restful-framwork续集
作者：互联网
1.DRF的视图
1.1APIView与View的区别
我们django中写CBV的时候继承的是View，rest_framework继承的是APIView，那么他们两个有什么不同呢~~~
urlpatterns = [
url(r'^book$', BookView.as_view()),
url(r'^book/(?P<id>\d+)$', BookEditView.as_view()),
]
我们可以看到，不管是View还是APIView最开始调用的都是as_view()方法~~那我们走进源码看看~~
我们能看到，APIView继承了View, 并且执行了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的认证。
那我们看看View中的as_view()方法做了什么~
我们看到了~在View中的as_view方法返回了view函数，而view函数执行了self.dispatch()方法~~但是这里的dispatch方法应该是我们APIView中的~~
我们去initialize_request中看下把什么赋值给了request，并且赋值给了self.request, 也就是我们在视图中用的request.xxx到底是什么~~
我们看到，这个方法返回的是Request这个类的实例对象~~我们注意我们看下这个Request类中的第一个参数request，是我们走我们django的时候的原来的request~
我们看到了，这个Request类把原来的request赋值给了self._request, 也就是说以后_request是我们老的request，新的request是我们这个Request类~~
那我们继承APIView之后请求来的数据都在哪呢~~
我们用了rest_framework框架以后，我们的request是重新封装的Request类~
request.query_params 存放的是我们get请求的参数
request.data 存放的是我们所有的数据，包括post请求的以及put，patch请求~~~
相比原来的django的request，我们现在的request更加精简，清晰了~~~
现在我们知道了APIView和View的一些区别~~当然还有~~后面我们还会说~~
我们写的视图可能对多个表进行增删改查，就导致我们的视图特别多重复的代码~~
那么我们尝试着来进行封装一下~~1.2第一次封装
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, 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("删除的书籍不存在")# 第一次封装
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(object):
def list(self, request, *args, **kwargs):
queryset = self.get_queryset()
serializer = self.get_serializer(queryset, many=True)
return Response(serializer.data)
class CreateModelMixin(object):
def create(self, request, *args, **kwargs):
serializer = self.get_serializer(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.validated_data)
else:
return Response(serializer.errors)
class RetrieveModelMixin(object):
def retrieve(self, request, id, *args, **kwargs):
book_obj = self.get_queryset().filter(pk=id).first()
book_ser = self.get_serializer(book_obj)
return Response(book_ser.data)
class UpdateModelMixin(object):
def update(self, request, id, *args, **kwargs):
book_obj = self.get_queryset().filter(pk=id).first()
book_ser = self.get_serializer(book_obj, 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)
class DestroyModelMixin(object):
def destroy(self, request, id, *args, **kwargs):
queryset = self.get_queryset()
try:
queryset.get(pk=id).delete()
return Response("")
except Exception as e:
return Response("信息有误")
# 我们把公共的部分抽出来 这样不管写多少表的增删改查都变的很简单
# 这样封装后我们的视图会变成这样
class BookView(GenericAPIView, ListModelMixin, CreateModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
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 BookEditView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
def 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 destroy(self, request, id, *args, **kwargs):
return self.delete(request, id, *args, **kwargs)
我们封装的GenericAPIView，包括封装每个方法的类，其实框架都帮我们封装好了~~
我们可以直接继承这些类~~来实现上面的视图~~可是还有没有更简单的方法呢~我们再次封装一下~~1.3二次封装
# 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 BookView(ListCreateAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
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 BookEditView(RetrieveUpdateDestroyAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
def 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)这次我们只是让继承变的简单了一点而已，好像并没有什么大的进步~~
我们可不可以把这两个视图合并成一个视图呢~~~框架给我们提供了一个路由传参的方法~~
我们看下ViewSetMixin
actions这个默认参数其实就是我们路由可以进行传参了~~~
下面这个循环~可以看出~我们要传的参数是一个字段~key应该是我们的请求方式，value应该对应我们处理的方法~
这样我们每个视图就不用在写函数了~因为已经和内部实现的函数相对应了~1.4三次封装
#urls.py
urlpatterns = [
# url(r'^book$', BookView.as_view()),
# url(r'^book/(?P<id>\d+)$', BookEditView.as_view()),
url(r'^book$', BookView.as_view({"get": "list", "post": "create"})),
url(r'^book/(?P<pk>\d+)$', BookView.as_view({"get": "retrieve", "patch": "update", "delete": "destroy"})),
]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, RetrieveUpdateDestroyAPIView):
pass
class BookView(ModelViewSet):
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~
注意一点~~
用框架封装的视图~我们url上的那个关键字参数要用pk~~系统默认的~~
奉献一张图来看下我们的继承顺序~~~
2.DRF的路由
from django.contrib import admin
from django.urls import path,include
from app.views import BookView
from rest_framework.routers import DefaultRouter
router = DefaultRouter()
router.register(r"book", BookView)
urlpatterns = [
path('admin/', admin.site.urls),
# path(r'book/', BookView.as_view({"get": "list", "post": "create"})),
# path('book/<int:pk>/', BookView.as_view({"get": "list", "put": "update", "delete": "destroy"})),
]
urlpatterns += router.urls
我们可以看到~~通过框架我们可以把路由视图都变的非常简单~~
但是需要自定制的时候还是需要我们自己用APIView写~~当不需要那么多路由的时候~也不要用这种路由注册~~3.案例展示
#views.py
from app.models import Book, Publisher
from rest_framework.viewsets import ModelViewSet
from app.serializers import BookSerializer
class BookView(ModelViewSet):
queryset = Book.objects.all()
serializer_class = BookSerializer#urls.py
from django.contrib import admin
from django.urls import path,include
from app.views import BookView
from rest_framework.routers import DefaultRouter
router = DefaultRouter()
router.register(r"book", BookView)
urlpatterns = [
path('admin/', admin.site.urls),
# path(r'book/', BookView.as_view({"get": "list", "post": "create"})),
# path('book/<int:pk>/', BookView.as_view({"get": "list", "put": "update", "delete": "destroy"})),
]
urlpatterns += router.urls
#自定制的urls.py
默认的urls配置，暴露了过多的方法，有的时候，我们不想暴露put或delete，就需要自定制url
from django.contrib import admin
from django.urls import path,include
from app.views import BookView
from rest_framework.routers import DefaultRouter
router = DefaultRouter()
urlpatterns = [
path('admin/', admin.site.urls),
path(r'book/', BookView.as_view({"get": "list", "post": "create"})),
#注意get对应retrive,只获取一条数据
#不希望有delete,就去掉delete即可。
path('book/<int:pk>/', BookView.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})),
]
标签：续集,return,get,self,args,request,framwork,book,restful 来源： https://blog.51cto.com/10983441/2435035