Delegate method didUpdateLocations is called after trying to use data that has not yet been retrieved from itself - Xcode Swift - ios

Question

I have an NS object (called GoogleSearch) that I use to get the user's location data. These are some global variables created and the init function:
let locationManager = CLLocationManager()
var coordinates: CLLocationCoordinate2D?
override init() {
super.init()
print("1")
DispatchQueue.main.async {
self.locationManager.delegate = self
self.locationManager.desiredAccuracy = kCLLocationAccuracyKilometer
if CLLocationManager.locationServicesEnabled() {
self.locationManager.startUpdatingLocation()
}
}
}
Next, here is my delegate method:
extension GoogleSearch: CLLocationManagerDelegate {
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
print("2")
let userLocation: CLLocation = locations[0] as CLLocation
self.coordinates = CLLocationCoordinate2D(latitude: userLocation.coordinate.latitude, longitude: userLocation.coordinate.longitude)
}
}
Next, I try to access the coordinates (set in the delegate method) in a later function:
func searchForPlaces(completion: #escaping ([place])->()) {
print(coordinates)
}
Finally, in the ViewController that I implement this NSobject, I have the following code in viewDidLoad:
self.googleSearch = GoogleSearch()
DispatchQueue.main.async {
self.googleSearch.searchForPlaces(completion: { (places) in
DispatchQueue.main.async {
self.places = places
self.placesCollectionView.reloadData()
}
})
}
The problem is that printing coordinates in the searchForPlaces functions prints nil because it is run before the delegate method is called. Is there anything I should change in my NSObject or perhaps my ViewController to ensure that I can access coordinates from searchForPlaces() ?
Thank you.

Answer 1

You can achieve in this way:
class GoogleSearch:NSObject {
let locationManager = CLLocationManager()
var coordinates: CLLocationCoordinate2D?
var completionHandler: ((CLLocationCoordinate2D) -> Void)?
override init() {
super.init()
print("1")
}
func searchForPlaces(completion: #escaping (CLLocationCoordinate2D) -> Void) {
self.completionHandler = completion
self.locationManager.delegate = self
self.locationManager.desiredAccuracy = kCLLocationAccuracyKilometer
if CLLocationManager.locationServicesEnabled() {
self.locationManager.stopUpdatingLocation()
self.locationManager.startUpdatingLocation()
}
}
}
extension GoogleSearch: CLLocationManagerDelegate {
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
print("2")
let userLocation: CLLocation = locations[0] as CLLocation
self.coordinates = CLLocationCoordinate2D(latitude: userLocation.coordinate.latitude, longitude: userLocation.coordinate.longitude)
self.completionHandler?(self.coordinates!)
}
}