Firebase OnMessage function refreshes widget - flutter

Question

I am using firebase cloud messaging to push notification on my app that contains a chat page.
I defined my firebase push functions on my main.dart as below:
_firebaseMessaging.configure(
onMessage: (Map<String, dynamic> message) async {
print("onMessage: $message");
//_showItemDialog(message);
},
onBackgroundMessage: myBackgroundMessageHandler,
onLaunch: (Map<String, dynamic> message) async {
print("onLaunch: $message");
//_navigateToItemDetail(message);
},
onResume: (Map<String, dynamic> message) async {
print("onResume: $message");
//_navigateToItemDetail(message);
},
);
When chat widget opened and i receive a push notification, my OnMessage method is reached normally.
The question is: what is the best way to refresh my chat page considering that the opened page is not the same one where the reached OnMessage function is declared?

Answer 1

I have used following peice of code for different question on StackOverflow. But the problem there is entirely different from yours, so pasting relevant code.
You can use BLOC here. FCM/NotificationService will send notifications to BLOC/NotificationsBloc and all the widgets that need notifications can subscribe for the notifications. Sample implementation
BLOC
import 'package:rxdart/rxdart.dart';
class LocalNotification {
final String type;
final Map data;
LocalNotification(this.type, this.data);
}
class NotificationsBloc {
NotificationsBloc._internal();
static final NotificationsBloc instance = NotificationsBloc._internal();
final BehaviorSubject<LocalNotification> _notificationsStreamController = BehaviorSubject<LocalNotification>();
Stream<LocalNotification> get notificationsStream {
return _notificationsStreamController;
}
void newNotification(LocalNotification notification) {
_notificationsStreamController.sink.add(notification);
}
void dispose() {
_notificationsStreamController?.close();
}
}
FCM Listener (NotificationService)
import 'package:firebase_messaging/firebase_messaging.dart';
import 'notifications_bloc.dart';
class LocalNotificationService {
final FirebaseMessaging _firebaseMessaging = FirebaseMessaging();
bool _started = false;
LocalNotificationService._internal();
static final LocalNotificationService instance = LocalNotificationService._internal();
// ********************************************************* //
// YOU HAVE TO CALL THIS FROM SOMEWHERE (May be main widget)
// ********************************************************* //
void start() {
if (!_started) {
_start();
_started = true;
_refreshToken();
}
}
void _refreshToken() {
_firebaseMessaging.getToken().then(_tokenRefresh, onError: _tokenRefreshFailure);
}
void _start() {
_firebaseMessaging.requestNotificationPermissions();
_firebaseMessaging.onTokenRefresh.listen(_tokenRefresh, onError: _tokenRefreshFailure);
_firebaseMessaging.configure(
onMessage: _onMessage,
onLaunch: _onLaunch,
onResume: _onResume,
);
}
void _tokenRefresh(String newToken) async {
print(" New FCM Token $newToken");
}
void _tokenRefreshFailure(error) {
print("FCM token refresh failed with error $error");
}
Future<void> _onMessage(Map<String, dynamic> message) async {
print("onMessage $message");
if (message['notification'] != null) {
final notification = LocalNotification("notification", message['notification'] as Map);
NotificationsBloc.instance.newNotification(notification);
return null;
}
if (message['data'] != null) {
final notification = LocalNotification("data", message['data'] as Map);
NotificationsBloc.instance.newNotification(notification);
return null;
}
}
Future<void> _onLaunch(Map<String, dynamic> message) {
print("onLaunch $message");
return null;
}
Future<void> _onResume(Map<String, dynamic> message) {
print("onResume $message");
return null;
}
}
Finally in your Widget
Stream<LocalNotification> _notificationsStream;
#override
void initState() {
super.initState();
_notificationsStream = NotificationsBloc.instance.notificationsStream;
_notificationsStream.listen((notification) {
// TODO: Implement your logic here
print('Notification: $notification');
});
}
#override
void dispose() {
super.dispose();
}
Hope this is what you are looking for.