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二次封装 Reponse,视图家族

时间:2019-10-19 23:28:06      阅读:67      评论:0      收藏:0      [点我收藏+]

复习

"""
1、整体修改与局部修改
    # 序列化
    ser_obj = ModelSerializer(model_obj)  
    # 反序列化,save() => create()
    ser_obj = ModelSerializer(data=model_data)  
    # save() => update()
    ser_obj = ModelSerializer(instance=model_obj,data=model_data)  
    # partial=True => 匹配字段required=True校验条件
    ser_obj = ModelSerializer(instance=model_obj,data=model_data,partial=True)
    

2、群改ListSerializer
    ser_obj = ModelSerializer(instance=model_obj,data=model_data,partial=True,many=True)
    
    # 一旦设置了many=True,反序列化情况下的create、update就不再调用ModelSerializer的
    # 而是调用 ModelSerializer.Meta.list_serializer_class 指向的 ListSerializer 类的create、update
    # ListSerializer默认只实现了群增的create,要实现群改,必须重写update
    
    class MyListSerializer(ListSerializer):
        def update(self, instance, validated_data):
            # print(instance)  # 要更新的对象们: [obj1, obj2, ...]
            # print(validated_data)  # 更新的对象对应的数据们: [{}, {}, ...]
            # print(self.child)  # 服务的模型序列化类 - V2BookModelSerializer
            for index, obj in enumerate(instance):
                self.child.update(obj, validated_data[index])
            return instance
            
     class MyModelSerializer(ModelSerializer):
        class Meta:
            # ...
            list_serializer_class = MyListSerializer
     
     将两者类建立关联,在MyListSerializer中就可以用self.child拿到MyModelSerializer,进而使用MyModelSerializer中封装好的方法
     cls.Meta.list_serializer_class.child = cls
"""

视图类传递参数给序列化类

# 1)在视图类中实例化序列化对象时,可以设置context内容
# 2)在序列化类中的局部钩子、全局钩子、create、update方法中,都可以用self.context访问视图类传递过来的内容


# 需求:
# 1) 在视图类中,可以通过request得到登陆用户request.user
# 2) 在序列化类中,要完成数据库数据的校验与入库操作,可能会需要知道当前的登陆用户,但序列化类无法访问request
# 3) 在视图类中实例化序列化对象时,将request对象传递进去
视图层:views.py
class Book(APIView):
    def post(self, request, *args, **kwargs):
        book_ser = serializers.BookModelSerializer(data=request_data,context={'request':request})
        book_ser.is_valid(raise_exception=True)
        book_result = book_ser.save()
        return Response({
            'status': 0,
            'msg': 'ok',
            'results': serializers.BookModelSerializer(book_result).data
        })
序列化层:serializers.py
class BookModelSerializer(ModelSerializer):
    class Meta:
        model = models.Book
        fields = ('name', 'price')
    def validate_name(self, value):
        print(self.context.get('request').method)
        return value

二次封装Response类

"""
Response({
    'status': 0,
    'msg': 'ok',
    'results': [],
    'token': ''  # 有这样的额外的key-value数据结果
},status=http_status,headers=headers,exception=True|False)

APIResponse() => Response({'status': 0,'msg': 'ok'})
"""
from rest_framework.response import Response

class APIResponse(Response):
    def __init__(self, data_status=0, data_msg='ok', results=None, http_status=None, headers=None, exception=False, **kwargs):
        # data的初始状态:状态码与状态信息
        data = {
            'status': data_status,
            'msg': data_msg,
        }
        # data的响应数据体
        # results可能是False、0等数据,这些数据某些情况下也会作为合法数据返回
        if results is not None:
            data['results'] = results
        # data响应的其他内容
        # if kwargs is not None:
        #     for k, v in kwargs.items():
        #         setattr(data, k, v)
        data.update(kwargs)

        super().__init__(data=data, status=http_status, headers=headers, exception=exception)

视图家族

"""
views: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
"""

GenericAPIView基类

# GenericAPIView是继承APIView的,使用完全兼容APIView
# 重点:GenericAPIView在APIView基础上完成了哪些事
# 1)get_queryset():从类属性queryset中获得model的queryset数据
# 2)get_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
urlpatterns = [
    url(r'^v2/books/$', views.BookGenericAPIView.as_view()),
    url(r'^v2/books/(?P<pk>.*)/$', views.BookGenericAPIView.as_view()),
]
from rest_framework.generics import GenericAPIView
class BookGenericAPIView(GenericAPIView):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer
    # 自定义主键的 有名分组 名
    lookup_field = 'pk'
    # 群取
    # def get(self, request, *args, **kwargs):
    #     book_query = self.get_queryset()
    #     book_ser = self.get_serializer(book_query, many=True)
    #     book_data = book_ser.data
    #     return APIResponse(results=book_data)

    # 单取
    def get(self, request, *args, **kwargs):
        book_query = self.get_object()
        book_ser = self.get_serializer(book_query)
        book_data = book_ser.data
        return APIResponse(results=book_data)

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
# 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)
# 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
urlpatterns = [
    url(r'^v3/books/$', views.BookMixinGenericAPIView.as_view()),
    url(r'^v3/books/(?P<pk>.*)/$', views.BookMixinGenericAPIView.as_view()),
]
from rest_framework.mixins import ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin
class BookMixinGenericAPIView(ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin, GenericAPIView):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer

    def get(self, request, *args, **kwargs):
        if 'pk' in kwargs:
            response = self.retrieve(request, *args, **kwargs)
        else:
            # mixins提供的list方法的响应对象是Response,想将该对象格式化为APIResponse
            response = self.list(request, *args, **kwargs)
        # response的数据都存放在response.data中
        return APIResponse(results=response.data)

    def post(self, request, *args, **kwargs):
        response = self.create(request, *args, **kwargs)
        return APIResponse(results=response.data)

    def put(self, request, *args, **kwargs):
        response = self.update(request, *args, **kwargs)
        return APIResponse(results=response.data)

    def patch(self, request, *args, **kwargs):
        response = self.partial_update(request, *args, **kwargs)
        return APIResponse(results=response.data)

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听的工具类,重写了请求方法
# 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
urlpatterns = [
    url(r'^v4/books/$', views.BookListCreatePIView.as_view()),
    url(r'^v4/books/(?P<pk>.*)/$', views.BookListCreatePIView.as_view()),
]
from rest_framework.generics import ListCreateAPIView, UpdateAPIView
class BookListCreatePIView(ListCreateAPIView, UpdateAPIView):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer

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/$', views.BookGenericViewSet.as_view({'get': 'my_get_list'})),
#       表示get请求会交给my_get_list视图函数处理
urlpatterns = [
    # View的as_view():将get请求映射到视图类的get方法
    # ViewSet的as_view({'get': 'my_get_list'}):将get请求映射到视图类的my_get_list方法
    url(r'^v5/books/$', views.BookGenericViewSet.as_view({'get': 'my_get_list'})),
    url(r'^v5/books/(?P<pk>.*)/$', views.BookGenericViewSet.as_view({'get': 'my_get_obj'})),
]
from rest_framework.viewsets import GenericViewSet
from rest_framework import mixins
class BookGenericViewSet(mixins.RetrieveModelMixin, mixins.ListModelMixin, GenericViewSet):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer

    def my_get_list(self, request, *args, **kwargs):
        return self.list(request, *args, **kwargs)

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

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
# 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

工具视图集

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'})),
]
from rest_framework.viewsets import ModelViewSet
class BookModelViewSet(ModelViewSet):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer

    # 删不是数据库,而是该记录中的删除字段
    def destroy(self, request, *args, **kwargs):
        instance = self.get_object()  # type: models.Book
        if not instance:
            return APIResponse(1, '删除失败')  # 实际操作,在此之前就做了判断
        instance.is_delete = True
        instance.save()
        return APIResponse(0, '删除成功')

路由组件(了解)

from django.conf.urls import include
from rest_framework.routers import SimpleRouter
router = SimpleRouter()
# 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)

二次封装 Reponse,视图家族

原文:https://www.cnblogs.com/DcentMan/p/11706067.html

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