基于类的视图
基于类的视图比先前基于函数的视图的可重用性更强，可以更多快好省地 ( DRY )地写出简洁的代码。
把 API 用基于类的视图的方式重写
编辑 douban/views.py 进行如下重写
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#!/usr/bin/python
# -*- coding: utf-8 -*-
from douban.models import Movies
from douban.serializer import MoviesSerializer
from django.http import Http404
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status
class MoviesList(APIView):
"""
罗列出所有的 Movies 或者 能新建一个 Movies
"""
def get(self, request, format=None):
movies = Movies.objects.all()
serializer = MoviesSerializer(movies, many=True)
return Response(serializer.data)
def post(self, request, format=None):
serializer = MoviesSerializer(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
class MoviesDetail(APIView):
"""
展示\更新或删除一个 Movies
"""
def get_object(self, pk):
try:
return Movies.objects.get(pk=pk)
except Movies.DoesNotExist:
raise Http404
def get(self, request, pk, format=None):
movies = self.get_object(pk)
serializer = MoviesSerializer(movies)
return Response(serializer.data)
def put(self, request, pk, format=None):
movies = self.get_object(pk)
serializer = MoviesSerializer(movies, 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):
movies = self.get_object(pk)
movies.delete()
return Response(status=status.HTTP_204_NO_CONTENT)
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并更新 douban/urls.py
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#!/usr/bin/python
# -*- coding: utf-8 -*-
from django.conf.urls import url
from rest_framework.urlpatterns import format_suffix_patterns
from douban import views
urlpatterns = [
url(r'^dbmovies/$', views.MoviesList.as_view()),
url(r'^dbmovies/(?P<pk>[0-9]+)/$', views.MoviesDetail.as_view()),
]
urlpatterns = format_suffix_patterns(urlpatterns)
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重写完毕！
使用 Mixins
使用基于类的视图的一大好处是，我们可以使用各种 mixins
DRF 为我们提供了许多现成的 mixins ，方便我们像使用 model-backed API 一样构建 “创建/获取/更新/删除” API. 我们试着使用 Mixins 改写原先的 views
GenericAPIView 为我们提供了 views 核心的功能, 而 ListModelMixin 和 CreateModelMixin 为我们提供了 .list() 和 .create() 功能，我们将这些功能与 http 动作的 GET 和 POST 相绑定:
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from douban.models import Movies
from douban.serializer import MoviesSerializer
from rest_framework import mixins
from rest_framework import generics
class MoviesList(mixins.ListModelMixin,
mixins.CreateModelMixin,
generics.GenericAPIView):
queryset = Movies.objects.all()
serializer_class = MoviesSerializer
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
return self.create(request, *args, **kwargs)
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同样的, 我们使用GenericAPIView, RetrieveModelMixin, UpdateModelMixin和DestroyModelMixin改写views.py:
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class MoviesDetail(mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
generics.GenericAPIView):
queryset = Movies.objects.all()
serializer_class = MoviesSerializer
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)
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可看出，这三个 Mixin 分别对应 GET/PUT/DELETE 动作。
使用通用类视图
使用 Mixin 来重写 views 减少了代码量，但是还可以更少！
那就是使用「通用类视图」—「generic class based views」
同 Django 一样，DRF为我们提供了现成的通用类视图，接下来我们使用这些通用类视图再一次修改原有的 views.py :
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from douban.models import Movies
from douban.serializer import MoviesSerializer
from rest_framework import generics
class MoviesList(generics.ListCreateAPIView):
queryset = Movies.objects.all()
serializer_class = MoviesSerializer
class MoviesDetail(generics.RetrieveUpdateDestroyAPIView):
queryset = Movies.objects.all()
serializer_class = MoviesSerializer
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这样，代码已经非常的精简了，不过坏处在于，你不知道他具体执行了什么。