"""China(mainland)-specific Form helpers."""
import re
from django.forms import ValidationError
from django.forms.fields import CharField, RegexField, Select
from django.utils.translation import gettext_lazy as _
from .cn_provinces import CN_PROVINCE_CHOICES
__all__ = (
'CNProvinceSelect',
'CNPostCodeField',
'CNIDCardField',
)
ID_CARD_RE = r'^\d{15}(\d{2}[0-9xX])?$'
POST_CODE_RE = r'^\d{6}$'
# Valid location code used in id card checking algorithm
CN_LOCATION_CODES = (
11, # Beijing
12, # Tianjin
13, # Hebei
14, # Shanxi
15, # Nei Mongol
21, # Liaoning
22, # Jilin
23, # Heilongjiang
31, # Shanghai
32, # Jiangsu
33, # Zhejiang
34, # Anhui
35, # Fujian
36, # Jiangxi
37, # Shandong
41, # Henan
42, # Hubei
43, # Hunan
44, # Guangdong
45, # Guangxi
46, # Hainan
50, # Chongqing
51, # Sichuan
52, # Guizhou
53, # Yunnan
54, # Xizang
61, # Shaanxi
62, # Gansu
63, # Qinghai
64, # Ningxia
65, # Xinjiang
71, # Taiwan
81, # Hong Kong
91, # Macao
)
[docs]class CNProvinceSelect(Select):
"""A select widget providing the list of provinces and districts in People's Republic of China as choices."""
def __init__(self, attrs=None):
super().__init__(attrs, choices=CN_PROVINCE_CHOICES)
[docs]class CNPostCodeField(RegexField):
"""
A form field that validates input as postal codes in mainland China.
Valid codes are in the format of XXXXXX where X is a digit.
"""
default_error_messages = {
'invalid': _('Enter a post code in the format XXXXXX.'),
}
def __init__(self, **kwargs):
super().__init__(POST_CODE_RE, **kwargs)
[docs]class CNIDCardField(CharField):
"""
A form field that validates input as a Resident Identity Card (PRC) number.
This field would check the following restrictions:
* the length could only be 15 or 18;
* if the length is 18, the last character can be x or X;
* has a valid checksum (only for those with a length of 18);
* has a valid date of birth;
* has a valid province.
The checksum algorithm is described in GB11643-1999.
See: http://en.wikipedia.org/wiki/Resident_Identity_Card#Identity_card_number
"""
default_error_messages = {
'invalid': _('ID Card Number consists of 15 or 18 digits.'),
'checksum': _('Invalid ID Card Number: Wrong checksum'),
'birthday': _('Invalid ID Card Number: Wrong birthdate'),
'location': _('Invalid ID Card Number: Wrong location code'),
}
def __init__(self, max_length=18, min_length=15, **kwargs):
super().__init__(max_length=max_length, min_length=min_length, **kwargs)
[docs] def clean(self, value):
"""Check whether the input is a valid ID Card Number."""
# Check the length of the ID card number.
value = super().clean(value)
if value in self.empty_values:
return value
# Check whether this ID card number has valid format
if not re.match(ID_CARD_RE, value):
raise ValidationError(self.error_messages['invalid'], code='invalid')
# Check the birthday of the ID card number.
if not self.has_valid_birthday(value):
raise ValidationError(self.error_messages['birthday'], code='birthday' )
# Check the location of the ID card number.
if not self.has_valid_location(value):
raise ValidationError(self.error_messages['location'], code='location')
# Check the checksum of the ID card number.
value = value.upper()
if not self.has_valid_checksum(value):
raise ValidationError(self.error_messages['checksum'], code='checksum')
return '%s' % value
[docs] def has_valid_birthday(self, value):
"""This method grabs the date of birth from the ID card number and test whether it is a valid date."""
from datetime import datetime
if len(value) == 15:
# 1st generation ID card
time_string = value[6:12]
format_string = "%y%m%d"
else:
# 2nd generation ID card
time_string = value[6:14]
format_string = "%Y%m%d"
try:
datetime.strptime(time_string, format_string)
return True
except ValueError:
# invalid date
return False
[docs] def has_valid_location(self, value):
"""This method checks if the first two digits in the ID Card are valid province code."""
return int(value[:2]) in CN_LOCATION_CODES
[docs] def has_valid_checksum(self, value):
"""This method checks if the last letter/digit is valid according to GB11643-1999."""
# If the length of the number is not 18, then the number is a 1st
# generation ID card number, and there is no checksum to be checked.
if len(value) != 18:
return True
checksum_index = sum(
map(lambda a, b: a * (ord(b) - ord('0')),
(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2),
value[:17],),
) % 11
return '10X98765432'[checksum_index] == value[-1]