mirror of
https://github.com/moodle/moodle.git
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739 lines
23 KiB
PHP
739 lines
23 KiB
PHP
<?php
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// This file is part of Moodle - http://moodle.org/
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//
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// Moodle is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// Moodle is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
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/**
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* Moodle course analysable
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*
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* @package core_analytics
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* @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
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* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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*/
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namespace core_analytics;
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defined('MOODLE_INTERNAL') || die();
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require_once($CFG->dirroot . '/course/lib.php');
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require_once($CFG->dirroot . '/lib/gradelib.php');
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require_once($CFG->dirroot . '/lib/enrollib.php');
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/**
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* Moodle course analysable
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*
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* @package core_analytics
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* @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
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* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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*/
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class course implements \core_analytics\analysable {
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/**
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* @var \core_analytics\course[] $instances
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*/
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protected static $instances = array();
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/**
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* Course object
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*
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* @var \stdClass
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*/
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protected $course = null;
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/**
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* The course context.
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*
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* @var \context_course
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*/
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protected $coursecontext = null;
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/**
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* The course activities organized by activity type.
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*
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* @var array
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*/
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protected $courseactivities = array();
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/**
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* Course start time.
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*
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* @var int
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*/
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protected $starttime = null;
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/**
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* Has the course already started?
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*
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* @var bool
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*/
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protected $started = null;
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/**
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* Course end time.
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*
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* @var int
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*/
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protected $endtime = null;
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/**
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* Is the course finished?
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*
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* @var bool
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*/
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protected $finished = null;
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/**
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* Course students ids.
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*
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* @var int[]
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*/
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protected $studentids = [];
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/**
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* Course teachers ids
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*
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* @var int[]
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*/
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protected $teacherids = [];
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/**
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* Cached copy of the total number of logs in the course.
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*
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* @var int
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*/
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protected $ntotallogs = null;
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/**
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* Course manager constructor.
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*
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* Use self::instance() instead to get cached copies of the course. Instances obtained
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* through this constructor will not be cached.
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*
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* Loads course students and teachers.
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*
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* @param int|stdClass $course Course id
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* @return void
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*/
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public function __construct($course) {
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if (is_scalar($course)) {
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$this->course = get_course($course);
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} else {
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$this->course = $course;
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}
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$this->coursecontext = \context_course::instance($this->course->id);
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$this->now = time();
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// Get the course users, including users assigned to student and teacher roles at an higher context.
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$studentroles = array_keys(get_archetype_roles('student'));
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$this->studentids = $this->get_user_ids($studentroles);
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$teacherroles = array_keys(get_archetype_roles('editingteacher') + get_archetype_roles('teacher'));
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$this->teacherids = $this->get_user_ids($teacherroles);
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}
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/**
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* Returns an analytics course instance.
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*
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* @param int|stdClass $course Course id
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* @return \core_analytics\course
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*/
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public static function instance($course) {
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$courseid = $course;
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if (!is_scalar($courseid)) {
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$courseid = $course->id;
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}
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if (!empty(self::$instances[$courseid])) {
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return self::$instances[$courseid];
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}
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$instance = new \core_analytics\course($course);
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self::$instances[$courseid] = $instance;
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return self::$instances[$courseid];
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}
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/**
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* get_id
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*
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* @return int
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*/
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public function get_id() {
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return $this->course->id;
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}
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/**
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* get_context
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*
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* @return \context
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*/
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public function get_context() {
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if ($this->coursecontext === null) {
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$this->coursecontext = \context_course::instance($this->course->id);
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}
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return $this->coursecontext;
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}
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/**
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* Get the course start timestamp.
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*
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* @return int Timestamp or 0 if has not started yet.
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*/
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public function get_start() {
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if ($this->starttime !== null) {
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return $this->starttime;
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}
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// The field always exist but may have no valid if the course is created through a sync process.
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if (!empty($this->course->startdate)) {
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$this->starttime = (int)$this->course->startdate;
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} else {
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$this->starttime = 0;
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}
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return $this->starttime;
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}
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/**
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* Guesses the start of the course based on students' activity and enrolment start dates.
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*
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* @return int
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*/
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public function guess_start() {
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global $DB;
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if (!$this->get_total_logs()) {
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// Can't guess.
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return 0;
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}
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$logstore = \core_analytics\manager::get_analytics_logstore();
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// We first try to find current course student logs.
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$firstlogs = array();
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foreach ($this->studentids as $studentid) {
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// Grrr, we are limited by logging API, we could do this easily with a
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// select min(timecreated) from xx where courseid = yy group by userid.
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// Filters based on the premise that more than 90% of people will be using
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// standard logstore, which contains a userid, contextlevel, contextinstanceid index.
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$select = "userid = :userid AND contextlevel = :contextlevel AND contextinstanceid = :contextinstanceid";
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$params = array('userid' => $studentid, 'contextlevel' => CONTEXT_COURSE, 'contextinstanceid' => $this->get_id());
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$events = $logstore->get_events_select($select, $params, 'timecreated ASC', 0, 1);
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if ($events) {
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$event = reset($events);
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$firstlogs[] = $event->timecreated;
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}
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}
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if (empty($firstlogs)) {
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// Can't guess if no student accesses.
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return 0;
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}
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sort($firstlogs);
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$firstlogsmedian = $this->median($firstlogs);
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$studentenrolments = enrol_get_course_users($this->get_id(), $this->studentids);
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if (empty($studentenrolments)) {
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return 0;
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}
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$enrolstart = array();
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foreach ($studentenrolments as $studentenrolment) {
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$enrolstart[] = ($studentenrolment->uetimestart) ? $studentenrolment->uetimestart : $studentenrolment->uetimecreated;
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}
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sort($enrolstart);
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$enrolstartmedian = $this->median($enrolstart);
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return intval(($enrolstartmedian + $firstlogsmedian) / 2);
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}
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/**
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* Get the course end timestamp.
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*
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* @return int Timestamp or 0 if time end was not set.
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*/
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public function get_end() {
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global $DB;
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if ($this->endtime !== null) {
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return $this->endtime;
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}
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// The enddate field is only available from Moodle 3.2 (MDL-22078).
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if (!empty($this->course->enddate)) {
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$this->endtime = (int)$this->course->enddate;
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return $this->endtime;
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}
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return 0;
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}
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/**
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* Get the course end timestamp.
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*
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* @return int Timestamp, \core_analytics\analysable::MAX_TIME if we don't know but ongoing and 0 if we can not work it out.
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*/
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public function guess_end() {
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global $DB;
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if ($this->get_total_logs() === 0) {
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// No way to guess if there are no logs.
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$this->endtime = 0;
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return $this->endtime;
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}
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list($filterselect, $filterparams) = $this->course_students_query_filter('ula');
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// Consider the course open if there are still student accesses.
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$monthsago = time() - (WEEKSECS * 4 * 2);
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$select = $filterselect . ' AND timeaccess > :timeaccess';
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$params = $filterparams + array('timeaccess' => $monthsago);
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$sql = "SELECT timeaccess FROM {user_lastaccess} ula
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JOIN {enrol} e ON e.courseid = ula.courseid
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JOIN {user_enrolments} ue ON e.id = ue.enrolid AND ue.userid = ula.userid
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WHERE $select";
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if ($records = $DB->get_records_sql($sql, $params)) {
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return 0;
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}
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$sql = "SELECT timeaccess FROM {user_lastaccess} ula
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JOIN {enrol} e ON e.courseid = ula.courseid
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JOIN {user_enrolments} ue ON e.id = ue.enrolid AND ue.userid = ula.userid
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WHERE $filterselect AND ula.timeaccess != 0
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ORDER BY timeaccess DESC";
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$studentlastaccesses = $DB->get_fieldset_sql($sql, $filterparams);
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if (empty($studentlastaccesses)) {
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return 0;
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}
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sort($studentlastaccesses);
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return $this->median($studentlastaccesses);
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}
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/**
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* Returns a course plain object.
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*
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* @return \stdClass
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*/
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public function get_course_data() {
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return $this->course;
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}
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/**
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* Is the course valid to extract indicators from it?
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*
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* @return bool
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*/
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public function is_valid() {
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if (!$this->was_started() || !$this->is_finished()) {
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return false;
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}
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return true;
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}
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/**
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* Has the course started?
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*
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* @return bool
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*/
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public function was_started() {
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if ($this->started === null) {
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if ($this->get_start() === 0 || $this->now < $this->get_start()) {
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// Not yet started.
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$this->started = false;
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} else {
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$this->started = true;
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}
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}
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return $this->started;
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}
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/**
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* Has the course finished?
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*
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* @return bool
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*/
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public function is_finished() {
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if ($this->finished === null) {
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$endtime = $this->get_end();
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if ($endtime === 0 || $this->now < $endtime) {
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// It is not yet finished or no idea when it finishes.
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$this->finished = false;
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} else {
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$this->finished = true;
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}
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}
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return $this->finished;
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}
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/**
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* Returns a list of user ids matching the specified roles in this course.
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*
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* @param array $roleids
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* @return array
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*/
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public function get_user_ids($roleids) {
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// We need to index by ra.id as a user may have more than 1 $roles role.
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$records = get_role_users($roleids, $this->coursecontext, true, 'ra.id, u.id AS userid, r.id AS roleid', 'ra.id ASC');
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// If a user have more than 1 $roles role array_combine will discard the duplicate.
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$callable = array($this, 'filter_user_id');
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$userids = array_values(array_map($callable, $records));
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return array_combine($userids, $userids);
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}
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/**
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* Returns the course students.
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*
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* @return stdClass[]
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*/
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public function get_students() {
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return $this->studentids;
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}
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/**
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* Returns the total number of student logs in the course
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*
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* @return int
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*/
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public function get_total_logs() {
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global $DB;
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// No logs if no students.
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if (empty($this->studentids)) {
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return 0;
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}
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if ($this->ntotallogs === null) {
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list($filterselect, $filterparams) = $this->course_students_query_filter();
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$logstore = \core_analytics\manager::get_analytics_logstore();
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$this->ntotallogs = $logstore->get_events_select_count($filterselect, $filterparams);
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}
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return $this->ntotallogs;
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}
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/**
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* Returns all the activities of the provided type the course has.
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*
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* @param string $activitytype
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* @return array
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*/
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public function get_all_activities($activitytype) {
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// Using is set because we set it to false if there are no activities.
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if (!isset($this->courseactivities[$activitytype])) {
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$modinfo = get_fast_modinfo($this->get_course_data(), -1);
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$instances = $modinfo->get_instances_of($activitytype);
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if ($instances) {
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$this->courseactivities[$activitytype] = array();
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foreach ($instances as $instance) {
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// By context.
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$this->courseactivities[$activitytype][$instance->context->id] = $instance;
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}
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} else {
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$this->courseactivities[$activitytype] = false;
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}
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}
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return $this->courseactivities[$activitytype];
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}
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/**
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* Returns the course students grades.
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*
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* @param array $courseactivities
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* @return array
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*/
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public function get_student_grades($courseactivities) {
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if (empty($courseactivities)) {
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return array();
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}
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$grades = array();
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foreach ($courseactivities as $contextid => $instance) {
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$gradesinfo = grade_get_grades($this->course->id, 'mod', $instance->modname, $instance->instance, $this->studentids);
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// Sort them by activity context and user.
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if ($gradesinfo && $gradesinfo->items) {
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foreach ($gradesinfo->items as $gradeitem) {
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foreach ($gradeitem->grades as $userid => $grade) {
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if (empty($grades[$contextid][$userid])) {
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// Initialise it as array because a single activity can have multiple grade items (e.g. workshop).
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$grades[$contextid][$userid] = array();
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}
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$grades[$contextid][$userid][$gradeitem->id] = $grade;
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}
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}
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}
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}
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return $grades;
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}
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/**
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* Guesses all activities that were available during a period of time.
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*
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* @param string $activitytype
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* @param int $starttime
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* @param int $endtime
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* @param \stdClass $student
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* @return array
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*/
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public function get_activities($activitytype, $starttime, $endtime, $student = false) {
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// Var $student may not be available, default to not calculating dynamic data.
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$studentid = -1;
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if ($student) {
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$studentid = $student->id;
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}
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$modinfo = get_fast_modinfo($this->get_course_data(), $studentid);
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$activities = $modinfo->get_instances_of($activitytype);
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$timerangeactivities = array();
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foreach ($activities as $activity) {
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if (!$this->completed_by($activity, $starttime, $endtime)) {
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continue;
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}
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$timerangeactivities[$activity->context->id] = $activity;
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}
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return $timerangeactivities;
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}
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/**
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* Was the activity supposed to be completed during the provided time range?.
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*
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* @param \cm_info $activity
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* @param int $starttime
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* @param int $endtime
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* @return bool
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*/
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protected function completed_by(\cm_info $activity, $starttime, $endtime) {
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// We can't check uservisible because:
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// - Any activity with available until would not be counted.
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// - Sites may block student's course view capabilities once the course is closed.
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// Students can not view hidden activities by default, this is not reliable 100% but accurate in most of the cases.
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if ($activity->visible === false) {
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return false;
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}
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// We skip activities that were not yet visible or their 'until' was not in this $starttime - $endtime range.
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if ($activity->availability) {
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$info = new \core_availability\info_module($activity);
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$activityavailability = $this->availability_completed_by($info, $starttime, $endtime);
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if ($activityavailability === false) {
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return false;
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} else if ($activityavailability === true) {
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// This activity belongs to this time range.
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return true;
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}
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}
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// We skip activities in sections that were not yet visible or their 'until' was not in this $starttime - $endtime range.
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$section = $activity->get_modinfo()->get_section_info($activity->sectionnum);
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if ($section->availability) {
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$info = new \core_availability\info_section($section);
|
|
$sectionavailability = $this->availability_completed_by($info, $starttime, $endtime);
|
|
if ($sectionavailability === false) {
|
|
return false;
|
|
} else if ($sectionavailability === true) {
|
|
// This activity belongs to this section time range.
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// When the course is using format weeks we use the week's end date.
|
|
$format = course_get_format($activity->get_modinfo()->get_course());
|
|
if ($this->course->format === 'weeks') {
|
|
$dates = $format->get_section_dates($section);
|
|
|
|
// We need to consider the +2 hours added by get_section_dates.
|
|
// Avoid $starttime <= $dates->end because $starttime may be the start of the next week.
|
|
if ($starttime < ($dates->end - 7200) && $endtime >= ($dates->end - 7200)) {
|
|
return true;
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
if ($activity->sectionnum == 0) {
|
|
return false;
|
|
}
|
|
|
|
if (!$this->get_end() || !$this->get_start()) {
|
|
debugging('Activities which due date is in a time range can not be calculated ' .
|
|
'if the course doesn\'t have start and end date', DEBUG_DEVELOPER);
|
|
return false;
|
|
}
|
|
|
|
if (!course_format_uses_sections($this->course->format)) {
|
|
// If it does not use sections and there are no availability conditions to access it it is available
|
|
// and we can not magically classify it into any other time range than this one.
|
|
return true;
|
|
}
|
|
|
|
// Split the course duration in the number of sections and consider the end of each section the due
|
|
// date of all activities contained in that section.
|
|
$formatoptions = $format->get_format_options();
|
|
if (!empty($formatoptions['numsections'])) {
|
|
$nsections = $formatoptions['numsections'];
|
|
} else {
|
|
// There are course format that use sections but without numsections, we fallback to the number
|
|
// of cached sections in get_section_info_all, not that accurate though.
|
|
$coursesections = $activity->get_modinfo()->get_section_info_all();
|
|
$nsections = count($coursesections);
|
|
if (isset($coursesections[0])) {
|
|
// We don't count section 0 if it exists.
|
|
$nsections--;
|
|
}
|
|
}
|
|
|
|
$courseduration = $this->get_end() - $this->get_start();
|
|
$sectionduration = round($courseduration / $nsections);
|
|
$activitysectionenddate = $this->get_start() + ($sectionduration * $activity->sectionnum);
|
|
if ($activitysectionenddate > $starttime && $activitysectionenddate <= $endtime) {
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Check if the activity/section should have been completed during the provided period according to its availability rules.
|
|
*
|
|
* @param \core_availability\info $info
|
|
* @param int $starttime
|
|
* @param int $endtime
|
|
* @return bool|null
|
|
*/
|
|
protected function availability_completed_by(\core_availability\info $info, $starttime, $endtime) {
|
|
|
|
$dateconditions = $info->get_availability_tree()->get_all_children('\availability_date\condition');
|
|
foreach ($dateconditions as $condition) {
|
|
// Availability API does not allow us to check from / to dates nicely, we need to be naughty.
|
|
$conditiondata = $condition->save();
|
|
|
|
if ($conditiondata->d === \availability_date\condition::DIRECTION_FROM &&
|
|
$conditiondata->t > $endtime) {
|
|
// Skip this activity if any 'from' date is later than the end time.
|
|
return false;
|
|
|
|
} else if ($conditiondata->d === \availability_date\condition::DIRECTION_UNTIL &&
|
|
($conditiondata->t < $starttime || $conditiondata->t > $endtime)) {
|
|
// Skip activity if any 'until' date is not in $starttime - $endtime range.
|
|
return false;
|
|
} else if ($conditiondata->d === \availability_date\condition::DIRECTION_UNTIL &&
|
|
$conditiondata->t < $endtime && $conditiondata->t > $starttime) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// This can be interpreted as 'the activity was available but we don't know if its expected completion date
|
|
// was during this period.
|
|
return null;
|
|
}
|
|
|
|
/**
|
|
* Used by get_user_ids to extract the user id.
|
|
*
|
|
* @param \stdClass $record
|
|
* @return int The user id.
|
|
*/
|
|
protected function filter_user_id($record) {
|
|
return $record->userid;
|
|
}
|
|
|
|
/**
|
|
* Returns the average time between 2 timestamps.
|
|
*
|
|
* @param int $start
|
|
* @param int $end
|
|
* @return array [starttime, averagetime, endtime]
|
|
*/
|
|
protected function update_loop_times($start, $end) {
|
|
$avg = intval(($start + $end) / 2);
|
|
return array($start, $avg, $end);
|
|
}
|
|
|
|
/**
|
|
* Returns the query and params used to filter the logstore by this course students.
|
|
*
|
|
* @param string $prefix
|
|
* @return array
|
|
*/
|
|
protected function course_students_query_filter($prefix = false) {
|
|
global $DB;
|
|
|
|
if ($prefix) {
|
|
$prefix = $prefix . '.';
|
|
}
|
|
|
|
// Check the amount of student logs in the 4 previous weeks.
|
|
list($studentssql, $studentsparams) = $DB->get_in_or_equal($this->studentids, SQL_PARAMS_NAMED);
|
|
$filterselect = $prefix . 'courseid = :courseid AND ' . $prefix . 'userid ' . $studentssql;
|
|
$filterparams = array('courseid' => $this->course->id) + $studentsparams;
|
|
|
|
return array($filterselect, $filterparams);
|
|
}
|
|
|
|
/**
|
|
* Calculate median
|
|
*
|
|
* Keys are ignored.
|
|
*
|
|
* @param int|float $values Sorted array of values
|
|
* @return int
|
|
*/
|
|
protected function median($values) {
|
|
$count = count($values);
|
|
|
|
if ($count === 1) {
|
|
return reset($values);
|
|
}
|
|
|
|
$middlevalue = floor(($count - 1) / 2);
|
|
|
|
if ($count % 2) {
|
|
// Odd number, middle is the median.
|
|
$median = $values[$middlevalue];
|
|
} else {
|
|
// Even number, calculate avg of 2 medians.
|
|
$low = $values[$middlevalue];
|
|
$high = $values[$middlevalue + 1];
|
|
$median = (($low + $high) / 2);
|
|
}
|
|
return intval($median);
|
|
}
|
|
}
|