"""
Canada-specific Form helpers
"""
from django.core.validators import EMPTY_VALUES
from django.forms import ValidationError
from django.forms.fields import Field,RegexField,Select
from django.utils.encoding import smart_unicode
from django.utils.translation import ugettext_lazy
import re
phone_digits_re = re.compile(r'^(?:1-?)?(\d{3})[-\.]?(\d{3})[-\.]?(\d{4})$')
sin_re = re.compile(r"^(\d{3})-(\d{3})-(\d{3})$")
class CAPostalCodeField(RegexField):
"""
Canadian postal code field.
Validates against known invalid characters: D, F, I, O, Q, U
Additionally the first character cannot be Z or W.
For more info see:
http://www.canadapost.ca/tools/pg/manual/PGaddress-e.asp#1402170
"""
default_error_messages = {
'invalid': _(u'Enter a postal code in the format XXX XXX.'),
}
def __init__(self, *args, **kwargs):
super(CAPostalCodeField, self).__init__(r'^[ABCEGHJKLMNPRSTVXY]\d[ABCEGHJKLMNPRSTVWXYZ] \d[ABCEGHJKLMNPRSTVWXYZ]\d$',
max_length=None, min_length=None, *args, **kwargs)
class CAPhoneNumberField(Field):
"""Canadian phone number field."""
default_error_messages = {
'invalid': u'Phone numbers must be in XXX-XXX-XXXX format.',
}
def clean(self, value):
"""Validate a phone number.
"""
super(CAPhoneNumberField, self).clean(value)
if value in EMPTY_VALUES:
return u''
value = re.sub('(\(|\)|\s+)', '', smart_unicode(value))
m = phone_digits_re.search(value)
if m:
return u'%s-%s-%s' % (m.group(1), m.group(2), m.group(3))
raise ValidationError(self.error_messages['invalid'])
class CAProvinceField(Field):
"""
A form field that validates its input is a Canadian province name or abbreviation.
It normalizes the input to the standard two-leter postal service
abbreviation for the given province.
"""
default_error_messages = {
'invalid': u'Enter a Canadian province or territory.',
}
def clean(self, value):
from ca_provinces import PROVINCES_NORMALIZED
super(CAProvinceField, self).clean(value)
if value in EMPTY_VALUES:
return u''
try:
value = value.strip().lower()
except AttributeError:
pass
else:
try:
return PROVINCES_NORMALIZED[value.strip().lower()].decode('ascii')
except KeyError:
pass
raise ValidationError(self.error_messages['invalid'])
class CAProvinceSelect(Select):
"""
A Select widget that uses a list of Canadian provinces and
territories as its choices.
"""
def __init__(self, attrs=None):
from ca_provinces import PROVINCE_CHOICES# relative import
super(CAProvinceSelect,self).__init__(attrs,choices=PROVINCE_CHOICES)
class CASocialInsuranceNumberField(Field):
"""
A Canadian Social Insurance Number (SIN).
Checks the following rules to determine whether the number is valid:
* Conforms to the XXX-XXX-XXX format.
* Passes the check digit process "Luhn Algorithm"
See: http://en.wikipedia.org/wiki/Social_Insurance_Number
"""
default_error_messages = {
'invalid': _('Enter a valid Canadian Social Insurance number in XXX-XXX-XXX format.'),
}
def clean(self, value):
super(CASocialInsuranceNumberField, self).clean(value)
if value in EMPTY_VALUES:
return u''
match = re.match(sin_re, value)
if not match:
raise ValidationError(self.error_messages['invalid'])
number = u'%s-%s-%s' % (match.group(1), match.group(2), match.group(3))
check_number = u'%s%s%s' % (match.group(1), match.group(2), match.group(3))
if not self.luhn_checksum_is_valid(check_number):
raise ValidationError(self.error_messages['invalid'])
return number
def luhn_checksum_is_valid(self, number):
"""
Checks to make sure that the SIN passes a luhn mod-10 checksum
See: http://en.wikipedia.org/wiki/Luhn_algorithm
"""
sum = 0
num_digits = len(number)
oddeven = num_digits & 1
for count in range(0, num_digits):
digit = int(number[count])
if not (( count & 1 ) ^ oddeven ):
digit = digit * 2
if digit > 9:
digit = digit - 9
sum = sum + digit
return ( (sum % 10) == 0 )
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