Question

编辑：

我的目标是创建一个小型电子商务。在我的索引中，我有一个产品列表，其中一个属性是一个名为in_cart的布尔值，它声明产品是否在购物车中。默认情况下，所有布尔值均为false。在我的模板中是一个表格，其中包含所有产品，我旁边放置了一个按钮“添加到购物车”，该按钮重定向到购物车模板。但是，当我单击添加到购物车时，所讨论的布尔值不会更改为true。有什么想法吗？

    <table>
    <tr>
        <th>List of car parts available:</th>
    </tr>
    <tr>
        <th>Name</th>
        <th>Price</th>
    </tr>
    {% for product in products_list %}
    <tr>
      <td>{{ product.id }}</td>
      <td>{{ product.name }}</td>
      <td>${{ product.price }}</td>
      <td>{% if not product.in_cart %}
              <form action="{% url 'add_to_cart' product_id=product.id %}" method="POST">
                {% csrf_token %}
                <input type="submit" id="{{ button_id }}" value="Add to cart">
              </form>
          {% else %}
              {{ print }}
          {% endif %}
      </td>
    </tr>
    {% endfor %}
  </table>

  <a href="{% url 'cart' %}">See cart</a>

这些是我的观点：

def index(request):
    if request.method == "GET":
        products_list = Product.objects.all()
        template = loader.get_template('products/index.html')
        context = {'products_list': products_list}
        return HttpResponse(template.render(context, request))
    return HttpResponse('Method not allowed', status=405)


def cart(request):
    cart_list = Product.objects.filter(in_cart = True)
    template_cart = loader.get_template('cart/cart.html')
    context = {'cart_list': cart_list}
    return HttpResponse(template_cart.render(context, request))


def add_to_cart(request, product_id):
    if request.method == 'POST':
        try:
            product = Product.objects.get(pk=product_id)
            product.in_cart = True
            product.save()
        except Product.DoesNotExist:
            return HttpResponse('Product not found', status=404)
        except Exception:
            return HttpResponse('Internal Error', status=500)
    return HttpResponse('Method not allowed', status=405)

型号：

class Product(models.Model):
    name = models.CharField(max_length=200)
    price = models.IntegerField()
    in_cart = models.BooleanField(default=False)
    ordered = models.BooleanField(default=False)
    def __str__(self):
        return self.name

URLs

urlpatterns = [
    path('', views.index, name='index'),
    path('cart/', views.cart, name='cart')
    re_path(r'^add_to_cart/(?P<product_id>[0-9]+)$', views.add_to_cart, name='add_to_cart')
]

我的终端错误

File "/Users/Nicolas/code/nicobarakat/labelachallenge/products/urls.py", line 8
    re_path(r'^add_to_cart/(?P<product_id>[0-9]+)$', views.add_to_cart, name='add_to_cart')
          ^
SyntaxError: invalid syntax

这是在localhost中的样子：

Answer 1

首先，您的if语句无法访问。因为您之前有一个return。当您在函数中调用return时，return之后的下一行函数将不会执行。

因此，您应该更改index函数。另外，您还应在发帖请求中发送产品的标识符。标识符可以是模型中的ID或任何其他唯一字段。

所以您的代码应该是这样的：

def index(request):
    if request.method == 'POST': # Request is post and you want to update a product.
        try:
            product = Product.objects.get(unique_field=request.POST.get("identifier")) # You should chnage `unique_field` with your unique filed name in the model and change `identifier` with the product identifier name in your form.
            product.in_cart = True
            product.save()
            return HttpResponse('', status=200)
        except Product.DoesNotExist: # There is no product with that identifier in your database. So a 404 response should return.
            return HttpResponse('Product not found', status=404)
        except Exception: # Other exceptions happened while you trying saving your model. you can add mor specific exception handeling codes here.
            return HttpResponse('Internal Error', status=500)
    elif request.method == "GET": # Request is get and you want to render template.
        products_list = Product.objects.all()
        template = loader.get_template('products/index.html')
        context = {'products_list': products_list}
        return HttpResponse(template.render(context, request))
    return HttpResponse('Method not allowed', status=405) # Request is not POST or GET, So we should not allow it.

我在代码注释中添加了您需要的所有信息。我认为您应该在python和django文件上花费更多时间。但是，如果您还有任何问题，可以在评论中提问。 问题后修改 如果您不想在表单中使用只读字段，则应在代码中进行两项更改。首先，应在product_id文件中添加带有urls.py参数的URL。像这样：

url(r'^add_to_cart/(?P<product_id>[0-9]+)$', 'add_to_cart_view', name='add_to_cart')

然后，您应该添加您的add_to_cart视图和index视图。您的观点应该是这样的：

def index(request): 
    if request.method == "GET":
        products_list = Product.objects.all()
        template = loader.get_template('products/index.html')
        context = {'products_list': products_list}
        return HttpResponse(template.render(context, request))
    return HttpResponse('Method not allowed', status=405)


def cart(request):
    cart_list = Product.objects.filter(in_cart = True)
    template_cart = loader.get_template('cart/cart.html')
    context = {'cart_list': cart_list}
    return HttpResponse(template_cart.render(context, request))


def add_to_cart(request, product_id):
    if request.method == 'POST':
        try:
            product = Product.objects.get(pk=product_id)
            product.in_cart = True
            product.save()
            return HttpResponse('', status=200)
        except Product.DoesNotExist:
            return HttpResponse('Product not found', status=404)
        except Exception:
            return HttpResponse('Internal Error', status=500)
    return HttpResponse('Method not allowed', status=405)

现在，您应该将表单的操作链接更改为此：

{% url 'add_to_cart' product_id=product.id %}

如何使用POST请求Django更改布尔值

1 个答案: