Drag/Drop error: Unable to get value of the property 'rows': object is null or undefined

[Chris]

Hi,

I am testing out the Drag/Drop capabilities of the RadGrid (dragging from one grid to another), and I've come across a problem. It works great when the grid I'm dragging from has more than one row, but if there's one row I get the following JScript error thrown:

Microsoft JScript runtime error: Unable to get value of the property 'rows': object is null or undefined

Here's my ASPX markup:

    <script type="text/javascript">

        function OnClientUpdated(sender, args) {
            var message = "Update (check) was done!";
            var newMsgs = sender.get_value();
            if (newMsgs != 0) {
                sender.show();
                message += (newMsgs == 1) ? (" There is 1 new message!") : (" There are " + newMsgs + " new messages!");
            }
            else {
                message += " There are no new messages!";
            }
        }

    </script>
    <telerik:RadScriptManager ID="RadScriptManager1" runat="server">
    </telerik:RadScriptManager>
    <telerik:RadScriptBlock runat="server" ID="scriptBlock">

        <script type="text/javascript">
                <!--
            function onRowDropping(sender, args) {
                if (sender.get_id() == "<%=RadGrid1.ClientID %>") {
                    var node = args.get_destinationHtmlElement();
                    if (!isChildOf('<%=RadGrid2.ClientID %>', node) && !isChildOf('<%=RadGrid1.ClientID %>', node)) {
                        args.set_cancel(true);
                    }
                }
                else {
                    var node = args.get_destinationHtmlElement();
                    if (!isChildOf('trashCan', node)) {
                        args.set_cancel(true);
                    }
                    else {
                        if (confirm("Are you sure you want to delete this order?"))
                            args.set_destinationHtmlElement($get('trashCan'));
                        else
                            args.set_cancel(true);
                    }
                }
            }

            function isChildOf(parentId, element) {
                while (element) {
                    if (element.id && element.id.indexOf(parentId) > -1) {
                        return true;
                    }
                    element = element.parentNode;
                }
                return false;
            }
                    -->
        </script>

    </telerik:RadScriptBlock>
     <telerik:RadAjaxPanel ID="RadAjaxPanel1" runat="server">
         <telerik:RadSplitter ID="RadSplitter1" Width="100%" runat="server">
         <telerik:RadPane runat="server">
   <telerik:RadGrid ID="RadGrid1" runat="server" AllowFilteringByColumn="true"
                 onneeddatasource="RadGrid1_NeedDataSource" onrowdrop="RadGrid1_RowDrop">
   <MasterTableView AllowCustomSorting="true" AllowPaging="true" DataKeyNames="ID" AllowSorting="true" PageSize="20">

   </MasterTableView>
     <ClientSettings AllowRowsDragDrop="True" AllowColumnsReorder="true" ReorderColumnsOnClient="true">
                    <Resizing AllowColumnResize="true" />
                    <Selecting AllowRowSelect="True" EnableDragToSelectRows="false"/>
                    <Scrolling AllowScroll="true" UseStaticHeaders="true"/>
                          <ClientEvents OnRowDropping="onRowDropping" />
                </ClientSettings>
</telerik:RadGrid>
         </telerik:RadPane>
         <telerik:RadSplitBar runat="server"></telerik:RadSplitBar>
         <telerik:RadPane runat="server">
   <telerik:RadGrid ID="RadGrid2" runat="server" AllowFilteringByColumn="true"
                 onneeddatasource="RadGrid2_NeedDataSource" onrowdrop="RadGrid2_RowDrop">
   <MasterTableView AllowCustomSorting="true" DataKeyNames="ID" AllowPaging="true" AllowSorting="true" PageSize="20">

   </MasterTableView>
     <ClientSettings AllowRowsDragDrop="True" AllowColumnsReorder="true" ReorderColumnsOnClient="true">
                    <Resizing AllowColumnResize="true" />
                             <ClientEvents OnRowDropping="onRowDropping" />

                    <Selecting AllowRowSelect="True" EnableDragToSelectRows="false"/>
                    <Scrolling AllowScroll="true" UseStaticHeaders="true"/>
                </ClientSettings>
</telerik:RadGrid>

         </telerik:RadPane>

         </telerik:RadSplitter>

</telerik:RadAjaxPanel>

  <telerik:RadNotification ID="RadNotification1" runat="server" LoadContentOn="TimeInterval"
        Width="300" Animation="Fade" EnableRoundedCorners="true" EnableShadow="true"
        OnClientUpdated="OnClientUpdated" Title="Notifications" OffsetX="-20" OffsetY="-20"
        TitleIcon="none" UpdateInterval="10000" AutoCloseDelay="1500" OnCallbackUpdate="OnCallbackUpdate">
        <ContentTemplate>
            <asp:Literal ID="lbl" runat="server"></asp:Literal>
        </ContentTemplate>
    </telerik:RadNotification>

Here's my code behind:

public IList<Delivery> _Deliveries
        {
            get { return (List<Delivery>)Session["Deliveries"]; }
            set { Session["Deliveries"] = value; }
        }
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                _Deliveries = new List<Delivery>();
                _Deliveries.Add(new Delivery { ID = 1, Assigned = false, Customer = "Micross", TripDate = DateTime.Today });
                _Deliveries.Add(new Delivery { ID = 2, Assigned = false, Customer = "Test", TripDate = DateTime.Today });
                _Deliveries.Add(new Delivery { ID = 3, Assigned = false, Customer = "Micross3", TripDate = DateTime.Today });
                _Deliveries.Add(new Delivery { ID = 4, Assigned = false, Customer = "Test3", TripDate = DateTime.Today });

                RadGrid1.DataBind();
            }
        }

        private void BindMain()
        {
            RadGrid1.DataBind();
        }

        private void BindSecond()
        {
            RadGrid2.DataSource = _Deliveries.Where(a => a.Assigned == true);
            RadGrid2.DataBind();
        }



        protected void OnCallbackUpdate(object sender, RadNotificationEventArgs e)
        {
            int newMsgs = DateTime.Now.Second % 10;
            if (newMsgs == 5 || newMsgs == 7 || newMsgs == 8 || newMsgs == 9) newMsgs = 0;
            lbl.Text = String.Concat(new object[] { "You have ", newMsgs, " new invoices to process!" });
            RadNotification1.Value = newMsgs.ToString();
        }

        protected void RadGrid2_RowDrop(object sender, GridDragDropEventArgs e)
        {
                foreach (GridDataItem draggedItem in e.DraggedItems)
                {
                    var tmpOrder = _Deliveries.Where(a => a.ID == (long)draggedItem.GetDataKeyValue("ID")).Single();
                    tmpOrder.Assigned = false;
                }

                RadGrid1.Rebind();
                RadGrid2.Rebind();

        }

        protected void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
        {
            RadGrid1.DataSource = _Deliveries.Where(a => a.Assigned == false);

        }

        protected void RadGrid2_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
        {
            RadGrid2.DataSource = _Deliveries.Where(a => a.Assigned == true);

        }

        protected void RadGrid1_RowDrop(object sender, GridDragDropEventArgs e)
        {

                foreach (GridDataItem draggedItem in e.DraggedItems)
                {
                    var tmpOrder = _Deliveries.Where(a => a.ID == (long)draggedItem.GetDataKeyValue("ID")).Single();
                    tmpOrder.Assigned = true;
                }
                RadGrid1.Rebind();
                RadGrid2.Rebind();

        }

Thanks!

[Chris]

Sorry, wrong forum! Meant for the grid forum