I have the following grid which works as it should.

My question is for the
AWARDED Column
  • Is it possible to only allow one row to be set to "T", ie if any record in the 'uxBiddersStore' is equal to "T" don't allow any other to be set to "T"



<ext:GridPanel runat="server" ID="uxBiddersGrid" Title="Bidders" Flex="20" MinHeight="200" Collapsible="true"
    MarginSpec="5 15 10 5">
    <TopBar>
        <ext:Toolbar runat="server">
            <Items>
                <ext:Button runat="server" ID="uxAddBidderBtn" Text="Add" Icon="ApplicationAdd">
                    <Listeners>
                        <Click Fn="AddBidder" />
                    </Listeners>
                </ext:Button>
                <ext:Button runat="server" ID="uxDeleteBidderBtn" Text="Delete" Icon="ApplicationDelete"
                    Disabled="true">
                    <Listeners>
                        <Click
                            Handler="App.uxBiddersStore.remove(App.uxBidderSelection.getSelection()[0]); App.uxDeleteBidderBtn.disable()" />
                    </Listeners>
                </ext:Button>
            </Items>
        </ext:Toolbar>
    </TopBar>
    <Store>
        <ext:Store runat="server" ID="uxBiddersStore" AutoDataBind="true" PageSize="5">
            <Model>
                <ext:Model runat="server" Name="Bidder" IDProperty="BIDDER_ID" ClientIdProperty="PhantomId">
                    <Fields>
                        <ext:ModelField Name="BIDDER_ID" />
                        <ext:ModelField Name="BIDDER" />
                        <ext:ModelField Name="AWARDED" />
                        <ext:ModelField Name="AWARDED_AMT" />
                        <ext:ModelField Name="BID_ATTACHMENT" />
                    </Fields>
                </ext:Model>
            </Model>
        </ext:Store>
    </Store>
    <ColumnModel>
        <Columns>
            <ext:Column runat="server" Text="Bidder ID" DataIndex="BIDDER_ID" Hidden="true" />
            <ext:Column runat="server" Text="Bidder" DataIndex="BIDDER" Flex="15">
                <Editor>
                    <ext:TextField runat="server" AllowBlank="false" InvalidCls="allowBlank" />
                </Editor>
            </ext:Column>
            <ext:Column runat="server" Text="Has Attachment" DataIndex="BID_ATTACHMENT">
                <Editor>
                    <ext:SelectBox runat="server" AllowBlank="false" InvalidCls="allowBlank" EmptyText="Please Select">
                        <Items>
                            <ext:ListItem Value="F" />
                            <ext:ListItem Value="T" />
                        </Items>
                        <Plugins>
                            <ext:ClearButton runat="server" />
                        </Plugins>
                    </ext:SelectBox>
                </Editor>
            </ext:Column>
            <ext:Column runat="server" Text="Awarded" DataIndex="AWARDED">
                <Editor>
                    <ext:SelectBox runat="server" AllowBlank="false" InvalidCls="allowBlank" EmptyText="Please Select">
                        <Items>
                            <ext:ListItem Value="F" />
                            <ext:ListItem Value="T" />
                        </Items>
                        <Plugins>
                            <ext:ClearButton runat="server" />
                        </Plugins>
                    </ext:SelectBox>
                </Editor>
            </ext:Column>
            <ext:Column runat="server" Text="Awarded Amount" DataIndex="AWARDED_AMT">
                <Editor>
                    <ext:NumberField runat="server" AllowBlank="true" AllowDecimals="true" />
                </Editor>
            </ext:Column>
        </Columns>
    </ColumnModel>
    <SelectionModel>
        <ext:RowSelectionModel runat="server" ID="uxBidderSelection" />
    </SelectionModel>
    <Listeners>
        <Select Handler="#{uxDeleteBidderBtn}.enable()" />
    </Listeners>
    <Plugins>
        <ext:RowEditing runat="server" ID="uxBidderRowEdit" ErrorSummary="false">
            <Listeners>
                <BeforeEdit Handler="if(onBeforeEdit('bidder')) {
														App.uxAddBidderBtn.disable();
                                                        App.uxSaveButton.disable();
                                                        return true;
                                                        }
                                                        else {
                                                        return false; 
                                                        }" />
                <CancelEdit Handler="cancelEditRow('bidder')" />
                <Edit Fn="commitBidderRow" />
            </Listeners>
        </ext:RowEditing>
    </Plugins>
    <BottomBar>
        <ext:PagingToolbar runat="server" />
    </BottomBar>
</ext:GridPanel>