id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
26265	RendererMixin id_for_label causes HTML id uniqueness violation	Sven Coenye	Fyodor Ananiev	"When rendering a ChoiceField RadioSelect widget using form.as_p, the result is

{{{
<ul id=""id_field-field"">
  <li><label for=""id_field-field_0"">
      <input id=""id_field-field_0"" type=""radio"" value=""1"" name=""field-field"">
      ...
      </label>
  </li>
  <li><label for=""id_field-field_1"">...
  </li>
  ...
</ul>
}}}

Note that the id attribute of the ul element is id_field-field

When rendering the same RadioSelect field manually using 
{{{
<ul id=""{{field.id_for_label}}"">
  {% for choice in field %}
    <li><label for=""{{ choice.id_for_label }}"">{{ choice.tag }}</li>
  {% endfor %}
</ul>
}}}
the result is 
{{{
<ul id=""id_field-field_0"">
  <li><label for=""id_field-field_0"">
        <input id=""id_field-field_0"" type=""radio"" value=""1"" name=""field-field"">
        </label>
  </li>
  <li>...
  ...
</ul>
}}}

The outer ul element id now has the same id as the first radio button. This should not be.

The problem is caused by the implementation of id_for_label in forms.widgets.RendererMixin
{{{
def id_for_label(self, id_):
        # Widgets using this RendererMixin are made of a collection of
        # subwidgets, each with their own <label>, and distinct ID.
        # The IDs are made distinct by y ""_X"" suffix, where X is the zero-based
        # index of the choice field. Thus, the label for the main widget should
        # reference the first subwidget, hence the ""_0"" suffix.
        if id_:
            id_ += '_0'
        return id_
}}}
vs. what widgets.ChoiceFieldRenderer.render() does:
{{{
id_ = self.attrs.get('id')
...
return format_html(self.outer_html,
                           id_attr=format_html(' id=""{}""', id_) if id_ else '',
                           content=mark_safe('\n'.join(output)))
}}}
The docs [https://docs.djangoproject.com/en/1.9/ref/forms/widgets/#django.forms.RadioSelect] state
  The outer <ul> container will receive the id attribute defined on the widget.
which makes me believe render() is correct. Either way, I think these should be consistent with each other. If not, then the docs should mention using the ""name"" attribute to avoid the id collision."	Bug	closed	Forms	1.9	Normal	fixed		tedmx@…	Accepted	1	0	0	0	0	0