Django NoReverseMatch Error: Generating URLs For Each Model

I’m facing a NoReverseMatch error in my Django application when trying to generate URLs for product detail pages. The error message indicates that the URL pattern for ‘product-detail’ with the provided pk and slug is not found. Here are the details of my setup:

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’]

Model:

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)
    FlavorText = models.CharField(null=True, blank=True, max_length=30)
    tags = models.ManyToManyField('Tag', related_name='products', blank=True)
    id = models.AutoField(primary_key=True)

    def save(self, *args, **kwargs):
        # Ensure slug is created from name
        if not self.slug:
            self.slug = slugify(self.name, allow_unicode=True)
        
        # Check if FlavorText is None and replace it with an empty string
        if self.FlavorText is None:
            self.FlavorText = ""

        super().save(*args, **kwargs)
    
    def get_absolute_url(self):
        return reverse('product-detail', kwargs={'pk': self.pk})
    
    def __str__(self):
        return f'{self.name} - {self.create_at}'
    
    class Meta:
        ordering = ['name', 'price', 'create_at']  # Default ordering

View:

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'])
    
class EarringsPageView(TemplateView): # this is the product list page
    model = Product
    template_name = 'tehApp/earrings.html'
    context_object_name = 'products'
    
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        earrings_tag = Tag.objects.get(name="Earrings")
        sort_order = self.request.GET.get('sort', 'newest')
        all_products = self.get_sorted_products(earrings_tag, sort_order)
        
        # Debugging output
        for product in all_products:
            print(f"Product ID: {product.pk}, Product Name: {product.name}")
        
        paginator = Paginator(all_products, 22)  # Initial load of 22 products
        page_number = self.request.GET.get('page', 1)
        page_obj = paginator.get_page(page_number)
        
        context['Bar'] = Bar.objects.first()    
        context['Products'] = page_obj
        context['all_products'] = all_products
        return context

    def get_sorted_products(self, earrings_tag, sort_order):
        if sort_order == 'pasc':
            return Product.objects.filter(tags=earrings_tag).order_by('price')
        elif sort_order == 'pdesc':
            return Product.objects.filter(tags=earrings_tag).order_by('-price')
        elif sort_order == 'newest':
            return Product.objects.filter(tags=earrings_tag).order_by('-create_at')
        else:
            return Product.objects.filter(tags=earrings_tag)  # Default sorting

URL:

urlpatterns = [
    path('earrings', EarringsPageView.as_view(), name='earrings'),
    path('load-more-products/', LoadMoreProductsView.as_view(), name='load_more_products'),
    path('<str:pk>/', ProductDetailView.as_view(), name='product-detail'),
]

Template:

{% 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="matchheight">
        <div class="relative">
            <div class="relative thumbnail">
                {% with images=product.images.all %}
                    {% if images|length > 0 %}
                        <a href="">
                            <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 %}" class="absolute top-0 w-full h-full bg-transparent"></a>
                <div class="hidden quickaddtocart">Add to Cart</div>
            </div>
            <div class="absolute top-0 w-full h-8">
                <div class="absolute top-3 left-3">
                    <i class="cursor-pointer fa-regular fa-heart wishlist-item" style="color: #3b3b3b;"
                    data-id="{{ product.id }}"></i>
                </div>
                <div class="itemtipbox">
                    <small class="itemtip">
                        {{ product.FlavorText }}
                    </small>
                </div>
            </div>
            <p class="caption"><a href="{% url 'product-detail' product.pk %}">{{ product.name }}</a></p>
            <div class="caption-price">${{ product.price }}</div>
        </div>
    </div>
</div>
{% endfor %}

Please raise further questions if necessary,
Any help or insights would be greatly appreciated!

What I tried:
I tried generating URLs for product detail pages in my Django application using the {% url ‘product-detail’ product.pk product.slug %} template tag. This should create a URL based on the pk (primary key) and slug of each Product instance.

What I expected:
I expected the URLs to be generated correctly and link to the detail pages of each product, where product.pk and product.slug would be substituted in the URL pattern.

What actually resulted:
Instead of generating valid URLs, I encountered a NoReverseMatch error with the message:

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’]

This error indicates that the URL pattern for product-detail could not be matched because it received empty values for pk and slug. The URL pattern expects non-empty pk and slug values.
Please help I’m totally stumped AA

Welcome @box !

What template are you showing here?

What view is rendering that template?

(For future reference, please specifically identify by name all files whose contents are being shown. Simply identifying it as a “template” provides no useful information.)

If it’s your ProductDetailView, then the issue is that with this line:

this is not valid:

because 'Products' != 'products'

However, I don’t believe that is the issue in this case, because you are iterating over a list, that it is getting from somewhere.

So we need to see the view that is rendering the given template.

1 Like

Heya Ken!
Thanks for the warm welcome, I really appreciate it.

You guessed it right. The View I’d been showing doesn’t belong to the template, it belongs to the detail page. I’m so sorry for the mix-up, This should be the View the template belongs to:

class EarringsPageView(TemplateView):
    model = Product
    template_name = 'tehApp/earrings.html'
    context_object_name = 'products'
    
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        earrings_tag = Tag.objects.get(name="Earrings")
        sort_order = self.request.GET.get('sort', 'newest')
        all_products = self.get_sorted_products(earrings_tag, sort_order)
        paginator = Paginator(all_products, 22)  # Initial load of 22 products
        page_number = self.request.GET.get('page', 1)
        page_obj = paginator.get_page(page_number)    
        context['Products'] = page_obj
        context['all_products'] = all_products
        return context

Oh also, thanks for the insight on the use of this forum!

Any help or insight would be really appreciated
Edit: You were right the template had a typo that wouldn’t render products directly, but I still can’t get the detail url’s of each product, thanks again

What is this get_sorted_products method? Where is it defined?

1 Like

Here’s the View in its entirety:

class ProductDetailView(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'])
    
class EarringsPageView(TemplateView):
    model = Product
    template_name = 'tehApp/earrings.html'
    context_object_name = 'products'
    
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        earrings_tag = Tag.objects.get(name="Earrings")
        sort_order = self.request.GET.get('sort', 'newest')
        all_products = self.get_sorted_products(earrings_tag, sort_order)
        paginator = Paginator(all_products, 22)  # Initial load of 22 products
        page_number = self.request.GET.get('page', 1)
        page_obj = paginator.get_page(page_number)
        context['Bar'] = Bar.objects.first()    
        context['Products'] = page_obj
        context['all_products'] = all_products
        return context
    
    def get_queryset(self):
        earrings_tag = Tag.objects.get(name="Earrings")
        sort_order = self.request.GET.get('sort', 'newest')
        products = self.get_sorted_products(earrings_tag, sort_order)
        for product in products:
            print(f"Product ID: {product.pk}, Product Name: {product.name}")
        return products

    def get_sorted_products(self, earrings_tag, sort_order):
        if sort_order == 'pasc':
            return Product.objects.filter(tags=earrings_tag).order_by('price')
        elif sort_order == 'pdesc':
            return Product.objects.filter(tags=earrings_tag).order_by('-price')
        elif sort_order == 'newest':
            return Product.objects.filter(tags=earrings_tag).order_by('-create_at')
        else:
            return Product.objects.filter(tags=earrings_tag)  # Default sorting

class LoadMoreProductsView(View):
    def get(self, request, *args, **kwargs):
        page_number = int(request.GET.get('page', 1))
        sort_order = request.GET.get('sort', 'newest')
        earrings_tag = Tag.objects.get(name="Earrings")
        all_products = self.get_sorted_products(earrings_tag, sort_order)

        initial_load_count = 22
        subsequent_load_count = 24

        if page_number == 1:
            offset = 0
            limit = initial_load_count
        else:
            offset = initial_load_count + subsequent_load_count * (page_number - 2)
            limit = subsequent_load_count

        print(f"Page number: {page_number}")
        print(f"Offset: {offset}, Limit: {limit}")

        remaining_products = all_products[offset:offset + limit]
        total_products_count = all_products.count()
        has_next = offset + limit < total_products_count

        print(f"Total products: {total_products_count}")
        print(f"Number of remaining products: {len(remaining_products)}")
        print(f"Has next: {has_next}")

        products_list = []
        for product in remaining_products:
            product_images = product.images.all()
            images = [{"image": image.image.url} for image in product_images]
            products_list.append({
                "name": product.name,
                "price": product.price,
                "create_at": product.create_at.isoformat(),
                "FlavorText": product.FlavorText,
                "id": product.id,
                "images": images
            })

        response = {
            "products": products_list,
            "has_next": has_next
        }
        return JsonResponse(response)

    def get_sorted_products(self, earrings_tag, sort_order):
        if sort_order == 'pasc':
            return Product.objects.filter(tags=earrings_tag).order_by('price')
        elif sort_order == 'pdesc':
            return Product.objects.filter(tags=earrings_tag).order_by('-price')
        elif sort_order == 'newest':
            return Product.objects.filter(tags=earrings_tag).order_by('-create_at')
        else:
            return Product.objects.filter(tags=earrings_tag)  # Default sorting

You’ve posted three different views here. Which view is executing when the error message is being generated? And is the template fragment shown above the template being rendered by that view?

1 Like

Oh, right. The EarringsPageView is the renderer for the template shown above. Sorry for the lack of clarification.

Do you see the output from this print statement in your server console?

1 Like

In django, TemplateView, the get_queryset method does not get called automatically. The get_queryset method is typically used in class-based views like ListView or DetailView, which are designed to work with querysets directly. TemplateView doesn’t use get_queryset since it’s more generic and doesn’t directly handle querysets.

But changing my code to this, I’m able to get them to print.

class EarringsPageView(TemplateView):
    model = Product
    template_name = 'tehApp/earrings.html'
    context_object_name = 'products'
    
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        earrings_tag = Tag.objects.get(name="Earrings")
        sort_order = self.request.GET.get('sort', 'newest')
        all_products = self.get_sorted_products(earrings_tag, sort_order)
        
        # Debugging output
        for product in all_products:
            print(f"Product ID: {product.pk}, Product Name: {product.name}")
        
        paginator = Paginator(all_products, 22)  # Initial load of 22 products
        page_number = self.request.GET.get('page', 1)
        page_obj = paginator.get_page(page_number)
        
        context['Bar'] = Bar.objects.first()    
        context['Products'] = page_obj
        context['all_products'] = all_products
        return context

    def get_sorted_products(self, earrings_tag, sort_order):
        if sort_order == 'pasc':
            return Product.objects.filter(tags=earrings_tag).order_by('price')
        elif sort_order == 'pdesc':
            return Product.objects.filter(tags=earrings_tag).order_by('-price')
        elif sort_order == 'newest':
            return Product.objects.filter(tags=earrings_tag).order_by('-create_at')
        else:
            return Product.objects.filter(tags=earrings_tag)  # Default sorting

Here’s the outpout

Product ID: 30, Product Name: Perfect Martini Lab Diamond Stud Earrings (3 ct. tw.)
Product ID: 29, Product Name: Perfect Martini Diamond Stud Earrings (2 ct. tw.)
Product ID: 16, Product Name: 2mm Huggie Perfect Hoop Earrings
Product ID: 28, Product Name: Arabella Cultured Pearl and Diamond Drop Earrings
Product ID: 27, Product Name: Coastal Ombre Tennis Earrings
Product ID: 26, Product Name: Soiree Sapphire Huggie Earrings
Product ID: 25, Product Name: Sunflower London Blue Topaz Earrings
Product ID: 24, Product Name: Florence Sapphire and Diamond Earrings (1/3 ct. tw.)
Product ID: 23, Product Name: Deux Diamond Hoop Earrings (1/2 ct. tw.)
Product ID: 22, Product Name: Knife Edge Hoop Earrings
Product ID: 21, Product Name: Juniper Diamond Gold Earrings
Product ID: 20, Product Name: Solitaire Amethyst Stud Earrings
Product ID: 19, Product Name: Foliage Bouquet Earrings
Product ID: 18, Product Name: Solitaire Opal Stud Earrings
Product ID: 17, Product Name: Zuri Huggie Earrings
Product ID: 15, Product Name: Petal Lab Emerald and Diamond Earrings
Product ID: 14, Product Name: Zuri Diamond Huggie Earrings
Product ID: 13, Product Name: Allegra Diamond Hoop Earrings
Product ID: 12, Product Name: Baroque Freshwater Cultured Pearl Earrings
Product ID: 11, Product Name: Solitaire Sapphire Stud Earrings
Product ID: 10, Product Name: Teardrop London Blue Topaz Earrings
Product ID: 9, Product Name: Baguette Diamond Cluster Hoop Earrings (1/4 ct. tw.)
Product ID: 8, Product Name: Juniper Diamond Earrings
Product ID: 5, Product Name: Round Diamond Stud Earrings (1 ct. tw.)
Product ID: 7, Product Name: Hydrangea Bouquet Earrings
Product ID: 6, Product Name: Luxe Diamond Huggie Earrings (1/2 ct. tw.)

Now I’m back to being confused.

The original error message you’ve posted shows that it’s trying to reverse a url containing two arguments. However, the url defined with the name product-detail only has one.

Do you have any other url defined with the name product-detail?

1 Like

Solved it, thanks.

It was because of me filling in the super with Product and self. It had to be empty

class ProductDetailView(DetailView):
    template_name = 'nasipWeb/product_detail.html'
    model = Product
    
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['Bar'] = Bar.objects.first()
        return context
    
    def get_object(self):
        return get_object_or_404(Product, pk=self.kwargs['pk'])

yeah it worked tysm