ObjectDataSource bound RadComboBox inside RadGrid

[Tim]

I have a EditFormSettings FormTemplate inside a RadGrid that contains two comboboxes:
(Looks something like this):

<FormTemplate>
                    <table>
                        <tr>
                            <td>
                                Inventory Name:
                            </td>
                            <td>
                                <telerik:RadComboBox SelectedValue='<%# Bind( "InventoryId") %>' ID="RadComboBoxInventoryName" runat="server" Height="300px" Width="300px"
                                    Filter="Contains" MarkFirstMatch="true" ChangeTextOnKeyBoardNavigation="false"
                                    DataSourceID="ObjectDataSourceInventoryName" DataTextField="Name" DataValueField="InventoryId" AutoPostBack="true">
                                    <Items>
                                        <telerik:RadComboBoxItem Text="" Value="" Selected="true" />
                                    </Items>
                                </telerik:RadComboBox>
                            </td>
                        </tr>
                        </tr>
                            <tr>
                            <td>
                                Attribute:
                            </td>
                            <td>
                                <telerik:RadComboBox Text='<%# Bind( "Attribute") %>' ID="RadComboBoxAttribute" runat="server" Height="300px" Width="300px"
                                    Filter="Contains" MarkFirstMatch="true" ChangeTextOnKeyBoardNavigation="false"
                                    DataSourceID="ObjectDataSourceAttribute" DataTextField="Attribute" DataValueField="Attribute" AutoPostBack="true">
                                    <Items>
                                        <telerik:RadComboBoxItem Text="" Value="" Selected="true" />
                                    </Items>
                                    <ItemTemplate>
                                        <%# DataBinder.Eval(Container.DataItem, "Type")%>.<%# DataBinder.Eval(Container.DataItem, "Attribute")%>
                                    </ItemTemplate>
                                </telerik:RadComboBox>
                            </td>
                        </tr>
                        <tr>
                            <td align="left" colspan="2">
                                <asp:Button ID="btnUpdate" Text='<%# (Container is GridEditFormInsertItem) ? "Insert" : "Update" %>'
                                    runat="server" CommandName='<%# (Container is GridEditFormInsertItem) ? "PerformInsert" : "Update" %>'>
                                </asp:Button>&nbsp;
                                <asp:Button ID="btnCancel" Text="Cancel" runat="server" CausesValidation="False"
                                CommandName="Cancel"></asp:Button></td>
                        </tr>
                    </table>
                </FormTemplate>

Simple enough... There are two RadComboBoxes with two different ObjectDataSources applied. The ObjectDataSources look like this:

    <asp:ObjectDataSource ID="ObjectDataSourceInventoryName" runat="server"
        TypeName="Ams.Web.BackOffice.InventoryAdapter"
        DataObjectTypeName="Ams.Core.DomainObject.Inventory"
        OldValuesParameterFormatString="original_{0}"
        ConflictDetection="CompareAllValues"
        SelectMethod="GetInventoryForComboBox">
     </asp:ObjectDataSource>

    <asp:ObjectDataSource ID="ObjectDataSourceAttribute" runat="server"
        TypeName="Ams.Web.BackOffice.InventoryTypeAttributesAdapter"
        DataObjectTypeName="Ams.Core.DomainObject.InventoryAttribute_InventoryType"
        OldValuesParameterFormatString="original_{0}"
        ConflictDetection="CompareAllValues"
        SelectMethod="GetAttributeByInventoryId">
<SELECTPARAMETERS>
                <asp:ControlParameter Name="aInventoryId" PropertyName="SelectedValue" ControlID="RadComboBoxInventoryName" />
            </SELECTPARAMETERS>
     </asp:ObjectDataSource>

Note, the ObjectDataSource of interest is the second, as it has a dependency on the first for one of its SelectParameters. When the page loads, I get an error stating:

Could not find control 'RadComboBoxInventoryName' in ControlParameter 'aInventoryId'.

Basically, it reports that it cannot find the control for the aInventoryId parameter (as its not rendered on the page yet).
Is it possible to use ObjectDataSources with parameter dependencies inside an edit form? If not, is there a work around?
Thanks in advance,
Tim
PS. I've tried the $ sign trick some other have posted.. No dice. (Inspected the client "name" attribute for the input control of the RadComboBox --

ctl00$ContentPlaceHolderBody$mImportMappingGrids$RadGridOrigin$ctl00$ctl07$RadComboBoxInventoryName

Nope...

[Rosen]

Hello Tim,

Can you move the DataSources inside the EditForm template and see if this helps?

Sincerely yours,
Rosen
the Telerik team

[Tim]

Did not work -- A control with ID "ObjectDataSource*" could not be found.

[Rosen]

Hello Tim,

You should place the DataSourceControls before the controls to which they are attached.

Sincerely yours,
Rosen
the Telerik team

[Tim]

Fantastic!
Just to clarify. The ObjectDataSource must be inside the <FormTemplate> tag, but *BEFORE* the actual control referencing it.
(I tried n - 1 configurations before posting on the forum, the suggestion being the '1').
Thanks!
Tim

[David]

Hello,

I have a similar scenario: 2 radcomboboxes, second depending on value of the first, both bound to different datasources.

The only trouble is, my radcomboboxes are in GridDataItems, not the FormTemplate. Additionally, I want to have an autocomplete of sorts, similar to how it appears in the following demo:

http://demos.telerik.com/aspnet-ajax/combobox/examples/functionality/filteringcombo/defaultvb.aspx

Is this even possible?

Thanks,

David

[Dimitar Terziev]

Hello David,

There is a code library  here, which you could use as a reference point in order to implement your scenario.

Kind regards,
Dimitar Terziev
the Telerik team