mirror of
https://github.com/moodle/moodle.git
synced 2025-01-19 14:27:22 +01:00
484 lines
17 KiB
PHP
Executable File
484 lines
17 KiB
PHP
Executable File
<?php
|
|
/**
|
|
* Library of functions for events manipulation.
|
|
*
|
|
* @author Martin Dougiamas and many others
|
|
* @version $Id$
|
|
* @license http://www.gnu.org/copyleft/gpl.html GNU Public License
|
|
* @package moodlecore
|
|
*/
|
|
|
|
|
|
/**
|
|
* Loads the events definitions for the component (from file). If no
|
|
* events are defined for the component, we simply return an empty array.
|
|
* @param $component - examples: 'moodle', 'mod/forum', 'block/quiz_results'
|
|
* @return array of capabilities or empty array if not exists
|
|
*
|
|
* INTERNAL - to be used from eventslib only
|
|
*/
|
|
function events_load_def($component) {
|
|
global $CFG;
|
|
|
|
if ($component == 'moodle') {
|
|
$defpath = $CFG->libdir.'/db/events.php';
|
|
|
|
} else if ($component == 'unittest') {
|
|
$defpath = $CFG->libdir.'/simpletest/fixtures/events.php';
|
|
|
|
} else {
|
|
$compparts = explode('/', $component);
|
|
|
|
if ($compparts[0] == 'block') {
|
|
// Blocks are an exception. Blocks directory is 'blocks', and not
|
|
// 'block'. So we need to jump through hoops.
|
|
$defpath = $CFG->dirroot.'/blocks/'.$compparts[1].'/db/events.php';
|
|
|
|
} else if ($compparts[0] == 'format') {
|
|
// Similar to the above, course formats are 'format' while they
|
|
// are stored in 'course/format'.
|
|
$defpath = $CFG->dirroot.'/course/format/'.$compparts[1].'/db/events.php';
|
|
|
|
} else if ($compparts[0] == 'gradeimport') {
|
|
$defpath = $CFG->dirroot.'/grade/import/'.$compparts[1].'/db/events.php';
|
|
|
|
} else if ($compparts[0] == 'gradeexport') {
|
|
$defpath = $CFG->dirroot.'/grade/export/'.$compparts[1].'/db/events.php';
|
|
|
|
} else if ($compparts[0] == 'gradereport') {
|
|
$defpath = $CFG->dirroot.'/grade/report/'.$compparts[1].'/db/events.php';
|
|
|
|
} else {
|
|
$defpath = $CFG->dirroot.'/'.$component.'/db/events.php';
|
|
}
|
|
}
|
|
|
|
$events = array(); // TODO: $handlers might be better here ;-)
|
|
|
|
if (file_exists($defpath)) {
|
|
require($defpath);
|
|
}
|
|
|
|
return $events;
|
|
}
|
|
|
|
/**
|
|
* Gets the capabilities that have been cached in the database for this
|
|
* component.
|
|
* @param $component - examples: 'moodle', 'mod/forum', 'block/quiz_results'
|
|
* @return array of events
|
|
*
|
|
* INTERNAL - to be used from eventslib only
|
|
*/
|
|
function events_get_cached($component) {
|
|
$cachedhandlers = array();
|
|
|
|
if ($storedhandlers = get_records('events_handlers', 'handlermodule', $component)) {
|
|
foreach ($storedhandlers as $handler) {
|
|
$cachedhandlers[$handler->eventname] = array (
|
|
'id' => $handler->id,
|
|
'handlerfile' => $handler->handlerfile,
|
|
'handlerfunction' => $handler->handlerfunction,
|
|
'schedule' => $handler->schedule);
|
|
}
|
|
}
|
|
|
|
return $cachedhandlers;
|
|
}
|
|
|
|
/**
|
|
* We can not removed all event handlers in table, then add them again
|
|
* because event handlers could be referenced by queued items
|
|
*
|
|
* Note that the absence of the db/events.php event definition file
|
|
* will cause any queued events for the component to be removed from
|
|
* the database.
|
|
*
|
|
* @param $component - examples: 'moodle', 'mod/forum', 'block/quiz_results'
|
|
* @return boolean
|
|
*/
|
|
function events_update_definition($component='moodle') {
|
|
|
|
// load event definition from events.php
|
|
$filehandlers = events_load_def($component);
|
|
|
|
// load event definitions from db tables
|
|
// if we detect an event being already stored, we discard from this array later
|
|
// the remaining needs to be removed
|
|
$cachedhandlers = events_get_cached($component);
|
|
|
|
foreach ($filehandlers as $eventname => $filehandler) {
|
|
if (!empty($cachedhandlers[$eventname])) {
|
|
if ($cachedhandlers[$eventname]['handlerfile'] == $filehandler['handlerfile'] &&
|
|
$cachedhandlers[$eventname]['handlerfunction'] == serialize($filehandler['handlerfunction']) &&
|
|
$cachedhandlers[$eventname]['schedule'] == $filehandler['schedule']) {
|
|
// exact same event handler already present in db, ignore this entry
|
|
|
|
unset($cachedhandlers[$eventname]);
|
|
continue;
|
|
|
|
} else {
|
|
// same event name matches, this event has been updated, update the datebase
|
|
$handler = new object();
|
|
$handler->id = $cachedhandlers[$eventname]['id'];
|
|
$handler->handlerfile = $filehandler['handlerfile'];
|
|
$handler->handlerfunction = serialize($filehandler['handlerfunction']); // static class methods stored as array
|
|
$handler->schedule = $filehandler['schedule'];
|
|
|
|
update_record('events_handlers', $handler);
|
|
|
|
unset($cachedhandlers[$eventname]);
|
|
continue;
|
|
}
|
|
|
|
} else {
|
|
// if we are here, this event handler is not present in db (new)
|
|
// add it
|
|
$handler = new object();
|
|
$handler->eventname = $eventname;
|
|
$handler->handlermodule = $component;
|
|
$handler->handlerfile = $filehandler['handlerfile'];
|
|
$handler->handlerfunction = serialize($filehandler['handlerfunction']); // static class methods stored as array
|
|
$handler->schedule = $filehandler['schedule'];
|
|
|
|
insert_record('events_handlers', $handler);
|
|
}
|
|
}
|
|
|
|
// clean up the left overs, the entries in cachedevents array at this points are deprecated event handlers
|
|
// and should be removed, delete from db
|
|
events_cleanup($component, $cachedhandlers);
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Remove all event handlers and queued events
|
|
* @param $component - examples: 'moodle', 'mod/forum', 'block/quiz_results'
|
|
*/
|
|
function events_uninstall($component) {
|
|
$cachedhandlers = events_get_cached($component);
|
|
events_cleanup($component, $cachedhandlers);
|
|
}
|
|
|
|
/**
|
|
* Deletes cached events that are no longer needed by the component.
|
|
* @param $component - examples: 'moodle', 'mod/forum', 'block/quiz_results'
|
|
* @param $chachedevents - array of the cached events definitions that will be
|
|
* @return int - number of deprecated capabilities that have been removed
|
|
*
|
|
* INTERNAL - to be used from eventslib only
|
|
*/
|
|
function events_cleanup($component, $cachedhandlers) {
|
|
$deletecount = 0;
|
|
foreach ($cachedhandlers as $eventname => $cachedhandler) {
|
|
if ($qhandlers = get_records('events_queue_handlers', 'handlerid', $cachedhandler['id'])) {
|
|
debugging("Removing pending events from queue before deleting of event handler: $component - $eventname");
|
|
foreach ($qhandlers as $qhandler) {
|
|
events_dequeue($qhandler);
|
|
}
|
|
}
|
|
if (delete_records('events_handlers', 'eventname', $eventname, 'handlermodule', $component)) {
|
|
$deletecount++;
|
|
}
|
|
}
|
|
return $deletecount;
|
|
}
|
|
|
|
/****************** End of Events handler Definition code *******************/
|
|
|
|
/**
|
|
* puts a handler on queue
|
|
* @param object handler - event handler object from db
|
|
* @param object eventdata - event data object
|
|
* @return id number of new queue handler
|
|
*
|
|
* INTERNAL - to be used from eventslib only
|
|
*/
|
|
function events_queue_handler($handler, $event, $errormessage) {
|
|
|
|
if ($qhandler = get_record('events_queue_handlers', 'queuedeventid', $event->id, 'handlerid', $handler->id)) {
|
|
debugging("Please check code: Event id $event->id is already queued in handler id $qhandler->id");
|
|
return $qhandler->id;
|
|
}
|
|
|
|
// make a new queue handler
|
|
$qhandler = new object();
|
|
$qhandler->queuedeventid = $event->id;
|
|
$qhandler->handlerid = $handler->id;
|
|
$qhandler->errormessage = addslashes($errormessage);
|
|
$qhandler->timemodified = time();
|
|
if ($handler->schedule == 'instant' and $handler->status == 1) {
|
|
$qhandler->status = 1; //already one failed attempt to dispatch this event
|
|
} else {
|
|
$qhandler->status = 0;
|
|
}
|
|
|
|
return insert_record('events_queue_handlers', $qhandler);
|
|
}
|
|
|
|
/**
|
|
* trigger a single event with a specified handler
|
|
* @param handler - hander object from db
|
|
* @param eventdata - event dataobject
|
|
* @param errormessage - error message indicating problem
|
|
* @return bool - success or fail
|
|
*
|
|
* INTERNAL - to be used from eventslib only
|
|
*/
|
|
function events_dispatch($handler, $eventdata, &$errormessage) {
|
|
global $CFG;
|
|
|
|
$function = unserialize($handler->handlerfunction);
|
|
|
|
if (is_callable($function)) {
|
|
// oki, no need for includes
|
|
|
|
} else if (file_exists($CFG->dirroot.$handler->handlerfile)) {
|
|
include_once($CFG->dirroot.$handler->handlerfile);
|
|
|
|
} else {
|
|
$errormessage = "Handler file of component $handler->handlermodule: $handler->handlerfile can not be found!";
|
|
return false;
|
|
}
|
|
|
|
// checks for handler validity
|
|
if (is_callable($function)) {
|
|
return call_user_func($function, $eventdata);
|
|
|
|
} else {
|
|
$errormessage = "Handler function of component $handler->handlermodule: $handler->handlerfunction not callable function or class method!";
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* given a queued handler, call the respective event handler to process the event
|
|
* @param object qhandler - events_queued_handler object from db
|
|
* @return boolean meaning success, or NULL on fatal failure
|
|
*
|
|
* INTERNAL - to be used from eventslib only
|
|
*/
|
|
function events_process_queued_handler($qhandler) {
|
|
global $CFG;
|
|
|
|
// get handler
|
|
if (!$handler = get_record('events_handlers', 'id', $qhandler->handlerid)) {
|
|
debugging("Error processing queue handler $qhandler->id, missing handler id: $qhandler->handlerid");
|
|
//irrecoverable error, remove broken queue handler
|
|
events_dequeue($qhandler);
|
|
return NULL;
|
|
}
|
|
|
|
// get event object
|
|
if (!$event = get_record('events_queue', 'id', $qhandler->queuedeventid)) {
|
|
// can't proceed with no event object - might happen when two crons running at the same time
|
|
debugging("Error processing queue handler $qhandler->id, missing event id: $qhandler->queuedeventid");
|
|
//irrecoverable error, remove broken queue handler
|
|
events_dequeue($qhandler);
|
|
return NULL;
|
|
}
|
|
|
|
// call the function specified by the handler
|
|
$errormessage = 'Unknown error';
|
|
if (events_dispatch($handler, unserialize($event->eventdata), $errormessage)) {
|
|
//everything ok
|
|
events_dequeue($qhandler);
|
|
return true;
|
|
|
|
} else {
|
|
//dispatching failed
|
|
$qh = new object();
|
|
$qh->id = $qhandler->id;
|
|
$qh->errormessage = addslashes($errormessage);
|
|
$qh->timemodified = time();
|
|
$qh->status = $qhandler->status + 1;
|
|
update_record('events_queue_handlers', $qh);
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* removes this queued handler from the events_queued_handler table
|
|
* removes events_queue record from events_queue if no more references to this event object exists
|
|
* @param object qhandler - events_queued_handler object from db
|
|
*
|
|
* INTERNAL - to be used from eventslib only
|
|
*/
|
|
function events_dequeue($qhandler) {
|
|
// first delete the queue handler
|
|
delete_records('events_queue_handlers', 'id', $qhandler->id);
|
|
|
|
// if no more queued handler is pointing to the same event - delete the event too
|
|
if (!record_exists('events_queue_handlers', 'queuedeventid', $qhandler->queuedeventid)) {
|
|
delete_records('events_queue', 'id', $qhandler->queuedeventid);
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/****** Public events API starts here, do not use functions above in 3rd party code ******/
|
|
|
|
|
|
/**
|
|
* Events cron will try to empty the events queue by processing all the queued events handlers
|
|
* @param string eventname - empty means all
|
|
* @return number of dispatched+removed broken events
|
|
*
|
|
* PUBLIC
|
|
*/
|
|
function events_cron($eventname='') {
|
|
global $CFG;
|
|
|
|
$failed = array();
|
|
$processed = 0;
|
|
|
|
if ($eventname) {
|
|
$sql = "SELECT qh.* FROM {$CFG->prefix}events_queue_handlers qh, {$CFG->prefix}events_handlers h
|
|
WHERE qh.handlerid = h.id AND h.eventname='$eventname'
|
|
ORDER BY qh.id";
|
|
} else {
|
|
$sql = "SELECT * FROM {$CFG->prefix}events_queue_handlers
|
|
ORDER BY id";
|
|
}
|
|
|
|
if ($rs = get_recordset_sql($sql)) {
|
|
if ($rs->RecordCount() > 0) {
|
|
while ($qhandler = rs_fetch_next_record($rs)) {
|
|
if (in_array($qhandler->handlerid, $failed)) {
|
|
// do not try to dispatch any later events when one already failed
|
|
continue;
|
|
}
|
|
$status = events_process_queued_handler($qhandler);
|
|
if ($status === false) {
|
|
$failed[] = $qhandler->handlerid;
|
|
} else {
|
|
$processed++;
|
|
}
|
|
}
|
|
}
|
|
rs_close($rs);
|
|
}
|
|
return $processed;
|
|
}
|
|
|
|
|
|
/**
|
|
* Function to call all eventhandlers when triggering an event
|
|
* @param eventname - name of the event
|
|
* @param eventdata - event data object
|
|
* @return number of failed events
|
|
*
|
|
* PUBLIC
|
|
*/
|
|
function events_trigger($eventname, $eventdata) {
|
|
global $CFG, $USER;
|
|
|
|
$failedcount = 0; // number of failed events.
|
|
$event = false;
|
|
|
|
// pull out all registered event handlers
|
|
if ($handlers = get_records('events_handlers', 'eventname', $eventname)) {
|
|
foreach ($handlers as $handler) {
|
|
|
|
$errormessage = '';
|
|
|
|
if ($handler->schedule == 'instant') {
|
|
if ($handler->status) {
|
|
//check if previous pending events processed
|
|
if (!record_exists('events_queue_handlers', 'handlerid', $handler->id)) {
|
|
// ok, queue is empty, lets reset the status back to 0 == ok
|
|
$handler->status = 0;
|
|
set_field('events_handlers', 'status', 0, 'id', $handler->id);
|
|
}
|
|
}
|
|
|
|
// dispatch the event only if instant schedule and status ok
|
|
if (!$handler->status) {
|
|
$errormessage = 'Unknown error';;
|
|
if (events_dispatch($handler, $eventdata, $errormessage)) {
|
|
continue;
|
|
}
|
|
// set error count to 1 == send next instant into cron queue
|
|
set_field('events_handlers', 'status', 1, 'id', $handler->id);
|
|
|
|
} else {
|
|
// increment the error status counter
|
|
$handler->status++;
|
|
set_field('events_handlers', 'status', $handler->status, 'id', $handler->id);
|
|
}
|
|
|
|
// update the failed counter
|
|
$failedcount ++;
|
|
|
|
} else if ($handler->schedule == 'cron') {
|
|
//ok - use queuing of events only
|
|
|
|
} else {
|
|
// unknown schedule - fallback to cron type
|
|
debugging("Unknown handler schedule type: $handler->schedule");
|
|
}
|
|
|
|
// if even type is not instant, or dispatch failed, queue it
|
|
if ($event === false) {
|
|
$event = new object();
|
|
$event->userid = $USER->id;
|
|
$event->eventdata = serialize($eventdata);
|
|
$event->timecreated = time();
|
|
if (debugging()) {
|
|
$dump = '';
|
|
$callers = debug_backtrace();
|
|
foreach ($callers as $caller) {
|
|
$dump .= 'line ' . $caller['line'] . ' of ' . substr($caller['file'], strlen($CFG->dirroot) + 1);
|
|
if (isset($caller['function'])) {
|
|
$dump .= ': call to ';
|
|
if (isset($caller['class'])) {
|
|
$dump .= $caller['class'] . $caller['type'];
|
|
}
|
|
$dump .= $caller['function'] . '()';
|
|
}
|
|
$dump .= "\n";
|
|
}
|
|
$event->stackdump = addslashes($dump);
|
|
} else {
|
|
$event->stackdump = '';
|
|
}
|
|
$event->id = insert_record('events_queue', $event);
|
|
}
|
|
events_queue_handler($handler, $event, $errormessage);
|
|
}
|
|
} else {
|
|
debugging("No handler found for event: $eventname");
|
|
}
|
|
|
|
return $failedcount;
|
|
}
|
|
|
|
/**
|
|
* checks if an event is registered for this component
|
|
* @param string eventname - name of the event
|
|
* @param string component - component name, can be mod/data or moodle
|
|
* @return bool
|
|
*
|
|
* PUBLIC
|
|
*/
|
|
function events_is_registered($eventname, $component) {
|
|
return record_exists('events_handlers', 'handlermodule', $component, 'eventname', $eventname);
|
|
}
|
|
|
|
/**
|
|
* checks if an event is queued for processing - either cron handlers attached or failed instant handlers
|
|
* @param string eventname - name of the event
|
|
* @return int number of queued events
|
|
*
|
|
* PUBLIC
|
|
*/
|
|
function events_pending_count($eventname) {
|
|
global $CFG;
|
|
|
|
$sql = "SELECT COUNT(*) FROM {$CFG->prefix}events_queue_handlers qh, {$CFG->prefix}events_handlers h
|
|
WHERE qh.handlerid = h.id AND h.eventname='$eventname'";
|
|
return count_records_sql($sql);
|
|
}
|
|
?>
|