DRF 视图组件

DRF框架提供了很多通用的视图基类与扩展类，上篇使用的APIView是比较偏Base的，视图的使用更加简化了代码，这里介绍一下其他视图的用法

Django REST framwork 提供的视图的主要作用：

控制序列化器的执行（检验、保存、转换数据）
控制数据库查询的执行

先来看看这其中的人情世故：两个视图基本类，五个扩展类，九个视图子类，视图集方法，视图集··

视图组件大纲

两个视图基本类

导入：

from rest_framework.views import APIView
from rest_framework.generics import GenericAPIView

APIView：DRF最顶层视图类
GenericAPIView：DRF通用视图类

五个扩展类

扩展类不是视图类，没有集成APIView，需要配合GenericAPIView使用，因为五个扩展类的实现需要调用GenericAPIView提供的序列化器与数据库查询的方法

主要是用来对数据进行增删改查

导入

from rest_framework.mixins import CreateModelMixin,ListModelMixin,DestroyModelMixin,RetrieveModelMixin,UpdateModelMixin

CreateModelMixin
ListModelMixin
DestroyModelMixin
RetrieveModelMixin
UpdateModelMixin

九个子类视图

导入

from rest_framework.generics import  CreateAPIView,ListAPIView,DestroyAPIView,RetrieveAPIView,UpdateAPIView,ListCreateAPIView,RetrieveUpdateAPIView,RetrieveUpdateDestroyAPIView,RetrieveDestroyAPIView

视图子类其实可以理解为GenericAPIView通用视图类和Mixin扩展类的排列组合组成的，底层事通过封装和继承来写

CreateAPIView

提供 post 方法
继承自： GenericAPIView、CreateModelMixin

ListAPIView

提供 get 方法
继承自：GenericAPIView、ListModelMixin

DestroyAPIView

提供 delete 方法
继承自：GenericAPIView、DestoryModelMixin

RetrieveAPIView

提供 get 方法
继承自: GenericAPIView、RetrieveModelMixin

UpdateAPIView

提供 put 和 patch 方法
继承自：GenericAPIView、UpdateModelMixin

ListCreateAPIView

提供get 和 post方法
继承自：ListModelMixin、CreateModelMixin、GenericAPIView

RetrieveUpdateAPIView

提供 get、put、patch方法
继承自： GenericAPIView、RetrieveModelMixin、UpdateModelMixin

RetrieveDestroyAPIView

提供：get、delete方法
继承自：RetrieveModelMixin、DestroyModelMixin、GenericAPIView

RetrieveUpdateDestroyAPIView

提供 get、put、patch、delete方法
继承自：GenericAPIView、RetrieveModelMixin、UpdateModelMixin、DestoryModelMixin

导入

from rest_framework.viewsets import ModelViewSet,ReadOnlyModelViewSet,ViewSet,GenericViewSet,ViewSetMixin

常用视图集父类#

ModelViewSet：继承自GenericViewSet，同时包括了ListModelMixin、RetrieveModelMixin、CreateModelMixin、UpdateModelMixin、DestoryModelMixin。
ReadOnlyModelViewSet：继承自GenericViewSet，同时包括了ListModelMixin、RetrieveModelMixin。
ViewSet：继承自APIView与ViewSetMixin，作用也与APIView基本类似，提供了身份认证、权限校验、流量管理等。ViewSet主要通过继承ViewSetMixin来实现在调用as_view()时传入字典（{'get':'list'}）的映射处理工作。
- 在ViewSet中，没有提供任何动作action方法，需要我们自己实现action方法。
GenericViewSet：使用ViewSet通常并不方便，因为list、retrieve、create、update、destory等方法都需要自己编写，而这些方法与前面讲过的Mixin扩展类提供的方法同名，所以我们可以通过继承Mixin扩展类来复用这些方法而无需自己编写。但是Mixin扩展类依赖与GenericAPIView，所以还需要继承GenericAPIView。
- GenericViewSet就帮助我们完成了这样的继承工作，继承自GenericAPIView与ViewSetMixin,在实现了调用as_view()时传入字典（如{'get':'list'}`）的映射处理工作的同时，还提供了GenericAPIView提供的基础方法，可以直接搭配Mixin扩展类使用。

魔法类#

ViewSetMixin：控制自动生成路由

DRF中视图的“七十二变”

第一层是继承APIView写，第二层基于基于GenericAPIView写，第三层基于GenericAPIView+五个扩展类写，第四层通过九个视图子类来写，第五层是通过ViewSet写

ps：第几层是我意淫出来的词不要介意~，一层更比一层牛，欲练此功必先自宫！！！

第一层：基于APIview的五个接口

class BookView(APIView):
    def get(self, requets):
        # 序列化
        book_list = models.Book.objects.all()
        # 序列化多条数据many=True
        ser = serializer.BookSerializer(instance=book_list, many=True)
        return Response(ser.data)

    def post(self, request):
        # 获取反序列化数据
        ser = serializer.BookSerializer(data=request.data)
        if ser.is_valid():
            # 校验通过存入数据库，不需要重写create方法了
            ser.save()
            return Response({'code': 100, 'msg': '新增成功', 'data': ser.data})
        # 校验失败
        return Response({'code': 101, 'msg': '校验未通过', 'error': ser.errors})


class BookViewDetail(APIView):
    def get(self, request, pk):
        book = models.Book.objects.filter(pk=pk).first()
        ser = serializer.BookSerializer(instance=book)
        return Response(ser.data)

    def put(self, request, pk):
        book = models.Book.objects.filter(pk=pk).first()
        # 修改，instance和data都要传
        ser = serializer.BookSerializer(instance=book, data=request.data)
        if ser.is_valid():
            # 校验通过修改，不需要重写update
            ser.save()
            return Response({'code:': 100, 'msg': '修改成功', 'data': ser.data})
        # 校验不通过
        return Response({'code:': 102, 'msg': '校验未通过，修改失败', 'error': ser.errors})

    def delete(self, request, pk):
        models.Book.objects.filter(pk=pk).delete()
        return Response({'code': 100, 'msg': '删除成功'})

第一层五个接口demo#

ModelSerializer序列化器实战 - HammerZe - 博客园 (cnblogs.com)

第二层：基于GenericAPIView的五个接口

常用类属性：#

-GenericAPIView   继承了APIView，封装了一些属性和方法，跟数据库打交道
  	-queryset = None # 指定序列化集
    -serializer_class = None  # 指定序列化类
    -lookup_field = 'pk'  # 查询单条，分组分出来的参数，转换器对象参数的名字
    -filter_backends   # 过滤排序功能会用它
    -pagination_class  # 分页功能
    
    -get_queryset()  # 获取要序列化的数据,后期可能会重写
    -get_object()    # 通过lookup_field查询的
    -get_serializer()  # 使用它序列化
    -get_serializer_class() # 返回序列化类 ，后期可能重写
    
    
    
demo：
# 指定序列化集
queryset = models.Book.objects.all()
# 指定序列化类
serializer_class = serializer.BookSerializer

第二层五个接口demo#

from rest_framework.response import Response


from app01 import models
from app01 import serializer
from rest_framework.generics import GenericAPIView
# 书视图类
class BookView(GenericAPIView):
    # 指定序列化集
    queryset = models.Book.objects.all()
    # 指定序列化类
    serializer_class = serializer.BookSerializer
    def get(self, requets):
        # obj = self.queryset()
        obj = self.get_queryset() # 等同于上面
        # ser = self.get_serializer_class()(instance=obj,many=True)
        ser = self.get_serializer(instance=obj,many=True) # 等同于上面
        return Response(ser.data)

    def post(self, request):
        # 获取反序列化数据
        # ser = serializer.BookSerializer(data=request.data)
        ser = self.get_serializer(data = request.data)
        if ser.is_valid():
            # 校验通过存入数据库，不需要重写create方法了
            ser.save()
            return Response({'code': 100, 'msg': '新增成功', 'data': ser.data})
        # 校验失败
        return Response({'code': 101, 'msg': '校验未通过', 'error': ser.errors})


class BookViewDetail(GenericAPIView):
    # 指定序列化集
    queryset = models.Book.objects.all()
    # 指定序列化类
    serializer_class = serializer.BookSerializer
    def get(self, request, pk):
        # book = models.Book.objects.filter(pk=pk).first()
        book = self.get_object() # 根据pk拿到单个对象
        # ser = serializer.BookSerializer(instance=book)
        ser = self.get_serializer(instance=book)
        return Response(ser.data)

    def put(self, request, pk):
        # book = models.Book.objects.filter(pk=pk).first()
        book = self.get_object()
        # 修改，instance和data都要传
        # ser = serializer.BookSerializer(instance=book, data=request.data)
        ser = self.get_serializer(instance=book,data=request.data)
        if ser.is_valid():
            # 校验通过修改，不需要重写update
            ser.save()
            return Response({'code:': 100, 'msg': '修改成功', 'data': ser.data})
        # 校验不通过
        return Response({'code:': 102, 'msg': '校验未通过，修改失败', 'error': ser.errors})

    def delete(self, request, pk):
        # models.Book.objects.filter(pk=pk).delete()
        self.get_object().delete()
        return Response({'code': 100, 'msg': '删除成功'})

路由

path('books/', views.BookView.as_view()),
path('books/<int:pk>', views.BookViewDetail.as_view())

总结：到第二层只需修改queryset和serializer_class类属性即可，其余都不需要修改

注意：虽然pk没有在orm语句中过滤使用，但是路由分组要用，所以不能删，或者写成*args **kwargs接收多余的参数，且路由转换器必须写成pk

# 源码
lookup_field = 'pk'
lookup_url_kwarg = None

get_queryset()方法可以重写，如果我们需要在一个视图类内操作另外表模型，来指定序列化的数据

class BookViewDetail(GenericAPIView):
    queryset = models.Book.objects.all()
    ···
    '''
    指定序列化数据的格式：
    self.queryset()
    self.get_queryset() # 等同于上面
    queryset = models.Book.objects.all()
    '''
	# 可以重写get_queryset方法在book视图类里操作作者模型
    def get_queryset(self,request):
        if self.request.path == '/user'
        return Author.objects.all()
    ···
    # 这样序列化的数据就不一样了，根据不同的条件序列化不同的数据
    
    '''当然还可以通过重写get_serializer_class来返回其他序列化器类'''

第三层：基于GenericAPIView+五个视图扩展类写

五个视图扩展类：from rest_framework.mixins import CreateModelMixin,ListModelMixin,DestroyModelMixin,RetrieveModelMixin,UpdateModelMixin

通过GenericAPIView+视图扩展类来使得代码更简单，一个接口对应一个扩展类，注意扩展类不是视图类

ListModelMixin：获取所有API，对应list()方法
CreateModelMixin：新增一条API，对应create()方法
UpdateModelMixin：修改一条API，对应update()方法
RetrieveModelMixin：获取一条API，对应retrieve()方法
DestroyModelMixin：删除一条API，对应destroy()方法

注意：CreateModelMixin扩展类提供了更高级的方法，可以通过重写来校验数据存入

    def perform_create(self, serializer):
        serializer.save()

第三层五个接口demo#

from app01 import models
from app01 import serializer
from rest_framework.generics import GenericAPIView
from rest_framework.mixins import CreateModelMixin,ListModelMixin,DestroyModelMixin,RetrieveModelMixin,UpdateModelMixin

# 获取所有和新增API
class BookView(ListModelMixin,CreateModelMixin,GenericAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer
    def get(self, request):
       return super().list(request)

    def post(self, request):
        return super().create(request)

# 获取删除修改单个API
class BookViewDetail(UpdateModelMixin,RetrieveModelMixin,DestroyModelMixin,GenericAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer
    def get(self, request, *args,**kwargs):
        return super().retrieve(request, *args,**kwargs)

    def put(self, request, *args,**kwargs):
        return super().update(request, *args,**kwargs)

    def delete(self, request, *args,**kwargs):
        return super().destroy(request, *args,**kwargs)

总结

通过进一次封装+继承代码也变得越来越少了

GenericAPIView速写五个接口demo#

模型

from django.db import models


# Create your models here.

# build four model tables

class Book(models.Model):
    name = models.CharField(max_length=32)
    price = models.DecimalField(decimal_places=2, max_digits=5)
    publish = models.ForeignKey(to='Publish', on_delete=models.CASCADE)
    authors = models.ManyToManyField(to='Author')
    def __str__(self):
        return self.name

    # 自定制字段
    @property
    def publish_detail(self):
        return {'name': self.publish.name, 'addr': self.publish.city}


    @property
    def author_list(self):
        l = []
        print(self.authors.all()) # <QuerySet [<Author: Author object (1)>, <Author: Author object (2)>]>

        for author in self.authors.all():
            print(author.author_detail) # AuthorDetail object (1)
            l.append({'name': author.name, 'age': author.age, 'addr': author.author_detail.addr})
        return l


class Author(models.Model):
    name = models.CharField(max_length=32)
    age = models.IntegerField()
    author_detail = models.OneToOneField(to='AuthorDetail', on_delete=models.CASCADE)

    def __str__(self):
        return self.name

    @property
    def authordetail_info(self):
        return {'phone':self.author_detail.telephone,'addr':self.author_detail.addr}


class AuthorDetail(models.Model):
    telephone = models.BigIntegerField()
    addr = models.CharField(max_length=64)


class Publish(models.Model):
    name = models.CharField(max_length=32)
    city = models.CharField(max_length=32)
    email = models.EmailField()

序列化器

from django.db import models


# Create your models here.

# build four model tables

class Book(models.Model):
    name = models.CharField(max_length=32)
    price = models.DecimalField(decimal_places=2, max_digits=5)
    publish = models.ForeignKey(to='Publish', on_delete=models.CASCADE)
    authors = models.ManyToManyField(to='Author')
    def __str__(self):
        return self.name

    # 自定制字段
    @property
    def publish_detail(self):
        return {'name': self.publish.name, 'addr': self.publish.city}


    @property
    def author_list(self):
        l = []
        print(self.authors.all()) # <QuerySet [<Author: Author object (1)>, <Author: Author object (2)>]>

        for author in self.authors.all():
            print(author.author_detail) # AuthorDetail object (1)
            l.append({'name': author.name, 'age': author.age, 'addr': author.author_detail.addr})
        return l


class Author(models.Model):
    name = models.CharField(max_length=32)
    age = models.IntegerField()
    author_detail = models.OneToOneField(to='AuthorDetail', on_delete=models.CASCADE)

    def __str__(self):
        return self.name

    @property
    def authordetail_info(self):
        return {'phone':self.author_detail.telephone,'addr':self.author_detail.addr}


class AuthorDetail(models.Model):
    telephone = models.BigIntegerField()
    addr = models.CharField(max_length=64)


class Publish(models.Model):
    name = models.CharField(max_length=32)
    city = models.CharField(max_length=32)
    email = models.EmailField()

视图

from rest_framework.generics import GenericAPIView
from rest_framework.mixins import ListModelMixin, CreateModelMixin, DestroyModelMixin, RetrieveModelMixin, \
    UpdateModelMixin

from app01 import models
from app01 import serializer


# 书视图类
class BookView(ListModelMixin, CreateModelMixin, GenericAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

    def get(self, request):
        return super().list(request)

    def post(self, request):
        return super().create(request)


class BookViewDetail(RetrieveModelMixin, DestroyModelMixin, UpdateModelMixin, GenericAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

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

    def put(self, request, *args, **kwargs):
        return super().update(request, *args, **kwargs)

    def delete(self, request, *args, **kwargs):
        return super().destroy(request, *args, **kwargs)


# 作者
class AuthorView(ListModelMixin, CreateModelMixin, GenericAPIView):
    queryset = models.Author.objects.all()
    serializer_class = serializer.AuthorSerializer

    def get(self, request):
        return super().list(request)

    def post(self, request):
        return super().create(request)


class AuthorViewDetail(RetrieveModelMixin, DestroyModelMixin, UpdateModelMixin, GenericAPIView):
    queryset = models.Author.objects.all()
    serializer_class = serializer.AuthorSerializer

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

    def put(self, request, *args, **kwargs):
        return super().update(request, *args, **kwargs)

    def delete(self, request, *args, **kwargs):
        return super().destroy(request, *args, **kwargs)


# 作者详情

class AuthorDetailView(ListModelMixin, CreateModelMixin, GenericAPIView):
    queryset = models.AuthorDetail.objects.all()
    serializer_class = serializer.AuthorDetailSerializer

    def get(self, request):
        return super().list(request)

    def post(self, request):
        return super().create(request)


class OneAuthorViewDetail(RetrieveModelMixin, DestroyModelMixin, UpdateModelMixin, GenericAPIView):
    queryset = models.AuthorDetail.objects.all()
    serializer_class = serializer.AuthorDetailSerializer

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

    def put(self, request, *args, **kwargs):
        return super().update(request, *args, **kwargs)

    def delete(self, request, *args, **kwargs):
        return super().destroy(request, *args, **kwargs)


# 出版社
class PublishView(ListModelMixin, CreateModelMixin, GenericAPIView):
    queryset = models.Publish.objects.all()
    serializer_class = serializer.PublishSerializer

    def get(self, request):
        return super().list(request)

    def post(self, request):
        return super().create(request)


class PublishViewDetail(RetrieveModelMixin, DestroyModelMixin, UpdateModelMixin, GenericAPIView):
    queryset = models.Publish.objects.all()
    serializer_class = serializer.PublishSerializer

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

    def put(self, request, *args, **kwargs):
        return super().update(request, *args, **kwargs)

    def delete(self, request, *args, **kwargs):
        return super().destroy(request, *args, **kwargs)

路由

from django.contrib import admin
from django.urls import path

from app01 import views

urlpatterns = [
    path('admin/', admin.site.urls),
    # 书
    path('books/', views.BookView.as_view()),
    path('books/<int:pk>', views.BookViewDetail.as_view()),

    # 作者
    path('authors/', views.AuthorView.as_view()),
    path('authors/<int:pk>', views.AuthorViewDetail.as_view()),

    # 作者详情
    path('authorsdetail/', views.AuthorDetailView.as_view()),
    path('authorsdetail/<int:pk>', views.OneAuthorViewDetail.as_view()),

    # 出版社
    path('publish/', views.PublishView.as_view()),
    path('publish/<int:pk>', views.PublishViewDetail.as_view()),
]

Postman以及测完，请放心使用~

第四层：GenericAPIView+九个视图子类写五个接口

导入视图子类：from rest_framework.generics import CreateAPIView,ListAPIView,DestroyAPIView,RetrieveAPIView,UpdateAPIView,ListCreateAPIView,RetrieveUpdateAPIView,RetrieveUpdateDestroyAPIView,RetrieveDestroyAPIView

使用哪个继承哪个就可以了，具体可以看继承的父类里有什么方法不需要刻意去记

from rest_framework.generics import  CreateAPIView,ListAPIView,DestroyAPIView,RetrieveAPIView,UpdateAPIView,ListCreateAPIView,RetrieveUpdateAPIView,RetrieveUpdateDestroyAPIView,RetrieveDestroyAPIView

# 1、查询所有,新增API
class BookView(ListCreateAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer
# 2、新增接口
class BookView(CreateAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer
# 3、查询接口
class BookView(ListAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

# 4、查询单个，修改一个，删除一个接口
class BookViewDetail(RetrieveUpdateDestroyAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

# 5、查询单个接口
class BookViewDetail(RetrieveAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

# 6、修改单个接口
class BookViewDetail(UpdateAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

# 7、删除单个接口
class BookViewDetail(DestroyAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

# 8、查询单个、修改接口
class BookViewDetail(RetrieveUpdateAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer


# 9、查询单个、删除接口
class BookViewDetail(RetrieveDestroyAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

'''上述共九个视图子类，九九归一剑诀~'''

# 更新和删除接口自己整合
class BookViewDetail(UpdateAPIView,DestroyAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

第四层快速写五个接口demo#

from rest_framework.generics import ListCreateAPIView, RetrieveUpdateDestroyAPIView

from app01 import models
from app01 import serializer

class BookView(ListCreateAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

class BookViewDetail(RetrieveUpdateDestroyAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer
'''其余的和第三层一样'''

第五层：基于ViewSet写五个接口

视图集导入：from rest_framework.viewsets import ModelViewSet,ReadOnlyModelViewSet,ViewSet,GenericViewSet,ViewSetMixin

路由导入：from rest_framework.routers import SimpleRouter,DefaultRouter

基于ViewSet视图集写，需要我们配置路由

from django.urls import path, include
from rest_framework.routers import SimpleRouter
from app01 import views

router = SimpleRouter()
router.register('books', views.BookView, 'books')
urlpatterns = [
    ...
]
urlpatterns += router.urls
'''
register(self, prefix, viewset, basename=None)
prefix：路由url前缀
viewset：处理请求的viewset类
basename：路由名称的前缀，一般和prefix写成一样就行
'''
# 等同于
path('books/'),include(router.urls)
path('books/<int:pk>'),include(router.urls)

router = SimpleRouter()
router.register('books', views.BookView, 'books')

urlpatterns = [
    ...
    url(r'^', include(router.urls))
]


# 生成两种路由
path('/api/v1'),include(router.urls)
# [<URLPattern '^books/$' [name='books-list']>, <URLPattern '^books/(?P<pk>[^/.]+)/$' [name='books-detail']>]
# 等同于自己配的
path('/api/v1/books/'),include(router.urls)
path('/api/v1/books/<int:pk>'),include(router.urls)

异同：

同：方法一和方法二都可以自动生成路由，代替了下面的路由

path('books/', views.BookView.as_view()),
path('books/<int:pk>', views.BookViewDetail.as_view()),

异：方法二可以拼接路径，如果不拼接是和方法一一样的

两种不同的路由

第五层基于ModelViewSet视图集写五个接口demo#

views.py

from rest_framework.viewsets import ModelViewSet,ReadOnlyModelViewSet,ViewSet,GenericViewSet,ViewSetMixin
class BookView(ModelViewSet):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

urls.py

from django.contrib import admin
from django.urls import path, include
from rest_framework.routers import SimpleRouter

from app01 import views

router = SimpleRouter()
router.register('books', views.BookView, 'books')

urlpatterns = [
    path('admin/', admin.site.urls),
    path('api/v1/',include(router.urls)),
]

ps：剩下的都一样~

ReadOnlyModelViewSet视图集#

继承该ReadOnlyModelViewSet视图集的作用是只读，只做查询，修改删除等操作不允许

from rest_framework.viewsets import ModelViewSet,ReadOnlyModelViewSet,ViewSet,GenericViewSet,ViewSetMixin
class BookView(ReadOnlyModelViewSet):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer

两个视图集总结：#

ModelViewSet可以写五个接口，而ReadOnlyModelViewSet只能写两个接口

本质

ModelViewSet继承了五个视图扩展类+GenericViewSet，GenericViewSet继承了ViewSetMixin+GenericAPIView

PS：ViewSetMixin控制了路由写法
ReadOnlyModelViewSet继承了RetrieveModelMixin+ListModelMixin+GenericViewSet

其他视图集#

ViewSet#

ViewSet = ViewSetMixin+APIView


class ViewSet(ViewSetMixin, views.APIView):
    """
    The base ViewSet class does not provide any actions by default.
    """
    pass

GenericViewSet#

GenericViewSet = ViewSetMixin+GenericAPIView

class GenericViewSet(ViewSetMixin, generics.GenericAPIView):
    """
    The GenericViewSet class does not provide any actions by default,
    but does include the base set of generic view behavior, such as
    the `get_object` and `get_queryset` methods.
    """
    pass

ViewSetMixin#

魔术视图类，控制自动生成路由，可以通过组合继承，以前的写法可以继续使用，但是如果要自动生成路由必须得继承ViewSetMixin及其子类；或者选择继承ViewSet、GenericViewSet

class ViewSetMixin:
    """
    This is the magic.

    Overrides `.as_view()` so that it takes an `actions` keyword that performs
    the binding of HTTP methods to actions on the Resource.

    For example, to create a concrete view binding the 'GET' and 'POST' methods
    to the 'list' and 'create' actions...

    view = MyViewSet.as_view({'get': 'list', 'post': 'create'})
    """
这就是魔法。  
 
重写' .as_view() '，以便它接受一个' actions '关键字执行  
将HTTP方法绑定到资源上的动作。  
 
例如，创建绑定'GET'和'POST'方法的具体视图  
到“列表”和“创建”动作…  
 
= MyViewSet视图。 As_view ({'get': 'list'， 'post': 'create'})

第一层：基于APIView写视图，get、post、put、delete都需要自己写，序列化的数据和序列化类需要获取后指定

class BookView(APIView):
    def get(self, requets):
        book_list = models.Book.objects.all()
        ser = serializer.BookSerializer(instance=book_list, many=True)
        return Response(ser.data)

第二层：基于GenericAPIView写视图，优化了视图类内序列化数据和序列化类的代码冗余问题，通过queryset和serializer_class指定序列化集和序列化器即可，一个视图类内写一次即可，最后通过get_queryset和get_serializer方法处理
```
class BookView(GenericAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer
    def get(self, requets):
        obj = self.get_queryset() 
        ser = self.get_serializer(instance=obj,many=True) 
        return Response(ser.data)
```

第三层：基于GenericAPIView+5个视图扩展类写视图，每个扩展类对应一个接口，更加细化，通过继承父类(扩展类)减少了代码的冗余

class BookView(ListModelMixin,CreateModelMixin,GenericAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer
    def get(self, request):
       return super().list(request)

第四层，基于九个视图子类写，视图子类将扩展类和GenericAPIView封装到一块，使得我们要写的代码更少了，总之就是牛逼~
```
class BookView(ListCreateAPIView):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer
```

第五层，基于ViewSet写视图，这样以来5个接口就都在一个视图类内，代码更少了，但是可扩展性低了，路由也是问题，get所有和get一条路由冲突需要修改

class BookView(ModelViewSet):
    queryset = models.Book.objects.all()
    serializer_class = serializer.BookSerializer
'''路由'''
router = SimpleRouter()
router.register('books', views.BookView, 'books')

urlpatterns = [
    path('admin/', admin.site.urls),
    path('api/v1/',include(router.urls)),
]

视图集中定义附加action动作#

在视图集中，除了上述默认的方法动作外，还可以添加自定义动作。

from rest_framework.viewsets import ModelViewSet,ReadOnlyModelViewSet
class StudentModelViewSet(ModelViewSet):
    queryset = Student.objects.all()
    serializer_class = StudentModelSerializer

    def login(self,request):
        """学生登录功能"""
        return Response({"message":"登录成功"})

url的定义

urlpatterns = [
    path("students8/", views.StudentModelViewSet.as_view({"get": "list", "post": "create"})),
    re_path("students8/(?P<pk>\d+)/",
            views.StudentModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})),

    path("stu/login/",views.StudentModelViewSet.as_view({"get":"login"}))

]

action属性#

在视图集中，我们可以通过action对象属性来获取当前请求视图集时的action动作是哪个。

from rest_framework.viewsets import ModelViewSet
from students.models import Student
from .serializers import StudentModelSerializer
from rest_framework.response import Response
class StudentModelViewSet(ModelViewSet):
    queryset = Student.objects.all()
    serializer_class = StudentModelSerializer

    def get_new_5(self,request):
        """获取最近添加的5个学生信息"""
        # 操作数据库
        print(self.action) # 获取本次请求的视图方法名
        
        
通过路由访问到当前方法中.可以看到本次的action就是请求的方法名

累死🐵，有错误请指正~感谢

DRF 视图组件 - HammerZe