root/trunk/patForms/Rule/ConditionalRequired.php

<?php
/**
 * patForms Rule ConditionalRequired
 *
 * $Id$
 *
 * @package        patForms
 * @subpackage    Rules
 */

/**
 * patForms Rule ConditionalRequired
 *
 * This rule can be used to set the status of
 * some elements to required depending on the value
 * of another element.
 *
 * It has to be applied prior to validating the form.
 *
 * @package        patForms
 * @subpackage    Rules
 * @author        Stephan Schmidt <schst@php-tools.net>
 * @license        LGPL, see license.txt for details
 * @link        http://www.php-tools.net
 */
class patForms_Rule_ConditionalRequired extends patForms_Rule
{
   /**
    * fields that will be required
    * @access    private
    * @var        array
    */
    var $_requiredFields    =    array();

   /**
    * conditions
    * @access    private
    * @var        array
    */
    var $_conditions        =    array();

   /**
    * set the names of the fields that will be required
    *
    * @access    public
    * @param    array    required fields
    */
    function setRequiredFields( $fields )
    {
        $this->_requiredFields    =    $fields;
    }

   /**
    * add a condition
    *
    * @access    public
    * @param    string    condition field name
    * @param    mixed    condition value
    */
    function addCondition( $field, $value )
    {
        $this->_conditions[$field]    =    $value;
    }

   /**
    * method called by patForms or any patForms_Element to validate the
    * element or the form.
    *
    * @access    public
    * @param    object patForms    form object
    */
    function applyRule( &$form, $type = PATFORMS_RULE_BEFORE_VALIDATION )
    {
        $required    =    'yes';
        foreach( $this->_conditions as $field => $value )
        {
            $el        =    &$form->getElement( $field );
            $val    =    $el->getValue();
            if( $val != $value )
            {
                $required    =    'no';
                break;
            }
        }

        foreach( $this->_requiredFields as $field )
        {
            $el    =    &$form->getElement( $field );
            $el->setAttribute( 'required', $required );
        }
        
        return    true;
    }
}
?>