FirebaseUser not an existing class | authentication errors [duplicate] - firebase

Question

I'm new to Flutter. I have an Issue with Firebase Auth/ Google Auth
The FirebaseUser is not defined
Code:
FirebaseAuth _auth = FirebaseAuth.instance;
GoogleSignIn googleSignIn = GoogleSignIn();
Future<FirebaseUser> currentUser() async { // The Issue is here in the Future<>
final GoogleSignInAccount account = await googleSignIn.signIn();
final GoogleSignInAuthentication authentication =
await account.authentication;
final GoogleAuthCredential credential = GoogleAuthProvider.getCredential(
idToken: authentication.idToken, accessToken: authentication.accessToken);
final AuthResult authResult = await _auth.signInWithCredential(credential);
final FirebaseUser user = authResult.user; // and here as I can't define this FirebaseUser object to return
return user;
}
Pubspec.yml
dependencies:
flutter:
sdk: flutter
cupertino_icons: ^0.1.3
firebase_auth: ^0.18.0
location: ^3.0.2
page_transition: ^1.1.6
google_sign_in: ^4.5.1
flutter_facebook_login: ^3.0.0
firebase_database: ^4.0.0
I also face the same issue with AuthResult
final AuthResult authResult = await _auth.signInWithCredential(credential);

Answer 1

Starting from Version firebase_auth 0.18.0:
In the newest version of firebase_auth, the class FirebaseUser was changed to User, and the class AuthResult was changed to UserCredential. Therefore change your code to the following:
Future<User> currentUser() async {
final GoogleSignInAccount account = await googleSignIn.signIn();
final GoogleSignInAuthentication authentication =
await account.authentication;
final GoogleAuthCredential credential = GoogleAuthProvider.credential(
idToken: authentication.idToken,
accessToken: authentication.accessToken);
final UserCredential authResult =
await _auth.signInWithCredential(credential);
final User user = authResult.user;
return user;
}
FirebaseUser changed to User
AuthResult changed to UserCredential
GoogleAuthProvider.getCredential() changed to GoogleAuthProvider.credential()
onAuthStateChanged which notifies about changes to the user's sign-in state was replaced with authStateChanges()
currentUser() which is a method to retrieve the currently logged in user, was replaced with the property currentUser and it no longer returns a Future<FirebaseUser>.
Example of the above two methods:
FirebaseAuth.instance.authStateChanges().listen((event) {
print(event.email);
});
And:
var user = FirebaseAuth.instance.currentUser;
print(user.uid);
Deprecation of UserUpdateInfo class for firebaseUser.updateProfile method.
Example:
Future updateName(String name, FirebaseUser user) async {
var userUpdateInfo = new UserUpdateInfo();
userUpdateInfo.displayName = name;
await user.updateProfile(userUpdateInfo);
await user.reload();
}
now
import 'package:firebase_auth/firebase_auth.dart' as firebaseAuth;
Future updateName(String name, auth.User firebaseUser) async {
firebaseUser.updateProfile(displayName: name);
await firebaseUser.reload();
}

Answer 2

Since firebase_auth 0.18.0, the class FirebaseUser was changed to User

Answer 3

In the newest version of firebase_auth, the class FirebaseUser was changed to User, and the class AuthResult was changed to UserCredentail. Therefore change FirebaseUser to User

Answer 4

The class FirebaseUser was changed to User
try this way
_registerUser() async {
try {
final User? user =
(await FirebaseAuth.instance.signInWithEmailAndPassword(
email: emailCtrl.text,
password: passCtrl.text,
))
.user;
FirebaseFirestore.instance.collection('users').doc().set({
'name': nameCtrl.text,
'uid': user!.uid,
'email': user.email,
'isEmailVerified': user.emailVerified, // will also be false
'photoUrl': user.photoURL, // will always be null
});
print("Created");
} catch (e) {
print(e.toString());
}
}

Answer 5

Run
flutter pub get
Then rebuild your app.

Answer 6

This can be your signin function with email and password as of Sept 2020.Initialze app is a new introduced method we must at least call once before we use any other firebase methods.
Future<void> signin() async {
final formState = _formkey.currentState;
await Firebase.initializeApp();
if (formState.validate()) {
setState(() {
loading = true;
});
formState.save();
try {
print(email);
final User user = (await FirebaseAuth.instance
.signInWithEmailAndPassword(email: email, password: password))
.user;
} catch (e) {
print(e.message);
setState(() {
loading = false;
});
}
}
}