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我正在討論Django中的應用程序，它有線程，文章，回覆和投票。投票使用Generic Foreign Keys and Content Types來確保用戶只能對特定主題/帖子/回覆投票一次。GenericForeignKey，ContentType和DjangoRestFramework
投票模式是這樣的：
VOTE_TYPE = (
(-1, 'DISLIKE'),
(1, 'LIKE'),
)
class Vote(models.Model):
user = models.ForeignKey(User)
content_type = models.ForeignKey(ContentType,
limit_choices_to={"model__in": ("Thread", "Reply", "Post")},
related_name="votes")
object_id = models.PositiveIntegerField()
content_object = generic.GenericForeignKey('content_type', 'object_id')
vote = models.IntegerField(choices=VOTE_TYPE)
objects = GetOrNoneManager()
class Meta():
unique_together = [('object_id', 'content_type', 'user')]
投票串行：
class VoteSerializer(serializers.ModelSerializer):
class Meta:
model = Vote
處理投票的觀點：
@api_view(['POST'])
def discussions_vote(request):
if not request.user.is_authenticated():
return Response(status=status.HTTP_404_NOT_FOUND)
data = request.DATA
if data['obj_type'] == 'thread':
content_type = ContentType.objects.get_for_model(Thread)
print content_type.id
info = {
'content_type': content_type.id,
'user': request.user.id,
'object_id': data['obj']['id']
}
vote = Vote.objects.get_or_none(**info)
info['vote'] = data['vote']
ser = VoteSerializer(vote, data=info)
if ser.is_valid():
print "Valid"
else:
pprint.pprint(ser.errors)
return Response()
request.DATA內容：
{u'vote': -1,
u'obj_type': u'thread',
u'obj':
{
...
u'id': 7,
...
}
}
當我投票，Django的REST框架串拋出一個錯誤：
Model content type with pk 149 does not exist.
149是根據contentType的線程模型正確的ID，根據
print content_type.id
我幾乎在造成這種情況的損失......