class dxcFileExporter
{
    commaStreamIo       iO;
    custInvoiceTrans    custInvoiceTrans;
    Filename            filename;
    int                 limit = 50;

    public static void main(Args args)
    {
        dxcFileExporter  dxcFileExporter = new dxcFileExporter();
        dxcFileExporter.run();
    }

    void new()
    {
        iO = commaStreamIo::constructForWrite();
        filename = "CustInvoiceExport.csv";
    }

    void run()
    {
        if (Box::yesNo("Do you wish to extract Customer Invoice info to a CSV file?",DialogButton::Yes))
        {
            container header = ["Invoice number",
                                "Invoice Date",
                                "Item Id",
                                "Price",
                                "Qty",
                                "Line Amount"];
            iO.writeExp(header);
            header = conNull();
            while select custInvoiceTrans
                order by InvoiceId,LineNum
            {
                container line =  [custInvoiceTrans.InvoiceId,
                                   custInvoiceTrans.InvoiceDate,
                                   custInvoiceTrans.ItemId,
                                   custInvoiceTrans.SalesPrice,
                                   custInvoiceTrans.Qty,
                                   custInvoiceTrans.LineAmount];
                iO.writeExp(line);
                limit--;
                if (!limit) break;
            }
            System.IO.Stream stream = iO.getStream();
            stream.Position = 0;
            System.IO.StreamReader reader = new System.IO.StreamReader(stream);
            str csvFileContent = reader.ReadToEnd();
            File::SendStringAsFileToUser(csvFileContent,  filename);
            Info(strFmt("invoice Records CSV file %1 Sent to user",filename ));
        }
    }

}