Django-1.2.1/django/contrib/localflavor/za/forms.py

   1 """
   2 South Africa-specific Form helpers
   3 """
   4
   5 from django.core.validators import EMPTY_VALUES
   6 from django.forms import ValidationError
   7 from django.forms.fields import Field, RegexField
   8 from django.utils.checksums import luhn
   9 from django.utils.translation import gettext as _
  10 import re
  11 from datetime import date
  12
  13 id_re = re.compile(r'^(?P<yy>\d\d)(?P<mm>\d\d)(?P<dd>\d\d)(?P<mid>\d{4})(?P<end>\d{3})')
  14
  15 class ZAIDField(Field):
  16     """A form field for South African ID numbers -- the checksum is validated
  17     using the Luhn checksum, and uses a simlistic (read: not entirely accurate)
  18     check for the birthdate
  19     """
  20     default_error_messages = {
  21         'invalid': _(u'Enter a valid South African ID number'),
  22     }
  23
  24     def clean(self, value):
  25         # strip spaces and dashes
  26         value = value.strip().replace(' ', '').replace('-', '')
  27
  28         super(ZAIDField, self).clean(value)
  29
  30         if value in EMPTY_VALUES:
  31             return u''
  32
  33         match = re.match(id_re, value)
  34
  35         if not match:
  36             raise ValidationError(self.error_messages['invalid'])
  37
  38         g = match.groupdict()
  39
  40         try:
  41             # The year 2000 is conveniently a leapyear.
  42             # This algorithm will break in xx00 years which aren't leap years
  43             # There is no way to guess the century of a ZA ID number
  44             d = date(int(g['yy']) + 2000, int(g['mm']), int(g['dd']))
  45         except ValueError:
  46             raise ValidationError(self.error_messages['invalid'])
  47
  48         if not luhn(value):
  49             raise ValidationError(self.error_messages['invalid'])
  50
  51         return value
  52
  53 class ZAPostCodeField(RegexField):
  54     default_error_messages = {
  55         'invalid': _(u'Enter a valid South African postal code'),
  56     }
  57
  58     def __init__(self, *args, **kwargs):
  59         super(ZAPostCodeField, self).__init__(r'^\d{4}$',
  60             max_length=None, min_length=None)