Control printer output

rbuser

Hi

is ther a way to control printer output, to check if label generated is
already printed or is in spooler?

I want to block the user to print again same label.

Thanks

Sergio Melchiori

nicocizik

Hi Sergio,

See the following article on how to detect if a user printed to the
printer. Once this occurs, you should be able to restrict the data your
user has access to.

http://www.digital-metaphors.com/rbWiki/Output/Printer/Detecting_Whether_Report_Printed_to_Printer

rbuser

Sergio wrote:


Years ago I had to do a similar thing in that I had to detect if:

- the user actually sent output to printer, not to screen, file or
archive
- the user printed the entire range (not a sub range of pages)
- the user did not cancel printing

If all that was true, I had to assume it made it to the printer - that
it was in the windows print spooler and would print ok.

Because there were serious side effects if they printed the same
document twice, when the printdialog closed I popped up a dialog box
telling the user to "click ok if the printing succeeded, or cancel if
printer jammed/failed".

I never did bother to figure out if my print job successfully printed -
I just made sure the end-users got used to waiting for the output!





I had a TppReport in a form by itself (could/should have used
datamodule)

Here's the basic code I used for this:


private
FUserCancelled : Boolean; // did User Cancel print?
FSentToPrinter : Boolean; // did report get sent to the
printer, or just viewed/exported
FPgSetting : TppPageSettingType;
FPgRange : TppPageRangeType;



//---EJB---2005.08.28-----------------------------
procedure TfrmRepPSIView.ResetPrintStateFlags;
begin
FPgSetting := psFirstPage; // force to anything but "all" so we
default to false
FPgRange := prOddPages; // force to anything but "all" so we
default to false
FUserCancelled := False; // assume print not cancel
FSentToPrinter := False; // assume not sent to printer
end;

procedure TfrmRepPSIView.ppReport1PrintDialogCreate(Sender: TObject);
begin
ResetPrintStateFlags; // reset again now because user can print,
cancel, print again
end;

procedure TfrmRepPSIView.ppReport1PrintDialogClose(Sender: TObject);
begin
// we accept only sent to printer, but NOT if printtofile
FSentToPrinter:= ( (ppReport1.PrintDialog.DeviceType='Printer') and
not (ppReport1.PrintDialog.PrintToArchive) and
not (ppReport1.PrintDialog.PrintToFile)
);
end;


//---EJB---2005.08.28-----------------------------
procedure TfrmRepPSIView.ppReport1Cancel(Sender: TObject);
begin
if ( Assigned(ppReport1.CancelDialog) and
ppReport1.CancelDialog.Active and
ppReport1.CancelDialog.Visible
) then FUserCancelled:=True;
end;



and called it with:

frmRepPSIView.ResetPrintStateFlags;
frmRepPSIView.ppReport1.Print;
SentToPrinter := frmRepPSIView.WasSentToPrinterEx; // return
whether or not this was sent to a printer
DidUserCancel := frmRepPSIView.FUserCancelled; // return
whether or not this print job got cancelled

if ( SentToPrinter and (not DidUserCancel)) then
if AskUserToWaitDialog then
...

Cheers,
EdB