CheckAVAuthorizationStatus.swift

import AVFoundation

private func showDialogWithTitle(title: String?, msg: String?) {
    let alertController = UIAlertController(title: title, message: msg, preferredStyle: UIAlertControllerStyle.Alert)
    alertController.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
    self.presentViewController(alertController, animated: true, completion: nil)
  }

  @IBAction func didTapButton(sender: AnyObject) {
    let authorizationStatus: AVAuthorizationStatus = AVCaptureDevice.authorizationStatusForMediaType(AVMediaTypeVideo)
    if authorizationStatus == AVAuthorizationStatus.NotDetermined {
      let alertController = UIAlertController(title: nil, message: "Please tap OK button in next dialog to allow the app access camera for taking identity photos.", preferredStyle: UIAlertControllerStyle.Alert)
      alertController.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: { action in
        
        AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo, completionHandler: { (granted: Bool) in
          if granted == true {
            // User granted
            dispatch_async(dispatch_get_main_queue(), {
              self.showDialogWithTitle(nil, msg: "User granted")
            })
          }
          else {
            // User rejected
            dispatch_async(dispatch_get_main_queue(), {
              self.showDialogWithTitle(nil, msg: "User rejected")
            })
          }
        })

      }))
      self.presentViewController(alertController, animated: true, completion: nil)
    }
    else if authorizationStatus == AVAuthorizationStatus.Authorized {
      self.showDialogWithTitle(nil, msg: "User authoried")
    }
    else if authorizationStatus == AVAuthorizationStatus.Denied {
      let alertController = UIAlertController(
          title: nil,
          message: RS_GOTO_SETTINGS_ALLOW_ACCESS_CAMERA,
          preferredStyle: UIAlertControllerStyle.Alert)
        alertController.addAction(UIAlertAction(title: RS_OK, style: UIAlertActionStyle.Cancel, handler: nil))
        alertController.addAction(UIAlertAction(
          title: RS_GOTO_SETTINGS_APP,
          style: UIAlertActionStyle.Default,
          handler: { (action) in
          UIApplication.sharedApplication().openURL(NSURL(string: UIApplicationOpenSettingsURLString)!)
        }))
        self.presentViewController(alertController, animated: true, completion: nil)
    }
  }