視圖類與序列化類傳參 視圖家族

視圖類傳遞參數給序列化類

　　在視圖類中實例化序列化對象時，能夠設置context內容，在序列化類中的局部鉤子、全局鉤子、create、update方法中，均可以用self.context訪問視圖類傳遞過來的內容。

需求：

　　在視圖類中，能夠經過request獲得登錄用戶request.user

　　在序列化類中，要完成數據庫數據的校驗與入庫操做，可能會須要知道當前的登錄用戶，但序列化類沒法訪問request

　　在視圖類中實例化序列化對象時，將request對象傳遞進去

序列化層：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

視圖層：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
        })

二次封裝Response類

Response({
    'status': 0,
    'msg': 'ok',
    'results': [],
    'token': ''  # 有這樣的額外的key-value數據結果
},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的初始狀態：狀態碼與狀態信息
        data = {
            'status': data_status,
            'msg': data_msg,
        }
        # data的響應數據體
        # results多是False、0等數據，這些數據某些狀況下也會做爲合法數據返回
        if results is not None:
            data['results'] = results
        # data響應的其餘內容
        # 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)

視圖家族

　　views：視圖　　generics：工具視圖　　mixins：視圖工具集　　viewsets：視圖集

GenericAPIView基類

　　get_queryset()：從類屬性queryset中得到model的queryset數據

　　get_object()：從類屬性queryset中得到model的queryset數據，再經過有名分組pk肯定惟一操做對象

　　get_serializer()：從類屬性serializer_class中得到serializer的序列化類

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
    # 自定義主鍵的 有名分組 名
    lookup_field = 'pk'
    # 羣取
    # 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)

    # 單取
    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視圖工具集 - 輔助GenericAPIView

　　mixins有五個工具類文件，一共提供了五個工具類，六個工具方法：單查、羣查、單增、單刪、單總體改、單局部改.

　　繼承工具類能夠簡化請求函數的實現體，可是必須繼承GenericAPIView，須要GenericAPIView類提供的幾個類屬性和方法(見上方GenericAPIView基類知識點)

　　工具類的工具方法返回值都是Response類型對象，若是要格式化數據格式再返回給前臺，能夠經過 response.data 拿到工具方法返回的Response類型對象的響應數據

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方法的響應對象是Response，想將該對象格式化爲APIResponse
            response = self.list(request, *args, **kwargs)
        # response的數據都存放在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)

工具視圖

　　工具視圖都是GenericAPIView的子類，且不一樣的子類繼承了不一樣的工具類，重寫了請求方法

　　工具視圖的功能若是直接能夠知足需求，只須要繼承工具視圖，提供queryset與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

視圖集

　　視圖集都是優先繼承ViewSetMixin類，再繼承一個視圖類（GenericAPIView或APIView），GenericViewSet、ViewSet

　　ViewSetMixin提供了重寫的as_view()方法，繼承視圖集的視圖類，配置路由時調用as_view()必須傳入 請求名-函數名 映射關係字典， eg: url(r'^v5/books/$', views.BookGenericViewSet.as_view({'get': 'my_get_list'})),  表示get請求會交給my_get_list視圖函數處理

settings.py文件

urlpatterns = [
    # View的as_view()：將get請求映射到視圖類的get方法
    # ViewSet的as_view({'get': 'my_get_list'})：將get請求映射到視圖類的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 與 APIView 最爲兩大繼承視圖的區別

　　GenericViewSet和ViewSet都繼承了ViewSetMixin，as_view均可以配置 請求-函數 映射

　　GenericViewSet繼承的是GenericAPIView視圖類，用來完成標準的 model 類操做接口

　　ViewSet繼承的是APIView視圖類，用來完成不須要 model 類參與，或是非標準的 model 類操做接口， post請求在標準的 model 類操做下就是新增接口，登錄的post不知足， post請求驗證碼的接口，不須要 model 類的參與， 

工具視圖集

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

    # 刪不是數據庫，而是該記錄中的刪除字段
    def destroy(self, request, *args, **kwargs):
        instance = self.get_object()  # type: models.Book
        if not instance:
            return APIResponse(1, '刪除失敗')  # 實際操做，在此以前就作了判斷
        instance.is_delete = True
        instance.save()
        return APIResponse(0, '刪除成功')