Django REST framework视图的用法

前言

在了解了REST farmwork封装的视图类之后，我对python的面向对象有了更深刻的理解。

Django RESR framework框架内置的视图类充分发挥了面向对象封装与继承的特性。

自己写一个类似于DRF内置视图类的功能

实现一个图书出版社的增、删、改、查、查功能，两个查一个是查所有出版社，一个是查具体的某一个出版社。

首先是一个简略的表结构设计models.py：

from django.db import modelsclass Publisher(models.Model):  name = models.CharField(max_length=16)  def __str__(self):    return self.nameclass Author(models.Model):  name = models.CharField(max_length=16)  def __str__(self):    return self.nameclass Book(models.Model):  title = models.CharField(max_length=32)  CHOICES = ((1, 'Python'), (2, 'Go'), (3, 'Linux'))  category = models.IntegerField(choices=CHOICES)  pub_date = models.DateField()  publisher = models.ForeignKey(to='Publisher', on_delete=models.CASCADE)  authors = models.ManyToManyField(to='Author')  def __str__(self):    return self.title

然后是路由url：

将用到pk,与不用到pk的路由业务区分开

from django.contrib import adminfrom django.urls import path, re_pathfrom bms import viewsurlpatterns = [  path('admin/', admin.site.urls),  # 查所有对象，与添加对象  re_path(r'publishers/$', views.PublisherView.as_view()),  # 带pk查询具体某一条数据  re_path(r'publishers/(?P<pk>/d+)/$', views.PublisherDetailView.as_view()), # 出版社详情]

再到序列化类，自创建的serializers.py

这里我省略了新增需要重写的create方法和更新需要重写的update方法。

from bms import modelsfrom rest_framework import serializersclass PublisherModelSerializer(serializers.ModelSerializer):  class Meta:    model = models.Publisher    fields = "__all__"class AuthorModelSerializer(serializers.ModelSerializer):  class Meta:    model = models.Author    fields = "__all__"

最后视图views.py

from bms import modelsfrom rest_framework.views import APIViewfrom rest_framework.response import Responsefrom bms.serializers import PublisherModelSerializer##################### 面向对象，手动实现REST framework视图功能##################class GenericView(APIView):  '''公用类'''  queryset = None  serializer_class = None  def get_queryset(self):    # 让每一次请求来的时候都现查一次数据    print('GeneriView------',self)    return self.queryset.all()  def get_object(self, request, pk):    # 获取具体queryset    return self.get_queryset().filter(pk=pk)class ListMixin(object):  # mixi.n 混合类，不能单独使用，利用python支持多继承  def get(self, request):    print('ListMixin------------', self)    queryset = self.get_queryset()    ser_obj = self.serializer_class(queryset, many=True)    return Response(ser_obj.data)class CreateMixin(object):  def post(self, request):    ser_obj = self.serializer_class(data=request.data)    if ser_obj.is_valid():      ser_obj.save()      return Response("ok")    else:      return Response(ser_obj.errors)class RetrieveMixin(object):  """ 获取具体某一条记录"""  def retrieve(self, request, pk):    '''将此get方法与ListMixin中的get方法区分'''    obj = self.get_object(request, pk).first()    if obj:      ser_obj = self.serializer_class(obj)      return Response(ser_obj.data)    else:      return Response("无效的id")class UpdateMixin(object):  def put(self, request, pk):    obj = self.get_object(request, pk).first()    if obj:      ser_obj = self.serializer_class(instance=obj, data=request.data, partial=True)      if ser_obj.is_valid():        ser_obj.save()        return Response(ser_obj.data)      else:        return Response(ser_obj.errors)    else:      return Response("无效的id")class DestroyMixin(object):  def delete(self, request, pk):    obj = self.get_object(request, pk)    if obj:      obj.delete()      return Response("删除成功")    else:      return Response("无效的id")class RetrieveView(GenericView, RetrieveMixin):  '''因两个get方法相冲图，在此曲线访问查询具体对象的get方法'''  def get(self, request, pk):    return self.retrieve(request, pk)# 出版社class PublisherView(GenericView, ListMixin, CreateMixin):  '''查所有出版社，增加出版社'''  # 只用写配置项  queryset = models.Publisher.objects.all()  serializer_class = PublisherModelSerializerclass PublisherDetailView(RetrieveView, UpdateMixin, DestroyMixin):  '''查询具体某一出版社，编辑，删除'''  queryset = models.Publisher.objects.all()  serializer_class = PublisherModelSerializer