<?php

class Qs_Form_Element_SelectOther extends Zend_Form_Element_Select
{
    const MODE_SELECT       = 'select';
    const MODE_SELECT_OTHER = 'selectOther';

    public $helper = 'formSelectOther';
    public $mode = self::MODE_SELECT_OTHER;

    public function isValid($value, $context = null)
    {
        if ($this->getAttrib('mode') == self::MODE_SELECT_OTHER) {
            $this->setRegisterInArrayValidator(false);
        }
        return parent::isValid($value, $context);
    }

    public function setValue($value)
    {
        /** @var Qs_Form_Decorator_HtmlTag $htmlTag */
        if (($htmlTag = $this->getDecorator('HtmlTag'))) {
            $htmlTag->toggleClass('other', null === $this->getMultiOption($value));
        }
        return parent::setValue($value);
    }
}