Fixture loading is interfered by signal handlers

[Jani Tiainen]

If profiles are setup as documented using unique foreignkeyand post_save signal it's impossible to import both as a fixture since creating user data creates (empty) profile that conflicts with fixtures to be loaded.

Specially it's inconvenient in testing. There should be option to disable or run signals deferred while loading fixture data.

[Russell Keith-Magee]

There is already a hook to check for this - data saved during a fixture load is loaded 'raw', and the 'raw' argument is passed to the pre/post save handlers. If you modify your pre/post save handlers to do nothing in the case of a raw save, you should be able to load fixtures without the problems you describe.

There might be an argument to be made that raw saves should disable signals completely - after all, the purpose of raw save is to prevent any clever 'on save' logic from being executed, and excluding signals from that process would make some sense. However, this could also be considered a backwards incompatibility. Marking DDN until we make that decision. Feel free to raise this on django-dev if you want to promote the idea.

[thcourbon@…]

I allow myself to bump this issue. I just came across this behavior. As far I'm concerned the current way to deal with fixture loading and signal handling by passing the 'raw' parameter is fine but it need documentation since their is nothing on that in ​http://docs.djangoproject.com/en/1.2/topics/signals/ or in ​http://docs.djangoproject.com/en/1.2/ref/django-admin/#loaddata-fixture-fixture.

If needed I would be pleased to contribute and write the required documentation in the right place.

[Klaas van Schelven]

This appears to be closely related to #8399

[Aymeric Augustin]

Replying to thcourbon@…:

As far I'm concerned the current way to deal with fixture loading and signal handling by passing the 'raw' parameter is fine but it need documentation since their is nothing on that in ​http://docs.djangoproject.com/en/1.2/topics/signals/ or in ​http://docs.djangoproject.com/en/1.2/ref/django-admin/#loaddata-fixture-fixture.

The "raw" parameter was added in Django 1.3. That's why it isn't visible in the documentation for Django 1.2.

​https://docs.djangoproject.com/en/dev/ref/signals/#django.db.models.signals.post_save

Russell provided a solution for this particular case, and #8399 tracks the more general question of disabling signals during fixtures loading.