未登录用户无法将商品添加至购物车问题求助

大家好，我现在遇到一个棘手的问题：我想让未登录用户也能把商品加入购物车，但点击「加入购物车」按钮后，购物车完全没有任何变化。我已经写了后端视图、前端JS和页面模板，但未登录状态下的购物车逻辑完全不生效，求各位帮忙排查一下问题所在！

我的现有代码 #

1. views.py

from django.shortcuts import render
from django.http import JsonResponse
import json
import datetime
from .models import *

def store(request):
    if request.user.is_authenticated:
        customer = request.user.customer
        order, created = Order.objects.get_or_create(customer=customer, complete=False)
        items = order.orderitem_set.all()
        cartItems = order.get_cart_items
    else:
        # 临时模拟未登录用户的空购物车
        items = []
        order = {'get_cart_total':0, 'get_cart_items':0, 'shipping':False}
        cartItems = order['get_cart_items']

    products = Product.objects.all()
    context = {'products':products, 'cartItems':cartItems}
    return render(request, 'store/store.html', context)

def cart(request):
    if request.user.is_authenticated:
        customer = request.user.customer
        order, created = Order.objects.get_or_create(customer=customer, complete=False)
        items = order.orderitem_set.all()
        cartItems = order.get_cart_items
    else:
        # 临时模拟未登录用户的空购物车
        items = []
        order = {'get_cart_total':0, 'get_cart_items':0, 'shipping':False}
        cartItems = order['get_cart_items']

    context = {'items':items, 'order':order, 'cartItems':cartItems}
    return render(request, 'store/cart.html', context)

def checkout(request):
    if request.user.is_authenticated:
        customer = request.user.customer
        order, created = Order.objects.get_or_create(customer=customer, complete=False)
        items = order.orderitem_set.all()
        cartItems = order.get_cart_items
    else:
        # 临时模拟未登录用户的空购物车
        items = []
        order = {'get_cart_total':0, 'get_cart_items':0, 'shipping':False}
        cartItems = order['get_cart_items']

    context = {'items':items, 'order':order, 'cartItems':cartItems}
    return render(request, 'store/checkout.html', context)

def updateItem(request):
    data = json.loads(request.body)
    productId = data['productId']
    action = data['action']
    print('Action:', action)
    print('Product:', productId)

    customer = request.user.customer
    product = Product.objects.get(id=productId)
    order, created = Order.objects.get_or_create(customer=customer, complete=False)
    orderItem, created = OrderItem.objects.get_or_create(order=order, product=product)

    if action == 'add':
        orderItem.quantity = (orderItem.quantity + 1)
    elif action == 'remove':
        orderItem.quantity = (orderItem.quantity - 1)

    orderItem.save()

    if orderItem.quantity <= 0:
        orderItem.delete()

    return JsonResponse('Item was added', safe=False)

def processOrder(request):
    transaction_id = datetime.datetime.now().timestamp()
    data = json.loads(request.body)

    if request.user.is_authenticated:
        customer = request.user.customer
        order, created = Order.objects.get_or_create(customer=customer, complete=False)
        total = float(data['form']['total'])
        order.transaction_id = transaction_id

        if total == order.get_cart_total:
            order.complete = True
        order.save()

        if order.shipping == True:
            ShippingAddress.objects.create(
                customer=customer,
                order=order,
                address=data['shipping']['address'],
                city=data['shipping']['city'],
                state=data['shipping']['state'],
                zipcode=data['shipping']['zipcode'],
            )
    else:
        print('User is not logged in')

    return JsonResponse('Payment submitted..', safe=False)

2. cart.js

var UpdateBtns= document.getElementsByClassName('update-cart')

for(i=0;i< UpdateBtns.length;i++){
    UpdateBtns[i].addEventListener('click',function(){
        var productId = this.dataset.product
        var action = this.dataset.action
        console.log('productId',productId,'action',action)
        console.log('USER:',user)
        updateUserOrder(productId,action)
    })
}

function updateUserOrder(productId,action){
    var url = '/update_item/'
    fetch(url,{
        method : 'POST',
        headers : {
            'content-Type':'application/json',
            'X-CSRFToken':csrftoken,
        },
        body:JSON.stringify({'productId':productId,'action':action})
    })
    .then((Response)=>{
        return Response.json()
    })
    .then((data) =>{
        console.log('data:',data)
    })
}

3. checkout.html

{% extends 'shop_templates/main.html' %}
{% load static%}

{%block content %}
<div class="row">
    <div class="col-lg-6">
        <div class="box-element" id="form-wrapper">
            <form id="form">
                {% csrf_token %}
                <div id="user-info">
                    {% if not request.user.is_authenticated %}
                    <div class="form-field">
                        <input required class="form-control" type="text" name="name" placeholder="Name..">
                    </div>
                    <div class="form-field">
                        <input required class="form-control" type="email" name="email" placeholder="Email..">
                    </div>
                    {% endif %}
                </div>
                <div id="shipping-info">
                    <hr>
                    <p>shipping information :</p>
                    <div class="form-field">
                        <input class="form-control" type="text" name="address" placeholder="Address..">
                    </div>
                    <div class="form-field">
                        <input class="form-control" type="text" name="city" placeholder="City..">
                    </div>
                    <!-- 剩余代码未完成 -->
                </div>
            </form>
        </div>
    </div>
</div>
{% endblock content %}

我自己排查到的疑似问题 #

我发现updateItem视图完全没有处理未登录用户的逻辑！现在只有登录用户的订单关联逻辑，未登录用户的购物车只是用临时字典模拟的空数据，但点击添加按钮后，请求到update_item时会直接尝试获取request.user.customer，未登录状态下这一步肯定会报错，而且也没有用session来存储未登录用户的购物车数据。

但我不太清楚具体怎么修改才能让未登录用户的购物车正常工作，希望各位能给我一些具体的修改建议！

内容来源于stack exchange