Exception information in response and finished callbacks

[Simon King]

Hi,

I'm not sure if this is a bug or intentional behaviour, but I've had trouble accessing exception information in response and finished callbacks.

Here is my test script (based on the hello world example from the docs):

#----

from wsgiref.simple_server import make_server

from pyramid.config import Configurator

from pyramid.response import Response

def error(request):

   raise Exception('this is an error message')

def response_callback(request, response):

   print 'response', request.path_qs, response.status_int

def finished_callback(request):

   print 'finished', request.path_qs, request.exception, request.response.status_int

def on_new_request(event):

   request = event.request

   request.add_response_callback(response_callback)

   request.add_finished_callback(finished_callback)

if __name__ == '__main__':

   config = Configurator()

   config.add_route('error', '/error')

   config.add_view(error, route_name='error')

   config.add_subscriber(on_new_request,

                         'pyramid.events.NewRequest')

   app = config.make_wsgi_app()

   server = make_server('0.0.0.0', 8080, app)

   server.serve_forever()

#----

With Pyramid 1.1, If I visit the /error URL I see (amongst other output):

  finished /error this is an error message 200

but with Pyramid 1.3a7, I see:

  finished /error None 200

It looks like the exception view tween deliberately sets the request.exception attribute to None. Does this mean that the documentation for response and finished callbacks should be updated to not refer to that attribute?

(eg. http://readthedocs.org/docs/pyramid/en/1.3-branch/narr/hooks.html#using-response-callbacks)

Also, is there any other way of detecting whether a view raised an exception in one of these callbacks?

Thanks a lot,

Simon