（生鲜项目）08. ModelSerializer 实现商品列表页, 使用Mixin来实现返回, 以及更加方便的ListAPIView, 以及分页的设置

from rest_framework import serializers

from goods.models import Goods, GoodsCategory


# 让goods的category字段全量显示
class CategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = GoodsCategory
        fields = "__all__"  # 取所有字段

# 方式一
# class GoodsSerializer(serializers.Serializer):
#     name = serializers.CharField(required=True, max_length=100)
#     click_num = serializers.IntegerField(default=0)
#     goods_front_image=serializers.ImageField()

# 方式二: 用ModelSerializer
class GoodsSerializer(serializers.ModelSerializer):
    category = CategorySerializer()  # 重写category字段,从而实现ModelSerializer的嵌套

    class Meta:
        model = Goods
        # fields = ("name", "click_num", "market_price", "add_time")
        fields = "__all__"  # 取所有字段

from rest_framework import mixins
from rest_framework import generics
from rest_framework.views import APIView
from rest_framework.response import Response

from .models import Goods
from .serializers import GoodsSerializer


# # 方式一, APIview继承了View
# class GoodsListView(APIView):
#     """
#     List all snippets, or create a new snippet.
#     """
#
#     def get(self, request, format=None):
#         goods = Goods.objects.all()[:10]
#         goods_serializer = GoodsSerializer(goods, many=True)  # many:是否是querrySet对象
#         return Response(goods_serializer.data)

# # 方式二: 利用mixins.ListModelMixin, generics.GenericAPIView
# class GoodsListView(mixins.ListModelMixin, generics.GenericAPIView):
#     """
#     商品列表页
#     """
#     queryset = Goods.objects.all()[:10]
#     serializer_class = GoodsSerializer
#
#     def get(self, request, *args, **kwargs):
#         return self.list(request, *args, **kwargs)


# # 方式三,使用更加简便的generics.ListAPIView
# # 原理就是: ListAPIView里面继承了mixins.ListModelMixin, generics.GenericAPIView, 而且还封装了返回
class GoodsListView(generics.ListAPIView):
    """
    商品列表页
    """
    queryset = Goods.objects.all()
    serializer_class = GoodsSerializer

REST_FRAMEWORK = {
    # 解决 1.11.3版本下使用APIview会报‘CSRFCheck‘ object has no attribute ‘process_request‘的问题
    # "DEFAULT_AUTHENTICATION_CLASSES": [],
    
    ‘DEFAULT_PAGINATION_CLASS‘: ‘rest_framework.pagination.PageNumberPagination‘,
    ‘PAGE_SIZE‘: 10,
}

from rest_framework import mixins
from rest_framework import generics
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination  # 自定义分页

from .models import Goods
from .serializers import GoodsSerializer

# 自定义分页功能, 并实现动态分页, 继承PageNumberPagination
class GoodsPagination(PageNumberPagination):
    page_size = 10
    page_size_query_param = ‘page_size‘  # 指定每一页显示多少条
    page_query_param = "p"  # 指定要第几页
    max_page_size = 100


class GoodsListView(generics.ListAPIView):
    """
    商品列表页
    """
    queryset = Goods.objects.all()
    serializer_class = GoodsSerializer
    pagination_class = GoodsPagination  # 需要指定分页的类