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,可以设置context内容,在序列化类中的局部钩子、全局钩子、create、update方法中,都可以用self.context访问视图类传递过来的内容。
需求:
在视图类中,可以通过request得到登陆用户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
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
GenericAPIView基类
get_queryset():从类属性queryset中获得model的queryset数据
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
get_serializer():从类属性serializer_class中获得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、单整体改、单局部改.
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)
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
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,且不同的子类继承了不同的工具类,重写了请求方法
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
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>.*)/$', views.BookGenericViewSet.as_view({'get': 'my_get_obj'})), ]
views.py
from rest_framework.viewsets import GenericViewSet from rest_framework import mixins class BookGenericViewSet(mixins.RetrieveModelMixin, mixins.ListModelMixin, GenericViewSet): queryset = models.Book.objects.filter(is_delete=False) serializer_class = serializers.BookModelSerializer def my_get_list(self, request, *args, **kwargs): return self.list(request, *args, **kwargs) def my_get_obj(self, request, *args, **kwargs): return self.retrieve(request, *args, **kwargs)
GenericAPIView 与 APIView 最为两大继承视图的区别
GenericViewSet和ViewSet都继承了ViewSetMixin,as_view都可以配置 请求-函数 映射
GenericViewSet继承的是GenericAPIView视图类,用来完成标准的 model 类操作接口
ViewSet继承的是APIView视图类,用来完成不需要 model 类参与,或是非标准的 model 类操作接口, post请求在标准的 model 类操作下就是新增接口,登陆的post不满足, post请求验证码的接口,不需要 model 类的参与,
工具视图集
settings.py文件
urlpatterns = [ url(r'^v6/books/$', 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') # 实际操作,在此之前就做了判断 instance.is_delete = True instance.save() return APIResponse(0, '删除成功')