Flutter/Firebase: Dynamic homepage depending on user loginStatus using MultiProvider issues - firebase

Question

I want to check if the user is already logged in and show him page depending on that.
Here is my main.dart:
...
import 'firebase/authentication_service.dart';
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
Provider<AuthenticationService>(
create: (_) => AuthenticationService(FirebaseAuth.instance),
),
StreamProvider(
create: (context) =>
context.read<AuthenticationService>().authStateChanges,
initialData: null,
),
],
child: MaterialApp(
debugShowCheckedModeBanner: false,
theme: ThemeData(
backgroundColor: Colors.transparent,
primaryColor: Color(0xff4d629f),
buttonBarTheme:
ButtonBarThemeData(alignment: MainAxisAlignment.center)),
home: AuthenticationWrapper(),
),
);
}
}
class AuthenticationWrapper extends StatelessWidget {
#override
Widget build(BuildContext context) {
final firebaseUser = context.watch<User>();
if (firebaseUser != null) {
//If the user is successfully Logged-In.
return HomePage();
} else {
//If the user is not Logged-In.
return LoginPage();
}
}
}
And here is my Authentication_service.dart:
class AuthenticationService {
final FirebaseAuth _firebaseAuth;
UserModel userModel = UserModel.empty();
final userRef = FirebaseFirestore.instance.collection('users');
AuthenticationService(this._firebaseAuth);
Stream<User?> get authStateChanges => _firebaseAuth.authStateChanges();
Future<String> signIn(
{required String email, required String password}) async {
try {
await _firebaseAuth.signInWithEmailAndPassword(
email: email, password: password);
return "Signed in";
} on FirebaseAuthException catch (e) {
if (e.code == 'user-not-found')
return "There is no user for that e-mail";
else if (e.code == 'wrong-password')
return "Entered wrong Password";
else
return "Something went wrong: $e";
}
}
...
And there are errors:
The following ProviderNotFoundException was thrown building AuthenticationWrapper(dirty):
Error: Could not find the correct Provider above this AuthenticationWrapper Widget
This happens because you used a BuildContext that does not include the provider
of your choice. There are a few common scenarios:
You added a new provider in your main.dart and performed a hot-reload.
To fix, perform a hot-restart.
The provider you are trying to read is in a different route.
Providers are "scoped". So if you insert of provider inside a route, then
other routes will not be able to access that provider.
You used a BuildContext that is an ancestor of the provider you are trying to read.
Make sure that AuthenticationWrapper is under your MultiProvider/Provider.
This usually happens when you are creating a provider and trying to read it immediately.
For example, instead of:
Widget build(BuildContext context) {
return Provider<Example>(
create: (_) => Example(),
// Will throw a ProviderNotFoundError, because `context` is associated
// to the widget that is the parent of `Provider<Example>`
child: Text(context.watch<Example>()),
),
}
consider using builder like so:
Widget build(BuildContext context) {
return Provider<Example>(
create: (_) => Example(),
// we use `builder` to obtain a new `BuildContext` that has access to the provider
builder: (context) {
// No longer throws
return Text(context.watch<Example>()),
}
),
}
Unfortunately it didn't help or i just can't implement it in a right way.

Answer 1

#SumerSingh solution worked, i just changed it a bit for my use.
void main() {
WidgetsFlutterBinding.ensureInitialized();
runApp(MyApp());
}
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
bool _initialized = false;
bool _error = false;
void initializeFlutterFire() async {
try {
await Firebase.initializeApp();
setState(() {
_initialized = true;
});
} catch (e) {
setState(() {
_error = true;
});
}
}
#override
void initState() {
initializeFlutterFire();
super.initState();
}
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'App',
debugShowCheckedModeBanner: false,
home: Scaffold(
body: _error
? splashScreen()
: !_initialized
? splashScreen()
: SplashScreen()));
}
}
class SplashScreen extends StatefulWidget {
SplashScreen({Key? key}) : super(key: key);
#override
_SplashScreenState createState() => _SplashScreenState();
}
class _SplashScreenState extends State<SplashScreen> {
final FirebaseAuth _auth = FirebaseAuth.instance;
var currentUser;
AuthenticationService _authService =
new AuthenticationService(FirebaseAuth.instance);
late final UserModel userModel;
bool isAuthinticated = false;
_isUserSignedin() async {
currentUser = _auth.currentUser;
userModel = await _authService.getUserFromDB(uid: _auth.currentUser!.uid);
setState(() {
currentUser != null ? isAuthinticated = true : isAuthinticated = false;
});
}
#override
void initState() {
super.initState();
_isUserSignedin();
startTime();
}
startTime() async {
var _duration = new Duration(seconds: 4);
return new Timer(_duration, navigationPage);
}
Widget userAuthState() {
if (!isAuthinticated)
return LoginPage();
else if (userModel.type == 'Attendant')
return AttendantMainPage();
else
return SeniorMainPage();
}
void navigationPage() {
Navigator.pushReplacement(
context,
MaterialPageRoute(builder: (BuildContext context) => userAuthState()),
);
}
#override
Widget build(BuildContext context) {
return Scaffold(body: splashScreen());
}
}
Widget splashScreen() {
return Container(
height: double.maxFinite,
width: double.maxFinite,
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisSize: MainAxisSize.max,
children: [
CircleAvatar(
radius: 80.0, child: Image.asset('assets/logo.png')),
Text("APP NAME",
style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold)),
CircularProgressIndicator()
]),
);
}
It works well, thank you for help!