func checkCamera() {
    let authStatus = AVCaptureDevice.authorizationStatusForMediaType(AVMediaTypeVideo)
    switch authStatus {
        case AVAuthorizationStatus.Authorized: // Do you stuffer here i.e. allowScanning()
        case AVAuthorizationStatus.Denied: alertToEncourageCameraAccessInitially()
        case AVAuthorizationStatus.NotDetermined: alertPromptToAllowCameraAccessViaSetting()
        default: alertToEncourageCameraAccessInitially()
    }

}

func alertToEncourageCameraAccessInitially() {
    var alert = UIAlertController(title: "IMPORTANT", message: "Camera access required for QR Scanning", preferredStyle: UIAlertControllerStyle.Alert)

    alert.addAction(UIAlertAction(title: "Cancel", style: .Default, handler: nil))

    alert.addAction(UIAlertAction(title: "Allow Camera", style: .Cancel, handler: { (alert) -> Void in
        UIApplication.sharedApplication().openURL(NSURL(string: UIApplicationOpenSettingsURLString)!)
    }))

    presentViewController(alert, animated: true, completion: nil)
}

func alertPromptToAllowCameraAccessViaSetting() {

    var alert = UIAlertController(title: "IMPORTANT", message: "Please allow camera access for QR Scanning", preferredStyle: UIAlertControllerStyle.Alert)

    alert.addAction(UIAlertAction(title: "Dismiss", style: .Cancel) { alert in
        if AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo).count > 0 {
            AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo) { granted in
                dispatch_async(dispatch_get_main_queue()) {
                    self.checkCamera() } }
        }
    })

    presentViewController(alert, animated: true, completion: nil)
}