Your IP : 192.168.165.1
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle 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 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Observer class containing methods monitoring various events.
*
* @package tool_monitor
* @copyright 2014 onwards Ankit Agarwal <ankit.agrr@gmail.com>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
namespace tool_monitor;
defined('MOODLE_INTERNAL') || die();
/**
* Observer class containing methods monitoring various events.
*
* @since Moodle 2.8
* @package tool_monitor
* @copyright 2014 onwards Ankit Agarwal <ankit.agrr@gmail.com>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class eventobservers {
/** @var array $buffer buffer of events. */
protected $buffer = array();
/** @var int Number of entries in the buffer. */
protected $count = 0;
/** @var eventobservers a reference to a self instance. */
protected static $instance;
/**
* Course delete event observer.
* This observer monitors course delete event, and when a course is deleted it deletes any rules and subscriptions associated
* with it, so no orphan data is left behind.
*
* @param \core\event\course_deleted $event The course deleted event.
*/
public static function course_deleted(\core\event\course_deleted $event) {
// Delete rules defined inside this course and associated subscriptions.
$rules = rule_manager::get_rules_by_courseid($event->courseid, 0, 0, false);
foreach ($rules as $rule) {
rule_manager::delete_rule($rule->id, $event->get_context());
}
// Delete remaining subscriptions inside this course (from site-wide rules).
subscription_manager::remove_all_subscriptions_in_course($event->get_context());
}
/**
* The observer monitoring all the events.
*
* This observers puts small event objects in buffer for later writing to the database. At the end of the request the buffer
* is cleaned up and all data dumped into the tool_monitor_events table.
*
* @param \core\event\base $event event object
*/
public static function process_event(\core\event\base $event) {
if (!get_config('tool_monitor', 'enablemonitor')) {
return; // The tool is disabled. Nothing to do.
}
if (empty(self::$instance)) {
self::$instance = new static();
// Register shutdown handler - this is useful for buffering, processing events, etc.
\core_shutdown_manager::register_function(array(self::$instance, 'process_buffer'));
}
self::$instance->buffer_event($event);
if (PHPUNIT_TEST) {
// Process buffer after every event when unit testing.
self::$instance->process_buffer();
}
}
/**
* Api to buffer events to store, to reduce db queries.
*
* @param \core\event\base $event
*/
protected function buffer_event(\core\event\base $event) {
// If there are no subscriptions for this event do not buffer it.
if (!\tool_monitor\subscription_manager::event_has_subscriptions($event->eventname, $event->courseid)) {
return;
}
$eventdata = $event->get_data();
$eventobj = new \stdClass();
$eventobj->eventname = $eventdata['eventname'];
$eventobj->contextid = $eventdata['contextid'];
$eventobj->contextlevel = $eventdata['contextlevel'];
$eventobj->contextinstanceid = $eventdata['contextinstanceid'];
if ($event->get_url()) {
// Get link url if exists.
$eventobj->link = $event->get_url()->out();
} else {
$eventobj->link = '';
}
$eventobj->courseid = $eventdata['courseid'];
$eventobj->timecreated = $eventdata['timecreated'];
$this->buffer[] = $eventobj;
$this->count++;
}
/**
* This method process all events stored in the buffer.
*
* This is a multi purpose api. It does the following:-
* 1. Write event data to tool_monitor_events
* 2. Find out users that need to be notified about rule completion and schedule a task to send them messages.
*/
public function process_buffer() {
global $DB;
$events = $this->flush(); // Flush data.
$select = "SELECT COUNT(id) FROM {tool_monitor_events} ";
$now = time();
$messagestosend = array();
$allsubids = array();
// Let us now process the events and check for subscriptions.
foreach ($events as $eventobj) {
$subscriptions = subscription_manager::get_subscriptions_by_event($eventobj);
$idstosend = array();
foreach ($subscriptions as $subscription) {
// Only proceed to fire events and notifications if the subscription is active.
if (!subscription_manager::subscription_is_active($subscription)) {
continue;
}
$starttime = $now - $subscription->timewindow;
$starttime = ($starttime > $subscription->lastnotificationsent) ? $starttime : $subscription->lastnotificationsent;
if ($subscription->courseid == 0) {
// Site level subscription. Count all events.
$where = "eventname = :eventname AND timecreated > :starttime";
$params = array('eventname' => $eventobj->eventname, 'starttime' => $starttime);
} else {
// Course level subscription.
if ($subscription->cmid == 0) {
// All modules.
$where = "eventname = :eventname AND courseid = :courseid AND timecreated > :starttime";
$params = array('eventname' => $eventobj->eventname, 'courseid' => $eventobj->courseid,
'starttime' => $starttime);
} else {
// Specific module.
$where = "eventname = :eventname AND courseid = :courseid AND contextinstanceid = :cmid
AND timecreated > :starttime";
$params = array('eventname' => $eventobj->eventname, 'courseid' => $eventobj->courseid,
'cmid' => $eventobj->contextinstanceid, 'starttime' => $starttime);
}
}
$sql = $select . "WHERE " . $where;
$count = $DB->count_records_sql($sql, $params);
if (!empty($count) && $count >= $subscription->frequency) {
$idstosend[] = $subscription->id;
// Trigger a subscription_criteria_met event.
// It's possible that the course has been deleted since the criteria was met, so in that case use
// the system context. Set it here and change later if needed.
$context = \context_system::instance();
// We can't perform if (!empty($subscription->courseid)) below as it uses the magic method
// __get to return the variable, which will always result in being empty.
$courseid = $subscription->courseid;
if (!empty($courseid)) {
if ($coursecontext = \context_course::instance($courseid, IGNORE_MISSING)) {
$context = $coursecontext;
}
}
$params = array(
'userid' => $subscription->userid,
'courseid' => $subscription->courseid,
'context' => $context,
'other' => array(
'subscriptionid' => $subscription->id
)
);
$event = \tool_monitor\event\subscription_criteria_met::create($params);
$event->trigger();
}
}
if (!empty($idstosend)) {
$messagestosend[] = array('subscriptionids' => $idstosend, 'event' => $eventobj);
$allsubids = array_merge($allsubids, $idstosend);
}
}
if (!empty($allsubids)) {
// Update the last trigger flag.
list($sql, $params) = $DB->get_in_or_equal($allsubids, SQL_PARAMS_NAMED);
$params['now'] = $now;
$sql = "UPDATE {tool_monitor_subscriptions} SET lastnotificationsent = :now WHERE id $sql";
$DB->execute($sql, $params);
}
// Schedule a task to send notification.
if (!empty($messagestosend)) {
$adhocktask = new notification_task();
$adhocktask->set_custom_data($messagestosend);
$adhocktask->set_component('tool_monitor');
\core\task\manager::queue_adhoc_task($adhocktask);
}
}
/**
* Protected method that flushes the buffer of events and writes them to the database.
*
* @return array a copy of the events buffer.
*/
protected function flush() {
global $DB;
// Flush the buffer to the db.
$events = $this->buffer;
$DB->insert_records('tool_monitor_events', $events); // Insert the whole chunk into the database.
$this->buffer = array();
$this->count = 0;
return $events;
}
/**
* Observer that monitors user deleted event and delete user subscriptions.
*
* @param \core\event\user_deleted $event the event object.
*/
public static function user_deleted(\core\event\user_deleted $event) {
$userid = $event->objectid;
subscription_manager::delete_user_subscriptions($userid);
}
/**
* Observer that monitors course module deleted event and delete user subscriptions.
*
* @param \core\event\course_module_deleted $event the event object.
*/
public static function course_module_deleted(\core\event\course_module_deleted $event) {
$cmid = $event->contextinstanceid;
subscription_manager::delete_cm_subscriptions($cmid);
}
}