Related ComboBoxes - Second Combo Not Showing Values

[Chris T.]

I feel like I'm missing something here, but I can't seem to get a pair of related comboboxes working. 

When I select something in the primary combo, I get the proper callback, and everything seems to flow correctly.  I threw an alert in the javascript "ItemsLoaded", and the secondary combo has items.  But when the secondary drop down opens, it is blank.  Empty.  Nada.

Grrrr.  Here's the code:

From ucOffenseEdit.ascx (user control for a RadGrid edit/add), the ComboBoxes themselves:

<table cellpadding="0" cellspacing="4" class="InnerContents" width="100%">
  <tr>
    <td style="vertical-align: top" colspan="4">
      <asp:Label ID="lblUCRCode"
        runat="server"
        CssClass="FieldLabel"
        Text="UCR Code" />
      <br />
      <telerik:RadComboBox ID="fldUCRCode"
        runat="server"
        Width="400px"
        Height="168px"
        SkinID="NoSizing"
        Filter="contains"
        SelectedValue='<%# Eval("UCRCodeID") %>'
        OnClientLoad="ComboSetFocus"
        OnClientSelectedIndexChanging="loadOptionalUCRCodes"
        OnItemsRequested="fldUCRCode_ItemsRequested" />
        <br />
    </td>
  </tr>
  <tr>
    <td style="vertical-align: top" colspan="4">
      <asp:Label ID="lblUCROptionalDetailCode"
        runat="server"
        CssClass="FieldLabel"
        Text="Optional Detail Code" />
      <br />
      <telerik:RadComboBox ID="fldUCROptionalDetailCode"
        runat="server"
        EnableViewState="false"
        Width="400px"
        Height="168px"
        SkinID="NoSizing"
        Filter="contains"
        SelectedValue='<%# Eval("UCRCodeID") %>'
        OnClientItemsRequested="ItemsLoaded"
        OnItemsRequested="fldUCROptionalDetailCode_ItemsRequested" />
    </td>
  </tr>

... etc.

</table>

Now the javascript.  For simplicity sake, I'm putting it right in the page where the RadGrid lives.  Eventually (when it works), I'll emit it from the user control's codebehind:

function loadOptionalUCRCodes(sender, eventArgs) {
  var id = sender.get_id();
  var optionalCombo = $find(id.substring(0, id.length - 10) + "fldUCROptionalDetailCode");
  var item = eventArgs.get_item();
  optionalCombo.set_text("Loading...");
  // if a UCR Code is selected...
  if (item.get_index() > 0) {
    // ...load the optional combo
    optionalCombo.requestItems(item.get_value(), false);
  } else {
    optionalCombo.set_text(" ");
    optionalCombo.clearItems();
  }
}
function ItemsLoaded(sender, eventArgs) {
  if (sender.get_items().get_count() > 0) {
    // pre-select the first item
    sender.set_text(sender.get_items().getItem(0).get_text());
    sender.get_items().getItem(0).highlight();
  }
  sender.showDropDown();
}

Finally, the codebehind from the user control:

protected void Page_Load(object sender, EventArgs e) {
  LoadUCRCodes();
  if (!Page.IsCallback) { LoadOptionalUCRCodes(fldUCRCode.SelectedValue); }
}
protected void fldUCRCode_ItemsRequested(object o, RadComboBoxItemsRequestedEventArgs e) {
  LoadUCRCodes();
}
protected void fldUCROptionalDetailCode_ItemsRequested(object o, RadComboBoxItemsRequestedEventArgs e) {
  //passes the value of the UCRCode
  LoadOptionalUCRCodes(e.Text);
}

protected void LoadUCRCodes() {
  if (fldUCRCode.Items.Count == 0) {
    fldUCRCode.Items.Add(new Telerik.Web.UI.RadComboBoxItem(string.Empty, "-1"));
    foreach (DAL.LookupClasses.INCUCRCodeLookupItem l in Lookups.INC.UCRCode.AllItems) {
      if (!l.Parent.HasValue) {
        fldUCRCode.Items.Add(new Telerik.Web.UI.RadComboBoxItem(l.DropDownText, l.ID.ToString()));
      }
    }
  }
}
protected void LoadOptionalUCRCodes(string UCRCodeID) {
  fldUCROptionalDetailCode.Items.Clear();
  if (fldUCROptionalDetailCode.Items.Count == 0) {
    fldUCROptionalDetailCode.Items.Add(new Telerik.Web.UI.RadComboBoxItem(string.Empty, "-1"));
    foreach (DAL.LookupClasses.INCUCRCodeLookupItem l in Lookups.INC.UCRCode.AllItems) {
      if (l.Parent.HasValue) {
        if (l.Parent.ToString() == UCRCodeID) {
          fldUCROptionalDetailCode.Items.Add(new Telerik.Web.UI.RadComboBoxItem(l.DropDownText, l.ID.ToString()));
        }
      }
    }
  }
}

[Princy]

Hello,

Take a look into the following demo.
ComboBox / Related ComboBoxes

Thanks,
Princy.

[Chris T.]

Princy,

Thanks for your response.  Unfortunately, that's where I got most of the code I posted. :)

The frustrating thing is that the data IS getting to the client side.  Fiddler shows it in transit, and Javascript in the ItemsLoaded shows all my items.  Something/someone (me?) is just not telling the dropdown box itself about it. :/

-Chris

[Dimitar Terziev]

Hi Chris,

The experienced behavior seems very strange, especially if the items are really transferred from the server. In order to troubleshoot this issue, please provide a live URL to your page or open a support ticket and send a runnable sample.

Regards,
Dimitar Terziev
the Telerik team