在线教育平台——购物车功能实现

依赖软件：Django\redis

测试工具：postman

redis中购物车数据存储结构

• redis最外层的key的实际意义是”luffy_shopping_car_userid_courseid”，也就是最后的两个数字分别代表的用户ID与需要加入购物车的课程ID
• 每个单独的课程中，包含课程名称，课程图片，课程价格策略，当前选中策略。

redis: {
    "luffy_shopping_car_1_1":
    {
        "title": "Linux基础",
        "img": "2.png",
        "policy": {
            "2": {
                "period": 60,
                "period_display": "2个月",
                "price": 1500
            }
        },
        "default_policy": "2"
    },
    "luffy_shopping_car_1_3": {
        ...
    }
}

实现思路

代码

在setting中设置redis配置：

CACHES = {
    "default": {
        "BACKEND": "django_redis.cache.RedisCache",
        "LOCATION": "redis://yourip:6379",
        "OPTIONS": {
            "CLIENT_CLASS": "django_redis.client.DefaultClient",
            "CONNECTION_POOL_KWARGS": {"max_connections": 100},
            "PASSWORD": "yourpassword",
        }
    }
}

路由设置urls.py:

url(r'^shopping_cart/$', shopping_cart.ShoppingCart.as_view()),

基于restframework的视图：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
@Author    : Young
@Email     : hyc554@outlook.com
@site      : http://www.cnblogs.com/huang-yc/
@File      : shopping_cart.py
@version   : 1.0
@Time      : 2018/11/4 20:51
Description about this file: 

"""
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.viewsets import GenericViewSet, ViewSetMixin
from django_redis import get_redis_connection
from utils.response_dict import BaseResponse
from api.views.auth import YcAuth
from api import models
from utils.error import PricePolicyInvalid
from django.core.exceptions import ObjectDoesNotExist
from django.conf import settings
import json


class ShoppingCart(APIView):
    authentication_classes = [YcAuth]
    conn = get_redis_connection('default')

    def post(self, request, *args, **kwargs):
        """
        向购物车中添加商品
        :param request:
        :param args:
        :param kwargs:
        :return:
        """
        ret = BaseResponse()
        try:
            # 在这里获得用户的课程ID与价格策略ID
            course_id = int(request.data.get('course_id'))
            policy_id = int(request.data.get('policy_id'))

            # 2. 获取专题课信息
            course = models.Course.objects.get(id=course_id)

            # 3.获取课程相关的所有价格策略
            price_policy_list = course.price_policy.all()
            price_policy_dict = {}
            for item in price_policy_list:
                price_policy_dict[item.id] = {
                    "period": item.valid_period,
                    "period_display": item.get_valid_period_display(),
                    "price": item.price
                }
            print(price_policy_dict)
            if policy_id not in price_policy_dict:
                raise PricePolicyInvalid('价格策略不合法')
            # 5. 将购物信息添加到redis中
            # self.conn
            # car_key = "luffy_shopping_car_%s_%s"
            car_key = settings.SHOPPING_CART_KEY % (request.auth.user_id, course_id,)
            car_dict = {
                'title': course.name,
                'img': course.course_img,
                'default_policy': policy_id,
                'policy': json.dumps(price_policy_dict)
            }
            # conn = get_redis_connection("default")
            self.conn.hmset(car_key, car_dict)
            ret.data = '添加成功'


        except PricePolicyInvalid as e:
            ret.data = 2001
            ret.error = e.msg
        except ObjectDoesNotExist as e:
            ret.data = 2002
            ret.error = '课程不存在'


        except Exception as e:
            ret.code = 1001
            ret.data = '获取购物车数据失败'
        return Response(ret.dict)

    def delete(self, request, *args, **kwargs):
        ret = BaseResponse()
        try:
            course_id_list = request.data.get('courseids')
            key_list = [settings.SHOPPING_CART_KEY % (request.auth.user_id, course_id,) for course_id in course_id_list]
            self.conn.delete(*key_list)
        except Exception as e:
            ret.code = 1002
            ret.error = "删除失败"

        return Response(ret.dict)

    def patch(self, request, *args, **kwargs):
        ret = BaseResponse()
        try:
            course_id = int(request.data.get('course_id'))
            policy_id = str(request.data.get('policy_id'))

            key = settings.SHOPPING_CART_KEY % (request.auth.user_id, course_id)

            if not self.conn.exists(key):
                ret.code = 1002
                ret.error = "购物车中不存在此课程"
                return Response(ret.dict)
            # 3. redis中获取所有的价格策略
            # 请注意这里对redis里的数据进行读取的操作
            policy_dict = json.loads(str(self.conn.hget(key, 'policy'), encoding='utf-8'))
            if policy_id not in policy_dict:
                ret.code = 1003
                ret.error = "价格策略不合法"
                return Response(ret.dict)

            self.conn.hset(key, 'default_policy', policy_id)
            ret.data = "修改成功"

        except Exception as e:
            ret.code = 2003
            ret.error = '修改数据失败'

        return Response(ret.dict)

    def get(self, request, *args, **kwargs):
        """
        查看购物车中所有的商品
        :param request:
        :param args:
        :param kwargs:
        :return:
        """
        ret = BaseResponse()
        try:
            key_match = settings.SHOPPING_CART_KEY % (request.auth.user_id, "*")

            course_list = []

            for key in self.conn.scan_iter(key_match, count=10):
                info = {
                    "title": self.conn.hget(key, 'title').decode('utf-8'),
                    "img": self.conn.hget(key, 'img').decode('utf-8'),
                    "policy": json.loads(self.conn.hget(key, 'policy').decode('utf-8')),
                    "default_policy": self.conn.hget(key, 'default_policy').decode('utf-8')
                }
                course_list.append(info)
            ret.data = course_list
        except Exception as e:
            ret.code = 1002
            ret.error = "获取失败"
        return Response(ret.dict)