--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/contrib/localflavor/ch/forms.py	Fri Jul 18 18:22:23 2008 +0000
@@ -0,0 +1,118 @@
+"""
+Swiss-specific Form helpers
+"""
+
+from django.newforms import ValidationError
+from django.newforms.fields import Field, RegexField, Select, EMPTY_VALUES
+from django.utils.encoding import smart_unicode
+from django.utils.translation import ugettext
+import re
+
+id_re = re.compile(r"^(?P<idnumber>\w{8})(?P<pos9>(\d{1}|<))(?P<checksum>\d{1})$")
+phone_digits_re = re.compile(r'^0([1-9]{1})\d{8}$')
+
+class CHZipCodeField(RegexField):
+    default_error_messages = {
+        'invalid': ugettext('Enter a zip code in the format XXXX.'),
+    }
+
+    def __init__(self, *args, **kwargs):
+        super(CHZipCodeField, self).__init__(r'^\d{4}$',
+        max_length=None, min_length=None, *args, **kwargs)
+
+class CHPhoneNumberField(Field):
+    """
+    Validate local Swiss phone number (not international ones)
+    The correct format is '0XX XXX XX XX'.
+    '0XX.XXX.XX.XX' and '0XXXXXXXXX' validate but are corrected to
+    '0XX XXX XX XX'.
+    """
+    default_error_messages = {
+        'invalid': 'Phone numbers must be in 0XX XXX XX XX format.',
+    }
+
+    def clean(self, value):
+        super(CHPhoneNumberField, 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 %s' % (value[0:3], value[3:6], value[6:8], value[8:10])
+        raise ValidationError(self.error_messages['invalid'])
+
+class CHStateSelect(Select):
+    """
+    A Select widget that uses a list of CH states as its choices.
+    """
+    def __init__(self, attrs=None):
+        from ch_states import STATE_CHOICES # relative import
+        super(CHStateSelect, self).__init__(attrs, choices=STATE_CHOICES)
+
+class CHIdentityCardNumberField(Field):
+    """
+    A Swiss identity card number.
+
+    Checks the following rules to determine whether the number is valid:
+
+        * Conforms to the X1234567<0 or 1234567890 format.
+        * Included checksums match calculated checksums
+
+    Algorithm is documented at http://adi.kousz.ch/artikel/IDCHE.htm
+    """
+    default_error_messages = {
+        'invalid': ugettext('Enter a valid Swiss identity or passport card number in X1234567<0 or 1234567890 format.'),
+    }
+
+    def has_valid_checksum(self, number):
+        given_number, given_checksum = number[:-1], number[-1]
+        new_number = given_number
+        calculated_checksum = 0
+        fragment = ""
+        parameter = 7
+
+        first = str(number[:1])
+        if first.isalpha():
+            num = ord(first.upper()) - 65
+            if num < 0 or num > 8:
+                return False
+            new_number = str(num) + new_number[1:]
+            new_number = new_number[:8] + '0'
+
+        if not new_number.isdigit():
+            return False
+
+        for i in range(len(new_number)):
+          fragment = int(new_number[i])*parameter
+          calculated_checksum += fragment
+
+          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(CHIdentityCardNumberField, self).clean(value)
+        if value in EMPTY_VALUES:
+            return u''
+
+        match = re.match(id_re, value)
+        if not match:
+            raise ValidationError(self.error_messages['invalid'])
+
+        idnumber, pos9, checksum = match.groupdict()['idnumber'], match.groupdict()['pos9'], match.groupdict()['checksum']
+
+        if idnumber == '00000000' or \
+           idnumber == 'A0000000':
+            raise ValidationError(self.error_messages['invalid'])
+
+        all_digits = "%s%s%s" % (idnumber, pos9, checksum)
+        if not self.has_valid_checksum(all_digits):
+            raise ValidationError(self.error_messages['invalid'])
+
+        return u'%s%s%s' % (idnumber, pos9, checksum)
+