Fixed #4122 -- Added Chilean localflavor. Thanks, marijn@metronomo.cl.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@5087 bcc190cf-cafb-0310-a4f2-bffc1f526a37

AUTHORS

@@ -150,6 +150,7 @@ answer newbie questions, and generally made Django that much better:
     Manuzhai
     Petar Marić <http://www.petarmaric.com/>
     Nuno Mariz <nmariz@gmail.com>
+    marijn@metronomo.cl
     mark@junklight.com
     Yasushi Masuda <whosaysni@gmail.com>
     mattycakes@gmail.com

django/contrib/localflavor/cl/forms.py

@@ -0,0 +1,77 @@
+"""
+Chile specific form helpers.
+"""
+from django.newforms import ValidationError
+from django.newforms.fields import RegexField, EMPTY_VALUES
+from django.utils.translation import gettext
+
+class CLRutField(RegexField):
+    """
+    Chilean "Rol Unico Tributario" (RUT) field. This is the Chilean national
+    identification number.
+
+    Samples for testing are available from
+    https://palena.sii.cl/cvc/dte/ee_empresas_emisoras.html
+    """
+    def __init__(self, *args, **kwargs):
+        if 'strict' in kwargs:
+            del kwargs['strict']
+            super(CLRutField, self).__init__(r'^(\d{1,2}\.)?\d{3}\.\d{3}-[\dkK]$',
+                error_message=gettext('Enter valid a Chilean RUT. The format is XX.XXX.XXX-X.'),
+                *args, **kwargs)
+        else:
+            # In non-strict mode, accept RUTs that validate but do not exist in
+            # the real world.
+            super(CLRutField, self).__init__(r'^[\d\.]{1,11}-?[\dkK]$', error_message=gettext(u'Enter valid a Chilean RUT'), *args, **kwargs)
+
+    def clean(self, value):
+        """
+        Check and clean the chilean rut.
+        """
+        super(CLRutField, self).clean(value)
+        if value in EMPTY_VALUES:
+            return u''
+        rut, verificador = self._canonify(value)
+        if self._algorithm(rut) == verificador:
+            return self._format(rut, verificador)
+        else:
+            raise ValidationError(u'The Chilean RUT is not valid.')
+
+    def _algorithm(self, rut):
+        """
+        Takes RUT in pure canonical form, calculates the verifier digit.
+        """
+        suma  = 0
+        multi = 2
+        for r in rut[::-1]:
+            suma  += int(r) * multi
+            multi += 1
+            if multi == 8:
+                multi = 2
+        return '0123456789K0'[11 - suma % 11]
+
+    def _canonify(self, rut):
+        """
+        Turns the RUT into one normalized format. Returns a (rut, verifier)
+        tuple.
+        """
+        rut = str(rut).replace(' ', '').replace('.', '').replace('-', '')
+        return rut[:-1], rut[-1]
+
+    def _format(self, code, verifier=None):
+        """
+        Formats the RUT from canonical form to the common string representation.
+        If verifier=None, then the last digit in 'code' is the verifier.
+        """
+        if verifier is None:
+            verifier = code[-1]
+            code = code[:-1]
+        while len(code) > 3 and '.' not in code[:3]:
+            pos = code.find('.')
+            if pos == -1:
+                new_dot = -3
+            else:
+                new_dot = pos - 3
+            code = code[:new_dot] + '.' + code[new_dot:]
+        return '%s-%s' % (code, verifier)
+