我正在尝试在 DRF 3 中创建一个参考应用程序来演示可以创建/更新模型的嵌套序列化器。当尝试创建嵌套模型时,下面的示例代码会带有“** 之后的 *create() 参数必须是映射,而不是列表*”的炸弹。我也不清楚如何处理 .update() 因为在某些情况下我只想建立额外的关系(人)。
样本模型:
from django.db import models
class Person(models.Model):
name = models.CharField(max_length=128)
class Group(models.Model):
name = models.CharField(max_length=128)
persons = models.ManyToManyField(Person, through='Membership')
class Membership(models.Model):
person = models.ForeignKey(Person)
group = models.ForeignKey(Group)
以及序列化器和视图集:
from rest_framework.serializers import ModelSerializer
from rest_framework.viewsets import ModelViewSet
from app.models import Group, Person
class PersonSerializer(ModelSerializer):
class Meta:
model = Person
class GroupSerializer(ModelSerializer):
persons = PersonSerializer(many=True)
def create(self, validated_data):
persons = validated_data.pop('persons')
group = Group.objects.create(**validated_data)
if persons: # Bombs without this check
Person.objects.create(group=group, **persons) # Errors here
return group
class Meta:
model = Group
class PersonModelViewSet(ModelViewSet):
serializer_class = PersonSerializer
queryset = Person.objects.all()
class GroupModelViewSet(ModelViewSet):
serializer_class = GroupSerializer
queryset = Group.objects.all()
我正在尝试发布一些 JSON,插入一个包含两个(相关)人的组:
{
"persons": [
{ "name" : "name 1" },
{ "name" : "name 2" }
],
"name": "group name 1"
}
我不知道是否有更简单的方法,但我设法让它工作的唯一方法是引用组序列化器中的“通过”模型“成员身份”并为 .create() 和 .update( 编写自定义代码)。光是设置 M2M FK 就需要做很多工作。如果有人知道更好的方法,我很乐意听到。
class GroupMembershipSerializer(ModelSerializer):
class Meta:
model = Membership
fields = ('person',)
class GroupCreateSerializer(ModelSerializer):
memberships = GroupMembershipSerializer(many=True, required=False)
def create(self, validated_data):
person_data = validated_data.pop('memberships')
group = Group.objects.create(**validated_data)
for person in person_data:
d=dict(person)
Membership.objects.create(group=group, person=d['person'])
return group
def update(self, instance, validated_data):
person_data = validated_data.pop('memberships')
for item in validated_data:
if Group._meta.get_field(item):
setattr(instance, item, validated_data[item])
Membership.objects.filter(group=instance).delete()
for person in person_data:
d=dict(person)
Membership.objects.create(group=instance, person=d['person'])
instance.save()
return instance
class Meta:
model = Group
class GroupCreateModelViewSet(ModelViewSet):
serializer_class = GroupCreateSerializer
queryset = Group.objects.all()
因此,您可以使用以下方法创建一个包含相关人员的新组:
{
"name" : "Group 1",
"memberships" : [
{ "person" : 1 },
{ "person" : 2 }
]
}
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