2 // This file is part of Moodle - http://moodle.org/
4 // Moodle is free software: you can redistribute it and/or modify
5 // it under the terms of the GNU General Public License as published by
6 // the Free Software Foundation, either version 3 of the License, or
7 // (at your option) any later version.
9 // Moodle is distributed in the hope that it will be useful,
10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 // GNU General Public License for more details.
14 // You should have received a copy of the GNU General Public License
15 // along with Moodle. If not, see <http://www.gnu.org/licenses/>.
19 defined('MOODLE_INTERNAL') ||
die();
22 * New event manager class.
26 * @copyright 2013 Petr Skoda {@link http://skodak.org}
27 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
31 * Class used for event dispatching.
33 * Note: Do NOT use directly in your code, it is intended to be used from
34 * base event class only.
37 /** @var array buffer of event for dispatching */
38 protected static $buffer = array();
40 /** @var array buffer for events that were not sent to external observers when DB transaction in progress */
41 protected static $extbuffer = array();
43 /** @var bool evert dispatching already in progress - prevents nesting */
44 protected static $dispatching = false;
46 /** @var array cache of all observers */
47 protected static $allobservers = null;
49 /** @var bool should we reload observers after the test? */
50 protected static $reloadaftertest = false;
55 * @internal to be used only from \core\event\base::trigger() method.
56 * @param \core\event\base $event
58 * @throws \coding_Exception if used directly.
60 public static function dispatch(\core\event\base
$event) {
61 if (during_initial_install()) {
64 if (!$event->is_triggered() or $event->is_dispatched()) {
65 throw new \
coding_exception('Illegal event dispatching attempted.');
68 self
::$buffer[] = $event;
70 if (self
::$dispatching) {
74 self
::$dispatching = true;
75 self
::process_buffers();
76 self
::$dispatching = false;
80 * Notification from DML layer.
81 * @internal to be used from DML layer only.
83 public static function database_transaction_commited() {
84 if (self
::$dispatching or empty(self
::$extbuffer)) {
88 self
::$dispatching = true;
89 self
::process_buffers();
90 self
::$dispatching = false;
94 * Notification from DML layer.
95 * @internal to be used from DML layer only.
97 public static function database_transaction_rolledback() {
98 self
::$extbuffer = array();
101 protected static function process_buffers() {
103 self
::init_all_observers();
105 while (self
::$buffer or self
::$extbuffer) {
107 $fromextbuffer = false;
108 $addedtoextbuffer = false;
110 if (self
::$extbuffer and !$DB->is_transaction_started()) {
111 $fromextbuffer = true;
112 $event = reset(self
::$extbuffer);
113 unset(self
::$extbuffer[key(self
::$extbuffer)]);
115 } else if (self
::$buffer) {
116 $event = reset(self
::$buffer);
117 unset(self
::$buffer[key(self
::$buffer)]);
123 $observingclasses = self
::get_observing_classes($event);
124 foreach ($observingclasses as $observingclass) {
125 if (!isset(self
::$allobservers[$observingclass])) {
128 foreach (self
::$allobservers[$observingclass] as $observer) {
129 if ($observer->internal
) {
130 if ($fromextbuffer) {
131 // Do not send buffered external events to internal handlers,
132 // they processed them already.
136 if ($DB->is_transaction_started()) {
137 if ($fromextbuffer) {
141 // Do not notify external observers while in DB transaction.
142 if (!$addedtoextbuffer) {
143 self
::$extbuffer[] = $event;
144 $addedtoextbuffer = true;
150 if (isset($observer->includefile
) and file_exists($observer->includefile
)) {
151 include_once($observer->includefile
);
153 if (is_callable($observer->callable
)) {
155 call_user_func($observer->callable
, $event);
156 } catch (\Exception
$e) {
157 // Observers are notified before installation and upgrade, this may throw errors.
158 if (empty($CFG->upgraderunning
)) {
159 // Ignore errors during upgrade, otherwise warn developers.
160 debugging("Exception encountered in event observer '$observer->callable': ".$e->getMessage(), DEBUG_DEVELOPER
, $e->getTrace());
164 debugging("Can not execute event observer '$observer->callable'");
169 // TODO: Invent some infinite loop protection in case events cross-trigger one another.
174 * Returns list of classes related to this event.
175 * @param \core\event\base $event
178 protected static function get_observing_classes(\core\event\base
$event) {
179 $classname = get_class($event);
180 $observers = array('\\'.$classname);
181 while ($classname = get_parent_class($classname)) {
182 $observers[] = '\\'.$classname;
184 $observers = array_reverse($observers, false);
190 * Initialise the list of observers.
192 protected static function init_all_observers() {
195 if (is_array(self
::$allobservers)) {
199 if (!PHPUNIT_TEST
and !during_initial_install()) {
200 $cache = \cache
::make('core', 'observers');
201 $cached = $cache->get('all');
202 $dirroot = $cache->get('dirroot');
203 if ($dirroot === $CFG->dirroot
and is_array($cached)) {
204 self
::$allobservers = $cached;
209 self
::$allobservers = array();
211 $plugintypes = \core_component
::get_plugin_types();
212 $plugintypes = array_merge(array('core' => 'not used'), $plugintypes);
214 foreach ($plugintypes as $plugintype => $ignored) {
215 if ($plugintype === 'core') {
216 $plugins['core'] = "$CFG->dirroot/lib";
218 $plugins = \core_component
::get_plugin_list($plugintype);
221 foreach ($plugins as $plugin => $fulldir) {
222 if (!file_exists("$fulldir/db/events.php")) {
226 include("$fulldir/db/events.php");
227 if (!is_array($observers)) {
230 self
::add_observers($observers, "$fulldir/db/events.php", $plugintype, $plugin);
234 self
::order_all_observers();
236 if (!PHPUNIT_TEST
and !during_initial_install()) {
237 $cache->set('all', self
::$allobservers);
238 $cache->set('dirroot', $CFG->dirroot
);
244 * @param array $observers
245 * @param string $file
246 * @param string $plugintype Plugin type of the observer.
247 * @param string $plugin Plugin of the observer.
249 protected static function add_observers(array $observers, $file, $plugintype = null, $plugin = null) {
252 foreach ($observers as $observer) {
253 if (empty($observer['eventname']) or !is_string($observer['eventname'])) {
254 debugging("Invalid 'eventname' detected in $file observer definition", DEBUG_DEVELOPER
);
257 if ($observer['eventname'] === '*') {
258 $observer['eventname'] = '\core\event\base';
260 if (strpos($observer['eventname'], '\\') !== 0) {
261 $observer['eventname'] = '\\'.$observer['eventname'];
263 if (empty($observer['callback'])) {
264 debugging("Invalid 'callback' detected in $file observer definition", DEBUG_DEVELOPER
);
267 $o = new \
stdClass();
268 $o->callable
= $observer['callback'];
269 if (!isset($observer['priority'])) {
272 $o->priority
= (int)$observer['priority'];
274 if (!isset($observer['internal'])) {
277 $o->internal
= (bool)$observer['internal'];
279 if (empty($observer['includefile'])) {
280 $o->includefile
= null;
282 if ($CFG->admin
!== 'admin' and strpos($observer['includefile'], '/admin/') === 0) {
283 $observer['includefile'] = preg_replace('|^/admin/|', '/'.$CFG->admin
.'/', $observer['includefile']);
285 $observer['includefile'] = $CFG->dirroot
. '/' . ltrim($observer['includefile'], '/');
286 if (!file_exists($observer['includefile'])) {
287 debugging("Invalid 'includefile' detected in $file observer definition", DEBUG_DEVELOPER
);
290 $o->includefile
= $observer['includefile'];
292 $o->plugintype
= $plugintype;
293 $o->plugin
= $plugin;
294 self
::$allobservers[$observer['eventname']][] = $o;
299 * Reorder observers to allow quick lookup of observer for each event.
301 protected static function order_all_observers() {
302 foreach (self
::$allobservers as $classname => $observers) {
303 \core_collator
::asort_objects_by_property($observers, 'priority', \core_collator
::SORT_NUMERIC
);
304 self
::$allobservers[$classname] = array_reverse($observers);
309 * Returns all observers in the system. This is only for use for reporting on the list of observers in the system.
312 * @return array An array of stdClass with all core observer details.
314 public static function get_all_observers() {
315 self
::init_all_observers();
316 return self
::$allobservers;
320 * Replace all standard observers.
321 * @param array $observers
324 * @throws \coding_Exception if used outside of unit tests.
326 public static function phpunit_replace_observers(array $observers) {
328 throw new \
coding_exception('Cannot override event observers outside of phpunit tests!');
331 self
::phpunit_reset();
332 self
::$allobservers = array();
333 self
::$reloadaftertest = true;
335 self
::add_observers($observers, 'phpunit');
336 self
::order_all_observers();
338 return self
::$allobservers;
342 * Reset everything if necessary.
345 * @throws \coding_Exception if used outside of unit tests.
347 public static function phpunit_reset() {
349 throw new \
coding_exception('Cannot reset event manager outside of phpunit tests!');
351 self
::$buffer = array();
352 self
::$extbuffer = array();
353 self
::$dispatching = false;
354 if (!self
::$reloadaftertest) {
355 self
::$allobservers = null;
357 self
::$reloadaftertest = false;