Source for file WStepChangedListener.class.php

<?php
 
/**
 * @since Jul 22, 2005
 * @package polyphony.wizard.components
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: WStepChangedListener.class.php,v 1.4 2007/09/19 14:04:51 adamfranco Exp $
 */ 
 
require_once(POLYPHONY."/main/library/Wizard/Components/WizardEventListener.abstract.php");
 
/**
 * Supplies an event listener to a {@link Wizard} for update events, this will
 * pass the control back to the wizard if it would like it.
 * 
 * @since Jul 22, 2005
 * @package polyphony.wizard.components
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: WStepChangedListener.class.php,v 1.4 2007/09/19 14:04:51 adamfranco Exp $
 */
class WStepChangedListener 
    extends WizardEventListener 
    /* implements EventListener */ 
{    
    var $_added = false;
    var $_callBackFunction;
    
    /**
     * constructor
     * 
     * @param string $callBack the function to call when the event is called
     * @access public
     * @since 8/04/06
     */
    function WStepChangedListener ($callBack) {
        $this->_callBackFunction = $callBack;
    }    
        
    /**
     * Tells the wizard component to update itself - this may include getting
     * form post data or validation - whatever this particular component wants to
     * do every pageload.
     * @param string $fieldName The field name to use when outputting form data or
     *  similar parameters/information.
     * @access public
     * @return boolean - TRUE if everything is OK
     */
    function update ($fieldName) {
        $this->_attemptAdding();
    }
        
    /**
     * Returns the values of wizard-components. Should return an array if children are involved,
     * otherwise a whatever type of object is expected.
     * @access public
     * @return mixed 
     */
    function getAllValues () {
        return null;
    }
        
    /**
     * Handles an event triggered by an {@link EventTrigger}. The event type is passed in case this
     * particular EventListener is handling more than one type of event.
     * @param string $eventType 
     * @param ref object $source The source object of the event.
     * @param array $context An array of contextual parameters - the content will be dependent on the thrown event.
     * @access public
     * @return void 
     */
    function handleEvent ($eventType, $source, $context) {
        if ($eventType == 'edu.middlebury.polyphony.wizard.step_changed'){
            $action = $this->_callBackFunction.'($source, $context);';
            eval($action);                
        }
    }
}
?>