Django REST framework+Vue 打造生鲜超市（九）
十、购物车、订单管理和支付功能
10.1.添加商品到购物车
（1）trade/serializer.py
# trade/serializer.py
__author__ = 'derek'
from .models import ShoppingCart
from rest_framework import serializers
from goods.models import Goods
class ShopCartSerializer(serializers.Serializer):
#获取当前登录的用户
user = serializers.HiddenField(
default=serializers.CurrentUserDefault()
)
nums = serializers.IntegerField(required=True, label="数量",min_value=1,
error_messages={
"min_value":"商品数量不能小于一",
"required": "请选择购买数量"
})
#这里是继承Serializer，必须指定queryset对象，如果继承ModelSerializer则不需要指定
#goods是一个外键，可以通过这方法获取goods object中所有的值
goods = serializers.PrimaryKeyRelatedField(required=True, queryset=Goods.objects.all())
#继承的Serializer没有save功能，必须写一个create方法
def create(self, validated_data):
# validated_data是已经处理过的数据
#获取当前用户
# view中:self.request.user；serizlizer中:self.context["request"].user
user = self.context["request"].user
nums = validated_data["nums"]
goods = validated_data["goods"]
existed = ShoppingCart.objects.filter(user=user, goods=goods)
#如果购物车中有记录，数量+1
#如果购物车车没有记录，就创建
if existed:
existed = existed[0]
existed.nums += nums
existed.save()
else:
#添加到购物车
existed = ShoppingCart.objects.create(**validated_data)
return existed
（2）trade/views.py
# trade/views.py
from rest_framework import viewsets
from rest_framework.permissions import IsAuthenticated
from utils.permissions import IsOwnerOrReadOnly
from rest_framework_jwt.authentication import JSONWebTokenAuthentication
from rest_framework.authentication import SessionAuthentication
from .serializers import ShopCartSerializer
from .models import ShoppingCart
class ShoppingCartViewset(viewsets.ModelViewSet):
"""
购物车功能
list:
获取购物车详情
create：
加入购物车
delete：
删除购物记录
"""
permission_classes = (IsAuthenticated, IsOwnerOrReadOnly)
authentication_classes = (JSONWebTokenAuthentication, SessionAuthentication)
serializer_class = ShopCartSerializer
def get_queryset(self):
return ShoppingCart.objects.filter(user=self.request.user
（3）配置url
# 配置购物车的url
router.register(r'shopcarts', ShoppingCartViewset, base_name="shopcarts")
10.1.添加购物车数量
Serializer继承BaseSerializer，但是Seriazer中并没有重新update方法，所有添加一个update方法
trade/serializer.py
def update(self, instance, validated_data):
# 修改商品数量
instance.nums = validated_data["nums"]
instance.save()
return instance
在view中要把商品id传过去
lookup_field = "goods_id"
10.3.vue和购物车接口联调
购物车中可以看商品详情，需要写一个商品详情的serializer,所有在view中需要动态设置serializer
（1）trade/serializer.py
class ShopCartDetailSerializer(serializers.ModelSerializer):
'''
购物车商品详情信息
'''
# 一个购物车对应一个商品
goods = GoodsSerializer(many=False, read_only=True)
class Meta:
model = ShoppingCart
fields = ("goods", "nums")
（2）trade/views.py
需要动态选择serializer
def get_serializer_class(self):
if self.action == 'list':
return ShopCartDetailSerializer
else:
return ShopCartSerializer
10.4.订单管理接口
（1）trade/serializer.py
用户添加商品到购物车，点去购物车结算，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。
#订单中的商品
class OrderGoodsSerialzier(serializers.ModelSerializer):
goods = GoodsSerializer(many=False)
class Meta:
model = OrderGoods
fields = "__all__"
#订单商品信息
# goods字段需要嵌套一个OrderGoodsSerializer
class OrderDetailSerializer(serializers.ModelSerializer):
goods = OrderGoodsSerialzier(many=True)
class Meta:
model = OrderInfo
fields = "__all__"
class OrderSerializer(serializers.ModelSerializer):
user = serializers.HiddenField(
default=serializers.CurrentUserDefault()
)
#生成订单的时候这些不用post
pay_status = serializers.CharField(read_only=True)
trade_no = serializers.CharField(read_only=True)
order_sn = serializers.CharField(read_only=True)
pay_time = serializers.DateTimeField(read_only=True)
nonce_str = serializers.CharField(read_only=True)
pay_type = serializers.CharField(read_only=True)
def generate_order_sn(self):
#生成订单号
# 当前时间+userid+随机数
from random import Random
random_ins = Random()
order_sn = "{time_str}{userid}{ranstr}".format(time_str=time.strftime("%Y%m%d%H%M%S"),
userid=self.context["request"].user.id,
ranstr=random_ins.randint(10, 99))
return order_sn
def validate(self, attrs):
#validate中添加order_sn，然后在view中就可以save
attrs["order_sn"] = self.generate_order_sn()
return attrs
class Meta:
model = OrderInfo
fields = "__all__"
（2）trade/views.py
class OrderViewset(mixins.ListModelMixin, mixins.RetrieveModelMixin, mixins.CreateModelMixin, mixins.DestroyModelMixin,
viewsets.GenericViewSet):
"""
订单管理
list:
获取个人订单
delete:
删除订单
create：
新增订单
"""
permission_classes = (IsAuthenticated, IsOwnerOrReadOnly)
authentication_classes = (JSONWebTokenAuthentication, SessionAuthentication)
serializer_class = OrderSerializer
#动态配置serializer
def get_serializer_class(self):
if self.action == "retrieve":
return OrderDetailSerializer
return OrderSerializer
#获取订单列表
def get_queryset(self):
return OrderInfo.objects.filter(user=self.request.user)
#在订单提交保存之前还需要多两步步骤，所以这里自定义perform_create方法
#1.将购物车中的商品保存到OrderGoods中
#2.清空购物车
def perform_create(self, serializer):
order = serializer.save()
# 获取购物车所有商品
shop_carts = ShoppingCart.objects.filter(user=self.request.user)
for shop_cart in shop_carts:
order_goods = OrderGoods()
order_goods.goods = shop_cart.goods
order_goods.goods_num = shop_cart.nums
order_goods.order = order
order_goods.save()
#清空购物车
shop_cart.delete()
return order
（3）配置url
# 配置订单的url
router.register(r'orders', OrderViewset, base_name="orders")
