Python 如何序列化DRF中的泛型关系?
我有一个管理员模型,通过泛型关系与其他三个模型关联Python 如何序列化DRF中的泛型关系?,python,django,django-rest-framework,Python,Django,Django Rest Framework,我有一个管理员模型,通过泛型关系与其他三个模型关联 A = 'Active' D = 'Disabled' status = ( (A, 'Active'), (D, 'Disabled') ) limit_choices = (models.Q(app_label='core', model='track') | models.Q(app_label='core', model='comp
A = 'Active'
D = 'Disabled'
status = (
(A, 'Active'),
(D, 'Disabled')
)
limit_choices = (models.Q(app_label='core', model='track') | models.Q(app_label='core',
model='company') | models.Q(app_label='core', model='member') )
content_type = models.ForeignKey(ContentType, limit_choices_to=limit_choices, on_delete=models.CASCADE)
object_id = models.PositiveIntegerField()
content_object = GenericForeignKey('content_type', 'object_id')
status = models.CharField(max_length=7, choices=status, default=D)
class Track(models.Model):
name = models.CharField(max_length=70)
class Company(models.Model):
partner_id = models.ForeignKey(Track, related_name='companies', on_delete=models.CASCADE)
name = models.CharField(max_length=70)
class Member(models.Model):
carrier_id = models.ForeignKey(Track, on_delete=models.CASCADE)
name = models.CharField(max_length=70)
对于序列化,我使用官方文档中的示例
序列化程序.py
class AdministratorSerializer(serializers.RelatedField):
class Meta:
fields = ('id', 'status', )
model = Administrator
def to_representation(self, value):
if isinstance(value, Track):
return value.id
elif isinstance(value, Member):
return value.id
elif isinstance(value, Company):
return value.id
raise Exception('Unexpected type of tagged object')
但我犯了个错误
TypeError at /administrator/
__init__() takes exactly 1 argument (3 given)
请帮助我解决此任务DRF文档说,创建一个通用序列化程序字段(此处,
GenericField
),并连接到序列化程序类中(此处,AdministratorSerializer
)
class GenericField(serializers.RelatedField):
def到_表示(自身、值):
如果存在(值、轨迹):
返回值.id
elif isinstance(值、成员):
返回值.id
elif isinstance(价值,公司):
返回值.id
引发异常(“标记对象的意外类型”)
类管理员序列化程序(序列化程序.ModelSerializer):
generic\u data=GenericField(source='content\u object',read\u only=True)
类元:
字段=('id','status','generic_data')
model=Administrator
序列化程序。RelatedField
应该用于字段,而不是用于模型序列化程序。谢谢,我想这正是我需要的。但是现在我得到了消息AssertionError:Relational字段必须在GenericField
中提供一个queryset`参数,重写get\u queryset
,或者设置read\u=True
`provideread\u only=True
。检查我的更新答案@Jeksonyes它的工作。你能告诉我,如果我能得到什么,我会得到不仅是id,而且还有一个链接到相关模型?我尝试将ModelSerializer更改为HyperlinkedModelSerializer,但这不会更改结果。哦..这似乎是另一个问题。你应该问一个新的:)
class GenericField(serializers.RelatedField):
def to_representation(self, value):
if isinstance(value, Track):
return value.id
elif isinstance(value, Member):
return value.id
elif isinstance(value, Company):
return value.id
raise Exception('Unexpected type of tagged object')
class AdministratorSerializer(serializers.ModelSerializer):
generic_data = GenericField(source='content_object', read_only=True)
class Meta:
fields = ('id', 'status', 'generic_data')
model = Administrator