序列化程序.py
from rest_framework import serializers
from .models import Flight, Segment, Airport
class DynamicFieldsModelSerializer(serializers.ModelSerializer):
"""
A ModelSerializer that takes an additional `fields` argument that
controls which fields should be displayed.
"""
def __init__(self, *args, **kwargs):
# Instantiate the superclass normally
super(DynamicFieldsModelSerializer, self).__init__(*args, **kwargs)
fields = self.context['request'].query_params.get('fields')
if fields:
fields = fields.split(',')
# Drop any fields that are not specified in the `fields` argument.
allowed = set(fields)
existing = set(self.fields.keys())
for field_name in existing - allowed:
self.fields.pop(field_name)
class SegmentSerializer(serializers.ModelSerializer):
class Meta:
model = Segment
fields = ( # TODO - Could be __all__ if no fine tuning
'id', 'flight_id', 'dep_code', ...
)
class FlightSerializer(DynamicFieldsModelSerializer, serializers.ModelSerializer):
segments = SegmentSerializer(many=True, source='segment_set')
class Meta:
model = Flight
fields = ( # TODO - Could be __all__ if no fine tuning
'id', 'dep_air', 'dest_air', ...
)
class AirportSerializer(DynamicFieldsModelSerializer, serializers.ModelSerializer):
dep_air = FlightSerializer(many=False, source='dep_air_airport')
class Meta:
model = Airport
fields = ('iata_code', 'name', 'continent', 'iso_country',)
启动服务器时出现以下错误:
File "/Users/me/PycharmProjects/fly_baby/flight_data/serializers.py", line 55, in AirportSerializer
dep_air = FlightSerializer(many=False, source='dep_air_airport')
File "/Users/me/PycharmProjects/fly_baby/flight_data/serializers.py", line 15, in __init__
fields = self.context['request'].query_params.get('fields')
KeyError: 'request'
我们的目标是让航班嵌套在机场下,或者反之亦然,但当我使用DynamicFieldsModelSerializer mixin时,这似乎是不可能的。init请求self.context['request'],该上下文对于以下行不存在
dep_air = FlightSerializer(many=False, source='dep_air_airport')
我相信我是想通过某种方式传递上下文,但我不知道这是怎么可能的,因为我的泛型设置很重
额外代码::
views.py
class AirportFlightViewSet(viewsets.ReadOnlyModelViewSet):
serializer_class = FlightSerializer
def get_queryset(self):
return Flight.objects.filter(flight=self.kwargs['airport_pk'])
url.py
router = DefaultRouter()
router.register(r'flights', views.FlightViewSet)
router.register(r'segments', views.SegmentViewSet)
router.register(r'airports', views.AirportViewSet)
flights_router = routers.NestedSimpleRouter(router, r'flights', lookup='flight')
flights_router.register(r'segments', views.FlightSegmentViewSet, basename='flight-segments')
airports_router = routers.NestedSimpleRouter(router, r'airports', lookup='airport')
airports_router.register(r'flights', views.AirportFlightViewSet, basename='airport-flights')
urlpatterns = [
path('', views.index),
path('api/', include(router.urls)),
path('api/', include(flights_router.urls)),
path('api/', include(airports_router.urls)),
]
您可以编辑
DynamicFieldsModelSerializer
使其不依赖于当前的上下文,这样就可以使用.get()
在没有上下文的情况下构造它:但是,请注意,当这样使用子序列化程序时(在本例中为
FlightSerializer
),将始终应用所有字段。但是,这是有道理的,因为在请求机场时,您希望fields
参数会影响机场的字段,而不是航班的字段相关问题 更多 >
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