Ckfetchnotificationchangesoperation Sometimes Does Not Return Update, Delete Notifications

CKSubscription of type CKSubscriptionOptionsFiresOnRecordUpdate doesn't work

Its a known bug that update notifications are not working.

[CKFetchNotificationChangesOperation sometimes does not return UPDATE, DELETE notifications
[CloudKit push notifications on record update stopped working
[https://forums.developer.apple.com/thread/7288][3]

Alternatives to UPDATE notification that does not work

I have used a similar strategy. There are some drawbacks:

• more data (storage and transfer) usage
• limited subscription possibilities or you have to duplicate even more data.
• extra code in your app that you actually don't want to be there.

The only good solution to this problem is:

• Apple should fix it...

CloudKit: delete CKSubscription is not working

Ok, this isn't the definitive answer, but need to put some code down and the comments are too short. What does it all mean; the first method fetches any outstanding notifications, the second makes sure you the same page as regarding their attention.

You need to make sure you got something like place before deleting the subscriptions ideally.

Disclaimer this is demo code; and I haven't tested it extensively. But it should work.

func fetchSubsInPlace() {
    let container = CKContainer(identifier: "iCloud.ch")
    let publicDB = container.publicCloudDatabase

    publicDB.fetchAllSubscriptionsWithCompletionHandler({subscriptions, error in
        for subscriptionObject in subscriptions! {
            let subscription: CKSubscription = subscriptionObject as CKSubscription
            print("subscription \(subscription)")
        }
    })
}

func fetchNotificationChanges() {
    let operation = CKFetchNotificationChangesOperation(previousServerChangeToken: nil)

    var notificationIDsToMarkRead = [CKNotificationID]()

    operation.notificationChangedBlock = { (notification: CKNotification) -> Void in
        // Process each notification received
        if notification.notificationType == .Query {
            let queryNotification = notification as! CKQueryNotification
            let reason = queryNotification.queryNotificationReason
            let recordID = queryNotification.recordID

            print("reason \(reason)")
            print("recordID \(recordID)")
            // Do your process here depending on the reason of the change

            // Add the notification id to the array of processed notifications to mark them as read
            notificationIDsToMarkRead.append(queryNotification.notificationID!)
        }
    }

    operation.fetchNotificationChangesCompletionBlock = { (serverChangeToken: CKServerChangeToken?, operationError: NSError?) -> Void in
        guard operationError == nil else {
            // Handle the error here
            return
        }

        // Mark the notifications as read to avoid processing them again
        let markOperation = CKMarkNotificationsReadOperation(notificationIDsToMarkRead: notificationIDsToMarkRead)
        markOperation.markNotificationsReadCompletionBlock = { (notificationIDsMarkedRead: [CKNotificationID]?, operationError: NSError?) -> Void in
            guard operationError == nil else {
                // Handle the error here
                return
            }
        }

        let operationQueue = NSOperationQueue()
        operationQueue.addOperation(markOperation)
    }

    let operationQueue = NSOperationQueue()
    operationQueue.addOperation(operation)
}

}

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