Purchase Order Invoice posting with using X++ with custom VendInvoiceInfoLine fields

private boolean postPOInvoice(PurchTable purchTable)

{

    PurchFormLetter         letter      = purchFormLetter::construct(DocumentStatus::Invoice);

    PurchParmUpdate         purchParmUpdate;

    PurchLine               purchLineLocal;

    VendInvoiceInfoTable    vendInvoiceInfoTable;

    VendInvoiceInfoLine     vendInvoiceInfoLine, vendInvoiceInfoLineFrom;    

    boolean                 ret = true;

        

        letter.purchTable(purchTable);

        letter.initParmDefault();

        letter.transDate          (systemdateget());

        letter.specQty            (PurchUpdate::All);

        letter.parmParmTableNum(strFmt("%1-R", vendInvoiceJour.InvoiceId));

        letter.proforma           (false);

        letter.printFormLetter    (false);

        letter.initParameters(letter.purchParmUpdate(), PrintOut::Current);  // Printout

        letter.initLinesQuery();

        while select forUpdate vendInvoiceInfoLine where vendInvoiceInfoLine.ParmId == letter.ParmId()

        {

            purchLineLocal = vendInvoiceInfoLine.purchLine();

            if(purchLineLocal.RemainPurchPhysical != 0)

            {

                vendInvoiceInfoLine.customField1 = <<customField1>>

                vendInvoiceInfoLine.ReceiveNow                = purchLineLocal.PurchQty;

                vendInvoiceInfoLine.setQty(vendInvoiceInfoLine.vendInvoiceInfoTable().Ordering, letter.PurchParmUpdate().creditRemaining);

                vendInvoiceInfoLine.setInventReceiveNow();

                vendInvoiceInfoLine.setLineAmount();

                if (vendInvoiceInfoLine.closed)

                {

                    vendInvoiceInfoLine.remainAfter = 0;

                    vendInvoiceInfoLine.setRemainAfterInvent();

                }

                vendInvoiceInfoLine.update();

            }

            else

            {

                checkFailed(strFmt("Purchase order %1 does not have the remaining qty to invoice", purchTable.PurchId));

            }

        }

        letter.run();

        vendInvoiceJourNew = letter.getOutputContract().parmJournal();

    }   

    info(strfmt("Purchase order posted with Invoice Id %1", vendInvoiceJourNew.InvoiceId));

    return ret;

}