[Gambas-user] Empty PDF problem - maybe Cairo too slow?

[Rolf-Werner Eilert]

I have been trying around this problem and found a reproduceable behaviour.

To make it short, this is the standard way in my program:

Within SUB Main, I read the mails from the server (contact forms), one 
by one. Each one's data is processed into a pdf (pdf made by Cairo 
class) and a mail text body, then sent to the recipient by e-mail via 
the external script (shelling out).

When the whole thing runs from cron, it will deliver 0 Byte PDFs, but 
the originals on the system are fine (the copies remain in the 
directory). The mailing system does not see any error.

Now is the trick: When I use a ready-made pdf copy and call mail-sending 
SUB with these data directly, it will deliver the PDF correctly. This is 
reproduceable.

So my thought was, it might be that when started from cron, the Gambas 
app runs through so fast that it calls mail sending BEFORE Cairo is 
ready writing the PDF. This would mean Cairo is working on its own. So 
there is a file (you have to give the file name before starting to 
print), but 0 bytes, and that is sent. Only after sending the mail, the 
rest of the data is written and remains in the directory.

How could I check for Cairo to be done with the file before sending the 
mail? Or should I just wait couple of seconds?

Rolf