Fixed #3847 -- Added validation support for Finnish social security numbers.

Thanks, karsu.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@4868 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/localflavor/fi/forms.py

@@ -2,8 +2,9 @@
 FI-specific Form helpers
 """
 
+import re
 from django.newforms import ValidationError
-from django.newforms.fields import RegexField, Select
+from django.newforms.fields import Field, RegexField, Select, EMPTY_VALUES
 from django.utils.translation import gettext
 
 class FIZipCodeField(RegexField):
@@ -20,3 +21,27 @@ class FIMunicipalitySelect(Select):
     def __init__(self, attrs=None):
         from fi_municipalities import MUNICIPALITY_CHOICES # relative import
         super(FIMunicipalitySelect, self).__init__(attrs, choices=MUNICIPALITY_CHOICES)
+
+class FISocialSecurityNumber(Field):
+    def clean(self, value):
+        super(FISocialSecurityNumber, self).clean(value)
+        if value in EMPTY_VALUES:
+ 	        return u''
+        
+        checkmarks = "0123456789ABCDEFHJKLMNPRSTUVWXY"
+        result = re.match(r"""^
+            (?P<date>([0-2]\d|3[01])
+            (0\d|1[012])
+            (\d{2}))
+            [A+-]
+            (?P<serial>(\d{3}))
+            (?P<chechsum>[%s])$""" % checkmarks, value, re.VERBOSE | re.IGNORECASE)
+        if not result:
+            raise ValidationError(gettext(u'Enter a valid Finnish social security number.'))
+        checksum = int(result.groupdict()['date'] + result.groupdict()['serial'])
+
+        if checkmarks[checksum % len(checkmarks)] == result.groupdict()['chechsum'].upper():
+            return u'%s' % value.upper()
+        
+        raise ValidationError(gettext(u'Enter a valid Finnish social security number.'))
+