public DirectResult PopulateLookupCategoryTree(string nodeId, string type) { int selectedNodeId; var id = nodeId.Split(new[] { ':' })[0]; int.TryParse(id, out selectedNodeId); ArrayList treeNodeList = null; if (type == "root") { treeNodeList = Lookups.GetLookupCategories(); } var nodes = treeNodeList != null?treeNodeList.ToArray() : default(IEnumerable <object>); return(this.Json(nodes)); }