【愚公系列】2022年04月 Python教学课程 68-DRF框架之五个扩展类视图

class ListModelMixin(object):
    """
    List a queryset.
    """
    def list(self, request, *args, **kwargs):
        # 过滤
        queryset = self.filter_queryset(self.get_queryset())
        # 分页
        page = self.paginate_queryset(queryset)
        if page is not None:
            serializer = self.get_serializer(page, many=True)
            return self.get_paginated_response(serializer.data)
        # 序列化
        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)

class CreateModelMixin(object):
    """
    Create a model instance.
    """
    def create(self, request, *args, **kwargs):
        # 获取序列化器
        serializer = self.get_serializer(data=request.data)
        # 验证
        serializer.is_valid(raise_exception=True)
        # 保存
        self.perform_create(serializer)
        headers = self.get_success_headers(serializer.data)
        return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)

    def perform_create(self, serializer):
        serializer.save()

    def get_success_headers(self, data):
        try:
            return {'Location': str(data[api_settings.URL_FIELD_NAME])}
        except (TypeError, KeyError):
            return {}

class RetrieveModelMixin(object):
    """
    Retrieve a model instance.
    """
    def retrieve(self, request, *args, **kwargs):
        # 获取对象，会检查对象的权限
        instance = self.get_object()
        # 序列化
        serializer = self.get_serializer(instance)
        return Response(serializer.data)

class UpdateModelMixin(object):
    """
    Update a model instance.
    """
    def update(self, request, *args, **kwargs):
        partial = kwargs.pop('partial', False)
        instance = self.get_object()
        serializer = self.get_serializer(instance, data=request.data, partial=partial)
        serializer.is_valid(raise_exception=True)
        self.perform_update(serializer)

        if getattr(instance, '_prefetched_objects_cache', None):
            # If 'prefetch_related' has been applied to a queryset, we need to
            # forcibly invalidate the prefetch cache on the instance.
            instance._prefetched_objects_cache = {}

        return Response(serializer.data)

    def perform_update(self, serializer):
        serializer.save()

    def partial_update(self, request, *args, **kwargs):
        kwargs['partial'] = True
        return self.update(request, *args, **kwargs)

class DestroyModelMixin(object):
    """
    Destroy a model instance.
    """
    def destroy(self, request, *args, **kwargs):
        instance = self.get_object()
        self.perform_destroy(instance)
        return Response(status=status.HTTP_204_NO_CONTENT)

    def perform_destroy(self, instance):
        instance.delete()

from rest_framework.response import Response
from rest_framework.mixins import ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin,DestroyModelMixin
from rest_framework.generics import GenericAPIView
from book.models import BookInfo
from drf_book.serializer import BookSerializer


class BooksMixinView(ListModelMixin, CreateModelMixin, GenericAPIView):
    """
        获取所有图书和保存图书
    """
    # 指定查询集属性
    queryset = BookInfo.objects.all()
    # 指定序列化器
    serializer_class = BookSerializer

    def get(self, request):
        """
            获取所有图书
        :param request:
        :return:
        """
        return self.list(request)

    def post(self, request):
        """
            保存图书
        :param request:
        :return:
        """
        return self.create(request)


class BookMixinView(RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin, GenericAPIView):
    """
           获取单一图书数据
           更新图书
           删除图书
       """
    # 指定查询集属性
    queryset = BookInfo.objects.all()
    # 指定序列化器
    serializer_class = BookSerializer

    def get(self, request, pk):
        """
        获取单一图书数据
        :param request:
        :param pk:
        :return:
        """
        return self.retrieve(request)

    def put(self, request, pk):
        """
         更新图书
        :param request:
        :param pk:
        :return:
        """
        return self.update(request)

    def delete(self, request, pk):
        """
        删除图书
        :param request:
        :param pk:
        :return:
        """
        return self.destroy(request)