Need a Zend_Form_Element that only stores a value - php

Question

I have an array of options for a select list.
$options = array( 1=>'Option1', 2=>... );
But if I only have one option, I rather want either:
A hidden <input type="hidden" name="opt" value="2"/> with a validator requiring the posted value to be 2
No output. The value will only be stored in the form_element/form until requested by $form->getValues()
This code is a non-working example of what I want: ($this is a Zend_Form object)
$first_val = reset(array_keys($options));
if( count($options) > 1 )
$this->addElement('select', 'opt', array(
'multiOptions' => $options,
'label' => 'Options',
'value' => $first_val,
'required' => true ));
else
$this->addElement('hidden', 'opt', array(
'required' => true,
'value' => $first_val ));
However, the value will not validate to $first_val. Anyone may change the hidden value, allowing them to inject invalid values. This is not acceptable.
Help?

Answer 1

your code is missing a validator, e.g. Zend_Validate_Identical

Answer 2

I created a custom Zend_Form_Element that does exactly what I want. Maybe someone else might find it useful:
<?php
require_once 'Zend/Form/Element.php';
/**
* Class that will automatically validate against currently set value.
*/
class myApp_Element_Stored extends Zend_Form_Element
{
/**
* Use formHidden view helper by default
* #var string
*/
public $helper = 'formHidden';
/**
* Locks the current value for validation
*/
public function lockValue()
{
$this->addValidator('Identical', true, (string)$this->getValue());
return $this;
}
public function isValid($value, $context = null)
{
$this->lockValue();
return parent::isValid($value, $context);
}
}
?>