Error creating a global CLLocationManager - ios

Question

Apple Docs suggest not to store your CLLocationManager in a local variable. So I created a global constant outside the scope of my ViewController class just after the import statements. Trying to access the constant inside the class, however, throws compiler errors:
A similarly declared globalDictionaryconstant of type NSMutableDictionary seems to be accessible inside the class.
What is it that I am doing wrong here? Why does the above not work?
Code:
//
// ViewController.swift
// CoreLocationExample
//
//
import UIKit
import CoreLocation
import Foundation
let locationManager = CLLocationManager()
let globalDictionary = NSMutableDictionary()
class ViewController: UIViewController, CLLocationManagerDelegate {
// let locationManager = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
locationManager.delegate = self
locationManager.requestWhenInUseAuthorization()
let dict = [
"name":"John"
]
globalDictionary.addEntries(from: dict)
print(globalDictionary)
}
}
Using Swift 3 on Xcode Version 8.3.1

Answer 1

Apple Docs suggest not to store your CLLocationManager in a local variable.
It means do not create local instance inside a method / function.
please declare like this.
class AppDelegate: UIResponder, UIApplicationDelegate {
//CLLocation Manager
let locationManager = CLLocationManager()
var locValue = CLLocationCoordinate2D()
}
CLLocation Manager or globalDictionary Inside the class.

Answer 2

use singleton class for this
import UIKit
import CoreLocation
public class LocationManager: NSObject,CLLocationManagerDelegate {
public static let sharedInstance = LocationManager()
public lazy var locationManager: CLLocationManager = CLLocationManager()
var globalDictionary = NSMutableDictionary()
public override init() {
super.init()
self.locationManager.requestAlwaysAuthorization()
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.distanceFilter = kCLDistanceFilterNone;
self.locationManager.startUpdatingLocation()
self.locationManager.delegate = self
let dict = [
"name":"John"
]
self.globalDictionary.addEntries(from: dict)
print(self.globalDictionary)
}
// MARK: - Location Manager Delegate
public func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print(error)
}
public func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]){
let newLocation: CLLocation? = locations.last
let locationAge: TimeInterval? = -(newLocation?.timestamp.timeIntervalSinceNow)!
if Double(locationAge!) > 5.0 {
return
}
if Double((newLocation?.horizontalAccuracy)!) < 0 {
return
}
}
public func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
}
}

Answer 3

You can do it in the following way -
class LocationTracker {
static var locationManager: CLLocationManager? = LocationTracker.sharedLocationManager()
class func sharedLocationManager() -> CLLocationManager {
let lockQueue = DispatchQueue(label: "self")
lockQueue.sync {
if _locationManager == nil {
_locationManager = CLLocationManager()
_locationManager?.desiredAccuracy = kCLLocationAccuracyBestForNavigation
_locationManager?.allowsBackgroundLocationUpdates = true
_locationManager?.pausesLocationUpdatesAutomatically = false
}
}
return _locationManager!
}
}
And when you need to call it in your code, you can do the below -
var locationManager: CLLocationManager? = LocationTracker.sharedLocationManager()
you can then add other Location related methods in this class as well like for startt tracking, update location, stoptracking etc.