How to set a Timer schedule on appDelegate method? - swift

Question

I need to have my app fetch data and show an alert to user depending on the response, I'm trying to create a function and then call it on appDelegate class...
the function:
func triggerPushMessages(){
Timer.scheduledTimer(withTimeInterval: 60, repeats: true) { (time) in
// I want to perform a request here to show the alert to user
let content = UNMutableNotificationContent()
content.title = "testNotifications on background state"
content.body = "date of notification: \(Date().timeIntervalSinceNow)"
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 5, repeats: false)
let notificationRequest = UNNotificationRequest(identifier: "test", content: content, trigger: trigger)
UNUserNotificationCenter.current().add(notificationRequest, withCompletionHandler: { (err) in
if let error = err {print(error);return}
})
}
}
I created this function to test if notifications would show up after I set the timer but what happens is that when I set timer.schedule function pushNotification doesn't work if I remove timer pushNotification works...
the thing is, I need to request data from an Api first wait for the response and then show the push notification to alert the user...
how can I get on with this?
I call this method on:
func applicationDidEnterBackground(_ application: UIApplication) {
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
self.triggerPushMessages()
}
Is it even possible? how apps like whatsapp, telegram, tinder, can handle/ fetch data on background state and then show notifications to user?
thank you in advance for the answer.
I'd like to add that my 60 seconds request are just for test purposes I'll perform the request once an hour...

Answer 1

You cannot add 60 seconds timer in the app background state. its not allowed in iOS. If you want to show notification to the user even if the app is in the background/not, you can send push notifications from your backend server by integrating the APNS(Apple push notifications). because you are saying that you want to show notification to user, once the api response comes. In this case server will have data and It can decide and send notification to the User.