question: private void updateDomObj ( WXComponent component ) { if ( component == null ) { return ; } WXDomObject domObject = mRegistry . get ( component . getRef ( ) ) ; if ( domObject == null ) { return ; } domObject . old ( ) ; component . updateDom ( domObject . clone ( ) ) ; if ( component instanceof WXVContainer ) { WXVContainer container = ( WXVContainer ) component ; int count = container . childCount ( ) ; for ( int i = 0 ; i < count ; ++ i ) { updateDomObj ( container . getChild ( i ) ) ; } } }
target:  Update the specified component's dom and mark it as old.