Combobox with Treeview

[Regula]

I'me tring to use the Combobox with Treeview functionality.

The first time I choose an item from the tree everything goes smoothly. But if I open again the combox to select the tree I get an javascript error: Message: 'null' is null or not an object. Thus the issue happens only if I choose a node and  after I try to open again the combobox

I've checked the javascript and the error is in the follwoing code:
function OnClientDropDownOpenedHandler(sender, eventArgs) {
            var tree = sender.get_items().getItem(0).findControl("rvt1");
            var selectedNode = tree.get_selectedNode();
            if (selectedNode) {
                selectedNode.scrollIntoView();
            }
        }
The findControl returns a null and when we call the get_selectedNode() we got the exception.
What may be causing this behaviour?

Here is our code:

<script type="text/javascript">

 

        function nodeClicking(sender, args) {

            var comboBox = $find("<%= combo1.ClientID %>");

  

            var node = args.get_node()

            comboBox.set_text(node.get_text());

  

            comboBox.trackChanges();

            comboBox.get_items().getItem(0).set_text(node.get_text());

            comboBox.get_items().getItem(0).set_value(node.get_value());

  

            comboBox.commitChanges();

  

            comboBox.hideDropDown();

  

            // Call comboBox.attachDropDown if:

            // 1) The RadComboBox is inside an AJAX panel.

            // 2) The RadTreeView has a server-side event handler for the NodeClick event, i.e. it initiates a postback when clicking on a Node.

            // Otherwise the AJAX postback becomes a normal postback regardless of the outer AJAX panel.

  

            //comboBox.attachDropDown();

        }

  

        function StopPropagation(e) {

            if (!e) {

                e = window.event;

            }

  

            e.cancelBubble = true;

        }

  

        function OnClientDropDownOpenedHandler(sender, eventArgs) {

            var tree = sender.get_items().getItem(0).findControl("rvt1");

            var selectedNode = tree.get_selectedNode();

            if (selectedNode) {

                selectedNode.scrollIntoView();

            }

        }

    </script>

  

  

<telerik:RadComboBox ID="combo1" runat="server" CausesValidation="false"

    EnableEmbeddedSkins="false" OnClientDropDownOpened="OnClientDropDownOpenedHandler"

    EmptyMessage="select please" MaxHeight="200px"  ShowToggleImage="True"

  

    Width="50%" AllowCustomText="True">

    <ItemTemplate>

        <div id="div1">

            <telerik:RadTreeView ID="rvt1" runat="server" Width="100%" Height="250px"

                DataSourceID="ds1" DataFieldID="ID" DataValueField="ID"

                DataFieldParentID="ParentID" DataTextField="Name" OnClientNodeClicking="nodeClicking" >

                <DataBindings>

                    <telerik:RadTreeNodeBinding Expanded="true" />

                </DataBindings>

            </telerik:RadTreeView>

        </div>

    </ItemTemplate>

    <Items>

        <telerik:RadComboBoxItem Text="" />

    </Items>

</telerik:RadComboBox>

<asp:ObjectDataSource ID="ds2" runat="server"

    EnablePaging="True" OnSelecting="dds2_Selecting"

    SelectMethod="GetList" TypeName="BLL">

    <SelectParameters>

        <asp:Parameter Name="p1" Type="Int32" />

        <asp:Parameter Name="p2" Type="Int32" />

        <asp:Parameter Name="p3" Type="Boolean"  DefaultValue="True" />

    </SelectParameters>

</asp:ObjectDataSource>

[Helen]

Hello,

What is the exact version of the Telerik.Web.UI.dll that you use?
Please find below a sample which works with the latest version - 2011.1.519:

<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<telerik:RadComboBox ID="dataRubricaPai" runat="server" CausesValidation="False"
EnableEmbeddedSkins="false" OnClientDropDownOpened="OnClientDropDownOpenedHandler"
EmptyMessage="Escolha uma rubrica pai" MaxHeight="200px" Skin="UMinho" ShowToggleImage="True"
Width="50%">
<ItemTemplate>
<div id="div1">
<telerik:RadTreeView ID="rvtRubricaPai" runat="server" Width="100%" Height="250px"
OnClientNodeClicking="nodeClicking">
<Nodes>
<telerik:RadTreeNode runat="server" Text="Root RadTreeNode1">
<Nodes>
    <telerik:RadTreeNode runat="server" Text="Child RadTreeNode 1">
    </telerik:RadTreeNode>
    <telerik:RadTreeNode runat="server" Text="Child RadTreeNode 2">
    </telerik:RadTreeNode>
    <telerik:RadTreeNode runat="server" Text="Child RadTreeNode 3">
    </telerik:RadTreeNode>
</Nodes>
</telerik:RadTreeNode>
</Nodes>
</telerik:RadTreeView>
</div>
</ItemTemplate>
<Items>
    <telerik:RadComboBoxItem Text="" />
</Items>
</telerik:RadComboBox>
<script type="text/javascript">
function nodeClicking(sender, args) {
var comboBox = $find("<%= dataRubricaPai.ClientID %>");

var node = args.get_node()
comboBox.set_text(node.get_text());

comboBox.trackChanges();
comboBox.get_items().getItem(0).set_text(node.get_text());
//comboBox.get_items().getItem(0).set_value(node.get_value());

comboBox.commitChanges();

comboBox.hideDropDown();

// Call comboBox.attachDropDown if:
// 1) The RadComboBox is inside an AJAX panel.
// 2) The RadTreeView has a server-side event handler for the NodeClick event, i.e. it initiates a postback when clicking on a Node.
// Otherwise the AJAX postback becomes a normal postback regardless of the outer AJAX panel.

//comboBox.attachDropDown();
}

function StopPropagation(e) {
    if (!e) {
        e = window.event;
    }

    e.cancelBubble = true;
}

function OnClientDropDownOpenedHandler(sender, eventArgs) {
    window.setTimeout(function () {
        var tree = sender.get_items().getItem(0).findControl("rvtRubricaPai");

        var selectedNode = tree.get_selectedNode();
        if (selectedNode) {
            selectedNode.scrollIntoView();
        }
    }, 1000);

}

</script>
</form>

Does it work at your side?

Regards,
Helen
the Telerik team