"""
South Africa-specific Form helpers
"""
from __future__ import unicode_literals
import re
from datetime import date
from django.core.validators import EMPTY_VALUES
from django.forms import ValidationError
from django.forms.fields import CharField, RegexField, Select
from django.utils.checksums import luhn
from django.utils.translation import gettext_lazy as _
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})')
[docs]class ZAIDField(CharField):
"""
A form field for South African ID numbers -- the checksum is validated
using the Luhn checksum, and uses a simlistic (read: not entirely accurate)
check for the birthdate
"""
default_error_messages = {
'invalid': _('Enter a valid South African ID number'),
}
def clean(self, value):
super(ZAIDField, self).clean(value)
if value in EMPTY_VALUES:
return ''
# strip spaces and dashes
value = value.strip().replace(' ', '').replace('-', '')
match = re.match(id_re, value)
if not match:
raise ValidationError(self.error_messages['invalid'])
g = match.groupdict()
try:
# The year 2000 is conveniently a leapyear.
# This algorithm will break in xx00 years which aren't leap years
# There is no way to guess the century of a ZA ID number
date(int(g['yy']) + 2000, int(g['mm']), int(g['dd']))
except ValueError:
raise ValidationError(self.error_messages['invalid'])
if not luhn(value):
raise ValidationError(self.error_messages['invalid'])
return value
[docs]class ZAPostCodeField(RegexField):
"""
A form field that validates input as a South African postcode. Valid
postcodes must have four digits.
"""
default_error_messages = {
'invalid': _('Enter a valid South African postal code'),
}
def __init__(self, max_length=None, min_length=None, *args, **kwargs):
super(ZAPostCodeField, self).__init__(r'^\d{4}$',
max_length, min_length, *args, **kwargs)
[docs]class ZAProvinceSelect(Select):
"""
A Select widget that uses a list of South African Provinces as its choices.
"""
def __init__(self, attrs=None):
from .za_provinces import PROVINCE_CHOICES
super(ZAProvinceSelect, self).__init__(attrs, choices=PROVINCE_CHOICES)