我有以下django模型:
class Person(models.Model):
name = models.CharField()
location = models.PointField()
我想为这个模型创建一个序列化器/反序列化器。但是我收到的JSON对象是:
{
"userList":[
{
"username": "Foo",
"lat":40.875736,
"lon":8.94382834,
},
{
"username": "Bar",
"lat":40.875736,
"lon":8.94382834,
},
]
}
串行器
class PersonListSerializer(serializers.PersonSerializer):
username = serializers.CharField()
lat = serializers.FloatField()
lon = serializers.FloatField()
class PersonSerializer(serializers.ModelSerializer):
personList = PersonListSerializer
class Meta:
model = Person
是否可以创建自定义序列化器/反序列化器来处理此结构而无需创建其他模型(PersonList)?
提前致谢。
答案 0 :(得分:3)
嗯,这需要一段时间,这绝对是一个很好的学习经历。
您的问题可以分为两个单独的问题:
to_internal_value()
ListSerializer
,而是一个包含单个嵌套字段的字典,其中包含实际列表。你可以在不触及模型的情况下完成。
class ListDictSerializer(serializers.ListSerializer):
def get_field_name(self):
if not hasattr(self.Meta, 'field_name'):
raise ValueError('ListDictSerializer requires defining Meta.field_name overriding get_field_name()')
return self.Meta.field_name
def to_internal_value(self, data):
field_name = self.get_field_name()
return super(ListDictSerializer, self).to_internal_value(data[field_name])
def to_representation(self, data):
field_name = self.get_field_name()
return ReturnDict({
field_name: super(ListDictSerializer, self).to_representation(data)
}, serializer=self
)
@property
def data(self):
# skip over the ListSerializer to get the real data without the
# ReturnList
ret = super(serializers.ListSerializer, self).data
return ReturnDict(ret, serializer=self)
class PersonListSerializer(ListDictSerializer):
class Meta:
field_name = 'userList'
class PersonSerializer(serializers.ModelSerializer):
class Meta:
list_serializer_class = PersonListSerializer
model = Person
fields = ('username', 'lat', 'lon')
username = serializers.CharField(source='name')
lat = serializers.SerializerMethodField(method_name='get_latitude')
lon = serializers.SerializerMethodField(method_name='get_longitude')
def get_latitude(self, instance):
return instance.location.coords[1]
def get_longitude(self, instance):
return instance.location.coords[0]
def to_internal_value(self, data):
return ReturnDict({
'name': data.get('username'),
'location': Point(data['lat'], data['lon']),
}, serializer=self)
请注意,DRF允许您导出任意模型属性(不仅是字段)读/写。也就是说,我们可以通过适当的getter和setter在模型上定义@property
lat
和lon
。但是,Point
之类的地理对象在创建后是不可变的,因此您无法在现有对象上有选择地设置单个坐标。