[firebase_messaging] Disable interception of notification to allow for local notification generation

[Minituff]

Background

I am trying to create a chat app which delivers reliable notifications that includes action buttons such as Mark as Read and Reply which creates an input field.

Unfortunately the firebase_messaging plugin does not support advanced options like Action/Input buttons. So, to do this in Flutter, I am using a great package called AwesomeNotifications which allows for all these advanced features. For anyone unfamiliar, it is like a more advanced version of the Local Notifications plugin.
Using this plugin, I am able to handle the FirebaseMessaging.onBackgroundMessage(_fcmBackgroundHandler); callback from firebase_messaging and generate the notification with all the properties and actions that I like.

The Problem

If the notification includes the notification property then firebase_messaging will automatically display the notification AND AwesomeNotifications will then display its notification--resulting in duplicate notifications.
However, removing the notification property turns it into a data-only notification which, according to the FlutterFire docs are low-priority

As mentioned above, data only messages are classed as "low priority". Devices can throttle and ignore these messages if your application is in the background, terminated, or a variety of other conditions such as low battery or currently high CPU usage.

You should not rely on data only messages to be delivered, they should only be used to support your applications non-critical functionality, e.g. pre-fetching data so the next time the user opens your app the data is ready to be displayed and if the message never gets delivered then your app still functions and fetches data on open.

To help improve delivery, you can bump the priority of messages. Note; this does still not guarantee delivery.

I have also tested this with my own IOS and Android devices and I would not receive data-only messages unless the app was in the foreground or the last used app on IOS. Notifications would not come through if I was using another app, or it was swiped away from recents.

For a chat application, getting reliable messages is a priority and therefore I need to use the notification property to ensure delivery of my notifications. The issues:

1. I cannot use a plugin like AwesomeNotifications or Local Notifications to create advanced functioning notifications because it will create duplicate notifications as long as the notification property is set. However, the notification property is required for reliable notifications.
2. The firebase_messaging plugin does not support advanced features such as Action/Input buttons.

A greater explanation of (number 1):
firebase_messaging automatically intercepts notifications and displays them and I don't think there is a way to disable that. Per the docs below:

Messages can be handled via the onBackgroundMessage handler. When received, an isolate is spawned (Android only, iOS/macOS does not require a separate isolate) allowing you to handle messages even when your application is not running.
and further
If your message is a notification one (includes a notification property), the Firebase SDKs will intercept this and display a visible notification to your users (assuming you have requested permission & the user has notifications enabled). Once displayed, the background handler will be executed (if provided).

The Feature Request

I would like to be able to disable the firebase_messaging automatic notification display while still having the onBackgroundMessage callback fire. This way I can send reliable notifications (with the notification property) and have them be displayed by the more advanced flutter tools.

If this is not possible, then I would love to see ActionButtons and Input fields come to the firebase_messaging plugin.

Additional Infromation

I created another issue here https://github.com/rafaelsetragni/awesome_notifications/issues/165

Below are the plugin versions I am using at the time of writing this

  firebase_core: ^1.1.1
  firebase_messaging: ^9.1.4

[briankariuki]

I second you on this. We should have a way to prevent the default notification if we'd like to handle some logic onBackgroundMessage() then show the notification.

[scalz]

Hello,
Same here, I'm using awesome_notifications, but this is the same with local_notifications package, this would be awesome if this would be doable (just have an option to not show the fcm notification) 🙏

[briankariuki]

A solution to this would be to implement our own onMessage() handler which would allow getting payload from data field and show on the notification. A few guides and leads can be found on this question on stackoverflow

https://stackoverflow.com/questions/37711082/how-to-handle-notification-when-app-in-background-in-firebase

[briankariuki]

This means we do not require firebase_messaging package

[scalz]

Interesting. Well, I hope there is a solution for this, by keeping firebase_messaging, this would be sexy.
I wonder how people handle this case (I've no idea how this handled in others frameworks).
Still, firebase_messaging got lot of great improvements last months, so I'm crossing fingers, and will follow this with interest for sure :)

Thanks Team for all your work you're providing to the community, this is really neat

[mutasimbillah]

any update to this problem ?

[rulefahd]

Any update!!?

[alsoLut]

one year later, the problem is still unresolved.

[SMKH-PRO]

2 more years later still unresolved

[STRATZ-Ken]

Any word on this?

[Minituff]

It looks like the flutter team has decided this will never be implemented: #7874 (comment) ☹️

[briankariuki]

Its possible to handle the fcm message yourself.

//listen to the onMessage stream
FirebaseMessaging.onMessage.listen((RemoteMessage message) async {
     final data = message.data; 

     FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();

      //add your configs to the notifications plugin, here i'm using flutter_local_notifications.
      //then show your notification

    flutterLocalNotificationsPlugin.show(
        data['payload']['id],
        data["title"],
        data["body"],
        NotificationDetails(),
        payload: data['payload']
    )
})

one thing to note is that for the above to work you should send a data only message from your firebase-admin sdk, with the contents of your message as the payload

[FDuhen]

The onMessage method is triggered when the app is in Foreground : it doesn't really fix the original problem since the notifications are not displaying in this case

[yuwankmr]

Thanks It works!

[mutasimbillah]

I have solved this issue by updating packages to :
firebase_core: ^1.19.2
firebase_messaging: ^12.0.0
flutter_local_notifications: ^9.7.0

And add Android Notification Default Channel in AndroidManifest.xml

        android:name="com.google.firebase.messaging.default_notification_channel_id"
        android:value="notification_id"

For More check :
https://github.com/mutasimbillah/Flutter-Push-Notification-with-Custom-Sound-Tutorial

I will update this repository, with proper documentation in near future. Hope it will help some one...

[rulefahd]

What about ios?

[bhanubbs]

ios don't need an advance level of implementation!
because you thread them!

[iosephmagno]

@Minituff I dont think you can use "notification" if you are coding a chat application. Because notifications will display before you have time to decrypt your messages. In case of a chat app, you should use silent (data-only) notification only. This way you can get the payload, decrypt it and use flutter local notification or awesome notification to display a badge.

[rulefahd]

@Minituff I dont think you can use "notification" if you are coding a chat application. Because notifications will display before you have time to decrypt your messages. In case of a chat app, you should use silent (data-only) notification only. This way you can get the payload, decrypt it and use flutter local notification or awesome notification to display a badge.

What about on termination state, data only is not guaranteed to be delivered

[iosephmagno]

Use a non disturbing “notification”

[iosephmagno]

@Minituff added this #7874 (comment)

Indeed there would be this option but firebase team should do their part.

[iosephmagno]

Hello guys, just added feature request #9317

[abhay-s-rawat]

If there is notification json property in the notifications sent from fcm then default fcm notification will show up.
I sent below object via postman, you can test it as well.

{
 "to" : "fcm token id",
 "notification" : { // remove this part to let it handle yourself.
     "body" : "Body of Your Notification 2", 
     "title": "Title of Your Notification 2"
 },
 "data" : {
     "body" : "Body of Your Notification in Data 2",
     "title": "Title of Your Notification in Title 2",
     "key_1" : "Value for key_3",
     "key_2" : "Value for key_4"
 }
}

[Minituff]

@abhay-s-rawat This was mentioned in my original post. If you remove the notification section then the message becomes data-only. A data-only message is considered low priority and you cannot count on its delivery. Check out the docs here.

[wiztensai]

any update?

[akaomarfahim]

firebase_core: ^2.4.0
firebase_messaging: ^14.2.0

I'm using this, strill firebase generates a notification by default.
any update on that.

Though, I can control custom notification with #flutter_local_notifications: ^12.0.4
but, it doesn't route to other specific page from #terminated_state.

[briankariuki]

Remove the notification field from your fcm payload

[phamquoctrongnta]

This problem still occurs in 2023.

[sammrafi]

After a long time, I can able to solve this problem. You just need to remove the notification data from your send message payload and handle everything with data after that you are able to use the custom notification plugin and the notification will only show once.

Previous Payload
const message = { token: deviceToken, notification: { title: 'title', body: 'body', }, data: { key:value } };

Changed Payload
const message = { token: deviceToken, data: { key:value } };

[akshaybengani]

A data-only message is considered low priority and you cannot count on its delivery.
Check this
https://firebase.flutter.dev/docs/messaging/usage/#low-priority-messages

[afaqbhatti1]

With this solution if we terminate the app and then open the app the notification is not shown in any case.

[Muhammad-Ullah]

Any update on this? Removing notification data is not the solution.

[Syed-Waleed-Shah]

Hello Friends! I figured out the solution at last!

If you are using flutter_local_notifications / awesome_notifications or any other custom notifications solution, then you may came to the issue of automatically generated notification by the OS along with your custom notification when the app is in background or is terminated.
Lets solve this problem:
The solution is really simple, just pass null in both title and body parameters of notification object in the payload. And if you still want the title and body then just pass both of them in the data object and extract both from data object. I am writing example payload below:

{
 "to" : "/topics/testing",
"notification" : {
    "body" : null,
    "title": null
},
"data": {
  "title": "This is title",
  "body": "This is body"
}
}

If you send this payload from backend then the automatically generated notification will never displayed & you will only see your custom notification with HIGH PRIORITY!

Note: I only testing it on Android device because I donot have MAC :) but anyone of you please test it in IOS as well and tell us the behaviour in this thread. Help the community!

[Syed-Waleed-Shah]

@Minituff @scalz @alsoLut @wiztensai @akshaybengani @Muhammad-Ullah

[akshaycashee]

Android
In Android Data only messages have normal priority compared to other notifications as such if your app stays in background for longer or goes in sleep or app is killed then the notification wont show check this article for more information
https://firebase.google.com/docs/cloud-messaging/android/message-priority

IOS
In IOS data only messages are treated like background notifications, these are at lowest priority and most of the time they don't get delivered, I tested this so many times 50% is what I achieved as success rate in IOS even when app is not killed, or stayed in background for longer.
To make sure Notifications get delivered you need to pass at least title in the notification payload
https://stackoverflow.com/a/63354561/5867698

[Syed-Waleed-Shah]

But in this case the notification is not data only. We have provided the notification object in payload. We just passed null in title and body, therefore our OS will not treat it as data only notification. @akshaybengani

[akshaybengani]

Well it doesn't work like that, FCM ignore null and empty values, it's part of the json parser only. If you want to check print the notification payload output in your onBackgroundMessage or onMessage callbacks You will get null response for the notification key. Still if you are confident with this, make sure to test this properly with a release build with different edge cases like, app minimize, killed, force stop, battery saver mode Also print the notification priority payload you will get the idea what priority FCM sets for data only notification.

…

On Mon, 25 Sept, 2023, 11:37 pm Syed-Waleed-Shah, ***@***.***> wrote: But in this case the notification is not data only. We have provided the notification object in payload. We just passed null in title and body, therefore our OS will not treat it as data only notification. @akshaybengani <https://github.com/akshaybengani> — Reply to this email directly, view it on GitHub <#6113 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFMQ72GQJYWJZHLJ3PWL7P3X4HB4HANCNFSM44XMDQWQ> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[Syed-Waleed-Shah]

I have tested it in following scenarios (Working perfectly fine):

• Foreground
• Background
• App Terminated
• Mobile powered off then powered on (or Restarted)
• App force stop

Not tested in following cases:

• Power saving mode.

Note: Did'not tested on IOS.

[akshaybengani]

Sounds great, will test it again with the updated packages on both IOS and Android.

Please let us know if there any specific changes you have done during the FCM integration

Thanks for the finding a solution

[erdnj]

Have you tested or found another solution?

[chihong98]

I tested it myself on both IOS and Android. Passing null to the title and body is not a solution for me, as it would still show a notification but with empty title and body for android phone.

However, removing the notification parameter from the payload solves the issue, and it works in the foreground, background, and terminated states for both IOS and android phone.

I also tested it on iOS power-saving mode following @Syed-Waleed-Shah test scenario, and the notification shows up very randomly. In my test scenario, continuously sending 10 notifications at a time, only the first 3-4 notifications will be received, and the subsequent ones will not. However if not on power-saving mode, all 10 will be received.

Below is my sample payload:
{ "to" : "/topics/testing", "data": { "title": "This is title", "body": "This is body" } }

[Attia-Fouad]

Did you find a solution to this problem?

[altafkhan8719]

any update on this, i am also facing same issue from the past 3 days

[shanmukhaaditya10]

any leads ?

[1991vicky1991]

any leads??

[hippedorange22]

As of writing this reply, with firebase_messaging: ^14.7.17 , @Syed-Waleed-Shah's workaround, passing null as value to title and body keys in notification payload does indeed work, i have flutter_local_notifications setup in my project to handle all notifications with customizations and this workaround does indeed send the notification but isn't intepreted by the firebase_messaging sdk, but populated data object triggeres local notification handling. Tested on both Android and iOS, and works in all states, Foreground, Background and especially Terminated. Did not test in power saving mode.

[akshaybengani]

I work in a bank and as per their new data processing policy, they said you can only send encrypted data in Push Notifications with a custom encryption key, therefore in order to decrypt it at client device I definitely need to show local notifications.
It's so terrible that we don't have any solution for this and we have to remove firebase messaging entirely

[dishankjindal1]

Sad story @akshaybengani. Seems like i am going to do the same. What alternative did you end up using?

[akshaybengani]

SMS for important alerts, and in app messaging through web sockets when app is foreground

[rinkuanuragkumar]

Any update? I am also facing the same issue from past 7 days.

[ChauCM]

data only notification doesn't work for IOS anymore

[vgavrilovikj]

So it is no longer possible to send data-only notifications?? How do other popular apps handle this..? (Insta, X, Messenger, Snapchat,..)

[akshaybengani]

They have a native app with Background services that use polling servers or web sockets to check for any new messages
Google's Firebase Cloud Messaging for Android, or Apple's Push Notification Service for iOS.
so I think we should look for a native bridge solution to see how it works

[agent515]

Same issue. What notification solution should a E2EE chat app implement where message needs to be decrypted before showing in the notification banner? Background Service was my guess but again it poses unpredictability on iOS.