How to complete login authentication in react by using react query mutations?

When using React Query for authentication mutations, the key steps involve setting up the login mutation and processing the response to update the application state or handle errors. The following are the detailed steps to implement this:

1. Installing and Importing React Query

First, ensure React Query is installed in your project.

bash
npm install react-query

In your component or service file, import the necessary React Query features.

javascript
import { useMutation } from 'react-query';

2. Creating the Login Function

Implement a function to handle API requests, taking username and password as parameters and returning a Promise.

javascript
const loginUser = async (username, password) => {
  const response = await fetch('/api/login', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({ username, password }),
  });

  if (!response.ok) {
    throw new Error('Network response was not ok');
  }

  return response.json();
};

3. Using the useMutation Hook

In your component, use the useMutation hook to manage the login process. This hook allows you to send mutations while handling state and errors.

javascript
function Login() {
  const mutation = useMutation(({ username, password }) => loginUser(username, password), {
    onSuccess: (data) => {
      // Handle successful login, e.g., save token, redirect to another page, etc.
      console.log('Login successful:', data);
    },
    onError: (error) => {
      // Handle errors, e.g., display error message
      console.error('Login failed:', error);
    },
  });

  const handleSubmit = (event) => {
    event.preventDefault();
    const username = event.target.elements.username.value;
    const password = event.target.elements.password.value;
    mutation.mutate({ username, password });
  };

  return (
    <form onSubmit={handleSubmit}>
      <input type="text" placeholder="Username" name="username" required />
      <input type="password" placeholder="Password" name="password" required />
      <button type="submit">Login</button>
      {mutation.isLoading && <p>Loading...</p>}
      {mutation.isError && <p>Error: {mutation.error.message}</p>}
      {mutation.isSuccess && <p>Login Successful!</p>}
    </form>
  );
}

4. Error Handling and Loading States

React Query provides state indicators like isLoading, isError, and isSuccess for mutations, which can be used to display UI elements such as loading indicators, error messages, or success states.

Practical Example

Using these techniques, you can implement user login and handle various states during the process, while enhancing user experience by showing loading states during requests and providing clear error feedback. The advantage of React Query is that it manages asynchronous operation states (e.g., loading, errors, and data caching) and enables developers to easily implement complex features like automatic retries and data dependency refreshes through its robust configuration options and hooks.