Accessing Primary Key from URL in Django View Class

Question

I have a URL pattern mapped to a custom view class in my Django App, like so:

url( r'^run/(?P<pk>\d+)/$', views.PerfRunView.as_view( ))

The problem is, I cannot figure out how I can access 'pk' from the URL pattern string in my view class so that I can retrieve a specific model object based on its database id. I have googled, looked through the Django documentation, searched Stack Overflow, and I can't find a satisfactory answer at all.

Can anybody tell me?

Seafarer

#6427504 does this help ? – Yardmaster

docs.djangoproject.com/en/1.4/topics/class-based-views/… read the second note. – Elevenses

@Ankur Gupta Thanks for the links, but I'm still not totally clear on it. Is it part of self.kwargs? I thought I was getting the hang of Django, until I got into class-based views. I just don't understand them at all. – Seafarer

@luke class based view is just an abstraction I for one finds it annoying and stick to functions. I don't think they help a lot. Not necessary you need to use it. Using simple function against URLs work fine too. – Yardmaster

Answer 1

In a class-based view, all of the elements from the URL are placed into self.args (if they're non-named groups) or self.kwargs (for named groups). So, for your view, you can use self.kwargs['pk'].

Legibility

I've sorted it now. I even have a better understanding of how Django View classes work, too. Thanks! – Seafarer

Answer 2

to access the primary key in views post =

Class_name.objects.get(pk=self.kwargs.get('pk'))

Orrin

Answer 3

This is an example based on django restframework to retrieve an object using pk in url:

views.py

class ContactListView(generics.ListAPIView):
    queryset = Profile.objects.all()
    serializer_class = UserContactListSerializer

    def get(self, request, pk, *args, **kwargs):
        contacts = Profile.objects.get(pk=pk)
        serializer = UserContactListSerializer(contacts)
        return Response(serializer.data)

urls.py

    url(r'^contact_list/(?P<pk>\d+)/$', ContactListView.as_view())

Odds

Answer 4

As many have said self.kwargs works fine. It particularly helps in self.get_queryset() function, unlike list, create where pk works better.

Flout