Solve PlatformException (PlatformException(user-not-found)) Firebase - firebase

Question

I don't know how to handle this exception launched by Firebase.
Exception has occurred.
PlatformException (PlatformException(user-not-found, There is no user record corresponding `to this identifier. The user may have been deleted.,
{code: user-not-found, message: There is no user record corresponding to this identifier. The user may have been deleted.,
nativeErrorMessage: There is no user record corresponding to this identifier. The user may have been deleted., nativeErrorCode: 17011, additionalData: {}}, null)).
This is the code, it comes from "loginWithEmailAndPassword" :
Future<void> submit(
context, FirebaseAuth authF, String email, String password) async {
try {
final userCredential = await authF.signInWithEmailAndPassword(
email: email,
password: password,
);
return;
} on FirebaseException catch (e) {
if (Platform.isIOS) {
LogInCupertinoDialogue(context);
} else {
LogInAndroidDialogue(context);
}
return;
}
}
User doesn't exists, this is what I need to handle.
EDIT : For "handle" I mean that if a non registered user try to login my app crashes. I don't want it! If it should crash just launch the window dialogue.

Answer 1

If I correctly understand your question, the following should do the trick:
} on FirebaseException catch (e) {
if (e.code == 'user-not-found') {
// Display the error message that user doesn't exists
} else {
// Display a more global error message
}
} ...
You can detect the code from the exception details:
PlatformException (PlatformException(user-not-found, There is no user
record corresponding `to this identifier. The user may have been
deleted., {code: user-not-found,...
Note: You'll find in the doc the list of the potential error codes returned by signInWithEmailAndPassword().

Answer 2

you can use exception code to detect different exception then use a dialog for showing it to user here is a simple example:-
Future<User> signin(String email, String password, BuildContext context) async {
await Firebase.initializeApp();
try {
UserCredential result =
await auth.signInWithEmailAndPassword(email: email, password: email);
User user = result.user;
return Future.value(user);
} catch (e) {
print(e.code);
switch (e.code) {
case 'ERROR_INVALID_EMAIL':
showErrDialog(context, e.code);
break;
case 'ERROR_WRONG_PASSWORD':
showErrDialog(context, e.code);
break;
case 'ERROR_USER_NOT_FOUND':
showErrDialog(context, e.code);
break;
case 'ERROR_USER_DISABLED':
showErrDialog(context, e.code);
break;
case 'ERROR_TOO_MANY_REQUESTS':
showErrDialog(context, e.code);
break;
case 'ERROR_OPERATION_NOT_ALLOWED':
showErrDialog(context, e.code);
break;
}
showErrDialog(BuildContext context, String err) {
FocusScope.of(context).requestFocus(new FocusNode());
return showDialog(
context: context,
child: AlertDialog(
title: Text("Error"),
content: Text(err),
actions: <Widget>[
OutlineButton(
onPressed: () {
Navigator.pop(context);
},
child: Text("Ok"),
),
],
),
);
}
}

Answer 3

change the platformExeption with FirebaseException
} on FirebaseException catch (err) {
var message = "An error occurred, please check your credential";
if (err.message != null) {
message = err.message;
}
print("error message : $message");
ScaffoldMessenger.of(ctx).showSnackBar(
SnackBar(
content: Text(message),
backgroundColor: Theme.of(ctx).errorColor,
),
);