[XXX] 处的 ManyRelatedManager 对象不是 JSON 可序列化的

Question

我有一个带有 ManyToManyFields 的简单模型，我正在序列化为 JSON：

models.py：

class Meeting(models.Model):
    site = models.ForeignKey(Site)
    meeting_title = models.CharField(default='', max_length=128, blank=True, null=True)
    meeting_team_members = models.ManyToManyField(Team, blank=False, null=False) # hosts
    meeting_visitors = models.ManyToManyField(Visitor, blank=False, null=False) # invited guests

views.py：

instances = Meeting.objects.filter(site=site.id)

for ins in instances: #populate list
     context.append({
        'meeting_title': ins.meeting_title, 
        'meeting_team_members':ins.meeting_team_members.all, 
        'meeting_visitors': ins.meeting_visitors.all, 

json_context = json.dumps(context, cls=DjangoJSONEncoder) #dump list as JSON
return HttpResponse(json_context, 'application/javascript')

但是我得到以下类型错误：

TypeError at /dashboard/get_meetings/
<django.db.models.fields.related.create_many_related_manager.<locals>.ManyRelatedManager object at 0x03406730> is not JSON serializable

Answer 1

如果@Brobin 的建议由于某种原因没有帮助...

meeting_team_members = [x.as_dict() for x in ins.meeting_team_members.all()]

class Team(models.Model):
    # ... example fields
    def as_dict(self):
        context = {
            'pk': self.id,
            'name': self.name,
            'description': self.description,
        }

        if self.image:
            context['image'] = get_thumbnail(self.image, '150').url
            context['full_image'] = self.image.url
        else:
            context['no_image'] = _(u'No image)  # this is just for localization

        return context

编辑

for ins in instances: #populate list
     context.append({
        'meeting_title': ins.meeting_title, 
        'meeting_team_members':[x.as_dict() for x in ins.meeting_team_members.all()]
     })