Newbie: trying to twist my head around twisted (and python)

[Jan Bakuwel]

Jean-Paul Calderone wrote:

> The return value of eomReceived is used to determine whether to signal to
> the SMTP client whether the message has been accepted.  Regardless of your
> application logic, if you are taking responsibility for the message, you
> should return a successful result.  If all of your processing is
> synchronous,
> then you simply need to return twisted.internet.defer.succeed(None) at the
> end of the function.  If you have asynchronous processing to do (it does
> not
> appear as though you do), you will need to return a Deferred which only
> fires
> once that processing has been completed.

There's still a bit of mystery in here for me...
I'll be taking responsibility for the message in my code... but perhaps
my code encounters a non resolvable error (such as disc full). In that
case I would like to be able to signal a failure instead of success.

Would the following code do the job "properly"?

    def eomReceived(self):
        # message is complete, store it
        self.lines.append('') # add a trailing newline
        messageData = '\n'.join(self.lines)
        emailMessage = message_from_string(messageData)
        try:
            processEmail(emailMessage)
            return defer.succeed(None)
        except:
            return defer.fail
    #end eomReceived

thanks,
Jan