PageContentItemsView.cs

    public class PageContentItemsView  : BucketDataView
    {
        public const string HomePath = "/sitecore/content/MySite3/Home";

        private const string XmlControlKey = "xmlcontrol";
        private const string SelectRenderingDatasource = "Sitecore.Shell.Applications.Dialogs.SelectRenderingDatasource";

        protected PageContentItemsService ContentItemService
        {
            get; set;
        }

        public PageContentItemsView()
        {
            ContentItemService = new PageContentItemsService();
        }

        protected override void GetChildItems(ItemCollection items, Item item)
        {
            base.GetChildItems(items, item);

            if (!PathCheck(item))
            {
                return;
            }

            for (int i = items.Count - 1; i >= 0; i--)
            {
                if (ContentItemService.IsPageContentItemsFolder(items[i]))
                {
                    var folder = items[i];
                    items.Remove(i);

                    if (IsDataSource() || ContentItemService.ShowPageContentItems)
                    { 
                        items.Insert(0, folder);
                    }
                }
            }
        }

        protected virtual bool PathCheck(Item item)
        {
            return item.Paths.Path.StartsWith(HomePath);
        }

        protected virtual bool IsDataSource()
        {
            if (HttpContext.Current != null)
            {
                var request = HttpContext.Current.Request;


                var urlQuery = HttpUtility.ParseQueryString(request.Url.Query ?? String.Empty);
                var urlReferrerQuery =
                    HttpUtility.ParseQueryString(request.UrlReferrer == null
                        ? String.Empty
                        : request.UrlReferrer.Query ?? String.Empty);
                var isDataSourceSelection = urlQuery[XmlControlKey] == SelectRenderingDatasource ||
                                            urlReferrerQuery[XmlControlKey] == SelectRenderingDatasource;
                return isDataSourceSelection;

            }
            return false;
        }
    }