CloudMessaging.dart

import 'dart:io';
import 'package:flutter/foundation.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:myapp/model/Message.dart';

class CloudMessaging {

  FirebaseMessaging firebaseMessaging;
  ValueChanged<Message> onReceived;

  CloudMessaging({
    @required this.onReceived
  });

  void initialize() {
    firebaseMessaging = FirebaseMessaging();
    messageListener();
  }

  Future<String> getToken(){
    return firebaseMessaging.getToken().then((token) {
      return token;
    });
  }
 
  static Future bgMsgHandler(Map<String, dynamic> message) async{
    if (message.containsKey('data')) {
      final dynamic data = message['data'];
      print('Data Message => $data');
    }

    if (message.containsKey('notification')) {
      final dynamic notification = message['notification'];
      print('Notification Message => $notification');
      
    }
  }

  void msgHandler(Map<String, dynamic> message){
    final dynamic notification = message['notification'];
    String nTitle = notification['title'] != null ? notification['title'] : '';
    String nBody = notification['body'] != null ? notification['body'] : '';
    String nImage = notification['image'] != null ? notification['image'] : '';
    Message msg = new Message(title:nTitle, body:nBody, image:nImage);
    onReceived(msg);
  }

  void messageListener() {

    if (Platform.isIOS) iosPermission();

    firebaseMessaging.configure(
      onMessage: (Map<String, dynamic> message) async {
        print('onMessage');
        msgHandler(message);
      },
      onBackgroundMessage: Platform.isAndroid ? bgMsgHandler:null,
      onResume: (Map<String, dynamic> message) async {
        print('onResume');
        msgHandler(message);
      },
      onLaunch: (Map<String, dynamic> message) async {
        print('onLaunch');
        msgHandler(message);
      },
    );

  }

  void iosPermission() {
    firebaseMessaging.requestNotificationPermissions(IosNotificationSettings(sound: true, badge: true, alert: true));
    firebaseMessaging.onIosSettingsRegistered.listen((IosNotificationSettings settings){
      print("FCM onIosSettingsRegistered");
      // print("Settings registered: $settings");
    });
  }

}

main.dart

import 'package:flutter/material.dart';
import 'package:fluro/fluro.dart';
import 'package:flutter/services.dart';
import 'package:myapp/routes/routes.dart';
import 'package:myapp/routes/application.dart';

class MyApp extends StatefulWidget {
  @override
  MyAppState createState() => MyAppState();
}

class MyAppState extends State<MyApp> {

  MyAppState() {
    final router = Router();
    Routes.configureRoutes(router);
    Application.router = router;
  }

  @override
  void initState() {
    super.initState();
  }

  Widget build(BuildContext context) {
    final app = MaterialApp(
      title: 'myapp',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      initialRoute : Routes.root,
      onGenerateRoute: Application.router.generator,
    );
    return app;
  }
}

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]).then((_) {
    runApp(new MyApp());
  });
}

Message.dart

import 'package:flutter/material.dart';

class Message{

  String title,body,image;

  Message({
    @required this.title,
    @required this.body,
    this.image,
  });

  String getTitle() => this.title;
  void setTitle(title) => this.title = title;

  String getBody() => this.body;
  void setBody(body) => this.body = body;

  String getImage() => this.image;
  void setImage(image) => this.image = image;

}

root.dart

import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:myapp/config/Messaging.dart';
import 'package:myapp/model/Message.dart';
import 'package:myapp/screens/auth/main.dart';
import 'package:myapp/screens/index.dart';
import 'package:myapp/service/auth.dart';
import 'package:myapp/service/index.dart';
import 'package:myapp/components/Loader.dart';
import 'package:myapp/config/Store.dart';

class LandingPage extends StatefulWidget {
  @override
  LandingPageState createState() => LandingPageState();
}

class LandingPageState extends State<LandingPage> {
  StreamBuilder<FirebaseUser> builder;
  final FBService fbService = new FBService();
  final AuthService auth = AuthService();

  CloudMessaging messaging = new CloudMessaging(
    onReceived: (Message msg){
      print(msg.getTitle());
    }
  );

  Store store = new Store();

  @override
  void initState() {
    super.initState();
    messaging.initialize();
  }

  Future<String> getRole(uid) async {
    Map checkRole = await fbService.checkUser(uid);
    return checkRole['type'];
  }
 

  void showMessageDialog(){ // Show Dialog onMessage Received
    // showDialog(
    //   context: context,
    //   barrierDismissible: false,
    //   builder: (BuildContext context) => buildDialog(context)
    // );
  }

  @override
  Widget build(BuildContext context) {

    builder = new StreamBuilder(
      stream: FirebaseAuth.instance.onAuthStateChanged,
      builder: (context, snapshot) {
        if (snapshot.connectionState == ConnectionState.active) {
          FirebaseUser user = snapshot.data;
          if (user == null) {
            return MainLogin();
          }
          messaging.getToken().then((token) {
            print('Token => $token');
            auth.setToken(user.uid, token);
            store.updateToken(token);
          });

          return FutureBuilder(
            future: getRole(user.uid),
            builder: (BuildContext context, AsyncSnapshot mSnapshot) {
              if (mSnapshot.connectionState == ConnectionState.done) {
                String role = mSnapshot.data;
                if (role == 'admin') {
                  return AdminIndex(uID: user.uid);
                } else if (role == 'shop') {
                  return ShopIndex(uID: user.uid);
                } else if (role == 'hub') {
                  return HubIndex(uID: user.uid);
                } else if (role == 'rider') {
                  return RiderIndex(uID: user.uid);
                } else {
                  return Loader();
                }
              } else {
                return Loader();
              }
            },
          );

        } else {
          return Loader();
        }
      }
    );

    return Scaffold(
      body: builder,
    );
  }

  @override
  void dispose() {
    super.dispose();
  }
}