1 """

     2 base abstract models

     3 """

     4 import uuid

     5 

     6 from concurrency.fields import AutoIncVersionField

     7 from django.db import models

     8 from django.utils.translation import ugettext_lazy as _

     9 

    10 

    11 class ModelManager(models.Manager):

    12     def get_by_natural_key(self, ext_id):

    13         return self.get(ext_id=ext_id)

    14 

    15 class Model(models.Model):

    16     objects = ModelManager()

    17 

    18     created = models.DateTimeField(auto_now_add=True, verbose_name=_('Model|created'))

    19     updated = models.DateTimeField(auto_now=True, verbose_name=_('Model|updated'))

    20     ext_id = models.UUIDField(unique=True, default=uuid.uuid4, verbose_name=_('Model|ext_id'))

    21     version = AutoIncVersionField(verbose_name=_('Model|version'))

    22 

    23     def natural_key(self):

    24         return (self.ext_id, )

    25 

    26     class Meta:

    27         abstract = True