Google App Engine Python Protorpc Error: __call__(

Question

I'm trying to set up a protorpc service using google app engine python 2.7, and as far as I can remember, this was working fine until it suddenly stopped working and now I can't figure out what's going wrong.

Error:

__call__() takes exactly 1 argument (3 given)
Traceback (most recent call last):
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1511, in __call__
    rv = self.handle_exception(request, response, e)
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1505, in __call__
    rv = self.router.dispatch(request, response)
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1253, in default_dispatcher
    return route.handler_adapter(request, response)
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1040, in __call__
    return self.handler(request, *args, **kwargs)
TypeError: __call__() takes exactly 1 argument (3 given)

Traceback (most recent call last):
  File "/base/data/home/apps/s~smokin-goldshop/15.356936819989737198/handler/orderajax.py", line 78, in main
    util.run_wsgi_app(application)
  File "/base/python27_runtime/python27_lib/versions/1/google/appengine/ext/webapp/util.py", line 98, in run_wsgi_app
    run_bare_wsgi_app(add_wsgi_middleware(application))
  File "/base/python27_runtime/python27_lib/versions/1/google/appengine/ext/webapp/util.py", line 116, in run_bare_wsgi_app
    result = application(env, _start_response)
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1519, in __call__
    response = self._internal_error(e)
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1511, in __call__
    rv = self.handle_exception(request, response, e)
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1505, in __call__
    rv = self.router.dispatch(request, response)
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1253, in default_dispatcher
    return route.handler_adapter(request, response)
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1040, in __call__
    return self.handler(request, *args, **kwargs)
TypeError: __call__() takes exactly 1 argument (3 given)

Code in question:

import logging
from google.appengine.ext import webapp
from google.appengine.ext.webapp import util

from protorpc import messages
from protorpc import remote
from protorpc import service_handlers
from protorpc.service_handlers import ServiceHandlerFactory

from customerhandler import CustomerHandler
from models.customer import Customer


class BlacklistRequest(messages.Message):
    BlackListType = messages.StringField(1, required = True)
    Customer = messages.StringField(2, required = True)

class BlacklistResponse(messages.Message):
    Response = messages.StringField(1, required = True)

class BlacklistAjax(remote.Service):
    @remote.method(BlacklistRequest, BlacklistResponse)
    def ajax(self, request):
        logging.debug("starting")
        tRequest = request
        logging.debug(str(tRequest))
        tArgumentDic = {}
        tCustomerHandler = CustomerHandler()
        tCustomer = Customer()
        logging.debug("Beginning Blacklist of type " + tRequest.BlackListType + " for customer " + tRequest.Customer)

        if(tRequest.BlackListType == 'PA'):
            tCustomerHandler.PaBlacklistCustomer(tRequest.Customer)
            logging.debug("Blacklisted PA")
            return BlacklistResponse(Response = "PA Blacklisted!")
        elif(tRequest.BlackListType == 'Global'):
            tCustomerHandler.GlobalBlacklistCustomer(tRequest.Customer)
            logging.debug("Blacklisted Global")
            return BlacklistResponse(Response = "Global Blacklisted!")
        else:
            logging.debug("Error Blacklisting")
            return BlacklistResponse(Response = "Error Blacklisting")



service_mappings = service_handlers.service_mapping(
    [('/orderajax', OrderAjax),
     ('/blacklist', BlacklistAjax)
    ])

application = webapp.WSGIApplication(service_mappings, debug=True)

def main():
    util.run_wsgi_app(application)

if __name__ == '__main__':
    main()

Answer 1

After banging my head against my desk several times, I did some digging and found the following:

Short Answer

It appears that the webapp2 module does not support protorpc at the current time or vice versa. The only way to use protorpc is to switch to the webapp module instead of webapp2 in which case you also need to revert to Python 2.5 and set threadsafe to false in app.yaml, eg:

# -- snip --   
runtime: python25
threadsafe: false
# -- /snip --

Long Answer

http://code.google.com/p/webapp-improved/issues/detail?id=16 in which the project maintainer (Rodrigo Moraes) states:

Sep 17, 2011

I've been thinking on the subject and the best would be probably to remove webapp2_extras.protorpc. It is only usable with the 2.5 runtime, and has no reason to exist when webapp2 replaces webapp: it is protorpc that needs to support webapp2 in the 2.7 runtime, as it it did with webapp.

Nov 10, 2011

I believe the ProtoRPC project should provide a way.

The webapp2_extras.protorpc package will be removed as it makes no sense to maintain it anymore.

Jan 24, 2012

webapp2_extras.protorpc was removed from version 2.4.

I'd like to support this but there's a bit too much magic involved, so better to have it as a separated, actively maintained project (or if protorpc project supports it by default).

Therefore an issue has been opened in the protorpc project which requests webapp2 support: http://code.google.com/p/google-protorpc/issues/detail?id=38