Efficiently Manage Authentication in React Apps with React Query

Managing authentication with React Query involves setting up queries to handle user sign-in and sign-out, as well as using mutations to send credentials to a server. This post goes into more detail on how that all works.

How to handle user authentication with React Query?

To manage user authentication, you can use React Query's useQuery for fetching the current authentication state (e.g., checking if the user is logged in) and useMutation for performing sign-in and sign-out actions. This approach helps in managing the loading, error, and data states efficiently.

Setting up authentication state query

First, you need to define a function that checks the user's authentication status. This function can call an API endpoint that verifies the user's session or token validity.

const fetchAuthStatus = async () => {
  const response = await fetch('/api/auth/status');
  if (!response.ok) {
    throw new Error('Network response was not ok');
  }
  return response.json();
};

Then, use the useQuery hook to fetch the authentication status:

import { useQuery } from 'react-query';

const { data: user, isLoading, isError } = useQuery('authStatus', fetchAuthStatus, {
  staleTime: Infinity, // Adjust based on your needs
  cacheTime: 0, // Consider security implications
});

Implementing sign-in and sign-out mutations

For mutating the authentication state, such as signing in or out, use the useMutation hook. Define functions to handle these actions, typically making POST requests to your authentication API.

const signIn = async ({ email, password }) => {
  const response = await fetch('/api/auth/signin', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({ email, password }),
  });
  if (!response.ok) {
    throw new Error('Sign in failed');
  }
  return response.json();
};

const signOut = async () => {
  const response = await fetch('/api/auth/signout', { method: 'POST' });
  if (!response.ok) {
    throw new Error('Sign out failed');
  }
  return true;
};

Use these functions with useMutation to perform sign-in and sign-out actions:

import { useMutation } from 'react-query';

const { mutate: signInUser } = useMutation(signIn, {
  onSuccess: () => {
    // Handle successful sign in, e.g., refetch the auth status
    queryClient.invalidateQueries('authStatus');
  },
});

const { mutate: signOutUser } = useMutation(signOut, {
  onSuccess: () => {
    // Handle successful sign out, e.g., clear the user data or redirect
    queryClient.removeQueries('authStatus');
  },
});

"What are the benefits of using React Query for authentication?"

Using React Query for authentication in React applications simplifies state management by automatically handling loading states, caching, and data synchronization. It reduces the boilerplate code typically associated with managing asynchronous data and state, making your application more robust and maintainable.

Remember to handle security considerations, such as securely storing authentication tokens and ensuring sensitive user information is protected throughout your application. React Query's flexibility and utility functions can help manage these aspects efficiently, but always review best practices for web security in the context of your specific application needs.