MKUserTrackingButton doesn't appear because of Firebase? - swift

Question

I added in code the MapView, MKUserTrackingButton button, localManager, DispatchGroup:
let mapView: MKMapView = {
let mapView = MKMapView()
mapView.translatesAutoresizingMaskIntoConstraints = false
return mapView
}()
private var userTrackingButton: MKUserTrackingButton!
private let locationManager = CLLocationManager()
let myGroup = DispatchGroup()
var array = [Car]()
In ViewDidLoad I set:
myGroup.enter()
Get data from Firebase:
observeCars()
Wait until I get all the data from Firebase:
myGroup.notify(queue: DispatchQueue.main) {
self.view.addSubview(self.mapView)
//Here code to set the mapView in the view
self.setupUserTrackingButton()
self.locationManager.delegate = self
self.locationManager.requestWhenInUseAuthorization()
self.locationManager.startUpdatingLocation()
}
Here I set my button in the view:
private func setupUserTrackingButton() {
mapView.showsUserLocation = true
userTrackingButton = MKUserTrackingButton(mapView: mapView)
userTrackingButton.layer.backgroundColor = UIColor(white: 0.5, alpha: 1).cgColor
userTrackingButton.layer.borderColor = UIColor.white.cgColor
userTrackingButton.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(userTrackingButton)
///Code to set in the view the button
}
Class where I set connection to Firebase to get data:
class APIService: NSObject {
class func observeCars(completion: ((_ car: Car) -> Void)?) {
let ref = Database.database().reference()
ref.child("Cars").observe(.childAdded, with: { (snapshot) in
if let dictionary = snapshot.value as? [String: Any] {
let car = Car(dictionary: dictionary)
completion?(car)
}
}, withCancel: nil)
}
}
This is the function (written in the MainViewController) where I get the data from Firebase and add it to the array:
internal func observeCars() {
/////I think this is the part that makes It doesn't appear because
if I delete this part, it works like I aspect
APIService.observeCars {
(car) in
self.array.append(car)
print(self.array.count)
if self.array.count == totalCars {
self.myGroup.leave()
}
}
//////////
}
Any hints? Thanks

Answer 1

I added the MKUserTrackingButton in the mapView:
mapView.addSubview(userLocationButton)
It works to me.