[Question] Push notification messages are not displayed in the closed/background app on launch

[equizo]

[REQUIRED] Please fill in the following fields:

• Unity editor version: 2020.3.10
• Firebase Unity SDK version: 8.1.0
• Source you installed the SDK: unitypackage
• Problematic Firebase Component: Messaging
• Other Firebase Components in use: Analytics, Deepliinks, Crashlytics,
• Additional SDKs you are using: Facebook, IronSource
• Platform you are using the Unity editor on Windows
• Platform you are targeting: Android
• Scripting Runtime: IL2CPP

[REQUIRED] Please describe the question here:

Push notification messages are not received in the app if the app is either closed or is in the background. The foreground app receives messages OK.

queued message 0:1628115171791201%bfe3fe3bbfe3fe3b
Firebase.AppUtilPINVOKE:PollCallbacks()
Firebase.AppUtil:PollCallbacks()
Firebase.Platform.FirebaseHandler:Update()

and

2021-08-10 00:14:38.207 23350-23465/com.threed_view.FluentWorldsDev E/Unity: Couldn't parse the message: Object reference not set to an instance of an object.
    VIEW.VCT.Common.VCTLog:Error(String, String)
    VIEW.VCT.Common.VCTLog:CatchLogs(String, String, LogType)
    UnityEngine.LogCallback:Invoke(String, String, LogType)
    VIEW.VCT.Common.MessagingService:OnMessageReceived(Object, MessageReceivedEventArgs)
    System.EventHandler`1:Invoke(Object, TEventArgs)
    Firebase.Messaging.<MessageReceivedDelegateMethod>c__AnonStorey0:<>m__0()
    System.Func`1:Invoke()
    Firebase.ExceptionAggregator:Wrap(Func`1, T)
    Firebase.AppUtilPINVOKE:PollCallbacks()
    Firebase.AppUtil:PollCallbacks()
    Firebase.Platform.FirebaseHandler:Update()

2021-08-10 00:01:16.109 20990-21989/com.threed_view.FluentWorldsDev W/FirebaseMessaging: Missing Default Notification Channel metadata in AndroidManifest. Default value will be used.

So I guess I somehow missing on queued message handling when app is launched?

[vimanyu]

Hi,
Thank you for creating this issue. It would help to have some more information to be able to debug this more efficiently.
Could you try reproducing this issue in our quickstart-unity test app?

I did a quick test on our app and it worked as expected. Here are the steps I performed,

1. Clone our github repo locally and navigate to messaging/testapp
2. Place a valid "google-services.json" for your project into Assets/
3. Open in Unity (I used Unity 2020.1.7f1) and change Build settings to Android and update the bundle identifier in "Player Settings -> Android -> Other settings -> Identification -> Package name" to something that corresponds with your google-services.json.
4. Build and Run (I am using a Pixel 5 for my test)
5. Sending message from Firebase console with some data in it and here is the behavior on the app,

State	Result
App in foreground	Message received and you can see the notification details (title, body) along with data
App in background	Clicking notification opens the app and shows the data

Let me know if you need more details but I am curious if you are seeing similar behavior on your end.

[equizo]

Hi there. The notification is received but I need to verify this event by sending event from unity. OnMessageReceived is not triggered of the app was killed. ср, 11 авг. 2021 г., 11:22 PM Vimanyu Jain ***@***.***>:

…

Hi, Thank you for creating this issue. It would help to have some more information to be able to debug this more efficiently. Could you try reproducing this issue in our quickstart-unity test app? I did a quick test on our app and it worked as expected. Here are the steps I performed, 1. Clone our github repo locally and navigate to messaging/testapp 2. Place a valid "google-services.json" for your project into Assets/ 3. Open in Unity (I used Unity 2020.1.7f1) and change Build settings to Android and update the bundle identifier in "Player Settings -> Android -> Other settings -> Identification -> Package name" to something that corresponds with your google-services.json. 4. Build and Run (I am using a Pixel 5 for my test) 5. Sending message from Firebase console with some data in it and here is the behavior on the app, | State | Result | | ---- | ----- | | App in foreground | Message received and you can see the notification details (title, body) along with data | | App in background | Clicking notification opens the app and shows the data| Let me know if you need more details but I am curious if you are seeing similar behavior on your end. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1111 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABVBQYFXE5SPAROKOSN5XSTT4LLZPANCNFSM5B266WBQ> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&utm_campaign=notification-email> .

[vimanyu]

Hi @equizo,
Thanks for responding but I am not sure if I understand the behavior of the app on your end. Is the OnMessageReceived not triggering only when the app was killed and a notification was received in the background? (I tried both cases, kill app and send background notification, background app and send background notification, and both of them worked as per the table above).
Does the notification work when you send it while the app is in background (not killed)?
Please note that you will only see "data" fields from background notifications.

Which event are you sending from Unity?

[equizo]

@vimanyu
That's correct. When the app is in foreground/background - no issues, I can see OnMessageReceived triggered in Unity.
Only when the app is killed I don't see any triggering in the app. Notifications are received in all cases, but there is nowhere I can track this in the app. I need to know if the app was open from notification, for that, I send a firebase analytics event in OnMessageReceived, and the Debug.Log calls to track locally in the LogCat once I tap the notification.
The builds are done in Android Studio (Unity -> export Android project).

Could you tell how do you get if "data" was received on the device? Also, do you send the notifications from the FCM console?

[cynthiajoan]

Hi @equizo,

From what I know, here's a quote of this issue:

The Android framework advises that apps that have been stopped (i.e. killed/force-stopped from Settings) should not be started without explicit user interaction. FCM follows this recommendation, and thus does not deliver messages to stopped apps. Here are some documentation that discuss this topic:

Life of a message from FCM to the device Using Firebase Cloud
Messaging with Android O

So this is an expected behavior that app's killed would not receive FCM notification.

[equizo]

hi @cynthiajoan
Excuse me I did not mean settings kill/force stop. But just close the app, meaning it is no longer minimized/(background?) but just is in the "cold" state, not being recently launched. Is this is what it means? The notifications are still received by the device. But there is no way to trigger OnMessageReceived or any other way of verifying if the app was open from the notification.