slugify model on save

gistfile1.py

from django.template.defaultfilters import slugify as django_slugify


class MyModel(models.Model):

    def save(*args, **kwargs):
        # Build our slug from the name, keeping it short for
        # linkability, but still guarantee uniqueness
        if not self.pk and self.slug:
            self.slug = self.slugify(self.slug)
            i = 0
            while True:
                i += 1
                try:
                    sid = transaction.savepoint()
                    result = super(MyModel, self).save(*args, **kwargs)
                    transaction.savepoint_commit(sid)
                    return result
                except IntegrityError:
                    transaction.savepoint_rollback(sid)
                    self.slug = self.slugify(self.slug, i)

            super(MyModel, self).save(*args, **kwargs)

    def slugify(self, name_part, i=None):
        slug = django_slugify(name_part)
        if i is not None:
            slug += "-%d" % i
        return slug