Django 2.2.5 товар не отображается в корзине

Question

Я создаю сайт электронной коммерции, используя django 2.2.5.Я следовал учебному пособию по udemy , где инструктор движется быстрыми темпами, и он использует более старую версию django, которую я постоянно пытаюсь приостановить, чтобы убедиться, что мой код работает правильно (это УЖАСНО).Я сейчас создаю корзину для покупок.Цена обновляется правильно, но цена и описание товара (ов) не отображаются.Я проследил, проверил все видео, ведущие к этой части проекта, но я не могу найти, что я сделал неправильно, поэтому я решил приехать сюда для второго / третьего взгляда, который может бытьЯ могу понять, почему не отображается цена и описание товара (ов).

cart (cart.html): у меня есть forloop.counter, который просматривает товары и должен отображать цену и описаниетоваров, добавленных в корзину.

{% extends 'base.html' %}
{% block content %}
{% load staticfiles %}

<div class="pb-5">
    <div class="container">
      <div class="row">
        <div class="col-lg-12 p-5 bg-white rounded shadow-sm mb-5">

          <!-- Shopping cart table -->
          <div class="table-responsive">
               {% if cart.product.exists %}
            <table class="table">
              <thead>
                <tr>
                  <th scope="col" class="border-0 bg-light">
                    <div class="p-2 px-3 text-uppercase">Product</div>
                  </th>
                  <th scope="col" class="border-0 bg-light">
                    <div class="py-2 text-uppercase">Price</div>
                  </th>
                  <th scope="col" class="border-0 bg-light">
                    <div class="py-2 text-uppercase">Quantity</div>
                  </th>
                  <th scope="col" class="border-0 bg-light">
                    <div class="py-2 text-uppercase">Remove</div>
                  </th>
                </tr>
              </thead>
              <tbody>
              {% for product in cart.products.all %}
                <tr>
                  <th scope="row" class="border-0">{{ forloop.counter }}
                    <div class="p-2">
                      <img src="{{product.image}}" alt="" width="70" class="img-fluid rounded shadow-sm">
                      <div class="ml-3 d-inline-block align-middle">
                        <h5 class="mb-0"> <a href="{{ product.get_absolute_url }}" class="text-dark d-inline-block align-middle">{{ product.name }}</a></h5><span class="text-muted font-weight-normal font-italic d-block">Category: Watches</span>
                      </div>
                    </div>
                  </th>
                  <td class="border-0 align-middle"><strong>{{product.price}}</strong></td>
                  <td class="border-0 align-middle"><strong>3</strong></td>
                  <td class="border-0 align-middle"><a href="#" class="text-dark"><i class="fa fa-trash"></i></a></td>
                </tr>
              {% endfor %}
              </tbody>
            </table>
          </div>
            {% else %}
            <p class="lead">Cart is empty</p>
            {% endif %}
          <!-- End -->
        </div>
      </div>

      <div class="row py-5 p-4 bg-white rounded shadow-sm">
        <div class="col-lg-6">
          <div class="bg-light rounded-pill px-4 py-3 text-uppercase font-weight-bold">Coupon code</div>
          <div class="p-4">
            <p class="font-italic mb-4">If you have a coupon code, please enter it in the box below</p>
            <div class="input-group mb-4 border rounded-pill p-2">
              <input type="text" placeholder="Apply coupon" aria-describedby="button-addon3" class="form-control border-0">
              <div class="input-group-append border-0">
                <button id="button-addon3" type="button" class="btn btn-dark px-4 rounded-pill"><i class="fa fa-gift mr-2"></i>Apply coupon</button>
              </div>
            </div>
          </div>
          <div class="bg-light rounded-pill px-4 py-3 text-uppercase font-weight-bold">Instructions for seller</div>
          <div class="p-4">
            <p class="font-italic mb-4">If you have some information for the seller you can leave them in the box below</p>
            <textarea name="" cols="30" rows="2" class="form-control"></textarea>
          </div>
        </div>
        <div class="col-lg-6">
          <div class="bg-light rounded-pill px-4 py-3 text-uppercase font-weight-bold">Order summary </div>
          <div class="p-4">
            <p class="font-italic mb-4">Shipping and additional costs are calculated based on values you have entered.</p>
            <ul class="list-unstyled mb-4">
              <li class="d-flex justify-content-between py-3 border-bottom"><strong class="text-muted">Order Subtotal </strong><strong>{{ cart.subtotal }}</strong></li>
              <li class="d-flex justify-content-between py-3 border-bottom"><strong class="text-muted">Shipping and handling</strong><strong>$10.00</strong></li>
              <li class="d-flex justify-content-between py-3 border-bottom"><strong class="text-muted">Tax</strong><strong>$0.00</strong></li>
              <li class="d-flex justify-content-between py-3 border-bottom"><strong class="text-muted">Total</strong>
                <h5 class="font-weight-bold">{{ cart.total }}</h5>
              </li>
            </ul><a href="#" class="btn btn-dark rounded-pill py-2 btn-block">Procceed to checkout</a>
          </div>
        </div>
      </div>

    </div>
  </div>
</div>

{% endblock %}

корзина (cart / models.py):

from django.conf import settings
from django.db import models
from django.db.models.signals import pre_save, post_save, m2m_changed

from products.models import Product

User = settings.AUTH_USER_MODEL


class CartManager(models.Manager):
    def new_or_get(self, request):
        cart_id = request.session.get("cart_id", None)
        qs = self.get_queryset().filter(id=cart_id)
        if qs.count() == 1:
            new_obj = False
            cart_obj = qs.first()
            if request.user.is_authenticated and cart_obj.user is None:
                cart_obj.user = request.user
                cart_obj.save()
        else:
            cart_obj = Cart.objects.new(user=request.user)
            new_obj = True
            request.session['cart_id'] = cart_obj.id
        return cart_obj, new_obj

    def new(self, user=None):
        user_obj = None
        if user is not None:
            if user.is_authenticated:
                user_obj = user
        return self.model.objects.create(user=user_obj)


class Cart(models.Model):
    user = models.ForeignKey(User, null=True, blank=True, on_delete=True)
    products = models.ManyToManyField(Product, blank=True)
    subtotal = models.DecimalField(default=0.00, max_digits=19, decimal_places=2)
    total = models.DecimalField(default=0.00, max_digits=19, decimal_places=2)
    updated = models.DateTimeField(auto_now_add=True)
    timestamp = models.DateTimeField(auto_now_add=True)

    objects = CartManager()


def __str__(self):
    return str(self.id)


def m2m_changed_cart_receiver(sender, instance, action, *args, **kwargs):
    if action == 'post_add' or action == 'post_remove' or action == 'post_clear':
        products = instance.products.all()
        total = 0
        for x in products:
            total += x.price
        if instance.subtotal != total:
            instance.subtotal = total
            instance.save()


m2m_changed.connect(m2m_changed_cart_receiver, sender=Cart.products.through)


def pre_save_cart_receiver(sender, instance, *args, **kwargs):
    if instance.subtotal > 0:
        instance.total = instance.subtotal + 6
    else:
        instance.total = 0.00


pre_save.connect(pre_save_cart_receiver, sender=Cart)

(корзина / views.py):

from django.shortcuts import render, redirect

from products.models import Product
from .models import Cart


def cart_home(request):
    template = "carts/cart.html",
    cart_obj, new_obj = Cart.objects.new_or_get(request)
    return render(request, template, {"cart": cart_obj})


def cart_update(request):
    product_id = request.POST.get('product_id')
    if product_id is not None:
        product_obj = Product.objects.get(id=product_id)
        cart_obj, new_obj = Cart.objects.new_or_get(request)
        if product_obj in cart_obj.products.all():
            cart_obj.products.remove(product_obj)
        else:
            cart_obj.products.add(product_obj)
    return redirect("cart:home")

Просмотр продуктов (товаров / просмотров).py):

class ProductDetailSlugView(DetailView):
    queryset = Product.objects.all()
    template_name = "products/detail.html"

    def get_context_data(self, *args,  **kwargs):
        context = super(ProductDetailSlugView, self).get_context_data(*args, **kwargs)
        cart_obj, new_obj = Cart.objects.new_or_get(self.request)
        context['cart'] = cart_obj
        return context

    def get_object(self, *args, **kwargs):
        request = self.request
        slug = self.kwargs.get('slug')
        try:
            instance = Product.objects.get(slug=slug)
        except Product.DoesNotExist:
            raise Http404("Not Found")
        except Product.MultipleObjectsReturned:
            qs = Product.objects.filter(slug=slug)
            instance = qs.first()
        except:
            raise Http404("hmmm can't seem to find product")
        return instance

Answer 1

в cart.html Я изменил

{% if cart.product.exists%}

на

{% ifcart.products.exists%}