firebase_messaging: Normal Push Notifications appear silently or not at all when the flutter app is terminated

[royibernthal]

My flutter doctor is perfect.

I'm using firebase-admin on nodejs to send push notifications to users:
https://firebase.google.com/docs/admin/setup

I'm using firebase_messaging 6.0.13 on flutter:
https://pub.dev/packages/firebase_messaging

I'm trying to send a push notification with the highest priority on both android and ios.

    firebase.messaging(firebaseApp).send({
    	token,
    	notification,
    	android: { priority: 'high' },
    	apns: { headers: { 'apns-priority': '10' }, payload: { aps: { sound: 'default' } } },
    	data
    }

On my development devices it works like a charm both when the app is in the background and when it's terminated.

I'm receiving push notifications that visibly pop and make a sound 100% of the time, on both android and ios.

The issue is on other devices -

If the app is in the background, I can sometimes see an actual push notification visibly pop, and make a sound as it should. Sometimes not.

If the app is terminated, a push notification is received - but it doesn't visibly pop nor make a sound, I can only see it if I scroll down the menu from the top of the screen, it's listed as a received push notification.
Sometimes the notification is not receieved at all.

I tried to change the priority of notifications from my app to high on the actual device as well, but it didn't change anything.

My users keep complaining that they're not receiving push notifications - I'm guessing they either actually don't receieve them or simply don't see them since they're recieved silently as I described above.

I literally have no idea what's going on and why it doesn't work as it should on devices other than my own development devices.

Any ideas?

[TahaTesser]

Hi @royibernthal
Is the issue on other devices are just android or both iOS and Android?
can you please provide your flutter doctor -v and flutter run --verbose?
Can you please your MainActivity and build.gradle?
Also, to better address the issue, would be helpful if you could post a minimal code sample to reproduce the problem
Thank you

[royibernthal]

Hi @TahaTesser

The issue is on both iOS and Android.

flutter doctor -v on the machine that compiles for android

[√] Flutter (Channel stable, v1.17.1, on Microsoft Windows [Version 10.0.18363.836], locale en-US)
    • Flutter version 1.17.1 at D:\flutter
    • Framework revision f7a6a7906b (9 days ago), 2020-05-12 18:39:00 -0700
    • Engine revision 6bc433c6b6
    • Dart version 2.8.2


[√] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
    • Android SDK at C:\Users\royib\AppData\Local\Android\Sdk
    • Platform android-29, build-tools 29.0.3
    • ANDROID_HOME = C:\Users\royib\AppData\Local\Android\Sdk
    • Java binary at: D:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)
    • All Android licenses accepted.

[√] Android Studio (version 3.6)
    • Android Studio at D:\Program Files\Android\Android Studio
    • Flutter plugin version 45.1.1
    • Dart plugin version 192.8052
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)

I have a different machine for compiling ios, I can provide flutter doctor for that a bit later. There are no errors there though, is there other info you'd like to see there?

flutter run --verbose produces a very long log that gets cut in the terminal, is there any way for me to get the full log?

MainActivity.kt

package com.lumney

import androidx.annotation.NonNull;
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugins.GeneratedPluginRegistrant

class MainActivity: FlutterActivity() {
    override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
        GeneratedPluginRegistrant.registerWith(flutterEngine);
    }
}

android/build.gradle

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        google()
        jcenter()
        maven {
            url 'https://maven.fabric.io/public'
        }
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath 'com.google.gms:google-services:4.3.2'
        classpath 'io.fabric.tools:gradle:1.26.1'
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

rootProject.buildDir = '../build'
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
    project.evaluationDependsOn(':app')
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

android/app/build.gradle

def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader('UTF-8') { reader ->
        localProperties.load(reader)
    }
}

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
    flutterVersionCode = '1'
}

def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
    flutterVersionName = '1.0'
}

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
apply plugin: 'io.fabric'
apply plugin: 'com.google.gms.google-services'

def keystoreProperties = new Properties()
def keystorePropertiesFile = rootProject.file('key.properties')
if (keystorePropertiesFile.exists()) {
    keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
}

android {
    compileSdkVersion 28

    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }

    lintOptions {
        disable 'InvalidPackage'
    }

    defaultConfig {
        applicationId "com.lumney"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    signingConfigs {
        release {
            keyAlias keystoreProperties['keyAlias']
            keyPassword keystoreProperties['keyPassword']
            storeFile keystoreProperties['storeFile'] ? file(keystoreProperties['storeFile']) : null
            storePassword keystoreProperties['storePassword']
        }
    }

    buildTypes {
        release {
            signingConfig signingConfigs.release
        }
    }
}

flutter {
    source '../..'
}

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'com.google.firebase:firebase-messaging:20.1.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
}

I'm not sure how I could post a minimal code sample to reproduce the problem without creating a separate app on both flutter and firebase and testing it on many devices, and that'd be a huge task. Correct me if I'm wrong.

[4tKnight]

Same issue I am having currently

[corvus89]

I have got the same problem. Push notifications show instantly on one iOS device (iPhone 5c, 10.3.3) and not at all if app is in background/terminated on other (iPhone 6S, 13.5). App was installed from the same archive through diawi in debug mode. On iPhone 6S onMessage() is called if app is in foreground or after resuming app.

It works fine both foreground and background on any Android I tested it on.

I won't be able to post flutter run --verbose because I'm working on commercial product. There is too much information reviled there and it is too long to anonymize it. If some can publish that kind of logs you can run flutter run --verbose | tee log.txt. It will save copy of console printed text to file.

[✓] Flutter (Channel stable, v1.17.1, on Mac OS X 10.15.4 19E287, locale en-GB)
    • Flutter version 1.17.1 at /Users/X/flutter
    • Framework revision f7a6a7906b (13 days ago), 2020-05-12 18:39:00 -0700
    • Engine revision 6bc433c6b6
    • Dart version 2.8.2

 
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
    • Android SDK at /Users/X/Library/Android/sdk
    • Platform android-R, build-tools 29.0.3
    • ANDROID_HOME = /Users/X/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b4-5784211)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 11.5)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 11.5, Build version 11E608c
    • CocoaPods version 1.8.4

[✓] Android Studio (version 3.6)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 45.1.1
    • Dart plugin version 192.7761
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b4-5784211)

[samueladekunle]

I am also experiencing the same issue on Android. When the app is in the foreground, notifications are handled in the onMessage handler. When the app is in the background, notifications appear in the system tray. But when the app is killed/terminated, nothing happens.

[wladrbarbosa]

Try to remove all notification attributes from the payload of send requests and use only the data attribute with default information like title and body. Maybe this will work. Something like this:

HTTP v1 version

{ "message": { "token": "DEVICE_TOKEN", "data": { "title": "title", "body": "body", "image": "IMAGE_URL", "click_action" : "FLUTTER_NOTIFICATION_CLICK" }, "android": { "priority" : "HIGH" }, "apns": { "headers": { "apns-priority": "10" } } } }

Legacy version

{ "to" : "DEVICE_TOKEN", "priority" : "high", "content_available" : true, "data" : { "body" : "body", "title": "title", "click_action" : "FLUTTER_NOTIFICATION_CLICK", "image" : "IMAGE_URL" } }

[royibernthal]

Try to remove all notification attributes from the push send and use only the data attribute with default information like title and body. Maybe this will work. Something like this:

HTTP v1 version

{ "message": { "token": "DEVICE_TOKEN", "data": { "title": "title", "body": "body", "image": "IMAGE_URL", "click_action" : "FLUTTER_NOTIFICATION_CLICK" }, "android": { "priority" : "HIGH" }, "apns": { "headers": { "apns-priority": "10" } } } }

Legacy version

{ "to" : "DEVICE_TOKEN", "priority" : "high", "content_available" : true, "data" : { "body" : "body", "title": "title", "click_action" : "FLUTTER_NOTIFICATION_CLICK", "image" : "IMAGE_URL" } }

Wouldn't omitting the notification key result in a data-only notification which by definition will not be visually displayed to the user?

Have you tried that?

[wladrbarbosa]

Yes, here is working. After remove the notification attribute you can use the plugin flutter_local_notifications to show a big picture notification in place, for example. But I haven't tested this on iOS.

[royibernthal]

Are you calling flutter_local_notifications in firebase_messaging's onBackgroundMessage?
If so, from my previous experience with it there are many problems with it, so I'm a bit hesitant.
If not, how do you use flutter_local_notifications when the app is terminated?

Also, shouldn't firebase_messaging just work on its own out of the box? I feel like it shouldn't be this complicated to receive push notifications.

[wladrbarbosa]

Here is my files:

NotificationsHandler.dart

import 'dart:async';
import 'dart:io';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter/material.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:http/http.dart';
import 'package:rxdart/rxdart.dart';
import 'package:path_provider/path_provider.dart';

// Streams are created so that app can respond to notification-related events since the plugin is initialised in the `main` function
final BehaviorSubject<ReceivedNotification> didReceiveLocalNotificationSubject =
    BehaviorSubject<ReceivedNotification>();

final BehaviorSubject<String> selectNotificationSubject =
    BehaviorSubject<String>();

class ReceivedNotification {
  final int id;
  final String title;
  final String body;
  final String payload;

  ReceivedNotification({
    @required this.id,
    @required this.title,
    @required this.body,
    @required this.payload,
  });
}

class SecondScreen extends StatefulWidget {
  SecondScreen(this.payload);

  final String payload;

  @override
  State<StatefulWidget> createState() => SecondScreenState();
}

class SecondScreenState extends State<SecondScreen> {
  String _payload;
  @override
  void initState() {
    super.initState();
    _payload = widget.payload;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('test')),
      body: Center(
        child: RaisedButton(
          onPressed: () {
            Navigator.pop(context);
          },
          child: Text('${(_payload ?? '')} Go back!'),
        ),
      ),
    );
  }
}

class NotificationsHandler {
  void _configureDidReceiveLocalNotificationSubject(BuildContext context) {
    didReceiveLocalNotificationSubject.stream
        .listen((ReceivedNotification receivedNotification) async {
      await showDialog(
        context: context,
        builder: (BuildContext contex2) => AlertDialog(
          title: receivedNotification.title != null
              ? Text(receivedNotification.title)
              : null,
          content: receivedNotification.body != null
              ? Text(receivedNotification.body)
              : null,
          actions: [
            FlatButton(
              child: Text('Ok'),
              onPressed: () async {
                Navigator.of(context, rootNavigator: true).pop();
                await Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context2) =>
                        SecondScreen(receivedNotification.payload),
                  ),
                );
              },
            )
          ],
        ),
      );
    });
  }

  void _configureSelectNotificationSubject(BuildContext context) {
    selectNotificationSubject.stream.listen((String payload) async {
      await Navigator.push(
        context,
        MaterialPageRoute(builder: (context2) => SecondScreen(payload)),
      );
    });
  }

  NotificationAppLaunchDetails notificationAppLaunchDetails;
  FirebaseMessaging fcm = FirebaseMessaging();
  StreamSubscription iosSubscription;
  NotificationsHandler();

  initializeFcmNotification(BuildContext context) async {
    _configureDidReceiveLocalNotificationSubject(context);
    _configureSelectNotificationSubject(context);
    fcm.configure(
      onMessage: (Map<String, dynamic> message) async {
        debugPrint("[initializeFcmNotification] onMessage: $message");
        message['data']['callback'] = 'onMessage';
        _showBigTextNotification(message);
      },
      onBackgroundMessage: Platform.isIOS ? null : _myBackgroundMessageHandler,
      onLaunch: (Map<String, dynamic> message) async {
        debugPrint("[initializeFcmNotification] onLaunch: $message");
        await Navigator.push(
          HERE_I_USED_A_STATIC_BUILDCONTEXT_VAR,
          MaterialPageRoute(builder: (context2) => SecondScreen('onLaunch')),
        );
      },
      onResume: (Map<String, dynamic> message) async {
        debugPrint("[initializeFcmNotification] onResume: $message");
        await Navigator.push(
          HERE_I_USED_A_STATIC_BUILDCONTEXT_VAR,
          MaterialPageRoute(builder: (context2) => SecondScreen('onResume')),
        );
      },
    );
    var initializationSettingsAndroid = AndroidInitializationSettings('ic_launcher_foreground');
    // Note: permissions aren't requested here just to demonstrate that can be done later using the `requestPermissions()` method
    // of the `IOSFlutterLocalNotificationsPlugin` class
    var initializationSettingsIOS = IOSInitializationSettings(
        onDidReceiveLocalNotification:
            (int id, String title, String body, String payload) async {
          didReceiveLocalNotificationSubject.add(ReceivedNotification(
              id: id, title: title, body: body, payload: payload));
        });
    var initializationSettings = InitializationSettings(
        initializationSettingsAndroid, initializationSettingsIOS);
    await FlutterLocalNotificationsPlugin().initialize(initializationSettings,
        onSelectNotification: (String payload) async {
      if (payload != null) {
        debugPrint('notification payload: ' + payload);
      }
      selectNotificationSubject.add(payload);
    });

    if (Platform.isIOS) {
      iosSubscription = fcm.onIosSettingsRegistered.listen((data) {
        // save the token  OR subscribe to a topic here
      });

      fcm.requestNotificationPermissions(IosNotificationSettings());
    } else {
      _saveDeviceToken();
    }
  }

  static Future<dynamic> _myBackgroundMessageHandler(Map<String, dynamic> message) async {
    debugPrint("[myBackgroundMessageHandler] onBackgroundMessage: $message");
    message['data']['callback'] = 'onBackgroundMessage';
    _showBigTextNotification(message);
    // Or do other work.
    return Future<void>.value();
  }

  static Future<String> _downloadAndSaveFile(String url, String fileName) async {
    Directory directory = await getTemporaryDirectory();
    var filePath = '${directory.path}/$fileName';
    var response = await get(url);
    var file = File(filePath);
    await file.writeAsBytes(response.bodyBytes);
    return filePath;
  }

  static Future<void> _showBigTextNotification(Map<String, dynamic> message) async {
    var largeIconPath = await _downloadAndSaveFile(
        message['data']['image'], 'largeIcon');
    var bigTextStyleInformation = BigTextStyleInformation(
      '${message['data']['body']}',
      htmlFormatBigText: true,
      contentTitle: '${message['data']['title']}',
      htmlFormatContentTitle: true,
      //summaryText: '$summary',
    );
    var androidPlatformChannelSpecifics = AndroidNotificationDetails(
        '0',
        '${message['data']['title']}',
        '${message['data']['body']}',
        enableLights: true,
        color: Color(int.parse(message['data']['mainColor'], radix: 16) + 0xFF000000),
        largeIcon: FilePathAndroidBitmap(largeIconPath),
        ledOnMs: 1000,
        ledOffMs: 500,
        importance: Importance.High,
        priority: Priority.High,
        ledColor: Color(int.parse(message['data']['secondaryColor'], radix: 16)),
        ticker: 'ticker',
        styleInformation: bigTextStyleInformation,
    );
    var iOSPlatformChannelSpecifics =
      IOSNotificationDetails(attachments: [IOSNotificationAttachment(largeIconPath)]);
    var platformChannelSpecifics =
        NotificationDetails(androidPlatformChannelSpecifics, iOSPlatformChannelSpecifics);
    await FlutterLocalNotificationsPlugin().show(
        0, '${message['data']['title']}', '${message['data']['body']}', platformChannelSpecifics, payload: message['data']['callback']);
  }

  /// Get the token, save it to the database for current user
  _saveDeviceToken() async {
    debugPrint("[_saveDeviceToken] FCM_TOKEN: ${await fcm.getToken()}");
  }

  Future<void> onDidReceiveLocalNotification(
      int id, String title, String body, String payload) async {
    // display a dialog with the notification details, tap ok to go to another page
  }
}

Application.java

package PACKAGE_NAME;

import io.flutter.app.FlutterApplication;
import io.flutter.plugin.common.PluginRegistry;
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback;
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService;

public class Application extends FlutterApplication implements PluginRegistrantCallback {
  @Override
  public void onCreate() {
    super.onCreate();
    FlutterFirebaseMessagingService.setPluginRegistrant(this);
  }

  @Override
  public void registerWith(PluginRegistry registry) {
    FirebaseCloudMessagingPluginRegistrant.registerWith(registry);
  }
}

FirebaseCloudMessagingPluginRegistrant.java

package PACKAGE_NAME;

import io.flutter.plugin.common.PluginRegistry;
import io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin;
import io.flutter.plugins.pathprovider.PathProviderPlugin;
import com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin;

public final class FirebaseCloudMessagingPluginRegistrant{
  public static void registerWith(PluginRegistry registry) {
    if (alreadyRegisteredWith(registry)) {
      return;
    }
    io.flutter.plugins.pathprovider.PathProviderPlugin.registerWith(registry.registrarFor("io.flutter.plugins.pathprovider.PathProviderPlugin"));
    com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.registerWith(registry.registrarFor("com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin"));
    FirebaseMessagingPlugin.registerWith(registry.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
  }

  private static boolean alreadyRegisteredWith(PluginRegistry registry) {
    final String key = FirebaseCloudMessagingPluginRegistrant.class.getCanonicalName();
    if (registry.hasPlugin(key)) {
      return true;
    }
    registry.registrarFor(key);
    return false;
  }
}

[royibernthal]

Got it. So yeah, you're doing exactly that :) You're calling flutter_local_notifications in firebase_messaging's onBackgroundMessage.
I suppose it wouldn't even work on IOS due to the simple fact that onBackgroundMessage is not supported on IOS. Let's even pretend for a moment that it doesn't have issues on Android.