---
title: Supporting live updates in SwiftUI and Mac Catalyst apps
framework: corelocation
role: article
role_heading: Article
path: corelocation/supporting-live-updates-in-swiftui-and-mac-catalyst-apps
---

# Supporting live updates in SwiftUI and Mac Catalyst apps

Enable background events by adding lifecycle event support.

## Overview

Overview In iOS 17 and later, Core Location supports live updates using Swift concurrency’s async/await capability. In order to adopt live updates, SwiftUI and Mac Catalyst apps need to implement lifecycle event support that enables an app’s @main app to have explicit support for the creation and resumption of background run-loops. This enables the system to deliver Core Location events to the app and allows the delivery of events to resume in the event of return from background, launch of the app, or relaunch after a crash. Adding lifecycle events to SwiftUI To add support for life cycle events, you need to add three components to your app: A shared state using an ObservableObject that maintains instances of CLLocationManager and CLBackgroundActivitySession An AppDelegate object that provides the application(_:didFinishLaunchingWithOptions:) method that handles resuming background activities on return from background or an app relaunch An AppDelegate object in the SwiftUI or Mac Catalyst app’s @main structure In your SwiftUI or Mac Catalyst App, add support for the AppDelegate by adding a shared state through an ObservableObject, and a UIApplicationDelegateAdaptor as an object the app’s @main structure maintains, as shown in the following example:     import SwiftUI

// Shared state that manages the `CLLocationManager` and `CLBackgroundActivitySession`.     @MainActor class LocationsHandler: ObservableObject {              static let shared = LocationsHandler()  // Create a single, shared instance of the object.         private let manager: CLLocationManager         private var background: CLBackgroundActivitySession?

@Published var lastLocation = CLLocation()         @Published var isStationary = false         @Published var count = 0              @Published         var updatesStarted: Bool = UserDefaults.standard.bool(forKey: "liveUpdatesStarted") {             didSet { UserDefaults.standard.set(updatesStarted, forKey: "liveUpdatesStarted") }         }              @Published         var backgroundActivity: Bool = UserDefaults.standard.bool(forKey: "BGActivitySessionStarted") {             didSet {                 backgroundActivity ? self.background = CLBackgroundActivitySession() : self.background?.invalidate()                 UserDefaults.standard.set(backgroundActivity, forKey: "BGActivitySessionStarted")             }         }                   private init() {             self.manager = CLLocationManager()  // Creating a location manager instance is safe to call here in `MainActor`.         }              func startLocationUpdates() {             if self.manager.authorizationStatus == .notDetermined {                 self.manager.requestWhenInUseAuthorization()             }             self.logger.info("Starting location updates")             Task() {                 do {                     self.updatesStarted = true                     let updates = CLLocationUpdate.liveUpdates()                     for try await update in updates {                         if !self.updatesStarted { break }  // End location updates by breaking out of the loop.                         if let loc = update.location {                             self.lastLocation = loc                             self.isStationary = update.isStationary                             self.count += 1                             print("Location \(self.count): \(self.lastLocation)")                         }                     }                 } catch {                     print("Could not start location updates")                 }                 return             }         }              func stopLocationUpdates() {             print("Stopping location updates")             self.updatesStarted = false             self.updatesStarted = false         }      } Next, create an instance of a UIKit AppDelegate class that conforms to SwiftUI’s ObservableObject protocol; this enables the AppDelegate to participate in the SwiftUI’s app-level shared state and manages the resumption of Core Location activities when needed.     import Foundation     import UIKit

class AppDelegate: NSObject, UIApplicationDelegate, ObservableObject {                 func application(_ application: UIApplication, didFinishLaunchingWithOptions                          launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil) -> Bool {             let locationsHandler = LocationsHandler.shared                      // If location updates were previously active, restart them after the background launch.             if locationsHandler.updatesStarted {                 locationsHandler.startLocationUpdates()             }             // If a background activity session was previously active, reinstantiate it after the background launch.             if locationsHandler.backgroundActivity {                 locationsHandler.backgroundActivity = true             }             return true         }     } Finally, include the AppDelegate functionality in your app’s @main structure using a UIApplicationDelegateAdaptor:     @main     struct MyApp: App {         @UIApplicationDelegateAdaptor private var appDelegate: AppDelegate         var body: some Scene {             WindowGroup {                 ContentView()             }         }     }

## See Also

### Essentials

- [Configuring your app to use location services](corelocation/configuring-your-app-to-use-location-services.md)
- [CLLocationManager](corelocation/cllocationmanager.md)
- [CLBackgroundActivitySession](corelocation/clbackgroundactivitysession-3mzv3.md)
- [CLLocationUpdate](corelocation/cllocationupdate.md)
- [Adopting live updates in Core Location](corelocation/adopting-live-updates-in-core-location.md)
- [Monitoring location changes with Core Location](corelocation/monitoring-location-changes-with-core-location.md)