I am using iOS push notifications. In Android you can set up to 4 notification keys and then using these keys you can have notifications replace prior notifications if they have not yet been read/seen by the user.
Do iOS push notifications also allow you to selectively replace prior notifications? (E.g. using a common notification key) or do they always "rack up" and cannot be replaced.
Link: Local and Push Notification Programming Guide:
Quality of Service
Apple Push Notification service includes a default Quality of Service
(QoS) component that performs a store-and-forward function.
If APNs attempts to deliver a notification but the device is offline,
the notification is stored for a limited period of time, and delivered
to the device when it becomes available.
Only one recent notification for a particular application is stored.
If multiple notifications are sent while the device is offline, each
new notification causes the prior notification to be discarded. This
behavior of keeping only the newest notification is referred to as
coalescing notifications.
If the device remains offline for a long time, any notifications that
were being stored for it are discarded.
There's no such mechanism in place in iOS.
After sending a push notification you have no control over it anymore.
Related
Here's what docs state:
The priority of the notification. Specify one of the following values:
10–Send the push message immediately. Notifications with this priority
must trigger an alert, sound, or badge on the target device. It is an
error to use this priority for a push notification that contains only
the content-available key.
5—Send the push message at a time that takes into account power
considerations for the device. Notifications with this priority might
be grouped and delivered in bursts. They are throttled, and in some
cases are not delivered.
And about VoIP:
Instead of persistent connections, developers should use the PushKit
framework—APIs that allows an app to receive pushes (notifications
when data is available) from a remote server. Whenever a push is
received, the app is called to action. For example, a VoIP app could
display an alert when a call is received, and provide an option to
accept or reject the call. It could even begin taking precursory steps
to initiate the call, in the event the user decides to accept.
Do I understand correctly that apns-priority defines message queuing at APNS side, and VoIP push type defines what happens on the device?
And what do they mean saying
It is an error to use this priority for a push notification that contains only the content-available key.
Will APNS return an error or is it just a bad practice?
P.S. I use AWS SNS for sending notifications and it does not support customisation of apns-priority, but I am curious how it affects the process.
The main difference is that even if your app is closed voip notification can wake your app for kill/suspended state and user notification just shows an alert without waking up your app for more refer.
Apple documentation for pushkit
The main difference is that VoIP notification will launch your app if it's not running or was killed from app switcher and you need to handle the notification in your code, while the normal notification will be shown immediately as local notification and will not start your app.
Is there any way to handle remote notification payloads before they’re delivered and display in notification centre?
With push notifications of default type there is no way to filter out notifications if the app is not in foreground.
The possible solution to this is to use VoIP push notifications in conjunction with PushKit.
VoIP pushes are always waking up the application, however they are not presented to the user and don't modify app badge value, so it's up to the developer to show a local notification upon the received VoIP push and to deal with app badge.
There is a technique with additional silent push that for example Facebook is using, to delete notification on iOS device when the message has been read on desktop web site. It's described here: https://www.pushwoosh.com/docs/deletable-ios-push
I want to send push notification to app users. Users whom online will receive it immediately, right?. But what about users whom offline? Will they get notification after they become online?
Can you tell me more about than push notifications will de delivered?
Are messengers use pushes to send notifications about new messages?
Not possible in offline.
Check it: https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/ApplePushService.html
Apple Push Notification Service includes a default Quality of Service (QoS) component that performs a store-and-forward function. If APNs attempts to deliver a notification but the device is offline, the QoS stores the notification. It retains only one notification per application on a device: the last notification received from a provider for that application. When the offline device later reconnects, the QoS forwards the stored notification to the device. The QoS retains a notification for a limited period before deleting it.
If a device remains offline for a long time, all notifications that were being stored for it are discarded; when the device goes back online, none of the notifications are displayed.
Basically Apple will try to deliver the notification when the device will become online again (in a resonable time frame).
Apple Push Notification service includes a default Quality of Service (QoS) component that performs a store-and-forward function. If APNs attempts to deliver a notification but the destination device is offline, APNs stores the notification for a limited period of time and delivers it to the device when the device becomes available.
From https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/ApplePushService.html#//apple_ref/doc/uid/TP40008194-CH100-SW9
What is the PushKit QoS policy? The policy for the regular push notification is defined as store-and-forward.
Apple Push Notification service includes a default Quality of Service
(QoS) component that performs a store-and-forward function.
If APNs attempts to deliver a notification but the device is offline,
the notification is stored for a limited period of time, and delivered
to the device when it becomes available.
Only one recent notification for a particular app is stored. If
multiple notifications are sent while the device is offline, each new
notification causes the prior notification to be discarded. This
behavior of keeping only the newest notification is referred to as
coalescing notifications.
If the device remains offline for a long time, any notifications that
were being stored for it are discarded.
What about PushKit notification? Is it the same as for regular push notifications?
I performed the following steps to verify the issue myself
Put the device in airplane mode
Sent at least 5 different PushKit notifications
Wait for about 3 minutes
Cancel the airplane mode
Only the last PushKit notification arrived which is compatible with the store-and-forward Apple's policy (which is specifically defined for regular remote push notifications).
The topic I want to discuss may be a duplicate of this question. But still I've a few queries regarding Apple Push Notifications.
I have one app supported on both Android and iOS. The app needs a background service which hits a remote server every minute. The job is simple for Android app but since background tasking is not supported in iOS I need to employ push notifications for iOS app. I am using PushSharp library to deliver push notifications. Apple says that the delivery of push notification is not acknowledged. I cannot afford push notification failure since I need to send a very crucial message through notification. My questions are:
1) What is the failure rate of push notifications?
2) Are push notifications always reliable to send important messages?
3) Assume that the server which is supposed to send push notifications sends a large number of push notifications every minute. What are the chances of push notification failure in such a case?
4) Which circumstances cause push notification delivery to fail?
If you have any useful resources please provide the same. Thanks.
Please find my comments below.Hope this helps.
What is the failure rate of push notifications?
Apple has not disclosed it so far.
Are push notifications always reliable to send important messages?
Delivery of notifications is a “best effort”, not guaranteed. It is not intended to deliver data to your app, only to notify the user that there is new data available.
Please refer - https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/ApplePushService.html
Assume that the server which is supposed to send push notifications sends a large number of push notifications every minute. What are the chances of push notification failure in such a case?
Only one recent notification for a particular application is stored. If multiple notifications are sent while the device is offline, each new notification causes the prior notification to be discarded. This behavior of keeping only the newest notification is referred to as coalescing notifications.
Please refer - https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/ApplePushService.html
Which circumstances cause push notification delivery to fail?
If APNs attempts to deliver a notification but the device is offline, the notification is stored for a limited period of time, and delivered to the device when it becomes available.
Please refer - https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/ApplePushService.html