/**
  * Output license keys in XML format
  * 
  * @see Page_Controller::init()
  */
 public function init()
 {
     $data = array();
     $data['Key'] = ShopSettings::get_license_key();
     //Find folders that start with swipestripe_, get their license keys
     $base = Director::baseFolder() . '/swipestripe_';
     $dirs = glob($base . '*', GLOB_ONLYDIR);
     $extensionLicenseKeys = ShopSettings::get_extension_license_keys();
     if ($dirs && is_array($dirs)) {
         $data['Extensions'] = array();
         foreach ($dirs as $dir) {
             $extensionName = str_replace($base, '', $dir);
             if ($extensionName) {
                 $data['Extensions'][]['Extension'] = array('Name' => $extensionName, 'Key' => $extensionLicenseKeys[$extensionName]);
             }
         }
     }
     $xml = new SimpleXMLElement("<?xml version=\"1.0\"?><SwipeStripe></SwipeStripe>");
     $this->array_to_xml($data, $xml);
     header("content-type: text/xml");
     print $xml->asXML();
     exit;
 }