drf4 视图与路由组件
APIView和View的區別
不管是View還是APIView最開始調用的都是as_view()
APIView繼承了View, 并且執行了View中的as_view()方法,最后把view返回了,用csrf_exempt()方法包裹后去掉了csrf的認證。
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在View中的as_view方法返回了view函數,而view函數執行了self.dispatch()方法,但是這里的dispatch方法應該是我們APIView中的
去initialize_request中看下把什么賦值給了request,并且賦值給了self.request, 也就是我們在視圖中用的request.xxx到底是什么~~
看到,這個方法返回的是Request這個類的實例對象~~我們注意我們看下這個Request類中的第一個參數request,是我們走我們django的時候的原來的request
我們看到了,這個Request類把原來的request賦值給了self._request, 也就是說以后_request是我們老的request,新的request是我們這個Request類
我們用了rest_framework框架以后,我們的request是重新封裝的Request類
request.query_params 存放的是我們get請求的參數
request.data 存放的是我們所有的數據,包括post請求的以及put,patch請求
相比原來的django的request,我們現在的request更加精簡,清晰了
現在我們知道了APIView和View的一些區別
視圖的第一次封裝
GenericAPIView 是對 APIView 的封裝 xxxMixin 是對處理的各種請求方法的封裝 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.databook_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, id):query_set = Book.objects.filter(id=id).first()book_ser = BookSerializer(query_set)return Response(book_ser.data)def patch(self, request, id):query_set = Book.objects.filter(id=id).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, id):query_set = Book.objects.filter(id=id).first()if query_set:query_set.delete()return Response("")else:return Response("刪除的書籍不存在")APIView視圖 APIView from rest_framework.views import APIView from rest_framework.viewsets import GenericViewSet from rest_framework.response import Response from .serializers import BookSerializerclass GenericAPIView(APIView):query_set = Noneserializer_class = Nonedef get_queryset(self):return self.query_setdef get_serializer(self, *args, **kwargs):return self.serializer_class(*args, **kwargs)class ListModelMixin(object):def list(self, request):queryset = self.get_queryset()ret = self.get_serializer(queryset, many=True)return Response(ret.data)class CreateModelMixin(object):def create(self, request):serializer = self.get_serializer(data=request.data)if serializer.is_valid():serializer.save()return Response(serializer.data)else:return Response(serializer.errors)class RetrieveModelMixin(object):def retrieve(self, request, id):book_obj = self.get_queryset().filter(id=id).first()ret = self.get_serializer(book_obj)return Response(ret.data)class UpdateModelMixin(object):def update(self, request, id):book_obj = self.get_queryset().filter(id=id).first()serializer = self.get_serializer(book_obj, data=request.data, partial=True)if serializer.is_valid():serializer.save()return Response(serializer.data)else:return Response(serializer.errors)class DestroyModelMixin(object):def destroy(self, request, id):book_obj = self.get_queryset().filter(id=id).first()book_obj.delete()return Response("")class ListCreateAPIView(GenericAPIView, ListModelMixin, CreateModelMixin):passclass RetrieveUpdateDestroyAPIView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):pass# class BookView(GenericAPIView, ListModelMixin, CreateModelMixin): class BookView(ListCreateAPIView):query_set = Book.objects.all() # 操作的表的對象serializer_class = BookSerializer # 序列化的類def get(self, request):# book_obj = Book.objects.first()# ret = BookSerializer(book_obj)# book_list = Book.objects.all()# book_list = self.get_queryset()# ret = self.get_serializer(book_list, many=True)# return Response(ret.data)return self.list(request)def post(self, request):# print(request.data)# serializer = BookSerializer(data=request.data)# if serializer.is_valid():# serializer.save()# return Response(serializer.data)# else:# return Response(serializer.errors)return self.create(request)# class BookEditView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin): class BookEditView(RetrieveUpdateDestroyAPIView):query_set = Book.objects.all()serializer_class = BookSerializerdef get(self, request, id):# book_obj = Book.objects.filter(id=id).first()# ret = BookSerializer(book_obj)# return Response(ret.data)return self.retrieve(request, id)def put(self, request, id):# book_obj = Book.objects.filter(id=id).first()# serializer = BookSerializer(book_obj, data=request.data, partial=True)# if serializer.is_valid():# serializer.save()# return Response(serializer.data)# else:# return Response(serializer.errors)return self.update(request, id)def delete(self, request, id):# book_obj = Book.objects.filter(id=id).first()# book_obj.delete()# return Response("")return self.destroy(request, id) 視圖的第一次封裝視圖的第二次封裝
class ListCreateAPIView(GenericAPIView, ListModelMixin, CreateModelMixin):passclass RetrieveUpdateDestroyAPIView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):passclass BookView(ListCreateAPIView):passclass BookEditView(RetrieveUpdateDestroyAPIView):pass # 上面我們寫的繼承類太長了~~我們再改改class ListCreateAPIView(GenericAPIView, ListModelMixin, CreateModelMixin):passclass RetrieveUpdateDestroyAPIView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):passclass BookView(ListCreateAPIView):queryset = Book.objects.all()serializer_class = BookSerializerdef get(self, request, *args, **kwargs):return self.list(request, *args, **kwargs)def post(self, request, *args, **kwargs):return self.create(request, *args, **kwargs)class BookEditView(RetrieveUpdateDestroyAPIView):queryset = Book.objects.all()serializer_class = BookSerializerdef get(self, request, id, *args, **kwargs):return self.retrieve(request, id, *args, **kwargs)def patch(self, request, id, *args, **kwargs):return self.update(request, id, *args, **kwargs)def delete(self, request, id, *args, **kwargs):return self.delete(request, id, *args, **kwargs)第二次封裝 第二次封裝視圖的第三次封裝
ViewSetMixin
actions這個默認參數其實就是我們路由可以進行傳參了
下面這個循環,可以看出,我們要傳的參數是一個字段~key應該是我們的請求方式,value應該對應我們處理的方法
這樣我們每個視圖就不用在寫函數了,因為已經和內部實現的函數相對應了
因為是按照請求的方式不同反回的結果,所有第二次有兩個視圖函數
現在指定一個視圖函數
# 視圖類傳參,不同的請求對應不同的方法path('list', BookModelViewSet.as_view({"get": "list", "post": "create"})),path('retrieve/<int:pk>', BookModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})),注意一點,用框架封裝的視圖,我們url上的那個關鍵字參數要用pk,系統默認的
# class ViewSetMixin(object): # def as_view(self): # """ # 按照我們參數指定的去匹配 對應的方法 # get-->list # :return: 不用我們去寫,框架有 # """ViewSetMixin 請求分發方法的原理,將不同的請求設置為不同的方法
from rest_framework.viewsets import ViewSetMixin# class BookView(ViewSetMixin, ListCreateAPIView, RetrieveUpdateDestroyAPIView): # queryset = Book.objects.all() # serializer_class = BookSerializer# 如果我們再定義一個類 class ModelViewSet(ViewSetMixin, ListCreateAPIView, RetrieveUpdateDestroyAPIView):passclass BookView(ModelViewSet):queryset = Book.objects.all()serializer_class = BookSerializer第三次封裝 第三次封裝 from rest_framework.viewsets import ViewSetMixinclass ModelViewSet(ViewSetMixin, GenericAPIView, ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):pass# from rest_framework.viewsets import ModelViewSet # 框架內部已經實現了的,可以直接導入 # class BookModelViewSet(ModelViewSet): query_set = Book.objects.all() 自己封裝的query_set? # queryset = Book.objects.all() # 框架的是queryset
serializer_class = BookSerializer from rest_framework import views # APIView
from rest_framework import generics # GenericAPIView, 組合類
from rest_framework import mixins #混合繼承類
from rest_framework import viewsets # ViewSetMixin 分發請求的類
我們現在的視圖就只要寫兩行就可以了
用框架的時
路由為
path('retrieve/<int:pk>', BookModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})),前面自己定義的是id,用框架時注意修改過來
path('retrieve/<int:id>', BookModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})), # 視圖類傳參.只有業務需求匹配性很強才用。通常情況下不這么用容易暴露接口# path('list', BookModelViewSet.as_view({"get": "list", "post": "create"})),# path('retrieve/<int:id>', BookModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})),繼承順序
DRF的路由
from django.urls import path, include from .views import BookView, BookEditView, BookModelViewSet from rest_framework.routers import DefaultRouterrouter = DefaultRouter()router.register(r"", BookModelViewSet) # 不能 加$ r"$"urlpatterns = [# path('list', BookView.as_view()),# path('retrieve/<int:id>', BookEditView.as_view()),# 視圖類傳參.只有業務需求匹配性很強才用。通常情況下不這么用容易暴露接口# path('list', BookModelViewSet.as_view({"get": "list", "post": "create"})),# path('retrieve/<int:id>', BookModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})),]urlpatterns += router.urlsDefaultRouter DRF的路由通過框架我們可以把路由視圖都變的非常簡單,但是需要自定制的時候還是需要我們自己用APIView寫
當不需要那么多路由的時候,也不要用這種路由注冊
總之,一切按照業務需要去用
總結
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