Question 174518 in Javascript Question posted in
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Javascript – React Context not updating Header buttons after user authentication, how can I fix this?

I’m currently developing a web application using React on the front-end and Express.js for my back-end, where I’m implementing user authentication. I’m able to successfully register and authenticate users, and I generate a JWT which is then stored in a cookie. The problem I’m facing is with updating my header buttons based on the authentication state of the user.

In my React application, I have an AuthContext which holds the user’s authentication status:

const AuthContext = createContext();

const AuthProvider = ({ children }) => {
  const [user, setUser] = useState(null);
  const [isLoading, setLoading] = useState(true);
  const [error, setError] = useState(null);
  const [isLoggedIn, setIsLoggedIn] = useState(false);
  
  // ...rest of the code

  return (
    <AuthContext.Provider value={{ user, isLoading, error, login, logout }}>
      {children}
    </AuthContext.Provider>
  );
};

export { AuthContext, AuthProvider };

When a user logs in, I update isLoggedIn state to true:

const login = async (username, password) => {
  const data = await handleRequest(
    axios.post('/login', { username, password }),
  );
  // ...rest of the code
  setIsLoggedIn(true); 
};

In my Header component, I use this isLoggedIn state to determine which buttons to show:

const { user, isLoading, error, login, logout } = useContext(AuthContext);
//... rest of the code
{!user && <Link to="/login">Login</Link>}
{user && <button onClick={logout}>Logout</button>}

The issue is that after the user logs in, the Header buttons do not update. The user has to manually refresh the page for the buttons to update based on the new authentication state.

Does anyone have any suggestions as to why this might be happening and how I can get my Header to automatically update after a user logs in?

Thanks !

Tags:

2

Answers


  1. 0

    The problem you’re facing is that the Header component does not automatically update after a user logs in. This happens because the AuthContext’s state change does not trigger a re-render of the Header component. To address this issue, you can modify your code to ensure that the Header component receives updates when the authentication state changes.

    One approach is to use the useEffect hook in your Header component to subscribe to changes in the authentication state. Here’s an updated version of your Header component that incorporates this approach:

    
const Header = () => {
  const { user, isLoading, error, login, logout } = useContext(AuthContext);
  const [isLoggedIn, setIsLoggedIn] = useState(false);

  useEffect(() => {
    setIsLoggedIn(!!user); // Update the local state when the user value changes
  }, [user]);

  return (
    <header>
      {!isLoggedIn && <Link to="/login">Login</Link>}
      {isLoggedIn && <button onClick={logout}>Logout</button>}
    </header>
  );
}; 
export default Header;
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  2. 0

    One solution could be to update the user state in the AuthContext when the isLoggedIn state is updated in the login function. This will trigger a re-render of the Header component and update the buttons accordingly.

    You can modify the login function as follows:

        const login = async (username, password) => { 
         const data = await handleRequest( 
               axios.post('/login', { username, password }), ); // ...rest of the code 
        setIsLoggedIn(true); 
        setUser(data.user); // assuming the user data is returned in the response 
   };

    Then, in the AuthContext, you can pass the updated user state to the value prop:

    return ( 
     <AuthContext.Provider 
          value={{ user, isLoading, error, login, logout, setUser }}
     > {children} </AuthContext.Provider> 
);

    Finally, in the Header component, you can update the user state using the setUser function:

    const { user, isLoading, error, login, logout, setUser } = useContext(AuthContext); //... rest of the code 
useEffect(() => { 
    const fetchData = async () => { 
         const data = await handleRequest(axios.get('/user')); 
         setUser(data.user); // assuming the user data is returned in the response 
    }; 
    fetchData(); 
}, [isLoggedIn]);

    This will fetch the updated user data from the server and update the user state, triggering a re-render of the Header component and updating the buttons.

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