更改Django Rest Framework序列化器输出结构?

时间:2016-08-30 11:50:56

标签: django django-rest-framework

我有一个像这样的Django模型:

class Sections(models.Model):
    section_id = models.CharField(max_length=127, null=True, blank=True)
    title = models.CharField(max_length=255)
    description = models.TextField(null=True, blank=True)

class Risk(models.Model):
   title = models.CharField(max_length=256, null=False, blank=False)
   section = models.ForeignKey(Sections, related_name='risks')

class Actions(models.Model):
   title = models.CharField(max_length=256, null=False, blank=False)
   section = models.ForeignKey(Sections, related_name='actions')

这样的序列化器:

class RiskSerializer(serializers.ModelSerializer):
   class Meta:
        model = Risk
        fields = ('id', 'title',)

class ActionsSerializer(serializers.ModelSerializer):
    class Meta:
        model = Actions
        fields = ('id', 'title',)

class RiskActionPerSectionsSerializer(serializers.ModelSerializer):
   risks = RiskSerializer(many=True, read_only=True)
   actions = ActionsSerializer(many=True, read_only=True)

   class Meta:
        model = Sections
        fields = ('section_id', 'risks', 'actions')
        depth = 1

   def to_representation(self, instance):
        response_dict = dict()
        response_dict[instance.section_id] = {
        'actions': HealthCoachingActionsSerializer(instance.actions.all(), many=True).data,
        'risks': HealthCoachingRiskSerializer(instance.risks.all(), many=True).data
    }
    return response_dict

在视图上访问RiskActionPerSectionSerializer时,我得到以下输出:

[
{
    "section 1": {
        "risks": [],
        "actions": []
    }
},
{
    "section 2": {
        "risks": [],
        "actions": []
    }
},
.....
]

没关系,但我更愿意这样做:

[

    "section 1": {
        "risks": [],
        "actions": []
    },
    "section 2": {
        "risks": [],
        "actions": []
    }
.....
]

为什么它默认返回一个数组[]而不是一个对象,例如:

{
 "count": 0,
 "next": null,
 "previous": null,
 "results": []
 }

3 个答案:

答案 0 :(得分:1)

您需要覆盖序列化程序类的to_representation()方法。在这个官方文档链接中简要提到: http://www.django-rest-framework.org/api-guide/serializers/#overriding-serialization-and-deserialization-behavior

其他选项是覆盖您的类APIView的get和post方法或它的继承类

答案 1 :(得分:0)

您无法在列表中存储键/值对,['key': {}]将无效,您应该逐个访问项目,就像在您的表示中一样。
由于many=True而返回的数组,这意味着您将许多对象放在序列化程序中,并且它会等待您的序列。

答案 2 :(得分:0)

我看不到导致此输出的ORM查询,但是您的查询返回了多个符合您条件的项目。任何框架的默认行为(更不用说DRF)是将它们放在数组中,然后将其作为结果的“对象数组”返回。