Flutter Firebase messaging: sending a user to a specific screen - flutter

Question

Im trying to work with firebase messaging on flutter, and here's the situation. I have push notification implemented simply with the following:
void main() async {
WidgetsFlutterBinding();
await Firebase.initializeApp(
options: DefaultFirebaseOptions.currentPlatform,
);
FirebaseMessaging.onMessage.listen((RemoteMessage message) {
print('Got a message whilst in the foreground!');
print('Message data: ${message.data}');
if (message.notification != null) {
print('Message also contained a notification: ${message.notification}');
}
});
FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
// await _configureFirebaseAuth();
// await _configureFirebaseStorage();
// _configureFirebaseFirestore();
runApp(const MyApp());
}
Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
print("Handling a background message: ${message.messageId}");
}
This allows the push notifications to appear, but there is no real functionality to it. In my case, i would like to call navigator and push a certain route. Since this requires context, I placed the following method in my home page(the first screen actually built in the app):
#override
void initState() {
// TODO: implement initState
handleMessageOnBackground();
super.initState();
}
void handleMessageOnBackground() {
FirebaseMessaging.instance.getInitialMessage().then(
(remoteMessage) {
if (remoteMessage != null) {
print('Message: ${remoteMessage.data}');
RemoteMessage? message = remoteMessage;
}
},
);
}
The idea is that, in the initstate method, i now have context, so I would be able to Navigate to a different page. While this works(to my understanding) when the app is completely closed, it will not cover the cases when remote notifications are caught by the .onMessage or the .onBackgroundMessage. Is there any way to pass NotificationMessages from the top of my app down into the main page to use for navigation?
Thank you!

Answer 1

If you want to navigate without context use a GlobalKey.
Define a Globalkey //not inside any class
final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();
and inside your MaterialAppWidget()
MaterialApp(
navigatorKey: navigatorKey,
...
);
From firebase you'll receive some data in _firebaseMessagingBackgroundHandler(){}
based on that data you can navigate to any screen.
//if you are creating a notification using that data then put required data in payload of that notification. so you can receive that payload when you tap on that notification that will help you to navigate to a specific screen.
so navigate without context like this.
navigatorKey.currentState
?.pushNamed(AnotherScreen.routeName);
if you want to pass arguments
navigatorKey.currentState
?.pushNamed(IOSNotificationIntentScreen.routeName, arguments: {
"arg1": "hello arg 1",
"arg2": "hello arg 2",
});