Django 1.11 and AttributeError: Can only be accessed via an instance when creating a new Topic

[smclenithan]

It would seem that after upgrading to Django 1.11 I am getting this error at this point:

django-machina/machina/models/fields.py

Line 113 in f8e816e

raise AttributeError(_('Can only be accessed via an instance.'))

[07/Jun/2017 14:16:29] ERROR [django.request:135] Internal Server Error: /forum/forum/test-forum-77/topic/create/
Traceback (most recent call last):
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/core/handlers/exception.py", line 41, in inner
    response = get_response(request)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/core/handlers/base.py", line 249, in _legacy_get_response
    response = self._get_response(request)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/core/handlers/base.py", line 187, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/core/handlers/base.py", line 185, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/contextlib.py", line 53, in inner
    return func(*args, **kwds)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/contextlib.py", line 53, in inner
    return func(*args, **kwds)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/contextlib.py", line 53, in inner
    return func(*args, **kwds)
  [Previous line repeated 1 more times]
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/views/generic/base.py", line 68, in view
    return self.dispatch(request, *args, **kwargs)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/apps/forum_permission/viewmixins.py", line 108, in dispatch
    return super(PermissionRequiredMixin, self).dispatch(request, *args, **kwargs)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/views/generic/base.py", line 88, in dispatch
    return handler(request, *args, **kwargs)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/apps/forum_conversation/views.py", line 548, in post
    return super(TopicCreateView, self).post(request, *args, **kwargs)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/apps/forum_conversation/views.py", line 434, in post
    poll_options_validated=poll_options_validated)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/apps/forum_conversation/views.py", line 494, in form_valid
    post_form, attachment_formset, poll_option_formset=poll_option_formset, **kwargs)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/apps/forum_conversation/views.py", line 348, in form_valid
    self.forum_post = post_form.save()
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/apps/forum_conversation/forms.py", line 204, in save
    return super(TopicForm, self).save(commit)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/apps/forum_conversation/forms.py", line 108, in save
    post.save()
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/apps/forum_conversation/abstract_models.py", line 304, in save
    super(AbstractPost, self).save(*args, **kwargs)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/db/models/base.py", line 806, in save
    force_update=force_update, update_fields=update_fields)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/db/models/base.py", line 831, in save_base
    update_fields=update_fields,
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/dispatch/dispatcher.py", line 193, in send
    for receiver in self._live_receivers(sender)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/dispatch/dispatcher.py", line 193, in <listcomp>
    for receiver in self._live_receivers(sender)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/apps/forum_member/receivers.py", line 31, in increase_posts_count
    profile, dummy = ForumProfile.objects.get_or_create(user=instance.poster)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/db/models/query.py", line 459, in get_or_create
    lookup, params = self._extract_model_params(defaults, **kwargs)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/db/models/query.py", line 521, in _extract_model_params
    property_names = self.model._meta._property_names
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/db/models/options.py", line 887, in _property_names
    dir(self.model) if isinstance(getattr(self.model, attr), property)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/django/db/models/options.py", line 887, in <setcomp>
    dir(self.model) if isinstance(getattr(self.model, attr), property)
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/site-packages/machina/models/fields.py", line 112, in __get__
    raise AttributeError(_('Can only be accessed via an instance.'))

[ellmetha]

@smclenithan the problem only affects Django 1.11.2 if I am correct. There is a PR fixing this (#66) that I'll review soon. A new version should be released after that 😉

[smclenithan]

Fantastic, Yes it seems I jumped directly to 1.11.2. I didn't even see that that PR.