rest_framework中视图相关

模型类的定义

# 定义图书模型类BookInfo
class BookInfo(models.Model):
    btitle = models.CharField(max_length=20, verbose_name='名称')
    bpub_date = models.DateField(verbose_name='发布日期')
    bread = models.IntegerField(default=0, verbose_name='阅读量')
    bcomment = models.IntegerField(default=0, verbose_name='评论量')
    is_delete = models.BooleanField(default=False, verbose_name='逻辑删除')

    class Meta:
        db_table = 'tb_books'  # 指明数据库表名
        verbose_name = '图书'  # 在admin站点中显示的名称
        verbose_name_plural = verbose_name  # 显示的复数名称

    def __str__(self):
        """定义每个数据对象的显示信息"""
        return self.btitle

定义一个序列化器

from rest_framework import serializers  # 引入类

class BookInfoSerializer(serializers.Serializer):
    """ 图书列表序列化器"""
    id = serializers.IntegerField(label="ID", read_only=True)
    btitle = serializers.CharField(label="名称", max_length=20)
    bpub_date = serializers.DateField(label='发布日期', required=False)
    bread = serializers.IntegerField(label='阅读量', required=False)
    bcomment = serializers.IntegerField(label='评论量', required=False)
    is_delete = serializers.BooleanField(label='逻辑删除', required=False)
    heroinfo_set = serializers.PrimaryKeyRelatedField(read_only=True, many=True)  # 新增

    def create(self, validated_data):
        """新建"""
        return BookInfo.objects.create(**validated_data)

    def update(self, instance, validated_data):
        """更新，instance为要更新的对象实例"""
        instance.btitle = validated_data.get('btitle', instance.btitle)
        instance.bpub_date = validated_data.get('bpub_date', instance.bpub_date)
        instance.bread = validated_data.get('bread', instance.bread)
        instance.bcomment = validated_data.get('bcomment', instance.bcomment)
        instance.save()
        return instance

django本身的View类来构建一个RESTful风格的API接口的开发；

import json
from django.forms import model_to_dict
from django.http import JsonResponse
from django.shortcuts import HttpResponse
from django.views import View
from rest_framework.viewsets import ModelViewSet

from .models import BookInfo

class BooksAPIView(View):
    def get(self, request):
        """
        查询所有图书
        :param request:
        :return:
        """
        queryset = BookInfo.objects.all().values()
        book_list = []
        book_list = list(queryset)

        return JsonResponse(book_list, safe=False)

    def post(self, request):
        """
        新增图书
        :param request:
        :return:
        """
        json_bytes = request.body
        json_str = json_bytes.decode()
        book_dict = json.loads(json_str)
        book = BookInfo.objects.create(
            **book_dict
        )

        return JsonResponse({
            "id": book.id,
            "btitle": book.btitle,
            'bpub_date': book.bpub_date,
            'bread': book.bread,
            'bcomment': book.bcomment,
        }, status=201)

class BookAPIView(View):
    """
    获取单个图书的信息
    """

    def get(self, request, pk):
        try:
            book = BookInfo.objects.get(id=pk)
        except Exception as e:
            print(e)
            return HttpResponse(status=404)

        book_dict = model_to_dict(book)
        return JsonResponse(book_dict)

    def put(self, request, pk):
        """
        修改图书信息
        :param request:
        :param pk:
        :return:
        """
        try:
            book = BookInfo.objects.get(id=pk)
        except Exception as e:
            print(e)
            return HttpResponse(status=404)

        # 校验参数

        json_bytes = request.body
        json_str = json_bytes.decode()
        book_dict = json.loads(json_str)

        BookInfo.objects.filter(id=pk).update(**book_dict)
        book_dict = model_to_dict(BookInfo.objects.get(id=pk))
        return JsonResponse(book_dict)

    def delete(self, request, pk):
        """
        删除
        :param request:
        :param pk:
        :return:
        """
        try:
            book = BookInfo.objects.get(id=pk)
        except Exception as e:
            print(e)
            return HttpResponse(status=404)

        book.delete()
        return HttpResponse(status=204)

"""
urlpatterns = [
    url(r'^books/$', views.BooksAPIView.as_view()),
    url(r'^books/(?P<pk>\d+)/$', views.BookDetailView.as_view()),
]
"""

通过（from rest_framework.views import APIView）中的APIView类构建一个RESTful风格的API接口的开发；

from .models import BookInfo

from .serializers import BookInfoSerializer
from rest_framework.views import APIView
from rest_framework.response import Response

class BooksAPIView(APIView):
    """
    与django中的view相比
    """

    def get(self, request):
        # 数据库中取数据；
        books = BookInfo.objects.all()
        # 序列化器的使用；
        serializer = BookInfoSerializer(books, many=True)
        # 返回数据
        return Response(serializer.data)

"""
from app001 import views
urlpatterns = [
    url(r'^books/$', views.BooksAPIView.as_view()),
]
"""

"""
此时继承的APIView与django中的view比较；
1,传入到视图方法中的是REST framework的Request对象，而不是Django的HttpRequeset对象；
2,视图方法可以返回REST framework的Response对象，视图会为响应数据设置（render）符合前端要求的格式；
3,任何APIException异常都会被捕获到，并且处理成合适的响应信息；
4,在进行dispatch()分发前，会对请求进行身份认证、权限检查、流量控制。
"""

通过APIView的子类GenericAPIView子类构建一个RESTful风格的API接口的开发；

from .models import BookInfo
from .serializers import BookInfoSerializer
from rest_framework.response import Response
from rest_framework.generics import GenericAPIView

class BooksAPIView(GenericAPIView):
    """
    与restframework中的APIView相比
    """
    # 取出queryset对象
    queryset = BookInfo.objects.all()
    # 定义一个序列化器的类
    serializer_class = BookInfoSerializer

    def get(self, request):
        # 数据库中取数据；
        qs = self.get_queryset()
        # 序列化器的使用；
        serializer = self.get_serializer(qs, many=True)
        # 返回数据
        return Response(serializer.data)

class BookDetailView(GenericAPIView):
    # 取出queryset对象
    queryset = BookInfo.objects.all()
    # 定义一个序列化器的类
    serializer_class = BookInfoSerializer

    def get(self, request, pk):
        # 数据库中取数据；
        qs = self.get_object()
        # 序列化器的使用；
        serializer = self.get_serializer(qs)
        # 返回数据
        return Response(serializer.data)

"""
from app001 import views
urlpatterns = [
    url(r'^books/$', views.BooksAPIView.as_view()),
    url(r'^books/(?P<pk>\d+)/$', views.BookDetailView.as_view()),
]
"""

"""
获取多个对象时候使用的方法（ qs = self.get_queryset()）
1，在这个视图中需要自己传入要返回的queryset对象；
2，要传来做序列化的类；
3，在定义的具体方法中来使用self.get_queryset()来获取类中的对象；
4，获取序列化的类然后处理数据；
5，将处理后的类返回到接口中；

获取单个对象使用的方法（qs = self.get_object()）
步骤类似

总结：
在GenericAPIView的类中继承需要自己指定模型类；
自己指定方法的映射关系；
自己取对象；
自己取序列化的类；
自己返回数据
"""

（from rest_framework.generics import GenericAPIView）（from rest_framework import mixins）通过这两个子类构建一个RESTful风格的API接口的开发；

from .models import BookInfo
from .serializers import BookInfoSerializer
from rest_framework.generics import GenericAPIView
from rest_framework import mixins

class BooksAPIView(mixins.ListModelMixin, GenericAPIView):
    """
    与restframework中的APIView相比
    """
    # 取出queryset对象
    queryset = BookInfo.objects.all()
    # 定义一个序列化器的类
    serializer_class = BookInfoSerializer

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

class BookDetailView(mixins.RetrieveModelMixin, GenericAPIView):
    # 取出queryset对象
    queryset = BookInfo.objects.all()
    # 定义一个序列化器的类
    serializer_class = BookInfoSerializer

    def get(self, request, pk):
        return self.retrieve(request)

"""
from app001 import views
urlpatterns = [
    url(r'^books/$', views.BooksAPIView.as_view()),
    url(r'^books/(?P<pk>\d+)/$', views.BookDetailView.as_view()),
]
"""

"""
总结：
在mixins.RetrieveModelMixin与GenericAPIView相比较；
1，封装(self.get_queryset()的方法；
2，封装了self.paginate_queryset()的方法；
3，封装了serializer = self.get_serializer(queryset, many=True)的方法；
4，将序列化后的结果返回；
"""

（from rest_framework.generics import ListAPIView）类构建一个RESTful风格的API接口的开发；

from .models import BookInfo
from .serializers import BookInfoSerializer
from rest_framework.generics import ListAPIView

class BooksAPIView(ListAPIView):
    # 取出queryset对象
    queryset = BookInfo.objects.all()
    # 定义一个序列化器的类
    serializer_class = BookInfoSerializer

from rest_framework.generics import RetrieveAPIView

class BookDetailView(RetrieveAPIView):
    # 取出queryset对象
    queryset = BookInfo.objects.all()
    # 定义一个序列化器的类
    serializer_class = BookInfoSerializer

"""
from app001 import views
urlpatterns = [
    url(r'^books/$', views.BooksAPIView.as_view()),
    url(r'^books/(?P<pk>\d+)/$', views.BookDetailView.as_view()),
]
"""

"""
总结：
from rest_framework.generics import GenericAPIView
from rest_framework import mixins
等价与
from rest_framework.generics import ListAPIView

调用方式；
在get的方法中指明要调用的类中的封装的方法；
"""

（from rest_framework.viewsets import GenericViewSet）类构建一个RESTful风格的API接口的开发；

from .models import BookInfo
from .serializers import BookInfoSerializer
from rest_framework import mixins
from rest_framework.viewsets import GenericViewSet

class BooksAPIViewSet(mixins.ListModelMixin,mixins.RetrieveModelMixin,GenericViewSet):
    """
    mixins.ListModelMixin:实现了list的函数；
   GenericViewSet(ViewSetMixin, generics.GenericAPIView):
        ViewSetMixin 重写了as_view的方法（在url中将请求方式和action对应    queryset,serializer_class两个参数）；
        GenericAPIView(views.APIView) 实现了get_queryset()和get_object的方法:
    """
    # 取出queryset对象
    queryset = BookInfo.objects.all()
    # 定义一个序列化器的类
    serializer_class = BookInfoSerializer

"""
url的访问形式
urlpatterns = [
    url(r'^books/$', views.BooksAPIViewSet.as_view({"get": "list"})),
    url(r'^books/(?P<pk>\d+)/$', views.BooksAPIViewSet.as_view({"get": "retrieve"})),
]
"""

"""
总结：
from rest_framework.generics import GenericAPIView
from rest_framework import mixins
等价与
from rest_framework.generics import ListAPIView
"""

action自定义方法扩张类构建一个RESTful风格的API接口的开发；

from .models import BookInfo
from .serializers import BookInfoSerializer
from rest_framework.viewsets import ModelViewSet
from rest_framework.decorators import action
from rest_framework.response import Response

class BookInfoViewSet(ModelViewSet):
    # 取出queryset对象
    queryset = BookInfo.objects.all()
    # 定义一个序列化器的类
    serializer_class = BookInfoSerializer

    # detail为False 表示不需要处理具体的BookInfo对象
    @action(methods=['get'], detail=False)
    def latest(self, request):
        """
        返回最新的图书信息
        """
        book = BookInfo.objects.latest('id')
        serializer = self.get_serializer(book)
        return Response(serializer.data)

    # detail为True，表示要处理具体与pk主键对应的BookInfo对象
    @action(methods=['put'], detail=True)
    def read(self, request, pk):
        """
        修改图书的阅读量数据
        """
        book = self.get_object()
        book.bread = request.data.get('read')
        book.save()
        serializer = self.get_serializer(book)
        return Response(serializer.data)

"""
url的访问形式
urlpatterns = [
    url(r'^books/$', views.BookInfoViewSet.as_view({'get': 'list'})),
    url(r'^books/latest/$', views.BookInfoViewSet.as_view({'get': 'latest'})),
    url(r'^books/(?P<pk>\d+)/$', views.BookInfoViewSet.as_view({'get': 'retrieve'})),
    url(r'^books/(?P<pk>\d+)/read/$', views.BookInfoViewSet.as_view({'put': 'read'})),
]
"""

"""
总结：
1） ViewSet
继承自APIView，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。

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。

2）GenericViewSet
继承自GenericAPIView，作用也与GenericAPIVIew类似，提供了get_object、get_queryset等方法便于列表视图与详情信息视图的开发。

3）ModelViewSet
继承自GenericAPIVIew，同时包括了ListModelMixin、RetrieveModelMixin、CreateModelMixin、UpdateModelMixin、DestoryModelMixin。

4）ReadOnlyModelViewSet
继承自GenericAPIVIew，同时包括了ListModelMixin、RetrieveModelMixin。
"""