Proyectos de Subversion Moodle

<?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/>.

namespace core\event;

defined('MOODLE_INTERNAL') || die();

/**

 * Base event class.

 *

 * @package    core

 * @copyright  2013 Petr Skoda {@link http://skodak.org}

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

/**

 * All other event classes must extend this 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

 *

 * @property-read string $eventname Name of the event (=== class name with leading \)

 * @property-read string $component Full frankenstyle component name

 * @property-read string $action what happened

 * @property-read string $target what/who was target of the action

 * @property-read string $objecttable name of database table where is object record stored

 * @property-read int $objectid optional id of the object

 * @property-read string $crud letter indicating event type

 * @property-read int $edulevel log level (one of the constants LEVEL_)

 * @property-read int $contextid

 * @property-read int $contextlevel

 * @property-read int $contextinstanceid

 * @property-read int $userid who did this?

 * @property-read int $courseid the courseid of the event context, 0 for contexts above course

 * @property-read int $relateduserid

 * @property-read int $anonymous 1 means event should not be visible in reports, 0 means normal event,

 *                    create() argument may be also true/false.

 * @property-read mixed $other array or scalar, can not contain objects

 * @property-read int $timecreated

 */

abstract class base implements \IteratorAggregate {

    /**

     * Other level.

     */

    const LEVEL_OTHER = 0;

    /**

     * Teaching level.

     *

     * Any event that is performed by someone (typically a teacher) and has a teaching value,

     * anything that is affecting the learning experience/environment of the students.

     */

    const LEVEL_TEACHING = 1;

    /**

     * Participating level.

     *

     * Any event that is performed by a user, and is related (or could be related) to his learning experience.

     */

    const LEVEL_PARTICIPATING = 2;

    /**

     * The value used when an id can not be mapped during a restore.

     */

    const NOT_MAPPED = -31337;

    /**

     * The value used when an id can not be found during a restore.

     */

    const NOT_FOUND = -31338;

    /**

     * User id to use when the user is not logged in.

     */

    const USER_NOTLOGGEDIN = 0;

    /**

     * User id to use when actor is not an actual user but system, cli or cron.

     */

    const USER_OTHER = -1;

    /** @var array event data */

    protected $data;

    /** @var array the format is standardised by logging API */

    protected $logextra;

    /** @var \context of this event */

    protected $context;

    /**

     * @var bool indicates if event was already triggered,

     *           this prevents second attempt to trigger event.

     */

    private $triggered;

    /**

     * @var bool indicates if event was already dispatched,

     *           this prevents direct calling of manager::dispatch($event).

     */

    private $dispatched;

    /**

     * @var bool indicates if event was restored from storage,

     *           this prevents triggering of restored events.

     */

    private $restored;

    /** @var array list of event properties */

    private static $fields = array(

        'eventname', 'component', 'action', 'target', 'objecttable', 'objectid', 'crud', 'edulevel', 'contextid',

        'contextlevel', 'contextinstanceid', 'userid', 'courseid', 'relateduserid', 'anonymous', 'other',

        'timecreated');

    /** @var array simple record cache */

    private $recordsnapshots = array();

    /**

     * Private constructor, use create() or restore() methods instead.

     */

    final private function __construct() {

        $this->data = array_fill_keys(self::$fields, null);

        // Define some basic details.

        $classname = get_called_class();

        $parts = explode('\\', $classname);

        if (count($parts) !== 3 or $parts[1] !== 'event') {

            throw new \coding_exception("Invalid event class name '$classname', it must be defined in component\\event\\

                    namespace");

        }

        $this->data['eventname'] = '\\'.$classname;

        $this->data['component'] = $parts[0];

        $pos = strrpos($parts[2], '_');

        if ($pos === false) {

            throw new \coding_exception("Invalid event class name '$classname', there must be at least one underscore separating

                    object and action words");

        }

        $this->data['target'] = substr($parts[2], 0, $pos);

        $this->data['action'] = substr($parts[2], $pos + 1);

    }

    /**

     * Create new event.

     *

     * The optional data keys as:

     * 1/ objectid - the id of the object specified in class name

     * 2/ context - the context of this event

     * 3/ other - the other data describing the event, can not contain objects

     * 4/ relateduserid - the id of user which is somehow related to this event

     *

     * @param array $data

     * @return \core\event\base returns instance of new event

     *

     * @throws \coding_exception

     */

    final public static function create(array $data = null) {

        global $USER, $CFG;

        $data = (array)$data;

        /** @var \core\event\base $event */

        $event = new static();

        $event->triggered = false;

        $event->restored = false;

        $event->dispatched = false;

        // By default all events are visible in logs.

        $event->data['anonymous'] = 0;

        // Set static event data specific for child class.

        $event->init();

        if (isset($event->data['level'])) {

            if (!isset($event->data['edulevel'])) {

                debugging('level property is deprecated, use edulevel property instead', DEBUG_DEVELOPER);

                $event->data['edulevel'] = $event->data['level'];

            }

            unset($event->data['level']);

        }

        // Set automatic data.

        $event->data['timecreated'] = time();

        // Set optional data or use defaults.

        $event->data['objectid'] = isset($data['objectid']) ? $data['objectid'] : null;

        $event->data['courseid'] = isset($data['courseid']) ? $data['courseid'] : null;

        $event->data['userid'] = isset($data['userid']) ? $data['userid'] : $USER->id;

        $event->data['other'] = isset($data['other']) ? $data['other'] : null;

        $event->data['relateduserid'] = isset($data['relateduserid']) ? $data['relateduserid'] : null;

        if (isset($data['anonymous'])) {

            $event->data['anonymous'] = $data['anonymous'];

        }

        $event->data['anonymous'] = (int)(bool)$event->data['anonymous'];

        if (isset($event->context)) {

            if (isset($data['context'])) {

                debugging('Context was already set in init() method, ignoring context parameter', DEBUG_DEVELOPER);

            }

        } else if (!empty($data['context'])) {

            $event->context = $data['context'];

        } else if (!empty($data['contextid'])) {

            $event->context = \context::instance_by_id($data['contextid'], MUST_EXIST);

        } else {

            throw new \coding_exception('context (or contextid) is a required event property, system context may be hardcoded in init() method.');

        }

        $event->data['contextid'] = $event->context->id;

        $event->data['contextlevel'] = $event->context->contextlevel;

        $event->data['contextinstanceid'] = $event->context->instanceid;

        if (!isset($event->data['courseid'])) {

            if ($coursecontext = $event->context->get_course_context(false)) {

                $event->data['courseid'] = $coursecontext->instanceid;

            } else {

                $event->data['courseid'] = 0;

            }

        }

        if (!array_key_exists('relateduserid', $data) and $event->context->contextlevel == CONTEXT_USER) {

            $event->data['relateduserid'] = $event->context->instanceid;

        }

        // Warn developers if they do something wrong.

        if ($CFG->debugdeveloper) {

            static $automatickeys = array('eventname', 'component', 'action', 'target', 'contextlevel', 'contextinstanceid', 'timecreated');

            static $initkeys = array('crud', 'level', 'objecttable', 'edulevel');

            foreach ($data as $key => $ignored) {

                if ($key === 'context') {

                    continue;

                } else if (in_array($key, $automatickeys)) {

                    debugging("Data key '$key' is not allowed in \\core\\event\\base::create() method, it is set automatically", DEBUG_DEVELOPER);

                } else if (in_array($key, $initkeys)) {

                    debugging("Data key '$key' is not allowed in \\core\\event\\base::create() method, you need to set it in init() method", DEBUG_DEVELOPER);

                } else if (!in_array($key, self::$fields)) {

                    debugging("Data key '$key' does not exist in \\core\\event\\base");

                }

            }

            $expectedcourseid = 0;

            if ($coursecontext = $event->context->get_course_context(false)) {

                $expectedcourseid = $coursecontext->instanceid;

            }

            if ($expectedcourseid != $event->data['courseid']) {

                debugging("Inconsistent courseid - context combination detected.", DEBUG_DEVELOPER);

            }

            if (method_exists($event, 'get_legacy_logdata') ||

                method_exists($event, 'set_legacy_logdata') ||

                method_exists($event, 'get_legacy_eventname') ||

                method_exists($event, 'get_legacy_eventdata')

            ) {

                debugging("Invalid event functions defined in " . $event->data['eventname'], DEBUG_DEVELOPER);

            }

        }

        // Let developers validate their custom data (such as $this->data['other'], contextlevel, etc.).

        $event->validate_data();

        return $event;

    }

    /**

     * Override in subclass.

     *

     * Set all required data properties:

     *  1/ crud - letter [crud]

     *  2/ edulevel - using a constant self::LEVEL_*.

     *  3/ objecttable - name of database table if objectid specified

     *

     * Optionally it can set:

     * a/ fixed system context

     *

     * @return void

     */

    abstract protected function init();

    /**

     * Let developers validate their custom data (such as $this->data['other'], contextlevel, etc.).

     *

     * Throw \coding_exception or debugging() notice in case of any problems.

     */

    protected function validate_data() {

        // Override if you want to validate event properties when

        // creating new events.

    }

    /**

     * Returns localised general event name.

     *

     * Override in subclass, we can not make it static and abstract at the same time.

     *

     * @return string

     */

    public static function get_name() {

        // Override in subclass with real lang string.

        $parts = explode('\\', get_called_class());

        if (count($parts) !== 3) {

            return get_string('unknownevent', 'error');

        }

        return $parts[0].': '.str_replace('_', ' ', $parts[2]);

    }

    /**

     * Returns the event name complete with metadata information.

     *

     * This includes information about whether the event has been deprecated so should not be used in all situations -

     * for example within reports themselves.

     *

     * If overriding this function, please ensure that you call the parent version too.

     *

     * @return string

     */

    public static function get_name_with_info() {

        $return = static::get_name();

        if (static::is_deprecated()) {

            $return = get_string('deprecatedeventname', 'core', $return);

        }

        return $return;

    }

    /**

     * Returns non-localised event description with id's for admin use only.

     *

     * @return string

     */

    public function get_description() {

        return null;

    }

    /**

     * This method was originally intended for granular

     * access control on the event level, unfortunately

     * the proper implementation would be too expensive

     * in many cases.

     *

     * @deprecated since 2.7

     *

     * @param int|\stdClass $user_or_id ID of the user.

     * @return bool True if the user can view the event, false otherwise.

     */

    public function can_view($user_or_id = null) {

        debugging('can_view() method is deprecated, use anonymous flag instead if necessary.', DEBUG_DEVELOPER);

        return is_siteadmin($user_or_id);

    }

    /**

     * Restore event from existing historic data.

     *

     * @param array $data

     * @param array $logextra the format is standardised by logging API

     * @return bool|\core\event\base

     */

    final public static function restore(array $data, array $logextra) {

        $classname = $data['eventname'];

        $component = $data['component'];

        $action = $data['action'];

        $target = $data['target'];

        // Security: make 100% sure this really is an event class.

        if ($classname !== "\\{$component}\\event\\{$target}_{$action}") {

            return false;

        }

        if (!class_exists($classname)) {

            return self::restore_unknown($data, $logextra);

        }

        $event = new $classname();

        if (!($event instanceof \core\event\base)) {

            return false;

        }

        $event->init(); // Init method of events could be setting custom properties.

        $event->restored = true;

        $event->triggered = true;

        $event->dispatched = true;

        $event->logextra = $logextra;

        foreach (self::$fields as $key) {

            if (!array_key_exists($key, $data)) {

                debugging("Event restore data must contain key $key");

                $data[$key] = null;

            }

        }

        if (count($data) != count(self::$fields)) {

            foreach ($data as $key => $value) {

                if (!in_array($key, self::$fields)) {

                    debugging("Event restore data cannot contain key $key");

                    unset($data[$key]);

                }

            }

        }

        $event->data = $data;

        return $event;

    }

    /**

     * Restore unknown event.

     *

     * @param array $data

     * @param array $logextra

     * @return unknown_logged

     */

    final protected static function restore_unknown(array $data, array $logextra) {

        $classname = '\core\event\unknown_logged';

        /** @var unknown_logged $event */

        $event = new $classname();

        $event->restored = true;

        $event->triggered = true;

        $event->dispatched = true;

        $event->data = $data;

        $event->logextra = $logextra;

        return $event;

    }

    /**

     * Create fake event from legacy log data.

     *

     * @param \stdClass $legacy

     * @return base

     */

    final public static function restore_legacy($legacy) {

        $classname = get_called_class();

        /** @var base $event */

        $event = new $classname();

        $event->restored = true;

        $event->triggered = true;

        $event->dispatched = true;

        $context = false;

        $component = 'legacy';

        if ($legacy->cmid) {

            $context = \context_module::instance($legacy->cmid, IGNORE_MISSING);

            $component = 'mod_'.$legacy->module;

        } else if ($legacy->course) {

            $context = \context_course::instance($legacy->course, IGNORE_MISSING);

        }

        if (!$context) {

            $context = \context_system::instance();

        }

        $event->data = array();

        $event->data['eventname'] = $legacy->module.'_'.$legacy->action;

        $event->data['component'] = $component;

        $event->data['action'] = $legacy->action;

        $event->data['target'] = null;

        $event->data['objecttable'] = null;

        $event->data['objectid'] = null;

        if (strpos($legacy->action, 'view') !== false) {

            $event->data['crud'] = 'r';

        } else if (strpos($legacy->action, 'print') !== false) {

            $event->data['crud'] = 'r';

        } else if (strpos($legacy->action, 'update') !== false) {

            $event->data['crud'] = 'u';

        } else if (strpos($legacy->action, 'hide') !== false) {

            $event->data['crud'] = 'u';

        } else if (strpos($legacy->action, 'move') !== false) {

            $event->data['crud'] = 'u';

        } else if (strpos($legacy->action, 'write') !== false) {

            $event->data['crud'] = 'u';

        } else if (strpos($legacy->action, 'tag') !== false) {

            $event->data['crud'] = 'u';

        } else if (strpos($legacy->action, 'remove') !== false) {

            $event->data['crud'] = 'u';

        } else if (strpos($legacy->action, 'delete') !== false) {

            $event->data['crud'] = 'p';

        } else if (strpos($legacy->action, 'create') !== false) {

            $event->data['crud'] = 'c';

        } else if (strpos($legacy->action, 'post') !== false) {

            $event->data['crud'] = 'c';

        } else if (strpos($legacy->action, 'add') !== false) {

            $event->data['crud'] = 'c';

        } else {

            // End of guessing...

            $event->data['crud'] = 'r';

        }

        $event->data['edulevel'] = $event::LEVEL_OTHER;

        $event->data['contextid'] = $context->id;

        $event->data['contextlevel'] = $context->contextlevel;

        $event->data['contextinstanceid'] = $context->instanceid;

        $event->data['userid'] = ($legacy->userid ? $legacy->userid : null);

        $event->data['courseid'] = ($legacy->course ? $legacy->course : null);

        $event->data['relateduserid'] = ($legacy->userid ? $legacy->userid : null);

        $event->data['timecreated'] = $legacy->time;

        $event->logextra = array();

        if ($legacy->ip) {

            $event->logextra['origin'] = 'web';

            $event->logextra['ip'] = $legacy->ip;

        } else {

            $event->logextra['origin'] = 'cli';

            $event->logextra['ip'] = null;

        }

        $event->logextra['realuserid'] = null;

        $event->data['other'] = (array)$legacy;

        return $event;

    }

    /**

     * This is used when restoring course logs where it is required that we

     * map the objectid to it's new value in the new course.

     *

     * Does nothing in the base class except display a debugging message warning

     * the user that the event does not contain the required functionality to

     * map this information. For events that do not store an objectid this won't

     * be called, so no debugging message will be displayed.

     *

     * Example of usage:

     *

     * return array('db' => 'assign_submissions', 'restore' => 'submission');

     *

     * If the objectid can not be mapped during restore set the value to \core\event\base::NOT_MAPPED, example -

     *

     * return array('db' => 'some_table', 'restore' => \core\event\base::NOT_MAPPED);

     *

     * Note - it isn't necessary to specify the 'db' and 'restore' values in this case, so you can also use -

     *

     * return \core\event\base::NOT_MAPPED;

     *

     * The 'db' key refers to the database table and the 'restore' key refers to

     * the name of the restore element the objectid is associated with. In many

     * cases these will be the same.

     *

     * @return string the name of the restore mapping the objectid links to

     */

    public static function get_objectid_mapping() {

        debugging('In order to restore course logs accurately the event "' . get_called_class() . '" must define the

            function get_objectid_mapping().', DEBUG_DEVELOPER);

        return false;

    }

    /**

     * This is used when restoring course logs where it is required that we

     * map the information in 'other' to it's new value in the new course.

     *

     * Does nothing in the base class except display a debugging message warning

     * the user that the event does not contain the required functionality to

     * map this information. For events that do not store any other information this

     * won't be called, so no debugging message will be displayed.

     *

     * Example of usage:

     *

     * $othermapped = array();

     * $othermapped['discussionid'] = array('db' => 'forum_discussions', 'restore' => 'forum_discussion');

     * $othermapped['forumid'] = array('db' => 'forum', 'restore' => 'forum');

     * return $othermapped;

     *

     * If an id can not be mapped during restore we set it to \core\event\base::NOT_MAPPED, example -

     *

     * $othermapped = array();

     * $othermapped['someid'] = array('db' => 'some_table', 'restore' => \core\event\base::NOT_MAPPED);

     * return $othermapped;

     *

     * Note - it isn't necessary to specify the 'db' and 'restore' values in this case, so you can also use -

     *

     * $othermapped = array();

     * $othermapped['someid'] = \core\event\base::NOT_MAPPED;

     * return $othermapped;

     *

     * The 'db' key refers to the database table and the 'restore' key refers to

     * the name of the restore element the other value is associated with. In many

     * cases these will be the same.

     *

     * @return array an array of other values and their corresponding mapping

     */

    public static function get_other_mapping() {

        debugging('In order to restore course logs accurately the event "' . get_called_class() . '" must define the

            function get_other_mapping().', DEBUG_DEVELOPER);

    }

    /**

     * Get static information about an event.

     * This is used in reports and is not for general use.

     *

     * @return array Static information about the event.

     */

    final public static function get_static_info() {

        /** Var \core\event\base $event. */

        $event = new static();

        // Set static event data specific for child class.

        $event->init();

        return array(

            'eventname' => $event->data['eventname'],

            'component' => $event->data['component'],

            'target' => $event->data['target'],

            'action' => $event->data['action'],

            'crud' => $event->data['crud'],

            'edulevel' => $event->data['edulevel'],

            'objecttable' => $event->data['objecttable'],

        );

    }

    /**

     * Get an explanation of what the class does.

     * By default returns the phpdocs from the child event class. Ideally this should

     * be overridden to return a translatable get_string style markdown.

     * e.g. return new lang_string('eventyourspecialevent', 'plugin_type');

     *

     * @return string An explanation of the event formatted in markdown style.

     */

    public static function get_explanation() {

        $ref = new \ReflectionClass(get_called_class());

        $docblock = $ref->getDocComment();

        // Check that there is something to work on.

        if (empty($docblock)) {

            return null;

        }

        $docblocklines = explode("\n", $docblock);

        // Remove the bulk of the comment characters.

        $pattern = "/(^\s*\/\*\*|^\s+\*\s|^\s+\*)/";

        $cleanline = array();

        foreach ($docblocklines as $line) {

            $templine = preg_replace($pattern, '', $line);

            // If there is nothing on the line then don't add it to the array.

            if (!empty($templine)) {

                $cleanline[] = rtrim($templine);

            }

            // If we get to a line starting with an @ symbol then we don't want the rest.

            if (preg_match("/^@|\//", $templine)) {

                // Get rid of the last entry (it contains an @ symbol).

                array_pop($cleanline);

                // Break out of this foreach loop.

                break;

            }

        }

        // Add a line break to the sanitised lines.

        $explanation = implode("\n", $cleanline);

        return $explanation;

    }

    /**

     * Returns event context.

     * @return \context

     */

    public function get_context() {

        if (isset($this->context)) {

            return $this->context;

        }

        $this->context = \context::instance_by_id($this->data['contextid'], IGNORE_MISSING);

        return $this->context;

    }

    /**

     * Returns relevant URL, override in subclasses.

     * @return \moodle_url

     */

    public function get_url() {

        return null;

    }

    /**

     * Return standardised event data as array.

     *

     * @return array All elements are scalars except the 'other' field which is array.

     */

    public function get_data() {

        return $this->data;

    }

    /**

     * Return auxiliary data that was stored in logs.

     *

     * List of standard properties:

     *  - origin: IP number, cli,cron

     *  - realuserid: id of the user when logged-in-as

     *

     * @return array the format is standardised by logging API

     */

    public function get_logextra() {

        return $this->logextra;

    }

    /**

     * Validate all properties right before triggering the event.

     *

     * This throws coding exceptions for fatal problems and debugging for minor problems.

     *

     * @throws \coding_exception

     */

    protected function validate_before_trigger() {

        global $DB, $CFG;

        if (empty($this->data['crud'])) {

            throw new \coding_exception('crud must be specified in init() method of each method');

        }

        if (!isset($this->data['edulevel'])) {

            throw new \coding_exception('edulevel must be specified in init() method of each method');

        }

        if (!empty($this->data['objectid']) and empty($this->data['objecttable'])) {

            throw new \coding_exception('objecttable must be specified in init() method if objectid present');

        }

        if ($CFG->debugdeveloper) {

            // Ideally these should be coding exceptions, but we need to skip these for performance reasons

            // on production servers.

            if (!in_array($this->data['crud'], array('c', 'r', 'u', 'd'), true)) {

                debugging("Invalid event crud value specified.", DEBUG_DEVELOPER);

            }

            if (!in_array($this->data['edulevel'], array(self::LEVEL_OTHER, self::LEVEL_TEACHING, self::LEVEL_PARTICIPATING))) {

                // Bitwise combination of levels is not allowed at this stage.

                debugging('Event property edulevel must a constant value, see event_base::LEVEL_*', DEBUG_DEVELOPER);

            }

            if (self::$fields !== array_keys($this->data)) {

                debugging('Number of event data fields must not be changed in event classes', DEBUG_DEVELOPER);

            }

            $encoded = json_encode($this->data['other']);

            // The comparison here is not set to strict. We just need to check if the data is compatible with the JSON encoding

            // or not and we don't need to worry about how the data is encoded. Because in some cases, the data can contain

            // objects, and objects can be converted to a different format during encoding and decoding.

            if ($encoded === false) {

                debugging('other event data must be compatible with json encoding', DEBUG_DEVELOPER);

            }

            if ($this->data['userid'] and !is_number($this->data['userid'])) {

                debugging('Event property userid must be a number', DEBUG_DEVELOPER);

            }

            if ($this->data['courseid'] and !is_number($this->data['courseid'])) {

                debugging('Event property courseid must be a number', DEBUG_DEVELOPER);

            }

            if ($this->data['objectid'] and !is_number($this->data['objectid'])) {

                debugging('Event property objectid must be a number', DEBUG_DEVELOPER);

            }

            if ($this->data['relateduserid'] and !is_number($this->data['relateduserid'])) {

                debugging('Event property relateduserid must be a number', DEBUG_DEVELOPER);

            }

            if ($this->data['objecttable']) {

                if (!$DB->get_manager()->table_exists($this->data['objecttable'])) {

                    debugging('Unknown table specified in objecttable field', DEBUG_DEVELOPER);

                }

                if (!isset($this->data['objectid'])) {

                    debugging('Event property objectid must be set when objecttable is defined', DEBUG_DEVELOPER);

                }

            }

        }

    }

    /**

     * Trigger event.

     */

    final public function trigger() {

        global $CFG;

        if ($this->restored) {

            throw new \coding_exception('Can not trigger restored event');

        }

        if ($this->triggered or $this->dispatched) {

            throw new \coding_exception('Can not trigger event twice');

        }

        $this->validate_before_trigger();

        $this->triggered = true;

        if (PHPUNIT_TEST and \phpunit_util::is_redirecting_events()) {

            $this->dispatched = true;

            \phpunit_util::event_triggered($this);

            return;

        }

        \core\event\manager::dispatch($this);

        $this->dispatched = true;

    }

    /**

     * Was this event already triggered?

     *

     * @return bool

     */

    final public function is_triggered() {

        return $this->triggered;

    }

    /**

     * Used from event manager to prevent direct access.

     *

     * @return bool

     */

    final public function is_dispatched() {

        return $this->dispatched;

    }

    /**

     * Was this event restored?

     *

     * @return bool

     */

    final public function is_restored() {

        return $this->restored;

    }

    /**

     * Add cached data that will be most probably used in event observers.

     *

     * This is used to improve performance, but it is required for data

     * that was just deleted.

     *

     * @param string $tablename

     * @param \stdClass $record

     *

     * @throws \coding_exception if used after ::trigger()

     */

    final public function add_record_snapshot($tablename, $record) {

        global $DB, $CFG;

        if ($this->triggered) {

            throw new \coding_exception('It is not possible to add snapshots after triggering of events');

        }

        // Special case for course module, allow instance of cm_info to be passed instead of stdClass.

        if ($tablename === 'course_modules' && $record instanceof \cm_info) {

            $record = $record->get_course_module_record();

        }

        // NOTE: this might use some kind of MUC cache,

        //       hopefully we will not run out of memory here...

        if ($CFG->debugdeveloper) {

            if (!($record instanceof \stdClass)) {

                debugging('Argument $record must be an instance of stdClass.', DEBUG_DEVELOPER);

            }

            if (!$DB->get_manager()->table_exists($tablename)) {

                debugging("Invalid table name '$tablename' specified, database table does not exist.", DEBUG_DEVELOPER);

            } else {

                $columns = $DB->get_columns($tablename);

                $missingfields = array_diff(array_keys($columns), array_keys((array)$record));

                if (!empty($missingfields)) {

                    debugging("Fields list in snapshot record does not match fields list in '$tablename'. Record is missing fields: ".

                            join(', ', $missingfields), DEBUG_DEVELOPER);

                }

            }

        }

        $this->recordsnapshots[$tablename][$record->id] = $record;

    }

    /**

     * Returns cached record or fetches data from database if not cached.

     *

     * @param string $tablename

     * @param int $id

     * @return \stdClass

     *

     * @throws \coding_exception if used after ::restore()

     */

    final public function get_record_snapshot($tablename, $id) {

        global $DB;

        if ($this->restored) {

            throw new \coding_exception('It is not possible to get snapshots from restored events');

        }

        if (isset($this->recordsnapshots[$tablename][$id])) {

            return clone($this->recordsnapshots[$tablename][$id]);

        }

        $record = $DB->get_record($tablename, array('id'=>$id));

        $this->recordsnapshots[$tablename][$id] = $record;

        return $record;

    }

    /**

     * Magic getter for read only access.

     *

     * @param string $name

     * @return mixed

     */

    public function __get($name) {

        if ($name === 'level') {

            debugging('level property is deprecated, use edulevel property instead', DEBUG_DEVELOPER);

            return $this->data['edulevel'];

        }

        if (array_key_exists($name, $this->data)) {

            return $this->data[$name];

        }

        debugging("Accessing non-existent event property '$name'");

    }

    /**

     * Magic setter.

     *

     * Note: we must not allow modification of data from outside,

     *       after trigger() the data MUST NOT CHANGE!!!

     *

     * @param string $name

     * @param mixed $value

     *

     * @throws \coding_exception

     */

    public function __set($name, $value) {

        throw new \coding_exception('Event properties must not be modified.');

    }

    /**

     * Is data property set?

     *

     * @param string $name

     * @return bool

     */

    public function __isset($name) {

        if ($name === 'level') {

            debugging('level property is deprecated, use edulevel property instead', DEBUG_DEVELOPER);

            return isset($this->data['edulevel']);

        }

        return isset($this->data[$name]);

    }

    /**

     * Create an iterator because magic vars can't be seen by 'foreach'.

     *

     * @return \ArrayIterator

     */

    public function getIterator(): \Traversable {

        return new \ArrayIterator($this->data);

    }

    /**

     * Whether this event has been marked as deprecated.

     *

     * Events cannot be deprecated in the normal fashion as they must remain to support historical data.

     * Once they are deprecated, there is no way to trigger the event, so it does not make sense to list it in some

     * parts of the UI (e.g. Event Monitor).

     *

     * @return boolean

     */

    public static function is_deprecated() {

        return false;

    }

}