我要创建shoppig购物车。我从“ Beginning Django E-Commerce”一书中使用了很多代码（作者：Jim McGaw）。
代码错误已得到修复，系统几乎已准备就绪，因此 可以用作购物车的完整项目。
但是，它仍然不完整，还有一些问题需要我继续讨论。
app_name = 'shop'
urlpatterns = [
path('product/', views.all_product, name='all_product'),
path('product/<slug:slug>/', views.single_product, name='single_product'),
path('cart/', views.show_cart, name='show_cart'),
]
def single_product(request, slug):
p = get_object_or_404(Product, slug=slug)
# need to evaluate the HTTP method
if request.method == 'POST':
# add to cart…create the bound form
postdata = request.POST.copy()
form = ProductAddToCartForm(request, postdata)
# check if posted data is valid
if form.is_valid():
# add to cart and redirect to cart page
add_to_cart(request)
print("************^^^^(((((((((((")
# if test cookie worked, get rid of it
if request.session.test_cookie_worked():
request.session.delete_test_cookie()
return redirect('show_cart')
else:
# it’s a GET, create the unbound form. Note request as a kwarg
form = ProductAddToCartForm(request=request)
# assign the hidden input the product slug
form.fields['product_slug'].widget.attrs['value'] = slug
# set the test cookie on our first GET request
request.session.set_test_cookie()
template = 'shop/client_shop/single_product.html'
context = {'product': p}
return render(request, template, context)
def show_cart(request):
if request.method == 'POST':
postdata = request.POST.copy()
if postdata['submit'] == 'Remove':
remove_from_cart(request)
if postdata['submit'] == 'Update':
update_cart(request)
cart_items = get_cart_items(request)
page_title = 'Shopping Cart'
cart_sub_total = cart_subtotal(request)
context = {'cart_items': cart_items, 'page_title': page_title, 'cart_sub_total': cart_sub_total}
template = "shop/cart/cart.html"
return render(request, template, context)
from .models import CartItem, Product
from django.shortcuts import get_object_or_404
import decimal
import random
CART_ID_SESSION_KEY = 'cart_id'
# Create random str with 50 length for each cart_id
def _generate_cart_id():
cart_id = ''
characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890!@#$%^&*()'
cart_id_length = 50
for y in range(cart_id_length):
cart_id += characters[random.randint(0, len(characters) - 1)]
return cart_id
# get the current user's cart id, sets new one if blank
def _cart_id(request):
if request.session.get(CART_ID_SESSION_KEY, '') == '':
request.session[CART_ID_SESSION_KEY] = _generate_cart_id()
return request.session[CART_ID_SESSION_KEY]
# return all items from the current user's cart
def get_cart_items(request):
return CartItem.objects.filter(cart_id=_cart_id(request))
# add an item to the cart
def add_to_cart(request):
postdata = request.POST.copy()
# get product slug from post data, return blank if empty
product_slug = postdata.get('product_slug', '')
# get quantity added, return 1 if empty
quantity = postdata.get('quantity', 1)
# fetch the product or return a missing page error
p = get_object_or_404(Product, slug=product_slug)
# get products in cart
cart_products = get_cart_items(request)
product_in_cart = False
# check to see if item is already in cart
for cart_item in cart_products:
if cart_item.product.id == p.id:
# update the quantity if found
cart_item.augment_quantity(quantity)
product_in_cart = True
if not product_in_cart:
# create and save a new cart item
ci = CartItem()
ci.product = p
ci.quantity = quantity
ci.cart_id = _cart_id(request)
ci.save()
# returns the total number of items in the user's cart
def cart_distinct_item_count(request):
return get_cart_items(request).count()
def get_single_item(request, item_id):
return get_object_or_404(CartItem, id=item_id, cart_id=_cart_id(request))
# update quantity for single item
def update_cart(request):
postdata = request.POST.copy()
item_id = postdata['item_id']
quantity = postdata['quantity']
cart_item = get_single_item(request, item_id)
if cart_item:
if int(quantity) > 0:
cart_item.quantity = int(quantity)
cart_item.save()
else:
remove_from_cart(request)
# remove a single item from cart
def remove_from_cart(request):
postdata = request.POST.copy()
item_id = postdata['item_id']
cart_item = get_single_item(request, item_id)
if cart_item:
cart_item.delete()
# gets the total cost for the current cart
def cart_subtotal(request):
cart_total = decimal.Decimal('0.00')
cart_products = get_cart_items(request)
for cart_item in cart_products:
cart_total += (cart_item.product.price * cart_item.quantity)
return cart_total
class Product(models.Model):
STATUE_CHOICE = (
('draft', 'draft'),
('future', 'future'),
('trash', 'trash'),
('publish', 'publish'),
)
author = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)
category = models.ForeignKey(ProductCategory, null=True, blank=True, on_delete=models.SET_NULL)
name = models.TextField(max_length=100, blank=True)
slug = models.SlugField(null=True, blank=True, unique=True)
publish_time = models.DateTimeField(null=True, auto_now_add=True)
price = models.PositiveIntegerField()
weight = models.PositiveIntegerField()
short_description = models.TextField(max_length=250, blank=True)
exist_amount = models.PositiveIntegerField(null=True, blank=True)
is_live = models.BooleanField(default=False)
statue = models.CharField(max_length=10, choices=STATUE_CHOICE, default=STATUE_CHOICE[3][0])
class ProductAddToCartForm(forms.Form):
quantity = forms.IntegerField(
widget=forms.TextInput(attrs={'size': '2', 'value': '1', 'class': 'quantity', 'maxlength': '5'}),
error_messages={'invalid': 'Please enter a valid quantity.'}, min_value=1)
product_slug = forms.CharField(widget=forms.HiddenInput())
# override the default __init__ so we can set the request
def __init__(self, request=None, *args, **kwargs):
self.request = request
super(ProductAddToCartForm, self).__init__(*args, **kwargs)
# custom validation to check for cookies
def clean(self):
if self.request:
if not self.request.session.test_cookie_worked():
raise forms.ValidationError("Active your cookies!")
return self.cleaned_data
<!DOCTYPE html>
{% extends "base/website_header.html" %}
{% block body_block %}
{% block content %}
<a href="{% url 'shop:single_product' product.slug %}">{{ product.name }}</a>
<br>
Category: <a href=#>{{ product.category }}</a>
<br>
<form method="post" action="" class="cart">
{% csrf_token %}
{{ form.as_p }}
<br/>
<label for=”quantity”>Quantity</label><input type="text" id="quantity" value="1" />
<input type="submit" value="Add To Cart" name="submit" alt="Add To Cart"/>
</form>
<div class="cb"></div>
<br>
Description: {{ product.short_description }}
{% endblock %}
{% endblock %}
<!DOCTYPE html>
{% extends "base/website_header.html" %}
{% block body_block %
<table summary="Your Shopping Cart" id="shopping_cart">
<caption>Your Shopping Cart</caption>
<thead>
<tr>
<th scope="col">Product</th>
<th scope="col">Price</th>
<th></th>
<th></th>
<th></th>
<th scope="col" class="right">Total</th>
</tr>
</thead>
<tfoot>
<tr>
<th class="right" colspan="5">
</th>
<th class="right">
{{ cart_sub_total }}
</th>
</tr>
{% if cart_items %}
<tr>
<th class="right" colspan="6">
<a href="#">Checkout Now</a>
</th>
</tr>
{% endif %}
</tfoot>
<tbody>
{% if cart_items %}
{% for item in cart_items %}
<tr>
<td>
<a href="{{ item.get_absolute_url }}" class="cart">
{{ item.name }}
</a>
</td>
<td>{{ item.price }}</td>
<td class="right">
<form method="post" action="" class="cart">
<label for="quantity">Quantity:</label>
<input type="text" name="quantity" value="{{ item.quantity }}" id="quantity"
size="2" class="quantity" maxlength="5"/>
<input type="hidden" name="item_id" value="{{ item.id }}"/>
<input type="submit" name="submit" value="Update"/>
</td>
<td>
<form method="post" action="." class="cart">
<input type="hidden" name="item_id" value="{{ item.id }}"/>
<input type="submit" name="submit" value="Remove"/>
</form>
</td>
<td class="right">{{ item.total }}</td>
</tr>
{% endfor %}
{% else %}
<tr>
<td colspan="6" style="height:30px;">
Your cart is empty.
</td>
</tr>
{% endif %}
</tbody>
</table>
{% endblock %}
我可以看到单个产品页面，但是我有这个问题：
- 我无法将产品添加到购物车。
- 我看不到购物车页面并且它不起作用。