How do I properly use a UUID id as a url parameter in Django?

Question

I’ve been trying to pass a UUID4 id into the url for a specific detail page.

After browsing Stackoverflow and other sites, here’s what I’ve tried so far:

Passing the url path as path('car/<uuid:id>/', views.CarDetailView.as_view(), name='car-detail'),

But this raises the error: Generic detail view CarDetailView must be called with either an object pk or a slug in the URLconf..

Since the uuid field is composed of both letters and numbers, I can’t use an int.

So I used this:

path(r"^(?P<car_model>w+)/$", views.CarDetailView.as_view(), name='car-detail'),

which returns the messy and broken url: showroom/%5E(%3FP09c32f72-5863-49fa-a42a-1d0fed274c4e%5Cw+)/$

Then I tried reverting to the original, but using a def_object method in the View class.

def get_object(self):
    object = get_object_or_404(CarInstance,title=self.kwargs['car_model'])
    return object

But this returns the error: “KeyError at /showroom/car/09c32f72-5863-49fa-a42a-1d0fed274c4e/
‘car_model'”

models.py

class CarInstance(models.Model):
    manufacturer = models.ForeignKey('Manufacturer', on_delete=models.SET_NULL, null=True)
    car_model = models.CharField('Model', max_length=50, null=True)

views.py

class CarDetailView(generic.DetailView):
    model = CarInstance
    template_name = 'car_detail'

    def get_queryset(self):
         return CarInstance.objects.all()

    def get_object(self):
           object = get_object_or_404(CarInstance,title=self.kwargs['car_model'])
           return object

    def get_absolute_url(self):
            return reverse('showroom:car-detail', args=[str(self.pk)])

The urls should be be formatted as showroom/car/09c32f72-5863-49fa-a42a-1d0fed274c4e/, which brings up the detail view for the specific object.

Any ideas?

Update

According to the answer below, I changed the get_object override to

    slug_field = 'title'
    slug_url_kwarg = 'car_detail'

But I’m still getting the same urlconf must be called with slug or int error. Should I define the slugh in the models?

Update 2

I’ve changed the urlconf, but it’s raising the same error. Here’s the full traceback

Environment:


Request Method: GET
Request URL: http://localhost:8000/showroom/car/09c32f72-5863-49fa-a42a-1d0fed274c4e/

Django Version: 2.2.5
Python Version: 3.7.4
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'showroom']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']



Traceback:

File "C:UsersUSEREnvstorquelibsite-packagesdjangocorehandlersexception.py" in inner
  34.             response = get_response(request)

File "C:UsersUSEREnvstorquelibsite-packagesdjangocorehandlersbase.py" in _get_response
  115.                 response = self.process_exception_by_middleware(e, request)

File "C:UsersUSEREnvstorquelibsite-packagesdjangocorehandlersbase.py" in _get_response
  113.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:UsersUSEREnvstorquelibsite-packagesdjangoviewsgenericbase.py" in view
  71.             return self.dispatch(request, *args, **kwargs)

File "C:UsersUSEREnvstorquelibsite-packagesdjangoviewsgenericbase.py" in dispatch
  97.         return handler(request, *args, **kwargs)

File "C:UsersUSEREnvstorquelibsite-packagesdjangoviewsgenericdetail.py" in get
  106.         self.object = self.get_object()

File "C:UsersUSEREnvstorquelibsite-packagesdjangoviewsgenericdetail.py" in get_object
  47.                 "pk or a slug in the URLconf." % self.__class__.__name__

Exception Type: AttributeError at /showroom/car/09c32f72-5863-49fa-a42a-1d0fed274c4e/
Exception Value: Generic detail view CarDetailView must be called with either an object pk or a slug in the URLconf.

** Another update **

Thanks to help from @ruddra, I changed the path to match the slug_url_kwarg = ‘car_detail’ It looks like this now:

path('car/<slug:car_detail>/', views.CarDetailView.as_view(), name='car-detail')

However, now the page raises a 404 error.

Page not found (404)
Request Method: GET
Request URL:    http://localhost:8000/showroom/car/09c32f72-5863-49fa-a42a-1d0fed274c4e/
Raised by:  showroom.views.CarDetailView
No car instance found matching the query

Asked By: Rene

||

Source

Answer 1

You don’t need to override get_object() method. You can simply use slug_url_kwarg and slug_field. Like this:

class CarDetailView(generic.DetailView):
    model = CarInstance
    template_name = 'car_detail'
    slug_field = 'title'
    slug_url_kwarg = 'car_model'

More information can be found in get_object() documentation.

Answered By: ruddra

Answer 2

Create get_absolute_url() in models.py:

def get_absolute_url(self):
    return reverse('car-detail', args=[str(self.<yourUUIDFieldName>)]) # self.car_model

Set URL in urls.py:

urlpatterns = [
    path('car/<uuid:yourUUIDFieldName>/', # 'car:<uuid:car_model'>
    views.CarDetailView.as_view(), name='car-detail'),
]

Try to change the views:

class CarDetailView(DetailView):
    model = CarInstance
    slug_field = '<uuid:yourUUIDFieldName>' # -> 'car_model'
    slug_url_kwarg = '<uuid:yourUUIDFieldName>' # -> 'car_model'
    template_name = 'car_detail.html'

In addition try this if you like:

import uuid
car_model = models.UUIDField(default=uuid.uuid4, unique=True)

Replace yourUUIDFieldName with car_model check if this works,
in my way, i have no idea, i’m just a beginner like others, hope u get something out of it

Answered By: wolfrevokcats

Answer 3

Although this is too late.However, someone could find it helpful.You can modify your modules as below:

Your models.py:

import uuid as uuid_lib
class CarInstance(models.Model):
    manufacturer = models.ForeignKey('Manufacturer', on_delete=models.SET_NULL, null=True)
    car_model = models.CharField('Model', max_length=50, null=True)
    uuid = models.UUIDField(
        db_index=True,
        default=uuid_lib.uuid4,
        editable=False, 
        unique=True,)

urls.py:

path('car/<uuid:uuid>/', views.CarDetailView.as_view(), name='car-detail'),

Lastly your views.py:

class CarDetailView(generic.DetailView):
    model = CarInstance
    template_name = 'car_detail'
    slug_field = 'uuid'
    slug_url_kwarg = 'uuid'

Answered By: pouya

How do I properly use a UUID id as a url parameter in Django?

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