protected function parentId() {
    switch( $this->position ) {
      case 'root':
        return NULL;

      case 'child':
        return $this->target->getKey();

      default:
        return $this->target->getParentId();
    }
  }
protected function parentId() {
    switch( $this->position ) {
      case 'root':
        return NULL;

      case 'child':
        return $this->target->getKey();

      default:
        return $this->target->getParentId();
    }
  }
protected function parentId ( ) { switch ( $ this -> position ) { case 'root' : return NULL ; case 'child' : return $ this -> target -> getKey ( ) ; default : return $ this -> target -> getParentId ( ) ; } }
Computes the new parent id for the node being moved.

@return int
Computes the new parent id for the node being moved .