class.ilAppEventHandler.php

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<?php
/*
    +-----------------------------------------------------------------------------+
    | ILIAS open source                                                           |
    +-----------------------------------------------------------------------------+
    | Copyright (c) 1998-2006 ILIAS open source, University of Cologne            |
    |                                                                             |
    | This program is free software; you can redistribute it and/or               |
    | modify it under the terms of the GNU General Public License                 |
    | as published by the Free Software Foundation; either version 2              |
    | of the License, or (at your option) any later version.                      |
    |                                                                             |
    | This program is distributed in the hope that it will be useful,             |
    | but WITHOUT ANY WARRANTY; without even the implied warranty of              |
    | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               |
    | GNU General Public License for more details.                                |
    |                                                                             |
    | You should have received a copy of the GNU General Public License           |
    | along with this program; if not, write to the Free Software                 |
    | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. |
    +-----------------------------------------------------------------------------+
*/

class ilAppEventHandler
{
    protected $db;

    protected $listener; // [array]

    protected $logger;
    
    public function __construct()
    {
        global $DIC;

        $this->db = $DIC->database();
        $this->initListeners();

        $this->logger = \ilLoggerFactory::getLogger('evnt');
    }

    protected function initListeners()
    {
        require_once('./Services/GlobalCache/classes/class.ilGlobalCache.php');
        $ilGlobalCache = ilGlobalCache::getInstance(ilGlobalCache::COMP_EVENTS);
        $cached_listeners = $ilGlobalCache->get('listeners');
        if (is_array($cached_listeners)) {
            $this->listener = $cached_listeners;

            return;
        }

        $ilDB = $this->db;

        $this->listener = array();

        $sql = "SELECT * FROM il_event_handling" .
            " WHERE type = " . $ilDB->quote("listen", "text");
        $res = $ilDB->query($sql);
        while ($row = $ilDB->fetchAssoc($res)) {
            $this->listener[$row["id"]][] = $row["component"];
        }

        $ilGlobalCache->set('listeners', $this->listener);
    }



    public function raise($a_component, $a_event, $a_parameter = "")
    {
        $this->logger->debug(sprintf(
            "Received event '%s' from component '%s'.",
            $a_event,
            $a_component
        ));

        // lazy transforming event data to string
        $this->logger->debug(new class($a_parameter) {
            protected $parameter;

            public function __construct($parameter)
            {
                $this->parameter = $parameter;
            }

            public function __toString()
            {
                if (is_object($this->parameter)) {
                    return 'Event data class: ' . get_class($this->parameter);
                }

                return 'Event data size: ' . sizeof($this->parameter);
                //return 'Event data: ' . print_r($this->parameter, 1);
            }
        });

        $this->logger->debug("Started event propagation for event listeners ...");

        if (is_array($this->listener[$a_component])) {
            foreach ($this->listener[$a_component] as $listener) {
                // Allow listeners like Services/WebServices/ECS
                $last_slash = strripos($listener, '/');
                $comp = substr($listener, 0, $last_slash);

                // any kind of plugins with events in their plugin.xml
                if ($comp == 'Plugins') {
                    $name = substr($listener, $last_slash + 1);

                    foreach (ilPluginAdmin::getActivePlugins() as $pdata) {
                        if ($pdata['name'] == $name) {
                            $plugin = ilPluginAdmin::getPluginObject(
                                $pdata['component_type'],
                                $pdata['component_name'],
                                $pdata['slot_id'],
                                $pdata['name']
                            );

                            $plugin->handleEvent($a_component, $a_event, $a_parameter);
                        }
                    }
                } else {
                    $class = 'il' . substr($listener, $last_slash + 1) . 'AppEventListener';
                    $file = "./" . $listener . "/classes/class." . $class . ".php";

                    // if file exists, call listener
                    if (is_file($file)) {
                        include_once($file);
                        call_user_func(array($class, 'handleEvent'), $a_component, $a_event, $a_parameter);
                    }
                }
            }
        }

        $this->logger->debug("Finished event listener handling, started event propagation for event hook plugins ...");

        // get all event hook plugins and forward the event to them
        include_once("./Services/Component/classes/class.ilPluginAdmin.php");
        $plugins = ilPluginAdmin::getActivePluginsForSlot("Services", "EventHandling", "evhk");
        foreach ($plugins as $pl) {
            $plugin = ilPluginAdmin::getPluginObject(
                "Services",
                "EventHandling",
                "evhk",
                $pl
            );
            $plugin->handleEvent($a_component, $a_event, $a_parameter);
        }

        $this->logger->debug("Finished event hook plugin handling, started event propagation for workflow engine ...");
    }
}