joomla下面插件开发

joomla插件实现原理是，使用观察者模式，逐一通知每个插件响应所注册的事件。对于权限验证模块，插件之间为或者的关系。假如

你开启了三个验证插件，那么只要有一个插件验证成功，那么返回的结果必然是验证通过。

插件的注册：插件注册，实际上是在数据库中插入一条记录，当被观察者发生某个事件后，观察者会去数据库中读取注册的插件，按照规则去通知插件。

我个人认为，插件之间的关系应该是可以设置的，这点没有去验证。如果插件返回值之间不存在任何关系的话，应该使用命令模式替代观察者模式。

以下是我写的一个验证插件。<?php/** * @version$Id: example.php 10381 2008-06-01 03:35:53Z pasamio $ * @packageJoomla * @subpackageJFramework * @copyrightCopyright (C) 2005 - 2008 Open Source Matters. All rights reserved. * @licenseGNU/GPL, see LICENSE.php * Joomla! is free software. This version may have been modified pursuant * to the GNU General Public License, and as distributed it includes or * is derivative of works licensed under the GNU General Public License or * other free or open source software licenses. * See COPYRIGHT.php for copyright notices and details. */// Check to ensure this file is included in Joomla!defined( '_JEXEC' ) or die( 'Restricted access' );jimport( 'joomla.plugin.plugin' );jimport('joomla.error.log');//require_once ( substr(dirname(__FILE__), '0','-23') .DS.'components' .DS.'com_euser'.DS.'config.class.php' );/** * Example Authentication Plugin * * @packageJoomla * @subpackageJFramework * @since 1.5 */class plgAuthenticationBplogin extends JPlugin{/** * Constructor * * For php4 compatability we must not use the __constructor as a constructor for plugins * because func_get_args ( void ) returns a copy of all passed arguments NOT references. * This causes problems with cross-referencing necessary for the observer design pattern. * * @paramobject$subjectThe object to observe * @paramarray$configAn array that holds the plugin configuration * @since1.5 */function plgAuthenticationExample(& $subject, $config){parent::__construct($subject, $config);}/** * This method should handle any authentication and report back to the subject * * @accesspublic * @paramarray$credentialsArray holding the user credentials * @paramarray$optionsArray of extra options * @paramobject$responseAuthentication response object * @returnboolean * @since1.5 */function onAuthenticate( $credentials, $options, &$response ){/* * Here you would do whatever you need for an authentication routine with the credentials * * In this example the mixed variable $return would be set to false * if the authentication routine fails or an integer userid of the authenticated * user if the routine passes */ // Joomla does not like blank passwordsif (empty($credentials['password'])){$response->status = JAUTHENTICATE_STATUS_FAILURE;$response->error_message = 'Empty password not allowed';return false;}// Initialize variables$conditions = '';// Get a database object$db = JFactory::getDBOORA();$query = “SELECT password,user_name FROM table WHERE user_name ='".$credentials['user']."'”$db->setQuery( $query );$result = $db->loadObject(); if(!empty($result)){$crypt= $result->password;$testcrypt = md5($credentials['password']);if ($crypt == $testcrypt) {//$user = JUser::getInstance($result->id); // Bring this in line with the rest of the system$response->jiaose = '';$response->username = $result->user_name;$response->status = JAUTHENTICATE_STATUS_SUCCESS;$response->error_message = ''; // $_SESSION['ServiceSequence'] = $as['ServiceSequence']; // $_SESSION['RetCode'] = $as['RetCode']; $_SESSION['username'] = $result->user_name; JRequest::setVar('return',$return); return true;} else {$response->status = JAUTHENTICATE_STATUS_FAILURE;$response->error_message = 'Invalid password';}}else{$response->status = JAUTHENTICATE_STATUS_FAILURE;$response->error_message = 'User does not exist';} return false;}}

 这个插件只监听了onAuthenticate事件。