useMutation Tutorial 🎯Welcome to our comprehensive guide on React Query's useMutation! This tutorial is designed to cater to both beginners and intermediate learners, so let's dive in!
useMutation is a React Query hook that allows you to perform mutations (changes) on your data. It's a powerful tool for managing side-effects in your React applications.
useMutation?useMutation handles the logic for sending requests, handling errors, and updating the state for you.useQuery for a cohesive data management solution.Before we dive into the useMutation hook, ensure you have React and React Query installed in your project. If not, you can install them using npm or yarn:
npm install react react-queryor
yarn add react react-queryuseMutationimport { useMutation } from 'react-query';Let's create a simple mutation to create a new post in a mock API.
const createPostMutation = async (title) => {
const response = await fetch('https://api.example.com/posts', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
},
body: JSON.stringify({ title }),
});
const data = await response.json();
return data;
};
// Use the mutation in a functional component
const PostForm = () => {
const [createPost, { isLoading, error }] = useMutation(createPostMutation);
const handleSubmit = (e) => {
e.preventDefault();
const title = e.target.title.value;
createPost(title);
};
return (
<form onSubmit={handleSubmit}>
<input type="text" name="title" placeholder="Enter post title" />
<button type="submit" disabled={isLoading}>
{isLoading ? 'Saving...' : 'Save Post'}
</button>
{error && <div>Error: {error.message}</div>}
</form>
);
};In the example above, useMutation takes a function (createPostMutation) as an argument and returns an array with two elements:
createPost function that you call to execute the mutation.isLoading) and any errors that occurred.What does `useMutation` return in the example above?
useMutation offers several options for configuring your mutations. Let's explore some of them:
You can pass an options object to customize the behavior of your mutation.
const [createPost, { isLoading, error }] = useMutation(createPostMutation, {
onSuccess: (data) => console.log(`Post created: ${data.id}`),
onError: (error) => console.error(`Error creating post: ${error.message}`),
});Here, we've added an onSuccess and onError callback for logging success and error messages, respectively.
React Query's optimistic UI allows you to update the UI before the mutation is confirmed.
const [createPost, { isLoading, error }] = useMutation(createPostMutation, {
onMutate: (title) => {
const prevPosts = queryClient.getQueryData('posts');
queryClient.setQueryData('posts', (oldPosts) => [
...oldPosts,
{ id: crypto.randomUUID(), title },
]);
},
onError: (error, variables, context) => {
queryClient.setQueryData('posts', (oldPosts) => oldPosts.filter((post) => post.id !== context.mutationId));
},
});In this example, we've added an onMutate callback that optimistically adds the new post to the list before the mutation is executed, and an onError callback that removes the post from the list if the mutation fails.
With this tutorial, you've learned the basics of using the useMutation hook in your React applications. Happy coding! 🚀
Remember to check back on CodeYourCraft for more in-depth tutorials and resources to help you master React Query! 📝
What is the primary purpose of the `useMutation` hook in React Query?