from django import forms
from django.utils.encoding import force_unicode
from django.utils.html import conditional_escape, escape

class DisableableSelectWidget(forms.Select):
    def __init__(self, attrs=None, disabled_choices=(), choices=()):
        super(DisableableSelectWidget, self).__init__(attrs, choices)
        self.disabled_choices = list(disabled_choices)

    def render_option(self, selected_choices, option_value, option_label):
        option_value = force_unicode(option_value)
        if option_value in selected_choices:
            selected_html = u' selected="selected"'
            if not self.allow_multiple_selected:
                # Only allow for a single selection.
                selected_choices.remove(option_value)
        else:
            selected_html = ''
        if option_value in self.disabled_choices:
            disabled_html = u' disabled="disabled"'
        else:
            disabled_html = ''
        return u'<option value="%s"%s%s>%s</option>' % (
            escape(option_value), selected_html, disabled_html,
            conditional_escape(force_unicode(option_label)))