BR TelefoneField for Django model TelefoneField + Widget

telefone.py

from django.forms.widgets import TextInput
from django.contrib.db import models

import re


class TelefoneWidget(TextInput):

    def __init__(self, attrs=None):
        attrs_default = {'placeholder': 'xx-(x)xxxx-xxxx', 'maxlength': 13}
        if attrs:
            attrs_default.update(attrs)
        super(TelefoneWidget, self).__init__(attrs=attrs_default)


class TelefoneField(models.CharField):

    def formfield(self, *args, **kwargs):
        kwargs['widget'] = TelefoneWidget()
        return super(TelefoneField, self).formfield(*args, **kwargs)

    def clean(self, value, model_instance):
        value = value.replace(' ', '')
        regex = re.compile(r'^([0-9]{2})-(([0-9]{5})|([0-9]{4}))-([0-9]{4})$', re.IGNORECASE | re.UNICODE)

        if len(regex.findall(value)) != 1:
            raise ValidationError(u'Telefone %s inválido' % value)

        return super(TelefoneField, self).clean(value, model_instance)