Pass parameter to django as_view function

Question

I have one url that passes a parameter through the as_view function:

url(
    r'^$',
    ChangeListView.as_view(
        columns=('username', 'email')
    ),
    name="user-list"
),

When i try to access the columns attribute in the view it returns None instead of the tuple that i have passed through the url

class ChangeListView(generic.ListView):
    columns = None

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        print(self.columns)
        # Returns None instead of tuple
        return context

Answer 1

You don't have anything that actually sets self.columns from the data you pass in.

But this isn't the right way to do it. Instead, pass it as an extra option, and access it from the kwargs.

url(
    r'^$',
    ChangeListView.as_view(),
    {'columns': ('username', 'email')}
    name="user-list"
),

...

print(self.kwargs['columns'])