public WebFormsPageCompositionElement(System.Web.UI.Page page) { _masterPage = page; var placeHolders = _masterPage.GetRootControl().GetDescendantControls <ContentPlaceHolder>(); foreach (var nativePlaceHolder in placeHolders) { this.PlaceHolders.Add(nativePlaceHolder.ID, new RenderingsPlaceHolder(nativePlaceHolder.ID)); } this.GlobalPlaceHolders.Add(GlobalLayoutPlaceHolderIds.Head); this.GlobalPlaceHolders.Add(GlobalLayoutPlaceHolderIds.Scripts); this.GlobalPlaceHolders.Add(GlobalLayoutPlaceHolderIds.InternalStateTracking); IsFromLayout = true; }