## in models.py

class CustomerUserManager(BaseUserManager):

    def _create_user(self, national_id, password,
                     is_staff, is_superuser, **extra_fields):
        now = timezone.now()

        if not national_id:
            raise ValueError('Please provide a national id')

        national_id = self.normalize_national_id(national_id)
        user = self.model(national_id=national_id,
            is_staff=is_staff, is_active=True,
            is_superuser=is_superuser, last_login=now,
            created_at=now, **extra_fields)
        user.set_password(password)
        user.save(using=self._db)
        return user


    def create_user(self, national_id=None, password=None, **extra_fields):
        return self._create_user( national_id, password, False, False,**extra_fields)

    def create_superuser(self, national_id, password, **extra_fields):
        return self._create_user( national_id, password, True, True,
                                 **extra_fields)


    def normalize_national_id(cls, national_id):
        return national_id



class CustomUser(AbstractBaseUser,PermissionsMixin):
    national_id = models.CharField(max_length=12,unique=True)
    is_staff = models.BooleanField(_('staff status'), default=False,
        help_text=_('Designates whether the user can log into this admin site.'))
    is_active = models.BooleanField(_('active'), default=True,
        help_text=_('Designates whether this user should be treated as active. Unselect this instead of deleting accounts.'))
    created_at = models.DateTimeField(_('date created'), default=timezone.now)
    updated_at = models.DateTimeField(_('last modified'), default=timezone.now)

    USERNAME_FIELD = 'national_id'
    REQUIRED_FIELDS = []

    objects = CustomUserManager()

    def __unicode__(self):
        return self.national_id


# in settings.py
# assume the app name is app_1

AUTH_USER_MODEL = 'app_1.CustomUser'