APNS Modify Notification to be a Silent Notification - ios

I have a weird feature I'm looking to add to iOS and am not sure if it's possible.
I want to send push notifications to all users through a third party and have the client decide whether or not to show it depending on some feature. I was reading that I can modify the notification before it reaches the app and was hoping that I could receive the notification, do some logic and, if the criteria is satisfied, modify the notification to be silent. But I'm not sure if this is possible.
Has anybody been able to do this?

As far as I know, it's not possible to hide a notification after it was sent.
You can modify the payload through a service extension but I'm pretty sure you cannot hide it from the user.
To decide on the client if a notification is visible or not - you'll have to send your notification as silent to begin with and then trigger a local notification.
The problems with that are:
Silent notifications are disabled if the user disabled Background Activity.
Silent notifications have a lower priority and might be throttled after a while.
The purpose of silent pushes is to inform the app of new content to perform a background fetch.
My recommendation is to put whatever logic you want on the server side before sending the notification.

For Android you can decide whether to show the notification or not.
For iOS, you can only modify the way the notification is presented but you cannot stop it from being shown. In order to modify the way the notification is presented to the user on iOS you need to add a Notification Extension Service.

Related

Who handles the notification in iOS? - really React Native

I have a doubt, I've searched and didn't find the answer, I have implemented notification in my app, is it possible to have a cancel notification in the app or it is only a system option?
When the user opens my app on the third screen it asks about sending notifications, but what if the user doesn't want to receive those notifications anymore, does he need to go to iOS settings or can I do this from the app?
Thanks for your time
If you've used react-native-push-notification or #react-native-community/push-notification-ios then there has a way to remove notification from notification center.
you can use this code to remove all natification
PushNotification.removeAllDeliveredNotifications();
Removes the specified notifications from Notification Center
PushNotification.removeDeliveredNotifications(identifiers);
check out official doc for more detail
packages:
https://www.npmjs.com/package/react-native-push-notification
https://www.npmjs.com/package/#react-native-community/push-notification-ios
If you no longer needed to receive notifications in your app, it's better to handle the logic in your backend. When the user denies permission, remove the push token from the server. If you only want to remove certain types of notifications, instead of removing tokens, you can set a flag on backend logic to enable/disable certain notifications.
If you really want to do this on the client-side, you can use data-only notifications of FCM or a similar kind, where you have the control to present notifications as local notifications. Basically, a background listener will be triggered when you receive a data-only notification and OS won't present notification. You need to create a local notification and present it according to the data you receive. Here you can add your logic to filter notifications based on User's choice

How to make a remote notification conditionally displayed?

In our app environment, multiple shifts of employees use the same phone. It is possible for our app to receive notifications intended for a prior user. Our notification extension can determine if the notification is for the current user. We'd like to hide the notification if its not intended for the currently logged in user.
Notification Extensions, (UNNotificationServiceExtension) apparently do not allow the notification to be hidden. It can be modified but will always be presented to the user.
Why?
Is there a way around this?
I've tried sending silent notifications and generating local notifications. It works, but Apple/iOS starts throttling it after a few notifications and it becomes very unreliable.

How can I cancel or stop push notification from a client?

I have a webserver that sent a client a push notification. The client can intercept the push notification with UNNotificationServiceExtension on iOS 10 and change the content. Now I want to cancel a push notification from showing on client side on certain notifications. How do I do that? I tried to do
self.contentHandler(nil);
but it didn't work. How to do it?
It look like it might not be possible, but not sure. From the docs:
You can modify any of the content from the original request. You might
customize the content for the current user or replace it altogether.
You can use this method to download images or movies and add them as
attachments to the content. You may also modify the alert text as long
as you do not remove it. If the content object does not contain any
alert text, the system ignores your modifications and delivers the
original notification content.
https://developer.apple.com/reference/usernotifications/unnotificationserviceextension/1648229-didreceivenotificationrequest?language=objc
Calling the block with nil just displays the original notification?
It's now possible since iOS 13.3. You need to pass an empty UNNotificationContent to contentHandler (not nil) and add the new filtering entitlement.
// Determine whether you should suppress the notification.
let suppress = myShouldSuppressNotification(request: request)
if suppress {
// Don't deliver the notification to the user.
contentHandler(UNNotificationContent())
} else { ///...
Reference : https://developer.apple.com/documentation/bundleresources/entitlements/com_apple_developer_usernotifications_filtering
I think the easiest way would be to send every push notification as a silent notification by default and only show the ones that you want to show. When you get a silent notification in
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any])
You check your notification and determine if it should be displayed to the user. If not, you do nothing with it. If it needs to be shown then create a local notification and display it UILocalNotification (iOS 9 and earlier) or UNNotification (iOS 10).
I should add this has the disadvantage that no notifications will show if the app is not resident in memory (because the app needs to make the silent notification into a local notification), but if you were to take the opposite tact then you have the problem that something might be shown that shouldn't be show.
On iOS 10 and above you can send you a "silent" notification:
Apple doc: configure silent notification
Then you can decide if the notification should be shown to the user, if so, just create a user notification and show it:
Apple doc: local and push notifications
#Jorge Arimany's answer is to send the silent notification to wake up devices to do something, I think it's not the solution this user wants. And I think we still will get the general notification if we do nothing in our UNNotificationServiceExtension class
Pre iOS 10: I dont think it is possible. Here are the reasons. Once when the server sends a push notification to the client to Apple APNS server to send it to the clients, you lose the control of the push notifications. This is one of the reasons apple doesn't always promise 100 percent delivery of the notifications. This implicitly tells you that the Push notifications on the iPhone is handled by the iPhone operating system rather than your App.
Even the push notifications displayed in the Apple iPhone Springboard/dashboard is not in your control.
Users can either control whether he wants to receive the notifications or not.
So i don't think you can control the notifications partly after it is sent from your server.

Prevent auto generated push notification

When we receive a push notification while the application is in the background mode, it automatically uses aps and other parameters like Sound, Badge, Alert to generate a notification that appears on top.
What I want is to prevent that auto generated notification let it call didReceiveRemoteNotification and generate my custom local notification and display it on top and notification centre.
The reason behind this is that the message is customised according to situation which is managed locally after some data received in push notification.
I haven't tried anything, because I couldn't find any solution for this kind of scenario. I don't even know whether it is even possible or not.
Any help or other suggestion that could to solve this other way is highly appreciated.
You can have a look to iOS Silent Notifications here
But you have 2 differences cases :
1 your app is in front, the did receive remote is called, and the notification is not displayed.
2 your app is in background, and I don't think the didreceiveRemove is called.
So in the 2 situations, you will not achieve your goal. You shroud maybe try to customize the notification before sending it
Even when your App is in the background, suspended, inactive or terminated it is woken by a Silent push notification.
(Note: the only scenario when the app is not woken by silent push is when it had been killed off by the user from the control centre)
So you can send a silent push, perform whatever operations you need to perform on the data and then generate a local notification which would go in the tray.

Control which iOS notifications to display

We have iOS push notifications configured and running. However, we would like the user to select which categories are interesting to receive and which are not important and would like to omit receiving those notifications.
Is there any way to do this through Apple push notification itself rather than through the server sending the notifications? (We can change the sent JSON). Can the iPhone send which categories it would like to receive and which are not needed by registering them to Apple? Other choice, can we interrupt the push notification before being shown and decide whether it should be shown or not through a delegate? So far, I can't find an available method to do either.
Any help is appreciated
The short answer is not from the client side. If you want a solution that works 100% of the time you will need to do something on a server which only sends the types of push notifications the user subscribes to.
If your App is in background there is no concept of "categories" of PUSH notifications and you have no control over if they show up in the notification center.
You can examine inbound push when the App is in the foreground and decide on the basis of some meta data to display or not, but that is not a 100% solution.

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