Hello I have old code working before null safety, after migration and firebase upgrade, I can’t anymore login to an account.
I have take care to register before login, all my firebase setup is OK but
When I try to print("${user?.email} or print("${user?.displayName} or print("${user?.emailVerified} It return null
Here is my code
First I have a FuturBuilder who call _initializeFirebase()
FutureBuilder(
future: _initializeFirebase(),
Future<FirebaseApp> _initializeFirebase() async {
FirebaseApp firebaseApp = await Firebase.initializeApp();
_currentUser = FirebaseAuth.instance.currentUser!.emailVerified;
User? user = FirebaseAuth.instance.currentUser;
return firebaseApp;
}
After I have a raised button who call signInUsingEmailPassword
new RaisedButton(
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
elevation: 5,
highlightElevation: 10,
color: Color(0xffff9a7b),
splashColor: Colors.white,
child :
new Text("Charger mes données",textAlign: TextAlign.center, style: TextStyle(color: Colors.white, fontWeight: FontWeight.w500, fontSize:15)),
padding: const EdgeInsets.all (15.0),
onPressed: () async{
_focusEmail.unfocus();
_focusPassword.unfocus();
if(_currentUser==false){
if (_formKey.currentState!
.validate()) {
setState(() {
_isProcessing = true;
});
User? user = await signInUsingEmailPassword(
email: _emailTextController.text.replaceAll(' ', ''),
password:
_passwordTextController.text.replaceAll(' ', ''),
);
setState(() {
_isProcessing = false;
});
}
}
},
),
After I have error , print("$user user"); return Unhandled Exception: Null check operator used on a null value
Future<User?> signInUsingEmailPassword({
String? email,
String? password,
}) async {
FirebaseAuth auth = FirebaseAuth.instance;
User? user;
print("$user user");
try {
UserCredential userCredential = await auth.signInWithEmailAndPassword(
email: email!,
password: password!,
);
user = userCredential.user;
} on FirebaseAuthException catch (e) {
if (e.code == 'user-not-found') {
print('No user found for that email.');
showDialog(
context: context,
builder: (context) {
return AlertDialog(
title: Text('Erreur'),
content: Text("Email incorrect"),
);
});
} else if (e.code == 'wrong-password') {
print('Erreur de mot de passe.');
showDialog(
context: context,
builder: (context) {
return AlertDialog(
title: Text('Erreur'),
content: Text("Mot de passe incorrect"),
);
});
}
}
return user;
}
>Solution :
Instead of using !try using ? By adding an exclamation you mention that its not null but value is unknown. By adding a ? You mean that it maybe or maynot be null
print("${user?.email});
It also means that the user is null. Maybe there is some error in the firebase initialisation