<?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/>.


< /**
<  * Back-end code for handling data about quizzes and the current user's attempt.
<  *
<  * There are classes for loading all the information about a quiz and attempts,
<  * and for displaying the navigation panel.
<  *
<  * @package   mod_quiz
<  * @copyright 2008 onwards Tim Hunt
<  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  */
< 
< 
< defined('MOODLE_INTERNAL') || die();
< 
< 
< /**
<  * Class for quiz exceptions. Just saves a couple of arguments on the
<  * constructor for a moodle_exception.
<  *
<  * @copyright 2008 Tim Hunt
<  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since     Moodle 2.0
<  */
< class moodle_quiz_exception extends moodle_exception {
<     /**
<      * Constructor.
<      *
<      * @param quiz $quizobj the quiz the error relates to.
<      * @param string $errorcode The name of the string from error.php to print.
<      * @param mixed $a Extra words and phrases that might be required in the error string.
<      * @param string $link The url where the user will be prompted to continue.
<      *      If no url is provided the user will be directed to the site index page.
<      * @param string|null $debuginfo optional debugging information.
<      */
<     public function __construct($quizobj, $errorcode, $a = null, $link = '', $debuginfo = null) {
<         if (!$link) {
<             $link = $quizobj->view_url();
<         }
<         parent::__construct($errorcode, 'quiz', $link, $a, $debuginfo);
<     }
< }
< 
< 
< /**
<  * A class encapsulating a quiz and the questions it contains, and making the
<  * information available to scripts like view.php.
<  *
<  * Initially, it only loads a minimal amout of information about each question - loading
<  * extra information only when necessary or when asked. The class tracks which questions
<  * are loaded.
<  *
<  * @copyright  2008 Tim Hunt
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since      Moodle 2.0
<  */
< class quiz {
<     /** @var stdClass the course settings from the database. */
<     protected $course;
<     /** @var stdClass the course_module settings from the database. */
<     protected $cm;
<     /** @var stdClass the quiz settings from the database. */
<     protected $quiz;
<     /** @var context the quiz context. */
<     protected $context;
< 
<     /** @var stdClass[] of questions augmented with slot information. */
<     protected $questions = null;
<     /** @var stdClass[] of quiz_section rows. */
<     protected $sections = null;
<     /** @var quiz_access_manager the access manager for this quiz. */
<     protected $accessmanager = null;
<     /** @var bool whether the current user has capability mod/quiz:preview. */
<     protected $ispreviewuser = null;
< 
<     // Constructor =============================================================
<     /**
<      * Constructor, assuming we already have the necessary data loaded.
<      *
<      * @param object $quiz the row from the quiz table.
<      * @param object $cm the course_module object for this quiz.
<      * @param object $course the row from the course table for the course we belong to.
<      * @param bool $getcontext intended for testing - stops the constructor getting the context.
<      */
<     public function __construct($quiz, $cm, $course, $getcontext = true) {
<         $this->quiz = $quiz;
<         $this->cm = $cm;
<         $this->quiz->cmid = $this->cm->id;
<         $this->course = $course;
<         if ($getcontext && !empty($cm->id)) {
<             $this->context = context_module::instance($cm->id);
<         }
<     }
< 
<     /**
<      * Static function to create a new quiz object for a specific user.
<      *
<      * @param int $quizid the the quiz id.
<      * @param int|null $userid the the userid (optional). If passed, relevant overrides are applied.
<      * @return quiz the new quiz object.
<      */
<     public static function create($quizid, $userid = null) {
<         global $DB;
< 
<         $quiz = quiz_access_manager::load_quiz_and_settings($quizid);
<         $course = $DB->get_record('course', array('id' => $quiz->course), '*', MUST_EXIST);
<         $cm = get_coursemodule_from_instance('quiz', $quiz->id, $course->id, false, MUST_EXIST);
< 
<         // Update quiz with override information.
<         if ($userid) {
<             $quiz = quiz_update_effective_access($quiz, $userid);
<         }
< 
<         return new quiz($quiz, $cm, $course);
<     }
< 
<     /**
<      * Create a {@link quiz_attempt} for an attempt at this quiz.
<      *
<      * @param object $attemptdata row from the quiz_attempts table.
<      * @return quiz_attempt the new quiz_attempt object.
<      */
<     public function create_attempt_object($attemptdata) {
<         return new quiz_attempt($attemptdata, $this->quiz, $this->cm, $this->course);
<     }
< 
<     // Functions for loading more data =========================================
< 
<     /**
<      * Load just basic information about all the questions in this quiz.
<      */
<     public function preload_questions() {
<         $this->questions = question_preload_questions(null,
<                 'slot.maxmark, slot.id AS slotid, slot.slot, slot.page,
<                  slot.questioncategoryid AS randomfromcategory,
<                  slot.includingsubcategories AS randomincludingsubcategories',
<                 '{quiz_slots} slot ON slot.quizid = :quizid AND q.id = slot.questionid',
<                 array('quizid' => $this->quiz->id), 'slot.slot');
<     }
< 
<     /**
<      * Fully load some or all of the questions for this quiz. You must call
<      * {@link preload_questions()} first.
<      *
<      * @param array|null $questionids question ids of the questions to load. null for all.
<      */
<     public function load_questions($questionids = null) {
<         if ($this->questions === null) {
<             throw new coding_exception('You must call preload_questions before calling load_questions.');
<         }
<         if (is_null($questionids)) {
<             $questionids = array_keys($this->questions);
<         }
<         $questionstoprocess = array();
<         foreach ($questionids as $id) {
<             if (array_key_exists($id, $this->questions)) {
<                 $questionstoprocess[$id] = $this->questions[$id];
<             }
<         }
<         get_question_options($questionstoprocess);
<     }
< 
<     /**
<      * Get an instance of the {@link \mod_quiz\structure} class for this quiz.
<      * @return \mod_quiz\structure describes the questions in the quiz.
<      */
<     public function get_structure() {
<         return \mod_quiz\structure::create_for_quiz($this);
<     }
< 
<     // Simple getters ==========================================================
<     /**
<      * Get the id of the course this quiz belongs to.
<      *
<      * @return int the course id.
<      */
<     public function get_courseid() {
<         return $this->course->id;
<     }
< 
<     /**
<      * Get the course settings object that this quiz belongs to.
<      *
<      * @return object the row of the course table.
<      */
<     public function get_course() {
<         return $this->course;
<     }
< 
<     /**
<      * Get this quiz's id (in the quiz table).
<      *
<      * @return int the quiz id.
<      */
<     public function get_quizid() {
<         return $this->quiz->id;
<     }
< 
<     /**
<      * Get the quiz settings object.
<      *
<      * @return stdClass the row of the quiz table.
<      */
<     public function get_quiz() {
<         return $this->quiz;
<     }
< 
<     /**
<      * Get the quiz name.
<      *
<      * @return string the name of this quiz.
<      */
<     public function get_quiz_name() {
<         return $this->quiz->name;
<     }
< 
<     /**
<      * Get the navigation method in use.
<      *
<      * @return int QUIZ_NAVMETHOD_FREE or QUIZ_NAVMETHOD_SEQ.
<      */
<     public function get_navigation_method() {
<         return $this->quiz->navmethod;
<     }
< 
<     /** @return int the number of attempts allowed at this quiz (0 = infinite). */
<     public function get_num_attempts_allowed() {
<         return $this->quiz->attempts;
<     }
< 
<     /**
<      * Get the course-module id for this quiz.
<      *
<      * @return int the course_module id.
<      */
<     public function get_cmid() {
<         return $this->cm->id;
<     }
< 
<     /**
<      * Get the course-module object for this quiz.
<      *
<      * @return object the course_module object.
<      */
<     public function get_cm() {
<         return $this->cm;
<     }
< 
<     /**
<      * Get the quiz context.
<      *
<      * @return context the module context for this quiz.
<      */
<     public function get_context() {
<         return $this->context;
<     }
< 
<     /**
<      * @return bool wether the current user is someone who previews the quiz,
<      * rather than attempting it.
<      */
<     public function is_preview_user() {
<         if (is_null($this->ispreviewuser)) {
<             $this->ispreviewuser = has_capability('mod/quiz:preview', $this->context);
<         }
<         return $this->ispreviewuser;
<     }
< 
<     /**
<      * Checks user enrollment in the current course.
<      *
<      * @param int $userid the id of the user to check.
<      * @return bool whether the user is enrolled.
<      */
<     public function is_participant($userid) {
<         return is_enrolled($this->get_context(), $userid, 'mod/quiz:attempt', $this->show_only_active_users());
<     }
< 
<     /**
<      * Check is only active users in course should be shown.
<      *
<      * @return bool true if only active users should be shown.
<      */
<     public function show_only_active_users() {
<         return !has_capability('moodle/course:viewsuspendedusers', $this->get_context());
<     }
< 
<     /**
<      * @return bool whether any questions have been added to this quiz.
<      */
<     public function has_questions() {
<         if ($this->questions === null) {
<             $this->preload_questions();
<         }
<         return !empty($this->questions);
<     }
< 
<     /**
<      * @param int $id the question id.
<      * @return stdClass the question object with that id.
<      */
<     public function get_question($id) {
<         return $this->questions[$id];
<     }
< 
<     /**
<      * @param array|null $questionids question ids of the questions to load. null for all.
<      * @return stdClass[] the question data objects.
<      */
<     public function get_questions($questionids = null) {
<         if (is_null($questionids)) {
<             $questionids = array_keys($this->questions);
<         }
<         $questions = array();
<         foreach ($questionids as $id) {
<             if (!array_key_exists($id, $this->questions)) {
<                 throw new moodle_exception('cannotstartmissingquestion', 'quiz', $this->view_url());
<             }
<             $questions[$id] = $this->questions[$id];
<             $this->ensure_question_loaded($id);
<         }
<         return $questions;
<     }
< 
<     /**
<      * Get all the sections in this quiz.
<      *
<      * @return array 0, 1, 2, ... => quiz_sections row from the database.
<      */
<     public function get_sections() {
<         global $DB;
<         if ($this->sections === null) {
<             $this->sections = array_values($DB->get_records('quiz_sections',
<                     array('quizid' => $this->get_quizid()), 'firstslot'));
<         }
<         return $this->sections;
<     }
< 
<     /**
<      * Return quiz_access_manager and instance of the quiz_access_manager class
<      * for this quiz at this time.
<      *
<      * @param int $timenow the current time as a unix timestamp.
<      * @return quiz_access_manager and instance of the quiz_access_manager class
<      *      for this quiz at this time.
<      */
<     public function get_access_manager($timenow) {
<         if (is_null($this->accessmanager)) {
<             $this->accessmanager = new quiz_access_manager($this, $timenow,
<                     has_capability('mod/quiz:ignoretimelimits', $this->context, null, false));
<         }
<         return $this->accessmanager;
<     }
< 
<     /**
<      * Wrapper round the has_capability funciton that automatically passes in the quiz context.
<      *
<      * @param string $capability the name of the capability to check. For example mod/quiz:view.
<      * @param int|null $userid A user id. By default (null) checks the permissions of the current user.
<      * @param bool $doanything If false, ignore effect of admin role assignment.
<      * @return boolean true if the user has this capability. Otherwise false.
<      */
<     public function has_capability($capability, $userid = null, $doanything = true) {
<         return has_capability($capability, $this->context, $userid, $doanything);
<     }
< 
<     /**
<      * Wrapper round the require_capability function that automatically passes in the quiz context.
<      *
<      * @param string $capability the name of the capability to check. For example mod/quiz:view.
<      * @param int|null $userid A user id. By default (null) checks the permissions of the current user.
<      * @param bool $doanything If false, ignore effect of admin role assignment.
<      */
<     public function require_capability($capability, $userid = null, $doanything = true) {
<         require_capability($capability, $this->context, $userid, $doanything);
<     }
< 
<     // URLs related to this attempt ============================================
<     /**
<      * @return string the URL of this quiz's view page.
<      */
<     public function view_url() {
<         global $CFG;
<         return $CFG->wwwroot . '/mod/quiz/view.php?id=' . $this->cm->id;
<     }
< 
<     /**
<      * @return string the URL of this quiz's edit page.
<      */
<     public function edit_url() {
<         global $CFG;
<         return $CFG->wwwroot . '/mod/quiz/edit.php?cmid=' . $this->cm->id;
<     }
< 
<     /**
<      * @param int $attemptid the id of an attempt.
<      * @param int $page optional page number to go to in the attempt.
<      * @return string the URL of that attempt.
<      */
<     public function attempt_url($attemptid, $page = 0) {
<         global $CFG;
<         $url = $CFG->wwwroot . '/mod/quiz/attempt.php?attempt=' . $attemptid;
<         if ($page) {
<             $url .= '&page=' . $page;
<         }
<         $url .= '&cmid=' . $this->get_cmid();
<         return $url;
<     }
< 
<     /**
<      * Get the URL to start/continue an attempt.
<      *
<      * @param int $page page in the attempt to start on (optional).
<      * @return moodle_url the URL of this quiz's edit page. Needs to be POSTed to with a cmid parameter.
<      */
<     public function start_attempt_url($page = 0) {
<         $params = array('cmid' => $this->cm->id, 'sesskey' => sesskey());
<         if ($page) {
<             $params['page'] = $page;
<         }
<         return new moodle_url('/mod/quiz/startattempt.php', $params);
<     }
< 
<     /**
<      * @param int $attemptid the id of an attempt.
<      * @return string the URL of the review of that attempt.
<      */
<     public function review_url($attemptid) {
<         return new moodle_url('/mod/quiz/review.php', array('attempt' => $attemptid, 'cmid' => $this->get_cmid()));
<     }
< 
<     /**
<      * @param int $attemptid the id of an attempt.
<      * @return string the URL of the review of that attempt.
<      */
<     public function summary_url($attemptid) {
<         return new moodle_url('/mod/quiz/summary.php', array('attempt' => $attemptid, 'cmid' => $this->get_cmid()));
<     }
< 
<     // Bits of content =========================================================
< 
<     /**
<      * @param bool $notused not used.
<      * @return string an empty string.
<      * @deprecated since 3.1. This sort of functionality is now entirely handled by quiz access rules.
<      */
<     public function confirm_start_attempt_message($notused) {
<         debugging('confirm_start_attempt_message is deprecated. ' .
<                 'This sort of functionality is now entirely handled by quiz access rules.');
<         return '';
<     }
< 
<     /**
<      * If $reviewoptions->attempt is false, meaning that students can't review this
<      * attempt at the moment, return an appropriate string explaining why.
<      *
<      * @param int $when One of the mod_quiz_display_options::DURING,
<      *      IMMEDIATELY_AFTER, LATER_WHILE_OPEN or AFTER_CLOSE constants.
<      * @param bool $short if true, return a shorter string.
<      * @return string an appropraite message.
<      */
<     public function cannot_review_message($when, $short = false) {
< 
<         if ($short) {
<             $langstrsuffix = 'short';
<             $dateformat = get_string('strftimedatetimeshort', 'langconfig');
<         } else {
<             $langstrsuffix = '';
<             $dateformat = '';
<         }
< 
<         if ($when == mod_quiz_display_options::DURING ||
<                 $when == mod_quiz_display_options::IMMEDIATELY_AFTER) {
<             return '';
<         } else if ($when == mod_quiz_display_options::LATER_WHILE_OPEN && $this->quiz->timeclose &&
<                 $this->quiz->reviewattempt & mod_quiz_display_options::AFTER_CLOSE) {
<             return get_string('noreviewuntil' . $langstrsuffix, 'quiz',
<                     userdate($this->quiz->timeclose, $dateformat));
<         } else {
<             return get_string('noreview' . $langstrsuffix, 'quiz');
<         }
<     }
< 
<     /**
<      * Probably not used any more, but left for backwards compatibility.
<      *
<      * @param string $title the name of this particular quiz page.
<      * @return string always returns ''.
<      */
<     public function navigation($title) {
<         global $PAGE;
<         $PAGE->navbar->add($title);
<         return '';
<     }
< 
<     // Private methods =========================================================
<     /**
<      * Check that the definition of a particular question is loaded, and if not throw an exception.
<      *
<      * @param int $id a question id.
<      */
<     protected function ensure_question_loaded($id) {
<         if (isset($this->questions[$id]->_partiallyloaded)) {
<             throw new moodle_quiz_exception($this, 'questionnotloaded', $id);
<         }
<     }
< 
<     /**
<      * Return all the question types used in this quiz.
<      *
<      * @param  boolean $includepotential if the quiz include random questions,
<      *      setting this flag to true will make the function to return all the
<      *      possible question types in the random questions category.
<      * @return array a sorted array including the different question types.
<      * @since  Moodle 3.1
<      */
<     public function get_all_question_types_used($includepotential = false) {
<         $questiontypes = array();
< 
<         // To control if we need to look in categories for questions.
<         $qcategories = array();
< 
<         // We must be careful with random questions, if we find a random question we must assume that the quiz may content
<         // any of the questions in the referenced category (or subcategories).
<         foreach ($this->get_questions() as $questiondata) {
<             if ($questiondata->qtype == 'random' and $includepotential) {
<                 $includesubcategories = (bool) $questiondata->questiontext;
<                 if (!isset($qcategories[$questiondata->category])) {
<                     $qcategories[$questiondata->category] = false;
<                 }
<                 if ($includesubcategories) {
<                     $qcategories[$questiondata->category] = true;
<                 }
<             } else {
<                 if (!in_array($questiondata->qtype, $questiontypes)) {
<                     $questiontypes[] = $questiondata->qtype;
<                 }
<             }
<         }
< 
<         if (!empty($qcategories)) {
<             // We have to look for all the question types in these categories.
<             $categoriestolook = array();
<             foreach ($qcategories as $cat => $includesubcats) {
<                 if ($includesubcats) {
<                     $categoriestolook = array_merge($categoriestolook, question_categorylist($cat));
<                 } else {
<                     $categoriestolook[] = $cat;
<                 }
<             }
<             $questiontypesincategories = question_bank::get_all_question_types_in_categories($categoriestolook);
<             $questiontypes = array_merge($questiontypes, $questiontypesincategories);
<         }
<         $questiontypes = array_unique($questiontypes);
<         sort($questiontypes);
< 
<         return $questiontypes;
<     }
< }
< 
< 
< /**
<  * This class extends the quiz class to hold data about the state of a particular attempt,
<  * in addition to the data about the quiz.
<  *
<  * @copyright  2008 Tim Hunt
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since      Moodle 2.0
<  */
< class quiz_attempt {
< 
<     /** @var string to identify the in progress state. */
<     const IN_PROGRESS = 'inprogress';
<     /** @var string to identify the overdue state. */
<     const OVERDUE     = 'overdue';
<     /** @var string to identify the finished state. */
<     const FINISHED    = 'finished';
<     /** @var string to identify the abandoned state. */
<     const ABANDONED   = 'abandoned';
< 
<     /** @var int maximum number of slots in the quiz for the review page to default to show all. */
<     const MAX_SLOTS_FOR_DEFAULT_REVIEW_SHOW_ALL = 50;
< 
<     /** @var quiz object containing the quiz settings. */
<     protected $quizobj;
< 
<     /** @var stdClass the quiz_attempts row. */
<     protected $attempt;
< 
<     /** @var question_usage_by_activity the question usage for this quiz attempt. */
<     protected $quba;
< 
<     /**
<      * @var array of slot information. These objects contain ->slot (int),
<      *      ->requireprevious (bool), ->questionids (int) the original question for random questions,
<      *      ->firstinsection (bool), ->section (stdClass from $this->sections).
<      *      This does not contain page - get that from {@link get_question_page()} -
<      *      or maxmark - get that from $this->quba.
<      */
<     protected $slots;
< 
<     /** @var array of quiz_sections rows, with a ->lastslot field added. */
<     protected $sections;
< 
<     /** @var array page no => array of slot numbers on the page in order. */
<     protected $pagelayout;
< 
<     /** @var array slot => displayed question number for this slot. (E.g. 1, 2, 3 or 'i'.) */
<     protected $questionnumbers;
< 
<     /** @var array slot => page number for this slot. */
<     protected $questionpages;
< 
<     /** @var mod_quiz_display_options cache for the appropriate review options. */
<     protected $reviewoptions = null;
< 
<     // Constructor =============================================================
<     /**
<      * Constructor assuming we already have the necessary data loaded.
<      *
<      * @param object $attempt the row of the quiz_attempts table.
<      * @param object $quiz the quiz object for this attempt and user.
<      * @param object $cm the course_module object for this quiz.
<      * @param object $course the row from the course table for the course we belong to.
<      * @param bool $loadquestions (optional) if true, the default, load all the details
<      *      of the state of each question. Else just set up the basic details of the attempt.
<      */
<     public function __construct($attempt, $quiz, $cm, $course, $loadquestions = true) {
<         $this->attempt = $attempt;
<         $this->quizobj = new quiz($quiz, $cm, $course);
< 
<         if ($loadquestions) {
<             $this->load_questions();
<         }
<     }
< 
<     /**
<      * Used by {create()} and {create_from_usage_id()}.
<      *
<      * @param array $conditions passed to $DB->get_record('quiz_attempts', $conditions).
<      * @return quiz_attempt the desired instance of this class.
<      */
<     protected static function create_helper($conditions) {
<         global $DB;
< 
<         $attempt = $DB->get_record('quiz_attempts', $conditions, '*', MUST_EXIST);
<         $quiz = quiz_access_manager::load_quiz_and_settings($attempt->quiz);
<         $course = $DB->get_record('course', array('id' => $quiz->course), '*', MUST_EXIST);
<         $cm = get_coursemodule_from_instance('quiz', $quiz->id, $course->id, false, MUST_EXIST);
< 
<         // Update quiz with override information.
<         $quiz = quiz_update_effective_access($quiz, $attempt->userid);
< 
<         return new quiz_attempt($attempt, $quiz, $cm, $course);
<     }
< 
<     /**
<      * Static function to create a new quiz_attempt object given an attemptid.
<      *
<      * @param int $attemptid the attempt id.
<      * @return quiz_attempt the new quiz_attempt object
<      */
<     public static function create($attemptid) {
<         return self::create_helper(array('id' => $attemptid));
<     }
< 
<     /**
<      * Static function to create a new quiz_attempt object given a usage id.
<      *
<      * @param int $usageid the attempt usage id.
<      * @return quiz_attempt the new quiz_attempt object
<      */
<     public static function create_from_usage_id($usageid) {
<         return self::create_helper(array('uniqueid' => $usageid));
<     }
< 
<     /**
<      * @param string $state one of the state constants like IN_PROGRESS.
<      * @return string the human-readable state name.
<      */
<     public static function state_name($state) {
<         return quiz_attempt_state_name($state);
<     }
< 
<     /**
<      * This method can be called later if the object was constructed with $loadqusetions = false.
<      */
<     public function load_questions() {
<         global $DB;
< 
<         if (isset($this->quba)) {
<             throw new coding_exception('This quiz attempt has already had the questions loaded.');
<         }
< 
<         $this->quba = question_engine::load_questions_usage_by_activity($this->attempt->uniqueid);
<         $this->slots = $DB->get_records('quiz_slots',
<                 array('quizid' => $this->get_quizid()), 'slot',
<                 'slot, id, requireprevious, questionid, includingsubcategories');
<         $this->sections = array_values($DB->get_records('quiz_sections',
<                 array('quizid' => $this->get_quizid()), 'firstslot'));
< 
<         $this->link_sections_and_slots();
<         $this->determine_layout();
<         $this->number_questions();
<     }
< 
<     /**
<      * Let each slot know which section it is part of.
<      */
<     protected function link_sections_and_slots() {
<         foreach ($this->sections as $i => $section) {
<             if (isset($this->sections[$i + 1])) {
<                 $section->lastslot = $this->sections[$i + 1]->firstslot - 1;
<             } else {
<                 $section->lastslot = count($this->slots);
<             }
<             for ($slot = $section->firstslot; $slot <= $section->lastslot; $slot += 1) {
<                 $this->slots[$slot]->section = $section;
<             }
<         }
<     }
< 
<     /**
<      * Parse attempt->layout to populate the other arrays the represent the layout.
<      */
<     protected function determine_layout() {
<         $this->pagelayout = array();
< 
<         // Break up the layout string into pages.
<         $pagelayouts = explode(',0', $this->attempt->layout);
< 
<         // Strip off any empty last page (normally there is one).
<         if (end($pagelayouts) == '') {
<             array_pop($pagelayouts);
<         }
< 
<         // File the ids into the arrays.
<         // Tracking which is the first slot in each section in this attempt is
<         // trickier than you might guess, since the slots in this section
<         // may be shuffled, so $section->firstslot (the lowest numbered slot in
<         // the section) may not be the first one.
<         $unseensections = $this->sections;
<         $this->pagelayout = array();
<         foreach ($pagelayouts as $page => $pagelayout) {
<             $pagelayout = trim($pagelayout, ',');
<             if ($pagelayout == '') {
<                 continue;
<             }
<             $this->pagelayout[$page] = explode(',', $pagelayout);
<             foreach ($this->pagelayout[$page] as $slot) {
<                 $sectionkey = array_search($this->slots[$slot]->section, $unseensections);
<                 if ($sectionkey !== false) {
<                     $this->slots[$slot]->firstinsection = true;
<                     unset($unseensections[$sectionkey]);
<                 } else {
<                     $this->slots[$slot]->firstinsection = false;
<                 }
<             }
<         }
<     }
< 
<     /**
<      * Work out the number to display for each question/slot.
<      */
<     protected function number_questions() {
<         $number = 1;
<         foreach ($this->pagelayout as $page => $slots) {
<             foreach ($slots as $slot) {
<                 if ($length = $this->is_real_question($slot)) {
<                     $this->questionnumbers[$slot] = $number;
<                     $number += $length;
<                 } else {
<                     $this->questionnumbers[$slot] = get_string('infoshort', 'quiz');
<                 }
<                 $this->questionpages[$slot] = $page;
<             }
<         }
<     }
< 
<     /**
<      * If the given page number is out of range (before the first page, or after
<      * the last page, chnage it to be within range).
<      *
<      * @param int $page the requested page number.
<      * @return int a safe page number to use.
<      */
<     public function force_page_number_into_range($page) {
<         return min(max($page, 0), count($this->pagelayout) - 1);
<     }
< 
<     // Simple getters ==========================================================
<     public function get_quiz() {
<         return $this->quizobj->get_quiz();
<     }
< 
<     public function get_quizobj() {
<         return $this->quizobj;
<     }
< 
<     /** @return int the course id. */
<     public function get_courseid() {
<         return $this->quizobj->get_courseid();
<     }
< 
<     /**
<      * Get the course settings object.
<      *
<      * @return stdClass the course settings object.
<      */
<     public function get_course() {
<         return $this->quizobj->get_course();
<     }
< 
<     /** @return int the quiz id. */
<     public function get_quizid() {
<         return $this->quizobj->get_quizid();
<     }
< 
<     /** @return string the name of this quiz. */
<     public function get_quiz_name() {
<         return $this->quizobj->get_quiz_name();
<     }
< 
<     /** @return int the quiz navigation method. */
<     public function get_navigation_method() {
<         return $this->quizobj->get_navigation_method();
<     }
< 
<     /** @return object the course_module object. */
<     public function get_cm() {
<         return $this->quizobj->get_cm();
<     }
< 
<     /**
<      * Get the course-module id.
<      *
<      * @return int the course_module id.
<      */
<     public function get_cmid() {
<         return $this->quizobj->get_cmid();
<     }
< 
<     /**
<      * @return bool whether the current user is someone who previews the quiz,
<      * rather than attempting it.
<      */
<     public function is_preview_user() {
<         return $this->quizobj->is_preview_user();
<     }
< 
<     /** @return int the number of attempts allowed at this quiz (0 = infinite). */
<     public function get_num_attempts_allowed() {
<         return $this->quizobj->get_num_attempts_allowed();
<     }
< 
<     /** @return int number fo pages in this quiz. */
<     public function get_num_pages() {
<         return count($this->pagelayout);
<     }
< 
<     /**
<      * @param int $timenow the current time as a unix timestamp.
<      * @return quiz_access_manager and instance of the quiz_access_manager class
<      *      for this quiz at this time.
<      */
<     public function get_access_manager($timenow) {
<         return $this->quizobj->get_access_manager($timenow);
<     }
< 
<     /** @return int the attempt id. */
<     public function get_attemptid() {
<         return $this->attempt->id;
<     }
< 
<     /** @return int the attempt unique id. */
<     public function get_uniqueid() {
<         return $this->attempt->uniqueid;
<     }
< 
<     /** @return object the row from the quiz_attempts table. */
<     public function get_attempt() {
<         return $this->attempt;
<     }
< 
<     /** @return int the number of this attemp (is it this user's first, second, ... attempt). */
<     public function get_attempt_number() {
<         return $this->attempt->attempt;
<     }
< 
<     /** @return string one of the quiz_attempt::IN_PROGRESS, FINISHED, OVERDUE or ABANDONED constants. */
<     public function get_state() {
<         return $this->attempt->state;
<     }
< 
<     /** @return int the id of the user this attempt belongs to. */
<     public function get_userid() {
<         return $this->attempt->userid;
<     }
< 
<     /** @return int the current page of the attempt. */
<     public function get_currentpage() {
<         return $this->attempt->currentpage;
<     }
< 
<     public function get_sum_marks() {
<         return $this->attempt->sumgrades;
<     }
< 
<     /**
<      * @return bool whether this attempt has been finished (true) or is still
<      *     in progress (false). Be warned that this is not just state == self::FINISHED,
<      *     it also includes self::ABANDONED.
<      */
<     public function is_finished() {
<         return $this->attempt->state == self::FINISHED || $this->attempt->state == self::ABANDONED;
<     }
< 
<     /** @return bool whether this attempt is a preview attempt. */
<     public function is_preview() {
<         return $this->attempt->preview;
<     }
< 
<     /**
<      * Is this someone dealing with their own attempt or preview?
<      *
<      * @return bool true => own attempt/preview. false => reviewing someone else's.
<      */
<     public function is_own_attempt() {
<         global $USER;
<         return $this->attempt->userid == $USER->id;
<     }
< 
<     /**
<      * @return bool whether this attempt is a preview belonging to the current user.
<      */
<     public function is_own_preview() {
<         return $this->is_own_attempt() &&
<                 $this->is_preview_user() && $this->attempt->preview;
<     }
< 
<     /**
<      * Is the current user allowed to review this attempt. This applies when
<      * {@link is_own_attempt()} returns false.
<      *
<      * @return bool whether the review should be allowed.
<      */
<     public function is_review_allowed() {
<         if (!$this->has_capability('mod/quiz:viewreports')) {
<             return false;
<         }
< 
<         $cm = $this->get_cm();
<         if ($this->has_capability('moodle/site:accessallgroups') ||
<                 groups_get_activity_groupmode($cm) != SEPARATEGROUPS) {
<             return true;
<         }
< 
<         // Check the users have at least one group in common.
<         $teachersgroups = groups_get_activity_allowed_groups($cm);
<         $studentsgroups = groups_get_all_groups(
<                 $cm->course, $this->attempt->userid, $cm->groupingid);
<         return $teachersgroups && $studentsgroups &&
<                 array_intersect(array_keys($teachersgroups), array_keys($studentsgroups));
<     }
< 
<     /**
<      * Has the student, in this attempt, engaged with the quiz in a non-trivial way?
<      *
<      * That is, is there any question worth a non-zero number of marks, where
<      * the student has made some response that we have saved?
<      *
<      * @return bool true if we have saved a response for at least one graded question.
<      */
<     public function has_response_to_at_least_one_graded_question() {
<         foreach ($this->quba->get_attempt_iterator() as $qa) {
<             if ($qa->get_max_mark() == 0) {
<                 continue;
<             }
<             if ($qa->get_num_steps() > 1) {
<                 return true;
<             }
<         }
<         return false;
<     }
< 
<     /**
<      * Get extra summary information about this attempt.
<      *
<      * Some behaviours may be able to provide interesting summary information
<      * about the attempt as a whole, and this method provides access to that data.
<      * To see how this works, try setting a quiz to one of the CBM behaviours,
<      * and then look at the extra information displayed at the top of the quiz
<      * review page once you have sumitted an attempt.
<      *
<      * In the return value, the array keys are identifiers of the form
<      * qbehaviour_behaviourname_meaningfullkey. For qbehaviour_deferredcbm_highsummary.
<      * The values are arrays with two items, title and content. Each of these
<      * will be either a string, or a renderable.
<      *
<      * @param question_display_options $options the display options for this quiz attempt at this time.
<      * @return array as described above.
<      */
<     public function get_additional_summary_data(question_display_options $options) {
<         return $this->quba->get_summary_information($options);
<     }
< 
<     /**
<      * Get the overall feedback corresponding to a particular mark.
<      *
<      * @param number $grade a particular grade.
<      * @return string the feedback.
<      */
<     public function get_overall_feedback($grade) {
<         return quiz_feedback_for_grade($grade, $this->get_quiz(),
<                 $this->quizobj->get_context());
<     }
< 
<     /**
<      * Wrapper round the has_capability funciton that automatically passes in the quiz context.
<      *
<      * @param string $capability the name of the capability to check. For example mod/forum:view.
<      * @param int|null $userid A user id. By default (null) checks the permissions of the current user.
<      * @param bool $doanything If false, ignore effect of admin role assignment.
<      * @return boolean true if the user has this capability. Otherwise false.
<      */
<     public function has_capability($capability, $userid = null, $doanything = true) {
<         return $this->quizobj->has_capability($capability, $userid, $doanything);
<     }
< 
<     /**
<      * Wrapper round the require_capability function that automatically passes in the quiz context.
<      *
<      * @param string $capability the name of the capability to check. For example mod/forum:view.
<      * @param int|null $userid A user id. By default (null) checks the permissions of the current user.
<      * @param bool $doanything If false, ignore effect of admin role assignment.
<      */
<     public function require_capability($capability, $userid = null, $doanything = true) {
<         $this->quizobj->require_capability($capability, $userid, $doanything);
<     }
< 
<     /**
<      * Check the appropriate capability to see whether this user may review their own attempt.
<      * If not, prints an error.
<      */
<     public function check_review_capability() {
<         if ($this->get_attempt_state() == mod_quiz_display_options::IMMEDIATELY_AFTER) {
<             $capability = 'mod/quiz:attempt';
<         } else {
<             $capability = 'mod/quiz:reviewmyattempts';
<         }
< 
<         // These next tests are in a slighly funny order. The point is that the
<         // common and most performance-critical case is students attempting a quiz
<         // so we want to check that permisison first.
< 
<         if ($this->has_capability($capability)) {
<             // User has the permission that lets you do the quiz as a student. Fine.
<             return;
<         }
< 
<         if ($this->has_capability('mod/quiz:viewreports') ||
<                 $this->has_capability('mod/quiz:preview')) {
<             // User has the permission that lets teachers review. Fine.
<             return;
<         }
< 
<         // They should not be here. Trigger the standard no-permission error
<         // but using the name of the student capability.
<         // We know this will fail. We just want the stadard exception thown.
<         $this->require_capability($capability);
<     }
< 
<     /**
<      * Checks whether a user may navigate to a particular slot.
<      *
<      * @param int $slot the target slot (currently does not affect the answer).
<      * @return bool true if the navigation should be allowed.
<      */
<     public function can_navigate_to($slot) {
<         if ($this->attempt->state == self::OVERDUE) {
<             // When the attempt is overdue, students can only see the
<             // attempt summary page and cannot navigate anywhere else.
<             return false;
<         }
< 
<         switch ($this->get_navigation_method()) {
<             case QUIZ_NAVMETHOD_FREE:
<                 return true;
<                 break;
<             case QUIZ_NAVMETHOD_SEQ:
<                 return false;
<                 break;
<         }
<         return true;
<     }
< 
<     /**
<      * @return int one of the mod_quiz_display_options::DURING,
<      *      IMMEDIATELY_AFTER, LATER_WHILE_OPEN or AFTER_CLOSE constants.
<      */
<     public function get_attempt_state() {
<         return quiz_attempt_state($this->get_quiz(), $this->attempt);
<     }
< 
<     /**
<      * Wrapper that the correct mod_quiz_display_options for this quiz at the
<      * moment.
<      *
<      * @param bool $reviewing true for options when reviewing, false for when attempting.
<      * @return question_display_options the render options for this user on this attempt.
<      */
<     public function get_display_options($reviewing) {
<         if ($reviewing) {
<             if (is_null($this->reviewoptions)) {
<                 $this->reviewoptions = quiz_get_review_options($this->get_quiz(),
<                         $this->attempt, $this->quizobj->get_context());
<                 if ($this->is_own_preview()) {
<                     // It should  always be possible for a teacher to review their
<                     // own preview irrespective of the review options settings.
<                     $this->reviewoptions->attempt = true;
<                 }
<             }
<             return $this->reviewoptions;
< 
<         } else {
<             $options = mod_quiz_display_options::make_from_quiz($this->get_quiz(),
<                     mod_quiz_display_options::DURING);
<             $options->flags = quiz_get_flag_option($this->attempt, $this->quizobj->get_context());
<             return $options;
<         }
<     }
< 
<     /**
<      * Wrapper that the correct mod_quiz_display_options for this quiz at the
<      * moment.
<      *
<      * @param bool $reviewing true for review page, else attempt page.
<      * @param int $slot which question is being displayed.
<      * @param moodle_url $thispageurl to return to after the editing form is
<      *      submitted or cancelled. If null, no edit link will be generated.
<      *
<      * @return question_display_options the render options for this user on this
<      *      attempt, with extra info to generate an edit link, if applicable.
<      */
<     public function get_display_options_with_edit_link($reviewing, $slot, $thispageurl) {
<         $options = clone($this->get_display_options($reviewing));
< 
<         if (!$thispageurl) {
<             return $options;
<         }
< 
<         if (!($reviewing || $this->is_preview())) {
<             return $options;
<         }
< 
<         $question = $this->quba->get_question($slot, false);
<         if (!question_has_capability_on($question, 'edit', $question->category)) {
<             return $options;
<         }
< 
<         $options->editquestionparams['cmid'] = $this->get_cmid();
<         $options->editquestionparams['returnurl'] = $thispageurl;
< 
<         return $options;
<     }
< 
<     /**
<      * @param int $page page number
<      * @return bool true if this is the last page of the quiz.
<      */
<     public function is_last_page($page) {
<         return $page == count($this->pagelayout) - 1;
<     }
< 
<     /**
<      * Return the list of slot numbers for either a given page of the quiz, or for the
<      * whole quiz.
<      *
<      * @param mixed $page string 'all' or integer page number.
<      * @return array the requested list of slot numbers.
<      */
<     public function get_slots($page = 'all') {
<         if ($page === 'all') {
<             $numbers = array();
<             foreach ($this->pagelayout as $numbersonpage) {
<                 $numbers = array_merge($numbers, $numbersonpage);
<             }
<             return $numbers;
<         } else {
<             return $this->pagelayout[$page];
<         }
<     }
< 
<     /**
<      * Return the list of slot numbers for either a given page of the quiz, or for the
<      * whole quiz.
<      *
<      * @param mixed $page string 'all' or integer page number.
<      * @return array the requested list of slot numbers.
<      */
<     public function get_active_slots($page = 'all') {
<         $activeslots = array();
<         foreach ($this->get_slots($page) as $slot) {
<             if (!$this->is_blocked_by_previous_question($slot)) {
<                 $activeslots[] = $slot;
<             }
<         }
<         return $activeslots;
<     }
< 
<     /**
<      * Helper method for unit tests. Get the underlying question usage object.
<      *
<      * @return question_usage_by_activity the usage.
<      */
<     public function get_question_usage() {
<         if (!(PHPUNIT_TEST || defined('BEHAT_TEST'))) {
<             throw new coding_exception('get_question_usage is only for use in unit tests. ' .
<                     'For other operations, use the quiz_attempt api, or extend it properly.');
<         }
<         return $this->quba;
<     }
< 
<     /**
<      * Get the question_attempt object for a particular question in this attempt.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return question_attempt the requested question_attempt.
<      */
<     public function get_question_attempt($slot) {
<         return $this->quba->get_question_attempt($slot);
<     }
< 
<     /**
<      * Get all the question_attempt objects that have ever appeared in a given slot.
<      *
<      * This relates to the 'Try another question like this one' feature.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return question_attempt[] the attempts.
<      */
<     public function all_question_attempts_originally_in_slot($slot) {
<         $qas = array();
<         foreach ($this->quba->get_attempt_iterator() as $qa) {
<             if ($qa->get_metadata('originalslot') == $slot) {
<                 $qas[] = $qa;
<             }
<         }
<         $qas[] = $this->quba->get_question_attempt($slot);
<         return $qas;
<     }
< 
<     /**
<      * Is a particular question in this attempt a real question, or something like a description.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return int whether that question is a real question. Actually returns the
<      *     question length, which could theoretically be greater than one.
<      */
<     public function is_real_question($slot) {
<         return $this->quba->get_question($slot, false)->length;
<     }
< 
<     /**
<      * Is a particular question in this attempt a real question, or something like a description.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return bool whether that question is a real question.
<      */
<     public function is_question_flagged($slot) {
<         return $this->quba->get_question_attempt($slot)->is_flagged();
<     }
< 
<     /**
<      * Checks whether the question in this slot requires the previous
<      * question to have been completed.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return bool whether the previous question must have been completed before
<      *      this one can be seen.
<      */
<     public function is_blocked_by_previous_question($slot) {
<         return $slot > 1 && isset($this->slots[$slot]) && $this->slots[$slot]->requireprevious &&
<                 !$this->slots[$slot]->section->shufflequestions &&
<                 !$this->slots[$slot - 1]->section->shufflequestions &&
<                 $this->get_navigation_method() != QUIZ_NAVMETHOD_SEQ &&
<                 !$this->get_question_state($slot - 1)->is_finished() &&
<                 $this->quba->can_question_finish_during_attempt($slot - 1);
<     }
< 
<     /**
<      * Is it possible for this question to be re-started within this attempt?
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return bool whether the student should be given the option to restart this question now.
<      */
<     public function can_question_be_redone_now($slot) {
<         return $this->get_quiz()->canredoquestions && !$this->is_finished() &&
<                 $this->get_question_state($slot)->is_finished();
<     }



    /**

<      * Given a slot in this attempt, which may or not be a redone question, return the original slot.



>  * File only retained to prevent fatal errors in code that tries to require/include this.


     *

<      * @param int $slot identifies a particular question in this attempt.
<      * @return int the slot where this question was originally.



>  * @todo MDL-76612 delete this file as part of Moodle 4.6 development.
>  * @deprecated This file is no longer required in Moodle 4.2+.


     */

<     public function get_original_slot($slot) {
<         $originalslot = $this->quba->get_question_attempt_metadata($slot, 'originalslot');
<         if ($originalslot) {
<             return $originalslot;
<         } else {
<             return $slot;
<         }
<     }
< 
<     /**
<      * Get the displayed question number for a slot.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return string the displayed question number for the question in this slot.
<      *      For example '1', '2', '3' or 'i'.
<      */
<     public function get_question_number($slot) {
<         return $this->questionnumbers[$slot];
<     }
< 
<     /**
<      * If the section heading, if any, that should come just before this slot.
<      *
<      * @param int $slot identifies a particular question in this attempt.
<      * @return string the required heading, or null if there is not one here.
<      */
<     public function get_heading_before_slot($slot) {
<         if ($this->slots[$slot]->firstinsection) {
<             return $this->slots[$slot]->section->heading;
<         } else {
<             return null;
<         }
<     }
< 
<     /**
<      * Return the page of the quiz where this question appears.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return int the page of the quiz this question appears on.
<      */
<     public function get_question_page($slot) {
<         return $this->questionpages[$slot];
<     }
< 
<     /**
<      * Return the grade obtained on a particular question, if the user is permitted
<      * to see it. You must previously have called load_question_states to load the
<      * state data about this question.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return string the formatted grade, to the number of decimal places specified
<      *      by the quiz.
<      */
<     public function get_question_name($slot) {
<         return $this->quba->get_question($slot, false)->name;
<     }
< 
<     /**
<      * Return the {@link question_state} that this question is in.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return question_state the state this question is in.
<      */
<     public function get_question_state($slot) {
<         return $this->quba->get_question_state($slot);
<     }
< 
<     /**
<      * Return the grade obtained on a particular question, if the user is permitted
<      * to see it. You must previously have called load_question_states to load the
<      * state data about this question.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @param bool $showcorrectness Whether right/partial/wrong states should
<      *      be distinguished.
<      * @return string the formatted grade, to the number of decimal places specified
<      *      by the quiz.
<      */
<     public function get_question_status($slot, $showcorrectness) {
<         return $this->quba->get_question_state_string($slot, $showcorrectness);
<     }
< 
<     /**
<      * Return the grade obtained on a particular question, if the user is permitted
<      * to see it. You must previously have called load_question_states to load the
<      * state data about this question.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @param bool $showcorrectness Whether right/partial/wrong states should
<      *      be distinguished.
<      * @return string class name for this state.
<      */
<     public function get_question_state_class($slot, $showcorrectness) {
<         return $this->quba->get_question_state_class($slot, $showcorrectness);
<     }
< 
<     /**
<      * Return the grade obtained on a particular question.
<      *
<      * You must previously have called load_question_states to load the state
<      * data about this question.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return string the formatted grade, to the number of decimal places specified by the quiz.
<      */
<     public function get_question_mark($slot) {
<         return quiz_format_question_grade($this->get_quiz(), $this->quba->get_question_mark($slot));
<     }
< 
<     /**
<      * Get the time of the most recent action performed on a question.
<      *
<      * @param int $slot the number used to identify this question within this usage.
<      * @return int timestamp.
<      */
<     public function get_question_action_time($slot) {
<         return $this->quba->get_question_action_time($slot);
<     }
< 
<     /**
<      * Return the question type name for a given slot within the current attempt.
<      *
<      * @param int $slot the number used to identify this question within this attempt.
<      * @return string the question type name.
<      * @since  Moodle 3.1
<      */
<     public function get_question_type_name($slot) {
<         return $this->quba->get_question($slot, false)->get_type_name();
<     }
< 
<     /**
<      * Get the time remaining for an in-progress attempt, if the time is short
<      * enough that it would be worth showing a timer.
<      *
<      * @param int $timenow the time to consider as 'now'.
<      * @return int|false the number of seconds remaining for this attempt.
<      *      False if there is no limit.
<      */
<     public function get_time_left_display($timenow) {
<         if ($this->attempt->state != self::IN_PROGRESS) {
<             return false;
<         }
<         return $this->get_access_manager($timenow)->get_time_left_display($this->attempt, $timenow);
<     }
< 
< 
<     /**
<      * @return int the time when this attempt was submitted. 0 if it has not been
<      * submitted yet.
<      */
<     public function get_submitted_date() {
<         return $this->attempt->timefinish;
<     }
< 
<     /**
<      * If the attempt is in an applicable state, work out the time by which the
<      * student should next do something.
<      *
<      * @return int timestamp by which the student needs to do something.
<      */
<     public function get_due_date() {
<         $deadlines = array();
<         if ($this->quizobj->get_quiz()->timelimit) {
<             $deadlines[] = $this->attempt->timestart + $this->quizobj->get_quiz()->timelimit;
<         }
<         if ($this->quizobj->get_quiz()->timeclose) {
<             $deadlines[] = $this->quizobj->get_quiz()->timeclose;
<         }
<         if ($deadlines) {
<             $duedate = min($deadlines);
<         } else {
<             return false;
<         }
< 
<         switch ($this->attempt->state) {
<             case self::IN_PROGRESS:
<                 return $duedate;
< 
<             case self::OVERDUE:
<                 return $duedate + $this->quizobj->get_quiz()->graceperiod;
< 
<             default:
<                 throw new coding_exception('Unexpected state: ' . $this->attempt->state);
<         }
<     }
< 
<     // URLs related to this attempt ============================================
<     /**
<      * @return string quiz view url.
<      */
<     public function view_url() {
<         return $this->quizobj->view_url();
<     }
< 
<     /**
<      * Get the URL to start or continue an attempt.
<      *
<      * @param int|null $slot which question in the attempt to go to after starting (optional).
<      * @param int $page which page in the attempt to go to after starting.
<      * @return string the URL of this quiz's edit page. Needs to be POSTed to with a cmid parameter.
<      */
<     public function start_attempt_url($slot = null, $page = -1) {
<         if ($page == -1 && !is_null($slot)) {
<             $page = $this->get_question_page($slot);
<         } else {
<             $page = 0;
<         }
<         return $this->quizobj->start_attempt_url($page);
<     }
< 
<     /**
<      * Generates the title of the attempt page.
<      *
<      * @param int $page the page number (starting with 0) in the attempt.
<      * @return string attempt page title.
<      */
<     public function attempt_page_title(int $page) : string {
<         if ($this->get_num_pages() > 1) {
<             $a = new stdClass();
<             $a->name = $this->get_quiz_name();
<             $a->currentpage = $page + 1;
<             $a->totalpages = $this->get_num_pages();
<             $title = get_string('attempttitlepaged', 'quiz', $a);
<         } else {
<             $title = get_string('attempttitle', 'quiz', $this->get_quiz_name());
<         }
< 
<         return $title;
<     }
< 
<     /**
<      * @param int|null $slot if specified, the slot number of a specific question to link to.
<      * @param int $page if specified, a particular page to link to. If not given deduced
<      *      from $slot, or goes to the first page.
<      * @param int $thispage if not -1, the current page. Will cause links to other things on
<      * this page to be output as only a fragment.
<      * @return string the URL to continue this attempt.
<      */
<     public function attempt_url($slot = null, $page = -1, $thispage = -1) {
<         return $this->page_and_question_url('attempt', $slot, $page, false, $thispage);
<     }
< 
<     /**
<      * Generates the title of the summary page.
<      *
<      * @return string summary page title.
<      */
<     public function summary_page_title() : string {
<         return get_string('attemptsummarytitle', 'quiz', $this->get_quiz_name());
<     }
< 
<     /**
<      * @return moodle_url the URL of this quiz's summary page.
<      */
<     public function summary_url() {
<         return new moodle_url('/mod/quiz/summary.php', array('attempt' => $this->attempt->id, 'cmid' => $this->get_cmid()));
<     }
< 
<     /**
<      * @return moodle_url the URL of this quiz's summary page.
<      */
<     public function processattempt_url() {
<         return new moodle_url('/mod/quiz/processattempt.php');
<     }
< 
<     /**
<      * Generates the title of the review page.
<      *
<      * @param int $page the page number (starting with 0) in the attempt.
<      * @param bool $showall whether the review page contains the entire attempt on one page.
<      * @return string title of the review page.
<      */
<     public function review_page_title(int $page, bool $showall = false) : string {
<         if (!$showall && $this->get_num_pages() > 1) {
<             $a = new stdClass();
<             $a->name = $this->get_quiz_name();
<             $a->currentpage = $page + 1;
<             $a->totalpages = $this->get_num_pages();
<             $title = get_string('attemptreviewtitlepaged', 'quiz', $a);
<         } else {
<             $title = get_string('attemptreviewtitle', 'quiz', $this->get_quiz_name());
<         }
< 
<         return $title;
<     }
< 
<     /**
<      * @param int|null $slot indicates which question to link to.
<      * @param int $page if specified, the URL of this particular page of the attempt, otherwise
<      *      the URL will go to the first page.  If -1, deduce $page from $slot.
<      * @param bool|null $showall if true, the URL will be to review the entire attempt on one page,
<      *      and $page will be ignored. If null, a sensible default will be chosen.
<      * @param int $thispage if not -1, the current page. Will cause links to other things on
<      *      this page to be output as only a fragment.
<      * @return string the URL to review this attempt.
<      */
<     public function review_url($slot = null, $page = -1, $showall = null, $thispage = -1) {
<         return $this->page_and_question_url('review', $slot, $page, $showall, $thispage);
<     }
< 
<     /**
<      * By default, should this script show all questions on one page for this attempt?
<      *
<      * @param string $script the script name, e.g. 'attempt', 'summary', 'review'.
<      * @return bool whether show all on one page should be on by default.
<      */
<     public function get_default_show_all($script) {
<         return $script == 'review' && count($this->questionpages) < self::MAX_SLOTS_FOR_DEFAULT_REVIEW_SHOW_ALL;
<     }
< 
<     // Bits of content =========================================================
< 
<     /**
<      * If $reviewoptions->attempt is false, meaning that students can't review this
<      * attempt at the moment, return an appropriate string explaining why.
<      *
<      * @param bool $short if true, return a shorter string.
<      * @return string an appropriate message.
<      */
<     public function cannot_review_message($short = false) {
<         return $this->quizobj->cannot_review_message(
<                 $this->get_attempt_state(), $short);
<     }
< 
<     /**
<      * Initialise the JS etc. required all the questions on a page.
<      *
<      * @param int|string $page a page number, or 'all'.
<      * @param bool $showall if true forces page number to all.
<      * @return string HTML to output - mostly obsolete, will probably be an empty string.
<      */
<     public function get_html_head_contributions($page = 'all', $showall = false) {
<         if ($showall) {
<             $page = 'all';
<         }
<         $result = '';
<         foreach ($this->get_slots($page) as $slot) {
<             $result .= $this->quba->render_question_head_html($slot);
<         }
<         $result .= question_engine::initialise_js();
<         return $result;
<     }
< 
<     /**
<      * Initialise the JS etc. required by one question.
<      *
<      * @param int $slot the question slot number.
<      * @return string HTML to output - but this is mostly obsolete. Will probably be an empty string.
<      */
<     public function get_question_html_head_contributions($slot) {
<         return $this->quba->render_question_head_html($slot) .
<                 question_engine::initialise_js();
<     }
< 
<     /**
<      * Print the HTML for the start new preview button, if the current user
<      * is allowed to see one.
<      *
<      * @return string HTML for the button.
<      */
<     public function restart_preview_button() {
<         global $OUTPUT;
<         if ($this->is_preview() && $this->is_preview_user()) {
<             return $OUTPUT->single_button(new moodle_url(
<                     $this->start_attempt_url(), array('forcenew' => true)),
<                     get_string('startnewpreview', 'quiz'));
<         } else {
<             return '';
<         }
<     }
< 
<     /**
<      * Generate the HTML that displayes the question in its current state, with
<      * the appropriate display options.
<      *
<      * @param int $slot identifies the question in the attempt.
<      * @param bool $reviewing is the being printed on an attempt or a review page.
<      * @param mod_quiz_renderer $renderer the quiz renderer.
<      * @param moodle_url $thispageurl the URL of the page this question is being printed on.
<      * @return string HTML for the question in its current state.
<      */
<     public function render_question($slot, $reviewing, mod_quiz_renderer $renderer, $thispageurl = null) {
<         if ($this->is_blocked_by_previous_question($slot)) {
<             $placeholderqa = $this->make_blocked_question_placeholder($slot);
< 
<             $displayoptions = $this->get_display_options($reviewing);
<             $displayoptions->manualcomment = question_display_options::HIDDEN;
<             $displayoptions->history = question_display_options::HIDDEN;
<             $displayoptions->readonly = true;
< 
<             return html_writer::div($placeholderqa->render($displayoptions,
<                     $this->get_question_number($this->get_original_slot($slot))),
<                     'mod_quiz-blocked_question_warning');
<         }
< 
<         return $this->render_question_helper($slot, $reviewing, $thispageurl, $renderer, null);
<     }
< 
<     /**
<      * Helper used by {@link render_question()} and {@link render_question_at_step()}.
<      *
<      * @param int $slot identifies the question in the attempt.
<      * @param bool $reviewing is the being printed on an attempt or a review page.
<      * @param moodle_url $thispageurl the URL of the page this question is being printed on.
<      * @param mod_quiz_renderer $renderer the quiz renderer.
<      * @param int|null $seq the seq number of the past state to display.
<      * @return string HTML fragment.
<      */
<     protected function render_question_helper($slot, $reviewing, $thispageurl,
<             mod_quiz_renderer $renderer, $seq) {
<         $originalslot = $this->get_original_slot($slot);
<         $number = $this->get_question_number($originalslot);
<         $displayoptions = $this->get_display_options_with_edit_link($reviewing, $slot, $thispageurl);
< 
<         if ($slot != $originalslot) {
<             $originalmaxmark = $this->get_question_attempt($slot)->get_max_mark();
<             $this->get_question_attempt($slot)->set_max_mark($this->get_question_attempt($originalslot)->get_max_mark());
<         }
< 
<         if ($this->can_question_be_redone_now($slot)) {
<             $displayoptions->extrainfocontent = $renderer->redo_question_button(
<                     $slot, $displayoptions->readonly);
<         }
< 
<         if ($displayoptions->history && $displayoptions->questionreviewlink) {
<             $links = $this->links_to_other_redos($slot, $displayoptions->questionreviewlink);
<             if ($links) {
<                 $displayoptions->extrahistorycontent = html_writer::tag('p',
<                         get_string('redoesofthisquestion', 'quiz', $renderer->render($links)));
<             }
<         }
< 
<         if ($seq === null) {
<             $output = $this->quba->render_question($slot, $displayoptions, $number);
<         } else {
<             $output = $this->quba->render_question_at_step($slot, $seq, $displayoptions, $number);
<         }
< 
<         if ($slot != $originalslot) {
<             $this->get_question_attempt($slot)->set_max_mark($originalmaxmark);
<         }
< 
<         return $output;
<     }
< 
<     /**
<      * Create a fake question to be displayed in place of a question that is blocked
<      * until the previous question has been answered.
<      *
<      * @param int $slot int slot number of the question to replace.
<      * @return question_attempt the placeholder question attempt.
<      */
<     protected function make_blocked_question_placeholder($slot) {
<         $replacedquestion = $this->get_question_attempt($slot)->get_question(false);
< 
<         question_bank::load_question_definition_classes('description');
<         $question = new qtype_description_question();
<         $question->id = $replacedquestion->id;
<         $question->category = null;
<         $question->parent = 0;
<         $question->qtype = question_bank::get_qtype('description');
<         $question->name = '';
<         $question->questiontext = get_string('questiondependsonprevious', 'quiz');
<         $question->questiontextformat = FORMAT_HTML;
<         $question->generalfeedback = '';
<         $question->defaultmark = $this->quba->get_question_max_mark($slot);
<         $question->length = $replacedquestion->length;
<         $question->penalty = 0;
<         $question->stamp = '';
<         $question->version = 0;
<         $question->hidden = 0;
<         $question->timecreated = null;
<         $question->timemodified = null;
<         $question->createdby = null;
<         $question->modifiedby = null;
< 
<         $placeholderqa = new question_attempt($question, $this->quba->get_id(),
<                 null, $this->quba->get_question_max_mark($slot));
<         $placeholderqa->set_slot($slot);
<         $placeholderqa->start($this->get_quiz()->preferredbehaviour, 1);
<         $placeholderqa->set_flagged($this->is_question_flagged($slot));
<         return $placeholderqa;
<     }
< 
<     /**
<      * Like {@link render_question()} but displays the question at the past step
<      * indicated by $seq, rather than showing the latest step.
<      *
<      * @param int $slot the slot number of a question in this quiz attempt.
<      * @param int $seq the seq number of the past state to display.
<      * @param bool $reviewing is the being printed on an attempt or a review page.
<      * @param mod_quiz_renderer $renderer the quiz renderer.
<      * @param moodle_url $thispageurl the URL of the page this question is being printed on.
<      * @return string HTML for the question in its current state.
<      */
<     public function render_question_at_step($slot, $seq, $reviewing,
<             mod_quiz_renderer $renderer, $thispageurl = null) {
<         return $this->render_question_helper($slot, $reviewing, $thispageurl, $renderer, $seq);
<     }
< 
<     /**
<      * Wrapper round print_question from lib/questionlib.php.
<      *
<      * @param int $slot the id of a question in this quiz attempt.
<      * @return string HTML of the question.
<      */
<     public function render_question_for_commenting($slot) {
<         $options = $this->get_display_options(true);
<         $options->hide_all_feedback();
<         $options->manualcomment = question_display_options::EDITABLE;
<         return $this->quba->render_question($slot, $options,
<                 $this->get_question_number($slot));
<     }
< 
<     /**
<      * Check wheter access should be allowed to a particular file.
<      *
<      * @param int $slot the slot of a question in this quiz attempt.
<      * @param bool $reviewing is the being printed on an attempt or a review page.
<      * @param int $contextid the file context id from the request.
<      * @param string $component the file component from the request.
<      * @param string $filearea the file area from the request.
<      * @param array $args extra part components from the request.
<      * @param bool $forcedownload whether to force download.
<      * @return string HTML for the question in its current state.
<      */
<     public function check_file_access($slot, $reviewing, $contextid, $component,
<             $filearea, $args, $forcedownload) {
<         $options = $this->get_display_options($reviewing);
< 
<         // Check permissions - warning there is similar code in review.php and
<         // reviewquestion.php. If you change on, change them all.
<         if ($reviewing && $this->is_own_attempt() && !$options->attempt) {
<             return false;
<         }
< 
<         if ($reviewing && !$this->is_own_attempt() && !$this->is_review_allowed()) {
<             return false;
<         }
< 
<         return $this->quba->check_file_access($slot, $options,
<                 $component, $filearea, $args, $forcedownload);
<     }
< 
<     /**
<      * Get the navigation panel object for this attempt.
<      *
<      * @param mod_quiz_renderer $output the quiz renderer to use to output things.
<      * @param string $panelclass The type of panel, quiz_attempt_nav_panel or quiz_review_nav_panel
<      * @param int $page the current page number.
<      * @param bool $showall whether we are showing the whole quiz on one page. (Used by review.php.)
<      * @return block_contents the requested object.
<      */
<     public function get_navigation_panel(mod_quiz_renderer $output,
<              $panelclass, $page, $showall = false) {
<         $panel = new $panelclass($this, $this->get_display_options(true), $page, $showall);
< 
<         $bc = new block_contents();
<         $bc->attributes['id'] = 'mod_quiz_navblock';
<         $bc->attributes['role'] = 'navigation';
<         $bc->attributes['aria-labelledby'] = 'mod_quiz_navblock_title';
<         $bc->title = html_writer::span(get_string('quiznavigation', 'quiz'), '', array('id' => 'mod_quiz_navblock_title'));
<         $bc->content = $output->navigation_panel($panel);
<         return $bc;
<     }
< 
<     /**
<      * Return an array of variant URLs to other attempts at this quiz.
<      *
<      * The $url passed in must contain an attempt parameter.
<      *
<      * The {@link mod_quiz_links_to_other_attempts} object returned contains an
<      * array with keys that are the attempt number, 1, 2, 3.
<      * The array values are either a {@link moodle_url} with the attempt parameter
<      * updated to point to the attempt id of the other attempt, or null corresponding
<      * to the current attempt number.
<      *
<      * @param moodle_url $url a URL.
<      * @return mod_quiz_links_to_other_attempts|bool containing array int => null|moodle_url.
<      *      False if none.
<      */
<     public function links_to_other_attempts(moodle_url $url) {
<         $attempts = quiz_get_user_attempts($this->get_quiz()->id, $this->attempt->userid, 'all');
<         if (count($attempts) <= 1) {
<             return false;
<         }
< 
<         $links = new mod_quiz_links_to_other_attempts();
<         foreach ($attempts as $at) {
<             if ($at->id == $this->attempt->id) {
<                 $links->links[$at->attempt] = null;
<             } else {
<                 $links->links[$at->attempt] = new moodle_url($url, array('attempt' => $at->id));
<             }
<         }
<         return $links;
<     }
< 
<     /**
<      * Return an array of variant URLs to other redos of the question in a particular slot.
<      *
<      * The $url passed in must contain a slot parameter.
<      *
<      * The {@link mod_quiz_links_to_other_attempts} object returned contains an
<      * array with keys that are the redo number, 1, 2, 3.
<      * The array values are either a {@link moodle_url} with the slot parameter
<      * updated to point to the slot that has that redo of this question; or null
<      * corresponding to the redo identified by $slot.
<      *
<      * @param int $slot identifies a question in this attempt.
<      * @param moodle_url $baseurl the base URL to modify to generate each link.
<      * @return mod_quiz_links_to_other_attempts|null containing array int => null|moodle_url,
<      *      or null if the question in this slot has not been redone.
<      */
<     public function links_to_other_redos($slot, moodle_url $baseurl) {
<         $originalslot = $this->get_original_slot($slot);
< 
<         $qas = $this->all_question_attempts_originally_in_slot($originalslot);
<         if (count($qas) <= 1) {
<             return null;
<         }
< 
<         $links = new mod_quiz_links_to_other_attempts();
<         $index = 1;
<         foreach ($qas as $qa) {
<             if ($qa->get_slot() == $slot) {
<                 $links->links[$index] = null;
<             } else {
<                 $url = new moodle_url($baseurl, array('slot' => $qa->get_slot()));
<                 $links->links[$index] = new action_link($url, $index,
<                         new popup_action('click', $url, 'reviewquestion',
<                                 array('width' => 450, 'height' => 650)),
<                         array('title' => get_string('reviewresponse', 'question')));
<             }
<             $index++;
<         }
<         return $links;
<     }
< 
<     // Methods for processing ==================================================
< 
<     /**
<      * Check this attempt, to see if there are any state transitions that should
<      * happen automatically. This function will update the attempt checkstatetime.
<      * @param int $timestamp the timestamp that should be stored as the modified
<      * @param bool $studentisonline is the student currently interacting with Moodle?
<      */
<     public function handle_if_time_expired($timestamp, $studentisonline) {
< 
<         $timeclose = $this->get_access_manager($timestamp)->get_end_time($this->attempt);
< 
<         if ($timeclose === false || $this->is_preview()) {
<             $this->update_timecheckstate(null);
<             return; // No time limit.
<         }
<         if ($timestamp < $timeclose) {
<             $this->update_timecheckstate($timeclose);
<             return; // Time has not yet expired.
<         }
< 
<         // If the attempt is already overdue, look to see if it should be abandoned ...
<         if ($this->attempt->state == self::OVERDUE) {
<             $timeoverdue = $timestamp - $timeclose;
<             $graceperiod = $this->quizobj->get_quiz()->graceperiod;
<             if ($timeoverdue >= $graceperiod) {
<                 $this->process_abandon($timestamp, $studentisonline);
<             } else {
<                 // Overdue time has not yet expired
<                 $this->update_timecheckstate($timeclose + $graceperiod);
<             }
<             return; // ... and we are done.
<         }
< 
<         if ($this->attempt->state != self::IN_PROGRESS) {
<             $this->update_timecheckstate(null);
<             return; // Attempt is already in a final state.
<         }
< 
<         // Otherwise, we were in quiz_attempt::IN_PROGRESS, and time has now expired.
<         // Transition to the appropriate state.
<         switch ($this->quizobj->get_quiz()->overduehandling) {
<             case 'autosubmit':
<                 $this->process_finish($timestamp, false, $studentisonline ? $timestamp : $timeclose);
<                 return;
< 
<             case 'graceperiod':
<                 $this->process_going_overdue($timestamp, $studentisonline);
<                 return;
< 
<             case 'autoabandon':
<                 $this->process_abandon($timestamp, $studentisonline);
<                 return;
<         }
< 
<         // This is an overdue attempt with no overdue handling defined, so just abandon.
<         $this->process_abandon($timestamp, $studentisonline);
<         return;
<     }
< 
<     /**
<      * Process all the actions that were submitted as part of the current request.
<      *
<      * @param int $timestamp the timestamp that should be stored as the modified.
<      *      time in the database for these actions. If null, will use the current time.
<      * @param bool $becomingoverdue
<      * @param array|null $simulatedresponses If not null, then we are testing, and this is an array of simulated data.
<      *      There are two formats supported here, for historical reasons. The newer approach is to pass an array created by
<      *      {@link core_question_generator::get_simulated_post_data_for_questions_in_usage()}.
<      *      the second is to pass an array slot no => contains arrays representing student
<      *      responses which will be passed to {@link question_definition::prepare_simulated_post_data()}.
<      *      This second method will probably get deprecated one day.
<      */
<     public function process_submitted_actions($timestamp, $becomingoverdue = false, $simulatedresponses = null) {
<         global $DB;
< 
<         $transaction = $DB->start_delegated_transaction();
< 
<         if ($simulatedresponses !== null) {
<             if (is_int(key($simulatedresponses))) {
<                 // Legacy approach. Should be removed one day.
<                 $simulatedpostdata = $this->quba->prepare_simulated_post_data($simulatedresponses);
<             } else {
<                 $simulatedpostdata = $simulatedresponses;
<             }
<         } else {
<             $simulatedpostdata = null;
<         }
< 
<         $this->quba->process_all_actions($timestamp, $simulatedpostdata);
<         question_engine::save_questions_usage_by_activity($this->quba);
< 
<         $this->attempt->timemodified = $timestamp;
<         if ($this->attempt->state == self::FINISHED) {
<             $this->attempt->sumgrades = $this->quba->get_total_mark();
<         }
<         if ($becomingoverdue) {
<             $this->process_going_overdue($timestamp, true);
<         } else {
<             $DB->update_record('quiz_attempts', $this->attempt);
<         }
< 
<         if (!$this->is_preview() && $this->attempt->state == self::FINISHED) {
<             quiz_save_best_grade($this->get_quiz(), $this->get_userid());
<         }
< 
<         $transaction->allow_commit();
<     }
< 
<     /**
<      * Replace a question in an attempt with a new attempt at the same question.
<      *
<      * Well, for randomised questions, it won't be the same question, it will be
<      * a different randomised selection.
<      *
<      * @param int $slot the question to restart.
<      * @param int $timestamp the timestamp to record for this action.
<      */
<     public function process_redo_question($slot, $timestamp) {
<         global $DB;
< 
<         if (!$this->can_question_be_redone_now($slot)) {
<             throw new coding_exception('Attempt to restart the question in slot ' . $slot .
<                     ' when it is not in a state to be restarted.');
<         }
< 
<         $qubaids = new \mod_quiz\question\qubaids_for_users_attempts(
<                 $this->get_quizid(), $this->get_userid(), 'all', true);
< 
<         $transaction = $DB->start_delegated_transaction();
< 
<         // Choose the replacement question.
<         $questiondata = $DB->get_record('question',
<                 array('id' => $this->slots[$slot]->questionid));
<         if ($questiondata->qtype != 'random') {
<             $newqusetionid = $questiondata->id;
<         } else {
<             $tagids = quiz_retrieve_slot_tag_ids($this->slots[$slot]->id);
< 
<             $randomloader = new \core_question\bank\random_question_loader($qubaids, array());
<             $newqusetionid = $randomloader->get_next_question_id($questiondata->category,
<                     (bool) $questiondata->questiontext, $tagids);
<             if ($newqusetionid === null) {
<                 throw new moodle_exception('notenoughrandomquestions', 'quiz',
<                         $this->quizobj->view_url(), $questiondata);
<             }
<         }
< 
<         // Add the question to the usage. It is important we do this before we choose a variant.
<         $newquestion = question_bank::load_question($newqusetionid);
<         $newslot = $this->quba->add_question_in_place_of_other($slot, $newquestion);
< 
<         // Choose the variant.
<         if ($newquestion->get_num_variants() == 1) {
<             $variant = 1;
<         } else {
<             $variantstrategy = new core_question\engine\variants\least_used_strategy(
<                     $this->quba, $qubaids);
<             $variant = $variantstrategy->choose_variant($newquestion->get_num_variants(),
<                     $newquestion->get_variants_selection_seed());
<         }
< 
<         // Start the question.
<         $this->quba->start_question($slot, $variant);
<         $this->quba->set_max_mark($newslot, 0);
<         $this->quba->set_question_attempt_metadata($newslot, 'originalslot', $slot);
<         question_engine::save_questions_usage_by_activity($this->quba);
< 
<         $transaction->allow_commit();
<     }
< 
<     /**
<      * Process all the autosaved data that was part of the current request.
<      *
<      * @param int $timestamp the timestamp that should be stored as the modified.
<      * time in the database for these actions. If null, will use the current time.
<      */
<     public function process_auto_save($timestamp) {
<         global $DB;
< 
<         $transaction = $DB->start_delegated_transaction();
< 
<         $this->quba->process_all_autosaves($timestamp);
<         question_engine::save_questions_usage_by_activity($this->quba);
< 
<         $transaction->allow_commit();
<     }
< 
<     /**
<      * Update the flagged state for all question_attempts in this usage, if their
<      * flagged state was changed in the request.
<      */
<     public function save_question_flags() {
<         global $DB;
< 
<         $transaction = $DB->start_delegated_transaction();
<         $this->quba->update_question_flags();
<         question_engine::save_questions_usage_by_activity($this->quba);
<         $transaction->allow_commit();
<     }
< 
<     /**
<      * Submit the attempt.
<      *
<      * The separate $timefinish argument should be used when the quiz attempt
<      * is being processed asynchronously (for example when cron is submitting
<      * attempts where the time has expired).
<      *
<      * @param int $timestamp the time to record as last modified time.
<      * @param bool $processsubmitted if true, and question responses in the current
<      *      POST request are stored to be graded, before the attempt is finished.
<      * @param ?int $timefinish if set, use this as the finish time for the attempt.
<      *      (otherwise use $timestamp as the finish time as well).
<      */
<     public function process_finish($timestamp, $processsubmitted, $timefinish = null) {
<         global $DB;
< 
<         $transaction = $DB->start_delegated_transaction();
< 
<         if ($processsubmitted) {
<             $this->quba->process_all_actions($timestamp);
<         }
<         $this->quba->finish_all_questions($timestamp);
< 
<         question_engine::save_questions_usage_by_activity($this->quba);
< 
<         $this->attempt->timemodified = $timestamp;
<         $this->attempt->timefinish = $timefinish ?? $timestamp;
<         $this->attempt->sumgrades = $this->quba->get_total_mark();
<         $this->attempt->state = self::FINISHED;
<         $this->attempt->timecheckstate = null;
<         $DB->update_record('quiz_attempts', $this->attempt);
< 
<         if (!$this->is_preview()) {
<             quiz_save_best_grade($this->get_quiz(), $this->attempt->userid);
< 
<             // Trigger event.
<             $this->fire_state_transition_event('\mod_quiz\event\attempt_submitted', $timestamp);
< 
<             // Tell any access rules that care that the attempt is over.
<             $this->get_access_manager($timestamp)->current_attempt_finished();
<         }
< 
<         $transaction->allow_commit();
<     }
< 
<     /**
<      * Update this attempt timecheckstate if necessary.
<      *
<      * @param int|null $time the timestamp to set.
<      */
<     public function update_timecheckstate($time) {
<         global $DB;
<         if ($this->attempt->timecheckstate !== $time) {
<             $this->attempt->timecheckstate = $time;
<             $DB->set_field('quiz_attempts', 'timecheckstate', $time, array('id' => $this->attempt->id));
<         }
<     }
< 
<     /**
<      * Mark this attempt as now overdue.
<      *
<      * @param int $timestamp the time to deem as now.
<      * @param bool $studentisonline is the student currently interacting with Moodle?
<      */
<     public function process_going_overdue($timestamp, $studentisonline) {
<         global $DB;
< 
<         $transaction = $DB->start_delegated_transaction();
<         $this->attempt->timemodified = $timestamp;
<         $this->attempt->state = self::OVERDUE;
<         // If we knew the attempt close time, we could compute when the graceperiod ends.
<         // Instead we'll just fix it up through cron.
<         $this->attempt->timecheckstate = $timestamp;
<         $DB->update_record('quiz_attempts', $this->attempt);
< 
<         $this->fire_state_transition_event('\mod_quiz\event\attempt_becameoverdue', $timestamp);
< 
<         $transaction->allow_commit();
< 
<         quiz_send_overdue_message($this);
<     }
< 
<     /**
<      * Mark this attempt as abandoned.
<      *
<      * @param int $timestamp the time to deem as now.
<      * @param bool $studentisonline is the student currently interacting with Moodle?
<      */
<     public function process_abandon($timestamp, $studentisonline) {
<         global $DB;
< 
<         $transaction = $DB->start_delegated_transaction();
<         $this->attempt->timemodified = $timestamp;
<         $this->attempt->state = self::ABANDONED;
<         $this->attempt->timecheckstate = null;
<         $DB->update_record('quiz_attempts', $this->attempt);
< 
<         $this->fire_state_transition_event('\mod_quiz\event\attempt_abandoned', $timestamp);
< 
<         $transaction->allow_commit();
<     }
< 
<     /**
<      * Fire a state transition event.
<      *
<      * @param string $eventclass the event class name.
<      * @param int $timestamp the timestamp to include in the event.
<      */
<     protected function fire_state_transition_event($eventclass, $timestamp) {
<         global $USER;
<         $quizrecord = $this->get_quiz();
<         $params = array(
<             'context' => $this->get_quizobj()->get_context(),
<             'courseid' => $this->get_courseid(),
<             'objectid' => $this->attempt->id,
<             'relateduserid' => $this->attempt->userid,
<             'other' => array(
<                 'submitterid' => CLI_SCRIPT ? null : $USER->id,
<                 'quizid' => $quizrecord->id
<             )
<         );
< 
<         $event = $eventclass::create($params);
<         $event->add_record_snapshot('quiz', $this->get_quiz());
<         $event->add_record_snapshot('quiz_attempts', $this->get_attempt());
<         $event->trigger();
<     }
< 
<     // Private methods =========================================================
< 
<     /**
<      * Get a URL for a particular question on a particular page of the quiz.
<      * Used by {@link attempt_url()} and {@link review_url()}.
<      *
<      * @param string $script. Used in the URL like /mod/quiz/$script.php.
<      * @param int $slot identifies the specific question on the page to jump to.
<      *      0 to just use the $page parameter.
<      * @param int $page -1 to look up the page number from the slot, otherwise
<      *      the page number to go to.
<      * @param bool|null $showall if true, return a URL with showall=1, and not page number.
<      *      if null, then an intelligent default will be chosen.
<      * @param int $thispage the page we are currently on. Links to questions on this
<      *      page will just be a fragment #q123. -1 to disable this.
<      * @return moodle_url The requested URL.
<      */
<     protected function page_and_question_url($script, $slot, $page, $showall, $thispage) {
< 
<         $defaultshowall = $this->get_default_show_all($script);
<         if ($showall === null && ($page == 0 || $page == -1)) {
<             $showall = $defaultshowall;
<         }
< 
<         // Fix up $page.
<         if ($page == -1) {
<             if ($slot !== null && !$showall) {
<                 $page = $this->get_question_page($slot);
<             } else {
<                 $page = 0;
<             }
<         }
< 
<         if ($showall) {
<             $page = 0;
<         }
< 
<         // Add a fragment to scroll down to the question.
<         $fragment = '';
<         if ($slot !== null) {
<             if ($slot == reset($this->pagelayout[$page])) {
<                 // First question on page, go to top.
<                 $fragment = '#';
<             } else {
<                 $qa = $this->get_question_attempt($slot);
<                 $fragment = '#' . $qa->get_outer_question_div_unique_id();
<             }
<         }
< 
<         // Work out the correct start to the URL.
<         if ($thispage == $page) {
<             return new moodle_url($fragment);
< 
<         } else {
<             $url = new moodle_url('/mod/quiz/' . $script . '.php' . $fragment,
<                     array('attempt' => $this->attempt->id, 'cmid' => $this->get_cmid()));
<             if ($page == 0 && $showall != $defaultshowall) {
<                 $url->param('showall', (int) $showall);
<             } else if ($page > 0) {
<                 $url->param('page', $page);
<             }
<             return $url;
<         }
<     }
< 
<     /**
<      * Process responses during an attempt at a quiz.
<      *
<      * @param  int $timenow time when the processing started.
<      * @param  bool $finishattempt whether to finish the attempt or not.
<      * @param  bool $timeup true if form was submitted by timer.
<      * @param  int $thispage current page number.
<      * @return string the attempt state once the data has been processed.
<      * @since  Moodle 3.1
<      */
<     public function process_attempt($timenow, $finishattempt, $timeup, $thispage) {
<         global $DB;
< 
<         $transaction = $DB->start_delegated_transaction();
< 
<         // If there is only a very small amount of time left, there is no point trying
<         // to show the student another page of the quiz. Just finish now.
<         $graceperiodmin = null;
<         $accessmanager = $this->get_access_manager($timenow);
<         $timeclose = $accessmanager->get_end_time($this->get_attempt());
< 
<         // Don't enforce timeclose for previews.
<         if ($this->is_preview()) {
<             $timeclose = false;
<         }
<         $toolate = false;
<         if ($timeclose !== false && $timenow > $timeclose - QUIZ_MIN_TIME_TO_CONTINUE) {
<             $timeup = true;
<             $graceperiodmin = get_config('quiz', 'graceperiodmin');
<             if ($timenow > $timeclose + $graceperiodmin) {
<                 $toolate = true;
<             }
<         }
< 
<         // If time is running out, trigger the appropriate action.
<         $becomingoverdue = false;
<         $becomingabandoned = false;
<         if ($timeup) {
<             if ($this->get_quiz()->overduehandling == 'graceperiod') {
<                 if (is_null($graceperiodmin)) {
<                     $graceperiodmin = get_config('quiz', 'graceperiodmin');
<                 }
<                 if ($timenow > $timeclose + $this->get_quiz()->graceperiod + $graceperiodmin) {
<                     // Grace period has run out.
<                     $finishattempt = true;
<                     $becomingabandoned = true;
<                 } else {
<                     $becomingoverdue = true;
<                 }
<             } else {
<                 $finishattempt = true;
<             }
<         }
< 
<         // Don't log - we will end with a redirect to a page that is logged.
< 
<         if (!$finishattempt) {
<             // Just process the responses for this page and go to the next page.
<             if (!$toolate) {
<                 try {
<                     $this->process_submitted_actions($timenow, $becomingoverdue);
< 
<                 } catch (question_out_of_sequence_exception $e) {
<                     throw new moodle_exception('submissionoutofsequencefriendlymessage', 'question',
<                             $this->attempt_url(null, $thispage));
< 
<                 } catch (Exception $e) {
<                     // This sucks, if we display our own custom error message, there is no way
<                     // to display the original stack trace.
<                     $debuginfo = '';
<                     if (!empty($e->debuginfo)) {
<                         $debuginfo = $e->debuginfo;
<                     }
<                     throw new moodle_exception('errorprocessingresponses', 'question',
<                             $this->attempt_url(null, $thispage), $e->getMessage(), $debuginfo);
<                 }
< 
<                 if (!$becomingoverdue) {
<                     foreach ($this->get_slots() as $slot) {
<                         if (optional_param('redoslot' . $slot, false, PARAM_BOOL)) {
<                             $this->process_redo_question($slot, $timenow);
<                         }
<                     }
<                 }
< 
<             } else {
<                 // The student is too late.
<                 $this->process_going_overdue($timenow, true);
<             }
< 
<             $transaction->allow_commit();
< 
<             return $becomingoverdue ? self::OVERDUE : self::IN_PROGRESS;
<         }
< 
<         // Update the quiz attempt record.
<         try {
<             if ($becomingabandoned) {
<                 $this->process_abandon($timenow, true);
<             } else {
<                 $this->process_finish($timenow, !$toolate, $toolate ? $timeclose : $timenow);
<             }
< 
<         } catch (question_out_of_sequence_exception $e) {
<             throw new moodle_exception('submissionoutofsequencefriendlymessage', 'question',
<                     $this->attempt_url(null, $thispage));
< 
<         } catch (Exception $e) {
<             // This sucks, if we display our own custom error message, there is no way
<             // to display the original stack trace.
<             $debuginfo = '';
<             if (!empty($e->debuginfo)) {
<                 $debuginfo = $e->debuginfo;
<             }
<             throw new moodle_exception('errorprocessingresponses', 'question',
<                     $this->attempt_url(null, $thispage), $e->getMessage(), $debuginfo);
<         }
< 
<         // Send the user to the review page.
<         $transaction->allow_commit();
< 
<         return $becomingabandoned ? self::ABANDONED : self::FINISHED;
<     }
< 
<     /**
<      * Check a page access to see if is an out of sequence access.
<      *
<      * @param  int $page page number.
<      * @return boolean false is is an out of sequence access, true otherwise.
<      * @since Moodle 3.1
<      */
<     public function check_page_access($page) {
<         if ($this->get_currentpage() != $page) {
<             if ($this->get_navigation_method() == QUIZ_NAVMETHOD_SEQ && $this->get_currentpage() > $page) {
<                 return false;
<             }
<         }
<         return true;
<     }
< 
<     /**
<      * Update attempt page.
<      *
<      * @param  int $page page number.
<      * @return boolean true if everything was ok, false otherwise (out of sequence access).
<      * @since Moodle 3.1
<      */
<     public function set_currentpage($page) {
<         global $DB;
< 
<         if ($this->check_page_access($page)) {
<             $DB->set_field('quiz_attempts', 'currentpage', $page, array('id' => $this->get_attemptid()));
<             return true;
<         }
<         return false;
<     }
< 
<     /**
<      * Trigger the attempt_viewed event.
<      *
<      * @since Moodle 3.1
<      */
<     public function fire_attempt_viewed_event() {
<         $params = array(
<             'objectid' => $this->get_attemptid(),
<             'relateduserid' => $this->get_userid(),
<             'courseid' => $this->get_courseid(),
<             'context' => context_module::instance($this->get_cmid()),
<             'other' => array(
<                 'quizid' => $this->get_quizid()
<             )
<         );
<         $event = \mod_quiz\event\attempt_viewed::create($params);
<         $event->add_record_snapshot('quiz_attempts', $this->get_attempt());
<         $event->trigger();
<     }
< 
<     /**
<      * Trigger the attempt_summary_viewed event.
<      *
<      * @since Moodle 3.1
<      */
<     public function fire_attempt_summary_viewed_event() {
< 
<         $params = array(
<             'objectid' => $this->get_attemptid(),
<             'relateduserid' => $this->get_userid(),
<             'courseid' => $this->get_courseid(),
<             'context' => context_module::instance($this->get_cmid()),
<             'other' => array(
<                 'quizid' => $this->get_quizid()
<             )
<         );
<         $event = \mod_quiz\event\attempt_summary_viewed::create($params);
<         $event->add_record_snapshot('quiz_attempts', $this->get_attempt());
<         $event->trigger();
<     }
< 
<     /**
<      * Trigger the attempt_reviewed event.
<      *
<      * @since Moodle 3.1
<      */
<     public function fire_attempt_reviewed_event() {
< 
<         $params = array(
<             'objectid' => $this->get_attemptid(),
<             'relateduserid' => $this->get_userid(),
<             'courseid' => $this->get_courseid(),
<             'context' => context_module::instance($this->get_cmid()),
<             'other' => array(
<                 'quizid' => $this->get_quizid()
<             )
<         );
<         $event = \mod_quiz\event\attempt_reviewed::create($params);
<         $event->add_record_snapshot('quiz_attempts', $this->get_attempt());
<         $event->trigger();
<     }
< 
<     /**
<      * Update the timemodifiedoffline attempt field.
<      *
<      * This function should be used only when web services are being used.
<      *
<      * @param int $time time stamp.
<      * @return boolean false if the field is not updated because web services aren't being used.
<      * @since Moodle 3.2
<      */
<     public function set_offline_modified_time($time) {
<         // Update the timemodifiedoffline field only if web services are being used.
<         if (WS_SERVER) {
<             $this->attempt->timemodifiedoffline = $time;
<             return true;
<         }
<         return false;
<     }
< 
< }
< 
< 
< /**
<  * Represents a heading in the navigation panel.
<  *
<  * @copyright  2015 The Open University
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since      Moodle 2.9
<  */
< class quiz_nav_section_heading implements renderable {
<     /** @var string the heading text. */
<     public $heading;
< 
<     /**
<      * Constructor.
<      * @param string $heading the heading text
<      */
<     public function __construct($heading) {
<         $this->heading = $heading;
<     }
< }
< 
< 
< /**
<  * Represents a single link in the navigation panel.
<  *
<  * @copyright  2011 The Open University
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since      Moodle 2.1
<  */
< class quiz_nav_question_button implements renderable {
<     /** @var string id="..." to add to the HTML for this button. */
<     public $id;
<     /** @var string number to display in this button. Either the question number of 'i'. */
<     public $number;
<     /** @var string class to add to the class="" attribute to represnt the question state. */
<     public $stateclass;
<     /** @var string Textual description of the question state, e.g. to use as a tool tip. */
<     public $statestring;
<     /** @var int the page number this question is on. */
<     public $page;
<     /** @var bool true if this question is on the current page. */
<     public $currentpage;
<     /** @var bool true if this question has been flagged. */
<     public $flagged;
<     /** @var moodle_url the link this button goes to, or null if there should not be a link. */
<     public $url;
<     /** @var int QUIZ_NAVMETHOD_FREE or QUIZ_NAVMETHOD_SEQ. */
<     public $navmethod;
< }
< 
< 
< /**
<  * Represents the navigation panel, and builds a {@link block_contents} to allow
<  * it to be output.
<  *
<  * @copyright  2008 Tim Hunt
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since      Moodle 2.0
<  */
< abstract class quiz_nav_panel_base {
<     /** @var quiz_attempt */
<     protected $attemptobj;
<     /** @var question_display_options */
<     protected $options;
<     /** @var integer */
<     protected $page;
<     /** @var boolean */
<     protected $showall;
< 
<     public function __construct(quiz_attempt $attemptobj,
<             question_display_options $options, $page, $showall) {
<         $this->attemptobj = $attemptobj;
<         $this->options = $options;
<         $this->page = $page;
<         $this->showall = $showall;
<     }
< 
<     /**
<      * Get the buttons and section headings to go in the quiz navigation block.
<      *
<      * @return renderable[] the buttons, possibly interleaved with section headings.
<      */
<     public function get_question_buttons() {
<         $buttons = array();
<         foreach ($this->attemptobj->get_slots() as $slot) {
<             $heading = $this->attemptobj->get_heading_before_slot($slot);
<             if (!is_null($heading)) {
<                 $sections = $this->attemptobj->get_quizobj()->get_sections();
<                 if (!(empty($heading) && count($sections) == 1)) {
<                     $buttons[] = new quiz_nav_section_heading(format_string($heading));
<                 }
<             }
< 
<             $qa = $this->attemptobj->get_question_attempt($slot);
<             $showcorrectness = $this->options->correctness && $qa->has_marks();
< 
<             $button = new quiz_nav_question_button();
<             $button->id          = 'quiznavbutton' . $slot;
<             $button->number      = $this->attemptobj->get_question_number($slot);
<             $button->stateclass  = $qa->get_state_class($showcorrectness);
<             $button->navmethod   = $this->attemptobj->get_navigation_method();
<             if (!$showcorrectness && $button->stateclass == 'notanswered') {
<                 $button->stateclass = 'complete';
<             }
<             $button->statestring = $this->get_state_string($qa, $showcorrectness);
<             $button->page        = $this->attemptobj->get_question_page($slot);
<             $button->currentpage = $this->showall || $button->page == $this->page;
<             $button->flagged     = $qa->is_flagged();
<             $button->url         = $this->get_question_url($slot);
<             if ($this->attemptobj->is_blocked_by_previous_question($slot)) {
<                 $button->url = null;
<                 $button->stateclass = 'blocked';
<                 $button->statestring = get_string('questiondependsonprevious', 'quiz');
<             }
<             $buttons[] = $button;
<         }
< 
<         return $buttons;
<     }
< 
<     protected function get_state_string(question_attempt $qa, $showcorrectness) {
<         if ($qa->get_question(false)->length > 0) {
<             return $qa->get_state_string($showcorrectness);
<         }
< 
<         // Special case handling for 'information' items.
<         if ($qa->get_state() == question_state::$todo) {
<             return get_string('notyetviewed', 'quiz');
<         } else {
<             return get_string('viewed', 'quiz');
<         }
<     }
< 
<     /**
<      * Hook for subclasses to override.
<      *
<      * @param mod_quiz_renderer $output the quiz renderer to use.
<      * @return string HTML to output.
<      */
<     public function render_before_button_bits(mod_quiz_renderer $output) {
<         return '';
<     }
< 
<     abstract public function render_end_bits(mod_quiz_renderer $output);
< 
<     /**
<      * Render the restart preview button.
<      *
<      * @param mod_quiz_renderer $output the quiz renderer to use.
<      * @return string HTML to output.
<      */
<     protected function render_restart_preview_link($output) {
<         if (!$this->attemptobj->is_own_preview()) {
<             return '';
<         }
<         return $output->restart_preview_button(new moodle_url(
<                 $this->attemptobj->start_attempt_url(), array('forcenew' => true)));
<     }
< 
<     protected abstract function get_question_url($slot);
< 
<     public function user_picture() {
<         global $DB;
<         if ($this->attemptobj->get_quiz()->showuserpicture == QUIZ_SHOWIMAGE_NONE) {
<             return null;
<         }
<         $user = $DB->get_record('user', array('id' => $this->attemptobj->get_userid()));
<         $userpicture = new user_picture($user);
<         $userpicture->courseid = $this->attemptobj->get_courseid();
<         if ($this->attemptobj->get_quiz()->showuserpicture == QUIZ_SHOWIMAGE_LARGE) {
<             $userpicture->size = true;
<         }
<         return $userpicture;
<     }
< 
<     /**
<      * Return 'allquestionsononepage' as CSS class name when $showall is set,
<      * otherwise, return 'multipages' as CSS class name.
<      *
<      * @return string, CSS class name
<      */
<     public function get_button_container_class() {
<         // Quiz navigation is set on 'Show all questions on one page'.
<         if ($this->showall) {
<             return 'allquestionsononepage';
<         }
<         // Quiz navigation is set on 'Show one page at a time'.
<         return 'multipages';
<     }
< }
< 
< 
< /**
<  * Specialisation of {@link quiz_nav_panel_base} for the attempt quiz page.
<  *
<  * @copyright  2008 Tim Hunt
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since      Moodle 2.0
<  */
< class quiz_attempt_nav_panel extends quiz_nav_panel_base {
<     public function get_question_url($slot) {
<         if ($this->attemptobj->can_navigate_to($slot)) {
<             return $this->attemptobj->attempt_url($slot, -1, $this->page);
<         } else {
<             return null;
<         }
<     }
< 
<     public function render_before_button_bits(mod_quiz_renderer $output) {
<         return html_writer::tag('div', get_string('navnojswarning', 'quiz'),
<                 array('id' => 'quiznojswarning'));
<     }
< 
<     public function render_end_bits(mod_quiz_renderer $output) {
<         if ($this->page == -1) {
<             // Don't link from the summary page to itself.
<             return '';
<         }
<         return html_writer::link($this->attemptobj->summary_url(),
<                 get_string('endtest', 'quiz'), array('class' => 'endtestlink aalink')) .
<                 $this->render_restart_preview_link($output);
<     }
< }
< 
< 
< /**
<  * Specialisation of {@link quiz_nav_panel_base} for the review quiz page.
<  *
<  * @copyright  2008 Tim Hunt
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since      Moodle 2.0
<  */
< class quiz_review_nav_panel extends quiz_nav_panel_base {
<     public function get_question_url($slot) {
<         return $this->attemptobj->review_url($slot, -1, $this->showall, $this->page);
<     }



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




<     public function render_end_bits(mod_quiz_renderer $output) {
<         $html = '';
<         if ($this->attemptobj->get_num_pages() > 1) {
<             if ($this->showall) {
<                 $html .= html_writer::link($this->attemptobj->review_url(null, 0, false),
<                         get_string('showeachpage', 'quiz'));
<             } else {
<                 $html .= html_writer::link($this->attemptobj->review_url(null, 0, true),
<                         get_string('showall', 'quiz'));
<             }
<         }
<         $html .= $output->finish_review_link($this->attemptobj);
<         $html .= $this->render_restart_preview_link($output);
<         return $html;
<     }
< }



> debugging('This file is no longer required in Moodle 4.2+. Please do not include/require it.', DEBUG_DEVELOPER);