How to redirect after a user signs in with Firebase authentication?

Question

How can I redirect to a different webpage after the user has signed in?

Currently when a user logs in, data gets retrieved however, it doesn't redirect the user to a different website.

I know I should use 'getRedirectResult', but can someone show me how to use it and how it redirect the user to a different webpage, maintaining the retrieved user data.

My javascript work:

function toggleSignIn() {
  if (!firebase.auth().currentUser) {
    // [START createprovider]
    var provider = new firebase.auth.GoogleAuthProvider();
    // [END createprovider]
    // [START addscopes]
    provider.addScope('https://www.googleapis.com/auth/plus.login');
    // [END addscopes]
    // [START signin]
    firebase.auth().signInWithPopup(provider).then(function(result) {
      // This gives you a Google Access Token. You can use it to access the Google API.
      var token = result.credential.accessToken;
      // The signed-in user info.
      var user = result.user;
      // [START_EXCLUDE]
      document.getElementById('quickstart-oauthtoken').textContent = token;
      // [END_EXCLUDE]
    }).catch(function(error) {
      // Handle Errors here.
      var errorCode = error.code;
      var errorMessage = error.message;
      // The email of the user's account used.
      var email = error.email;
      // The firebase.auth.AuthCredential type that was used.
      var credential = error.credential; 
      // [START_EXCLUDE]
      if (errorCode === 'auth/account-exists-with-different-credential') {
        alert("You have already signed up with a different auth provider for that email.");
        // If you are using multiple auth providers on your app you should handle linking
        // the user's accounts here.
      }
  else if (errorCode === 'auth/auth-domain-config-required') {
    alert("An auth domain configuration is required"); 
      }
      else if (errorCode === 'auth/cancelled-popup-request') {
          alert("Popup Google sign in was canceled");
      }
      else if (errorCode === 'auth/operation-not-allowed') {
          alert("Operation is not allowed");
      }
      else if (errorCode === 'auth/operation-not-supported-in-this-environment') {
          alert("Operation is not supported in this environment");
      }
      else if (errorCode === 'auth/popup-blocked') {
          alert("Sign in popup got blocked");
      }
      else if (errorCode === 'auth/popup-closed-by-user') {
          alert("Google sign in popup got cancelled");
      }
      else if (errorCode === 'auth/unauthorized-domain') {
          alert("Unauthorized domain");
      }
       else {
        console.error(error);
      }
      // [END_EXCLUDE]
    });
    // [END signin]
  } else {
    // [START signout]
    firebase.auth().signOut();
    // [END signout]
  }
  // [START_EXCLUDE]
  document.getElementById('quickstart-sign-ing').disabled = false;
  // [END_EXCLUDE]
}

Answer 1

Get the email and password from user and then pass the values to signInWithEmailAndPassword, if some error occurs it will print the message, if not Firebase will successfully sign the user in.

firebase.auth().signInWithEmailAndPassword(email, password).catch(function(error) {
    // Handle Errors here.
    var errorCode = error.code;
    console.log(error.Message);

});

You also need a listener that handles login and logout status. This is where you can redirect users if they have successfully logged in.

To handle login and logout, always use onAuthStateChanged()

//Handle Account Status
firebase.auth().onAuthStateChanged(user => {
  if(user) {
    window.location = 'home.html'; //After successful login, user will be redirected to home.html
  }
});

The moment someone logins, user will be populated with user details and you can use it to redirect to another page.