How can I get a notification from App Store or APNs when my iOS App gets uninstalled?
Also, if I send a push notification for the device where my App is uninstalled, what happens? Will Apple ban for such rogue Push notifications?
There isn't a way that your app will know if it is uninstalled. Also I do not believe there is anyway Apple will tell you if your app is uninstalled.
Apples Push Notification Service's FeedBack Service does provide a way to know if a device cannot receive a notification. However this does not guarantee that the device was uninstalled, only that it, for whatever reason, can not receive push notifications.
If a provider attempts to deliver a push notification to an application, but the application no longer exists on the device, the device reports that fact to Apple Push Notification Service. This situation often happens when the user has uninstalled the application. If a device reports failed-delivery attempts for an application, APNs needs some way to inform the provider so that it can refrain from sending notifications to that device. Doing this reduces unnecessary message overhead and improves overall system performance.
For this purpose Apple Push Notification Service includes a feedback service that APNs continually updates with a per-application list of devices for which there were failed-delivery attempts.
Related
I have a production iOS app that is receiving, in most cases, all the missed push notifications while the device was offline once I connect it again to the Internet. This app uses Firebase Messaging to receive notifications and the default/recommended configuration code in Firebase's docs.
According to Apple, I would only expect only the last notification to arrive:
Quality of Service, Store-and-Forward, and Coalesced Notifications
Apple Push Notification service includes a Quality of Service (QoS)
component that performs a store-and-forward function. If APNs attempts
to deliver a notification and the destination device is offline, APNs
stores the notification for a limited period of time and delivers it
when the device becomes available again. This component stores only
the most recent notification per device and per app. If a device is
offline, sending a notification request targeting that device causes
the previous request to be discarded. If a device remains offline for
a long time, all its stored notifications in APNs are discarded.
source: apple push notifications documentation
Is Firebase doing something to ensure notifications delivery? I couldn't find any clear doc about this in the case of iOS.
On the other hand, I am working on a completely new version that uses the same Firebase Instance and client configuration, but this time I only receive the last notification no matter what. This new version is not yet released, so I'm testing it in a debug configuration (the production one is release config).
Not sure what is happening here; it's pretty confusing since the implementations are near identical. Has APNS/Firebase any policy regarding the release config and the QoS? I couldn't find anything related to that...
Thank you in advance!
Push notification has some drawback eg:
1. It doesn't revert if its delivered or not
2. If device was off the push notification arrives in bunch. (I don't need the old push notifications if device was off)
For the purposes of displaying messages to users who do not currently have your app open, there is no alternative to Push Notifications.
However, each of the drawbacks you mention does have a solution.
Determining delivery status
There are 2 possible reasons a notification will not be immediately delivered.
The device has uninstalled your app
If the device has uninstalled your app or opted-out of notifications, Apple will return the failed recipient device token through their Feedback Service protocol. In the newest HTTP/2 version of APNS, the failed recipient token will be returned as a response to your HTTP/2 connection.
The device is turned off or does not have a network connection.
Apple will attempt to deliver your most recent notification to the device when the device comes back online. If determining delivery status is essential to you, then you can supply the Content-Available flag and have your application report any successful deliveries of notifications.
Managing notifications when devices are turned off
By default, Apple will deliver only the one most recent notification per application when a device is turned on. This prevents the possibility of a user receiving a deluge of notifications from any single app when they turn on their device.
You can also prevent Apple from delivering old notifications by setting a TTL value. If the TTL expires before Apple is able to successfully send the notification to a device, the notification will be discarded.
How to avoid sending push notification to iOS app that is uninstalled.
Is there any way that we can catch application uninstallation event and call our server to stop sending notification.
What happens to the notification that is sent to device after the app is uninstalled.
Will old and new notification be available in the notification center even after the app is uninstalled.
Please explain.
The APNS Feedback Service exists for this purpose. When you connect to this service, you receive device tokens of devices that uninstalled your application, and you should stop sending push notifications to such device tokens.
When you send a notification to a device that uninstalled the app, Apple logs the device token and will send it to you the next time you contact the Feedback Service.
When you call the APNS service ,you will receive uninstalled app's device tokens.
After that checking those device token, you should stop sending push notifications to those device tokens.
Hope this help.
The documentation specifically states that the feedback service will report devices where the app has been uninstalled and won't report devices if the push merely expired.
My question is, will it report devices that have the app installed but the app called unregisterForRemoteNotifications (e.g. the user "signed out" of the app)?
Documentation:
APNs has a feedback service that maintains a per-application list of devices for which there were failed-delivery attempts (that is, APNs was unable to deliver a push notification to an application on a device). Periodically, the provider should connect with the feedback service to see what devices have persistent failures so that it can refrain from sending push notifications to them.
Source: https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Introduction.html#//apple_ref/doc/uid/TP40008194-CH1-SW14
The Apple Push Notification Service includes a feedback service to give you information about failed push notifications. When a push notification cannot be delivered because the intended app does not exist on the device, the feedback service adds that device’s token to its list. Push notifications that expire before being delivered are not considered a failed delivery and don’t impact the feedback service.
Source: https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/CommunicatingWIthAPS.html#//apple_ref/doc/uid/TP40008194-CH101-SW3
My answer is YES, APNS does have this service in place along with its feedback service, mainly because the server triggering the push service will have to be notified back to stop sending push notification to the devices which have manually opted out of push notification service.
And since there is no way this information can reach back to the server directly except through APNS, APNS manages to hold this information to provide it back to the server.
Our app uses APNS to receive Push Notifications. However, our client claims that some of their devices were not receiving notifications and argues to they 'must' make sure the notifications to be delivered 100%. But I have read somewhere that APNS is not 100% reliable and there should be cases which the notifications are not delivered.
I'm currently panic at how we could make sure APNS to received anytime. I have read that a case which may APNS not delivered (device may offline). But our test showing that even the device is online (Wifi or 3G), sometimes APNS were not delivered.
Is there any specific case which may APNS will not delivered? Or is there anything we (developers) can do with codes to make sure to receive all notifications? What I have done in the code is just registering the app to remote notification and write didRegisterForRemoteNotificationsWithDeviceToken, then throw the device token to our server.
Any help would be appreciated, for our client almost kill us if ALL of their devices not receiving APNS!
APNS is based on Apple Servers, and Apple doesn't give any guarantee on successful message delivery.
If the app is open (i.e. the user is using the app) while the notification arrives, iOS doesn't show a notification message, you need to handle it.
Notification shows up only when the app is backgrounded or killed.
Also implement feedback service on your server side; will help you get rid of old unwanted tokens (users who deleted the app or disabled notifications through settings).
Don't send too many notifications to a device within a short span of time, because APNS caches only 1 message/device (if the device is offline). So it can deliver the message when the device comes online. Am not sure how long the message is cached though.
Or just implement Pusher... http://pusher.com
We're facing the same problem. As everybody said, APNS is a best effort service so you can't be sure every notification will be delivered, but what you can do is to be sure of which ones have been received. This is what we're about to do. We register in our backend each notification que ship and the mobile app reports back each notification it receives. Then we set a maximum time of waiting for a notification to be received, if we don't receive the report back we try again.
I hope it might be helpful to someone (even 2 years later)
It says it quite clearly in the Apple Docs that it is not 100% gauranteed and nor should it be used as so. Its sent with "best effort".
As per Apple's guidelines, APNS is not 100% reliable service which means your app may not get push notifications from Apple servers due to some of the following reasons:
Device is offline
Your app is in the foreground state, you need to manage the push notification.
Note: Apple rejects apps which make compulsion to use notification services. (I have faced it in one of my App)
For more information, you can look into this answer
https://stackoverflow.com/a/25830955/3278326