iOS: Do something when a UserNotification is received?

Question

Is it possible to do something when the UserNotification message is delivered to the user every time?

 let tdate = Date(timeIntervalSinceNow: 10)
    let triggerDate = Calendar.current.dateComponents([.year,.month,.day,.hour,.minute,.second,], from: tdate)
    let trigger = UNCalendarNotificationTrigger(dateMatching: triggerDate, repeats: true)

    let identifier = "hk.edu.polyu.addiction.test"
    let request = UNNotificationRequest(identifier: identifier, content: content, trigger: trigger)

    UNUserNotificationCenter.current().removeAllPendingNotificationRequests()
    UNUserNotificationCenter.current().add(request, withCompletionHandler: { (error) in
      if error != nil {
        debugPrint("center.add(request, withCompletionHandler: { (error)")
      } else {
        debugPrint("no error?! at request added place")
      }
    })

This is the code i did to deliver a notification when the user press a button. (i.e., after 10s, the notification appear to the user.)

Even the user not press on the notification, i want some variable of the app updated (assume the app is at the background).

Possible?

Or, as long as this notification is done. another new notification is scheduled, according to some calculations in my app, possible? (not fixed time, cannot use repeat)

No you can't do this thing in background. – Bhavesh Dhaduk Jun 01 '17 at 11:59 — Bhavesh Dhaduk, Jun 01 '17 at 11:59

Saurav · Answer 1 · 2017-06-01T16:14:58.163

0

Yes, it is possible! Need to modify the capabilities :

Enable background fetch in background mode.
Enable remote notification in background mode.
Implement delegate method : application:didReceiveRemoteNotification:fetchCompletionHandler:
This delegate method gets called when the notification arrives on the phone, so you can refresh your data.
When user taps on notification delegate method: didReceiveRemoteNotification gets called and opens the app and user will get latest data in the app.

Apple API reference:

If your payload is not configured properly, the notification might be displayed to the user instead of being delivered to your app in the background. In your payload, make sure the following conditions are true:

The payload’s aps dictionary must include the content-available key with a value of 1. The payload’s aps dictionary must not contain the alert, sound, or badge keys. When a silent notification is delivered to the user’s device, iOS wakes up your app in the background and gives it up to 30 seconds to run.

edited Jun 01 '17 at 16:14

answered Jun 01 '17 at 15:17

Saurav

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If my notification is just a local UserNotification, not a remote one, it will still trigger the method? So can i schedule another Notification using the above code in the application:didReceiveRemoteNotification:fetchCompletionHandler: method? – user6539552 Jun 01 '17 at 15:28
func application(_ application: UIApplication, didReceive notification: UILocalNotification) Any replacement of this function in iOS10? – user6539552 Jun 01 '17 at 15:39
I tried your method, func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) { debugPrint("=========didReceiveRemoteNotification") } Enable background fetch and remote notification, but still the function not get called. Anything i missed? – user6539552 Jun 01 '17 at 15:44
Please check once the payload which server is sending to APNS: { "aps" : { "content-available": 1, sound: "" } } – Saurav Jun 01 '17 at 16:12
No, with local notification it is not possible. – Saurav Jun 01 '17 at 16:23

iOS: Do something when a UserNotification is received?

1 Answers1