Validate field method for Form DataSource FormDataFieldEventType::Validating

   /// <summary>

    ///

    /// </summary>

    /// <param name="sender"></param>

    /// <param name="e"></param>

    [FormDataFieldEventHandler(formDataFieldStr(VendTable, VendTable, ProcessToProphet), FormDataFieldEventType::Validated)]

    public static void ProcessToProphet_OnValidated(FormDataObject sender, FormDataFieldEventArgs e)

    {

        var dataObject = sender as FormDataObject;

        var args = e as FormDataFieldCancelEventArgs;

        DirPartyBaseType        dirPartyBaseTypeOrg;

        FormDataSource         dataSource = sender.datasource();

        FormRun    element = dataSource.formRun();

        FormControl     dirtype = element.design(0).controlName("type");

        str  dirPartyBaseTypestr =   dirtype.valueStr();

        dirPartyBaseTypeOrg = str2Enum(dirPartyBaseTypeOrg , dirPartyBaseTypestr);

       // info (strFmt ("%1 ", dirtype.valueStr()) )    ;

      //  DirPartyBaseType selected = any2Enum(dirtype.valueStr());

        if (args != null && dataObject != null)

        {

            var vendTable_ds = dataObject.datasource() as FormDataSource;

            if (vendTable_ds != null)

            {

                VendTable vendRec = vendTable_ds.cursor() as VendTable;

                if (vendRec.RecId > 0)

                {

                    if (dirPartyBaseTypeOrg != DirPartyBaseType::Organization)

                    {

                        boolean doCancel = !checkFailed("Not Organization");

                        args.cancel(doCancel);

                    }

                }

            }

        }

    }

FormDataSourceEventHandler to enable field

 class IPLVendTableTriggerForm_EventHandler

{

    /// <summary>

    ///

    /// </summary>

    /// <param name="sender"></param>

    /// <param name="e"></param>

    [FormDataSourceEventHandler(formDataSourceStr(VendTable, VendTable), FormDataSourceEventType::Activated)]

    public static void VendTable_OnActivated(FormDataSource sender, FormDataSourceEventArgs e)

    {

        VendTable       vendTable = sender.cursor();

        FormDataSource  vendTable_ds = sender.formRun().dataSource("VendTable");

        FormRun         element = sender.formRun();

        FormControl     processTo = element.design(0).controlName("BISTrigger_ProcessTo");

        if(vendTable.ProcessTo == NoYes::Yes)

        {

            processTo.enabled(false);

        }

        else

        {

            processTo.enabled(true);

        }

    }

}