教程3-类视图

Rewriting our API using class-based views

使用类视图重写root views，只需要一点点重构。

from django.http import Http404
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status

from .models import Course
from .serializer import CourseSerializer


class CourseList(APIView):
    '''
    list all courses,or create a new course
    '''
    def get(self,request,format=None):
        queryset = Course.objects.all()
        serializer = CourseSerializer(queryset,many=True)
        return Response(serializer.data)

    def post(self,request,format=None):
        serializer = CourseSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data,status=status.HTTP_201_CREATED)
        return Response(serializer.data,status=status.HTTP_400_BAD_REQUEST)

class CourseDetail(APIView):
    '''
    retrieve,update or delete a course isntance
    '''
    def get_object(self,pk):
        try:
            return Course.objects.get(pk=pk)
        except Course.DoesNotExist:
            raise Http404

    def get(self,request,pk,format=None):
        course = self.get_object(pk)
        serializer = CourseSerializer(course)
        return Response(serializer.data)

    def put(self, request, pk, format=None):
        course = self.get_object(pk)
        serializer = CourseSerializer(course, data=request.data)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

    def delete(self, request, pk, format=None):
        course = self.get_object(pk)
        course.delete()
        return Response(status=status.HTTP_204_NO_CONTENT)

　　

urlpatterns = [
    path('admin/', xadmin.site.urls),
    path('course/', views.CourseList.as_view(),name='course_list'),
    path('course/<int:pk>/', views.CourseDetail.as_view() ,name='course_detail'),
]
urlpatterns = format_suffix_patterns(urlpatterns)
#使用类视图的url方法as_view()

　　

Using mixins

使用类视图最大的好处就是可以行为重用

from rest_framework import mixins
from rest_framework import generics

from .models import Course
from .serializer import CourseSerializer

class CourseList(mixins.ListModelMixin,
                  mixins.CreateModelMixin,
                  generics.GenericAPIView):
    queryset = Course.objects.all()
    serializer_class = CourseSerializer

    def get(self, request, *args, **kwargs):
        return self.list(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        return self.create(request, *args, **kwargs)
#使用GenericAPIView建立view，提供核心功能。
#加入ListModelMixin和CreateModelMixin，提供.list()和.create()动作。
#然后把get和post方法绑定到相关动作上。


class CourseDetail(mixins.RetrieveModelMixin,
                    mixins.UpdateModelMixin,
                    mixins.DestroyModelMixin,
                    generics.GenericAPIView):
    queryset = Course.objects.all()
    serializer_class = CourseSerializer

    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 delete(self, request, *args, **kwargs):
        return self.destroy(request, *args, **kwargs
#再次使用GenericAPIView提供核心功能，然后提供.retrieve(), .update() and .destroy() actions.

　　

Using generic class-based views

使用mixin类可以减少代码，但rest框架提供了一组已经mixin-in的通用视图，可以再次减少代码。

from rest_framework import generics

from .models import Course
from .serializer import CourseSerializer


class CourseList(generics.ListCreateAPIView):
    queryset = Course.objects.all()
    serializer_class = CourseSerializer


class CourseDetail(generics.RetrieveUpdateDestroyAPIView):
    queryset = Course.objects.all()
    serializer_class = CourseSerializer