symposion_app/symposion/proposals/managers.py
2012-07-12 00:38:39 -04:00

27 lines
No EOL
1.1 KiB
Python

from django.db import models
from django.db.models.query import QuerySet
class CachingM2MQuerySet(QuerySet):
def __init__(self, *args, **kwargs):
super(CachingM2MQuerySet, self).__init__(*args, **kwargs)
self.cached_m2m_field = kwargs["m2m_field"]
def iterator(self):
parent_iter = super(CachingM2MQuerySet, self).iterator()
m2m_model = getattr(self.model, self.cached_m2m_field).through
for obj in parent_iter:
if obj.id in cached_objects:
setattr(obj, "_cached_m2m_%s" % self.cached_m2m_field)
yield obj
class ProposalManager(models.Manager):
def cache_m2m(self, m2m_field):
return CachingM2MQuerySet(self.model, using=self._db, m2m_field=m2m_field)
AdditionalSpeaker = queryset.model.additional_speakers.through
additional_speakers = collections.defaultdict(set)
for additional_speaker in AdditionalSpeaker._default_manager.filter(proposal__in=queryset).select_related("speaker__user"):
additional_speakers[additional_speaker.proposal_id].add(additional_speaker.speaker)