How to get location within the camera use in Swift 3/4? - ios

Question

I am coming to this problem where I have a camera and a map view where all I want to do is get the location if the photo is taken using the app that you can access the user's location at the moment the image is captured and extend UIImage to include a property for location and save this location at the same time onto the map view or tableView that you save the image when the picture is taken using the phone's camera. Thank you for any help.
Here is my code. (Camera Controller)
import UIKit
class ViewController: UIViewController, UINavigationControllerDelegate {
#IBOutlet weak var imageView: UIImageView!
#IBOutlet weak var resultLbl: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func CamBtn(_ sender: Any) {
if !UIImagePickerController.isSourceTypeAvailable(.camera) {
return
}
let cameraPicker = UIImagePickerController()
cameraPicker.delegate = self
cameraPicker.sourceType = .camera
cameraPicker.allowsEditing = false
MapViewController.location.requestLocation()
guard let userLocation = MapViewController.location.location else {return}
present(cameraPicker, animated: true)
}
#IBAction func LibBtn(_ sender: Any) {
let picker = UIImagePickerController()
picker.allowsEditing = false
picker.delegate = self
picker.sourceType = .photoLibrary
present(picker, animated: true)
}
}
extension ViewController: UIImagePickerControllerDelegate {
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
dismiss(animated: true, completion: nil)
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
picker.dismiss(animated: true)
resultLbl.text = "Analyzing Image..."
guard let image = info["UIImagePickerControllerOriginalImage"] as? UIImage else {
return
}
}
MapViewController
import Foundation
import UIKit
import MapKit
class MapViewController: UIViewController, CLLocationManagerDelegate {
#IBOutlet weak var mapView: MKMapView!
#IBOutlet weak var tableView: UITableView!
let regionRadius: CLLocationDistance = 1000
var location: CLLocationManager!
let nearbyRequest = MKLocalSearchRequest()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
location = CLLocationManager()
location!.delegate = self
location.desiredAccuracy = kCLLocationAccuracyBest
location.requestAlwaysAuthorization()
location.startUpdatingLocation()
if CLLocationManager.authorizationStatus() == .authorizedWhenInUse {
location!.startUpdatingLocation()
} else {
location!.requestWhenInUseAuthorization()
}
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(true)
mapView.showsUserLocation = true
}
override func viewWillDisappear(_ animated: Bool) {
mapView.showsUserLocation = false
}
func location(manager: CLLocationManager, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
switch status {
case .notDetermined:
print("Not Determined")
case .restricted:
print("Restricted")
case .denied:
print("Denied")
case .authorizedAlways:
print("AuthorizedAlways")
case .authorizedWhenInUse:
print("AuthorizedWhenInUse")
location!.startUpdatingLocation()
}
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {
print("Failed to initialize Map: ", error.description)
}
}

Answer 1

If you want to take the user's location at the time of the photo, you need to request a location update when the user takes a photo and not just start location updates in your other ViewController. You can request a one time location update using CLLocationManager().requestLocation(), but be aware that this is an asynchronous call, so the user might finish taking the photo by the time this returns.
To mitigate this issue, you can either use PromiseKit to get your function to return only when the asynchronous method finished or you can use CLLocationManagerDelegate func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) method and update the picture/MapView as soon as the location update is received.
In MapViewController change var location: CLLocationManager! to static var location = CLLocationManager(), update your MapViewController class accordingly to work with location being a type property and not an implicitly unwrapped instance property. Then in CameraController change your function like so:
#IBAction func CamBtn(_ sender: Any) {
if !UIImagePickerController.isSourceTypeAvailable(.camera) {
return
}
let cameraPicker = UIImagePickerController()
cameraPicker.delegate = self
cameraPicker.sourceType = .camera
cameraPicker.allowsEditing = false
MapViewController.location.requestLocation()
guard let userLocation = MapViewController.location.location else {return}
present(cameraPicker, animated: true)
}
This is not a full example, you still need to add userLocation to your image/MapView, but you should be able to figure that part out by yourself. Also, with this implementation requestLocation() is not guaranteed to return by the time you check its value, so I'd rather use PromiseKit's CLLocationManager.promise() function, which only returns once the location is updated.