FCM data message not coming when app is closed in ios

Question

I have integrated FCM in my flutter project with flutter_local_notification. Everything works as expected in Android. However, ios also works almost except when app is closed from history. When app is cleared from history messages are not triggering. I am using only data message in push notification. Please have a look below:

{
   "to": "/topics/global",
   "priority": "high",
   "content_available": true,
   "data": {
      "title": "Demo Title",
      "message": "Demo Message",
      "payload": "basic"
   }
}

As you can see there is no notification object in the json. This configuration is working fine on Android (foreground & background) and for ios only foreground. However, if i add the notification object in this json surprisingly it works even the app is closed.

But as i need to handle the notification manually that option doesn't fit for my use case. So i researched further and disabled Method Swizzling

FirebaseAppDelegateProxyEnabled

But that didn't help either. Now i'm kinda lost and can't find a way to achieve expected result. My AppDelegate.swift is given below

import UIKit
import Flutter

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
   override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    GeneratedPluginRegistrant.register(with: self)
    if #available(iOS 10.0, *) {
      UNUserNotificationCenter.current().delegate = self as UNUserNotificationCenterDelegate
    }
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

NOTE: The ios app is published in TestFlight and testing on a real device

user_16023905 · Answer

After a long research i couldn't find an absolute fix for this issue. However, i have implemented a workaround for the issue.

I have 3 scenario of sending notification which are

1. Sending notification to specific user
2. Sending notification to all user
3. Sending notification to a topic

When user opens the app i check which platform the user is using. If it's Android then i store the device token as android otherwise ios. At the same time i also register the user to a topic global_android if platform is Android and global_ios if platform is ios.

Now when i send notification from admin panel i match the condition with above 3 scenario. For android i use following json configuration to send notification

{
  "to": "topic || token",
  "priority": "high",
  "content_available": true,
  "data": {
     "title": "Demo Title",
     "message": "Demo Message",
     "payload": "basic"
  }
}

And for ios i use following configuration

{
  "to": "/topics/global",
  "priority": "high",
  "content_available": true,
  "notification": {
     "title": "Demo Title",
     "body": "Demo Message"
  },
  "data":{
      "key1":"value",
      "key2":"value"
  }
}

And now when i receive the notification i check the platform again. If it's Android then i show a custom notification using 'flutter_local_notification' plugin and if it's ios then i do nothing because the notification is shown already by firebase.

This is not an absolute solve but guess what, it's working for me.

user_9405238 · Answer

Same problem with me. It is error from firebase_messaging library. This issue was discussed more than 1 year ago but still no solution. Details see here FCM Notification IOS.

FCM data message not coming when app is closed in ios

2 Answers