[Django]-Is it okay to set instance variables in a Django class based view?

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59👍

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According to the source of django.views.generic.base.View.as_view:

  • on django startup, as_view() returns a function view, which is not called
  • on request, view() is called, it instantiates the class and calls dispatch()
  • the class instance is thread safe

According to the source of django.views.generic.base.View.__init__, the request object is out of scope at this point so you can’t parse it in your own constructor overload.

However, you could parse the request and set class view instance attributes in an overload of django.views.generic.base.View.dispatch, this is safe according to the source:

class YourView(SomeView):
    def dispatch(self, request, *args, **kwargs):
        # parse the request here ie.
        self.foo = request.GET.get('foo', False)

        # call the view
        return super(YourView, self).dispatch(request, *args, **kwargs)
👤jpic

2👍

@jpic provided a great answer. Inspired from it, I would like to reference the following blog post where the author claims that:

… We cannot override view, as doing so would require overriding
as_view(). Overriding dispatch() is appealing (and what I did
originally when I presented this talk) because it offers a single
simple place to do so, but this defies the logic of dispatch().
Instead, it is best to call set_account() in overrides of both get()
and post(). …

Therefore, one can override the get or post methods and set any self.whatever variables. It feels somehow cleaner.

👤raratiru

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