[Solved] Interdependent Filter Dropdowns

[Marc Lee]

I have a RadGrid with State, County and Customer columns.  Each column has a dropdown for filtering.  I need the County filter to be hidden and empty until a state is selected from the State filter.  Once a user has selected a state in the State filter dropdown, the County filter should become visible and contain ONLY counties that correspond to the chosen state.  I can't seem to get the County dropdown to be affected in any way.

Anyone have any ideas?

Here's some code:

    <telerik:RadGrid ID="RadGrid1" runat="server" AllowFilteringByColumn="True" AllowPaging="True"
      AllowSorting="True" AutoGenerateColumns="False" DataSourceID="odsVendorFees" GridLines="None"
      EnableAjaxSkinRendering="true">
      <MasterTableView DataSourceID="odsVendorFees">
        <RowIndicatorColumn>
          <HeaderStyle Width="20px"></HeaderStyle>
        </RowIndicatorColumn>
        <ExpandCollapseColumn>
          <HeaderStyle Width="20px"></HeaderStyle>
        </ExpandCollapseColumn>
        <Columns>
          <telerik:GridBoundColumn DataField="StateName" HeaderText="StateName" SortExpression="State"
            UniqueName="STATENAME">
            <FilterTemplate>
              <asp:TextBox runat="server" ID="TextBox1" Style="display: none;" />
              <telerik:RadComboBox runat="server" ID="ddFilterSN" AutoPostBack="true" DataSourceID="odsStates"
                DataTextField="StateName" DataValueField="StateCode" OnSelectedIndexChanged="ddFilterSN_SelectedIndexChanged"
                Skin="Outlook" AppendDataBoundItems="true">
                <Items>
                  <telerik:RadComboBoxItem runat="server" id="iPubNameBlank" Text="" Value="" />
                  <telerik:RadComboBoxItem runat="server" id="iPubNameClear" ForeColor="Blue" Font-Italic="true"
                    Text="Show All States" Value="Clear Search" />
                </Items>
              </telerik:RadComboBox>
            </FilterTemplate>
          </telerik:GridBoundColumn>
          <telerik:GridBoundColumn DataField="CountyName" HeaderText="CountyName" SortExpression="County"
            UniqueName="COUNTYNAME">
            <FilterTemplate>
              <asp:TextBox runat="server" ID="TextBox2" Style="display: none;" />
              <telerik:RadComboBox runat="server" ID="ddFilterCN" AutoPostBack="true" DataTextField="CountyName"
                DataValueField="CountyName" OnSelectedIndexChanged="ddFilterCN_SelectedIndexChanged"
                Skin="Outlook" AppendDataBoundItems="true">
                <Items>
                  <telerik:RadComboBoxItem runat="server" id="iPubNameBlank" Text="" Value="" />
                  <telerik:RadComboBoxItem runat="server" id="iPubNameClear" ForeColor="Blue" Font-Italic="true"
                    Text="Show All Counties" Value="Clear Search" />
                </Items>
              </telerik:RadComboBox>
            </FilterTemplate>
          </telerik:GridBoundColumn>
          <telerik:GridBoundColumn DataField="CustomerName" HeaderText="CustomerName" SortExpression="Customer Name"
            UniqueName="CustomerName">
          </telerik:GridBoundColumn>
        </Columns>
      </MasterTableView>
    </telerik:RadGrid>

    Public Sub ddFilterSN_SelectedIndexChanged(ByVal sender As Object, ByVal e As RadComboBoxSelectedIndexChangedEventArgs)
        ' filter the grid based on state name
        Dim filterItem As GridFilteringItem = DirectCast(RadGrid1.MasterTableView.GetItems(GridItemType.FilteringItem)(0),  _
        GridFilteringItem)
        Dim ddCN As RadComboBox = CType(filterItem("COUNTYNAME").Controls(3), RadComboBox)

        If e.Value = "Clear Search" Then
            ddCN.Visible = False
            RadGrid1.MasterTableView.FilterExpression = Nothing
            RadGrid1.Rebind()
        Else
            Dim lstCounties As List(Of County) = CountyDAL.GetCountiesByStateCode(e.Value)

            TryCast(filterItem("STATENAME").Controls(1), TextBox).Text = e.Text
            filterItem.FireCommandEvent("Filter", New Pair("EqualTo", "STATENAME"))

            ddCN.DataSource = lstCounties
            ddCN.DataBind()
            ddCN.Visible = False
            RadGrid1.DataBind()
        End If
    End Sub

[Princy]

Hello Marc,

Check out the following online demo which illustrtates on how combobox instances can interact with each other. You can implement the same in grid. You can use the onClientLoad event of the comboboxes to access the comboboxes instead of the pageLoad client event.
js:

 var countriesCombo;
function ClientLoad(sender, args)
  {
      countriesCombo = sender;
  }

Hope this helps..
Princy.

[Dimo]

....and this is the demo Princy is talking about :)

http://demos.telerik.com/aspnet-ajax/combobox/examples/functionality/multiplecomboboxes/defaultcs.aspx


Best wishes,
Dimo
the Telerik team

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[Marc Lee]

Thanks for your efforts, but I'm not having a problem with the comboboxes specifically.  I know how to make them interact with each other under normal circumstances.  In this case, however, I can't even get the 2nd RadComboBox to respond to any event - specifically with rebinding to a datasource.  If I put a code break within a specific event *after* the rebinding has occurred, I can see that the 2nd RadComboBox has the data, but it does not show up in real time.  It's almost as if the grid needs to be refreshed, but I've tried rebinding the grid and even rebinding the MasterTableView, but nothing works.

I'm sure I'm missing something simple, but I just can't see what it is.


Thanks!

Marc

[Dimo]

Hi Marc Lee,

Here is one more demo that you can review:

http://demos.telerik.com/aspnet-ajax/grid/examples/programming/filtertemplate/defaultcs.aspx

You can control the RadComboBoxes' visibility in RadGrid_PreRender by using

GridItem[] items = RadGrid1.MasterTableView.GetItems(GridItemType.FilteringItem);
(items[0] as GridFilteringItem).FindControl("RadComboBoxCity").Visible = true;

Regards,
Dimo
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Watch a video on how to optimize your support resource searches and check out more tips on the blogs.

[Marc Lee]

Dimo,

Thanks!  Between your suggested demo and the Google-style filtering demo, I was able to get this working.  Thanks for coming back and posting another possible solution!


Marc