy to set up features like caching, background data fetching, automatic refetching, and more. No more digging through documentation – WiseGPT has got you covered!

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Custom Hooks for Data Fetching

To promote code reusability and maintainable architecture, WiseGPT generates custom hooks for data fetching with React Query. These hooks encapsulate the data-fetching logic, ensuring consistency across your application and reducing code duplication.

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Handling Authentication and Error Handling

Authentication and error handling are essential aspects of data fetching. WiseGPT generates code that integrates authentication mechanisms seamlessly with React Query. Additionally, it handles error scenarios gracefully, providing suggestions on how to display error messages to users and handle retries with React Query's built-in features.

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Optimized Pagination

Dealing with paginated data can be complex, but WiseGPT simplifies the process by generating code that effectively handles pagination with React Query. Whether you're implementing infinite scrolling or a "load more" button, WiseGPT generates code that ensures smooth data loading and a positive user experience.

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TypeScript Support

For developers using TypeScript, WiseGPT's code generation is type-safe and fully compatible with React Query's TypeScript API. It infers types correctly, reducing the likelihood of runtime errors and enabling a seamless development experience.

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Scalability and Multi-file Code Generation

WiseGPT excels at handling large-scale applications by generating code across multiple files without any output token limit. Even in complex projects.

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Intelligent Commenting and Documentation

Technical debt can arise from lack of clarity in code. WiseGPT addresses this by adding meaningful comments and documentation to the generated code. These comments provide insights into the purpose and functionality of different code sections, enhancing code readability and making it easier for developers to maintain and collaborate on the project.

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Automatic Code Formatting

Consistent code formatting is crucial for project maintainability. WiseGPT automatically formats the generated code to match your coding style, ensuring a cohesive and organized codebase.

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Conclusion

In conclusion, React Query is a powerful tool for fetching, caching, and managing server state in your React applications. It provides a set of hooks that make data fetching a breeze, and it comes with a host of advanced features like automatic refetching, query caching, pagination, infinite queries, and Devtools. If you're building a React application that needs to fetch data from a server, React Query is definitely worth a look.