View queryset is not actually filtered

[seav]

A view that has both permission_filter_queryset and get_queryset() in the same class definition will fail to filter the queryset.

For example, if I have the following view class definition:

class DetailProjList(PermissionRequiredMixin, generic.ListView):
    permission_required = 'proj.list'
    permission_filter_queryset = ['proj.detail']

    def get_queryset(self):
        return Project.objects.all()

The list of projects displayed is not actually filtered. While PermissionRequiredMixin.has_permission() is able to construct self.filtered_queryset, this filtered queryset is not called by the view rendering process because DetailProjList's get_queryset() method masks BasePermissionRequiredMixin's get_queryset() method.

It seems filtered querysets only work if the desired get_queryset() is only inherited via a mixin or a parent class and not declared in the view class itself.

[ian-ross]

Let me think about this. I usually think of get_queryset as one of Django's DO WHAT I SAY methods, in the sense that, if you override it in a base view class, you are saying very clearly what you want the queryset to be, irrespective of whatever else is going on. I don't know if that's the right way to think of it.

What's the use case for this anyway? I don't think there are any instances of this in the current platform code.

[seav]

I encountered this during my current coding. I wanted to override the get_queryset of a mixin, which returns a list of resources attached to the project, to instead return all resources in a project (whether attached to the project or not) in one particular view. To avoid this bug, I ended up just modifying the mixin itself to behave differently based on a new view class attribute.

Of course I can't do that if the mixin is not my code, so a workaround is to create a wrapper parent class, but that sounds like a kludge.