Kendo treeview expander not coming - asp.net-mvc

Question

i am creating one Kendo treeview as written below
#(Html.Kendo().TreeView()
.Name("treeview")
.Template("<a class='edit-link' onclick=javascript:EditNode(#= item.id #) href='\\#'>#= item.text #</a> <a class='add-link' onclick=javascript:AddNode(#= item.id #) href='\\#'>Add</a>")
.HtmlAttributes(new { #class = "demo-section" })
.DataSource(source =>
{
source.Read(read => read.Action("Read_TemplateData", "Role"));
})
)
and in the controller action i am returning like
public ActionResult Read_TemplateData(string id)
{
IEnumerable<KendoTreeviewModel> result;
var AllPrivileges = ContextService.GetAllPrivilege(Evry.Ecompanion.Web.Common.SessionManager.AuthorizedInfo.UserId);
if (string.IsNullOrEmpty(id))
{
result = AllPrivileges.Where(p => p.Id == p.ParentPrivilegeId).Select(p => new KendoTreeviewModel { text = p.Name, id = p.Id,expanded=false, items = GetChilderns(p.Id) }).ToList();
}
else
{
result = AllPrivileges.Where(p => p.ParentPrivilegeId == Convert.ToInt32(id, CultureInfo.InvariantCulture) && p.Id != Convert.ToInt32(id, CultureInfo.InvariantCulture)).Select(p => new KendoTreeviewModel { text = p.Name, id = p.Id}).ToList();
}
return Json(result, JsonRequestBehavior.AllowGet);
}
public List<KendoTreeviewModel> GetChilderns(int id)
{
var AllPrivileges = ContextService.GetAllPrivilege(Evry.Ecompanion.Web.Common.SessionManager.AuthorizedInfo.UserId);
return AllPrivileges.Where(p => p.ParentPrivilegeId == Convert.ToInt32(id, CultureInfo.InvariantCulture) && p.Id != Convert.ToInt32(id, CultureInfo.InvariantCulture)).Select(p => new KendoTreeviewModel { text = p.Name, id = p.Id }).ToList();
}
and the viewmodel is like
public class KendoTreeviewModel
{
[DataMember]
public int id { get; set; }
[DataMember]
public string text { get; set; }
[DataMember]
public bool expanded { get; set; }
[DataMember]
public List<KendoTreeviewModel> items { get; set; }
}
in the result the Parent and child lists are coming, but the expander in the treeview is not coming
the output is coming without treeview expander, only parent nodes are displaying.
please anybody help me in resolving the issue.
Thanks in advance,
Rudresh

Answer 1

you are not passing Id to your controller
source.Read(read => read.Action("Read_TemplateData", "Role", new{id=#= item.id #}));
You need hasChildren property in order to get the child records
in KendoTreeviewModel class add this property hasChildren then
change
result = AllPrivileges.Where(p => p.Id == p.ParentPrivilegeId).Select(p => new KendoTreeviewModel { text = p.Name, id = p.Id,expanded=false, items = GetChilderns(p.Id) }).ToList();
to
result = AllPrivileges.Where(p => p.Id == p.ParentPrivilegeId).Select(p => new KendoTreeviewModel { text = p.Name, id = p.Id,expanded=false, items = GetChilderns(p.Id),
hasChildren = GetChilderns(p.Id).count() > 0}).ToList();