"""
DE-specific Form helpers
"""
from __future__ import absolute_import, unicode_literals
import re
from django.core.validators import EMPTY_VALUES
from django.forms import ValidationError
from django.forms.fields import Field, RegexField, Select
from django.utils.translation import ugettext_lazy as _
from .de_states import STATE_CHOICES
id_re = re.compile(r"^(?P<residence>\d{10})(?P<origin>\w{1,3})[-\ ]?(?P<birthday>\d{7})[-\ ]?(?P<validity>\d{7})[-\ ]?(?P<checksum>\d{1})$")
[docs]class DEZipCodeField(RegexField):
"""
A form field that validates input as a German zip code. Valid codes
consist of five digits.
"""
default_error_messages = {
'invalid': _('Enter a zip code in the format XXXXX.'),
}
def __init__(self, max_length=None, min_length=None, *args, **kwargs):
super(DEZipCodeField, self).__init__(r'^\d{5}$',
max_length, min_length, *args, **kwargs)
[docs]class DEStateSelect(Select):
"""
A Select widget that uses a list of DE states as its choices.
"""
def __init__(self, attrs=None):
super(DEStateSelect, self).__init__(attrs, choices=STATE_CHOICES)
[docs]class DEIdentityCardNumberField(Field):
"""
A German identity card number.
Checks the following rules to determine whether the number is valid:
* Conforms to the XXXXXXXXXXX-XXXXXXX-XXXXXXX-X format.
* No group consists entirely of zeroes.
* Included checksums match calculated checksums
Algorithm is documented at http://de.wikipedia.org/wiki/Personalausweis
"""
default_error_messages = {
'invalid': _('Enter a valid German identity card number in XXXXXXXXXXX-XXXXXXX-XXXXXXX-X format.'),
}
def has_valid_checksum(self, number):
given_number, given_checksum = number[:-1], number[-1]
calculated_checksum = 0
fragment = ""
parameter = 7
for i in range(len(given_number)):
fragment = str(int(given_number[i]) * parameter)
if fragment.isalnum():
calculated_checksum += int(fragment[-1])
if parameter == 1:
parameter = 7
elif parameter == 3:
parameter = 1
elif parameter == 7:
parameter = 3
return str(calculated_checksum)[-1] == given_checksum
def clean(self, value):
super(DEIdentityCardNumberField, self).clean(value)
if value in EMPTY_VALUES:
return ''
match = re.match(id_re, value)
if not match:
raise ValidationError(self.error_messages['invalid'])
gd = match.groupdict()
residence, origin = gd['residence'], gd['origin']
birthday, validity, checksum = gd['birthday'], gd['validity'], gd['checksum']
if residence == '0000000000' or birthday == '0000000' or validity == '0000000':
raise ValidationError(self.error_messages['invalid'])
all_digits = "%s%s%s%s" % (residence, birthday, validity, checksum)
if (not self.has_valid_checksum(residence) or
not self.has_valid_checksum(birthday) or
not self.has_valid_checksum(validity) or
not self.has_valid_checksum(all_digits)):
raise ValidationError(self.error_messages['invalid'])
return '%s%s-%s-%s-%s' % (residence, origin, birthday, validity, checksum)