Django出现NoReverseMatch错误：如何为模型生成详情页URL？

错误信息 #

NoReverseMatch at /earrings

Reverse for 'product-detail' with arguments '('', '')' not found. 1 pattern(s) tried: ['product/(?P[0-9]+)/(?P[-a-zA-Z0-9_]+)/\Z']

现有配置 #

模型代码 #

class Product(models.Model):
    name = models.CharField(max_length=400)
    price = models.IntegerField(default=0)
    description = RichTextField(null=True, blank=True)
    slug = models.SlugField(unique=True, null=True, blank=True, max_length=400)
    create_at = models.DateTimeField(null=True, blank=True)
    id = models.AutoField(primary_key=True)
    
    def get_absolute_url(self):
        return reverse('product-detail', kwargs={'pk': self.pk, 'slug': self.slug})
    
    def __str__(self):
        return f'{self.name}'

视图代码 #

class ProductDetailView(DetailView): # this is the product detailView
    model = Product
    template_name = 'tehApp/product_detail.html'
    context_object_name = 'products'
    
    def get_context_data(self, *args, **kwargs):
        context = super(Product, self).get_context_data(*args, **kwargs)
        context['Bar'] = Bar.objects.first()
        context['Products'] = Product.objects.all()
        return context
    
    def get_object(self):
        return get_object_or_404(Product, pk=self.kwargs['pk'])

URL配置 #

urlpatterns = [
    path('product/<int:pk>/<slug:slug>/', ProductDetailView.as_view(), name='product-detail'),
]

模板代码 #

{% for product in products %}
<div class="item" data-name="{{ product.name }}" data-price="{{ product.price }}" data-date="{{ product.create_at|date:"Y-m-d\TH:i:s" }}">
        <div class="relative">
            <div class="relative thumbnail">
                {% with images=product.images.all %}
                    {% if images|length > 0 %}
                        <a href="{% url 'product-detail' product.pk product.slug %}">
                            <img width="250px" height="250px" class="" src="{{ images.0.image.url }}" alt="">
                        </a>
                    {% endif %}
                    {% if images|length > 1 %}
                        <img width="100%" height="100%" class="hidden" src="{{ images.1.image.url }}" alt="">
                    {% endif %}
                {% endwith %}
                <a href="{% url 'product-detail' product.pk product.slug %}" class="absolute top-0 w-full h-full bg-transparent"></a>
                <div class="hidden quickaddtocart">Add to Cart</div>
            </div>
            <p class="caption"><a href="{% url 'product-detail' product.pk product.slug %}">{{ product.name }}</a></p>
            <div class="caption-price">${{ product.price }}</div>
        </div>
</div>
{% endfor %}

问题分析与解决方案 #

1. 修复视图父类调用错误 #

视图中get_context_data方法的super(Product, self)是错误调用，需替换为当前视图类，否则会导致上下文数据异常：

def get_context_data(self, *args, **kwargs):
    context = super(ProductDetailView, self).get_context_data(*args, **kwargs)
    context['Bar'] = Bar.objects.first()
    context['Products'] = Product.objects.all()
    return context

2. 确保Product对象slug非空 #

错误提示传递空参数，说明部分Product的slug字段未赋值。URL配置中<slug:slug>为必填参数，需保证每个产品都有有效slug：

• 方法一：重写模型save方法自动生成slug：

from django.utils.text import slugify

class Product(models.Model):
    # ... 其他字段 ...
    
    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.name)
            # 处理slug重复情况
            counter = 1
            while Product.objects.filter(slug=self.slug).exists():
                self.slug = f'{slugify(self.name)}-{counter}'
                counter += 1
        super().save(*args, **kwargs)

• 方法二：批量更新现有空slug的产品（在Django Shell执行）：

from django.utils.text import slugify
from yourapp.models import Product

for product in Product.objects.filter(slug__isnull=True):
    product.slug = slugify(product.name)
    product.save()

3. 优化URL生成逻辑 #

模板中可直接调用模型的get_absolute_url方法，减少重复代码并利用模型层逻辑：

<a href="{{ product.get_absolute_url }}">
    <img width="250px" height="250px" class="" src="{{ images.0.image.url }}" alt="">
</a>

内容的提问来源于stack exchange，提问作者box