import django_filters


class FilterMixin(object):
    filterset_class:django_filters.FilterSet

    def get_filterset_class(self):
        return self.filterset_class

    def get_context_data(self, *, object_list=None, **kwargs):
        context_data = super().get_context_data(**kwargs)
        filter = self.get_filterset_class()(self.request.GET, queryset=self.get_queryset())
        context_data['filter'] = filter
        return context_data

    def get_queryset(self):
        qs = super().get_queryset()
        qs = self.get_filterset_class()(self.request.GET, queryset=qs).qs
        return qs