'Overrides the default to enable redirecting to the directory view after
deletion of a folder.
we need to fetch the object and find out who the parent is
before super, because super will delete the object and make it
impossible to find out the parent folder to redirect to.
The delete_view breaks with polymorphic models if the cascade will
try delete objects that are of different polymorphic types
(AttributeError: \'File\' object has no attribute \'file_ptr\').
The default implementation of the delete_view is hard to override
without just copying the whole big thing. Since we\'ve already done
the overriding work on the delete_files_or_folders admin action, we
can re-use that here instead.'

def delete_view(self, request, object_id, extra_context=None):

    try:
        obj = self.get_queryset(request).get(pk=unquote(object_id))
        parent_folder = obj.parent
    except self.model.DoesNotExist:
        parent_folder = None
    if request.POST:
        self.delete_files_or_folders(request, files_queryset=File.objects.none(), folders_queryset=Folder.objects.filter(id=object_id))
        if parent_folder:
            url = reverse(u'admin:filer-directory_listing', kwargs={u'folder_id': parent_folder.id})
        else:
            url = reverse(u'admin:filer-directory_listing-root')
        url = u'{0}{1}'.format(url, admin_url_params_encoded(request))
        return HttpResponseRedirect(url)
    return self.delete_files_or_folders(request, files_queryset=File.objects.none(), folders_queryset=Folder.objects.filter(id=object_id))
