drf知识--05

两个视图基类

# APIView：之前一直在用---》drf提供的最顶层的父类---》以后所有视图类，都继承自它
# GenericAPIView：继承自APIView--》封装

继承APIView+序列化类+Response写接口

# urls.py--总路由
from django.contrib import admin
from django.urls import path,include
from app01 import views
urlpatterns = [
    path('admin/', admin.site.urls),
    path('app/',include('app01.urls'))]

# urls.py--子路由app01
from django.contrib import admin
from django.urls import path, include
from . import views
urlpatterns = [
    path('books/', views.BookView.as_view()),
    path('books/', views.BookDetailView.as_view()),]

# 序列化类
from rest_framework import serializers
from .models import Book

class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model = Book
        fields = ['id', 'name', 'price', 'publish', 'authors', 'publish_detail', 'author_list']
        extra_kwargs = {
            'publish': {'write_only': True},
            'authors': {'write_only': True},
            'publish_detail': {'read_only': True},
            'author_list': {'read_only': True},
        }

# models.py
from django.db import models


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

    @property
    def author_list(self):
        l = []
        for author in self.authors.all():
            l.append({'name': author.name, 'age': author.age})
        return l

    def __str__(self):
        return self.name

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

class AuthorDetail(models.Model):
    telephone = models.BigIntegerField()
    birthday = models.DateField()
    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()
    def __str__(self):
        return self.name
    class Meta:
        verbose_name = '出版社'
        verbose_name_plural = verbose_name

# views.py
class BookView(APIView):
    def get(self, request):
        book_list = Book.objects.all()
        ser = BookSerializer(instance=book_list, many=True)
        return Response(ser.data)

    def post(self, request):
        ser = BookSerializer(data=request.data)
        if ser.is_valid():
            ser.save()
            return Response(ser.data)
        else:
            return Response(ser.errors)


class BookDetailView(APIView):
    def put(self, request, *args, **kwargs):
        book = Book.objects.filter(pk=kwargs.get('pk')).first()
        ser = BookSerializer(instance=book, data=request.data)
        if ser.is_valid():
            ser.save()
            return Response(ser.data)
        else:
            return Response(ser.errors)

    def get(self, request, *args, **kwargs):
        book = Book.objects.filter(pk=kwargs.get('pk')).first()
        ser = BookSerializer(instance=book)
        return Response(ser.data)

    def delete(self, request, *args, **kwargs):
        Book.objects.filter(pk=kwargs.get('pk')).delete()
        return Response('')

继承GenericAPIView+序列化类+Response写接口

# 继承GenericAPIView的写法
    -1 在类中，写两个类属性：所有数据，序列化类
        queryset = Book.objects.all()
        serializer_class = BookSerializer
    -2 获取所有要序列化的数据:
        self.get_queryset()
    -3 获取序列化类
        self.get_serializer(参数跟之前一样)
    -4 获取单挑
        self.get_object()
# 如果想快速写出Publish的5个接口，只需要修改视图类上的两个类属性即可
        queryset = Publish.objects.all()
        serializer_class = PublishSerializer
# GenericAPIView源码分析:
   1 继承了APIView
   2 有些类属性--》目前只记住两个queryset，serializer_class

queryset            # 要序列化的所有数据
serializer_class    # 序列化类
lookup_field = 'pk' # 查询单条，前端传入的参数对应值【pk】，转换器
filter_backends     # 后续要学的，过滤
pagination_class    # 后续要学的，分页

   3 有些对象方法
get_queryset： 返回待序列化的数据
      调用 .all ，在子类中重写，控制要序列化的数据
get_serializer： 返回 序列化类  以后用它
      本质就是 self.serializer_class(instance=object_list, many=True) 
      内部调用了：self.get_serializer_class
      后期可在子类中重写get_serializer_class，返回什么序列化类就以哪个序列化类做序列化

get_object：获取单条，根据它：lookup_field   获取

get_serializer_class 它是用来重写的
def get_serializer_class(self):
      if self.request.method=='GET':
          return '序列化的类'
      else:
          return '反序列化的类'

# 对象属性查找顺序：

             在类中定义了属性，对象中放入了属性
             self.属性  用的对象自己的，如果对象中没放：self.属性用了类的

# 总结：

# urls.py
urlpatterns = [
    path('books/', views.BookView.as_view()),
    path('books/', views.BookDetailView.as_view()),

    path('publish/', views.PublishView.as_view()),
    path('publish/', views.PublishDetailView.as_view()),
]

# serializer.py
class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model = Book
        fields = ['id', 'name', 'price', 'publish', 'authors', 'publish_detail', 'author_list']
        extra_kwargs = {
            'publish': {'write_only': True},
            'authors': {'write_only': True},
            'publish_detail': {'read_only': True},
            'author_list': {'read_only': True},
        }
class PublishSerializer(serializers.ModelSerializer):
    class Meta:
        model = Publish
        fields = "__all__"

# views.py
from rest_framework.generics import GenericAPIView
from .models import Publish
from .serializer import PublishSerializer

class BookView(GenericAPIView):
    queryset = Book.objects.all()
    serializer_class = BookSerializer
    def get(self, request):
        object_list = self.get_queryset()  # 获取所有要序列化的数据
        ser = self.get_serializer(instance=object_list, many=True)  # 获取序列化类
        return Response(ser.data)

    def post(self, request):
        ser = self.get_serializer(data=request.data)
        if ser.is_valid():
            ser.save()
            return Response(ser.data)
        else:
            return Response(ser.errors)

class BookDetailView(GenericAPIView):
    queryset = Book.objects.all()
    serializer_class = BookSerializer
    def put(self, request, *args, **kwargs):
        obj = self.get_object()  # 获取单挑---》内部就是按pk从request中取，取出pk对应的值，查询的
        ser = self.get_serializer(instance=obj, data=request.data)
        if ser.is_valid():
            ser.save()
            return Response(ser.data)
        else:
            return Response(ser.errors)

    def get(self, request, *args, **kwargs):
        obj = self.get_object()
        ser = self.get_serializer(instance=obj)
        return Response(ser.data)

    def delete(self, request, *args, **kwargs):
        self.get_object().delete()
        return Response('')

5个视图扩展类

# 继承 GenericAPIView+5个视图扩展类+序列化类+Response

# views.py
from rest_framework.mixins import CreateModelMixin, ListModelMixin, RetrieveModelMixin, UpdateModelMixin, \
    DestroyModelMixin

class BookView(GenericAPIView, CreateModelMixin, ListModelMixin):
    queryset = Book.objects.all()
    serializer_class = BookSerializer
    def get(self, request):
        return super().list(request)
    def post(self, request):
        # 做保存，加了这一句---》目的是：子类可以重写,增强扩展性
        # self.perform_create(serializer)
        return super().create(request)

class BookDetailView(GenericAPIView, RetrieveModelMixin, DestroyModelMixin, UpdateModelMixin):
    queryset = Book.objects.all()
    serializer_class = BookSerializer
    def put(self, request, *args, **kwargs):
        return super().update(request, *args, **kwargs)

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

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

9个视图子类

# CreateAPIView继承了 GenericAPIView, CreateModelMixin，写了post方法

views.py
from rest_framework.generics import CreateAPIView, ListAPIView
from rest_framework.generics import RetrieveAPIView, DestroyAPIView, UpdateAPIView
from rest_framework.generics import ListCreateAPIView
from rest_framework.generics import RetrieveUpdateDestroyAPIView, RetrieveDestroyAPIView, RetrieveUpdateAPIView
# from rest_framework.generics import DestroyUpdateAPIView # 一般不存在，所以就没有

# 实现新增,查所有和查询一条
class BookView(ListCreateAPIView):
    # 配置两个类属性
    queryset = Book.objects.all()
    serializer_class = BookSerializer

class BookDetailView(RetrieveAPIView):
    queryset = Book.objects.all()
    serializer_class = BookSerializer

视图集

# views.py
from rest_framework.viewsets import ModelViewSet
class BookView(ModelViewSet):
    queryset = Book.objects.all()
    serializer_class = BookSerializer

urls.py
path('books/', views.BookView.as_view({'get':'list','post':'create'})),
path('books/', views.BookView.as_view({'get':'retrieve','put':'update','delete':'destroy'})),

今日思维导图：