/**
  * Process a submitted post.
  */
 public function submitFormAction()
 {
     // STAGE 3:  Choose, create, and optionally update models using business logic.
     $topicId = $this->getTopicId();
     require_once 'Zend/Filter/StripTags.php';
     $filter = new Zend_Filter_StripTags();
     // only permit digits using ctype_digit()
     $subject = $filter->filter($_POST['subject']);
     $body = $filter->filter($_POST['body']);
     ZFDemoModel_Posts::submit(ZFModule_Forum::getAuthorizationId(), $topicId, $subject, $body);
     // STAGE 4: Apply business logic to create a presentation model for the view.
     // STAGE 5: Choose view and submit presentation model to view.
     $this->setRedirectCode(303);
     // PRG pattern via http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
     $this->_redirect("/forum/index/index/topic/{$topicId}");
 }