Question

I have the following hierarchy of classes:

class ProfileUpdateView( UpdateView, LoggerMixin ):

    def get_context_data(self, **kwargs):
        context = super(ProfileCreateView, self).get_context_data(**kwargs)
        ...
        return context

UpdateView is in fact django.views.generic.UpdateView

class EventViewMixin(object):
    template_name = ...
    model = Event
    form_class = ...

    def get_success_url(self):
        return self.success_url + str(self.object.id)

Class UpdateEventView mixes ProfileUpdateView and EventViewMixin

class UpdateEventView(ProfileUpdateView, EventViewMixin):

    def form_valid(self, form):
        ...
        return super(UpdateEventView, self).form_valid(form)

The problem in that for some reason the field “model=Event” is not visible to the framework when
it tries to use UpdateEventView. So I get the error:

UpdateEventView is missing a queryset. Define UpdateEventView.model, UpdateEventView.queryset, or override UpdateEventView.get_object().

What am I missing?

DISCLAIMER: I’m sort of a newbie to Python/Django.

Answer 1

So my question in sort of dumb …
The problem is in the order of the mixins:

class UpdateEventView(ProfileUpdateView, EventViewMixin):
    ....

must be replaced with:

class UpdateEventView( EventViewMixin, ProfileUpdateView ):

This is because ProfileUpdateView has in its inheritance tree a field “model=None”,
and if ProfileUpdateView is on the first position in the that is the value that
will be considered. If EventViewMixin comes first, then the correct value is taken.