"""

Django Extensions abstract base model classes.

"""

from django.db import models

from django.utils.translation import ugettext_lazy as _

from django_extensions.db.fields import (ModificationDateTimeField,

                                         CreationDateTimeField, AutoSlugField)

class TimeStampedModel(models.Model):

    """ TimeStampedModel

    An abstract base class model that provides self-managed "created" and

    "modified" fields.

    """

    created = CreationDateTimeField(_('created'))

    modified = ModificationDateTimeField(_('modified'))

    class Meta:

        abstract = True

class TitleSlugDescriptionModel(models.Model):

    """ TitleSlugDescriptionModel

    An abstract base class model that provides title and description fields

    and a self-managed "slug" field that populates from the title.

    """

    title = models.CharField(_('title'), max_length=255)

    slug = AutoSlugField(_('slug'), populate_from='title')

    description = models.TextField(_('description'), blank=True, null=True)

    class Meta:

        abstract = True