python/lib/django_1_4/tests/modeltests/custom_pk/fields.py

   1 import random
   2 import string
   3
   4 from django.db import models
   5
   6
   7 class MyWrapper(object):
   8     def __init__(self, value):
   9         self.value = value
  10
  11     def __repr__(self):
  12         return "<%s: %s>" % (self.__class__.__name__, self.value)
  13
  14     def __unicode__(self):
  15         return self.value
  16
  17     def __eq__(self, other):
  18         if isinstance(other, self.__class__):
  19             return self.value == other.value
  20         return self.value == other
  21
  22 class MyAutoField(models.CharField):
  23     __metaclass__ = models.SubfieldBase
  24
  25     def __init__(self, *args, **kwargs):
  26         kwargs['max_length'] = 10
  27         super(MyAutoField, self).__init__(*args, **kwargs)
  28
  29     def pre_save(self, instance, add):
  30         value = getattr(instance, self.attname, None)
  31         if not value:
  32             value = MyWrapper(''.join(random.sample(string.lowercase, 10)))
  33             setattr(instance, self.attname, value)
  34         return value
  35
  36     def to_python(self, value):
  37         if not value:
  38             return
  39         if not isinstance(value, MyWrapper):
  40             value = MyWrapper(value)
  41         return value
  42
  43     def get_db_prep_save(self, value, connection):
  44         if not value:
  45             return
  46         if isinstance(value, MyWrapper):
  47             return unicode(value)
  48         return value
  49
  50     def get_db_prep_value(self, value, connection, prepared=False):
  51         if not value:
  52             return
  53         if isinstance(value, MyWrapper):
  54             return unicode(value)
  55         return value