/**
  * Triggers default method.
  * Before it kicks the method, it seeks for methods specified in beforeAction().
  * Default settings are overridden in beforeAction();
  * DB connections and authentications are excuted if they are set true.
  * @param $parameter
  * @return none
  */
 public function action($parameter = null)
 {
     if (method_exists($this, 'beforeAction')) {
         $this->beforeAction();
     }
     if ($this->is_db && !$this->db) {
         $this->connectDB();
     }
     if ($this->is_auth) {
         include_once _AUTH_MANAGER_;
         $this->lang = authManager::auth($this->view);
         if (method_exists($this, 'checkCredential')) {
             $this->checkCredential();
         }
     }
     if (!method_exists($this, $this->default_method)) {
         q4mSystem::haltOnError('The method is not found', get_class($this) . '::' . $this->default_method, __FILE__, __LINE__);
         exit;
     }
     $this->{$this->default_method}($parameter);
 }