PushNotifications totally broken on Android

[frederikbosch]

Bug Report

Plugin(s)

PushNotifications

Capacitor Version

7.0.x

Platform(s)

Android

Current Behavior

• getDeliveredNotifications() throws as the linked PR shows
• pushNotificationActionPerformed event throws as the linked PR shows
• getDeliveredNotifications() notification.id is an int
• removeDeliveredNotifications() does not work when passing a notification from getDeliveredNotifications()
• according to documentation ActionPerformed object has a key .notification that represents the notification as PushNotificationSchema object, which is not the case. The notification object contains the id key merged with the keys from the data object. It does not have title, body and other keys.

[frederikbosch]

So, Android is just handling this all very differently than iOS.

1. There is the Firebase RemoteMessage object containing an id as String. This object is instantiated when the app is in the foreground and pushNotificationReceived is triggered. The RemoteMessage does contain the title and body of the notification.
2. On the other hand, when a new intent is received and it is handled in the handleOnNewIntent, the attached Bundle does contain a key google.message_id. But the bundle does not contain the title and body of the notification.
3. Then we have getDeliveredNotifications(). From the notificationManager we can ask the active notifications and from the returned StatusBarNotification we can get call getNotification(). That notification contains the id of the notification as an integer. It does not contain title and body. Hence, it cannot return notifications as a PushNotificationSchema.

This cannot be fixed without any backward incompatible changes. Since getDeliveredNotifications() is broken anyhow, my suggestion would be to change the returned type of that call. My suggestions to proceed are the following.

1. Change the notifications key in DeliveredNotifications to a new type DeliveredPushNotificationSchema. This type should have a nullable String id key which is only used by iOS. It should have a String deliveryId that contains the same id on iOS and the integer.toString() id from Android's Notification object. Also, title and body should be nullable strings since those keys are missing on Android.
2. Add documentation advice to include title and body in the data of a notification if you need this in the app, since only data is available in all calls.
3. Merge PR fix(android): notification Bundles with non-string values #2445 to prevent exceptions by Android.