Question

Is it possible to determine programmatically that a user has denied permission to use their location?

Secondly, if a user has denied permission, is it possible to re-prompt the user?

Answer 1

You can determine your authorization status using the authorizationStatus class method on CLLocationManager. This returns a CLAuthorizationStatus which is defined as:

typedef enum {
   kCLAuthorizationStatusNotDetermined = 0,
   kCLAuthorizationStatusRestricted,
   kCLAuthorizationStatusDenied,
   kCLAuthorizationStatusAuthorized
} CLAuthorizationStatus;

The system will prompt the user to authorize your application if the authorization status is undetermined when you attempt to start the location manager.

Additionally, you can check the locationServicesEnabled class method to determine if location is enabled system wide.