Using SPDataSource and DVDropDownList For Filtered Dropdowns

   1: <tr>

   2:      <td width="190px" valign="top" class="ms-formlabel">

   3:            <H3 class="ms-standardheader"><nobr>Status</nobr></H3>

   4:      </td>

   5:      <td width="400px" valign="top" class="ms-formbody">

   6:            <SharePoint:SPDataSource runat="server" DataSourceMode="List" UseInternalName="True" ID="spdatasource1" SelectCommand="&lt;View&gt;&lt;Query&gt;&lt;Where&gt;&lt;Eq&gt;&lt;FieldRef Name=&quot;CurrentState&quot;/&gt;&lt;Value Type=&quot;Text&quot;&gt;{@TestProgramStatus}&lt;/Value&gt;&lt;/Eq&gt;&lt;/Where&gt;&lt;/Query&gt;&lt;ViewFields&gt;&lt;FieldRef Name=&quot;AllowedState&quot;/&gt;&lt;FieldRef Name=&quot;DisplayText&quot;/&gt;&lt;/ViewFields&gt;&lt;/View&gt;" >

   7:                <SelectParameters>

   8:                     <asp:Parameter Name="WebID" DefaultValue="RootWeb" />

   9:                     <asp:parameter Name="ListID" DefaultValue="3C594A44-184E-4B4B-B6D4-5B26F958C5F5" />

  10:                </SelectParameters>

  11:            </SharePoint:SPDataSource>              

  12:            <SharePoint:DVDropDownList runat="server" title="ddStatus" id="ff3{$Pos}" selectedvalue="Select Status" __designer:bind="{ddwrt:DataBind('u',concat('ff3',$Pos),'SelectedValue','SelectedIndexChanged','ID',ddwrt:EscapeDelims(string(@ID)),'@TestProgramStatus')}" datasourceid="spdatasource1" datatextfield="DisplayText" datavaluefield="AllowedState" /><br />                                

  13:            <SharePoint:FieldDescription runat="server" id="ff3description{$Pos}" FieldName="TestProgramStatus" ControlMode="Edit"/>

  14:      </td>

  15: </tr>

This code was added to a custom form in SharePoint Designer. The code is in the XSL stylesheet and this was created to filter a Status Choice field based on its current status. The SelectCommand was used to do the filtering and it is just encoded CAML. This query checks the current status against a separate list that contains the "allowed" status values for the current status. This is used to drive an item through a certain process. A user can select a status but the choices are limited depending on where the item is in the process. The list also has a display text so the dropdown has a more descriptive text of what the user is selecting. The DVDropDownList then updates the actual status field which is a choice field in this case.