public ActionResult Index(string repositoryName, string folder, string parentFolder, string parentUUID)
        {
            IContentQuery <TextContent> contentQuery = null;
            var repository = new Repository(repositoryName);
            var textFolder = new TextFolder(repository, folder);

            if (string.IsNullOrEmpty(parentFolder))
            {
                contentQuery = textFolder.CreateQuery()
                               .Where(new OrElseExpression(new WhereEqualsExpression(null, "ParentUUID", null), new WhereEqualsExpression(null, "ParentUUID", "")));
            }
            else
            {
                contentQuery = textFolder.CreateQuery().WhereEquals("ParentFolder", parentFolder).WhereEquals("ParentUUID", parentUUID);
            }
            var data = contentQuery.ToDictionary(it => it.UUID, it => it.GetSummary());

            return(Json(data, JsonRequestBehavior.AllowGet));
        }