Source for file ClassesActionSource.class.php

<?php
 
require_once (HARMONI."actionHandler/ActionSource.abstract.php");
 
/**
 * The ClassesActionSource looks for actions as classes located within include files.
 * The classes each have a special method as defined by {@link ACTIONS_CLASSES_METHOD}
 * which is called in order to execute the action.
 *
 * @package harmoni.actions.sources
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: ClassesActionSource.class.php,v 1.11 2007/09/04 20:25:29 adamfranco Exp $
 */
class ClassesActionSource 
    extends ActionSource
{
 
    /**
     * @var string $_basePath The base path on the filesystem to look for module
     *         folders.
     * @access private
     ***/
    var $_basePath;
    
    /**
     * @var string $_fileExtension The extension to add onto action names to locate
     *         their associated files.
     * @access private
     ***/
    var $_fileExtension;
    
    /**
     * @var string $_classNameSuffix Suffix to append to the name of classes
     * @access private
     */
    var $_classNameSuffix;
    
    /**
     * Constructor
     * @param string $basePath The base path on the filesystem which contains the
     *          module folders.
     * @param string $fileExtension The extension to add onto action names to find
     *         the files, such that the action "welcome" might look for a file named
     *         "welcome.class.php" with a file extension of ".class.php".
     * @param optional string $classNameSuffix A string to append to the names of
     *         action classes to prevent namespace conflicts with libraries/other
     *         classes. For example, with a suffix of 'Action', an action 'welcome'
     *         would correspond to a class named 'welcomeAction'.
     *
     * @return void 
     * @access public
     */
    function ClassesActionSource($basePath, $fileExtension, $classNameSuffix = '') {
        $this->_basePath = ereg_replace(DIRECTORY_SEPARATOR."$", "", $basePath);
        $this->_fileExtension = $fileExtension;
        $this->_classNameSuffix = $classNameSuffix;
    }
    
    /**
     * Checks to see if a given modules/action pair exists for execution within this source.
     * @param string $module 
     * @param string $action 
     * @access public
     * @return boolean 
     */
    function actionExists($module, $action)
    {
        $fullPath = $this->_mkFullPath($module, $action);
        return file_exists($fullPath);
    }
    
    /**
     * Makes a full pathname to an action file.
     * @access private
     * @return string 
     */
    function _mkFullPath($module, $action)
    {
        return $this->_basePath . DIRECTORY_SEPARATOR . $module . DIRECTORY_SEPARATOR . $action . $this->_fileExtension;
    }
    
    /**
     * Executes the specified action in the specified module, using the Harmoni object as a base.
     * @param string $module The module in which to execute.
     * @param string $action The specific action to execute.
     * @param ref object $harmoni A reference to a {@link Harmoni} object.
     * @access public
     * @return ref mixed A {@link Layout} or TRUE/FALSE
     */
    function executeAction($module, $action, $harmoni)
    {
        $fullPath = $this->_mkFullPath($module, $action);
        if (!$this->actionExists($module, $action)) {
            throwError( new Error("ClassesActionSource::executeAction($module, $action) - could not proceed because the file to include does not exist!", "ActionHandler", true));
        }
        
        include_once($fullPath);
        
        $actionClassname = $action.$this->_classNameSuffix;
        
        if (!class_exists($actionClassname)) {
            throwError( new Error("ClassesActionSource::executeAction($module, $action) - could not proceed because the class name '$action' is not defined!","ActionHandler", true));
        }
        
        $class = new $actionClassname;
        
        $method = ACTIONS_CLASSES_METHOD;
        
        if (!method_exists($class, $method)) {
            throwError( new Error("ClassesActionSource::executeAction($module, $action) - could not proceed because the method '$method()' is not defined in the class '$action'!","ActionHandler", true));
        }
        
        $result =$class->$method($harmoni);
        
        return $result;
    }
}