Haystack tweaks for Django 1.7.7. I had to upgrade to Haystack 2.3.1 to get it to work with Django 1.7.7. I also had to update the Xapian backend. But I ran into problems. On my laptop anyway (Ubuntu 14.0.4), xapian gets mad when search terms are greater than 245 chars (or something) when indexing. So I created a custom field that would simply omit terms greater than 64 chars and used this field everywhere I previously used a CharField. Secondly, the custom search form was broken now. Something changed in the Xapian backend and exact searches stopped working. Fortunately the auto_query (which I was using originally and broke during an upgrade) started working again. So I cut the search form back over to doing an auto_query. I kept the form the same (3 fields) because I didn't want to change the form and I think it's better that way.

"""
Signal handlers for the potd application.

"""
from django.db.models.signals import post_save, post_delete

from potd.models import Photo, Sequence


def on_photo_save(sender, **kwargs):
    """
    This function is executed when a Photo is saved. It inserts the photo into
    the current sequence.

    """
    photo = kwargs['instance']
    Sequence.objects.insert_photo(photo.pk)


def on_photo_delete(sender, **kwargs):
    """
    This function is executed when a Photo is deleted. It removes the photo from
    the current sequence of photos.

    """
    photo = kwargs['instance']
    Sequence.objects.remove_photo(photo.pk)


post_save.connect(on_photo_save, sender=Photo, dispatch_uid='potd.receivers')
post_delete.connect(on_photo_delete, sender=Photo, dispatch_uid='potd.receivers')