'Render the filter widgets without FORM wrapper, e.g. to
embed them as fieldset in another form.
@param resource: the S3Resource
@param get_vars: the request GET vars (URL query dict)
@param alias: the resource alias to use in widgets'

def fields(self, resource, get_vars=None, alias=None):

    formstyle = self.opts.get('formstyle', None)
    if (not formstyle):
        formstyle = current.deployment_settings.get_ui_filter_formstyle()
    rows = self._render_widgets(resource, get_vars=get_vars, alias=alias, formstyle=formstyle)
    controls = self._render_controls(resource)
    if controls:
        rows.append(formstyle(None, '', controls, ''))
    if rows:
        elements = rows[0]
        if (not isinstance(elements, (list, tuple))):
            elements = elements.elements()
        n = len(elements)
        if (((n > 0) and (elements[0].tag == 'tr')) or ((n > 1) and (elements[0].tag == '') and (elements[1].tag == 'tr'))):
            fields = TABLE(TBODY(rows))
        else:
            fields = DIV(rows)
    return fields
