Source for file HandlerChain.inc

<?php
  /**
   * Generic HandlerChain
   *
   * This file is part of CompInaBox.
   * @copyright CompInaBox Copyright 2001-2005. Eric D. Nielsen, All rights reserverd.
   * @license http://opensource.org/licenses/gpl-license.php GNU Public License
   *
   * @author Eric D. Nielsen <nielsene@alum.mit.edu>
   * @package InputControllers
  */
  /**
   * The Generic HandlerChain
   *
   * @package InputControllers
   */
require_once("conf/tools/defines.inc");
class HandlerChain {
 
  var $_handlers;
  function HandlerChain($filename="") {
    $this->_handlers=array();
    if ($filename!="") 
      $this->initHandlers(file(CIB_BASE."include/conf/handlers/$filename.setup"));
  }
  
  function addHandler(&$handler) {
    $this->_handlers[]=&$handler;
  }
 
  function invoke(&$con, $req) {
    $numHandlers=count($this->_handlers);
    $view="";
    for ($i=0;$i<$numHandlers;$i++) {
      $aHandler=&$this->_handlers[$i];
      if ($aHandler->canHandle($con,$req)) {
    $view=$aHandler->execute($con,$req);
    break;
      }
    }
    return $view;
 
  }
 
  function initHandlers($config) {
    foreach ($config as $aLine) {
      if ($aLine=="") continue;
      $components = explode(" ",$aLine);
      $type = $components[0];
      switch ($type) {
      case "AccessControl": 
    $authRequired = in_array("AuthenticationRequired",$components);
    $levelIndex = array_search("Levels",$components);
    if ($levelIndex!==FALSE) {
      $permissions=& new Permissions($components[$levelIndex+1]);
      $handler = &new AccessDeniedHandler($authRequired,$permissions);
    } else {    
      $handler =& new AccessDeniedHandler($authRequired);
    }
    $this->addHandler($handler); break;
      }
    }
    return;
  }
}
?>