API Reference > imodeljs-backend > Elements > Element > onChildAdd onChildAdd MethodProtectedStatic Beta Called when an existing element is about to be updated so that an instance of this class will become its new parent. onChildAdd(_arg: OnChildElementPropsArg): void note throw an exception if the element should not be added note this is the class of the prospective parent Element. Parameter Type Description _arg OnChildElementPropsArg Returns - void Defined in core/backend/src/Element.ts Line 301 Last Updated: 11 June, 2024