public function placeOrder(SS_HTTPRequest $request)
 {
     $eventbrite_event_header = $request->getHeader('X-Eventbrite-Event');
     if (!$eventbrite_event_header) {
         return $this->httpError(403);
     }
     if ($eventbrite_event_header !== 'order.placed') {
         return $this->httpError(403);
     }
     if (!$this->isJson()) {
         return $this->httpError(403);
     }
     $json_request = $this->getJsonRequest();
     if (!isset($json_request['config']) || !isset($json_request['api_url'])) {
         return $this->httpError(403);
     }
     $config = $json_request['config'];
     if (!isset($config['action']) || $config['action'] !== 'order.placed') {
         return $this->httpError(403);
     }
     $current_local_url = Controller::join_links(Director::absoluteBaseURL(), $request->getURL());
     if (!isset($config['endpoint_url']) || $config['endpoint_url'] !== $current_local_url) {
         return $this->httpError(403);
     }
     try {
         $this->manager->registerEvent('ORDER_PLACED', $json_request['api_url']);
     } catch (Exception $ex) {
         SS_Log::log($ex->getMessage(), SS_Log::ERR);
         return $this->httpError(500);
     }
     return true;
 }