Django Serializer HiddenField隐藏字段实例

# 假如我定义了一个serliazer，shop和status都是自动判断后赋值的
# 用HiddenField定义字段，default方法来写具体赋值函数
# default方法是一个类，需要重写set_context的方法
from rest_framework.compat import (
 InvalidTimeError, MaxLengthValidator, MaxValueValidator,
 MinLengthValidator, MinValueValidator, unicode_repr, unicode_to_repr
)
class CurrentShopDefault(object):
 def set_context(self, serializer_field):
  self.shop = serializer_field.context['request'].user.shop

 def __call__(self):
  return self.shop

 def __repr__(self):
  return unicode_to_repr('%s()' % self.__class__.__name__)

class CurrentStatus(object):
 def set_context(self, serializer_field):
  user_info = serializer_field.context['request'].user
  if user_info.shop.shop_type == 'SHOP_TYPE_COMCIRCLE':
   self.status = 1
  else:
   self.status = 2

 def __call__(self):
  return self.status

 def __repr__(self):
  return unicode_to_repr('%s()' % self.__class__.__name__)

# 定义serializer
class GameSerializer(serializers.ModelSerializer):
 class Meta:
  model = Game
  exclude = ['created_time']

 shop = serializers.HiddenField(
  default=CurrentShopDefault()
 )
 status = serializers.HiddenField(
  default=CurrentStatus()
 )

class GameOpView(mixins.CreateModelMixin, mixins.UpdateModelMixin, mixins.RetrieveModelMixin, mixins.DestroyModelMixin, viewsets.GenericViewSet):
 """
  retrieve:
   获取-游戏详情
  create:
   创建-游戏
  update:
   更新-游戏
  delete:
   删除-游戏
  partial_update:
   更新游戏状态
  total_info:
   游戏数据总览
 """
 permission_classes = [IsShop, ]
 pagination_class = StandardResultsSetPagination

 def get_queryset(self):
  return Game.objects.filter(
   Q(shop=self.request.user.shop) | Q(shop__com_circle=self.request.user.shop))

 def get_serializer_class(self):
  if self.action == 'partial_update':
   return GameStatusSerializer
  elif self.action == 'retrieve':
   return GameReadSerializer
  else:
   return GameSerializer

class CurrentUser(object):
 def set_context(self, serializer_field):
  self.user_obj = serializer_field.context['request'].user

 def __call__(self):
  return self.user_obj

class GetObjectFlow(object):
 def set_context(self, serializer_field):
  self.object_flow = serializer_field.context['request'].data.get('object_flow') # 这里需要在views中传进去呀，djangocontext上下文中才能取到

 def __call__(self):
  return self.object_flow


class AddHolidaySerializer(serializers.ModelSerializer, BaseModelSerializer):
 user = serializers.HiddenField(default=CurrentUser()) # 给用户外键赋当前请求的user
 object_flow = serializers.HiddenField(default=GetObjectFlow()) # 后端自己处理一些特殊的外键
 status = serializers.HiddenField(default=0) # 默认新增时给status赋初值

 class Meta:
  model = Holiday
  exclude = ('deleted',)