Help! I Can't get Ajax Binding to work

[Mark Rabjohn]

Hi,

I am trying to get Ajax binding to work with my Grid, but it won't work. When I put the callback URL straight into the browser it says that it can't find the view for my callback:

The view 'ViewSite_FillDomainsList' or its master was not found. The following locations were searched:
~/Views/Admin/ViewSite_FillDomainsList.aspx
~/Views/Admin/ViewSite_FillDomainsList.ascx
~/Views/Shared/ViewSite_FillDomainsList.aspx
~/Views/Shared/ViewSite_FillDomainsList.ascx

The code works in my environment using the Q1 Examples project, so I don't know what's wrong.

My Client side code is in C# and looks like this:

            <%= Html.Telerik().Grid<ApexCMS.SiteAddress>()
                                    .DataBinding(dataBinding => dataBinding.Ajax().Select("ViewSite_FillDomainsList", "Admin", new { guid = Model.Guid.ToString() }))
                                    .Name("DomainListGrid")
                                    .Columns(columns =>
                                    {
                                        columns.Bound(o => o.Scheme);
                                        columns.Bound(o => o.Domain);
                                        columns.Bound(o => o.Port);
                                    })
                                    .Sortable()
            %>

And my server side in VB looks like this:

    <GridAction()> _
    Function ViewSite_FillDomainsList(ByVal guid As String) As ActionResult
        Dim s As ISession = NHibernateHelper.OpenSession()
        Dim site As Site = s.CreateCriteria(Of Site).Add(Expression.Eq("Guid", New Guid(guid))).UniqueResult(Of Site)()
        Dim siteaddresses As IList(Of SiteAddress) = s.CreateCriteria(Of SiteAddress).Add(Expression.Eq("Parent", site)).List(Of SiteAddress)()
        Dim g As GridModel(Of SiteAddress) = New GridModel(Of SiteAddress)(siteaddresses)

        Return View(g)
    End Function

The program generates a GridModel in "g" and also get's past the return View(g) line. It also appears to trace right through the GridAction Attribute, but then crashes looking for the View to render.

Surely this can't be a VB vs. C# issue can it? Hopefully it's a common issue and someone will know what I've done.

Best Regards,

Mark

[Mark Rabjohn]

It looks as though the error that I'm getting is misleading, because the GridAction doesn't filter the output unless it's an AjaxRequest.

When it's an ajax request, the filterContext.Result is changed to a JsonResult object, but it comes through the filter a second time. I can't see the error, so I'm not sure what's going on.

How can I get a look at the root exception?

Mark

[Atanas Korchev]

Hi Mark Rabjohn,

Have you tried running with the debugger? Add a break point in the action method which is responsible for delivering the ajax data.

All the best,
Atanas Korchev
the Telerik team

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[Mark Rabjohn]

Hi Atanas,

The break occurs outside of anywhere that I have open source code for - maybe if I had MVC source open, but I don't.

In anycase, I found that the problem was that my data struct had a circular reference condition (discovered using Fiddler as suggested in another thread).

I used that solution, i.e. write a read-only view class and use LINQ to add wrappers to my list objects. This is a bit of a pain though.

New Server side code:

    <GridAction()> _
    Function ViewSite_FillDomainsList(ByVal guid As String) As ActionResult
        Dim s As ISession = NHibernateHelper.OpenSession()
        Dim site As Site = s.CreateCriteria(Of Site).Add(Expression.Eq("Guid", New Guid(guid))).UniqueResult(Of Site)()
        Dim siteaddresses As IEnumerable(Of SiteAddressView) = From sa In (s.CreateCriteria(Of SiteAddress).Add(Expression.Eq("Parent", site)).List(Of SiteAddress)()) Select New SiteAddressView(sa)

        Return View(New GridModel(Of SiteAddressView)(siteaddresses))
    End Function

Public Class SiteAddressView
    Private _obj As SiteAddress

    Public Sub New(ByVal obj As SiteAddress)
        _obj = obj
    End Sub

    Public ReadOnly Property Guid() As Guid
        Get
            Return _obj.Guid
        End Get
    End Property

    Public ReadOnly Property Scheme() As String
        Get
            Return _obj.Scheme
        End Get
    End Property

    Public ReadOnly Property Domain() As String
        Get
            Return _obj.Domain
        End Get
    End Property

    Public ReadOnly Property Port() As String
        Get
            Return _obj.Port
        End Get
    End Property
End Class

In a perfect world, I guess we'd be able to have attributes to mark properties that can cause circular references, and a JSON encoder that can skip them!

I just need to find the forum postings on getting the Ajax binding to run when the Grid is loaded via Ajax initially - something about including some specific script files I understand.

Best Regards,

Mark