title: How to detect compass calibration switch state on iOS
body: <p>I am currently working with the <code>CLLocationManager</code> and want to get informed about the current heading of the device. So far everything works fine, features are implemented and now i try to polish my app.</p>
  
  <p>There is a corner case, if the user will turn off the <code>compass calibration</code> flag in the user settings heading updates will not be send any more to my app. In such a case I want to give the user some feedback, that he has to turn on compass calibration again otherwise my app will not work.</p>
  
  <p>I figured out that in case of the user turns off the <code>location services</code> for my app I will still receive magnetic heading. But if the "compass calibration" setting will be turned of by the user I will not receive any longer heading updates. But how can i identify through the <code>CoreLocation</code> framework that "compass calibration" was turned off?</p>
  
  <p>The "<code>CLLocationManagerDelegate</code>" gives me an update through the </p>
  
  <pre><code>- (void)locationManager:(CLLocationManager*)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status 
  </code></pre>
  
  <p>method. But the status indicates only if the "location services" is in-/active for my app.</p>
  
  <p>I also tried to get some valid informations through the </p>
  
  <pre><code>- (void)locationManager:(CLLocationManager*)manager didFailWithError:(NSError*)error
  </code></pre>
  
  <p><code>delegate</code> method, without any success.</p>
  
  <p>Is there something in the <code>CoreLocation</code> framework that can tell me if "compass calibration" flag is turned on/off.</p>