/**
  * handle event
  *
  * @param string $event
  *
  * @return bool
  */
 protected function handleEvent($event)
 {
     if ($event == self::EVENT_CREATING) {
         $this->setAttribute('salt', $this->_makeSalt());
         $this->setAttribute('password', $this->_encryptPassword());
     } elseif ($event == self::EVENT_UPDATING) {
         if ($this->isDirty(['password'])) {
             $this->setAttribute('password', $this->_encryptPassword());
         }
     }
     return parent::handleEvent($event);
 }