Flutter user redirect if logged in - flutter

Question

still a beginner in flutter. below is a sample chat apps i tried to redirect user depending on their login status.
so far tested with emulator, the outputs is what i expected. my questions are:
1.is this the correct approach for user redirect, or is there a better way as in better refactored code?
2.any refactoring can be done for the 'return materialApp', as it is very repetitive. (only changing initialRoute)
3.any implication to runApp a StatefulWidget? because all tutorial normally starts runApp a StatelessWidget
import 'package:flutter/material.dart';
import 'package:chatting/screens/login_screen.dart';
import 'package:chatting/screens/registration_screen.dart';
import 'package:chatting/screens/chat_screen.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'dart:async';
void main() => runApp(LoadPage());
class LoadPage extends StatefulWidget {
#override
_LoadPageState createState() => _LoadPageState();
}
class _LoadPageState extends State<LoadPage> {
Future checkIfLoggedIn;
#override
void initState() {
super.initState();
checkIfLoggedIn = FirebaseAuth.instance.currentUser();
}
#override
Widget build(BuildContext context) {
return FutureBuilder<FirebaseUser>(
future: checkIfLoggedIn,
builder: (BuildContext context, AsyncSnapshot<FirebaseUser> snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.none:
case ConnectionState.waiting:
return Center(
child: CircularProgressIndicator(
backgroundColor: Colors.lightBlueAccent,
),
);
default:
if (snapshot.hasData)
return MaterialApp(
debugShowCheckedModeBanner: false,
initialRoute: ChatScreen.id,
routes: {
ChatScreen.id: (context) => ChatScreen(),
LoginScreen.id: (context) => LoginScreen(),
RegistrationScreen.id: (context) => RegistrationScreen(),
},
);
else
return MaterialApp(
debugShowCheckedModeBanner: false,
initialRoute: LoginScreen.id,
routes: {
ChatScreen.id: (context) => ChatScreen(),
LoginScreen.id: (context) => LoginScreen(),
RegistrationScreen.id: (context) => RegistrationScreen(),
},
);
}
});
}
}

Answer 1

Yeah your code looks good to me. There's no problem using a StatefulWidget in runApp.
The only additional tip I'd give is that, typically, for larger applications, you'll want to use the BLoC pattern to manage state. If you added that pattern to this code sample, it would abstract the logic you're doing away from this component, and you could manage the future in the bloc. You could then use a stateless widget for your loading screen. The Flutter Bloc library provides useful, straightforward abstractions that show how to implement the bloc pattern.