public ActionResult GetData(int?id) { IList <Department> list = null; if (!id.HasValue) { list = this.DepartmentRepository.GetRoot(); } else { list = this.DepartmentRepository.GetChildren(id.Value); } IList <DepartmentModel> data = null; if (list != null) { data = list.Select(c => DepartmentModel.From(c)).ToList(); } return(Json(data)); }