（项目）生鲜超市（九）

十、购物车，订单管理和支付功能

1、购物车功能

　　在trade/serializers.py中编写购物车序列化的代码：

 1 class ShopCartSerialzier(serializers.Serializer):
 2     user = serializers.HiddenField(
 3         default=serializers.CurrentUserDefault()
 4     )
 5     nums = serializers.IntegerField(required=True, label='数量', min_value=1,
 6                                     error_messages={
 7                                         "min_value": "商品数量不能小于一",
 8                                         "required": "请选择购买数量"
 9                                     })
10     # goods是一个外键，可以通过这方法获取goods object中所有的值 Serializer必须指定queryset对象，ModelSerializer不需要指定
11     goods = serializers.PrimaryKeyRelatedField(required=True, queryset=Goods.objects.all())
12 
13     # Serializer没有save方法，必须重写create方法
14     def create(self, validated_data):  # validated_data是已经处理过的数据
15         # 获取当前用户，view中获取用户self.request.user serializer中获取用户self.context["request"].user
16         user = self.context["request"].user
17         nums = validated_data["nums"]
18         goods = validated_data["goods"]
19 
20         existed = ShoppingCart.objects.filter(user=user, goods=goods)
21         # 购物车有记录，数量+nums
22         if existed:
23             existed = existed[0]
24             existed.nums += nums
25             existed.save()
26         else:
27             # 没有记录，添加到购物车
28             existed = ShoppingCart.objects.create(**validated_data)
29 
30         return existed
31 
32     # Serializer没有update方法，所以重写Update方法， 添加购物车数量
33     def update(self, instance, validated_data):
34         # 修改商品数量
35         instance.nums = validated_data["nums"]
36         instance.save()
37         return instance

　　在trade/views.py中编写购物车接口：

 1 class ShoppingCartViewSet(viewsets.ModelViewSet):
 2     """
 3     购物车功能
 4     list:
 5         获取购物车详情
 6     create：
 7         加入购物车
 8     delete：
 9         删除购物记录
10     """
11 
12     permission_classes = (IsAuthenticated, IsOwnerOrReadOnly)
13     authentication_classes = (JSONWebTokenAuthentication, SessionAuthentication)
14     serializer_class = ShopCartSerialzier
15 
16     # 把商品id传回去
17     lookup_field = 'goods_id'
18 
19     def get_queryset(self):
20         return ShoppingCart.objects.filter(user=self.request.user)

　　注册url：

1 router.register(r'shopcarts', ShoppingCartViewSet, base_name='shopcarts')  # 购物车

　　购物车中可以看商品详情，需要写一个商品详情的serializer，在view中需要动态设置serializer：

1 class ShopCartDetailSerializer(serializers.ModelSerializer):
2     # 一个购物车对应一个商品
3     goods = GoodsSerializer(many=False, read_only=True)
4     class Meta:
5         model = ShoppingCart
6         fields = ('goods', 'nums')

　　完善购物车接口，动态选择serializer：

 1 class ShoppingCartViewSet(viewsets.ModelViewSet):
 2     """
 3     购物车功能
 4     list:
 5         获取购物车详情
 6     create：
 7         加入购物车
 8     delete：
 9         删除购物记录
10     """
11 
12     permission_classes = (IsAuthenticated, IsOwnerOrReadOnly)
13     authentication_classes = (JSONWebTokenAuthentication, SessionAuthentication)
14 
15     # 把商品id传回去
16     lookup_field = 'goods_id'
17 
18     def get_serializer_class(self):
19         if self.action == 'list':
20             return ShopCartDetailSerializer
21         else:
22             return ShopCartSerializer
23 
24     def get_queryset(self):
25         return ShoppingCart.objects.filter(user=self.request.user)

2、订单功能

　　用户添加商品到购物车，点击购物车结算，填上地址留言，结算生成订单，在会员中心我的订单里面，可以看到订单列表，点订单可以看到订单的详细信息，首先完成订单的序列化：

 1 class OrderGoodsSerializer(serializers.ModelSerializer):
 2     # 订单内的商品
 3     goods = GoodsSerializer(many=False)
 4 
 5     class Meta:
 6         model = OrderGoods
 7         fields = "__all__"
 8 
 9 
10 class OrderDetailSerializer(serializers.ModelSerializer):
11     # goods字段需要嵌套一个OrderGoodsSerializer
12     goods = OrderGoodsSerializer(many=True)
13 
14     class Meta:
15         model = OrderInfo
16         fields = "__all__"
17 
18 
19 class OrderSerializer(serializers.ModelSerializer):
20     user = serializers.HiddenField(
21         default=serializers.CurrentUserDefault()
22     )
23     # 生成订单的时候这些不用post
24     pay_status = serializers.CharField(read_only=True)
25     trade_no = serializers.CharField(read_only=True)
26     order_sn = serializers.CharField(read_only=True)
27     pay_time = serializers.DateTimeField(read_only=True)
28     nonce_str = serializers.CharField(read_only=True)
29     pay_type = serializers.CharField(read_only=True)
30 
31     # 生成订单号
32     def generate_order_sn(self):
33         # 格式：当前时间+userid+随机数
34         random_ins = Random()
35         order_sn = '{time_str}{userid}{ranstr}'.format(time_str=time.strftime("%Y%m%d%H%M%S"),
36                                                        userid=self.context["request"].user.id,
37                                                        ranstr=random_ins.randint(10, 99))
38         return order_sn
39 
40     def validate(self, attrs):
41         # validate中添加order_sn，然后在view中就可以save
42         attrs['order_sn'] = self.generate_order_sn()
43         return attrs
44 
45     class Meta:
46         model = OrderInfo
47         fields = "__all__"

　　在views.py中完成订单的接口：

 1 class OrderViewSet(mixins.ListModelMixin, mixins.RetrieveModelMixin, mixins.CreateModelMixin, mixins.DestroyModelMixin,
 2                    viewsets.GenericViewSet):
 3     """
 4     订单管理
 5     list:
 6         获取个人订单
 7     delete:
 8         删除订单
 9     create：
10         新增订单
11     """
12 
13     permission_classes = (IsAuthenticated, IsOwnerOrReadOnly)
14     authentication_classes = (JSONWebTokenAuthentication, SessionAuthentication)
15 
16     def get_serializer_class(self):
17         if self.action == "retrieve":
18             return OrderDetailSerializer
19         return OrderSerializer
20 
21     def get_queryset(self):
22         return OrderInfo.objects.filter(user=self.request.user)
23 
24     # 在提交订单还需要将购物车中的商品保存到OrderGoods中，然后清空购物车
25     def perform_create(self, serializer):
26         order = serializer.save()
27 
28         # 获取购物车中的所有商品，将商品添加到订单中
29         shop_carts = ShoppingCart.objects.filter(user=self.request.user)
30         for shop_cart in shop_carts:
31             order_goods = OrderGoods()
32             order_goods.goods = shop_cart.goods
33             order_goods.goods_num = shop_cart.nums
34             order_goods.order = order
35             order_goods.save()
36 
37             # 清空购物车
38             shop_cart.delete()
39 
40         return order

　　注册url：

1 router.register(r'orders', OrderViewSet, base_name='orders')  # 订单

　　不要忘了修改Vue中的host，然后在前端测试添加商品到购物车，然后点击结算生成订单，在个人中心新中有订单信息。

转载于:https://www.cnblogs.com/Sweltering/p/10029670.html