User Notification Center (iOS, Swift)

# User Notification Center (iOS, Swift) - AppDelegate.swift

import HealthKit
import UserNotifications
import Combine

@main
class AppDelegate: UIResponder, UIApplicationDelegate {
  unc application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        
        // ask the user for notification permissions
    
        let center = UNUserNotificationCenter.current()
        center.requestAuthorization(options: [.alert, .sound, .badge]) { granted, error in
            if error != nil {
              // handle the error here.
            }
            //you're autorized - do whatever you want
        }
  }
}

ViewModel.swift

// call it whenever you're sure that notifications are authorized

func scheduleNotification() {
    let center = UNUserNotificationCenter.current()

    let content = UNMutableNotificationContent()
    content.title = "Notification title"
    content.body = "Notification body"

    let intervalInSeconds = 10
    let trigger = UNTimeIntervalNotificationTrigger(timeInterval: intervalInSeconds, repeats: false)

    let request = UNNotificationRequest(identifier: UUID().uuidString, content: content, trigger: trigger)
    center.add(request)
}