githubFork/roundcubemail.git

			@@ -3,7 +3,7 @@
			/*
			+-----------------------------------------------------------------------+
			\| This file is part of the Roundcube Webmail client \|
			\| Copyright (C) 2008-2011, The Roundcube Dev Team \|
			\| Copyright (C) 2008-2012, The Roundcube Dev Team \|
			\| \|
			\| Licensed under the GNU General Public License version 3 or \|
			\| any later version with exceptions for skins & plugins. \|
			@@ -17,9 +17,9 @@
			*/

			// location where plugins are loade from
			if (!defined('RCUBE_PLUGINS_DIR'))
			define('RCUBE_PLUGINS_DIR', RCUBE_INSTALL_PATH . 'plugins/');

			if (!defined('RCUBE_PLUGINS_DIR')) {
			define('RCUBE_PLUGINS_DIR', RCUBE_INSTALL_PATH . 'plugins/');
			}

			/**
			* The plugin loader and global API
			@@ -29,469 +29,596 @@
			*/
			class rcube_plugin_api
			{
			static protected $instance;
			static protected $instance;

			public $dir;
			public $url = 'plugins/';
			public $task = '';
			public $output;
			public $dir;
			public $url = 'plugins/';
			public $task = '';
			public $output;
			public $handlers = array();
			public $allowed_prefs = array();
			public $allowed_session_prefs = array();

			public $handlers = array();
			protected $plugins = array();
			protected $tasks = array();
			protected $actions = array();
			protected $actionmap = array();
			protected $objectsmap = array();
			protected $template_contents = array();
			protected $active_hook = false;
			protected $plugins = array();
			protected $tasks = array();
			protected $actions = array();
			protected $actionmap = array();
			protected $objectsmap = array();
			protected $template_contents = array();
			protected $active_hook = false;

			// Deprecated names of hooks, will be removed after 0.5-stable release
			protected $deprecated_hooks = array(
			'create_user' => 'user_create',
			'kill_session' => 'session_destroy',
			'upload_attachment' => 'attachment_upload',
			'save_attachment' => 'attachment_save',
			'get_attachment' => 'attachment_get',
			'cleanup_attachments' => 'attachments_cleanup',
			'display_attachment' => 'attachment_display',
			'remove_attachment' => 'attachment_delete',
			'outgoing_message_headers' => 'message_outgoing_headers',
			'outgoing_message_body' => 'message_outgoing_body',
			'address_sources' => 'addressbooks_list',
			'get_address_book' => 'addressbook_get',
			'create_contact' => 'contact_create',
			'save_contact' => 'contact_update',
			'contact_save' => 'contact_update',
			'delete_contact' => 'contact_delete',
			'manage_folders' => 'folders_list',
			'list_mailboxes' => 'mailboxes_list',
			'save_preferences' => 'preferences_save',
			'user_preferences' => 'preferences_list',
			'list_prefs_sections' => 'preferences_sections_list',
			'list_identities' => 'identities_list',
			'create_identity' => 'identity_create',
			'delete_identity' => 'identity_delete',
			'save_identity' => 'identity_update',
			'identity_save' => 'identity_update',
			// to be removed after 0.8
			'imap_init' => 'storage_init',
			'mailboxes_list' => 'storage_folders',
			'imap_connect' => 'storage_connect',
			);
			// Deprecated names of hooks, will be removed after 0.5-stable release
			protected $deprecated_hooks = array(
			'create_user' => 'user_create',
			'kill_session' => 'session_destroy',
			'upload_attachment' => 'attachment_upload',
			'save_attachment' => 'attachment_save',
			'get_attachment' => 'attachment_get',
			'cleanup_attachments' => 'attachments_cleanup',
			'display_attachment' => 'attachment_display',
			'remove_attachment' => 'attachment_delete',
			'outgoing_message_headers' => 'message_outgoing_headers',
			'outgoing_message_body' => 'message_outgoing_body',
			'address_sources' => 'addressbooks_list',
			'get_address_book' => 'addressbook_get',
			'create_contact' => 'contact_create',
			'save_contact' => 'contact_update',
			'contact_save' => 'contact_update',
			'delete_contact' => 'contact_delete',
			'manage_folders' => 'folders_list',
			'list_mailboxes' => 'mailboxes_list',
			'save_preferences' => 'preferences_save',
			'user_preferences' => 'preferences_list',
			'list_prefs_sections' => 'preferences_sections_list',
			'list_identities' => 'identities_list',
			'create_identity' => 'identity_create',
			'delete_identity' => 'identity_delete',
			'save_identity' => 'identity_update',
			'identity_save' => 'identity_update',
			// to be removed after 0.8
			'imap_init' => 'storage_init',
			'mailboxes_list' => 'storage_folders',
			'imap_connect' => 'storage_connect',
			);

			/**
			* This implements the 'singleton' design pattern
			*
			* @return rcube_plugin_api The one and only instance if this class
			*/
			static function get_instance()
			{
			if (!self::$instance) {
			self::$instance = new rcube_plugin_api();
			}

			return self::$instance;
			}


			/**
			* Private constructor
			*/
			protected function __construct()
			{
			$this->dir = slashify(RCUBE_PLUGINS_DIR);
			}


			/**
			* Initialize plugin engine
			*
			* This has to be done after rcmail::load_gui() or rcmail::json_init()
			* was called because plugins need to have access to rcmail->output
			*
			* @param object rcube Instance of the rcube base class
			* @param string Current application task (used for conditional plugin loading)
			*/
			public function init($app, $task = '')
			{
			$this->task = $task;
			$this->output = $app->output;

			// register an internal hook
			$this->register_hook('template_container', array($this, 'template_container_hook'));

			// maybe also register a shudown function which triggers shutdown functions of all plugin objects
			}


			/**
			* Load and init all enabled plugins
			*
			* This has to be done after rcmail::load_gui() or rcmail::json_init()
			* was called because plugins need to have access to rcmail->output
			*
			* @param array List of configured plugins to load
			* @param array List of plugins required by the application
			*/
			public function load_plugins($plugins_enabled, $required_plugins = array())
			{
			foreach ($plugins_enabled as $plugin_name) {
			$this->load_plugin($plugin_name);
			}

			// check existance of all required core plugins
			foreach ($required_plugins as $plugin_name) {
			$loaded = false;
			foreach ($this->plugins as $plugin) {
			if ($plugin instanceof $plugin_name) {
			$loaded = true;
			break;
			/**
			* This implements the 'singleton' design pattern
			*
			* @return rcube_plugin_api The one and only instance if this class
			*/
			static function get_instance()
			{
			if (!self::$instance) {
			self::$instance = new rcube_plugin_api();
			}
			}

			// load required core plugin if no derivate was found
			if (!$loaded)
			$loaded = $this->load_plugin($plugin_name);

			// trigger fatal error if still not loaded
			if (!$loaded) {
			rcube::raise_error(array('code' => 520, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Requried plugin $plugin_name was not loaded"), true, true);
			}
			return self::$instance;
			}
			}

			/**
			* Load the specified plugin
			*
			* @param string Plugin name
			* @return boolean True on success, false if not loaded or failure
			*/
			public function load_plugin($plugin_name)
			{
			static $plugins_dir;
			/**
			* Private constructor
			*/
			protected function __construct()
			{
			$this->dir = slashify(RCUBE_PLUGINS_DIR);
			}

			if (!$plugins_dir) {
			/**
			* Initialize plugin engine
			*
			* This has to be done after rcmail::load_gui() or rcmail::json_init()
			* was called because plugins need to have access to rcmail->output
			*
			* @param object rcube Instance of the rcube base class
			* @param string Current application task (used for conditional plugin loading)
			*/
			public function init($app, $task = '')
			{
			$this->task = $task;
			$this->output = $app->output;

			// register an internal hook
			$this->register_hook('template_container', array($this, 'template_container_hook'));

			// maybe also register a shudown function which triggers
			// shutdown functions of all plugin objects
			}

			/**
			* Load and init all enabled plugins
			*
			* This has to be done after rcmail::load_gui() or rcmail::json_init()
			* was called because plugins need to have access to rcmail->output
			*
			* @param array List of configured plugins to load
			* @param array List of plugins required by the application
			*/
			public function load_plugins($plugins_enabled, $required_plugins = array())
			{
			foreach ($plugins_enabled as $plugin_name) {
			$this->load_plugin($plugin_name);
			}

			// check existance of all required core plugins
			foreach ($required_plugins as $plugin_name) {
			$loaded = false;
			foreach ($this->plugins as $plugin) {
			if ($plugin instanceof $plugin_name) {
			$loaded = true;
			break;
			}
			}

			// load required core plugin if no derivate was found
			if (!$loaded) {
			$loaded = $this->load_plugin($plugin_name);
			}

			// trigger fatal error if still not loaded
			if (!$loaded) {
			rcube::raise_error(array(
			'code' => 520, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Requried plugin $plugin_name was not loaded"), true, true);
			}
			}
			}

			/**
			* Load the specified plugin
			*
			* @param string Plugin name
			*
			* @return boolean True on success, false if not loaded or failure
			*/
			public function load_plugin($plugin_name)
			{
			static $plugins_dir;

			if (!$plugins_dir) {
			$dir = dir($this->dir);
			$plugins_dir = unslashify($dir->path);
			}

			// plugin already loaded
			if ($this->plugins[$plugin_name] \|\| class_exists($plugin_name, false)) {
			return true;
			}

			$fn = $plugins_dir . DIRECTORY_SEPARATOR . $plugin_name
			. DIRECTORY_SEPARATOR . $plugin_name . '.php';

			if (file_exists($fn)) {
			include $fn;

			// instantiate class if exists
			if (class_exists($plugin_name, false)) {
			$plugin = new $plugin_name($this);
			// check inheritance...
			if (is_subclass_of($plugin, 'rcube_plugin')) {
			// ... task, request type and framed mode
			if ((!$plugin->task \|\| preg_match('/^('.$plugin->task.')$/i', $this->task))
			&& (!$plugin->noajax \|\| (is_object($this->output) && $this->output->type == 'html'))
			&& (!$plugin->noframe \|\| empty($_REQUEST['_framed']))
			) {
			$plugin->init();
			$this->plugins[$plugin_name] = $plugin;
			}

			if (!empty($plugin->allowed_prefs)) {
			$this->allowed_prefs = array_merge($this->allowed_prefs, $plugin->allowed_prefs);
			}

			return true;
			}
			}
			else {
			rcube::raise_error(array('code' => 520, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "No plugin class $plugin_name found in $fn"),
			true, false);
			}
			}
			else {
			rcube::raise_error(array('code' => 520, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Failed to load plugin file $fn"), true, false);
			}

			return false;
			}

			/**
			* Get information about a specific plugin.
			* This is either provided my a plugin's info() method or extracted from a package.xml or a composer.json file
			*
			* @param string Plugin name
			* @return array Meta information about a plugin or False if plugin was not found
			*/
			public function get_info($plugin_name)
			{
			static $composer_lock, $license_uris = array(
			'Apache' => 'http://www.apache.org/licenses/LICENSE-2.0.html',
			'Apache-2' => 'http://www.apache.org/licenses/LICENSE-2.0.html',
			'Apache-1' => 'http://www.apache.org/licenses/LICENSE-1.0',
			'Apache-1.1' => 'http://www.apache.org/licenses/LICENSE-1.1',
			'GPL' => 'http://www.gnu.org/licenses/gpl.html',
			'GPLv2' => 'http://www.gnu.org/licenses/gpl-2.0.html',
			'GPL-2.0' => 'http://www.gnu.org/licenses/gpl-2.0.html',
			'GPLv3' => 'http://www.gnu.org/licenses/gpl-3.0.html',
			'GPL-3.0' => 'http://www.gnu.org/licenses/gpl-3.0.html',
			'GPL-3.0+' => 'http://www.gnu.org/licenses/gpl.html',
			'GPL-2.0+' => 'http://www.gnu.org/licenses/gpl.html',
			'LGPL' => 'http://www.gnu.org/licenses/lgpl.html',
			'LGPLv2' => 'http://www.gnu.org/licenses/lgpl-2.0.html',
			'LGPLv2.1' => 'http://www.gnu.org/licenses/lgpl-2.1.html',
			'LGPLv3' => 'http://www.gnu.org/licenses/lgpl.html',
			'LGPL-2.0' => 'http://www.gnu.org/licenses/lgpl-2.0.html',
			'LGPL-2.1' => 'http://www.gnu.org/licenses/lgpl-2.1.html',
			'LGPL-3.0' => 'http://www.gnu.org/licenses/lgpl.html',
			'LGPL-3.0+' => 'http://www.gnu.org/licenses/lgpl.html',
			'BSD' => 'http://opensource.org/licenses/bsd-license.html',
			'BSD-2-Clause' => 'http://opensource.org/licenses/BSD-2-Clause',
			'BSD-3-Clause' => 'http://opensource.org/licenses/BSD-3-Clause',
			'FreeBSD' => 'http://opensource.org/licenses/BSD-2-Clause',
			'MIT' => 'http://www.opensource.org/licenses/mit-license.php',
			'PHP' => 'http://opensource.org/licenses/PHP-3.0',
			'PHP-3' => 'http://www.php.net/license/3_01.txt',
			'PHP-3.0' => 'http://www.php.net/license/3_0.txt',
			'PHP-3.01' => 'http://www.php.net/license/3_01.txt',
			);

			$dir = dir($this->dir);
			$plugins_dir = unslashify($dir->path);
			}
			$fn = unslashify($dir->path) . DIRECTORY_SEPARATOR . $plugin_name . DIRECTORY_SEPARATOR . $plugin_name . '.php';
			$info = false;

			// plugin already loaded
			if ($this->plugins[$plugin_name] \|\| class_exists($plugin_name, false))
			return true;
			if (!class_exists($plugin_name))
			include($fn);

			$fn = $plugins_dir . DIRECTORY_SEPARATOR . $plugin_name . DIRECTORY_SEPARATOR . $plugin_name . '.php';
			if (class_exists($plugin_name))
			$info = $plugin_name::info();

			if (file_exists($fn)) {
			include($fn);
			// fall back to composer.json file
			if (!$info) {
			$composer = INSTALL_PATH . "/plugins/$plugin_name/composer.json";
			if (file_exists($composer) && ($json = @json_decode(file_get_contents($composer), true))) {
			list($info['vendor'], $info['name']) = explode('/', $json['name']);
			$info['license'] = $json['license'];
			if ($license_uri = $license_uris[$info['license']])
			$info['license_uri'] = $license_uri;
			}

			// instantiate class if exists
			if (class_exists($plugin_name, false)) {
			$plugin = new $plugin_name($this);
			// check inheritance...
			if (is_subclass_of($plugin, 'rcube_plugin')) {
			// ... task, request type and framed mode
			if ((!$plugin->task \|\| preg_match('/^('.$plugin->task.')$/i', $this->task))
			&& (!$plugin->noajax \|\| (is_object($this->output) && $this->output->type == 'html'))
			&& (!$plugin->noframe \|\| empty($_REQUEST['_framed']))
			) {
			$plugin->init();
			$this->plugins[$plugin_name] = $plugin;
			// read local composer.lock file (once)
			if (!isset($composer_lock)) {
			$composer_lock = @json_decode(@file_get_contents(INSTALL_PATH . "/composer.lock"), true);
			if ($composer_lock['packages']) {
			foreach ($composer_lock['packages'] as $i => $package) {
			$composer_lock['installed'][$package['name']] = $package;
			}
			}
			return true;
			}

			// load additional information from local composer.lock file
			if ($lock = $composer_lock['installed'][$json['name']]) {
			$info['version'] = $lock['version'];
			$info['uri'] = $lock['homepage'] ? $lock['homepage'] : $lock['source']['uri'];
			$info['src_uri'] = $lock['dist']['uri'] ? $lock['dist']['uri'] : $lock['source']['uri'];
			}
			}
			else {
			rcube::raise_error(array('code' => 520, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "No plugin class $plugin_name found in $fn"), true, false);

			// fall back to package.xml file
			if (!$info) {
			$package = INSTALL_PATH . "/plugins/$plugin_name/package.xml";
			if (file_exists($package) && ($file = file_get_contents($package))) {
			$doc = new DOMDocument();
			$doc->loadXML($file);
			$xpath = new DOMXPath($doc);
			$xpath->registerNamespace('rc', "http://pear.php.net/dtd/package-2.0");

			// XPaths of plugin metadata elements
			$metadata = array(
			'name' => 'string(//rc:package/rc:name)',
			'version' => 'string(//rc:package/rc:version/rc:release)',
			'license' => 'string(//rc:package/rc:license)',
			'license_uri' => 'string(//rc:package/rc:license/@uri)',
			'src_uri' => 'string(//rc:package/rc:srcuri)',
			'uri' => 'string(//rc:package/rc:uri)',
			);

			foreach ($metadata as $key => $path) {
			$info[$key] = $xpath->evaluate($path);
			}

			// dependent required plugins (can be used, but not included in config)
			$deps = $xpath->evaluate('//rc:package/rc:dependencies/rc:required/rc:package/rc:name');
			for ($i = 0; $i < $deps->length; $i++) {
			$dn = $deps->item($i)->nodeValue;
			$info['requires'][] = $dn;
			}
			}
			}
			}
			else {
			rcube::raise_error(array('code' => 520, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Failed to load plugin file $fn"), true, false);

			return $info;
			}

			return false;
			}


			/**
			* Allows a plugin object to register a callback for a certain hook
			*
			* @param string $hook Hook name
			* @param mixed $callback String with global function name or array($obj, 'methodname')
			*/
			public function register_hook($hook, $callback)
			{
			if (is_callable($callback)) {
			if (isset($this->deprecated_hooks[$hook])) {
			rcube::raise_error(array('code' => 522, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Deprecated hook name. ".$hook.' -> '.$this->deprecated_hooks[$hook]), true, false);
			$hook = $this->deprecated_hooks[$hook];
			}
			$this->handlers[$hook][] = $callback;
			}
			else
			rcube::raise_error(array('code' => 521, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Invalid callback function for $hook"), true, false);
			}

			/**
			* Allow a plugin object to unregister a callback.
			*
			* @param string $hook Hook name
			* @param mixed $callback String with global function name or array($obj, 'methodname')
			*/
			public function unregister_hook($hook, $callback)
			{
			$callback_id = array_search($callback, $this->handlers[$hook]);
			if ($callback_id !== false) {
			unset($this->handlers[$hook][$callback_id]);
			}
			}


			/**
			* Triggers a plugin hook.
			* This is called from the application and executes all registered handlers
			*
			* @param string $hook Hook name
			* @param array $args Named arguments (key->value pairs)
			* @return array The (probably) altered hook arguments
			*/
			public function exec_hook($hook, $args = array())
			{
			if (!is_array($args))
			$args = array('arg' => $args);

			$args += array('abort' => false);
			$this->active_hook = $hook;

			foreach ((array)$this->handlers[$hook] as $callback) {
			$ret = call_user_func($callback, $args);
			if ($ret && is_array($ret))
			$args = $ret + $args;

			if ($args['abort'])
			break;
			/**
			* Allows a plugin object to register a callback for a certain hook
			*
			* @param string $hook Hook name
			* @param mixed $callback String with global function name or array($obj, 'methodname')
			*/
			public function register_hook($hook, $callback)
			{
			if (is_callable($callback)) {
			if (isset($this->deprecated_hooks[$hook])) {
			rcube::raise_error(array('code' => 522, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Deprecated hook name. "
			. $hook . ' -> ' . $this->deprecated_hooks[$hook]), true, false);
			$hook = $this->deprecated_hooks[$hook];
			}
			$this->handlers[$hook][] = $callback;
			}
			else {
			rcube::raise_error(array('code' => 521, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Invalid callback function for $hook"), true, false);
			}
			}

			$this->active_hook = false;
			return $args;
			}


			/**
			* Let a plugin register a handler for a specific request
			*
			* @param string $action Action name (_task=mail&_action=plugin.foo)
			* @param string $owner Plugin name that registers this action
			* @param mixed $callback Callback: string with global function name or array($obj, 'methodname')
			* @param string $task Task name registered by this plugin
			*/
			public function register_action($action, $owner, $callback, $task = null)
			{
			// check action name
			if ($task)
			$action = $task.'.'.$action;
			else if (strpos($action, 'plugin.') !== 0)
			$action = 'plugin.'.$action;

			// can register action only if it's not taken or registered by myself
			if (!isset($this->actionmap[$action]) \|\| $this->actionmap[$action] == $owner) {
			$this->actions[$action] = $callback;
			$this->actionmap[$action] = $owner;
			}
			else {
			rcube::raise_error(array('code' => 523, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Cannot register action $action; already taken by another plugin"), true, false);
			}
			}


			/**
			* This method handles requests like _task=mail&_action=plugin.foo
			* It executes the callback function that was registered with the given action.
			*
			* @param string $action Action name
			*/
			public function exec_action($action)
			{
			if (isset($this->actions[$action])) {
			call_user_func($this->actions[$action]);
			}
			else if (rcube::get_instance()->action != 'refresh') {
			rcube::raise_error(array('code' => 524, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "No handler found for action $action"), true, true);
			}
			}


			/**
			* Register a handler function for template objects
			*
			* @param string $name Object name
			* @param string $owner Plugin name that registers this action
			* @param mixed $callback Callback: string with global function name or array($obj, 'methodname')
			*/
			public function register_handler($name, $owner, $callback)
			{
			// check name
			if (strpos($name, 'plugin.') !== 0)
			$name = 'plugin.'.$name;

			// can register handler only if it's not taken or registered by myself
			if (is_object($this->output) && (!isset($this->objectsmap[$name]) \|\| $this->objectsmap[$name] == $owner)) {
			$this->output->add_handler($name, $callback);
			$this->objectsmap[$name] = $owner;
			}
			else {
			rcube::raise_error(array('code' => 525, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Cannot register template handler $name; already taken by another plugin or no output object available"), true, false);
			}
			}


			/**
			* Register this plugin to be responsible for a specific task
			*
			* @param string $task Task name (only characters [a-z0-9_.-] are allowed)
			* @param string $owner Plugin name that registers this action
			*/
			public function register_task($task, $owner)
			{
			// tasks are irrelevant in framework mode
			if (!class_exists('rcmail', false))
			return true;

			if ($task != asciiwords($task)) {
			rcube::raise_error(array('code' => 526, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Invalid task name: $task. Only characters [a-z0-9_.-] are allowed"), true, false);
			}
			else if (in_array($task, rcmail::$main_tasks)) {
			rcube::raise_error(array('code' => 526, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Cannot register taks $task; already taken by another plugin or the application itself"), true, false);
			}
			else {
			$this->tasks[$task] = $owner;
			rcmail::$main_tasks[] = $task;
			return true;
			/**
			* Allow a plugin object to unregister a callback.
			*
			* @param string $hook Hook name
			* @param mixed $callback String with global function name or array($obj, 'methodname')
			*/
			public function unregister_hook($hook, $callback)
			{
			$callback_id = array_search($callback, $this->handlers[$hook]);
			if ($callback_id !== false) {
			unset($this->handlers[$hook][$callback_id]);
			}
			}

			return false;
			}
			/**
			* Triggers a plugin hook.
			* This is called from the application and executes all registered handlers
			*
			* @param string $hook Hook name
			* @param array $args Named arguments (key->value pairs)
			*
			* @return array The (probably) altered hook arguments
			*/
			public function exec_hook($hook, $args = array())
			{
			if (!is_array($args)) {
			$args = array('arg' => $args);
			}

			$args += array('abort' => false);
			$this->active_hook = $hook;

			/**
			* Checks whether the given task is registered by a plugin
			*
			* @param string $task Task name
			* @return boolean True if registered, otherwise false
			*/
			public function is_plugin_task($task)
			{
			return $this->tasks[$task] ? true : false;
			}
			foreach ((array)$this->handlers[$hook] as $callback) {
			$ret = call_user_func($callback, $args);
			if ($ret && is_array($ret)) {
			$args = $ret + $args;
			}

			if ($args['break']) {
			break;
			}
			}

			/**
			* Check if a plugin hook is currently processing.
			* Mainly used to prevent loops and recursion.
			*
			* @param string $hook Hook to check (optional)
			* @return boolean True if any/the given hook is currently processed, otherwise false
			*/
			public function is_processing($hook = null)
			{
			return $this->active_hook && (!$hook \|\| $this->active_hook == $hook);
			}

			/**
			* Include a plugin script file in the current HTML page
			*
			* @param string $fn Path to script
			*/
			public function include_script($fn)
			{
			if (is_object($this->output) && $this->output->type == 'html') {
			$src = $this->resource_url($fn);
			$this->output->add_header(html::tag('script', array('type' => "text/javascript", 'src' => $src)));
			$this->active_hook = false;
			return $args;
			}
			}

			/**
			* Let a plugin register a handler for a specific request
			*
			* @param string $action Action name (_task=mail&_action=plugin.foo)
			* @param string $owner Plugin name that registers this action
			* @param mixed $callback Callback: string with global function name or array($obj, 'methodname')
			* @param string $task Task name registered by this plugin
			*/
			public function register_action($action, $owner, $callback, $task = null)
			{
			// check action name
			if ($task)
			$action = $task.'.'.$action;
			else if (strpos($action, 'plugin.') !== 0)
			$action = 'plugin.'.$action;

			/**
			* Include a plugin stylesheet in the current HTML page
			*
			* @param string $fn Path to stylesheet
			*/
			public function include_stylesheet($fn)
			{
			if (is_object($this->output) && $this->output->type == 'html') {
			$src = $this->resource_url($fn);
			$this->output->include_css($src);
			// can register action only if it's not taken or registered by myself
			if (!isset($this->actionmap[$action]) \|\| $this->actionmap[$action] == $owner) {
			$this->actions[$action] = $callback;
			$this->actionmap[$action] = $owner;
			}
			else {
			rcube::raise_error(array('code' => 523, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Cannot register action $action;"
			." already taken by another plugin"), true, false);
			}
			}
			}

			/**
			* This method handles requests like _task=mail&_action=plugin.foo
			* It executes the callback function that was registered with the given action.
			*
			* @param string $action Action name
			*/
			public function exec_action($action)
			{
			if (isset($this->actions[$action])) {
			call_user_func($this->actions[$action]);
			}
			else if (rcube::get_instance()->action != 'refresh') {
			rcube::raise_error(array('code' => 524, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "No handler found for action $action"), true, true);
			}
			}

			/**
			* Save the given HTML content to be added to a template container
			*
			* @param string $html HTML content
			* @param string $container Template container identifier
			*/
			public function add_content($html, $container)
			{
			$this->template_contents[$container] .= $html . "\n";
			}
			/**
			* Register a handler function for template objects
			*
			* @param string $name Object name
			* @param string $owner Plugin name that registers this action
			* @param mixed $callback Callback: string with global function name or array($obj, 'methodname')
			*/
			public function register_handler($name, $owner, $callback)
			{
			// check name
			if (strpos($name, 'plugin.') !== 0) {
			$name = 'plugin.' . $name;
			}

			// can register handler only if it's not taken or registered by myself
			if (is_object($this->output)
			&& (!isset($this->objectsmap[$name]) \|\| $this->objectsmap[$name] == $owner)
			) {
			$this->output->add_handler($name, $callback);
			$this->objectsmap[$name] = $owner;
			}
			else {
			rcube::raise_error(array('code' => 525, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Cannot register template handler $name;"
			." already taken by another plugin or no output object available"), true, false);
			}
			}

			/**
			* Returns list of loaded plugins names
			*
			* @return array List of plugin names
			*/
			public function loaded_plugins()
			{
			return array_keys($this->plugins);
			}
			/**
			* Register this plugin to be responsible for a specific task
			*
			* @param string $task Task name (only characters [a-z0-9_-] are allowed)
			* @param string $owner Plugin name that registers this action
			*/
			public function register_task($task, $owner)
			{
			// tasks are irrelevant in framework mode
			if (!class_exists('rcmail', false)) {
			return true;
			}

			if ($task != asciiwords($task, true)) {
			rcube::raise_error(array('code' => 526, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Invalid task name: $task."
			." Only characters [a-z0-9_.-] are allowed"), true, false);
			}
			else if (in_array($task, rcmail::$main_tasks)) {
			rcube::raise_error(array('code' => 526, 'type' => 'php',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Cannot register taks $task;"
			." already taken by another plugin or the application itself"), true, false);
			}
			else {
			$this->tasks[$task] = $owner;
			rcmail::$main_tasks[] = $task;
			return true;
			}

			/**
			* Callback for template_container hooks
			*
			* @param array $attrib
			* @return array
			*/
			protected function template_container_hook($attrib)
			{
			$container = $attrib['name'];
			return array('content' => $attrib['content'] . $this->template_contents[$container]);
			}
			return false;
			}

			/**
			* Checks whether the given task is registered by a plugin
			*
			* @param string $task Task name
			*
			* @return boolean True if registered, otherwise false
			*/
			public function is_plugin_task($task)
			{
			return $this->tasks[$task] ? true : false;
			}

			/**
			* Make the given file name link into the plugins directory
			*
			* @param string $fn Filename
			* @return string
			*/
			protected function resource_url($fn)
			{
			if ($fn[0] != '/' && !preg_match('\|^https?://\|i', $fn))
			return $this->url . $fn;
			else
			return $fn;
			}
			/**
			* Check if a plugin hook is currently processing.
			* Mainly used to prevent loops and recursion.
			*
			* @param string $hook Hook to check (optional)
			*
			* @return boolean True if any/the given hook is currently processed, otherwise false
			*/
			public function is_processing($hook = null)
			{
			return $this->active_hook && (!$hook \|\| $this->active_hook == $hook);
			}

			/**
			* Include a plugin script file in the current HTML page
			*
			* @param string $fn Path to script
			*/
			public function include_script($fn)
			{
			if (is_object($this->output) && $this->output->type == 'html') {
			$src = $this->resource_url($fn);
			$this->output->add_header(html::tag('script',
			array('type' => "text/javascript", 'src' => $src)));
			}
			}

			/**
			* Include a plugin stylesheet in the current HTML page
			*
			* @param string $fn Path to stylesheet
			*/
			public function include_stylesheet($fn)
			{
			if (is_object($this->output) && $this->output->type == 'html') {
			$src = $this->resource_url($fn);
			$this->output->include_css($src);
			}
			}

			/**
			* Save the given HTML content to be added to a template container
			*
			* @param string $html HTML content
			* @param string $container Template container identifier
			*/
			public function add_content($html, $container)
			{
			$this->template_contents[$container] .= $html . "\n";
			}

			/**
			* Returns list of loaded plugins names
			*
			* @return array List of plugin names
			*/
			public function loaded_plugins()
			{
			return array_keys($this->plugins);
			}

			/**
			* Callback for template_container hooks
			*
			* @param array $attrib
			* @return array
			*/
			protected function template_container_hook($attrib)
			{
			$container = $attrib['name'];
			return array('content' => $attrib['content'] . $this->template_contents[$container]);
			}

			/**
			* Make the given file name link into the plugins directory
			*
			* @param string $fn Filename
			* @return string
			*/
			protected function resource_url($fn)
			{
			if ($fn[0] != '/' && !preg_match('\|^https?://\|i', $fn))
			return $this->url . $fn;
			else
			return $fn;
			}
			}