How to check if locationManager has updated current location? - ios

Question

I would like to show user's current location on startup, and then keep tracking their location but stop centring on the current location. My idea is to centre on the current location in viewDidLoad(), but I don't know how to wait for locationManager to update the current location before centring. Here are the relevant parts of my code:
var currentLocation : CLLocation?
#IBOutlet weak var mapView: MKMapView!
override func viewDidLoad() {
super.viewDidLoad()
if CLLocationManager.locationServicesEnabled() {
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.delegate = self
locationManager.requestWhenInUseAuthorization()
locationManager.startUpdatingLocation()
// wait for currentLocation to be updated
animateMap(currentLocation!)
}
mapView.showsUserLocation = true
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
currentLocation = locations.last!
}
func animateMap(_ location: CLLocation) {
let region = MKCoordinateRegionMakeWithDistance(location.coordinate, 1000, 1000)
mapView.setRegion(region, animated: true)
}

Answer 1

You need to simply call that animateMap(currentLocation!) function in delegate method didUpdateLocations where you are initializing the currentLocation.
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
currentLocation = locations.last!
animateMap(currentLocation!)
//Either Call `stop​Updating​Location()`
locationManager.stop​Updating​Location()
//Or you can create one boolean property with default value false and compare it inside this method
if !animatedFlag {
animateMap(currentLocation!)
animatedFlag = true
}
}
var animatedFlag = false

Answer 2

// MARK:- Location lattitude longtitude method Delegate Methods
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation])
{
if locationManager.location != nil
{
let locValue = (locationManager.location?.coordinate)!
lat = locValue.latitude
long = locValue.longitude
}
}

Answer 3

Call the animateMap function in didUpdateLocations delegate method, instead of in viewDidLoad. And, allow the map to center only the first time. You can you some bool variable for that.
var isLocationUpdated = false
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
currentLocation = locations.last!
if (!isLocationUpdated)
{
animateMap(currentLocation!)
isLocationUpdated = true
}
}