视图类与序列化类传参 视图家族

视图类传递参数给序列化类

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

需求：

　　在视图类中，能够经过request获得登录用户request.user

　　在序列化类中，要完成数据库数据的校验与入库操做，可能会须要知道当前的登录用户，但序列化类没法访问request

　　在视图类中实例化序列化对象时，将request对象传递进去

序列化层：serializers.py

from rest_framework.serializers import ModelSerializer,SerializerMethodField,ListSerializer
class BookModelSerializer(ModelSerializer):
    class Meta:
        model = models.Book
        fields = {'name','price'}
    def validate_name(self,value):
        print(self.context.get('request').method)
        return value

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
        })

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)

 

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多是False、0等数据，这些数据某些状况下也会做为合法数据返回
        if results is not None:
            data['results'] = results
        # data响应的其余内容
        # 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

GenericAPIView基类

　　get_queryset()：从类属性queryset中得到model的queryset数据

　　get_object()：从类属性queryset中得到model的queryset数据，再经过有名分组pk肯定惟一操做对象

　　get_serializer()：从类属性serializer_class中得到serializer的序列化类

settings.py文件

urlpatterns = [
    url(r'^v2/books/$', views.BookGenericAPIView.as_view()),
    url(r'^v2/books/(?P<pk>.*)/$', views.BookGenericAPIView.as_view()),
]

views.py

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

　　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、单总体改、单局部改.

　　继承工具类能够简化请求函数的实现体，可是必须继承GenericAPIView，须要GenericAPIView类提供的几个类属性和方法(见上方GenericAPIView基类知识点)

　　工具类的工具方法返回值都是Response类型对象，若是要格式化数据格式再返回给前台，能够经过 response.data 拿到工具方法返回的Response类型对象的响应数据

settings.py文件

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

views.py

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

　　工具视图都是GenericAPIView的子类，且不一样的子类继承了不一样的工具类，重写了请求方法

　　工具视图的功能若是直接能够知足需求，只须要继承工具视图，提供queryset与serializer_class便可

settings.py文件

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

views.py

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

　　视图集都是优先继承ViewSetMixin类，再继承一个视图类（GenericAPIView或APIView），GenericViewSet、ViewSet

　　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

settings.py文件

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'})),
]

views.py

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

　　GenericViewSet和ViewSet都继承了ViewSetMixin，as_view均可以配置 请求-函数 映射

　　GenericViewSet继承的是GenericAPIView视图类，用来完成标准的 model 类操做接口

　　ViewSet继承的是APIView视图类，用来完成不须要 model 类参与，或是非标准的 model 类操做接口， post请求在标准的 model 类操做下就是新增接口，登录的post不知足， post请求验证码的接口，不须要 model 类的参与， 

工具视图集

settings.py文件

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'})),
]

views.py

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')  # 实际操做，在此以前就作了判断
        instance.is_delete = True
        instance.save()
        return APIResponse(0, '删除成功')