def create_redirect(sender, instance, raw, **kwargs):
# Only proceed if not raw, we're dealing with an existing object, and the
# contrib redirects app is installed.
if not raw and instance.pk \
and 'django.contrib.redirects' in settings.INSTALLED_APPS:
from django.contrib.redirects.models import Redirect
# Only proceed if an existing object exists
try:
existing = sender.objects.get(pk=instance.pk)
except sender.DoesNotExist:
return
existing_path = existing.get_absolute_url()
new_path = instance.get_absolute_url()
if hasattr(instance, 'site') and existing.site != instance.site:
new_path = '//{0}{1}'.format(instance.site.domain, new_path)
if existing_path != new_path:
try:
redirect = Redirect.objects.get(site=existing.site,
old_path=existing_path)
except Redirect.DoesNotExist:
redirect = Redirect(site=existing.site, old_path=existing_path)
redirect.new_path = new_path
redirect.save()
