CODEWITHSUNDEEP
djangodjango-modelsdjango-viewsdjango-class-based-views
alex
alex

Reputation: 2541

Object must be an instance or subtype of type in django

I'm learning django from thedjangobook and there is an example at class based views that it's in the django documentations aswell, here, my problem is that i'm getting an error when i'm trying to run this.

It is supposed to keep track of the last time anybody looked at an author:

models.py

class Author(models.Model):
    salutation = models.CharField(max_length=10, null=True)
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=40)
    email = models.EmailField(blank=True, verbose_name='e-mail')
    headshot = models.ImageField(upload_to='author_headshots', null=True, blank=True)
    last_accessed = models.DateTimeField(null=True)

urls.py

urlpatterns = [
    url(r'^authors/(?P<pk>[0-9]+)/$', views.AuthorDetailView.as_view(), name='AuthorDetailView'),
]

views.py

class AuthorDetailView(DetailView):

    def get_object(self, queryset=Author.objects.all()):
        # Call the superclass
        object_1 = super(Author, self).get_object()

        # Record the last accesed date
        object_1.last_accessed = timezone.now()
        object_1.save()

        # Return the object
        return object_1

Error:

Traceback (most recent call last):
  File "/home/alex/Documents/Proiecte/Django/Django_tutorial/venv/lib/python3.5/site-packages/django/core/handlers/exception.py", line 39, in inner
    response = get_response(request)
  File "/home/alex/Documents/Proiecte/Django/Django_tutorial/venv/lib/python3.5/site-packages/django/core/handlers/base.py", line 187, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/home/alex/Documents/Proiecte/Django/Django_tutorial/venv/lib/python3.5/site-packages/django/core/handlers/base.py", line 185, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/alex/Documents/Proiecte/Django/Django_tutorial/venv/lib/python3.5/site-packages/django/views/generic/base.py", line 68, in view
    return self.dispatch(request, *args, **kwargs)
  File "/home/alex/Documents/Proiecte/Django/Django_tutorial/venv/lib/python3.5/site-packages/django/views/generic/base.py", line 88, in dispatch
    return handler(request, *args, **kwargs)
  File "/home/alex/Documents/Proiecte/Django/Django_tutorial/venv/lib/python3.5/site-packages/django/views/generic/detail.py", line 115, in get
    self.object = self.get_object()
  File "/home/alex/Documents/Proiecte/Django/Django_tutorial/mysite/books/views.py", line 179, in get_object
    object_1 = super(Author, self).get_object()
TypeError: super(type, obj): obj must be an instance or subtype of type

Upvotes: 0

Views: 2770

Answers (1)

Sayse
Sayse

Reputation: 43300

Your get_object method is trying to call super, but you need to pass in the current class name rather than the model name

    object_1 = super(Author, self).get_object()

should be either

    object_1 = super(AuthorDetailView, self).get_object()
    object_1 = super().get_object()  # The args can be omitted for Python 3

Upvotes: 4

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