ComboBox with EnableLoadOnDemand filtering *inner* Treeview

[Rubens]

Hi ALL,

I've a combo with treeview for department selection. I want to use combo load on demand capability to filter that treeview, so I'll display all departments which contains entered text. I managed to sign to OnItemsRequest event to search my data source and repopulate that treeview.

But, as that treeview required OnClientNodeClicking event to display department full name ("parent > parent > parent > this"), after postback this message shows up:

Script control 'hierarquia' is not a registered script control. Script controls must be registered using RegisterScriptControl() before calling RegisterScriptDescriptors(). Parameter name: scriptControl

I tried to add RegisterWithScriptManager="FALSE" on treeview and register that client event manually with no success. How should I proceed?

So far I have this code snippets (some code removed):

<telerik:RadComboBox runat="server" ID="selecao" Width="450" AutoPostBack="true"
    LoadingMessage="Loading..." EmptyMessage="Expanda a hierarquia e selecione..." 
    OnClientDropDownOpened="OnClientDropDownOpenedHandler" EnableLoadOnDemand="true"
    MinFilterLength="3" OnInit="selecao_Init" OnItemsRequested="selecao_ItemsRequested" 
    OnClientItemsRequested="OnClientItemsRequested">
    <Items>
        <telerik:RadComboBoxItem Text="" Value="0"/>
    </Items>
    <ItemTemplate>
        <telerik:RadTreeView runat="server" ID="hierarquia" Width="300" 
            RegisterWithScriptManager="FALSE" 
            OnNodeExpand="hierarquia_NodeExpand" OnNodeClick="hierarquia_NodeClick"
            OnClientNodeClicking="nodeClicking" Skin="Default" CausesValidation="false" />
    </ItemTemplate>
</telerik:RadComboBox>

        protected void selecao_Init(object sender, EventArgs e)
        {
            if (this.Hierarquia.Nodes.Count == 0)
            {
                RadTreeNodeCollection parent = this.Hierarquia.Nodes;
                // load data
             }
 
            #region ClientScriptBlock
 
            ScriptManager.RegisterClientScriptBlock(this, typeof(FiltroGenerico), "FiltroGenerico", @"
 
                function nodeClicking(sender, args) {
                    var comboBox = $find(sender._clientStateFieldID.substring(0, sender._clientStateFieldID.length - 26));
                    var node = args.get_node()
 
                    var fullname = '';  // display full treename as requested
                    var pnode = node;
                    while(pnode != null && pnode.get_text != null)
                    {
                        fullname = ' > ' + pnode.get_text() + fullname;
                        pnode = pnode.get_parent();
                    }
                    fullname = fullname.substr(3)
 
                    comboBox.set_text(fullname);
                    comboBox.trackChanges();
                    comboBox.get_items().getItem(0).set_text(fullname);
                    comboBox.commitChanges();
 
                    comboBox.hideDropDown();
                    comboBox.attachDropDown();
                }
 
                function StopPropagation(e) {
                    if (!e)  e = window.event;
                    e.cancelBubble = true;
                }
 
                function OnClientItemsRequested(sender, eventArgs) {
                    var tree = sender.get_items().getItem(0).findControl('hierarquia');
tree.add_nodeClicking(nodeClicking);
                }
 
                function OnClientDropDownOpenedHandler(sender, eventArgs) {
                    var tree = sender.get_items().getItem(0).findControl('hierarquia');
                    var selectedNode = tree.get_selectedNode();
                    if (selectedNode) {
                        selectedNode.scrollIntoView();
                    }
                }", true);
 
            #endregion
        }

[Dimitar Terziev]

Hello Rubens,

You are receiving the following error since you couldn't load controls using load on demand mechanism. This is due to the fact that load on demand is causing callback not post-back to the server and thus the page life cycle is not executed. In general load on demand is used to load data not controls.

Unfortunately you won't be able to implement this scenario using RadTreeView inside RadComboBox with Load on Demand. You should either give up on the load on demand or think of another template for the RadComboBox.

All the best,
Dimitar Terziev
the Telerik team