remoteNotificationReceivedHandler not setup, displaying normal OneSignal notification flutter - flutter

Question

handle background notification in onesingnal flutter. i want to print my notification in console when app is in background. for foreground notification i used setNotificationWillShowInForegroundHandler. now for handling background notification flutter.

Answer 1

when the app is terminated you can’t print anything but if the app is running in the background you can print notifications or notification additional data like this.
add NotificationServiceExtension.jave file in android > app > src > main > kotlin > next to mainActivity
add the following code:
package your bundle_id;
import android.content.Context;
import android.util.Log;
import org.json.JSONObject;
import com.onesignal.OSNotification;
import com.onesignal.OSMutableNotification;
import com.onesignal.OSNotificationReceivedEvent;
import com.onesignal.OneSignal.OSRemoteNotificationReceivedHandler;
#SuppressWarnings("unused")
public class NotificationServiceExtension implements
OSRemoteNotificationReceivedHandler {
#Override
public void remoteNotificationReceived(Context context, OSNotificationReceivedEvent notificationReceivedEvent) {
OSNotification notification = notificationReceivedEvent.getNotification();
Log.i("OneSignalExample", "Notification Data: " + notification);
// Example of modifying the notification's accent color
OSMutableNotification mutableNotification = notification.mutableCopy();
mutableNotification.setExtender(builder -> {
// Sets the accent color to Green on Android 5+ devices.
//Force remove push from Notification Center after 30 seconds
builder.setTimeoutAfter(30000);
return builder;
});
JSONObject data = notification.getAdditionalData();
//log.i will print data in body of notification
Log.i("OneSignalExample", "Received Notification Data: " + data);
// If complete isn't call within a time period of 25 seconds,
OneSignal internal logic will show the original notification
// To omit displaying a notification, pass `null` to complete()
notificationReceivedEvent.complete(mutableNotification);
}
}
don't forget to add these tags just below application tag in manifest android
<meta-data android:name="com.onesignal.NotificationServiceExtension"
android:value="your_bundle_id.NotificationServiceExtension" />