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Differences Between: [Versions 310 and 311] [Versions 310 and 400] [Versions 310 and 401] [Versions 310 and 402] [Versions 310 and 403] [Versions 39 and 310]

   1  <?php
   2  // This file is part of Moodle - http://moodle.org/
   3  //
   4  // Moodle is free software: you can redistribute it and/or modify
   5  // it under the terms of the GNU General Public License as published by
   6  // the Free Software Foundation, either version 3 of the License, or
   7  // (at your option) any later version.
   8  //
   9  // Moodle is distributed in the hope that it will be useful,
  10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  // GNU General Public License for more details.
  13  //
  14  // You should have received a copy of the GNU General Public License
  15  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16  
  17  /**
  18   * Back-end code for handling data about quizzes and the current user's attempt.
  19   *
  20   * There are classes for loading all the information about a quiz and attempts,
  21   * and for displaying the navigation panel.
  22   *
  23   * @package   mod_quiz
  24   * @copyright 2008 onwards Tim Hunt
  25   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26   */
  27  
  28  
  29  defined('MOODLE_INTERNAL') || die();
  30  
  31  
  32  /**
  33   * Class for quiz exceptions. Just saves a couple of arguments on the
  34   * constructor for a moodle_exception.
  35   *
  36   * @copyright 2008 Tim Hunt
  37   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  38   * @since     Moodle 2.0
  39   */
  40  class moodle_quiz_exception extends moodle_exception {
  41      /**
  42       * Constructor.
  43       *
  44       * @param quiz $quizobj the quiz the error relates to.
  45       * @param string $errorcode The name of the string from error.php to print.
  46       * @param mixed $a Extra words and phrases that might be required in the error string.
  47       * @param string $link The url where the user will be prompted to continue.
  48       *      If no url is provided the user will be directed to the site index page.
  49       * @param string|null $debuginfo optional debugging information.
  50       */
  51      public function __construct($quizobj, $errorcode, $a = null, $link = '', $debuginfo = null) {
  52          if (!$link) {
  53              $link = $quizobj->view_url();
  54          }
  55          parent::__construct($errorcode, 'quiz', $link, $a, $debuginfo);
  56      }
  57  }
  58  
  59  
  60  /**
  61   * A class encapsulating a quiz and the questions it contains, and making the
  62   * information available to scripts like view.php.
  63   *
  64   * Initially, it only loads a minimal amout of information about each question - loading
  65   * extra information only when necessary or when asked. The class tracks which questions
  66   * are loaded.
  67   *
  68   * @copyright  2008 Tim Hunt
  69   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  70   * @since      Moodle 2.0
  71   */
  72  class quiz {
  73      /** @var stdClass the course settings from the database. */
  74      protected $course;
  75      /** @var stdClass the course_module settings from the database. */
  76      protected $cm;
  77      /** @var stdClass the quiz settings from the database. */
  78      protected $quiz;
  79      /** @var context the quiz context. */
  80      protected $context;
  81  
  82      /** @var stdClass[] of questions augmented with slot information. */
  83      protected $questions = null;
  84      /** @var stdClass[] of quiz_section rows. */
  85      protected $sections = null;
  86      /** @var quiz_access_manager the access manager for this quiz. */
  87      protected $accessmanager = null;
  88      /** @var bool whether the current user has capability mod/quiz:preview. */
  89      protected $ispreviewuser = null;
  90  
  91      // Constructor =============================================================
  92      /**
  93       * Constructor, assuming we already have the necessary data loaded.
  94       *
  95       * @param object $quiz the row from the quiz table.
  96       * @param object $cm the course_module object for this quiz.
  97       * @param object $course the row from the course table for the course we belong to.
  98       * @param bool $getcontext intended for testing - stops the constructor getting the context.
  99       */
 100      public function __construct($quiz, $cm, $course, $getcontext = true) {
 101          $this->quiz = $quiz;
 102          $this->cm = $cm;
 103          $this->quiz->cmid = $this->cm->id;
 104          $this->course = $course;
 105          if ($getcontext && !empty($cm->id)) {
 106              $this->context = context_module::instance($cm->id);
 107          }
 108      }
 109  
 110      /**
 111       * Static function to create a new quiz object for a specific user.
 112       *
 113       * @param int $quizid the the quiz id.
 114       * @param int|null $userid the the userid (optional). If passed, relevant overrides are applied.
 115       * @return quiz the new quiz object.
 116       */
 117      public static function create($quizid, $userid = null) {
 118          global $DB;
 119  
 120          $quiz = quiz_access_manager::load_quiz_and_settings($quizid);
 121          $course = $DB->get_record('course', array('id' => $quiz->course), '*', MUST_EXIST);
 122          $cm = get_coursemodule_from_instance('quiz', $quiz->id, $course->id, false, MUST_EXIST);
 123  
 124          // Update quiz with override information.
 125          if ($userid) {
 126              $quiz = quiz_update_effective_access($quiz, $userid);
 127          }
 128  
 129          return new quiz($quiz, $cm, $course);
 130      }
 131  
 132      /**
 133       * Create a {@link quiz_attempt} for an attempt at this quiz.
 134       *
 135       * @param object $attemptdata row from the quiz_attempts table.
 136       * @return quiz_attempt the new quiz_attempt object.
 137       */
 138      public function create_attempt_object($attemptdata) {
 139          return new quiz_attempt($attemptdata, $this->quiz, $this->cm, $this->course);
 140      }
 141  
 142      // Functions for loading more data =========================================
 143  
 144      /**
 145       * Load just basic information about all the questions in this quiz.
 146       */
 147      public function preload_questions() {
 148          $this->questions = question_preload_questions(null,
 149                  'slot.maxmark, slot.id AS slotid, slot.slot, slot.page,
 150                   slot.questioncategoryid AS randomfromcategory,
 151                   slot.includingsubcategories AS randomincludingsubcategories',
 152                  '{quiz_slots} slot ON slot.quizid = :quizid AND q.id = slot.questionid',
 153                  array('quizid' => $this->quiz->id), 'slot.slot');
 154      }
 155  
 156      /**
 157       * Fully load some or all of the questions for this quiz. You must call
 158       * {@link preload_questions()} first.
 159       *
 160       * @param array|null $questionids question ids of the questions to load. null for all.
 161       */
 162      public function load_questions($questionids = null) {
 163          if ($this->questions === null) {
 164              throw new coding_exception('You must call preload_questions before calling load_questions.');
 165          }
 166          if (is_null($questionids)) {
 167              $questionids = array_keys($this->questions);
 168          }
 169          $questionstoprocess = array();
 170          foreach ($questionids as $id) {
 171              if (array_key_exists($id, $this->questions)) {
 172                  $questionstoprocess[$id] = $this->questions[$id];
 173              }
 174          }
 175          get_question_options($questionstoprocess);
 176      }
 177  
 178      /**
 179       * Get an instance of the {@link \mod_quiz\structure} class for this quiz.
 180       * @return \mod_quiz\structure describes the questions in the quiz.
 181       */
 182      public function get_structure() {
 183          return \mod_quiz\structure::create_for_quiz($this);
 184      }
 185  
 186      // Simple getters ==========================================================
 187      /**
 188       * Get the id of the course this quiz belongs to.
 189       *
 190       * @return int the course id.
 191       */
 192      public function get_courseid() {
 193          return $this->course->id;
 194      }
 195  
 196      /**
 197       * Get the course settings object that this quiz belongs to.
 198       *
 199       * @return object the row of the course table.
 200       */
 201      public function get_course() {
 202          return $this->course;
 203      }
 204  
 205      /**
 206       * Get this quiz's id (in the quiz table).
 207       *
 208       * @return int the quiz id.
 209       */
 210      public function get_quizid() {
 211          return $this->quiz->id;
 212      }
 213  
 214      /**
 215       * Get the quiz settings object.
 216       *
 217       * @return stdClass the row of the quiz table.
 218       */
 219      public function get_quiz() {
 220          return $this->quiz;
 221      }
 222  
 223      /**
 224       * Get the quiz name.
 225       *
 226       * @return string the name of this quiz.
 227       */
 228      public function get_quiz_name() {
 229          return $this->quiz->name;
 230      }
 231  
 232      /**
 233       * Get the navigation method in use.
 234       *
 235       * @return int QUIZ_NAVMETHOD_FREE or QUIZ_NAVMETHOD_SEQ.
 236       */
 237      public function get_navigation_method() {
 238          return $this->quiz->navmethod;
 239      }
 240  
 241      /** @return int the number of attempts allowed at this quiz (0 = infinite). */
 242      public function get_num_attempts_allowed() {
 243          return $this->quiz->attempts;
 244      }
 245  
 246      /**
 247       * Get the course-module id for this quiz.
 248       *
 249       * @return int the course_module id.
 250       */
 251      public function get_cmid() {
 252          return $this->cm->id;
 253      }
 254  
 255      /**
 256       * Get the course-module object for this quiz.
 257       *
 258       * @return object the course_module object.
 259       */
 260      public function get_cm() {
 261          return $this->cm;
 262      }
 263  
 264      /**
 265       * Get the quiz context.
 266       *
 267       * @return context the module context for this quiz.
 268       */
 269      public function get_context() {
 270          return $this->context;
 271      }
 272  
 273      /**
 274       * @return bool wether the current user is someone who previews the quiz,
 275       * rather than attempting it.
 276       */
 277      public function is_preview_user() {
 278          if (is_null($this->ispreviewuser)) {
 279              $this->ispreviewuser = has_capability('mod/quiz:preview', $this->context);
 280          }
 281          return $this->ispreviewuser;
 282      }
 283  
 284      /**
 285       * Checks user enrollment in the current course.
 286       *
 287       * @param int $userid the id of the user to check.
 288       * @return bool whether the user is enrolled.
 289       */
 290      public function is_participant($userid) {
 291          return is_enrolled($this->get_context(), $userid, 'mod/quiz:attempt', $this->show_only_active_users());
 292      }
 293  
 294      /**
 295       * Check is only active users in course should be shown.
 296       *
 297       * @return bool true if only active users should be shown.
 298       */
 299      public function show_only_active_users() {
 300          return !has_capability('moodle/course:viewsuspendedusers', $this->get_context());
 301      }
 302  
 303      /**
 304       * @return bool whether any questions have been added to this quiz.
 305       */
 306      public function has_questions() {
 307          if ($this->questions === null) {
 308              $this->preload_questions();
 309          }
 310          return !empty($this->questions);
 311      }
 312  
 313      /**
 314       * @param int $id the question id.
 315       * @return stdClass the question object with that id.
 316       */
 317      public function get_question($id) {
 318          return $this->questions[$id];
 319      }
 320  
 321      /**
 322       * @param array|null $questionids question ids of the questions to load. null for all.
 323       * @return stdClass[] the question data objects.
 324       */
 325      public function get_questions($questionids = null) {
 326          if (is_null($questionids)) {
 327              $questionids = array_keys($this->questions);
 328          }
 329          $questions = array();
 330          foreach ($questionids as $id) {
 331              if (!array_key_exists($id, $this->questions)) {
 332                  throw new moodle_exception('cannotstartmissingquestion', 'quiz', $this->view_url());
 333              }
 334              $questions[$id] = $this->questions[$id];
 335              $this->ensure_question_loaded($id);
 336          }
 337          return $questions;
 338      }
 339  
 340      /**
 341       * Get all the sections in this quiz.
 342       *
 343       * @return array 0, 1, 2, ... => quiz_sections row from the database.
 344       */
 345      public function get_sections() {
 346          global $DB;
 347          if ($this->sections === null) {
 348              $this->sections = array_values($DB->get_records('quiz_sections',
 349                      array('quizid' => $this->get_quizid()), 'firstslot'));
 350          }
 351          return $this->sections;
 352      }
 353  
 354      /**
 355       * Return quiz_access_manager and instance of the quiz_access_manager class
 356       * for this quiz at this time.
 357       *
 358       * @param int $timenow the current time as a unix timestamp.
 359       * @return quiz_access_manager and instance of the quiz_access_manager class
 360       *      for this quiz at this time.
 361       */
 362      public function get_access_manager($timenow) {
 363          if (is_null($this->accessmanager)) {
 364              $this->accessmanager = new quiz_access_manager($this, $timenow,
 365                      has_capability('mod/quiz:ignoretimelimits', $this->context, null, false));
 366          }
 367          return $this->accessmanager;
 368      }
 369  
 370      /**
 371       * Wrapper round the has_capability funciton that automatically passes in the quiz context.
 372       *
 373       * @param string $capability the name of the capability to check. For example mod/quiz:view.
 374       * @param int|null $userid A user id. By default (null) checks the permissions of the current user.
 375       * @param bool $doanything If false, ignore effect of admin role assignment.
 376       * @return boolean true if the user has this capability. Otherwise false.
 377       */
 378      public function has_capability($capability, $userid = null, $doanything = true) {
 379          return has_capability($capability, $this->context, $userid, $doanything);
 380      }
 381  
 382      /**
 383       * Wrapper round the require_capability function that automatically passes in the quiz context.
 384       *
 385       * @param string $capability the name of the capability to check. For example mod/quiz:view.
 386       * @param int|null $userid A user id. By default (null) checks the permissions of the current user.
 387       * @param bool $doanything If false, ignore effect of admin role assignment.
 388       */
 389      public function require_capability($capability, $userid = null, $doanything = true) {
 390          require_capability($capability, $this->context, $userid, $doanything);
 391      }
 392  
 393      // URLs related to this attempt ============================================
 394      /**
 395       * @return string the URL of this quiz's view page.
 396       */
 397      public function view_url() {
 398          global $CFG;
 399          return $CFG->wwwroot . '/mod/quiz/view.php?id=' . $this->cm->id;
 400      }
 401  
 402      /**
 403       * @return string the URL of this quiz's edit page.
 404       */
 405      public function edit_url() {
 406          global $CFG;
 407          return $CFG->wwwroot . '/mod/quiz/edit.php?cmid=' . $this->cm->id;
 408      }
 409  
 410      /**
 411       * @param int $attemptid the id of an attempt.
 412       * @param int $page optional page number to go to in the attempt.
 413       * @return string the URL of that attempt.
 414       */
 415      public function attempt_url($attemptid, $page = 0) {
 416          global $CFG;
 417          $url = $CFG->wwwroot . '/mod/quiz/attempt.php?attempt=' . $attemptid;
 418          if ($page) {
 419              $url .= '&page=' . $page;
 420          }
 421          $url .= '&cmid=' . $this->get_cmid();
 422          return $url;
 423      }
 424  
 425      /**
 426       * Get the URL to start/continue an attempt.
 427       *
 428       * @param int $page page in the attempt to start on (optional).
 429       * @return moodle_url the URL of this quiz's edit page. Needs to be POSTed to with a cmid parameter.
 430       */
 431      public function start_attempt_url($page = 0) {
 432          $params = array('cmid' => $this->cm->id, 'sesskey' => sesskey());
 433          if ($page) {
 434              $params['page'] = $page;
 435          }
 436          return new moodle_url('/mod/quiz/startattempt.php', $params);
 437      }
 438  
 439      /**
 440       * @param int $attemptid the id of an attempt.
 441       * @return string the URL of the review of that attempt.
 442       */
 443      public function review_url($attemptid) {
 444          return new moodle_url('/mod/quiz/review.php', array('attempt' => $attemptid, 'cmid' => $this->get_cmid()));
 445      }
 446  
 447      /**
 448       * @param int $attemptid the id of an attempt.
 449       * @return string the URL of the review of that attempt.
 450       */
 451      public function summary_url($attemptid) {
 452          return new moodle_url('/mod/quiz/summary.php', array('attempt' => $attemptid, 'cmid' => $this->get_cmid()));
 453      }
 454  
 455      // Bits of content =========================================================
 456  
 457      /**
 458       * @param bool $notused not used.
 459       * @return string an empty string.
 460       * @deprecated since 3.1. This sort of functionality is now entirely handled by quiz access rules.
 461       */
 462      public function confirm_start_attempt_message($notused) {
 463          debugging('confirm_start_attempt_message is deprecated. ' .
 464                  'This sort of functionality is now entirely handled by quiz access rules.');
 465          return '';
 466      }
 467  
 468      /**
 469       * If $reviewoptions->attempt is false, meaning that students can't review this
 470       * attempt at the moment, return an appropriate string explaining why.
 471       *
 472       * @param int $when One of the mod_quiz_display_options::DURING,
 473       *      IMMEDIATELY_AFTER, LATER_WHILE_OPEN or AFTER_CLOSE constants.
 474       * @param bool $short if true, return a shorter string.
 475       * @return string an appropraite message.
 476       */
 477      public function cannot_review_message($when, $short = false) {
 478  
 479          if ($short) {
 480              $langstrsuffix = 'short';
 481              $dateformat = get_string('strftimedatetimeshort', 'langconfig');
 482          } else {
 483              $langstrsuffix = '';
 484              $dateformat = '';
 485          }
 486  
 487          if ($when == mod_quiz_display_options::DURING ||
 488                  $when == mod_quiz_display_options::IMMEDIATELY_AFTER) {
 489              return '';
 490          } else if ($when == mod_quiz_display_options::LATER_WHILE_OPEN && $this->quiz->timeclose &&
 491                  $this->quiz->reviewattempt & mod_quiz_display_options::AFTER_CLOSE) {
 492              return get_string('noreviewuntil' . $langstrsuffix, 'quiz',
 493                      userdate($this->quiz->timeclose, $dateformat));
 494          } else {
 495              return get_string('noreview' . $langstrsuffix, 'quiz');
 496          }
 497      }
 498  
 499      /**
 500       * Probably not used any more, but left for backwards compatibility.
 501       *
 502       * @param string $title the name of this particular quiz page.
 503       * @return string always returns ''.
 504       */
 505      public function navigation($title) {
 506          global $PAGE;
 507          $PAGE->navbar->add($title);
 508          return '';
 509      }
 510  
 511      // Private methods =========================================================
 512      /**
 513       * Check that the definition of a particular question is loaded, and if not throw an exception.
 514       *
 515       * @param int $id a question id.
 516       */
 517      protected function ensure_question_loaded($id) {
 518          if (isset($this->questions[$id]->_partiallyloaded)) {
 519              throw new moodle_quiz_exception($this, 'questionnotloaded', $id);
 520          }
 521      }
 522  
 523      /**
 524       * Return all the question types used in this quiz.
 525       *
 526       * @param  boolean $includepotential if the quiz include random questions,
 527       *      setting this flag to true will make the function to return all the
 528       *      possible question types in the random questions category.
 529       * @return array a sorted array including the different question types.
 530       * @since  Moodle 3.1
 531       */
 532      public function get_all_question_types_used($includepotential = false) {
 533          $questiontypes = array();
 534  
 535          // To control if we need to look in categories for questions.
 536          $qcategories = array();
 537  
 538          // We must be careful with random questions, if we find a random question we must assume that the quiz may content
 539          // any of the questions in the referenced category (or subcategories).
 540          foreach ($this->get_questions() as $questiondata) {
 541              if ($questiondata->qtype == 'random' and $includepotential) {
 542                  $includesubcategories = (bool) $questiondata->questiontext;
 543                  if (!isset($qcategories[$questiondata->category])) {
 544                      $qcategories[$questiondata->category] = false;
 545                  }
 546                  if ($includesubcategories) {
 547                      $qcategories[$questiondata->category] = true;
 548                  }
 549              } else {
 550                  if (!in_array($questiondata->qtype, $questiontypes)) {
 551                      $questiontypes[] = $questiondata->qtype;
 552                  }
 553              }
 554          }
 555  
 556          if (!empty($qcategories)) {
 557              // We have to look for all the question types in these categories.
 558              $categoriestolook = array();
 559              foreach ($qcategories as $cat => $includesubcats) {
 560                  if ($includesubcats) {
 561                      $categoriestolook = array_merge($categoriestolook, question_categorylist($cat));
 562                  } else {
 563                      $categoriestolook[] = $cat;
 564                  }
 565              }
 566              $questiontypesincategories = question_bank::get_all_question_types_in_categories($categoriestolook);
 567              $questiontypes = array_merge($questiontypes, $questiontypesincategories);
 568          }
 569          $questiontypes = array_unique($questiontypes);
 570          sort($questiontypes);
 571  
 572          return $questiontypes;
 573      }
 574  }
 575  
 576  
 577  /**
 578   * This class extends the quiz class to hold data about the state of a particular attempt,
 579   * in addition to the data about the quiz.
 580   *
 581   * @copyright  2008 Tim Hunt
 582   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 583   * @since      Moodle 2.0
 584   */
 585  class quiz_attempt {
 586  
 587      /** @var string to identify the in progress state. */
 588      const IN_PROGRESS = 'inprogress';
 589      /** @var string to identify the overdue state. */
 590      const OVERDUE     = 'overdue';
 591      /** @var string to identify the finished state. */
 592      const FINISHED    = 'finished';
 593      /** @var string to identify the abandoned state. */
 594      const ABANDONED   = 'abandoned';
 595  
 596      /** @var int maximum number of slots in the quiz for the review page to default to show all. */
 597      const MAX_SLOTS_FOR_DEFAULT_REVIEW_SHOW_ALL = 50;
 598  
 599      /** @var quiz object containing the quiz settings. */
 600      protected $quizobj;
 601  
 602      /** @var stdClass the quiz_attempts row. */
 603      protected $attempt;
 604  
 605      /** @var question_usage_by_activity the question usage for this quiz attempt. */
 606      protected $quba;
 607  
 608      /**
 609       * @var array of slot information. These objects contain ->slot (int),
 610       *      ->requireprevious (bool), ->questionids (int) the original question for random questions,
 611       *      ->firstinsection (bool), ->section (stdClass from $this->sections).
 612       *      This does not contain page - get that from {@link get_question_page()} -
 613       *      or maxmark - get that from $this->quba.
 614       */
 615      protected $slots;
 616  
 617      /** @var array of quiz_sections rows, with a ->lastslot field added. */
 618      protected $sections;
 619  
 620      /** @var array page no => array of slot numbers on the page in order. */
 621      protected $pagelayout;
 622  
 623      /** @var array slot => displayed question number for this slot. (E.g. 1, 2, 3 or 'i'.) */
 624      protected $questionnumbers;
 625  
 626      /** @var array slot => page number for this slot. */
 627      protected $questionpages;
 628  
 629      /** @var mod_quiz_display_options cache for the appropriate review options. */
 630      protected $reviewoptions = null;
 631  
 632      // Constructor =============================================================
 633      /**
 634       * Constructor assuming we already have the necessary data loaded.
 635       *
 636       * @param object $attempt the row of the quiz_attempts table.
 637       * @param object $quiz the quiz object for this attempt and user.
 638       * @param object $cm the course_module object for this quiz.
 639       * @param object $course the row from the course table for the course we belong to.
 640       * @param bool $loadquestions (optional) if true, the default, load all the details
 641       *      of the state of each question. Else just set up the basic details of the attempt.
 642       */
 643      public function __construct($attempt, $quiz, $cm, $course, $loadquestions = true) {
 644          $this->attempt = $attempt;
 645          $this->quizobj = new quiz($quiz, $cm, $course);
 646  
 647          if ($loadquestions) {
 648              $this->load_questions();
 649          }
 650      }
 651  
 652      /**
 653       * Used by {create()} and {create_from_usage_id()}.
 654       *
 655       * @param array $conditions passed to $DB->get_record('quiz_attempts', $conditions).
 656       * @return quiz_attempt the desired instance of this class.
 657       */
 658      protected static function create_helper($conditions) {
 659          global $DB;
 660  
 661          $attempt = $DB->get_record('quiz_attempts', $conditions, '*', MUST_EXIST);
 662          $quiz = quiz_access_manager::load_quiz_and_settings($attempt->quiz);
 663          $course = $DB->get_record('course', array('id' => $quiz->course), '*', MUST_EXIST);
 664          $cm = get_coursemodule_from_instance('quiz', $quiz->id, $course->id, false, MUST_EXIST);
 665  
 666          // Update quiz with override information.
 667          $quiz = quiz_update_effective_access($quiz, $attempt->userid);
 668  
 669          return new quiz_attempt($attempt, $quiz, $cm, $course);
 670      }
 671  
 672      /**
 673       * Static function to create a new quiz_attempt object given an attemptid.
 674       *
 675       * @param int $attemptid the attempt id.
 676       * @return quiz_attempt the new quiz_attempt object
 677       */
 678      public static function create($attemptid) {
 679          return self::create_helper(array('id' => $attemptid));
 680      }
 681  
 682      /**
 683       * Static function to create a new quiz_attempt object given a usage id.
 684       *
 685       * @param int $usageid the attempt usage id.
 686       * @return quiz_attempt the new quiz_attempt object
 687       */
 688      public static function create_from_usage_id($usageid) {
 689          return self::create_helper(array('uniqueid' => $usageid));
 690      }
 691  
 692      /**
 693       * @param string $state one of the state constants like IN_PROGRESS.
 694       * @return string the human-readable state name.
 695       */
 696      public static function state_name($state) {
 697          return quiz_attempt_state_name($state);
 698      }
 699  
 700      /**
 701       * This method can be called later if the object was constructed with $loadqusetions = false.
 702       */
 703      public function load_questions() {
 704          global $DB;
 705  
 706          if (isset($this->quba)) {
 707              throw new coding_exception('This quiz attempt has already had the questions loaded.');
 708          }
 709  
 710          $this->quba = question_engine::load_questions_usage_by_activity($this->attempt->uniqueid);
 711          $this->slots = $DB->get_records('quiz_slots',
 712                  array('quizid' => $this->get_quizid()), 'slot',
 713                  'slot, id, requireprevious, questionid, includingsubcategories');
 714          $this->sections = array_values($DB->get_records('quiz_sections',
 715                  array('quizid' => $this->get_quizid()), 'firstslot'));
 716  
 717          $this->link_sections_and_slots();
 718          $this->determine_layout();
 719          $this->number_questions();
 720      }
 721  
 722      /**
 723       * Let each slot know which section it is part of.
 724       */
 725      protected function link_sections_and_slots() {
 726          foreach ($this->sections as $i => $section) {
 727              if (isset($this->sections[$i + 1])) {
 728                  $section->lastslot = $this->sections[$i + 1]->firstslot - 1;
 729              } else {
 730                  $section->lastslot = count($this->slots);
 731              }
 732              for ($slot = $section->firstslot; $slot <= $section->lastslot; $slot += 1) {
 733                  $this->slots[$slot]->section = $section;
 734              }
 735          }
 736      }
 737  
 738      /**
 739       * Parse attempt->layout to populate the other arrays the represent the layout.
 740       */
 741      protected function determine_layout() {
 742          $this->pagelayout = array();
 743  
 744          // Break up the layout string into pages.
 745          $pagelayouts = explode(',0', $this->attempt->layout);
 746  
 747          // Strip off any empty last page (normally there is one).
 748          if (end($pagelayouts) == '') {
 749              array_pop($pagelayouts);
 750          }
 751  
 752          // File the ids into the arrays.
 753          // Tracking which is the first slot in each section in this attempt is
 754          // trickier than you might guess, since the slots in this section
 755          // may be shuffled, so $section->firstslot (the lowest numbered slot in
 756          // the section) may not be the first one.
 757          $unseensections = $this->sections;
 758          $this->pagelayout = array();
 759          foreach ($pagelayouts as $page => $pagelayout) {
 760              $pagelayout = trim($pagelayout, ',');
 761              if ($pagelayout == '') {
 762                  continue;
 763              }
 764              $this->pagelayout[$page] = explode(',', $pagelayout);
 765              foreach ($this->pagelayout[$page] as $slot) {
 766                  $sectionkey = array_search($this->slots[$slot]->section, $unseensections);
 767                  if ($sectionkey !== false) {
 768                      $this->slots[$slot]->firstinsection = true;
 769                      unset($unseensections[$sectionkey]);
 770                  } else {
 771                      $this->slots[$slot]->firstinsection = false;
 772                  }
 773              }
 774          }
 775      }
 776  
 777      /**
 778       * Work out the number to display for each question/slot.
 779       */
 780      protected function number_questions() {
 781          $number = 1;
 782          foreach ($this->pagelayout as $page => $slots) {
 783              foreach ($slots as $slot) {
 784                  if ($length = $this->is_real_question($slot)) {
 785                      $this->questionnumbers[$slot] = $number;
 786                      $number += $length;
 787                  } else {
 788                      $this->questionnumbers[$slot] = get_string('infoshort', 'quiz');
 789                  }
 790                  $this->questionpages[$slot] = $page;
 791              }
 792          }
 793      }
 794  
 795      /**
 796       * If the given page number is out of range (before the first page, or after
 797       * the last page, chnage it to be within range).
 798       *
 799       * @param int $page the requested page number.
 800       * @return int a safe page number to use.
 801       */
 802      public function force_page_number_into_range($page) {
 803          return min(max($page, 0), count($this->pagelayout) - 1);
 804      }
 805  
 806      // Simple getters ==========================================================
 807      public function get_quiz() {
 808          return $this->quizobj->get_quiz();
 809      }
 810  
 811      public function get_quizobj() {
 812          return $this->quizobj;
 813      }
 814  
 815      /** @return int the course id. */
 816      public function get_courseid() {
 817          return $this->quizobj->get_courseid();
 818      }
 819  
 820      /**
 821       * Get the course settings object.
 822       *
 823       * @return stdClass the course settings object.
 824       */
 825      public function get_course() {
 826          return $this->quizobj->get_course();
 827      }
 828  
 829      /** @return int the quiz id. */
 830      public function get_quizid() {
 831          return $this->quizobj->get_quizid();
 832      }
 833  
 834      /** @return string the name of this quiz. */
 835      public function get_quiz_name() {
 836          return $this->quizobj->get_quiz_name();
 837      }
 838  
 839      /** @return int the quiz navigation method. */
 840      public function get_navigation_method() {
 841          return $this->quizobj->get_navigation_method();
 842      }
 843  
 844      /** @return object the course_module object. */
 845      public function get_cm() {
 846          return $this->quizobj->get_cm();
 847      }
 848  
 849      /**
 850       * Get the course-module id.
 851       *
 852       * @return int the course_module id.
 853       */
 854      public function get_cmid() {
 855          return $this->quizobj->get_cmid();
 856      }
 857  
 858      /**
 859       * @return bool whether the current user is someone who previews the quiz,
 860       * rather than attempting it.
 861       */
 862      public function is_preview_user() {
 863          return $this->quizobj->is_preview_user();
 864      }
 865  
 866      /** @return int the number of attempts allowed at this quiz (0 = infinite). */
 867      public function get_num_attempts_allowed() {
 868          return $this->quizobj->get_num_attempts_allowed();
 869      }
 870  
 871      /** @return int number fo pages in this quiz. */
 872      public function get_num_pages() {
 873          return count($this->pagelayout);
 874      }
 875  
 876      /**
 877       * @param int $timenow the current time as a unix timestamp.
 878       * @return quiz_access_manager and instance of the quiz_access_manager class
 879       *      for this quiz at this time.
 880       */
 881      public function get_access_manager($timenow) {
 882          return $this->quizobj->get_access_manager($timenow);
 883      }
 884  
 885      /** @return int the attempt id. */
 886      public function get_attemptid() {
 887          return $this->attempt->id;
 888      }
 889  
 890      /** @return int the attempt unique id. */
 891      public function get_uniqueid() {
 892          return $this->attempt->uniqueid;
 893      }
 894  
 895      /** @return object the row from the quiz_attempts table. */
 896      public function get_attempt() {
 897          return $this->attempt;
 898      }
 899  
 900      /** @return int the number of this attemp (is it this user's first, second, ... attempt). */
 901      public function get_attempt_number() {
 902          return $this->attempt->attempt;
 903      }
 904  
 905      /** @return string one of the quiz_attempt::IN_PROGRESS, FINISHED, OVERDUE or ABANDONED constants. */
 906      public function get_state() {
 907          return $this->attempt->state;
 908      }
 909  
 910      /** @return int the id of the user this attempt belongs to. */
 911      public function get_userid() {
 912          return $this->attempt->userid;
 913      }
 914  
 915      /** @return int the current page of the attempt. */
 916      public function get_currentpage() {
 917          return $this->attempt->currentpage;
 918      }
 919  
 920      public function get_sum_marks() {
 921          return $this->attempt->sumgrades;
 922      }
 923  
 924      /**
 925       * @return bool whether this attempt has been finished (true) or is still
 926       *     in progress (false). Be warned that this is not just state == self::FINISHED,
 927       *     it also includes self::ABANDONED.
 928       */
 929      public function is_finished() {
 930          return $this->attempt->state == self::FINISHED || $this->attempt->state == self::ABANDONED;
 931      }
 932  
 933      /** @return bool whether this attempt is a preview attempt. */
 934      public function is_preview() {
 935          return $this->attempt->preview;
 936      }
 937  
 938      /**
 939       * Is this someone dealing with their own attempt or preview?
 940       *
 941       * @return bool true => own attempt/preview. false => reviewing someone else's.
 942       */
 943      public function is_own_attempt() {
 944          global $USER;
 945          return $this->attempt->userid == $USER->id;
 946      }
 947  
 948      /**
 949       * @return bool whether this attempt is a preview belonging to the current user.
 950       */
 951      public function is_own_preview() {
 952          return $this->is_own_attempt() &&
 953                  $this->is_preview_user() && $this->attempt->preview;
 954      }
 955  
 956      /**
 957       * Is the current user allowed to review this attempt. This applies when
 958       * {@link is_own_attempt()} returns false.
 959       *
 960       * @return bool whether the review should be allowed.
 961       */
 962      public function is_review_allowed() {
 963          if (!$this->has_capability('mod/quiz:viewreports')) {
 964              return false;
 965          }
 966  
 967          $cm = $this->get_cm();
 968          if ($this->has_capability('moodle/site:accessallgroups') ||
 969                  groups_get_activity_groupmode($cm) != SEPARATEGROUPS) {
 970              return true;
 971          }
 972  
 973          // Check the users have at least one group in common.
 974          $teachersgroups = groups_get_activity_allowed_groups($cm);
 975          $studentsgroups = groups_get_all_groups(
 976                  $cm->course, $this->attempt->userid, $cm->groupingid);
 977          return $teachersgroups && $studentsgroups &&
 978                  array_intersect(array_keys($teachersgroups), array_keys($studentsgroups));
 979      }
 980  
 981      /**
 982       * Has the student, in this attempt, engaged with the quiz in a non-trivial way?
 983       *
 984       * That is, is there any question worth a non-zero number of marks, where
 985       * the student has made some response that we have saved?
 986       *
 987       * @return bool true if we have saved a response for at least one graded question.
 988       */
 989      public function has_response_to_at_least_one_graded_question() {
 990          foreach ($this->quba->get_attempt_iterator() as $qa) {
 991              if ($qa->get_max_mark() == 0) {
 992                  continue;
 993              }
 994              if ($qa->get_num_steps() > 1) {
 995                  return true;
 996              }
 997          }
 998          return false;
 999      }
1000  
1001      /**
1002       * Get extra summary information about this attempt.
1003       *
1004       * Some behaviours may be able to provide interesting summary information
1005       * about the attempt as a whole, and this method provides access to that data.
1006       * To see how this works, try setting a quiz to one of the CBM behaviours,
1007       * and then look at the extra information displayed at the top of the quiz
1008       * review page once you have sumitted an attempt.
1009       *
1010       * In the return value, the array keys are identifiers of the form
1011       * qbehaviour_behaviourname_meaningfullkey. For qbehaviour_deferredcbm_highsummary.
1012       * The values are arrays with two items, title and content. Each of these
1013       * will be either a string, or a renderable.
1014       *
1015       * @param question_display_options $options the display options for this quiz attempt at this time.
1016       * @return array as described above.
1017       */
1018      public function get_additional_summary_data(question_display_options $options) {
1019          return $this->quba->get_summary_information($options);
1020      }
1021  
1022      /**
1023       * Get the overall feedback corresponding to a particular mark.
1024       *
1025       * @param number $grade a particular grade.
1026       * @return string the feedback.
1027       */
1028      public function get_overall_feedback($grade) {
1029          return quiz_feedback_for_grade($grade, $this->get_quiz(),
1030                  $this->quizobj->get_context());
1031      }
1032  
1033      /**
1034       * Wrapper round the has_capability funciton that automatically passes in the quiz context.
1035       *
1036       * @param string $capability the name of the capability to check. For example mod/forum:view.
1037       * @param int|null $userid A user id. By default (null) checks the permissions of the current user.
1038       * @param bool $doanything If false, ignore effect of admin role assignment.
1039       * @return boolean true if the user has this capability. Otherwise false.
1040       */
1041      public function has_capability($capability, $userid = null, $doanything = true) {
1042          return $this->quizobj->has_capability($capability, $userid, $doanything);
1043      }
1044  
1045      /**
1046       * Wrapper round the require_capability function that automatically passes in the quiz context.
1047       *
1048       * @param string $capability the name of the capability to check. For example mod/forum:view.
1049       * @param int|null $userid A user id. By default (null) checks the permissions of the current user.
1050       * @param bool $doanything If false, ignore effect of admin role assignment.
1051       */
1052      public function require_capability($capability, $userid = null, $doanything = true) {
1053          $this->quizobj->require_capability($capability, $userid, $doanything);
1054      }
1055  
1056      /**
1057       * Check the appropriate capability to see whether this user may review their own attempt.
1058       * If not, prints an error.
1059       */
1060      public function check_review_capability() {
1061          if ($this->get_attempt_state() == mod_quiz_display_options::IMMEDIATELY_AFTER) {
1062              $capability = 'mod/quiz:attempt';
1063          } else {
1064              $capability = 'mod/quiz:reviewmyattempts';
1065          }
1066  
1067          // These next tests are in a slighly funny order. The point is that the
1068          // common and most performance-critical case is students attempting a quiz
1069          // so we want to check that permisison first.
1070  
1071          if ($this->has_capability($capability)) {
1072              // User has the permission that lets you do the quiz as a student. Fine.
1073              return;
1074          }
1075  
1076          if ($this->has_capability('mod/quiz:viewreports') ||
1077                  $this->has_capability('mod/quiz:preview')) {
1078              // User has the permission that lets teachers review. Fine.
1079              return;
1080          }
1081  
1082          // They should not be here. Trigger the standard no-permission error
1083          // but using the name of the student capability.
1084          // We know this will fail. We just want the stadard exception thown.
1085          $this->require_capability($capability);
1086      }
1087  
1088      /**
1089       * Checks whether a user may navigate to a particular slot.
1090       *
1091       * @param int $slot the target slot (currently does not affect the answer).
1092       * @return bool true if the navigation should be allowed.
1093       */
1094      public function can_navigate_to($slot) {
1095          if ($this->attempt->state == self::OVERDUE) {
1096              // When the attempt is overdue, students can only see the
1097              // attempt summary page and cannot navigate anywhere else.
1098              return false;
1099          }
1100  
1101          switch ($this->get_navigation_method()) {
1102              case QUIZ_NAVMETHOD_FREE:
1103                  return true;
1104                  break;
1105              case QUIZ_NAVMETHOD_SEQ:
1106                  return false;
1107                  break;
1108          }
1109          return true;
1110      }
1111  
1112      /**
1113       * @return int one of the mod_quiz_display_options::DURING,
1114       *      IMMEDIATELY_AFTER, LATER_WHILE_OPEN or AFTER_CLOSE constants.
1115       */
1116      public function get_attempt_state() {
1117          return quiz_attempt_state($this->get_quiz(), $this->attempt);
1118      }
1119  
1120      /**
1121       * Wrapper that the correct mod_quiz_display_options for this quiz at the
1122       * moment.
1123       *
1124       * @param bool $reviewing true for options when reviewing, false for when attempting.
1125       * @return question_display_options the render options for this user on this attempt.
1126       */
1127      public function get_display_options($reviewing) {
1128          if ($reviewing) {
1129              if (is_null($this->reviewoptions)) {
1130                  $this->reviewoptions = quiz_get_review_options($this->get_quiz(),
1131                          $this->attempt, $this->quizobj->get_context());
1132                  if ($this->is_own_preview()) {
1133                      // It should  always be possible for a teacher to review their
1134                      // own preview irrespective of the review options settings.
1135                      $this->reviewoptions->attempt = true;
1136                  }
1137              }
1138              return $this->reviewoptions;
1139  
1140          } else {
1141              $options = mod_quiz_display_options::make_from_quiz($this->get_quiz(),
1142                      mod_quiz_display_options::DURING);
1143              $options->flags = quiz_get_flag_option($this->attempt, $this->quizobj->get_context());
1144              return $options;
1145          }
1146      }
1147  
1148      /**
1149       * Wrapper that the correct mod_quiz_display_options for this quiz at the
1150       * moment.
1151       *
1152       * @param bool $reviewing true for review page, else attempt page.
1153       * @param int $slot which question is being displayed.
1154       * @param moodle_url $thispageurl to return to after the editing form is
1155       *      submitted or cancelled. If null, no edit link will be generated.
1156       *
1157       * @return question_display_options the render options for this user on this
1158       *      attempt, with extra info to generate an edit link, if applicable.
1159       */
1160      public function get_display_options_with_edit_link($reviewing, $slot, $thispageurl) {
1161          $options = clone($this->get_display_options($reviewing));
1162  
1163          if (!$thispageurl) {
1164              return $options;
1165          }
1166  
1167          if (!($reviewing || $this->is_preview())) {
1168              return $options;
1169          }
1170  
1171          $question = $this->quba->get_question($slot, false);
1172          if (!question_has_capability_on($question, 'edit', $question->category)) {
1173              return $options;
1174          }
1175  
1176          $options->editquestionparams['cmid'] = $this->get_cmid();
1177          $options->editquestionparams['returnurl'] = $thispageurl;
1178  
1179          return $options;
1180      }
1181  
1182      /**
1183       * @param int $page page number
1184       * @return bool true if this is the last page of the quiz.
1185       */
1186      public function is_last_page($page) {
1187          return $page == count($this->pagelayout) - 1;
1188      }
1189  
1190      /**
1191       * Return the list of slot numbers for either a given page of the quiz, or for the
1192       * whole quiz.
1193       *
1194       * @param mixed $page string 'all' or integer page number.
1195       * @return array the requested list of slot numbers.
1196       */
1197      public function get_slots($page = 'all') {
1198          if ($page === 'all') {
1199              $numbers = array();
1200              foreach ($this->pagelayout as $numbersonpage) {
1201                  $numbers = array_merge($numbers, $numbersonpage);
1202              }
1203              return $numbers;
1204          } else {
1205              return $this->pagelayout[$page];
1206          }
1207      }
1208  
1209      /**
1210       * Return the list of slot numbers for either a given page of the quiz, or for the
1211       * whole quiz.
1212       *
1213       * @param mixed $page string 'all' or integer page number.
1214       * @return array the requested list of slot numbers.
1215       */
1216      public function get_active_slots($page = 'all') {
1217          $activeslots = array();
1218          foreach ($this->get_slots($page) as $slot) {
1219              if (!$this->is_blocked_by_previous_question($slot)) {
1220                  $activeslots[] = $slot;
1221              }
1222          }
1223          return $activeslots;
1224      }
1225  
1226      /**
1227       * Helper method for unit tests. Get the underlying question usage object.
1228       *
1229       * @return question_usage_by_activity the usage.
1230       */
1231      public function get_question_usage() {
1232          if (!(PHPUNIT_TEST || defined('BEHAT_TEST'))) {
1233              throw new coding_exception('get_question_usage is only for use in unit tests. ' .
1234                      'For other operations, use the quiz_attempt api, or extend it properly.');
1235          }
1236          return $this->quba;
1237      }
1238  
1239      /**
1240       * Get the question_attempt object for a particular question in this attempt.
1241       *
1242       * @param int $slot the number used to identify this question within this attempt.
1243       * @return question_attempt the requested question_attempt.
1244       */
1245      public function get_question_attempt($slot) {
1246          return $this->quba->get_question_attempt($slot);
1247      }
1248  
1249      /**
1250       * Get all the question_attempt objects that have ever appeared in a given slot.
1251       *
1252       * This relates to the 'Try another question like this one' feature.
1253       *
1254       * @param int $slot the number used to identify this question within this attempt.
1255       * @return question_attempt[] the attempts.
1256       */
1257      public function all_question_attempts_originally_in_slot($slot) {
1258          $qas = array();
1259          foreach ($this->quba->get_attempt_iterator() as $qa) {
1260              if ($qa->get_metadata('originalslot') == $slot) {
1261                  $qas[] = $qa;
1262              }
1263          }
1264          $qas[] = $this->quba->get_question_attempt($slot);
1265          return $qas;
1266      }
1267  
1268      /**
1269       * Is a particular question in this attempt a real question, or something like a description.
1270       *
1271       * @param int $slot the number used to identify this question within this attempt.
1272       * @return int whether that question is a real question. Actually returns the
1273       *     question length, which could theoretically be greater than one.
1274       */
1275      public function is_real_question($slot) {
1276          return $this->quba->get_question($slot, false)->length;
1277      }
1278  
1279      /**
1280       * Is a particular question in this attempt a real question, or something like a description.
1281       *
1282       * @param int $slot the number used to identify this question within this attempt.
1283       * @return bool whether that question is a real question.
1284       */
1285      public function is_question_flagged($slot) {
1286          return $this->quba->get_question_attempt($slot)->is_flagged();
1287      }
1288  
1289      /**
1290       * Checks whether the question in this slot requires the previous
1291       * question to have been completed.
1292       *
1293       * @param int $slot the number used to identify this question within this attempt.
1294       * @return bool whether the previous question must have been completed before
1295       *      this one can be seen.
1296       */
1297      public function is_blocked_by_previous_question($slot) {
1298          return $slot > 1 && isset($this->slots[$slot]) && $this->slots[$slot]->requireprevious &&
1299                  !$this->slots[$slot]->section->shufflequestions &&
1300                  !$this->slots[$slot - 1]->section->shufflequestions &&
1301                  $this->get_navigation_method() != QUIZ_NAVMETHOD_SEQ &&
1302                  !$this->get_question_state($slot - 1)->is_finished() &&
1303                  $this->quba->can_question_finish_during_attempt($slot - 1);
1304      }
1305  
1306      /**
1307       * Is it possible for this question to be re-started within this attempt?
1308       *
1309       * @param int $slot the number used to identify this question within this attempt.
1310       * @return bool whether the student should be given the option to restart this question now.
1311       */
1312      public function can_question_be_redone_now($slot) {
1313          return $this->get_quiz()->canredoquestions && !$this->is_finished() &&
1314                  $this->get_question_state($slot)->is_finished();
1315      }
1316  
1317      /**
1318       * Given a slot in this attempt, which may or not be a redone question, return the original slot.
1319       *
1320       * @param int $slot identifies a particular question in this attempt.
1321       * @return int the slot where this question was originally.
1322       */
1323      public function get_original_slot($slot) {
1324          $originalslot = $this->quba->get_question_attempt_metadata($slot, 'originalslot');
1325          if ($originalslot) {
1326              return $originalslot;
1327          } else {
1328              return $slot;
1329          }
1330      }
1331  
1332      /**
1333       * Get the displayed question number for a slot.
1334       *
1335       * @param int $slot the number used to identify this question within this attempt.
1336       * @return string the displayed question number for the question in this slot.
1337       *      For example '1', '2', '3' or 'i'.
1338       */
1339      public function get_question_number($slot) {
1340          return $this->questionnumbers[$slot];
1341      }
1342  
1343      /**
1344       * If the section heading, if any, that should come just before this slot.
1345       *
1346       * @param int $slot identifies a particular question in this attempt.
1347       * @return string the required heading, or null if there is not one here.
1348       */
1349      public function get_heading_before_slot($slot) {
1350          if ($this->slots[$slot]->firstinsection) {
1351              return $this->slots[$slot]->section->heading;
1352          } else {
1353              return null;
1354          }
1355      }
1356  
1357      /**
1358       * Return the page of the quiz where this question appears.
1359       *
1360       * @param int $slot the number used to identify this question within this attempt.
1361       * @return int the page of the quiz this question appears on.
1362       */
1363      public function get_question_page($slot) {
1364          return $this->questionpages[$slot];
1365      }
1366  
1367      /**
1368       * Return the grade obtained on a particular question, if the user is permitted
1369       * to see it. You must previously have called load_question_states to load the
1370       * state data about this question.
1371       *
1372       * @param int $slot the number used to identify this question within this attempt.
1373       * @return string the formatted grade, to the number of decimal places specified
1374       *      by the quiz.
1375       */
1376      public function get_question_name($slot) {
1377          return $this->quba->get_question($slot, false)->name;
1378      }
1379  
1380      /**
1381       * Return the {@link question_state} that this question is in.
1382       *
1383       * @param int $slot the number used to identify this question within this attempt.
1384       * @return question_state the state this question is in.
1385       */
1386      public function get_question_state($slot) {
1387          return $this->quba->get_question_state($slot);
1388      }
1389  
1390      /**
1391       * Return the grade obtained on a particular question, if the user is permitted
1392       * to see it. You must previously have called load_question_states to load the
1393       * state data about this question.
1394       *
1395       * @param int $slot the number used to identify this question within this attempt.
1396       * @param bool $showcorrectness Whether right/partial/wrong states should
1397       *      be distinguished.
1398       * @return string the formatted grade, to the number of decimal places specified
1399       *      by the quiz.
1400       */
1401      public function get_question_status($slot, $showcorrectness) {
1402          return $this->quba->get_question_state_string($slot, $showcorrectness);
1403      }
1404  
1405      /**
1406       * Return the grade obtained on a particular question, if the user is permitted
1407       * to see it. You must previously have called load_question_states to load the
1408       * state data about this question.
1409       *
1410       * @param int $slot the number used to identify this question within this attempt.
1411       * @param bool $showcorrectness Whether right/partial/wrong states should
1412       *      be distinguished.
1413       * @return string class name for this state.
1414       */
1415      public function get_question_state_class($slot, $showcorrectness) {
1416          return $this->quba->get_question_state_class($slot, $showcorrectness);
1417      }
1418  
1419      /**
1420       * Return the grade obtained on a particular question.
1421       *
1422       * You must previously have called load_question_states to load the state
1423       * data about this question.
1424       *
1425       * @param int $slot the number used to identify this question within this attempt.
1426       * @return string the formatted grade, to the number of decimal places specified by the quiz.
1427       */
1428      public function get_question_mark($slot) {
1429          return quiz_format_question_grade($this->get_quiz(), $this->quba->get_question_mark($slot));
1430      }
1431  
1432      /**
1433       * Get the time of the most recent action performed on a question.
1434       *
1435       * @param int $slot the number used to identify this question within this usage.
1436       * @return int timestamp.
1437       */
1438      public function get_question_action_time($slot) {
1439          return $this->quba->get_question_action_time($slot);
1440      }
1441  
1442      /**
1443       * Return the question type name for a given slot within the current attempt.
1444       *
1445       * @param int $slot the number used to identify this question within this attempt.
1446       * @return string the question type name.
1447       * @since  Moodle 3.1
1448       */
1449      public function get_question_type_name($slot) {
1450          return $this->quba->get_question($slot, false)->get_type_name();
1451      }
1452  
1453      /**
1454       * Get the time remaining for an in-progress attempt, if the time is short
1455       * enough that it would be worth showing a timer.
1456       *
1457       * @param int $timenow the time to consider as 'now'.
1458       * @return int|false the number of seconds remaining for this attempt.
1459       *      False if there is no limit.
1460       */
1461      public function get_time_left_display($timenow) {
1462          if ($this->attempt->state != self::IN_PROGRESS) {
1463              return false;
1464          }
1465          return $this->get_access_manager($timenow)->get_time_left_display($this->attempt, $timenow);
1466      }
1467  
1468  
1469      /**
1470       * @return int the time when this attempt was submitted. 0 if it has not been
1471       * submitted yet.
1472       */
1473      public function get_submitted_date() {
1474          return $this->attempt->timefinish;
1475      }
1476  
1477      /**
1478       * If the attempt is in an applicable state, work out the time by which the
1479       * student should next do something.
1480       *
1481       * @return int timestamp by which the student needs to do something.
1482       */
1483      public function get_due_date() {
1484          $deadlines = array();
1485          if ($this->quizobj->get_quiz()->timelimit) {
1486              $deadlines[] = $this->attempt->timestart + $this->quizobj->get_quiz()->timelimit;
1487          }
1488          if ($this->quizobj->get_quiz()->timeclose) {
1489              $deadlines[] = $this->quizobj->get_quiz()->timeclose;
1490          }
1491          if ($deadlines) {
1492              $duedate = min($deadlines);
1493          } else {
1494              return false;
1495          }
1496  
1497          switch ($this->attempt->state) {
1498              case self::IN_PROGRESS:
1499                  return $duedate;
1500  
1501              case self::OVERDUE:
1502                  return $duedate + $this->quizobj->get_quiz()->graceperiod;
1503  
1504              default:
1505                  throw new coding_exception('Unexpected state: ' . $this->attempt->state);
1506          }
1507      }
1508  
1509      // URLs related to this attempt ============================================
1510      /**
1511       * @return string quiz view url.
1512       */
1513      public function view_url() {
1514          return $this->quizobj->view_url();
1515      }
1516  
1517      /**
1518       * Get the URL to start or continue an attempt.
1519       *
1520       * @param int|null $slot which question in the attempt to go to after starting (optional).
1521       * @param int $page which page in the attempt to go to after starting.
1522       * @return string the URL of this quiz's edit page. Needs to be POSTed to with a cmid parameter.
1523       */
1524      public function start_attempt_url($slot = null, $page = -1) {
1525          if ($page == -1 && !is_null($slot)) {
1526              $page = $this->get_question_page($slot);
1527          } else {
1528              $page = 0;
1529          }
1530          return $this->quizobj->start_attempt_url($page);
1531      }
1532  
1533      /**
1534       * Generates the title of the attempt page.
1535       *
1536       * @param int $page the page number (starting with 0) in the attempt.
1537       * @return string attempt page title.
1538       */
1539      public function attempt_page_title(int $page) : string {
1540          if ($this->get_num_pages() > 1) {
1541              $a = new stdClass();
1542              $a->name = $this->get_quiz_name();
1543              $a->currentpage = $page + 1;
1544              $a->totalpages = $this->get_num_pages();
1545              $title = get_string('attempttitlepaged', 'quiz', $a);
1546          } else {
1547              $title = get_string('attempttitle', 'quiz', $this->get_quiz_name());
1548          }
1549  
1550          return $title;
1551      }
1552  
1553      /**
1554       * @param int|null $slot if specified, the slot number of a specific question to link to.
1555       * @param int $page if specified, a particular page to link to. If not given deduced
1556       *      from $slot, or goes to the first page.
1557       * @param int $thispage if not -1, the current page. Will cause links to other things on
1558       * this page to be output as only a fragment.
1559       * @return string the URL to continue this attempt.
1560       */
1561      public function attempt_url($slot = null, $page = -1, $thispage = -1) {
1562          return $this->page_and_question_url('attempt', $slot, $page, false, $thispage);
1563      }
1564  
1565      /**
1566       * Generates the title of the summary page.
1567       *
1568       * @return string summary page title.
1569       */
1570      public function summary_page_title() : string {
1571          return get_string('attemptsummarytitle', 'quiz', $this->get_quiz_name());
1572      }
1573  
1574      /**
1575       * @return moodle_url the URL of this quiz's summary page.
1576       */
1577      public function summary_url() {
1578          return new moodle_url('/mod/quiz/summary.php', array('attempt' => $this->attempt->id, 'cmid' => $this->get_cmid()));
1579      }
1580  
1581      /**
1582       * @return moodle_url the URL of this quiz's summary page.
1583       */
1584      public function processattempt_url() {
1585          return new moodle_url('/mod/quiz/processattempt.php');
1586      }
1587  
1588      /**
1589       * Generates the title of the review page.
1590       *
1591       * @param int $page the page number (starting with 0) in the attempt.
1592       * @param bool $showall whether the review page contains the entire attempt on one page.
1593       * @return string title of the review page.
1594       */
1595      public function review_page_title(int $page, bool $showall = false) : string {
1596          if (!$showall && $this->get_num_pages() > 1) {
1597              $a = new stdClass();
1598              $a->name = $this->get_quiz_name();
1599              $a->currentpage = $page + 1;
1600              $a->totalpages = $this->get_num_pages();
1601              $title = get_string('attemptreviewtitlepaged', 'quiz', $a);
1602          } else {
1603              $title = get_string('attemptreviewtitle', 'quiz', $this->get_quiz_name());
1604          }
1605  
1606          return $title;
1607      }
1608  
1609      /**
1610       * @param int|null $slot indicates which question to link to.
1611       * @param int $page if specified, the URL of this particular page of the attempt, otherwise
1612       *      the URL will go to the first page.  If -1, deduce $page from $slot.
1613       * @param bool|null $showall if true, the URL will be to review the entire attempt on one page,
1614       *      and $page will be ignored. If null, a sensible default will be chosen.
1615       * @param int $thispage if not -1, the current page. Will cause links to other things on
1616       *      this page to be output as only a fragment.
1617       * @return string the URL to review this attempt.
1618       */
1619      public function review_url($slot = null, $page = -1, $showall = null, $thispage = -1) {
1620          return $this->page_and_question_url('review', $slot, $page, $showall, $thispage);
1621      }
1622  
1623      /**
1624       * By default, should this script show all questions on one page for this attempt?
1625       *
1626       * @param string $script the script name, e.g. 'attempt', 'summary', 'review'.
1627       * @return bool whether show all on one page should be on by default.
1628       */
1629      public function get_default_show_all($script) {
1630          return $script == 'review' && count($this->questionpages) < self::MAX_SLOTS_FOR_DEFAULT_REVIEW_SHOW_ALL;
1631      }
1632  
1633      // Bits of content =========================================================
1634  
1635      /**
1636       * If $reviewoptions->attempt is false, meaning that students can't review this
1637       * attempt at the moment, return an appropriate string explaining why.
1638       *
1639       * @param bool $short if true, return a shorter string.
1640       * @return string an appropriate message.
1641       */
1642      public function cannot_review_message($short = false) {
1643          return $this->quizobj->cannot_review_message(
1644                  $this->get_attempt_state(), $short);
1645      }
1646  
1647      /**
1648       * Initialise the JS etc. required all the questions on a page.
1649       *
1650       * @param int|string $page a page number, or 'all'.
1651       * @param bool $showall if true forces page number to all.
1652       * @return string HTML to output - mostly obsolete, will probably be an empty string.
1653       */
1654      public function get_html_head_contributions($page = 'all', $showall = false) {
1655          if ($showall) {
1656              $page = 'all';
1657          }
1658          $result = '';
1659          foreach ($this->get_slots($page) as $slot) {
1660              $result .= $this->quba->render_question_head_html($slot);
1661          }
1662          $result .= question_engine::initialise_js();
1663          return $result;
1664      }
1665  
1666      /**
1667       * Initialise the JS etc. required by one question.
1668       *
1669       * @param int $slot the question slot number.
1670       * @return string HTML to output - but this is mostly obsolete. Will probably be an empty string.
1671       */
1672      public function get_question_html_head_contributions($slot) {
1673          return $this->quba->render_question_head_html($slot) .
1674                  question_engine::initialise_js();
1675      }
1676  
1677      /**
1678       * Print the HTML for the start new preview button, if the current user
1679       * is allowed to see one.
1680       *
1681       * @return string HTML for the button.
1682       */
1683      public function restart_preview_button() {
1684          global $OUTPUT;
1685          if ($this->is_preview() && $this->is_preview_user()) {
1686              return $OUTPUT->single_button(new moodle_url(
1687                      $this->start_attempt_url(), array('forcenew' => true)),
1688                      get_string('startnewpreview', 'quiz'));
1689          } else {
1690              return '';
1691          }
1692      }
1693  
1694      /**
1695       * Generate the HTML that displayes the question in its current state, with
1696       * the appropriate display options.
1697       *
1698       * @param int $slot identifies the question in the attempt.
1699       * @param bool $reviewing is the being printed on an attempt or a review page.
1700       * @param mod_quiz_renderer $renderer the quiz renderer.
1701       * @param moodle_url $thispageurl the URL of the page this question is being printed on.
1702       * @return string HTML for the question in its current state.
1703       */
1704      public function render_question($slot, $reviewing, mod_quiz_renderer $renderer, $thispageurl = null) {
1705          if ($this->is_blocked_by_previous_question($slot)) {
1706              $placeholderqa = $this->make_blocked_question_placeholder($slot);
1707  
1708              $displayoptions = $this->get_display_options($reviewing);
1709              $displayoptions->manualcomment = question_display_options::HIDDEN;
1710              $displayoptions->history = question_display_options::HIDDEN;
1711              $displayoptions->readonly = true;
1712  
1713              return html_writer::div($placeholderqa->render($displayoptions,
1714                      $this->get_question_number($this->get_original_slot($slot))),
1715                      'mod_quiz-blocked_question_warning');
1716          }
1717  
1718          return $this->render_question_helper($slot, $reviewing, $thispageurl, $renderer, null);
1719      }
1720  
1721      /**
1722       * Helper used by {@link render_question()} and {@link render_question_at_step()}.
1723       *
1724       * @param int $slot identifies the question in the attempt.
1725       * @param bool $reviewing is the being printed on an attempt or a review page.
1726       * @param moodle_url $thispageurl the URL of the page this question is being printed on.
1727       * @param mod_quiz_renderer $renderer the quiz renderer.
1728       * @param int|null $seq the seq number of the past state to display.
1729       * @return string HTML fragment.
1730       */
1731      protected function render_question_helper($slot, $reviewing, $thispageurl,
1732              mod_quiz_renderer $renderer, $seq) {
1733          $originalslot = $this->get_original_slot($slot);
1734          $number = $this->get_question_number($originalslot);
1735          $displayoptions = $this->get_display_options_with_edit_link($reviewing, $slot, $thispageurl);
1736  
1737          if ($slot != $originalslot) {
1738              $originalmaxmark = $this->get_question_attempt($slot)->get_max_mark();
1739              $this->get_question_attempt($slot)->set_max_mark($this->get_question_attempt($originalslot)->get_max_mark());
1740          }
1741  
1742          if ($this->can_question_be_redone_now($slot)) {
1743              $displayoptions->extrainfocontent = $renderer->redo_question_button(
1744                      $slot, $displayoptions->readonly);
1745          }
1746  
1747          if ($displayoptions->history && $displayoptions->questionreviewlink) {
1748              $links = $this->links_to_other_redos($slot, $displayoptions->questionreviewlink);
1749              if ($links) {
1750                  $displayoptions->extrahistorycontent = html_writer::tag('p',
1751                          get_string('redoesofthisquestion', 'quiz', $renderer->render($links)));
1752              }
1753          }
1754  
1755          if ($seq === null) {
1756              $output = $this->quba->render_question($slot, $displayoptions, $number);
1757          } else {
1758              $output = $this->quba->render_question_at_step($slot, $seq, $displayoptions, $number);
1759          }
1760  
1761          if ($slot != $originalslot) {
1762              $this->get_question_attempt($slot)->set_max_mark($originalmaxmark);
1763          }
1764  
1765          return $output;
1766      }
1767  
1768      /**
1769       * Create a fake question to be displayed in place of a question that is blocked
1770       * until the previous question has been answered.
1771       *
1772       * @param int $slot int slot number of the question to replace.
1773       * @return question_attempt the placeholder question attempt.
1774       */
1775      protected function make_blocked_question_placeholder($slot) {
1776          $replacedquestion = $this->get_question_attempt($slot)->get_question(false);
1777  
1778          question_bank::load_question_definition_classes('description');
1779          $question = new qtype_description_question();
1780          $question->id = $replacedquestion->id;
1781          $question->category = null;
1782          $question->parent = 0;
1783          $question->qtype = question_bank::get_qtype('description');
1784          $question->name = '';
1785          $question->questiontext = get_string('questiondependsonprevious', 'quiz');
1786          $question->questiontextformat = FORMAT_HTML;
1787          $question->generalfeedback = '';
1788          $question->defaultmark = $this->quba->get_question_max_mark($slot);
1789          $question->length = $replacedquestion->length;
1790          $question->penalty = 0;
1791          $question->stamp = '';
1792          $question->version = 0;
1793          $question->hidden = 0;
1794          $question->timecreated = null;
1795          $question->timemodified = null;
1796          $question->createdby = null;
1797          $question->modifiedby = null;
1798  
1799          $placeholderqa = new question_attempt($question, $this->quba->get_id(),
1800                  null, $this->quba->get_question_max_mark($slot));
1801          $placeholderqa->set_slot($slot);
1802          $placeholderqa->start($this->get_quiz()->preferredbehaviour, 1);
1803          $placeholderqa->set_flagged($this->is_question_flagged($slot));
1804          return $placeholderqa;
1805      }
1806  
1807      /**
1808       * Like {@link render_question()} but displays the question at the past step
1809       * indicated by $seq, rather than showing the latest step.
1810       *
1811       * @param int $slot the slot number of a question in this quiz attempt.
1812       * @param int $seq the seq number of the past state to display.
1813       * @param bool $reviewing is the being printed on an attempt or a review page.
1814       * @param mod_quiz_renderer $renderer the quiz renderer.
1815       * @param moodle_url $thispageurl the URL of the page this question is being printed on.
1816       * @return string HTML for the question in its current state.
1817       */
1818      public function render_question_at_step($slot, $seq, $reviewing,
1819              mod_quiz_renderer $renderer, $thispageurl = null) {
1820          return $this->render_question_helper($slot, $reviewing, $thispageurl, $renderer, $seq);
1821      }
1822  
1823      /**
1824       * Wrapper round print_question from lib/questionlib.php.
1825       *
1826       * @param int $slot the id of a question in this quiz attempt.
1827       * @return string HTML of the question.
1828       */
1829      public function render_question_for_commenting($slot) {
1830          $options = $this->get_display_options(true);
1831          $options->hide_all_feedback();
1832          $options->manualcomment = question_display_options::EDITABLE;
1833          return $this->quba->render_question($slot, $options,
1834                  $this->get_question_number($slot));
1835      }
1836  
1837      /**
1838       * Check wheter access should be allowed to a particular file.
1839       *
1840       * @param int $slot the slot of a question in this quiz attempt.
1841       * @param bool $reviewing is the being printed on an attempt or a review page.
1842       * @param int $contextid the file context id from the request.
1843       * @param string $component the file component from the request.
1844       * @param string $filearea the file area from the request.
1845       * @param array $args extra part components from the request.
1846       * @param bool $forcedownload whether to force download.
1847       * @return string HTML for the question in its current state.
1848       */
1849      public function check_file_access($slot, $reviewing, $contextid, $component,
1850              $filearea, $args, $forcedownload) {
1851          $options = $this->get_display_options($reviewing);
1852  
1853          // Check permissions - warning there is similar code in review.php and
1854          // reviewquestion.php. If you change on, change them all.
1855          if ($reviewing && $this->is_own_attempt() && !$options->attempt) {
1856              return false;
1857          }
1858  
1859          if ($reviewing && !$this->is_own_attempt() && !$this->is_review_allowed()) {
1860              return false;
1861          }
1862  
1863          return $this->quba->check_file_access($slot, $options,
1864                  $component, $filearea, $args, $forcedownload);
1865      }
1866  
1867      /**
1868       * Get the navigation panel object for this attempt.
1869       *
1870       * @param mod_quiz_renderer $output the quiz renderer to use to output things.
1871       * @param string $panelclass The type of panel, quiz_attempt_nav_panel or quiz_review_nav_panel
1872       * @param int $page the current page number.
1873       * @param bool $showall whether we are showing the whole quiz on one page. (Used by review.php.)
1874       * @return block_contents the requested object.
1875       */
1876      public function get_navigation_panel(mod_quiz_renderer $output,
1877               $panelclass, $page, $showall = false) {
1878          $panel = new $panelclass($this, $this->get_display_options(true), $page, $showall);
1879  
1880          $bc = new block_contents();
1881          $bc->attributes['id'] = 'mod_quiz_navblock';
1882          $bc->attributes['role'] = 'navigation';
1883          $bc->attributes['aria-labelledby'] = 'mod_quiz_navblock_title';
1884          $bc->title = html_writer::span(get_string('quiznavigation', 'quiz'), '', array('id' => 'mod_quiz_navblock_title'));
1885          $bc->content = $output->navigation_panel($panel);
1886          return $bc;
1887      }
1888  
1889      /**
1890       * Return an array of variant URLs to other attempts at this quiz.
1891       *
1892       * The $url passed in must contain an attempt parameter.
1893       *
1894       * The {@link mod_quiz_links_to_other_attempts} object returned contains an
1895       * array with keys that are the attempt number, 1, 2, 3.
1896       * The array values are either a {@link moodle_url} with the attempt parameter
1897       * updated to point to the attempt id of the other attempt, or null corresponding
1898       * to the current attempt number.
1899       *
1900       * @param moodle_url $url a URL.
1901       * @return mod_quiz_links_to_other_attempts|bool containing array int => null|moodle_url.
1902       *      False if none.
1903       */
1904      public function links_to_other_attempts(moodle_url $url) {
1905          $attempts = quiz_get_user_attempts($this->get_quiz()->id, $this->attempt->userid, 'all');
1906          if (count($attempts) <= 1) {
1907              return false;
1908          }
1909  
1910          $links = new mod_quiz_links_to_other_attempts();
1911          foreach ($attempts as $at) {
1912              if ($at->id == $this->attempt->id) {
1913                  $links->links[$at->attempt] = null;
1914              } else {
1915                  $links->links[$at->attempt] = new moodle_url($url, array('attempt' => $at->id));
1916              }
1917          }
1918          return $links;
1919      }
1920  
1921      /**
1922       * Return an array of variant URLs to other redos of the question in a particular slot.
1923       *
1924       * The $url passed in must contain a slot parameter.
1925       *
1926       * The {@link mod_quiz_links_to_other_attempts} object returned contains an
1927       * array with keys that are the redo number, 1, 2, 3.
1928       * The array values are either a {@link moodle_url} with the slot parameter
1929       * updated to point to the slot that has that redo of this question; or null
1930       * corresponding to the redo identified by $slot.
1931       *
1932       * @param int $slot identifies a question in this attempt.
1933       * @param moodle_url $baseurl the base URL to modify to generate each link.
1934       * @return mod_quiz_links_to_other_attempts|null containing array int => null|moodle_url,
1935       *      or null if the question in this slot has not been redone.
1936       */
1937      public function links_to_other_redos($slot, moodle_url $baseurl) {
1938          $originalslot = $this->get_original_slot($slot);
1939  
1940          $qas = $this->all_question_attempts_originally_in_slot($originalslot);
1941          if (count($qas) <= 1) {
1942              return null;
1943          }
1944  
1945          $links = new mod_quiz_links_to_other_attempts();
1946          $index = 1;
1947          foreach ($qas as $qa) {
1948              if ($qa->get_slot() == $slot) {
1949                  $links->links[$index] = null;
1950              } else {
1951                  $url = new moodle_url($baseurl, array('slot' => $qa->get_slot()));
1952                  $links->links[$index] = new action_link($url, $index,
1953                          new popup_action('click', $url, 'reviewquestion',
1954                                  array('width' => 450, 'height' => 650)),
1955                          array('title' => get_string('reviewresponse', 'question')));
1956              }
1957              $index++;
1958          }
1959          return $links;
1960      }
1961  
1962      // Methods for processing ==================================================
1963  
1964      /**
1965       * Check this attempt, to see if there are any state transitions that should
1966       * happen automatically. This function will update the attempt checkstatetime.
1967       * @param int $timestamp the timestamp that should be stored as the modified
1968       * @param bool $studentisonline is the student currently interacting with Moodle?
1969       */
1970      public function handle_if_time_expired($timestamp, $studentisonline) {
1971  
1972          $timeclose = $this->get_access_manager($timestamp)->get_end_time($this->attempt);
1973  
1974          if ($timeclose === false || $this->is_preview()) {
1975              $this->update_timecheckstate(null);
1976              return; // No time limit.
1977          }
1978          if ($timestamp < $timeclose) {
1979              $this->update_timecheckstate($timeclose);
1980              return; // Time has not yet expired.
1981          }
1982  
1983          // If the attempt is already overdue, look to see if it should be abandoned ...
1984          if ($this->attempt->state == self::OVERDUE) {
1985              $timeoverdue = $timestamp - $timeclose;
1986              $graceperiod = $this->quizobj->get_quiz()->graceperiod;
1987              if ($timeoverdue >= $graceperiod) {
1988                  $this->process_abandon($timestamp, $studentisonline);
1989              } else {
1990                  // Overdue time has not yet expired
1991                  $this->update_timecheckstate($timeclose + $graceperiod);
1992              }
1993              return; // ... and we are done.
1994          }
1995  
1996          if ($this->attempt->state != self::IN_PROGRESS) {
1997              $this->update_timecheckstate(null);
1998              return; // Attempt is already in a final state.
1999          }
2000  
2001          // Otherwise, we were in quiz_attempt::IN_PROGRESS, and time has now expired.
2002          // Transition to the appropriate state.
2003          switch ($this->quizobj->get_quiz()->overduehandling) {
2004              case 'autosubmit':
2005                  $this->process_finish($timestamp, false, $studentisonline ? $timestamp : $timeclose);
2006                  return;
2007  
2008              case 'graceperiod':
2009                  $this->process_going_overdue($timestamp, $studentisonline);
2010                  return;
2011  
2012              case 'autoabandon':
2013                  $this->process_abandon($timestamp, $studentisonline);
2014                  return;
2015          }
2016  
2017          // This is an overdue attempt with no overdue handling defined, so just abandon.
2018          $this->process_abandon($timestamp, $studentisonline);
2019          return;
2020      }
2021  
2022      /**
2023       * Process all the actions that were submitted as part of the current request.
2024       *
2025       * @param int $timestamp the timestamp that should be stored as the modified.
2026       *      time in the database for these actions. If null, will use the current time.
2027       * @param bool $becomingoverdue
2028       * @param array|null $simulatedresponses If not null, then we are testing, and this is an array of simulated data.
2029       *      There are two formats supported here, for historical reasons. The newer approach is to pass an array created by
2030       *      {@link core_question_generator::get_simulated_post_data_for_questions_in_usage()}.
2031       *      the second is to pass an array slot no => contains arrays representing student
2032       *      responses which will be passed to {@link question_definition::prepare_simulated_post_data()}.
2033       *      This second method will probably get deprecated one day.
2034       */
2035      public function process_submitted_actions($timestamp, $becomingoverdue = false, $simulatedresponses = null) {
2036          global $DB;
2037  
2038          $transaction = $DB->start_delegated_transaction();
2039  
2040          if ($simulatedresponses !== null) {
2041              if (is_int(key($simulatedresponses))) {
2042                  // Legacy approach. Should be removed one day.
2043                  $simulatedpostdata = $this->quba->prepare_simulated_post_data($simulatedresponses);
2044              } else {
2045                  $simulatedpostdata = $simulatedresponses;
2046              }
2047          } else {
2048              $simulatedpostdata = null;
2049          }
2050  
2051          $this->quba->process_all_actions($timestamp, $simulatedpostdata);
2052          question_engine::save_questions_usage_by_activity($this->quba);
2053  
2054          $this->attempt->timemodified = $timestamp;
2055          if ($this->attempt->state == self::FINISHED) {
2056              $this->attempt->sumgrades = $this->quba->get_total_mark();
2057          }
2058          if ($becomingoverdue) {
2059              $this->process_going_overdue($timestamp, true);
2060          } else {
2061              $DB->update_record('quiz_attempts', $this->attempt);
2062          }
2063  
2064          if (!$this->is_preview() && $this->attempt->state == self::FINISHED) {
2065              quiz_save_best_grade($this->get_quiz(), $this->get_userid());
2066          }
2067  
2068          $transaction->allow_commit();
2069      }
2070  
2071      /**
2072       * Replace a question in an attempt with a new attempt at the same question.
2073       *
2074       * Well, for randomised questions, it won't be the same question, it will be
2075       * a different randomised selection.
2076       *
2077       * @param int $slot the question to restart.
2078       * @param int $timestamp the timestamp to record for this action.
2079       */
2080      public function process_redo_question($slot, $timestamp) {
2081          global $DB;
2082  
2083          if (!$this->can_question_be_redone_now($slot)) {
2084              throw new coding_exception('Attempt to restart the question in slot ' . $slot .
2085                      ' when it is not in a state to be restarted.');
2086          }
2087  
2088          $qubaids = new \mod_quiz\question\qubaids_for_users_attempts(
2089                  $this->get_quizid(), $this->get_userid(), 'all', true);
2090  
2091          $transaction = $DB->start_delegated_transaction();
2092  
2093          // Choose the replacement question.
2094          $questiondata = $DB->get_record('question',
2095                  array('id' => $this->slots[$slot]->questionid));
2096          if ($questiondata->qtype != 'random') {
2097              $newqusetionid = $questiondata->id;
2098          } else {
2099              $tagids = quiz_retrieve_slot_tag_ids($this->slots[$slot]->id);
2100  
2101              $randomloader = new \core_question\bank\random_question_loader($qubaids, array());
2102              $newqusetionid = $randomloader->get_next_question_id($questiondata->category,
2103                      (bool) $questiondata->questiontext, $tagids);
2104              if ($newqusetionid === null) {
2105                  throw new moodle_exception('notenoughrandomquestions', 'quiz',
2106                          $this->quizobj->view_url(), $questiondata);
2107              }
2108          }
2109  
2110          // Add the question to the usage. It is important we do this before we choose a variant.
2111          $newquestion = question_bank::load_question($newqusetionid);
2112          $newslot = $this->quba->add_question_in_place_of_other($slot, $newquestion);
2113  
2114          // Choose the variant.
2115          if ($newquestion->get_num_variants() == 1) {
2116              $variant = 1;
2117          } else {
2118              $variantstrategy = new core_question\engine\variants\least_used_strategy(
2119                      $this->quba, $qubaids);
2120              $variant = $variantstrategy->choose_variant($newquestion->get_num_variants(),
2121                      $newquestion->get_variants_selection_seed());
2122          }
2123  
2124          // Start the question.
2125          $this->quba->start_question($slot, $variant);
2126          $this->quba->set_max_mark($newslot, 0);
2127          $this->quba->set_question_attempt_metadata($newslot, 'originalslot', $slot);
2128          question_engine::save_questions_usage_by_activity($this->quba);
2129  
2130          $transaction->allow_commit();
2131      }
2132  
2133      /**
2134       * Process all the autosaved data that was part of the current request.
2135       *
2136       * @param int $timestamp the timestamp that should be stored as the modified.
2137       * time in the database for these actions. If null, will use the current time.
2138       */
2139      public function process_auto_save($timestamp) {
2140          global $DB;
2141  
2142          $transaction = $DB->start_delegated_transaction();
2143  
2144          $this->quba->process_all_autosaves($timestamp);
2145          question_engine::save_questions_usage_by_activity($this->quba);
2146  
2147          $transaction->allow_commit();
2148      }
2149  
2150      /**
2151       * Update the flagged state for all question_attempts in this usage, if their
2152       * flagged state was changed in the request.
2153       */
2154      public function save_question_flags() {
2155          global $DB;
2156  
2157          $transaction = $DB->start_delegated_transaction();
2158          $this->quba->update_question_flags();
2159          question_engine::save_questions_usage_by_activity($this->quba);
2160          $transaction->allow_commit();
2161      }
2162  
2163      /**
2164       * Submit the attempt.
2165       *
2166       * The separate $timefinish argument should be used when the quiz attempt
2167       * is being processed asynchronously (for example when cron is submitting
2168       * attempts where the time has expired).
2169       *
2170       * @param int $timestamp the time to record as last modified time.
2171       * @param bool $processsubmitted if true, and question responses in the current
2172       *      POST request are stored to be graded, before the attempt is finished.
2173       * @param ?int $timefinish if set, use this as the finish time for the attempt.
2174       *      (otherwise use $timestamp as the finish time as well).
2175       */
2176      public function process_finish($timestamp, $processsubmitted, $timefinish = null) {
2177          global $DB;
2178  
2179          $transaction = $DB->start_delegated_transaction();
2180  
2181          if ($processsubmitted) {
2182              $this->quba->process_all_actions($timestamp);
2183          }
2184          $this->quba->finish_all_questions($timestamp);
2185  
2186          question_engine::save_questions_usage_by_activity($this->quba);
2187  
2188          $this->attempt->timemodified = $timestamp;
2189          $this->attempt->timefinish = $timefinish ?? $timestamp;
2190          $this->attempt->sumgrades = $this->quba->get_total_mark();
2191          $this->attempt->state = self::FINISHED;
2192          $this->attempt->timecheckstate = null;
2193          $DB->update_record('quiz_attempts', $this->attempt);
2194  
2195          if (!$this->is_preview()) {
2196              quiz_save_best_grade($this->get_quiz(), $this->attempt->userid);
2197  
2198              // Trigger event.
2199              $this->fire_state_transition_event('\mod_quiz\event\attempt_submitted', $timestamp);
2200  
2201              // Tell any access rules that care that the attempt is over.
2202              $this->get_access_manager($timestamp)->current_attempt_finished();
2203          }
2204  
2205          $transaction->allow_commit();
2206      }
2207  
2208      /**
2209       * Update this attempt timecheckstate if necessary.
2210       *
2211       * @param int|null $time the timestamp to set.
2212       */
2213      public function update_timecheckstate($time) {
2214          global $DB;
2215          if ($this->attempt->timecheckstate !== $time) {
2216              $this->attempt->timecheckstate = $time;
2217              $DB->set_field('quiz_attempts', 'timecheckstate', $time, array('id' => $this->attempt->id));
2218          }
2219      }
2220  
2221      /**
2222       * Mark this attempt as now overdue.
2223       *
2224       * @param int $timestamp the time to deem as now.
2225       * @param bool $studentisonline is the student currently interacting with Moodle?
2226       */
2227      public function process_going_overdue($timestamp, $studentisonline) {
2228          global $DB;
2229  
2230          $transaction = $DB->start_delegated_transaction();
2231          $this->attempt->timemodified = $timestamp;
2232          $this->attempt->state = self::OVERDUE;
2233          // If we knew the attempt close time, we could compute when the graceperiod ends.
2234          // Instead we'll just fix it up through cron.
2235          $this->attempt->timecheckstate = $timestamp;
2236          $DB->update_record('quiz_attempts', $this->attempt);
2237  
2238          $this->fire_state_transition_event('\mod_quiz\event\attempt_becameoverdue', $timestamp);
2239  
2240          $transaction->allow_commit();
2241  
2242          quiz_send_overdue_message($this);
2243      }
2244  
2245      /**
2246       * Mark this attempt as abandoned.
2247       *
2248       * @param int $timestamp the time to deem as now.
2249       * @param bool $studentisonline is the student currently interacting with Moodle?
2250       */
2251      public function process_abandon($timestamp, $studentisonline) {
2252          global $DB;
2253  
2254          $transaction = $DB->start_delegated_transaction();
2255          $this->attempt->timemodified = $timestamp;
2256          $this->attempt->state = self::ABANDONED;
2257          $this->attempt->timecheckstate = null;
2258          $DB->update_record('quiz_attempts', $this->attempt);
2259  
2260          $this->fire_state_transition_event('\mod_quiz\event\attempt_abandoned', $timestamp);
2261  
2262          $transaction->allow_commit();
2263      }
2264  
2265      /**
2266       * Fire a state transition event.
2267       *
2268       * @param string $eventclass the event class name.
2269       * @param int $timestamp the timestamp to include in the event.
2270       */
2271      protected function fire_state_transition_event($eventclass, $timestamp) {
2272          global $USER;
2273          $quizrecord = $this->get_quiz();
2274          $params = array(
2275              'context' => $this->get_quizobj()->get_context(),
2276              'courseid' => $this->get_courseid(),
2277              'objectid' => $this->attempt->id,
2278              'relateduserid' => $this->attempt->userid,
2279              'other' => array(
2280                  'submitterid' => CLI_SCRIPT ? null : $USER->id,
2281                  'quizid' => $quizrecord->id
2282              )
2283          );
2284  
2285          $event = $eventclass::create($params);
2286          $event->add_record_snapshot('quiz', $this->get_quiz());
2287          $event->add_record_snapshot('quiz_attempts', $this->get_attempt());
2288          $event->trigger();
2289      }
2290  
2291      // Private methods =========================================================
2292  
2293      /**
2294       * Get a URL for a particular question on a particular page of the quiz.
2295       * Used by {@link attempt_url()} and {@link review_url()}.
2296       *
2297       * @param string $script. Used in the URL like /mod/quiz/$script.php.
2298       * @param int $slot identifies the specific question on the page to jump to.
2299       *      0 to just use the $page parameter.
2300       * @param int $page -1 to look up the page number from the slot, otherwise
2301       *      the page number to go to.
2302       * @param bool|null $showall if true, return a URL with showall=1, and not page number.
2303       *      if null, then an intelligent default will be chosen.
2304       * @param int $thispage the page we are currently on. Links to questions on this
2305       *      page will just be a fragment #q123. -1 to disable this.
2306       * @return moodle_url The requested URL.
2307       */
2308      protected function page_and_question_url($script, $slot, $page, $showall, $thispage) {
2309  
2310          $defaultshowall = $this->get_default_show_all($script);
2311          if ($showall === null && ($page == 0 || $page == -1)) {
2312              $showall = $defaultshowall;
2313          }
2314  
2315          // Fix up $page.
2316          if ($page == -1) {
2317              if ($slot !== null && !$showall) {
2318                  $page = $this->get_question_page($slot);
2319              } else {
2320                  $page = 0;
2321              }
2322          }
2323  
2324          if ($showall) {
2325              $page = 0;
2326          }
2327  
2328          // Add a fragment to scroll down to the question.
2329          $fragment = '';
2330          if ($slot !== null) {
2331              if ($slot == reset($this->pagelayout[$page])) {
2332                  // First question on page, go to top.
2333                  $fragment = '#';
2334              } else {
2335                  $qa = $this->get_question_attempt($slot);
2336                  $fragment = '#' . $qa->get_outer_question_div_unique_id();
2337              }
2338          }
2339  
2340          // Work out the correct start to the URL.
2341          if ($thispage == $page) {
2342              return new moodle_url($fragment);
2343  
2344          } else {
2345              $url = new moodle_url('/mod/quiz/' . $script . '.php' . $fragment,
2346                      array('attempt' => $this->attempt->id, 'cmid' => $this->get_cmid()));
2347              if ($page == 0 && $showall != $defaultshowall) {
2348                  $url->param('showall', (int) $showall);
2349              } else if ($page > 0) {
2350                  $url->param('page', $page);
2351              }
2352              return $url;
2353          }
2354      }
2355  
2356      /**
2357       * Process responses during an attempt at a quiz.
2358       *
2359       * @param  int $timenow time when the processing started.
2360       * @param  bool $finishattempt whether to finish the attempt or not.
2361       * @param  bool $timeup true if form was submitted by timer.
2362       * @param  int $thispage current page number.
2363       * @return string the attempt state once the data has been processed.
2364       * @since  Moodle 3.1
2365       */
2366      public function process_attempt($timenow, $finishattempt, $timeup, $thispage) {
2367          global $DB;
2368  
2369          $transaction = $DB->start_delegated_transaction();
2370  
2371          // If there is only a very small amount of time left, there is no point trying
2372          // to show the student another page of the quiz. Just finish now.
2373          $graceperiodmin = null;
2374          $accessmanager = $this->get_access_manager($timenow);
2375          $timeclose = $accessmanager->get_end_time($this->get_attempt());
2376  
2377          // Don't enforce timeclose for previews.
2378          if ($this->is_preview()) {
2379              $timeclose = false;
2380          }
2381          $toolate = false;
2382          if ($timeclose !== false && $timenow > $timeclose - QUIZ_MIN_TIME_TO_CONTINUE) {
2383              $timeup = true;
2384              $graceperiodmin = get_config('quiz', 'graceperiodmin');
2385              if ($timenow > $timeclose + $graceperiodmin) {
2386                  $toolate = true;
2387              }
2388          }
2389  
2390          // If time is running out, trigger the appropriate action.
2391          $becomingoverdue = false;
2392          $becomingabandoned = false;
2393          if ($timeup) {
2394              if ($this->get_quiz()->overduehandling == 'graceperiod') {
2395                  if (is_null($graceperiodmin)) {
2396                      $graceperiodmin = get_config('quiz', 'graceperiodmin');
2397                  }
2398                  if ($timenow > $timeclose + $this->get_quiz()->graceperiod + $graceperiodmin) {
2399                      // Grace period has run out.
2400                      $finishattempt = true;
2401                      $becomingabandoned = true;
2402                  } else {
2403                      $becomingoverdue = true;
2404                  }
2405              } else {
2406                  $finishattempt = true;
2407              }
2408          }
2409  
2410          // Don't log - we will end with a redirect to a page that is logged.
2411  
2412          if (!$finishattempt) {
2413              // Just process the responses for this page and go to the next page.
2414              if (!$toolate) {
2415                  try {
2416                      $this->process_submitted_actions($timenow, $becomingoverdue);
2417  
2418                  } catch (question_out_of_sequence_exception $e) {
2419                      throw new moodle_exception('submissionoutofsequencefriendlymessage', 'question',
2420                              $this->attempt_url(null, $thispage));
2421  
2422                  } catch (Exception $e) {
2423                      // This sucks, if we display our own custom error message, there is no way
2424                      // to display the original stack trace.
2425                      $debuginfo = '';
2426                      if (!empty($e->debuginfo)) {
2427                          $debuginfo = $e->debuginfo;
2428                      }
2429                      throw new moodle_exception('errorprocessingresponses', 'question',
2430                              $this->attempt_url(null, $thispage), $e->getMessage(), $debuginfo);
2431                  }
2432  
2433                  if (!$becomingoverdue) {
2434                      foreach ($this->get_slots() as $slot) {
2435                          if (optional_param('redoslot' . $slot, false, PARAM_BOOL)) {
2436                              $this->process_redo_question($slot, $timenow);
2437                          }
2438                      }
2439                  }
2440  
2441              } else {
2442                  // The student is too late.
2443                  $this->process_going_overdue($timenow, true);
2444              }
2445  
2446              $transaction->allow_commit();
2447  
2448              return $becomingoverdue ? self::OVERDUE : self::IN_PROGRESS;
2449          }
2450  
2451          // Update the quiz attempt record.
2452          try {
2453              if ($becomingabandoned) {
2454                  $this->process_abandon($timenow, true);
2455              } else {
2456                  $this->process_finish($timenow, !$toolate, $toolate ? $timeclose : $timenow);
2457              }
2458  
2459          } catch (question_out_of_sequence_exception $e) {
2460              throw new moodle_exception('submissionoutofsequencefriendlymessage', 'question',
2461                      $this->attempt_url(null, $thispage));
2462  
2463          } catch (Exception $e) {
2464              // This sucks, if we display our own custom error message, there is no way
2465              // to display the original stack trace.
2466              $debuginfo = '';
2467              if (!empty($e->debuginfo)) {
2468                  $debuginfo = $e->debuginfo;
2469              }
2470              throw new moodle_exception('errorprocessingresponses', 'question',
2471                      $this->attempt_url(null, $thispage), $e->getMessage(), $debuginfo);
2472          }
2473  
2474          // Send the user to the review page.
2475          $transaction->allow_commit();
2476  
2477          return $becomingabandoned ? self::ABANDONED : self::FINISHED;
2478      }
2479  
2480      /**
2481       * Check a page access to see if is an out of sequence access.
2482       *
2483       * @param  int $page page number.
2484       * @return boolean false is is an out of sequence access, true otherwise.
2485       * @since Moodle 3.1
2486       */
2487      public function check_page_access($page) {
2488          if ($this->get_currentpage() != $page) {
2489              if ($this->get_navigation_method() == QUIZ_NAVMETHOD_SEQ && $this->get_currentpage() > $page) {
2490                  return false;
2491              }
2492          }
2493          return true;
2494      }
2495  
2496      /**
2497       * Update attempt page.
2498       *
2499       * @param  int $page page number.
2500       * @return boolean true if everything was ok, false otherwise (out of sequence access).
2501       * @since Moodle 3.1
2502       */
2503      public function set_currentpage($page) {
2504          global $DB;
2505  
2506          if ($this->check_page_access($page)) {
2507              $DB->set_field('quiz_attempts', 'currentpage', $page, array('id' => $this->get_attemptid()));
2508              return true;
2509          }
2510          return false;
2511      }
2512  
2513      /**
2514       * Trigger the attempt_viewed event.
2515       *
2516       * @since Moodle 3.1
2517       */
2518      public function fire_attempt_viewed_event() {
2519          $params = array(
2520              'objectid' => $this->get_attemptid(),
2521              'relateduserid' => $this->get_userid(),
2522              'courseid' => $this->get_courseid(),
2523              'context' => context_module::instance($this->get_cmid()),
2524              'other' => array(
2525                  'quizid' => $this->get_quizid()
2526              )
2527          );
2528          $event = \mod_quiz\event\attempt_viewed::create($params);
2529          $event->add_record_snapshot('quiz_attempts', $this->get_attempt());
2530          $event->trigger();
2531      }
2532  
2533      /**
2534       * Trigger the attempt_summary_viewed event.
2535       *
2536       * @since Moodle 3.1
2537       */
2538      public function fire_attempt_summary_viewed_event() {
2539  
2540          $params = array(
2541              'objectid' => $this->get_attemptid(),
2542              'relateduserid' => $this->get_userid(),
2543              'courseid' => $this->get_courseid(),
2544              'context' => context_module::instance($this->get_cmid()),
2545              'other' => array(
2546                  'quizid' => $this->get_quizid()
2547              )
2548          );
2549          $event = \mod_quiz\event\attempt_summary_viewed::create($params);
2550          $event->add_record_snapshot('quiz_attempts', $this->get_attempt());
2551          $event->trigger();
2552      }
2553  
2554      /**
2555       * Trigger the attempt_reviewed event.
2556       *
2557       * @since Moodle 3.1
2558       */
2559      public function fire_attempt_reviewed_event() {
2560  
2561          $params = array(
2562              'objectid' => $this->get_attemptid(),
2563              'relateduserid' => $this->get_userid(),
2564              'courseid' => $this->get_courseid(),
2565              'context' => context_module::instance($this->get_cmid()),
2566              'other' => array(
2567                  'quizid' => $this->get_quizid()
2568              )
2569          );
2570          $event = \mod_quiz\event\attempt_reviewed::create($params);
2571          $event->add_record_snapshot('quiz_attempts', $this->get_attempt());
2572          $event->trigger();
2573      }
2574  
2575      /**
2576       * Update the timemodifiedoffline attempt field.
2577       *
2578       * This function should be used only when web services are being used.
2579       *
2580       * @param int $time time stamp.
2581       * @return boolean false if the field is not updated because web services aren't being used.
2582       * @since Moodle 3.2
2583       */
2584      public function set_offline_modified_time($time) {
2585          // Update the timemodifiedoffline field only if web services are being used.
2586          if (WS_SERVER) {
2587              $this->attempt->timemodifiedoffline = $time;
2588              return true;
2589          }
2590          return false;
2591      }
2592  
2593  }
2594  
2595  
2596  /**
2597   * Represents a heading in the navigation panel.
2598   *
2599   * @copyright  2015 The Open University
2600   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
2601   * @since      Moodle 2.9
2602   */
2603  class quiz_nav_section_heading implements renderable {
2604      /** @var string the heading text. */
2605      public $heading;
2606  
2607      /**
2608       * Constructor.
2609       * @param string $heading the heading text
2610       */
2611      public function __construct($heading) {
2612          $this->heading = $heading;
2613      }
2614  }
2615  
2616  
2617  /**
2618   * Represents a single link in the navigation panel.
2619   *
2620   * @copyright  2011 The Open University
2621   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
2622   * @since      Moodle 2.1
2623   */
2624  class quiz_nav_question_button implements renderable {
2625      /** @var string id="..." to add to the HTML for this button. */
2626      public $id;
2627      /** @var string number to display in this button. Either the question number of 'i'. */
2628      public $number;
2629      /** @var string class to add to the class="" attribute to represnt the question state. */
2630      public $stateclass;
2631      /** @var string Textual description of the question state, e.g. to use as a tool tip. */
2632      public $statestring;
2633      /** @var int the page number this question is on. */
2634      public $page;
2635      /** @var bool true if this question is on the current page. */
2636      public $currentpage;
2637      /** @var bool true if this question has been flagged. */
2638      public $flagged;
2639      /** @var moodle_url the link this button goes to, or null if there should not be a link. */
2640      public $url;
2641      /** @var int QUIZ_NAVMETHOD_FREE or QUIZ_NAVMETHOD_SEQ. */
2642      public $navmethod;
2643  }
2644  
2645  
2646  /**
2647   * Represents the navigation panel, and builds a {@link block_contents} to allow
2648   * it to be output.
2649   *
2650   * @copyright  2008 Tim Hunt
2651   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
2652   * @since      Moodle 2.0
2653   */
2654  abstract class quiz_nav_panel_base {
2655      /** @var quiz_attempt */
2656      protected $attemptobj;
2657      /** @var question_display_options */
2658      protected $options;
2659      /** @var integer */
2660      protected $page;
2661      /** @var boolean */
2662      protected $showall;
2663  
2664      public function __construct(quiz_attempt $attemptobj,
2665              question_display_options $options, $page, $showall) {
2666          $this->attemptobj = $attemptobj;
2667          $this->options = $options;
2668          $this->page = $page;
2669          $this->showall = $showall;
2670      }
2671  
2672      /**
2673       * Get the buttons and section headings to go in the quiz navigation block.
2674       *
2675       * @return renderable[] the buttons, possibly interleaved with section headings.
2676       */
2677      public function get_question_buttons() {
2678          $buttons = array();
2679          foreach ($this->attemptobj->get_slots() as $slot) {
2680              $heading = $this->attemptobj->get_heading_before_slot($slot);
2681              if (!is_null($heading)) {
2682                  $sections = $this->attemptobj->get_quizobj()->get_sections();
2683                  if (!(empty($heading) && count($sections) == 1)) {
2684                      $buttons[] = new quiz_nav_section_heading(format_string($heading));
2685                  }
2686              }
2687  
2688              $qa = $this->attemptobj->get_question_attempt($slot);
2689              $showcorrectness = $this->options->correctness && $qa->has_marks();
2690  
2691              $button = new quiz_nav_question_button();
2692              $button->id          = 'quiznavbutton' . $slot;
2693              $button->number      = $this->attemptobj->get_question_number($slot);
2694              $button->stateclass  = $qa->get_state_class($showcorrectness);
2695              $button->navmethod   = $this->attemptobj->get_navigation_method();
2696              if (!$showcorrectness && $button->stateclass == 'notanswered') {
2697                  $button->stateclass = 'complete';
2698              }
2699              $button->statestring = $this->get_state_string($qa, $showcorrectness);
2700              $button->page        = $this->attemptobj->get_question_page($slot);
2701              $button->currentpage = $this->showall || $button->page == $this->page;
2702              $button->flagged     = $qa->is_flagged();
2703              $button->url         = $this->get_question_url($slot);
2704              if ($this->attemptobj->is_blocked_by_previous_question($slot)) {
2705                  $button->url = null;
2706                  $button->stateclass = 'blocked';
2707                  $button->statestring = get_string('questiondependsonprevious', 'quiz');
2708              }
2709              $buttons[] = $button;
2710          }
2711  
2712          return $buttons;
2713      }
2714  
2715      protected function get_state_string(question_attempt $qa, $showcorrectness) {
2716          if ($qa->get_question(false)->length > 0) {
2717              return $qa->get_state_string($showcorrectness);
2718          }
2719  
2720          // Special case handling for 'information' items.
2721          if ($qa->get_state() == question_state::$todo) {
2722              return get_string('notyetviewed', 'quiz');
2723          } else {
2724              return get_string('viewed', 'quiz');
2725          }
2726      }
2727  
2728      /**
2729       * Hook for subclasses to override.
2730       *
2731       * @param mod_quiz_renderer $output the quiz renderer to use.
2732       * @return string HTML to output.
2733       */
2734      public function render_before_button_bits(mod_quiz_renderer $output) {
2735          return '';
2736      }
2737  
2738      abstract public function render_end_bits(mod_quiz_renderer $output);
2739  
2740      /**
2741       * Render the restart preview button.
2742       *
2743       * @param mod_quiz_renderer $output the quiz renderer to use.
2744       * @return string HTML to output.
2745       */
2746      protected function render_restart_preview_link($output) {
2747          if (!$this->attemptobj->is_own_preview()) {
2748              return '';
2749          }
2750          return $output->restart_preview_button(new moodle_url(
2751                  $this->attemptobj->start_attempt_url(), array('forcenew' => true)));
2752      }
2753  
2754      protected abstract function get_question_url($slot);
2755  
2756      public function user_picture() {
2757          global $DB;
2758          if ($this->attemptobj->get_quiz()->showuserpicture == QUIZ_SHOWIMAGE_NONE) {
2759              return null;
2760          }
2761          $user = $DB->get_record('user', array('id' => $this->attemptobj->get_userid()));
2762          $userpicture = new user_picture($user);
2763          $userpicture->courseid = $this->attemptobj->get_courseid();
2764          if ($this->attemptobj->get_quiz()->showuserpicture == QUIZ_SHOWIMAGE_LARGE) {
2765              $userpicture->size = true;
2766          }
2767          return $userpicture;
2768      }
2769  
2770      /**
2771       * Return 'allquestionsononepage' as CSS class name when $showall is set,
2772       * otherwise, return 'multipages' as CSS class name.
2773       *
2774       * @return string, CSS class name
2775       */
2776      public function get_button_container_class() {
2777          // Quiz navigation is set on 'Show all questions on one page'.
2778          if ($this->showall) {
2779              return 'allquestionsononepage';
2780          }
2781          // Quiz navigation is set on 'Show one page at a time'.
2782          return 'multipages';
2783      }
2784  }
2785  
2786  
2787  /**
2788   * Specialisation of {@link quiz_nav_panel_base} for the attempt quiz page.
2789   *
2790   * @copyright  2008 Tim Hunt
2791   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
2792   * @since      Moodle 2.0
2793   */
2794  class quiz_attempt_nav_panel extends quiz_nav_panel_base {
2795      public function get_question_url($slot) {
2796          if ($this->attemptobj->can_navigate_to($slot)) {
2797              return $this->attemptobj->attempt_url($slot, -1, $this->page);
2798          } else {
2799              return null;
2800          }
2801      }
2802  
2803      public function render_before_button_bits(mod_quiz_renderer $output) {
2804          return html_writer::tag('div', get_string('navnojswarning', 'quiz'),
2805                  array('id' => 'quiznojswarning'));
2806      }
2807  
2808      public function render_end_bits(mod_quiz_renderer $output) {
2809          if ($this->page == -1) {
2810              // Don't link from the summary page to itself.
2811              return '';
2812          }
2813          return html_writer::link($this->attemptobj->summary_url(),
2814                  get_string('endtest', 'quiz'), array('class' => 'endtestlink aalink')) .
2815                  $this->render_restart_preview_link($output);
2816      }
2817  }
2818  
2819  
2820  /**
2821   * Specialisation of {@link quiz_nav_panel_base} for the review quiz page.
2822   *
2823   * @copyright  2008 Tim Hunt
2824   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
2825   * @since      Moodle 2.0
2826   */
2827  class quiz_review_nav_panel extends quiz_nav_panel_base {
2828      public function get_question_url($slot) {
2829          return $this->attemptobj->review_url($slot, -1, $this->showall, $this->page);
2830      }
2831  
2832      public function render_end_bits(mod_quiz_renderer $output) {
2833          $html = '';
2834          if ($this->attemptobj->get_num_pages() > 1) {
2835              if ($this->showall) {
2836                  $html .= html_writer::link($this->attemptobj->review_url(null, 0, false),
2837                          get_string('showeachpage', 'quiz'));
2838              } else {
2839                  $html .= html_writer::link($this->attemptobj->review_url(null, 0, true),
2840                          get_string('showall', 'quiz'));
2841              }
2842          }
2843          $html .= $output->finish_review_link($this->attemptobj);
2844          $html .= $this->render_restart_preview_link($output);
2845          return $html;
2846      }
2847  }