source: sandbox/workflow/branches/609/lib/WorkflowFactory.php @ 2207

<?php

/**
 * Specialization of the BaseFactory class.
 * This class is used to instantiate classes by
 * the workflow module (not by processes). You
 * cannot access this class directly, but requests
 * to the Factory frontend class in 'unsecured mode'
 * will be forwarded to this class.
 *
 * @author Pedro Eugênio Rocha
 * @package Factory
 */
class WorkflowFactory extends BaseFactory {


        /**
         * @var boolean $_instantiated Attribute that stores whether this
         *              class was instantiated or not. This is used to limit the
         *              instantiation of this class.
         * @access private
         * @static
         */
        private static $_instantiated = false;


        /**
         * Construct the class. This function will inform which classes
         * you will be able to instantiate and where to find it.
         * This function implements a kind of singleton design pattern too.
         * @access public
         */
        public function __construct() {

                /* don't let the user to instantiate this class more than once. */
                if (self::$_instantiated)
                        throw new Exception("You can't instantiate this class again.");

                /* registering allowed classes */
                $this->registerFileInfo('WorkflowObjects', 'class.WorkflowObjects.inc.php', 'inc');

                /* ok. no more instances of this class.. */
                self::$_instantiated = true;
        }
}

?>