import * as q from '../../../../backend/src/Model' ; import { useEffect , useState } from 'react' ; export function useUpdateComponentWhenNodeUpdates ( node ? ) { const [ lastUpdate , setLastUpdate ] = useState ( 0 ) ; useEffect ( ( ) => { if ( ! node ) { return ; } const updateComponent = ( ) => setLastUpdate ( Date . now ( ) ) ; node . onMerge . subscribe ( updateComponent ) ; return function cleanup ( ) { node . onMerge . unsubscribe ( updateComponent ) ; } ; } , [ node ] ) ; return lastUpdate ; }