Check of Location permissions set - ios

Question

My iOS app has been rejected by Apple as the app crashes if a user selected "Dont allow" location access. And the proceeds to tap on my Map button.
How can I wrap this button in check to see if the user has given permission, And if not how can I ask for permission again?
//Map Button Action - Opens Maps - Gives choice of Google or Apple maps
#IBAction func googleMapBtn(_ sender: UIButton) {
UIDevice.current.isBatteryMonitoringEnabled = true
let state = UIDevice.current.batteryState
//If user is in Loop - Cant open maps
if state == .charging {
print("In Loop - Cant open maps")
}
//Present Map Options
else {
let alertController = UIAlertController.init(title: "Open Map", message: "", preferredStyle: .alert)
alertController.addAction(UIAlertAction.init(title: "Google Maps", style: .default, handler: { (action) in
self.googleMapsOpen()
}))
alertController.addAction(UIAlertAction.init(title: "Apple Maps", style: .default, handler: { (action) in
self.appleMapsOpen()
}))
alertController.addAction(UIAlertAction.init(title: "Back", style: .default, handler: { (action) in
self.dismiss(animated: true, completion: nil)
}))
self.present(alertController, animated: true) {
}
}
}
The code crashes whenever a user selects a map type Google/Apple and the self.googleMapsOpen() or self.appleMapsOpen() are executed. Specifically is crashed on the let scheme=
func googleMapsOpen(){
print("Google Maps Pressed")
let scheme = "comgooglemaps://?center=\(LocationManager.sharedInstance.location.coordinate.latitude),\(LocationManager.sharedInstance.location.coordinate.longitude)&zoom=15"
self.open(scheme: scheme)
}
func appleMapsOpen(){
print("Apple Maps Pressed")
let scheme = "http://maps.apple.com/?ll=\(LocationManager.sharedInstance.location.coordinate.latitude),\(LocationManager.sharedInstance.location.coordinate.longitude)&zoom=15"
self.open(scheme: scheme)
}

Answer 1

You can do something like this :
func checkLocationPermissionEnabled()
{
if CLLocationManager.locationServicesEnabled()
{
switch(CLLocationManager.authorizationStatus())
{
case .notDetermined, .restricted, .denied:
self.openDeviceLocationSetting()
return
case .authorizedAlways, .authorizedWhenInUse:
//do whatever you want to do with location
return
}
}
else
{
self.openDeviceLocationSetting()
return
}
}
func openDeviceLocationSetting()
{
let alertController = UIAlertController(title: "", message:"For best results, let your device turn on location using Google's location service.", preferredStyle: .alert)
let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default) {
UIAlertAction in
self.isAlertShowing = false
let settingsUrl = NSURL(string: UIApplicationOpenSettingsURLString)
if let url = settingsUrl {
UIApplication.shared.openURL(url as URL)
}
}
let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.default) {
UIAlertAction in
}
alertController.addAction(okAction)
alertController.addAction(cancelAction)
self.present(alertController, animated: true, completion: nil)
}