What happened?

I’m trying to implement Android INotificationServiceExtension in a .NET MAUI application using OneSignalSDK.DotNet 5.0.2
I have followed the instructions from https://documentation.onesignal.com/docs/service-extensions#android-notification-service-extension

The DotNet SDK does not wrap the Android code, so I must implement the interface from the Android binding project.

public class NotificationServiceExtension : Java.Lang.Object, Com.OneSignal.Android.Notifications.INotificationServiceExtension
{
    public void OnNotificationReceived(INotificationReceivedEvent e)
    {
        Console.WriteLine($"{LogHelper.Tag} OnNotificationReceived START");

        // Customizing the notification alternative one:
        e.PreventDefault();
        var notification = OneSignalSDK.DotNet.Android.Utilities.FromNativeConversion.ToNotification(e.Notification);
        Console.WriteLine($"{LogHelper.Tag} Title: {notification.Title} Body: {notification.Body}");
        // TODO: Create a local notification with the data from the notification.
		
        // Customizing the notification alternative two:
        // IMutableNotification is an Empty interface, can't modify the notification.
        IMutableNotification mutableNotification = e.Notification;

        Console.WriteLine($"{LogHelper.Tag} OnNotificationReceived END");
    }
}

I have successfully received the event in both foreground and background and created my own push message using Notification.AdditionalData.

I call e.PreventDefault() to suppress the push message created by the OneSignalSDK, however after approximately 30 seconds the following log message is written and there is no "Confirmed" callback to OneSignal.

remoteNotificationReceived timed out, continuing with wantsToDisplay=false.
kotlinx.coroutines.TimeoutCancellationException: Timed out waiting for 30000 ms
   at  kotlinx.coroutines.TimeoutKt.TimeoutCancellationException(Timeout.kt:191)
   at kotlinx.coroutines.TimeoutCoroutine.run(Timeout.kt:159)
   at kotlinx.coroutines.EventLoopImplBase$DelayedRunnableTask.run(EventLoop.common.kt:501)
   at kotlinx.coroutines.EventLoopImplBase.processNextEvent(EventLoop.common.kt:280)
   at kotlinx.coroutines.DefaultExecutor.run(DefaultExecutor.kt:108)
   at java.lang.Thread.run(Thread.java:1012)

However there is a greater problem with calling e.PreventDefault(), push notifications are sent multiple times to INotificationServiceExtension.OnNotificationReceived().

onesignal_logcat_duplicate_notification.csv

MauiApp1.zip

Steps to reproduce?

One way to reproduce this is using the attached sample app.

After setting `OneSignalAppId` in `App.xaml.cs`, start the application, allow push, send a push from OneSignal and see that _Title_ and _Message_ are logged.

Restart the application, and the same _Title_ and _Message_ are logged again. See the attached log file `onesignal_logcat_duplicate_notification.csv`.

When running the application without calling `e.PreventDefault()` push notifications are delivered once to `INotificationServiceExtension.OnNotificationReceived()`.


logcat filter: (OneSignal | ************************************) -message:open_from_bundles

What did you expect to happen?

Alternative one e.PreventDefault()

Q1. How can I use e.PreventDefault() and set the event as successfully completed so that:

• INotificationServiceExtension.OnNotificationReceived() is only called once for each push notification, avoid Restoring notifications. (Critical)
• remoteNotificationReceived timed out exception is not logged. (Optional)
• Confirmed status callback is completed to OneSignal. (Optional)

Q2. Are there any plans to implement INotificationServiceExtension in SDK so that I don’t need to use the Android.Binding project.

Alternative two notification.setExtender(...)

The OneSignal Android SDK has an interface IMutableNotification with a setExtender method, https://documentation.onesignal.com/docs/service-extensions#step-1-create-a-class-for-the-service-extension

notification.setExtender(builder -> builder.setColor(0xFF0000FF));

There is no such method available in the OneSignalSDK.DotNet IMutableNotification interface, the interface is empty.

Q3. How can i modify the notification before it is displayed by the OneSignalSDK.DotNet?

Relevant log output

No response

Code of Conduct

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