handlepushSwiftui.swift

import SwiftUI
import os
@main
struct ios14DemoApp: App {
    @StateObject var notificationCenter = NotificationCenter()

    @UIApplicationDelegateAdaptor private var appDelegate: AppDelegate

    var body: some Scene {
        WindowGroup {
            LocalNotificationDemoView(notificationCenter: notificationCenter)
        }
    }
}

class AppDelegate: NSObject, UIApplicationDelegate {
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
        return true
    }
    //No callback in simulator -- must use device to get valid push token
    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        print(deviceToken)
    }
    
    func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
        print(error.localizedDescription)
    }
}

class NotificationCenter: NSObject, ObservableObject {
    @Published var dumbData: UNNotificationResponse?
    
    override init() {
        super.init()
        UNUserNotificationCenter.current().delegate = self
    }
}

extension NotificationCenter: UNUserNotificationCenterDelegate  {
    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        completionHandler([.alert, .sound, .badge])
    }

    func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
        dumbData = response
        completionHandler()
    }

    func userNotificationCenter(_ center: UNUserNotificationCenter, openSettingsFor notification: UNNotification?) { }
}

class LocalNotification: ObservableObject {
    init() {
        
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound]) { (allowed, error) in
            //This callback does not trigger on main loop be careful
            if allowed {
                os_log(.debug, "Allowed")
            } else {
                os_log(.debug, "Error")
            }
        }
    }
    
    func setLocalNotification(title: String, subtitle: String, body: String, when: Double) {
        let content = UNMutableNotificationContent()
        content.title = title
        content.subtitle = subtitle
        content.body = body
        
        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: when, repeats: false)
        let request = UNNotificationRequest.init(identifier: "localNotificatoin", content: content, trigger: trigger)
        UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
        
    }
}

struct LocalNotificationDemoView: View {
    @StateObject var localNotification = LocalNotification()
    @ObservedObject var notificationCenter: NotificationCenter
    var body: some View {
        VStack {
            Button("schedule Notification") {
                localNotification.setLocalNotification(title: "title",
                                                       subtitle: "Subtitle",
                                                       body: "this is body",
                                                       when: 10)
            }
            
            if let dumbData = notificationCenter.dumbData  {
                Text("Old Notification Payload:")
                Text(dumbData.actionIdentifier)
                Text(dumbData.notification.request.content.body)
                Text(dumbData.notification.request.content.title)
                Text(dumbData.notification.request.content.subtitle)
            }
        }
    }
}

extension UIApplicationDelegate {
    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        print("Successfully registered for notifications!")
    }

    func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
        print("Failed to register for notifications: \(error.localizedDescription)")
    }
}



struct PageView: View {
     @State private var selection  = 0
    @State private var localSelectionState = 0
    var body: some View {
        
                     
        TabView(selection: $selection) {
            ForEach(0..<30) { i in
                ZStack {
                    Color.secondary
                    Text("Row: \(i)").foregroundColor(Color(UIColor.systemBackground))
                }.clipShape(RoundedRectangle(cornerRadius: 10.0, style: .continuous))
                //.scaleEffect((selection == i) ? 1.0 :  0.8)
            }
            .padding(.all, 10)
        }.onChange(of: selection, perform: { value in
            withAnimation {
                localSelectionState  = value
            }
        })
        .frame(width: UIScreen.main.bounds.width - 200, height: 200)
        .tabViewStyle(PageTabViewStyle())
        
    }
}


struct PageView_Previews: PreviewProvider {
  static var previews: some View {
    ScrollView {
        LazyHStack {
            PageView()
        }
    }
  }
}

Hi I'm new to Swift so I might be very well wrong, but this didn't work for me as-is. My view didn't update on NotificationCenter.dumbData changes, so I couldn't react to the notification being tapped.

I managed to fix it by adding @Published before the var on line #38. Also, I think that the first two userNotificationCenter methods (#47, #50) should call completionHandler(). Are these changes correct?

Thanks for the gist!

Not calling completionHandler is very bad. The RayWenderlich.com book on Push Notifications is going through final editing for version 3 right now, and it's been completely redone to use SwiftUI in all the examples.

@viktorsec yes you are right, Updated the gist :)