text: """Iceland specific form helpers."""
  
  from __future__ import unicode_literals
  
  from django.core.validators import EMPTY_VALUES
  from django.forms import ValidationError
  from django.forms.fields import RegexField
  from django.forms.widgets import Select
  from django.utils.encoding import force_text
  from django.utils.translation import ugettext_lazy as _
  
  from localflavor.generic.forms import DeprecatedPhoneNumberFormFieldMixin
  
  from .is_postalcodes import IS_POSTALCODES
  
  
  class ISIdNumberField(RegexField):
      """
      Icelandic identification number (kennitala).
  
      This is a number every citizen of Iceland has.
      """
  
      default_error_messages = {
          'invalid': _('Enter a valid Icelandic identification number. The format is XXXXXX-XXXX.'),
          'checksum': _('The Icelandic identification number is not valid.'),
      }
  
      def __init__(self, max_length=11, min_length=10, *args, **kwargs):
          super(ISIdNumberField, self).__init__(r'^\d{6}(-| )?\d{4}$',
                                                max_length, min_length, *args, **kwargs)
  
      def clean(self, value):
          value = super(ISIdNumberField, self).clean(value)
  
          if value in EMPTY_VALUES:
              return ''
  
          value = self._canonify(value)
          if self._validate(value):
              return self._format(value)
          else:
              raise ValidationError(self.error_messages['checksum'])
  
      def _canonify(self, value):
          """Returns the value as only digits."""
          return value.replace('-', '').replace(' ', '')
  
      def _validate(self, value):
          """
          Takes in the value in canonical form and checks the verifier digit.
  
          The method is modulo 11.
          """
          check = [3, 2, 7, 6, 5, 4, 3, 2, 1, 0]
          return sum([int(value[i]) * check[i] for i in range(10)]) % 11 == 0
  
      def _format(self, value):
          """Takes in the value in canonical form and returns it in the common display format."""
          return force_text(value[:6] + '-' + value[6:])
  
  
  class ISPhoneNumberField(RegexField, DeprecatedPhoneNumberFormFieldMixin):
      """
      Icelandic phone number.
  
      Seven digits with an optional hyphen or space after the first three digits.
      """
  
      def __init__(self, max_length=8, min_length=7, *args, **kwargs):
          super(ISPhoneNumberField, self).__init__(r'^\d{3}(-| )?\d{4}$',
                                                   max_length, min_length, *args, **kwargs)
  
      def clean(self, value):
          value = super(ISPhoneNumberField, self).clean(value)
  
          if value in EMPTY_VALUES:
              return ''
  
          return value.replace('-', '').replace(' ', '')
  
  
  class ISPostalCodeSelect(Select):
      """A Select widget that uses a list of Icelandic postal codes as its choices."""
  
      def __init__(self, attrs=None):
          super(ISPostalCodeSelect, self).__init__(attrs, choices=IS_POSTALCODES)
  