How to Navigate without context in flutter? - flutter

Question

I ended up with using a static function but I need to do navigation and It gave me an error that no getter was found for context so I looked for a solution and found the GET package but when I tried to use it It gave me another error :
E/flutter ( 6078): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)]
Unhandled Exception: NoSuchMethodError: The method 'push' was called on null.
My code:
void main() {
runApp(MyApp());
_MyAppState.autologin();
}
class _MyAppState extends State<MyApp> {
static autologin() async {
var userType;
var store = Firestore.instance;
var auth = FirebaseAuth.instance;
final FirebaseUser user = await auth.currentUser();
store.collection('Users').document(user.uid).get().then((value) {
userType = (value.data)['userType'];
if (userType == 'Student') {
Get.to(StudentsPage());
} else if (userType == 'Teacher') {
} else if (userType == 'Admin') {}
});
}

Answer 1

Create a navigator key
final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();
Assign it to MaterialApp
MaterialApp(
home: Home(),
navigatorKey: navigatorKey
),
Then push your routes by navigatorKey below
navigatorKey.currentState.push(MaterialPageRoute(
builder: (context) => AnotherPage(),
));
or
navigatorKey.currentState.pushNamed(routeName);

Answer 2

This solution is general if you want to navigate or to show Dialog without context using globalKey especially with Bloc or when your logic is separated from your UI part.
Firstly install this package:
Note: I'm using null safety version
get_it: ^7.2.0
Then create a separate file for your service locator:
service_location.dart
import 'package:get_it/get_it.dart';
GetIt locator = GetIt.instance;
class NavigationService {
final GlobalKey<NavigatorState> navigatorKey =
new GlobalKey<NavigatorState>();
Future<dynamic> navigateTo(String routeName) {
return navigatorKey.currentState!.pushNamed(routeName);
}
void setupLocator() {
locator.registerLazySingleton(() => NavigationService());
}
void showMyDialog() {
showDialog(
context: navigatorKey.currentContext!,
builder: (context) => Center(
child: Material(
color: Colors.transparent,
child: Text('Hello'),
),
));
}
}
on main.dart:
void main() {
WidgetsFlutterBinding.ensureInitialized();
NavigationService().setupLocator();
runApp(MyApp());
}
// add navigatorKey for MaterialApp
MaterialApp(
navigatorKey: locator<NavigationService>().navigatorKey,
),
at your business logic file bloc.dart
define this inside the bloc class or at whatever class you want to use navigation inside
Then start to navigate inside any function inside.
class Cubit extends Cubit<CubitState> {
final NavigationService _navigationService = locator<NavigationService>();
void sampleFunction(){
_navigationService.navigateTo('/home_screen'); // to navigate
_navigationService.showMyDialog(); // to show dialog
}
}
Not: I'm using generateRoute for routing.