packageDocumentation module import { IPropertyGridModelSource } from "./PropertyGridModelSource" ; beta export interface IPropertyGridEventHandler { onExpansionToggled : ( selectionKey : string ) => void ; } beta export class PropertyGridEventHandler { public constructor ( private _modelSource ) { } param selectionKey public onExpansionToggled = ( selectionKey ) => { this . _modelSource . modifyModel ( ( draftModel ) => { const item = draftModel . getItem ( selectionKey ) ; item . isExpanded = ! item . isExpanded ; } ) ; } ; }