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React Query - A Complete Guide

React Query - A Complete Guide

Master React Query with this comprehensive guide. Learn data fetching, mutations, pagination, and advanced techniques to optimize your React applications.

Yogini Bende

Yogini Bende

Oct 13, 2024 4 min read

React Query has emerged as a powerful library that simplifies data fetching and state management tasks, offering a robust solution for handling server state in React applications. Developed by Tanstack, React Query provides easy and robust way to fetch and manage remote data.

In this article, we will dive deep into React Query, exploring its features, benefits, and advanced techniques. By the end of this guide, you'll have a thorough understanding of React Query and how to leverage its capabilities in your React projects.

We'll cover everything from basic data fetching to advanced querying techniques, equipping you with the knowledge to optimize your applications and enhance user experience.

Let's dive in!

What is React Query?

React Query is a powerful data-fetching and state management library developed by TanStack for React applications. It provides a robust solution for handling server state, offering automatic caching, background synchronization, and optimized data fetching out of the box.

Installation and Setup

# Using npm
npm install @tanstack/react-query

# Using yarn
yarn add @tanstack/react-query

To get started, wrap your application with the QueryClientProvider:

import { QueryClient, QueryClientProvider } from '@tanstack/react-query'

const queryClient = new QueryClient()

function App() {
  return (
    <QueryClientProvider client={queryClient}>
      <YourApp />
    </QueryClientProvider>
  )
}

Why Choose React Query?

React Query solves several critical challenges in modern web development:

  1. Simplified State Management

    • Eliminates the need for complex global state management for server data

    • Reduces boilerplate code compared to traditional Redux/Context solutions

    • Provides an intuitive API for data fetching and updates

  2. Automatic Performance Optimization

    • Implements smart caching strategies out of the box

    • Reduces unnecessary network requests

    • Handles background data synchronization automatically

  3. Enhanced Developer Experience

    • Offers clear separation between server and client state

    • Provides built-in loading and error states

    • Includes powerful dev tools for debugging

  4. Real-time Data Management

    • Maintains UI synchronization with server data

    • Supports optimistic updates

    • Handles concurrent requests efficiently

Core Concepts and Basic Usage

Querying Data with useQuery

The useQuery hook is the foundation of data fetching in React Query:

import { useQuery } from '@tanstack/react-query'
import axios from 'axios'

function Posts() {
  const { data, isLoading, error } = useQuery({
    queryKey: ['posts'],
    queryFn: async () => {
      const { data } = await axios.get('https://api.example.com/posts')
      return data
    }
  })

  if (isLoading) return <div>Loading posts...</div>
  if (error) return <div>Error: {error.message}</div>

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

Mutations with useMutation

Handle data updates using the useMutation hook:

import { useMutation, useQueryClient } from '@tanstack/react-query'

function CreatePost() {
  const queryClient = useQueryClient()
  
  const mutation = useMutation({
    mutationFn: (newPost) => {
      return axios.post('https://api.example.com/posts', newPost)
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['posts'] })
    }
  })

  return (
    <form onSubmit={(e) => {
      e.preventDefault()
      mutation.mutate({ title: e.target.title.value })
    }}>
      <input name="title" />
      <button type="submit">Create Post</button>
    </form>
  )
}

Advanced Features and Integration

Integration with Next.js

React Query works seamlessly with Next.js. Here's how to set it up:

// pages/_app.js
import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
import { ReactQueryDevtools } from '@tanstack/react-query-devtools'

const queryClient = new QueryClient()

function MyApp({ Component, pageProps }) {
  return (
    <QueryClientProvider client={queryClient}>
      <Component {...pageProps} />
      <ReactQueryDevtools initialIsOpen={false} />
    </QueryClientProvider>
  )
}

Implementing Pagination

React Query simplifies pagination implementation:

function PaginatedPosts() {
  const [page, setPage] = useState(1)
  
  const { data, isPreviousData } = useQuery({
    queryKey: ['posts', page],
    queryFn: () => fetchPosts(page),
    keepPreviousData: true
  })

  return (
    <div>
      {data.posts.map(post => (
        <div key={post.id}>{post.title}</div>
      ))}
      <button
        onClick={() => setPage(old => Math.max(old - 1, 1))}
        disabled={page === 1}
      >
        Previous
      </button>
      <button
        onClick={() => setPage(old => old + 1)}
        disabled={isPreviousData || !data?.hasMore}
      >
        Next
      </button>
    </div>
  )
}

Infinite Scrolling

Implement infinite scrolling using useInfiniteQuery:

function InfinitePostList() {
  const {
    data,
    fetchNextPage,
    hasNextPage,
    isFetchingNextPage
  } = useInfiniteQuery({
    queryKey: ['posts'],
    queryFn: fetchPostPage,
    getNextPageParam: (lastPage) => lastPage.nextCursor
  })

  return (
    <div>
      {data.pages.map((page, i) => (
        <React.Fragment key={i}>
          {page.posts.map(post => (
            <div key={post.id}>{post.title}</div>
          ))}
        </React.Fragment>
      ))}
      <button
        onClick={() => fetchNextPage()}
        disabled={!hasNextPage || isFetchingNextPage}
      >
        {isFetchingNextPage
          ? 'Loading more...'
          : hasNextPage
          ? 'Load more'
          : 'Nothing more to load'}
      </button>
    </div>
  )
}

Best Practices and Optimization Tips

  • Query Keys

    • Use array syntax for dynamic query keys

    • Include all dependencies in the query key

    • Keep keys consistent across your application

  • Caching Strategies

    • Configure staleTime based on data freshness requirements

    • Use cacheTime to control cache persistence

    • Implement optimistic updates for better UX

  • Error Handling

    • Set up global error handlers

    • Implement retry logic for failed queries

    • Provide meaningful error messages to users

Conclusion

React Query transforms how we handle server state in React applications, providing a powerful yet intuitive API for data management. Whether you're building a simple CRUD application or a complex data-intensive platform, React Query's features and optimizations make it an excellent choice for modern web development.

For more detailed information and advanced use cases, refer to the official React Query documentation.

Remember to:

  • Start with basic queries and gradually incorporate advanced features

  • Utilize the React Query DevTools during development

  • Keep your query keys consistent and well-organized

  • Configure caching strategies based on your specific use case

And if you are looking for a Frontend Developer Job, you will find many good opportunities on Peerlist Jobs. Don't forget to check them out.
Until then, keep building! 👨‍💻

Happy querying!

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