21、Django_rest framework_Concret

在上一章优化了的基础上，再次优化

from projects.models import Projects
from projects.serializer import ProjectModelSerializer
from rest_framework.generics import GenericAPIView
from django_filters.rest_framework import DjangoFilterBackend
from rest_framework import mixins

## 注意先继承mixins的方法
class ProjectsList(mixins.ListModelMixin,
                   mixins.CreateModelMixin,
                   GenericAPIView):
    ordering_fields = ['name', 'leader']
    queryset =Projects.objects.all()
    serializer_class = ProjectModelSerializer
    filter_backends = [DjangoFilterBackend]
    filterset_fields = ['name', 'desc']

    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 ProjectDetail(mixins.RetrieveModelMixin,
                    mixins.UpdateModelMixin,
                    mixins.DestroyModelMixin,
                    GenericAPIView):

    queryset = Projects.objects.all()
    serializer_class = ProjectModelSerializer    
    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)

一、generics/Concrete Generic Views

从该文件的类方法源码，可以看到这些方法都继承了mixins和GenericAPIView类，并实现了和上面的get/post等方法的组合的方法
比如rest_framework.generics.ListCreateAPIView：

class ListCreateAPIView(mixins.ListModelMixin,
                        mixins.CreateModelMixin,
                        GenericAPIView):
    
"""    
Concrete view for listing a queryset or creating a model instance.  
"""
    def get(self, request, *args, **kwargs):        
        return self.list(request, *args, **kwargs)
    def post(self, request, *args, **kwargs):        
        return self.create(request, *args, **kwargs)

generics/Concrete Generic Views中的类，可以根据自己的需要来继承这些类

• RetrieveAPIView
  1.提供get方法
  2.继承：RetrieveModelMixin、GenericAPIView
• UpdateAPIView
  1.提供put、patch方法
  2.继承：UpdateModelMixin、GenericAPIView
• DestroyAPIView
  1.提供delete方法
  2.继承：DestoryModelMixin、GenericAPIView
• ListAPIView
  1.提供get方法
  2.继承：ListModelMixin、GenericAPIView
• CreateAPIView
  1.提供post方法
  2.继承：CreateModelMixin、GenericAPIView
• ListCreateAPIView
  1.提供post、get方法
  2.继承：ListModelMixin、CreateModelMixin、GenericAPIView
• RetrieveUpdateAPIView
  1.提供get、delete方法
  2.继承：RetrieveModelMixin、DestoryModelMixin、GenericAPIView
• RetrieveUpdateDestoryAPIView
  1.提供get、put、delete方法
  2.继承：RetrieveModelMixin、UpdateModelMixin、DestoryModelMixin、GenericAPIView

所以，可以直接继承generics中满足所需的方法，并可优化成：

from projects.models import Projects
from projects.serializer import ProjectModelSerializer
from django_filters.rest_framework import DjangoFilterBackend
from rest_framework import generics
class ProjectsList(generics.ListCreateAPIView):
    ordering_fields = ['name', 'leader']
    queryset = Projects.objects.all()
    serializer_class = ProjectModelSerializer
    filter_backends = [DjangoFilterBackend]
    filterset_fields = ['name', 'leader', 'tester']
class ProjectDetail(generics.RetrieveUpdateDestroyAPIView):
    queryset = Projects.objects.all()
    serializer_class = ProjectModelSerializer

generics/Concrete Generic Views的痛点

• 上面的代码中，还是有两个类视图，还不能合并
• 两个类视图中，有相同的get方法，会冲突
• 两个类视图所对应的url地址依旧不一致