自学教程：DRF之请求与响应的实现

# 请求对象# from rest_framework.request import Request    def __init__(self, request, parsers=None, authenticators=None,                 negotiator=None, parser_context=None):        # 二次封装request，将原生request作为drf request对象的 _request 属性        self._request = request    def __getattr__（self，item）：     return getattr(self._request,item)# 请求对象.data:前端以三种编码方式传入的数据，都可以取出来# 请求对象..query_params 与Django标准的request.GET相同，只是更换了更正确的名称而已。

#from rest_framework.response import Response def __init__(self, data=None, status=None,                 template_name=None, headers=None,                 exception=False, content_type=None):        #data：你要返回的数据，字典#status：返回的状态码，默认是200， -from rest_framework import status在这个路径下，它把所有使用到的状态码都定义成了常量#template_name 渲染的模板名字（自定制模板），不需要了解#headers:响应头，可以往响应头放东西，就是一个字典#content_type：响应的编码格式，application/json和text/html;# 浏览器响应成浏览器的格式，postman响应成json格式，通过配置实现的（默认配置）#不管是postman还是浏览器，都返回json格式数据# drf有默认的配置文件---》先从项目的setting中找，找不到，采用默认的# drf的配置信息，先从自己类中找--》项目的setting中找---》默认的找 -局部使用:对某个视图类有效        -在视图类中写如下        from rest_framework.renderers import JSONRenderer        renderer_classes=[JSONRenderer,]    -全局使用：全局的视图类，所有请求，都有效     -在setting.py中加入如下        REST_FRAMEWORK = {            'DEFAULT_RENDERER_CLASSES': (  # 默认响应渲染类                'rest_framework.renderers.JSONRenderer',  # json渲染器                'rest_framework.renderers.BrowsableAPIRenderer',  # 浏览API渲染器            )        }

# 两个视图基类APIViewGenericAPIView

#### views.pyfrom rest_framework.generics import GenericAPIViewfrom app01.models import Bookfrom app01.ser import BookSerializer# 基于APIView写的class BookView(APIView):    def get(self,request):        book_list=Book.objects.all()        book_ser=BookSerializer(book_list,many=True)        return Response(book_ser.data)    def post(self,request):        book_ser = BookSerializer(data=request.data)        if book_ser.is_valid():            book_ser.save()            return Response(book_ser.data)        else:            return Response({'status':101,'msg':'校验失败'})class BookDetailView(APIView):    def get(self, request,pk):        book = Book.objects.all().filter(pk=pk).first()        book_ser = BookSerializer(book)        return Response(book_ser.data)    def put(self, request,pk):        book = Book.objects.all().filter(pk=pk).first()        book_ser = BookSerializer(instance=book,data=request.data)        if book_ser.is_valid():            book_ser.save()            return Response(book_ser.data)        else:            return Response({'status': 101, 'msg': '校验失败'})    def delete(self,request,pk):        ret=Book.objects.filter(pk=pk).delete()        return Response({'status': 100, 'msg': '删除成功'})    #models.pyclass Book(models.Model):    name=models.CharField(max_length=32)    price=models.DecimalField(max_digits=5,decimal_places=2)    publish=models.CharField(max_length=32)#ser.pyclass BookSerializer(serializers.ModelSerializer):    class Meta:        model=Book        fields='__all__'# urls.pypath('books/', views.BookView.as_view()),re_path('books/(?P<pk>/d+)', views.BookDetailView.as_view()),

# views.pyclass Book2View(GenericAPIView):    #queryset要传queryset对象，查询了所有的图书    # serializer_class使用哪个序列化类来序列化这堆数据    queryset=Book.objects    # queryset=Book.objects.all()    serializer_class = BookSerializer    def get(self,request):        book_list=self.get_queryset()        book_ser=self.get_serializer(book_list,many=True)        return Response(book_ser.data)    def post(self,request):        book_ser = self.get_serializer(data=request.data)        if book_ser.is_valid():            book_ser.save()            return Response(book_ser.data)        else:            return Response({'status':101,'msg':'校验失败'})class Book2DetailView(GenericAPIView):    queryset = Book.objects    serializer_class = BookSerializer    def get(self, request,pk):        book = self.get_object()        book_ser = self.get_serializer(book)        return Response(book_ser.data)    def put(self, request,pk):        book = self.get_object()        book_ser = self.get_serializer(instance=book,data=request.data)        if book_ser.is_valid():            book_ser.save()            return Response(book_ser.data)        else:            return Response({'status': 101, 'msg': '校验失败'})    def delete(self,request,pk):        ret=self.get_object().delete()        return Response({'status': 100, 'msg': '删除成功'})     #url.py    # 使用GenericAPIView重写的    path('books2/', views.Book2View.as_view()),    re_path('books2/(?P<pk>/d+)', views.Book2DetailView.as_view()),

from rest_framework.mixins import  ListModelMixin,CreateModelMixin,UpdateModelMixin,DestroyModelMixin,RetrieveModelMixin# views.pyclass Book3View(GenericAPIView,ListModelMixin,CreateModelMixin):    queryset=Book.objects    serializer_class = BookSerializer    def get(self,request):        return self.list(request)    def post(self,request):        return self.create(request)class Book3DetailView(GenericAPIView,RetrieveModelMixin,DestroyModelMixin,UpdateModelMixin):    queryset = Book.objects    serializer_class = BookSerializer    def get(self, request,pk):        return self.retrieve(request,pk)    def put(self, request,pk):        return self.update(request,pk)    def delete(self,request,pk):        return self.destroy(request,pk)# urls.py    # 使用GenericAPIView+5 个视图扩展类  重写的    path('books3/', views.Book3View.as_view()),    re_path('books3/(?P<pk>/d+)', views.Book3DetailView.as_view()),

# views.pyfrom rest_framework.viewsets import ModelViewSetclass Book5View(ModelViewSet):  #5个接口都有，但是路由有点问题    queryset = Book.objects    serializer_class = BookSerializer    # urls.py# 使用ModelViewSet编写5个接口    path('books5/', views.Book5View.as_view(actions={'get':'list','post':'create'})), #当路径匹配，又是get请求，会执行Book5View的list方法    re_path('books5/(?P<pk>/d+)', views.Book5View.as_view(actions={'get':'retrieve','put':'update','delete':'destroy'})),

# 重写了as_view# 核心代码（所以路由中只要配置了对应关系，比如{'get':'list'}）,当get请求来，就会执行list方法for method, action in actions.items():    #method：get    # action：list    handler = getattr(self, action)    #执行完上一句，handler就变成了list的内存地址    setattr(self, method, handler)    #执行完上一句  对象.get=list    #for循环执行完毕 对象.get:对着list   对象.post：对着create

# views.pyfrom rest_framework.viewsets import ViewSetMixinclass Book6View(ViewSetMixin,APIView): #一定要放在APIVIew前    def get_all_book(self,request):        print("xxxx")        book_list = Book.objects.all()        book_ser = BookSerializer(book_list, many=True)        return Response(book_ser.data)    # urls.py    #继承ViewSetMixin的视图类，路由可以改写成这样    path('books6/', views.Book6View.as_view(actions={'get': 'get_all_book'})),