Django框架（二十四）—— Django rest_framework-视图组件
视图组件
一、基本视图
class PublishView(APIView):
def get(self, request):
publish_list = Publish.objects.all()
bs = PublishSerializers(publish_list, many=True)
return JsonResponse(bs.data,safe=False)
def post(self, request):
# 添加一条数据
print(request.data)
bs = PublishSerializers(data=request.data)
if bs.is_valid():
bs.save() # 生成记录
return JsonResponse(bs.data,safe=False)
else:
return JsonResponse(bs.errors,safe=False)
class PublishDetailView(APIView):
def get(self, request, pk):
publish_obj = Publish.objects.filter(pk=pk).first()
bs = PublishSerializers(publish_obj, many=False)
return JsonResponse(bs.data,safe=False)
def put(self, request, pk):
publish_obj = Publish.objects.filter(pk=pk).first()
bs = PublishSerializers(data=request.data, instance=publish_obj)
if bs.is_valid():
bs.save() # update
return JsonResponse(bs.data)
else:
return JsonResponse(bs.errors)
def delete(self, request, pk):
Publish.objects.filter(pk=pk).delete()
return JsonResponse("")二、自定义的封装视图
class Create:
def create(self,request):
bs = serializers(data=request.data)
if bs.is_valid():
bs.save() # 生成记录
return JsonResponse(bs.data,safe=False)
else:
return JsonResponse(bs.errors,safe=False)
class List:
def list(self,request):
queryset = self.queryset
bs = self.serializers(queryset, many=True)
return JsonResponse(bs.data,safe=False)
# 将create和 list方法抽出来，封装起来
class PublishView(APIView,List,Create):
queryset=Publish.objects.all()
serializers=PublishSerializers
def get(self, request):
return self.list(request)
def post(self, request):
return self.create(request)
class BookView(APIView,List,Create):
queryset=Book.objects.all()
serializers=BookSerializer
def get(self, request):
return self.list(request)
def post(self, request):
return self.create(request)
三、利用mixin类和generice类编写视图
1、使用
# ListModelMixin 查询所有； CreateModelMixin：创建数据； RetrieveModelMixin：查询一条； UpdateModelMixin：更新数据； DestroyModelMixin：删除数据
from rest_framework.mixins import ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin
from rest_framework.generics import GenericAPIView
class PublishView(GenericAPIView,ListModelMixin,CreateModelMixin):
queryset = Publish.objects.all()
serializer_class = PublishSerializers
def get(self, request):
# self.list(request)，ListModelMixin类中的函数属性
return self.list(request)
def post(self, request):
return self.create(request)
class BookView(GenericAPIView,ListModelMixin,CreateModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializers
def get(self, request):
return self.list(request)
def post(self, request):
return self.create(request)
2、源码
（1）ListModelMixin类
class ListModelMixin(object):
def list(self, request, *args, **kwargs):
# 获取queryset对象，filter_queryset是利用过滤条件过滤
queryset = self.filter_queryset(self.get_queryset())
# 分页相关
page = self.paginate_queryset(queryset)
if page is not None:
serializer = self.get_serializer(page, many=True)
return self.get_paginated_response(serializer.data)
# 获取序列化对象
serializer = self.get_serializer(queryset, many=True)
return Response(serializer.data)（2）self.get_queryset()与self.get_serializer()
# self.get_queryset()
# 先自身找，然后类中找，再去父类GenericAPIView中找，找到
def get_queryset(self):
# queryset在GenericAPIView设默认值为None，因此要重新定义queryset，指定queryset对象
queryset = self.queryset
if isinstance(queryset, QuerySet):
# 查询所有数据
queryset = queryset.all()
return queryset
# self.get_serializer()
# 先自身找，然后类中找，再去父类GenericAPIView中找，找到
def get_serializer(self, *args, **kwargs):
# get_serializer_class()返回的是serializer_class，默认值为None，所以要重新定义返回的是serializer_class
serializer_class = self.get_serializer_class()
kwargs['context'] = self.get_serializer_context()
return serializer_class(*args, **kwargs)
（3）CreateModelMixin类下的create
class CreateModelMixin(object):
def create(self, request, *args, **kwargs):
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):
serializer.save()（4）UpdateModelMixin类下的update
class UpdateModelMixin(object):
def update(self, request, *args, **kwargs):
partial = kwargs.pop('partial', False)
# get_object 返回的是一个普通对象
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):
instance._prefetched_objects_cache = {}
return Response(serializer.data)
def perform_update(self, serializer):
serializer.save()
（5）DestroyModelMixin类下的destroy
class DestroyModelMixin(object):
def destroy(self, request, *args, **kwargs):
# get_object 返回的是一个普通对象
instance = self.get_object()
self.perform_destroy(instance)
return Response(status=status.HTTP_204_NO_CONTENT)
def perform_destroy(self, instance):
instance.delete()
（6）RetrieveModelMixin类下的retrieve
class RetrieveModelMixin(object):
#
def retrieve(self, request, *args, **kwargs):
# get_object 返回的是一个普通对象
instance = self.get_object()
serializer = self.get_serializer(instance)
return Response(serializer.data)四、利用generics 下的ListCreateAPIView，RetrieveUpdateDestroyAPIView
1、使用
from rest_framework.generics import ListCreateAPIView, ListAPIView, RetrieveUpdateDestroyAPIView
# 继承了ListCreateAPIView类，而ListCreateAPIView又继承了多个类，并且定义了get和post方法，因此，只需要重定义queryset和serializer_class即可
class PublishView(ListCreateAPIView):
queryset = Publish.objects.all()
serializer_class = PublishSerializers
class PublishDetailView(RetrieveUpdateDestroyAPIView):
queryset = Publish.objects.all()
serializer_class = PublishSerializers2、源码
# 继承了多个类，类中的方法也是调用了GenericAPIView类中的list、create函数属性
class ListCreateAPIView(mixins.ListModelMixin,
mixins.CreateModelMixin,
GenericAPIView):
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
return self.create(request, *args, **kwargs)
class RetrieveUpdateDestroyAPIView(mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
GenericAPIView):
def get(self, request, *args, **kwargs):
return self.retrieve(request, *args, **kwargs)
def put(self, request, *args, **kwargs):
return self.update(request, *args, **kwargs)
def patch(self, request, *args, **kwargs):
return self.partial_update(request, *args, **kwargs)
def delete(self, request, *args, **kwargs):
return self.destroy(request, *args, **kwargs)
五、使用ModelViewSet（不建议使用）
1、使用
# 路由层
url(r'^publish', views.PublishView.as_view({'get': 'list', 'post': 'create'})),
url(r'^publish/(?P<pk>\d+)', views.PublishView.as_view({'get': 'retrieve', 'put': 'update','delete':'destroy'})),
# 视图层
from rest_framework.views import APIView
from rest_framework.viewsets import ModelViewSet
from rest_framework.renderers import JSONRenderer,BrowsableAPIRenderer
class PublishView(ModelViewSet):
queryset = Publish.objects.all()
serializer_class = PublishSerializers2、源码
class ModelViewSet(mixins.CreateModelMixin,
mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
mixins.ListModelMixin,
GenericViewSet):
pass
class GenericViewSet(ViewSetMixin, generics.GenericAPIView):
pass
# ViewSetMixin是一个魔法类，重写了as_view方法，所以继承该类的时候，一般放前面，否则会调用APIView的as_view方法
class ViewSetMixin(object):
"""
This is the magic.
view = MyViewSet.as_view({'get': 'list', 'post': 'create'})
"""
@classonlymethod
def as_view(cls, actions=None, **initkwargs):
cls.name = None
cls.description = None
cls.suffix = None
cls.detail = None
cls.basename = None
def view(request, *args, **kwargs):
self = cls(**initkwargs)
# actions ---> {'get': 'list', 'post': 'create'}
self.action_map = actions
for method, action in actions.items():
handler = getattr(self, action)
# 将list方法的地址赋给get，create方法的地址赋给post
# 将list绑定给GET，create绑定给POST
setattr(self, method, handler)
if hasattr(self, 'get') and not hasattr(self, 'head'):
self.head = self.get
self.request = request
self.args = args
self.kwargs = kwargs
# And continue as usual
return self.dispatch(request, *args, **kwargs)
# take name and docstring from class
update_wrapper(view, cls, updated=())
update_wrapper(view, cls.dispatch, assigned=())
view.cls = cls
view.initkwargs = initkwargs
view.actions = actions
return csrf_exempt(view)
六、强调：ViewSetMixin魔法类
- ViewSetMixin类重写了
as_view方法，因此为了调用它的as_view方法，在继承的时候，要写在APIView前面
class TestAll(ViewSetMixin,APIView):
pass- ViewSetMixin 类可以实现全部视图函数写在一个类中
# 路由层
[
url(r'^test1/$', views.TestAll.as_view({'get': 'test'})), # 将test视图函数赋给get
url(r'^test2/$', views.TestAll.as_view({'get': 'test2'})),
url(r'^test3/$', views.TestAll.as_view({'get': 'test3'}))
]
# 视图层
class TestAll(ViewSetMixin,APIView):
def test(self,request):
return HttpResponse('test')
def test2(self, request):
return HttpResponse('test2')
def test3(self, request):
return HttpResponse('test3')博客内容仅供参考，部分参考他人优秀博文，仅供学习使用
