Sign In user function from documentation doesn't work Flutter - firebase

Question

I had some troubles with the SignInWithEmailAndPassword Firebase method.
When a non registered user tries to signIn (he should create a new user before) Firebase, rightly, throw an error but the problem is that this error freezes my app so I need to catch it but I don't know why also when I catch the error (or at least I think I caught it) the app freezes so I opened the documentation and found this code :
try {
UserCredential userCredential = await FirebaseAuth.instance.signInWithEmailAndPassword(
email: "barry.allen#example.com",
password: "SuperSecretPassword!"
);
} on FirebaseAuthException catch (e) {
if (e.code == 'user-not-found') {
print('No user found for that email.');
} else if (e.code == 'wrong-password') {
print('Wrong password provided for that user.');
}
}
Well I copy-pasted it to see if the error handling works fine because obviously this call will throw an error but also this freezes my app. The I tried to read the doc and I found that the "Error Handling" section is missing missing doc.
Someone told me that I "need to learn javascript" well ok maybe I'm missing something but also a common error can be hard to solve for who doesn't know it, so I will write my previous code below to show you :
Future<void> submit(
context, FirebaseAuth authF, String email, String password) async {
try {
UserCredential userCredential =
await FirebaseAuth.instance.signInWithEmailAndPassword(
email: email,
password: password,
);
} on FirebaseAuthException catch (e) {
if (e.code == 'user-not-found') {
print('No user found for that email.');
} else if (e.code == 'wrong-password') {
print('Wrong password provided for that user.');
} else {
print(e);
}
} catch (e) {
if (Platform.isIOS) {
LogInCupertinoDialogue(context,e);
} else {
LogInAndroidDialogue(context,e);
}
}
}
This function is called by :
Future<void> _submit(Auth auth, FirebaseAuth authF) async {
//Create Artist and send it to the database
if (_validateAndSaveForm()) {
try {
//await submit(context, authF, emailF, password);
submit(context, authF, emailF, password);
//Dovrebbe andare in home page ma per ora va bene così
} catch (e) {
if (Platform.isIOS) {
LogInCupertinoDialogue(context,e);
} else {
LogInAndroidDialogue(context,e);
}
}
}
}

Answer 1

Just use the below code. It has following functions:-
signin()
signUp()
showErrDialog()
FirebaseAuth auth = FirebaseAuth.instance;
final googleSignIn = GoogleSignIn();
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"),
),
],
),
);
}
Future<User> signUp(
String email, String password, String eno, BuildContext context) async {
await Firebase.initializeApp();
try {
UserCredential result = await auth.createUserWithEmailAndPassword(
email: email, password: email);
User user = result.user;
print("user is :" + user.email + " id is :" + user.uid);
return Future.value(user);
} catch (error) {
switch (error.code) {
case 'ERROR_EMAIL_ALREADY_IN_USE':
showErrDialog(context, "Email Already Exists");
break;
case 'ERROR_INVALID_EMAIL':
showErrDialog(context, "Invalid Email Address");
break;
case 'ERROR_WEAK_PASSWORD':
showErrDialog(context, "Please Choose a stronger password");
break;
}
return Future.value(null);
}
}