/**
  * Returns true if the user has the right to edit.
  * 
  * @return boolean 
  */
 public function can_edit()
 {
     if (Request::is_student_view()) {
         return false;
     }
     $session_id = Request::get_session_id();
     if ($session_id != 0 && api_is_allowed_to_session_edit(false, true) == false) {
         return false;
     }
     if (!api_is_allowed_to_edit()) {
         return false;
     }
     return true;
 }