Firebase auth flutter - firebase

Question

For user logged in
Future<String> signInWithGoogle() async {
final GoogleSignInAccount googleSignInAccount = await googleSignIn.signIn();
final GoogleSignInAuthentication googleSignInAuthentication =
await googleSignInAccount.authentication;
final AuthCredential credential = GoogleAuthProvider.getCredential(
accessToken: googleSignInAuthentication.accessToken,
idToken: googleSignInAuthentication.idToken,
);
final AuthResult authResult = await _auth.signInWithCredential(credential);
final FirebaseUser user = authResult.user;
assert(!user.isAnonymous);
assert(await user.getIdToken() != null);
final FirebaseUser currentUser = await _auth.currentUser();
assert(user.uid == currentUser.uid);
if(authResult.additionalUserInfo.isNewUser == true){
InsertNewUserDetails(user.displayName,user.email,user.photoUrl,user.phoneNumber);
}
if(authResult.user != null){
email = user.email;
name = user.displayName;
imageUrl =user.photoUrl;
globalInstance.isLoggedIn = true;
print(globalInstance.isLoggedIn);
}
return 'signInWithGoogle succeeded: $user';
}
This first time sign in Loginpage checking for is logged account
class MyApp extends StatelessWidget {
#override
String strinbggg;
Widget build(BuildContext context) {
// TODO: implement build
return MaterialApp(
home: Scaffold(
backgroundColor: Colors.teal,
body: StreamBuilder<FirebaseUser>(
stream: FirebaseAuth.instance.onAuthStateChanged,
builder: (BuildContext context, snapshot) {
if (snapshot.hasData && (!snapshot.data.isAnonymous)) {
// return Text('${snapshot.hasData}');
return Homepage();
} else {
// return SafeArea(
// maintainBottomViewPadding: true,
// child: Text('aasdasdfasfdh : ${snapshot.data.email}',style: TextStyle(color: Colors.black54),));
return LoginPage();
}
},
),
),
);
}
}
When first time login with google its working. When i was close application and start again it will redirecting to the homepage fine but user profile details like displayName , email are returning null value
signInwithgoogle() is use for the first time login that store the user details in firestore and user details set from here
MyApp is starting point of application that will check is user is already logged in

Answer 1

I would suggest, you check the user is already signed in or not using the method
bool isSignedIn = await _googleSignIn.isSignedIn();
and if the user is signed in, then get the credentials using
user = await _auth.currentUser();
when you start the app. In case you are not logged in, show login page. Any example would be something like below
final auth = FirebaseAuth.instance;
class MyApp extends StatelessWidget {
#override
String strinbggg;
Widget build(BuildContext context) {
return MaterialApp(
home: (_isSignedIn() == true ? new Homepage() : new LoginPage()));
}
bool _isSignedIn() async {
bool isSignedIn = await _googleSignIn.isSignedIn();
if(isSignedIn){
GoogleSignInAccount user = await auth.currentUser;
//You can store this in your state.
}
return !(user == null && auth.currentUser == null);
}
}
Please note this is a in editor composed code, not tested, you will have to make adjustments.