Location Service as a Singleton in Swift, get stuck on "When In Use" - ios

Question

I'm programming an app that needs "Always location" and I decided to use a Singleton to keep tracking active since I need most of the time the location services even in the background.
When I run the application on my iPhone, the console says that the location service is in "When In Use" mode and my protocol don't get the location updates from the LocationManager.
What's wrong with my Singleton (I'm a Swift newbie please be clear in your answers.
Is it a good idea to use a Singleton for Location Services ?
LocationService.swift (UPDATED)
import Foundation
import CoreLocation
protocol LocationServiceDelegate {
func onLocationUpdate(location: CLLocation)
func onLocationDidFailWithError(error: Error)
}
class LocationService: NSObject, CLLocationManagerDelegate {
public static let shared = LocationService()
var delegate: LocationServiceDelegate?
var locationManager: CLLocationManager!
var currentLocation: CLLocation!
private override init() {
super.init()
self.initializeLocationServices()
}
func initializeLocationServices() {
self.locationManager = CLLocationManager()
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.requestAlwaysAuthorization()
self.locationManager.pausesLocationUpdatesAutomatically = false
self.locationManager.delegate = self
self.locationManager.startUpdatingLocation()
}
func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
switch status {
case .restricted:
print("Location access was restricted.")
case .denied:
print("User denied access to location.")
case .notDetermined:
self.locationManager.requestAlwaysAuthorization()
case .authorizedAlways: fallthrough
case .authorizedWhenInUse:
print("User choosed locatiom when app is in use.")
default:
print("Unhandled error occured.")
}
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
self.currentLocation = locations.last!
locationChanged(location: currentLocation)
}
private func locationChanged(location: CLLocation) {
guard let delegate = self.delegate else {
return
}
delegate.onLocationUpdate(location: location)
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
self.locationManager.stopUpdatingLocation()
locationFailed(error: error)
}
private func locationFailed(error: Error) {
guard let delegate = self.delegate else {
return
}
delegate.onLocationDidFailWithError(error: error)
}
}
Then I initialize the singleton :
AppDelegate.swift
let locationService = LocationService.shared
Then my View conforms to my protocol :
ViewController.swift
extension ViewController: LocationServiceDelegate {
func onLocationUpdate(location: CLLocation) {
print("Current Location : \(location)")
}
func onLocationDidFailWithError(error: Error) {
print("Error while trying to update device location : \(error)")
}
}

Answer 1

Yes, You can use singleton for your purpose. Few things you can check with your implementation:
locationManager.pausesLocationUpdatesAutomatically = false.
enable background modes for location updates.
Switch to significant location updates when the app moves to background.

Answer 2

Is it a better way to send notifications to all viewControllers to pass the CLLocation object or its better to conform to my protocol in every controllers ?