[Twisted-Python] PB Error (printing exceptions in deferreds)

[Mustafa Sakalsiz]

Hi all,

I am trying to develop an application with twisted and using Pb. I have 
a trouble that I couldn't fix. I tried googling to find an solution, but 
didn't find an exact answer.

The problem is "I don't want exceptions be printed in server side". The 
solution already exists in Pb, if I raise an exception derived from 
pb.Error in a (view, execute, ...) method. However, if I raise the same 
exception in a deferred or callback function, the exception is printed. 
Here is an example,

server.py : Works as I expect
server2.py : Prints the exceptions, which I don't want
client.py : Catches the exception in both ways

Is there a solution which works in any way to avoid printing for 
specific exceptions.

Best regards,
Musti

============== server.py (works well)============
#! /usr/bin/python

from twisted.spread import pb
from twisted.internet import reactor

class MyError(pb.Error):
    pass

class One(pb.Root):
    def remote_broken(self):
        msg = "fall down go boom"
        raise MyError(msg)

def main():
    reactor.listenTCP(8800, pb.PBServerFactory(One()))
    reactor.run()

if __name__ == '__main__':
    main()
=======================================

=========== server2.py (prints exceptions)============
#! /usr/bin/python

from twisted.spread import pb
from twisted.internet import reactor
from twisted.internet import defer

class MyError(pb.Error):
    pass

class One(pb.Root):

    def badFoo(self, result):
        msg = "fall down go boom"
        raise MyError(msg)

    def remote_broken(self):
       d = defer.Deferred()
       d.addCallback(self.badFoo)
       d.callback(0)
       return d
   
def main():
    reactor.listenTCP(8800, pb.PBServerFactory(One()))
    reactor.run()

if __name__ == '__main__':
    main()
==========================================

=== client.py (works same for both server and server2)=======
#! /usr/bin/python

from twisted.spread import pb
from twisted.internet import reactor

def main():
    factory = pb.PBClientFactory()
    reactor.connectTCP("localhost", 8800, factory)
    d = factory.getRootObject()
    d.addCallbacks(got_obj)
    reactor.run()

def got_obj(obj):
    # change "broken" into "broken2" to demonstrate an unhandled exception
    d2 = obj.callRemote("broken")
    d2.addCallback(working)
    d2.addErrback(broken)

def working():
    print "erm, it wasn't *supposed* to work.."

def broken(reason):
    print "got remote Exception"
    print " .type =", reason.type
    reactor.stop()

main()
=============================================