/**
  * This is the default handler for exceptions that occur when building the page.
  *
  * By default it adds the exception to the page and uses the view to generate
  * and error page.
  *
  * It can be overridden to provide different functionality such as persisting
  * the exception and redirecting to an error page.
  *
  * @param FrameEx $ex
  * @return string
  */
 protected function handleException(FrameEx $ex)
 {
     $this->processException($ex);
     return $this->view->getErrorPage();
 }