how to write validateField method in Dynamics AX, d365

validateField method in Dynamics AX, d365

 public boolean validateField(FieldId _fieldIdToCheck)
    {
        boolean ret;

        ret = super(_fieldIdToCheck);

        switch(_fieldIdToCheck)
        {
            case fieldNum(InventTable, HSNCodeTable_IN) :
                  if (this.HSNCodeTable_IN)
                {
                    ret = ret && checkFailed("@TaxGST:LabelCheck");
                }
                break;
        }
        return ret;
    }


Below is an event handler of validate field in D365
/// <summary>
///
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
[DataEventHandler(tableStr(InventTable), DataEventType::ValidatedField)]
public static void InventTable_onValidatedField(Common sender, DataEventArgs e)
{     
                ValidateFieldEventArgs event = e as ValidateEventArgs;
                InventTable InventTable= sender as InventTable;
                //do anything
}

Similarly we can have Posthandler for salesline or inventtable as an example.

[PostHandlerFor(tableStr(SalesLine), tableMethodStr(SalesLine, validateField))]
    public static void SalesLine_Post_validateField(XppPrePostArgs args)
    {
        SalesLine salesLine = args.getThis();
        FieldId fieldId = args.getArg("_fieldId");
        boolean ret = args.getReturnValue();

        switch(fieldId)
        {
            case fieldNum(SalesLine, LinePercent):
                if (salesLine.LinePercent > 100)
                {
                    ret = ret && checkFailed("Wrong");
                }
                break;
        }

        args.setReturnValue(ret);
    }

Thanks,
Vikas Mehta.