drf中View和router的详解
Rest Framework 视图和路由
因为涉及到视图层面了,而且下面的例子会反复用到request.data,所以我决定带大家稍微看下源码,感兴趣的可以自己深入了解
无论是View还是APIView最开始都是调用as_view()
大致过了下APIView给我们封装的数据
总结一下
- 旧的request封装到新request属性_request里
- 继承APIView,重新封装的request.query_params相当于旧的request.GET
- request.data相当于旧的request.POST和request.FILES,且支持json数据类型
第一版封装
app/views
class BookView(APIView):
def get(self, request):
query_set = Book.objects.all()
book_ser = BookSerializer(query_set, many=True)
return Response(book_ser.data)
def post(self, request):
query_set = request.data
book_ser = BookSerializer(data=query_set)
if book_ser.is_valid():
book_ser.save()
return Response(book_ser.validated_data)
else:
return Response(book_ser.errors)
class BookEditView(APIView):
def get(self, request, pk):
query_set = Book.objects.filter(pk=pk).first()
book_ser = BookSerializer(query_set)
return Response(book_ser.data)
def patch(self, request, pk):
query_set = Book.objects.filter(pk=pk).first()
book_ser = BookSerializer(query_set, data=request.data, partial=True)
if book_ser.is_valid():
book_ser.save()
return Response(book_ser.validated_data)
else:
return Response(book_ser.errors)
def delete(self, request, pk):
query_set = Book.objects.filter(pk=pk).first()
if query_set:
query_set.delete()
return Response("")
else:
return Response("删除的书籍不存在")
使用Mixin封装方法
class GenericAPIView(APIView):
queryset = None
serializer_class = None
def get_queryset(self):
return self.queryset.all()
def get_serializer(self,*args,**kwargs):
return self.serializer_class(*args,**kwargs)
class ListModelMixin:
def list(self,request,*args,**kwargs):
queryset = self.get_queryset()
book_sel = self.get_serializer(queryset,many=True)
return Response(book_sel.data)
class CreateModelMixin:
def create(self,request,*args,**kwargs):
book_sel = self.serializer_class(data=request.data)
if book_sel.is_valid():
book_sel.save()
return Response(book_sel.data)
else:
return Response(book_sel.errors)
class UpdateModelMixin:
def update(self,request,pk,*args,**kwargs):
book_obj = self.get_queryset().filter(pk=pk).first()
book_sel = self.serializer_class(book_obj,data=request.data,partial=True)
if book_sel.is_valid():
book_sel.save()
return Response(book_sel.data)
else:
return Response(book_sel.errors)
class RetrieveModelMixin:
def retrieve(self,request,pk,*args,**kwargs):
book_obj = self.get_queryset().filter(pk=pk).first()
book_sel = self.serializer_class(book_obj)
return Response(book_sel.data)
class DestroyModelMixin:
def destroy(self, request, pk, *args, **kwargs):
queryset = self.get_queryset()
try:
queryset.get(pk=pk).delete()
return Response("")
except Exception as e:
return Response("信息有误")
# Create your views here.
class BookEditView(GenericAPIView,RetrieveModelMixin,UpdateModelMixin,DestroyModelMixin):
queryset = models.Book.objects
serializer_class = BookSerializers
def get(self,request,pk,*args,**kwargs):
return self.retrieve(request,pk,*args,**kwargs)
def patch(self,request,pk,*args,**kwargs):
return self.update(request,pk,*args,**kwargs)
def delete(self,request,pk,*args,**kwargs):
return self.destroy(request,pk,*args,**kwargs)
class BookView(GenericAPIView,ListModelMixin,CreateModelMixin):
queryset = models.Book.objects
serializer_class = BookSerializers
def get(self,request,*args,**kwargs):
return self.list(request,*args,**kwargs)
def post(self,request,*args,**kwargs):
return self.create(request,*args,**kwargs)
# 技术点:因为drf中的GenericAPIView提供了queryset和serializer_class,如果要继承GenericAPIView,
# 则必须重写这两个字段,且GenericAPIView提供get_queryset和get_serializer两个方法
# Mixin类不用继承其他API,只是单独提供方法接口,必须跟其他API类混合继承
感觉经过这么一封装,每个类中的方法看起来清爽多了,我们还可以继续封装
第二版封装
# 上面我们写的继承类太长了~~我们再改改
class ListCreateAPIView(GenericAPIView, ListModelMixin, CreateModelMixin):
pass
class RetrieveUpdateDestroyAPIView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
pass
class BookEditView(RetrieveUpdateDestroyAPIView):
queryset = models.Book.objects
serializer_class = BookSerializers
def get(self,request,pk,*args,**kwargs):
return self.retrieve(request,pk,*args,**kwargs)
def patch(self,request,pk,*args,**kwargs):
return self.update(request,pk,*args,**kwargs)
def delete(self,request,pk,*args,**kwargs):
return self.destroy(request,pk,*args,**kwargs)
class BookView(ListCreateAPIView):
queryset = models.Book.objects
serializer_class = BookSerializers
def get(self,request,*args,**kwargs):
return self.list(request,*args,**kwargs)
def post(self,request,*args,**kwargs):
return self.create(request,*args,**kwargs)
感觉只是把类中的继承稍微简化了下,并不是特别的优雅,来康康第三版
第三版封装
我们知道,一般的View执行as_view()不能传入参数,接下来要介绍的ViewSetMixin,重写了as_view(actions),可以传入我们需要的参数
urlpatterns = [
url(r'^book$', BookView.as_view({"get": "list", "post": "create"})),
url(r'^retrieve/(?P<pk>\d+)$', BookEditView.as_view({"get": "retrieve", "patch": "update", "delete": "destroy"})), //这里要注意的是,使用这种传参的view,传入的动态id要命名为pk
]
urls.py
from rest_framework.viewsets import ViewSetMixin
# class BookView(ViewSetMixin, ListCreateAPIView, RetrieveUpdateDestroyAPIView):
# queryset = Book.objects.all()
# serializer_class = BookSerializer
# 如果我们再定义一个类
class ModelViewSet(ViewSetMixin, ListCreateAPIView):
pass
class OwnViewSet(ViewSetMixin,RetrieveUpdateDestroyAPIView)
class BookView(ModelViewSet):
queryset = Book.objects.all()
serializer_class = BookSerializer
class BookEditView(OwnViewSet):
queryset = Book.objects.all()
serializer_class = BookSerializer
我们现在的视图就只要写两行就可以了,其实我们写的所有的视图~框架都帮我们封装好了,刚刚上面用的例子都是手动封装
奉献一张图来看下我们的继承顺序~~~
drf的路由
我们上面的路由传参写的特别多~~框架也帮我们封装好了~
from rest_framework.routers import DefaultRouter
router = DefaultRouter()
router.register(r"book", BookView)
urlpatterns = [
]
urlpatterns += router.urls
通过框架的路由可以看出,手写的代码几乎没有了,这里提出一点建议,如果自己的业务逻辑不是跟增删改查特别耦合
不建议用drf提供的路由组件,因为这样会暴露很多的接口,不太安全,总之,一般我们很少用到这个组件,还是尽量自己手写
总结
类的继承链越高,所拥有的功能也就越少,可定制化的程度就越高,尽管上面我们用底层的类,特别轻松的实现了功能,
但需要自定制时,还是继承APIView实现自己的业务逻辑,总之一切按照业务逻辑来走
