我们知道，DRF视图体系，封装程度最高的是ModelViewSet，它集增删改查的mixins与GenericViewSet于一体。
class ModelViewSet(mixins.CreateModelMixin,
mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
mixins.ListModelMixin,
GenericViewSet):
pass所以，业务视图类只要继承它就能实现增删改查的功能，然而，正是由于它的抽象性太高，一些定制化的功能无法实现，所以大多数情况下，我们选择重写ModelViewSet，但ModelViewSet又只是一个空壳，重写他就是重写他集成的类的功能，这里我们先重写这些mixins。
CreateModelMixin
代码语言：Python复制class CreateModelMixin:
"""
Create a model instance.
"""
def create(self, request, *args, **kwargs):
if not isinstance(request.user, AnonymousUser):
request.data['created_by'] = request.user.get('id')
request.data['updated_by'] = request.user.get('id')
serializer = self.get_serializer(data=request.data)
serializer.is_valid(raise_exception=True)
self.perform_create(serializer)
headers = self.get_success_headers(serializer.data)
return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)
def perform_create(self, serializer):
try:
with transaction.atomic():
serializer.save()
except Exception as e:
raise ValidationError({'msg': str(e)})
def get_success_headers(self, data):
try:
return {'Location': str(data[api_settings.URL_FIELD_NAME])}
except (TypeError, KeyError):
return {}增加功能：
- 新建数据时，为
created_by赋值当前请求发送者信息 - 新建数据时，为
updated_by赋值当前请求发送者信息
ListModelMixin
代码语言：Python复制class ListModelMixin:
"""
List a queryset.
"""
def list(self, request, *args, **kwargs):
use_pagination = request.query_params.get('use_pagination', True) # 如果禁用分页，传参use_pagination=False
queryset = self.filter_queryset(self.get_queryset())
if use_pagination:
page = self.paginate_queryset(queryset)
if page is not None:
serializer = self.get_serializer(page, many=True)
return self.get_paginated_response(serializer.data)
serializer = self.get_serializer(queryset, many=True)
return Response(serializer.data)增加功能：
- URL查询参数增加
use_pagination查询，用于控制是否启用分页
UpdateModelMixin
代码语言：Python复制class UpdateModelMixin:
"""
Update a model instance.
"""
def update(self, request, *args, **kwargs):
partial = kwargs.pop('partial', False)
if not isinstance(request.user, AnonymousUser):
request.data['updated_by'] = request.user.get('id')
instance = self.get_object()
serializer = self.get_serializer(instance, data=request.data, partial=partial)
serializer.is_valid(raise_exception=True)
self.perform_update(serializer)
if getattr(instance, '_prefetched_objects_cache', None):
# If 'prefetch_related' has been applied to a queryset, we need to
# forcibly invalidate the prefetch cache on the instance.
instance._prefetched_objects_cache = {}
return Response(serializer.data)
def perform_update(self, serializer):
try:
with transaction.atomic():
serializer.save()
except Exception as e:
raise ValidationError({'msg': str(e)})
def partial_update(self, request, *args, **kwargs):
kwargs['partial'] = True
return self.update(request, *args, **kwargs)- 更新数据时，为
updated_by赋值当前请求发送者信息
DestroyModelMixin
代码语言：Python复制class DestroyModelMixin:
"""
Destroy a model instance.
"""
def destroy(self, request, *args, **kwargs):
instance = self.get_object()
self.perform_destroy(instance)
return Response(status=status.HTTP_204_NO_CONTENT)
def perform_destroy(self, instance):
# 逻辑删除
filter_active = getattr(self, 'filter_active', True)
try:
with transaction.atomic():
if filter_active:
instance.is_deleted = True
instance.save()
else:
instance.delete()
except Exception as e:
raise ValidationError({'msg': str(e)})- 删除时，按照视图类是否有配置
filter_active属性控制其是否是软删除
