drf框架 - 视图家族 | GenericAPIView | mixins | generics | viewsets

视图家族

view:视图
generics:工具视图
mixins:视图工具集
viewsets:视图集
学习曲线: APIView => GenericAPIView => mixins的五大工具类 => generics中的工具视图 => viewsets中的视图集

一.GenericAPIView基类

# GenericAPIView是继承APIView的,完全兼容APIView
# 重点:GenericAPIView在APIView基础上完成了哪些事?
1get_queryset():从类属性queryset中获得model的queryset数据
2get_object():从类属性queryset中获得model的queryset数据,再通过有名分组pk确定唯一操作对象
3)get_serializer():从类属性serializer_class中获得serializer的序列化类
  • 路由层

urlpatterns = [
    url(r'^v2/books/$', views.BookGenericAPIView.as_view()),
    url(r'^v2/books/(?P<pk>.*)/$', views.BookGenericAPIView.as_view()),
]
# BookGenericAPIView.as_view() => 调用的是APIView的as_view() => View的as_view() => APIView的dispatch完成分发
  • 视图层

from rest_framework.generics import GenericAPIView
# BookGenericAPIView.as_view() => 调用的是APIView的as_view() => View的as_view() => APIView的dispatch完成分发
class BookGenericAPIView(GenericAPIView):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer
    lookup_field = 'pk'  # 单查是要指定lookup_field = 'pk'属性
    # 群查:
    def get(self, request, *args, **kwargs):
        book_query = self.get_queryset()  # 会自动将queryset传入,得到model类的queryset对象
        book_ser = self.get_serializer(book_query, many=True)  # 等同于BookModelSerializer序列化
        book_data = book_ser.data
        return APIResponse(results=book_data)
    # 单查:
    def get(self, request, *args, **kwargs):
        book_obj = self.get_object()  # 会自动将queryset传入,并调用lookup_field属性,得到model类的具体的一条记录(即:对象)
        book_ser = self.get_serializer(book_obj)
        book_data = book_ser.data
        return APIResponse(results=book_data)

二.mixins视图工具集 - 辅助GenericAPIView

# 1)mixins有五个工具类文件,一共提供了五个工具类,六个工具方法:单查、群查、单增、单删、单整体改、单局部改
    - 群查 ListModelMixin | list() 
    - 单查 RetrieveModelMixin | retrieve()
    - 单增 CreateModelMixin | create()
    - UpdateModelMixin | update()单整体改 | partial_update()单局部改(单删:改字段)
    - DestroyModelMixin | destroy() 单删 注意:从数据库中删除,一般不用
# 2)继承工具类可以简化请求函数的实现体,但是必须继承GenericAPIView,需要GenericAPIView类提供的几个类属性和方法(见上方GenericAPIView基类知识点)
    属性: 
        - queryset | model类对象
        - serializer_class | 序列化类
        - lookup_field | 指定pk
    方法: 
        - get_queryset() | 拿到对象们
        - get_object() | 拿到具体的对象
        - get_serializer() | 序列化,反序列化
# 3)工具类的工具方法返回值都是Response类型对象,如果要格式化数据格式再返回给前台,可以通过 response.data 拿到工具方法返回的Response类型对象的响应数据
  • 路由层

urlpatterns = [
    url(r'^v3/books/$', views.BookMixinGenericAPIView.as_view()),
    url(r'^v3/books/(?P<pk>.*)/$', views.BookMixinGenericAPIView.as_view()),
]
  • 视图层

from rest_framework.mixins import ListModelMixin,RetrieveModelMixin,CreateModelMixin,UpdateModelMixin
class BookMixinGenericAPIView(ListModelMixin, RetrieveModelMixin, CreateModelMixin, UpdateModelMixin, GenericAPIView):
    # 继承GenericAPIView的目的:
    # 1.路由调用GenericAPIView父类APIView的as_view()方法
    # 2.调用APIView的dispatch完成方发
    # 3.需要GenericAPIView类提供的几个类属性和方法
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer
​
    def get(self, request, *args, **kwargs):
        if 'pk' in kwargs:
            # 单查:RetrieveModelMixin 中的retrieve()方法,内部是调用了GenericAPIView的get_object()方法
            response = self.retrieve(request, *args, **kwargs)
        else:
            # 群查:ListModelMixin 中的list()方法,内部是调用了GenericAPIView的get_serializer(queryset, many=True)方法
            response = self.list(request, *args, **kwargs)
        # mixins提供的方法响应的数据默认是Response
        # response.data即可拿到响应的数据
        print(response.data)  # {'字段':'字段值',...}
        return APIResponse(results=response.data)
​
    # 单增:CreateModelMixin 中的create()方法内部是调用了GenericAPIView的get_serializer(data=request.data)方法完成序列化,在保存
    def post(self, request, *args, **kwargs):
        response = self.create(request, *args, **kwargs)
        return APIResponse(results=response.data)
​
    # 单 整体改: UpdateModelMixin 中的update()方法内部是调用了GenericAPIView的get_object()拿到具体对象,使partial=False到达整体改
    def put(self, request, *args, **kwargs):
        response = self.update(request, *args, **kwargs)
        return APIResponse(results=response.data)
    # 单 局部改: UpdateModelMixin 中的update()方法内部是调用了GenericAPIView的get_object()拿到具体对象,使partial=True到达局部改
    def patch(self, request, *args, **kwargs):
        response = self.partial_update(request, *args, **kwargs)
        return APIResponse(results=response.data)

三.generics 工具视图 

1)工具视图都是GenericAPIView的子类,且不同的子类继承了不同的工具类,重写了请求方法
    -- UpdateAPIView: 2)工具视图的功能如果直接可以满足需求,只需要继承工具视图,提供queryset与serializer_class即可
  • 路由层

urlpatterns = [
    url(r'^v4/books/$', views.BookListCreatePIView.as_view()),
    url(r'^v4/books/(?P<pk>.*)/$', views.BookListCreatePIView.as_view()),
]
  • 视图层

from rest_framework.generics import ListCreateAPIView, UpdateAPIView
class BookListCreatePIView(ListCreateAPIView, UpdateAPIView):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer

四.viewsets 视图集

1)视图集都是优先继承ViewSetMixin类,再继承一个视图类(GenericAPIView或APIView)
#       GenericViewSet、ViewSet
2)ViewSetMixin提供了重写的as_view()方法,继承视图集的视图类,配置路由时调用as_view()必须传入 {请求名:函数名} 映射关系字典
#       eg: url(r'^v5/books/$', views.BookGenericViewSet.as_view({'get': 'my_get_list'})),
#       表示get请求会交给my_get_list视图函数处理
  • 路由层

urlpatterns = [
    # View的as_view():将get请求映射到视图类的get方法
    # ViewSet的as_view({'get': 'my_get_list'}):将get请求映射到视图类的my_get_list方法
    url(r'^v5/books/$', views.BookGenericViewSet.as_view({'get': 'my_get_list'})),
    url(r'^v5/books/(?P<pk>.*)/$', views.BookGenericViewSet.as_view({'get': 'my_get_obj'})),
]
  • 视图层

from rest_framework.viewsets import GenericViewSet
from rest_framework import mixins
class BookGenericViewSet(mixins.ListModelMixin, mixins.RetrieveModelMixin, GenericViewSet):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer
    # 群查
    def my_get_list(self, request, *args, **kwargs):
        return self.list(request, *args, **kwargs)
    # 单查
    def my_get_obj(self, request, *args, **kwargs):
        return self.retrieve(request, *args, **kwargs)

GenericAPIView 与 APIView 区别

# GenericAPIView 与 APIView 最为两大继承视图的区别
# 1)GenericViewSet和ViewSet都继承了ViewSetMixin,as_view都可以配置 {请求:函数} 映射关系
# 2)GenericViewSet继承的是GenericAPIView视图类,用来完成标准的 model 类操作接口
# 3)ViewSet继承的是APIView视图类,用来完成不需要 model 类参与,或是非标准的 model 类操作接口
#       post请求在标准的 model 类操作下就是新增接口,登陆的post不满足
#       post请求验证码的接口,不需要 model 类的参与
# 案例:登陆的post请求,并不是完成数据的新增,只是用post提交数据,得到的结果也不是登陆的用户信息,而是登陆的认证信息
'''
 继承关系: 
   APIView(View)

   GenericAPIView(APIView)

   GenericVieaSet(
                    ViewSetMixin,
                    generics.GenericAPIView)

   ModelViewSet(
       mixins.CreateModelMixin,增
       mixins.RetreveModelMixin,单查
        mixins.UpdateModelMixin,单/整改
       mixins.DestroyModelMixin,删
       mixins.ListModelMixin,群查
       GenericViewSet,路由{}映射
        )

        CreateAPIView(
                   mixins.CreateModelMixin,
                   GenericAPIView
                     )
        ListAPIView(
                  mixins.ListModelMixin,
                  GenericAPIView
                    )
        RetrieveAPIView(
                  mixins.RetrieveModelMixin,
                  GenericAPIView
                    )
        DestroyAPIView(
                   mixins.DestroyModelMixin,
                   GenericAPIView
                    )
        UpdateAPIView(
                    mixins.UpdateModelMixin,
                    GenericAPIView
                    )
        ListCreateAPIView(
                    mixins.ListModelMixin,
                    mixins.CreateModelMixin,
                    GenericAPIView
                    )
        RetrieveUpdateAPIView(
                    mixins.RetrieveModelMixin,
                    mixins.UpdateModelMixin,
                    GenericAPIView
                    )
        RetrieveDestroyAPIView(
                    mixins.RetrieveModelMixin,
                    mixins.DestroyModelMixin,
                    GenericAPIView
                    )
         RetrieveUpdateDestroyAPIView(
                    mixins.RetrieveModelMixin,
                    mixins.UpdateModelMixin,
                    mixins.DestroyModelMixin,
                    GenericAPIView
                    )
'''    
View Code

五.工具视图集 ModelViewSet

  • 视图层

# 拥有六大接口:单查、群查、单增、单删、单整体改、单局部改
# 注:一般肯定会重写destroy
from rest_framework.viewsets import ModelViewSet
class BookModelViewSet(ModelViewSet):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer
​
    # 单删 改字段
    def destroy(self, request, *args, **kwargs):
        instance = self.get_object()  # 拿到具体的model类
        if not instance:
            return APIResponse(1, '删除失败')
        # 改字段
        instance.is_delete = True
        instance.save()
        return APIResponse(0, '删除成功')
   
  • 路由层

urlpatterns = [
    url(r'^v6/books/$', views.BookModelViewSet.as_view({'get': 'list', 'post': 'create'})),
    url(r'^v6/books/(?P<pk>.*)/$', views.BookModelViewSet.as_view({'get': 'retrieve', 'put': 'update', 'patch': 'partial_update', 'delete': 'destroy'})),
] 

 总结:

"""
视图家族
1、视图类:APIView、GenericAPIView
    APIView:作为drf的基础view;as_view()禁用csrf;dispatch()二次封装request、三大认证、解析、渲染、响应、异常等模块;一堆类属性,可以用来做全局或局部插拔配置
    GenericAPIView:继承APIView;三个方法三个属性(obj,queryset,serializer)

2、视图工具集:mixin五大工具类(六个方法)
    mixin.ListModelMixin     - list:群查
    mixin.RetreveModelMixin  - retrieve:单查
    mixin.CreateModelMixin   - create:单增
    mixin.DestroyModelMixin  - destroy:单删
    mixin.UpdateModelMixin   - update:单整体改
    mixin.UpdateModelMixin   - partial_update:单局部改
    前提:工具类都是由GenericAPIView的子类来继承
  
3、视图工具:generic各种子类(共10个子类)
    ListAPIView(ListModelMixin, GenericAPIView):继承该类的视图类,只需要提供几个类属性,就可以完成群查,不需要书写get方法
    ListCreateAPIView(ListModelMixin, CreateModelMixin, GenericAPIView)


4、视图集:ViewSet、GenericViewSet
    ViewSetMixin:重写as_view(),可以将请求方法与视图类中的自定义函数名完成映射
        as_view({'get': 'list', 'post': 'my_post'})
        
    GenericViewSet:可以自定义请求映射的Model操作视图集
    
    ViewSet:可以自定义请求映射的任意操作视图集(一般与Model操作不是那么密切相关)
        登陆的post并非新增、短信的验证码(get或post)都和model无关 
"""

 

  名称                                       父类 请求方法 功能 特点
  APIView View post, get, put, patch, delete 增删改查 重写as_view()方法,二次封装request,三大认证,dispatch分发
generics.py GenericAPIView APIView post, get, put, patch, delete 增删改查 提供了三个方法三个属性(obj,queryset,serializer)
viewsets.py ViewSetMixin   post, get, put, patch, delete 增删改查 重写as_view()方法,请求方法与函数映射
ViewSet ViewSetMixin, APIView post, get, put, patch, delete 增删改查 提供映射 , dispatch分发
GenericViewSet ViewSetMixin, GenericAPIView post, get, put, patch, delete 增删改查 提供映射,  dispatch分发, 三个属性与方法
ModelViewSet mixins.CreateModelMixin,
mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
mixins.ListModelMixin,
GenericViewSet
post, get, put, patch, delete 增删改查  
mixins.py CreateModelMixin     提供create()方法, 内部用到get_serializer反序列化,所以需要其子类继承GenericAPIView
ListModelMixin     群查 提供list()方法, 内部用到get_serializer序列化,所以需要其子类继承GenericAPIView
RetrieveModelMixin     单查 提供retrieve()方法, 内部用到get_serializer,get_object,所以需要其子类继承GenericAPIView
UpdateModelMixin     单 局/整 改 提供update()方法, 内部用到get_serializer,get_object,所以需要其子类继承GenericAPIView
generics.py CreateAPIView mixins.CreateModelMixin, GenericAPIView post 提供create()方法,dispatch分发, 三个属性与方法
ListAPIView mixins.ListModelMixin, GenericAPIView get 群查 提供list()方法,dispatch分发, 三个属性与方法
RetrieveAPIView mixins.RetrieveModelMixin, GenericAPIView get 单查 提供retrieve()方法,dispatch分发, 三个属性与方法
UpdateAPIView mixins.UpdateModelMixin, GenericAPIView put/patch 单 局/整 改 提供update(), partial_update()方法,dispatch分发, 三个属性与方法
ListCreateAPIView mixins.ListModelMixin, mixins.CreateModelMixin, GenericAPIView get/post 群查/单增 提供list(),create()方法,dispatch分发, 三个属性与方法

 

路由组件 routers 

from django.conf.urls import include
from rest_framework.routers import SimpleRouter
router = SimpleRouter()  # SimpleRouter类内部做了{请求:函数}的映射关系
# 所有路由与ViewSet视图类的都可以注册,会产生 '^v6/books/$' 和 '^v6/books/(?P<pk>[^/.]+)/$'
router.register('v6/books', views.BookModelViewSet)
​
urlpatterns = [
    # 第一种添加子列表方式
    url(r'^', include(router.urls)),
]
# 第二种添加子列表方式
# urlpatterns.extend(router.urls)

 SimpleRouter 源码:

class SimpleRouter(BaseRouter):
    # 没有 pk 时做的映射关系
     routes = [
        # List route.
        Route(
            url=r'^{prefix}{trailing_slash}$',  # 没有pk
            # 映射关系
            mapping={
                'get': 'list',
                'post': 'create'
            },
            name='{basename}-list',
            detail=False,
            initkwargs={'suffix': 'List'}
        ),
    # 有 pk 时做的映射关系
     Route(
            url=r'^{prefix}/{lookup}{trailing_slash}$',  # 有pk
            # 映射关系
            mapping={
                'get': 'retrieve',
                'put': 'update',
                'patch': 'partial_update',
                'delete': 'destroy'
            },
            name='{basename}-detail',
            detail=True,
            initkwargs={'suffix': 'Instance'}
        ),

 

posted @ 2019-10-20 14:03  waller  阅读(731)  评论(2编辑  收藏  举报