models.py: "User" class monkeypatching with signals for MongoDB profiles

from django.db import models

from django.contrib.auth.models import User

import pymongo
mongo = pymongo.Connection()

profiles = mongo['gnusmus']['user.profiles']
profiles.ensure_index('email', unique=True)

scheme = mongo['gnusmus']['user.profiles.scheme']
scheme.ensure_index('title', unique=True)

class UserExtension(object):
    def _get_profile(self):
        doc = profiles.find_one({'email': self.email})
        if doc is None: # not found, init
            self.profile = {}
            return {}
        return doc['profile']

    def _set_profile(self, doc):
        profiles.update({'email': self.email},
                        {'email': self.email, 'profile': doc},
                        True) # upsert profile data

    profile = property(_get_profile, _set_profile)

def hack_user(sender, *args, **kwargs):
    if UserExtension not in sender.__bases__:
        sender.__bases__ += (UserExtension,)

models.signals.pre_init.connect(hack_user, sender=User, dispatch_uid="moprofile_user_patch")