. namespace core\event; defined('MOODLE_INTERNAL') || die(); /** * New event manager class. * * @package core * @since Moodle 2.6 * @copyright 2013 Petr Skoda {@link http://skodak.org} * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ /** * Class used for event dispatching. * * Note: Do NOT use directly in your code, it is intended to be used from * base event class only. */ class manager { /** @var array buffer of event for dispatching */ protected static $buffer = array(); /** @var array buffer for events that were not sent to external observers when DB transaction in progress */ protected static $extbuffer = array(); /** @var bool evert dispatching already in progress - prevents nesting */ protected static $dispatching = false; /** @var array cache of all observers */ protected static $allobservers = null; /** @var bool should we reload observers after the test? */ protected static $reloadaftertest = false; /** * Trigger new event. * * @internal to be used only from \core\event\base::trigger() method. * @param \core\event\base $event * * @throws \coding_Exception if used directly. */ public static function dispatch(\core\event\base $event) { if (during_initial_install()) { return; } if (!$event->is_triggered() or $event->is_dispatched()) { throw new \coding_exception('Illegal event dispatching attempted.'); } self::$buffer[] = $event; if (self::$dispatching) { return; } self::$dispatching = true; self::process_buffers(); self::$dispatching = false; } /** * Notification from DML layer. * @internal to be used from DML layer only. */ public static function database_transaction_commited() { if (self::$dispatching or empty(self::$extbuffer)) { return; } self::$dispatching = true; self::process_buffers(); self::$dispatching = false; } /** * Notification from DML layer. * @internal to be used from DML layer only. */ public static function database_transaction_rolledback() { self::$extbuffer = array(); } protected static function process_buffers() { global $DB, $CFG; self::init_all_observers(); while (self::$buffer or self::$extbuffer) { $fromextbuffer = false; $addedtoextbuffer = false; if (self::$extbuffer and !$DB->is_transaction_started()) { $fromextbuffer = true; $event = reset(self::$extbuffer); unset(self::$extbuffer[key(self::$extbuffer)]); } else if (self::$buffer) { $event = reset(self::$buffer); unset(self::$buffer[key(self::$buffer)]); } else { return; } $observingclasses = self::get_observing_classes($event); foreach ($observingclasses as $observingclass) { if (!isset(self::$allobservers[$observingclass])) { continue; } foreach (self::$allobservers[$observingclass] as $observer) { if ($observer->internal) { if ($fromextbuffer) { // Do not send buffered external events to internal handlers, // they processed them already. continue; } } else { if ($DB->is_transaction_started()) { if ($fromextbuffer) { // Weird! continue; } // Do not notify external observers while in DB transaction. if (!$addedtoextbuffer) { self::$extbuffer[] = $event; $addedtoextbuffer = true; } continue; } } if (isset($observer->includefile) and file_exists($observer->includefile)) { include_once($observer->includefile); } if (is_callable($observer->callable)) { try { call_user_func($observer->callable, $event); } catch (\Exception $e) { // Observers are notified before installation and upgrade, this may throw errors. if (empty($CFG->upgraderunning)) { // Ignore errors during upgrade, otherwise warn developers. debugging("Exception encountered in event observer '$observer->callable': ".$e->getMessage(), DEBUG_DEVELOPER, $e->getTrace()); } } } else { debugging("Can not execute event observer '$observer->callable'"); } } } // TODO: Invent some infinite loop protection in case events cross-trigger one another. } } /** * Returns list of classes related to this event. * @param \core\event\base $event * @return array */ protected static function get_observing_classes(\core\event\base $event) { $classname = get_class($event); $observers = array('\\'.$classname); while ($classname = get_parent_class($classname)) { $observers[] = '\\'.$classname; } $observers = array_reverse($observers, false); return $observers; } /** * Initialise the list of observers. */ protected static function init_all_observers() { global $CFG; if (is_array(self::$allobservers)) { return; } if (!PHPUNIT_TEST and !during_initial_install()) { $cache = \cache::make('core', 'observers'); $cached = $cache->get('all'); $dirroot = $cache->get('dirroot'); if ($dirroot === $CFG->dirroot and is_array($cached)) { self::$allobservers = $cached; return; } } self::$allobservers = array(); $plugintypes = \core_component::get_plugin_types(); $plugintypes = array_merge(array('core' => 'not used'), $plugintypes); $systemdone = false; foreach ($plugintypes as $plugintype => $ignored) { if ($plugintype === 'core') { $plugins['core'] = "$CFG->dirroot/lib"; } else { $plugins = \core_component::get_plugin_list($plugintype); } foreach ($plugins as $plugin => $fulldir) { if (!file_exists("$fulldir/db/events.php")) { continue; } $observers = null; include("$fulldir/db/events.php"); if (!is_array($observers)) { continue; } self::add_observers($observers, "$fulldir/db/events.php", $plugintype, $plugin); } } self::order_all_observers(); if (!PHPUNIT_TEST and !during_initial_install()) { $cache->set('all', self::$allobservers); $cache->set('dirroot', $CFG->dirroot); } } /** * Add observers. * @param array $observers * @param string $file * @param string $plugintype Plugin type of the observer. * @param string $plugin Plugin of the observer. */ protected static function add_observers(array $observers, $file, $plugintype = null, $plugin = null) { global $CFG; foreach ($observers as $observer) { if (empty($observer['eventname']) or !is_string($observer['eventname'])) { debugging("Invalid 'eventname' detected in $file observer definition", DEBUG_DEVELOPER); continue; } if ($observer['eventname'] === '*') { $observer['eventname'] = '\core\event\base'; } if (strpos($observer['eventname'], '\\') !== 0) { $observer['eventname'] = '\\'.$observer['eventname']; } if (empty($observer['callback'])) { debugging("Invalid 'callback' detected in $file observer definition", DEBUG_DEVELOPER); continue; } $o = new \stdClass(); $o->callable = $observer['callback']; if (!isset($observer['priority'])) { $o->priority = 0; } else { $o->priority = (int)$observer['priority']; } if (!isset($observer['internal'])) { $o->internal = true; } else { $o->internal = (bool)$observer['internal']; } if (empty($observer['includefile'])) { $o->includefile = null; } else { if ($CFG->admin !== 'admin' and strpos($observer['includefile'], '/admin/') === 0) { $observer['includefile'] = preg_replace('|^/admin/|', '/'.$CFG->admin.'/', $observer['includefile']); } $observer['includefile'] = $CFG->dirroot . '/' . ltrim($observer['includefile'], '/'); if (!file_exists($observer['includefile'])) { debugging("Invalid 'includefile' detected in $file observer definition", DEBUG_DEVELOPER); continue; } $o->includefile = $observer['includefile']; } $o->plugintype = $plugintype; $o->plugin = $plugin; self::$allobservers[$observer['eventname']][] = $o; } } /** * Reorder observers to allow quick lookup of observer for each event. */ protected static function order_all_observers() { foreach (self::$allobservers as $classname => $observers) { \core_collator::asort_objects_by_property($observers, 'priority', \core_collator::SORT_NUMERIC); self::$allobservers[$classname] = array_reverse($observers); } } /** * Returns all observers in the system. This is only for use for reporting on the list of observers in the system. * * @access private * @return array An array of stdClass with all core observer details. */ public static function get_all_observers() { self::init_all_observers(); return self::$allobservers; } /** * Replace all standard observers. * @param array $observers * @return array * * @throws \coding_Exception if used outside of unit tests. */ public static function phpunit_replace_observers(array $observers) { if (!PHPUNIT_TEST) { throw new \coding_exception('Cannot override event observers outside of phpunit tests!'); } self::phpunit_reset(); self::$allobservers = array(); self::$reloadaftertest = true; self::add_observers($observers, 'phpunit'); self::order_all_observers(); return self::$allobservers; } /** * Reset everything if necessary. * @private * * @throws \coding_Exception if used outside of unit tests. */ public static function phpunit_reset() { if (!PHPUNIT_TEST) { throw new \coding_exception('Cannot reset event manager outside of phpunit tests!'); } self::$buffer = array(); self::$extbuffer = array(); self::$dispatching = false; if (!self::$reloadaftertest) { self::$allobservers = null; } self::$reloadaftertest = false; } }