If statement is not changing global variable swift - ios

Question

I am trying to set up a function to get my current location in app delegate but when I print(city) at the bottom it returns the original initialized value in the global variable which is "hello", even though I updated the value under the CLGeocoder.
AppDelegate:
import UIKit
import CoreData
import CoreLocation
let appDelegate: AppDelegate = UIApplication.shared.delegate as! AppDelegate
var country = "hello"
var city = "hello"
func setupLocationManager(){
let locationManager = CLLocationManager()
locationManager.requestAlwaysAuthorization()
locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
locationManager.startUpdatingLocation()
}
// Below method will provide you current location.
func getLocation() -> [String]{
let manager = CLLocationManager()
manager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
manager.requestAlwaysAuthorization()
manager.startUpdatingLocation()
manager.desiredAccuracy = kCLLocationAccuracyBest
manager.requestAlwaysAuthorization()
manager.startUpdatingLocation()
let selflocation = manager.location
let latitude: Double = selflocation!.coordinate.latitude
let longitude: Double = selflocation!.coordinate.longitude
print("current latitude :: \(latitude)")
print("current longitude :: \(longitude)")
let location = CLLocation(latitude: latitude, longitude: longitude) //changed!!!
CLGeocoder().reverseGeocodeLocation(location, completionHandler: {(placemarks, error) -> Void in
print(location)
if error != nil {
print("Reverse geocoder failed with error" + (error?.localizedDescription)!)
}
let pm = placemarks![0]
let speed = (selflocation?.speed)!
city = pm.addressDictionary!["City"]! as! String
country = pm.addressDictionary!["Country"]! as! String
if (placemarks?.count)! > 0 {
}
else {
print("Problem with the data received from geocoder")
}
})
print(city)
return [city as! String, country as! String]
}

Answer 1

This is because the geocoding is done asynchronously, so the print(city) is being executed before the geocoding is completed. So I suggest you do this.
func getLocation(completion: #escaping (Array<String>)->()){
let manager = CLLocationManager()
manager.desiredAccuracy = kCLLocationAccuracyBest
manager.requestAlwaysAuthorization()
manager.startUpdatingLocation()
let selflocation = manager.location
let latitude: Double = selflocation!.coordinate.latitude
let longitude: Double = selflocation!.coordinate.longitude
let location = CLLocation(latitude: latitude, longitude: longitude)
CLGeocoder().reverseGeocodeLocation(location, completionHandler: {(placemarks, error) -> Void in
if let error = error {
print(error.localizedDescription)
return
}
if let placemark = placemarks?.first {
if let country = placemark.country, let city = placemark.locality {
completion([city, country])
return
} else {
print("country or city was nil.")
}
} else {
print("Problem with the data received from geocoder")
}
})
}
So instead of calling getLocation() call
getLocation { (location) in
print(location)
}

Answer 2

The problem here is you are getting the value before a new location value is assigned to it. You have to wait a little bit to get the updated value.

Answer 3

reverseGeocodeLocation works asynchronously, so the print statement is actually happening before it finishes. If you have any logic that depends on the results, you'll probably need to put it inside the completion handler closure.

Answer 4

Like the other answer says, reverseGeocodeLocation works asynchronously, so you may want to move the print(city) inside the closure, such as after
else {
print("Problem with the data received from geocoder")
}