如何实施Nodejs购物车系统

如何解决如何实施Nodejs购物车系统

您好，所以我正在学习NodeJS，Expressjs，因此我试图构建一个功能全面的购物车系统，即添加到购物车，从购物车中删除和删除。

所以我想将购物车保存到MongoDB，所以这是第一次处理架构中的数组，我无法完全理解文档中的内容

当前我所要做的是我可以为新用户成功添加购物车商品，因此，如果该用户更改了数量等，我尝试实现商品的更新，所以我已经成功完成了此工作，但现在我不明白如何更新购物车

我在这里显示我已成功替换了内容，但现在失败的是更新购物车数据库中的内容

[{"productID":"3","productName":"Hat","Qty":"1"}]  <<-- This was the initial state
[{"productID":"3","Qty":"6"}]  <<-- After user changes Qty

贝娄代码是我的尝试

const router = require("express").Router();
const Formidable = require("formidable");
const auth = require("../../MiddleWare/Auth");
const jwt = require("jsonwebtoken");
const { Users } = require("../../Models/User/User");
const Cart = require("../../Models/Cart/Cart");

router.post("/add-to-cart",async (request,response) => {
  const form = new Formidable.IncomingForm();
  const token = request.header("x-auth-token");
  
  //Here I try to make that I only add in cartItems of users that are logged by validating their tokens
  try {
    if (!token) {
      return response
        .status(401)
        .json({ message: "Token UnAuthorized cannot add to cart" });
    }
    const verifiedToken = jwt.verify(token,process.env.JWT_SECRET);

    if (!verifiedToken) {
      return response
        .status(401)
        .json({ message: "Token UnAuthorized cannot add to cart" });
    }

    const user = await Users.findOne({ _id: verifiedToken.id });
    const userEmail = user.email;
    form.parse(request,async (error,fields,files) => {
      const productID = fields.productID;
      const Qty = fields.Qty;
      const productName = fields.productName;

      const existingCartOwner = await Cart.findOne({ user: userEmail });
      
      //Here I try to check if the is a an email that has a cart(I use that because I made email to be unique when users register)
      if (!existingCartOwner) {
        const newCart = new Cart({
          user: userEmail,cart: {
            productID,productName,Qty,},});
        const savedCart = await newCart.save();
        return response.status(200).json(savedCart);
      }
      console.log(existingCartOwner.cart);
      const duplicateProduct = existingCartOwner.cart.map(
        (item) => item.productID === productID
      );
       
      if (duplicateProduct[0]) {
        const container = {
          productID,};
        const updatedCart = existingCartOwner.cart.map((item) =>
          item.productID === productID ? container : item
        );
      }
    });
  } catch (error) {
    return response.status(500).json({ error: error.message });
  }
});

module.exports = router;