[Summary view]

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

   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   * Library of functions for the quiz module.
  19   *
  20   * This contains functions that are called also from outside the quiz module
  21   * Functions that are only called by the quiz module itself are in {@link locallib.php}
  22   *
  23   * @package    mod_quiz
  24   * @copyright  1999 onwards Martin Dougiamas {@link http://moodle.com}
  25   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26   */
  27  
  28  
  29  defined('MOODLE_INTERNAL') || die();
  30  
  31  use mod_quiz\access_manager;
  32  use mod_quiz\form\add_random_form;
  33  use mod_quiz\grade_calculator;
  34  use mod_quiz\question\bank\custom_view;
  35  use mod_quiz\question\bank\qbank_helper;
  36  use mod_quiz\question\display_options;
  37  use mod_quiz\question\qubaids_for_quiz;
  38  use mod_quiz\question\qubaids_for_users_attempts;
  39  use core_question\statistics\questions\all_calculated_for_qubaid_condition;
  40  use mod_quiz\quiz_attempt;
  41  use mod_quiz\quiz_settings;
  42  
  43  require_once($CFG->dirroot . '/calendar/lib.php');
  44  
  45  /**#@+
  46   * Option controlling what options are offered on the quiz settings form.
  47   */
  48  define('QUIZ_MAX_ATTEMPT_OPTION', 10);
  49  define('QUIZ_MAX_QPP_OPTION', 50);
  50  define('QUIZ_MAX_DECIMAL_OPTION', 5);
  51  define('QUIZ_MAX_Q_DECIMAL_OPTION', 7);
  52  /**#@-*/
  53  
  54  /**#@+
  55   * Options determining how the grades from individual attempts are combined to give
  56   * the overall grade for a user
  57   */
  58  define('QUIZ_GRADEHIGHEST', '1');
  59  define('QUIZ_GRADEAVERAGE', '2');
  60  define('QUIZ_ATTEMPTFIRST', '3');
  61  define('QUIZ_ATTEMPTLAST',  '4');
  62  /**#@-*/
  63  
  64  /**
  65   * @var int If start and end date for the quiz are more than this many seconds apart
  66   * they will be represented by two separate events in the calendar
  67   */
  68  define('QUIZ_MAX_EVENT_LENGTH', 5*24*60*60); // 5 days.
  69  
  70  /**#@+
  71   * Options for navigation method within quizzes.
  72   */
  73  define('QUIZ_NAVMETHOD_FREE', 'free');
  74  define('QUIZ_NAVMETHOD_SEQ',  'sequential');
  75  /**#@-*/
  76  
  77  /**
  78   * Event types.
  79   */
  80  define('QUIZ_EVENT_TYPE_OPEN', 'open');
  81  define('QUIZ_EVENT_TYPE_CLOSE', 'close');
  82  
  83  require_once (__DIR__ . '/deprecatedlib.php');
  84  
  85  /**
  86   * Given an object containing all the necessary data,
  87   * (defined by the form in mod_form.php) this function
  88   * will create a new instance and return the id number
  89   * of the new instance.
  90   *
  91   * @param stdClass $quiz the data that came from the form.
  92   * @return mixed the id of the new instance on success,
  93   *          false or a string error message on failure.
  94   */
  95  function quiz_add_instance($quiz) {
  96      global $DB;
  97      $cmid = $quiz->coursemodule;
  98  
  99      // Process the options from the form.
 100      $quiz->timecreated = time();
 101      $result = quiz_process_options($quiz);
 102      if ($result && is_string($result)) {
 103          return $result;
 104      }
 105  
 106      // Try to store it in the database.
 107      $quiz->id = $DB->insert_record('quiz', $quiz);
 108  
 109      // Create the first section for this quiz.
 110      $DB->insert_record('quiz_sections', ['quizid' => $quiz->id,
 111              'firstslot' => 1, 'heading' => '', 'shufflequestions' => 0]);
 112  
 113      // Do the processing required after an add or an update.
 114      quiz_after_add_or_update($quiz);
 115  
 116      return $quiz->id;
 117  }
 118  
 119  /**
 120   * Given an object containing all the necessary data,
 121   * (defined by the form in mod_form.php) this function
 122   * will update an existing instance with new data.
 123   *
 124   * @param stdClass $quiz the data that came from the form.
 125   * @param stdClass $mform no longer used.
 126   * @return mixed true on success, false or a string error message on failure.
 127   */
 128  function quiz_update_instance($quiz, $mform) {
 129      global $CFG, $DB;
 130      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 131  
 132      // Process the options from the form.
 133      $result = quiz_process_options($quiz);
 134      if ($result && is_string($result)) {
 135          return $result;
 136      }
 137  
 138      // Get the current value, so we can see what changed.
 139      $oldquiz = $DB->get_record('quiz', ['id' => $quiz->instance]);
 140  
 141      // We need two values from the existing DB record that are not in the form,
 142      // in some of the function calls below.
 143      $quiz->sumgrades = $oldquiz->sumgrades;
 144      $quiz->grade     = $oldquiz->grade;
 145  
 146      // Update the database.
 147      $quiz->id = $quiz->instance;
 148      $DB->update_record('quiz', $quiz);
 149  
 150      // Do the processing required after an add or an update.
 151      quiz_after_add_or_update($quiz);
 152  
 153      if ($oldquiz->grademethod != $quiz->grademethod) {
 154          $gradecalculator = quiz_settings::create($quiz->id)->get_grade_calculator();
 155          $gradecalculator->recompute_all_final_grades();
 156          quiz_update_grades($quiz);
 157      }
 158  
 159      $quizdateschanged = $oldquiz->timelimit   != $quiz->timelimit
 160                       || $oldquiz->timeclose   != $quiz->timeclose
 161                       || $oldquiz->graceperiod != $quiz->graceperiod;
 162      if ($quizdateschanged) {
 163          quiz_update_open_attempts(['quizid' => $quiz->id]);
 164      }
 165  
 166      // Delete any previous preview attempts.
 167      quiz_delete_previews($quiz);
 168  
 169      // Repaginate, if asked to.
 170      if (!empty($quiz->repaginatenow) && !quiz_has_attempts($quiz->id)) {
 171          quiz_repaginate_questions($quiz->id, $quiz->questionsperpage);
 172      }
 173  
 174      return true;
 175  }
 176  
 177  /**
 178   * Given an ID of an instance of this module,
 179   * this function will permanently delete the instance
 180   * and any data that depends on it.
 181   *
 182   * @param int $id the id of the quiz to delete.
 183   * @return bool success or failure.
 184   */
 185  function quiz_delete_instance($id) {
 186      global $DB;
 187  
 188      $quiz = $DB->get_record('quiz', ['id' => $id], '*', MUST_EXIST);
 189  
 190      quiz_delete_all_attempts($quiz);
 191      quiz_delete_all_overrides($quiz);
 192      quiz_delete_references($quiz->id);
 193  
 194      // We need to do the following deletes before we try and delete randoms, otherwise they would still be 'in use'.
 195      $DB->delete_records('quiz_slots', ['quizid' => $quiz->id]);
 196      $DB->delete_records('quiz_sections', ['quizid' => $quiz->id]);
 197  
 198      $DB->delete_records('quiz_feedback', ['quizid' => $quiz->id]);
 199  
 200      access_manager::delete_settings($quiz);
 201  
 202      $events = $DB->get_records('event', ['modulename' => 'quiz', 'instance' => $quiz->id]);
 203      foreach ($events as $event) {
 204          $event = calendar_event::load($event);
 205          $event->delete();
 206      }
 207  
 208      quiz_grade_item_delete($quiz);
 209      // We must delete the module record after we delete the grade item.
 210      $DB->delete_records('quiz', ['id' => $quiz->id]);
 211  
 212      return true;
 213  }
 214  
 215  /**
 216   * Deletes a quiz override from the database and clears any corresponding calendar events
 217   *
 218   * @param stdClass $quiz The quiz object.
 219   * @param int $overrideid The id of the override being deleted
 220   * @param bool $log Whether to trigger logs.
 221   * @return bool true on success
 222   */
 223  function quiz_delete_override($quiz, $overrideid, $log = true) {
 224      global $DB;
 225  
 226      if (!isset($quiz->cmid)) {
 227          $cm = get_coursemodule_from_instance('quiz', $quiz->id, $quiz->course);
 228          $quiz->cmid = $cm->id;
 229      }
 230  
 231      $override = $DB->get_record('quiz_overrides', ['id' => $overrideid], '*', MUST_EXIST);
 232  
 233      // Delete the events.
 234      if (isset($override->groupid)) {
 235          // Create the search array for a group override.
 236          $eventsearcharray = ['modulename' => 'quiz',
 237              'instance' => $quiz->id, 'groupid' => (int)$override->groupid];
 238          $cachekey = "{$quiz->id}_g_{$override->groupid}";
 239      } else {
 240          // Create the search array for a user override.
 241          $eventsearcharray = ['modulename' => 'quiz',
 242              'instance' => $quiz->id, 'userid' => (int)$override->userid];
 243          $cachekey = "{$quiz->id}_u_{$override->userid}";
 244      }
 245      $events = $DB->get_records('event', $eventsearcharray);
 246      foreach ($events as $event) {
 247          $eventold = calendar_event::load($event);
 248          $eventold->delete();
 249      }
 250  
 251      $DB->delete_records('quiz_overrides', ['id' => $overrideid]);
 252      cache::make('mod_quiz', 'overrides')->delete($cachekey);
 253  
 254      if ($log) {
 255          // Set the common parameters for one of the events we will be triggering.
 256          $params = [
 257              'objectid' => $override->id,
 258              'context' => context_module::instance($quiz->cmid),
 259              'other' => [
 260                  'quizid' => $override->quiz
 261              ]
 262          ];
 263          // Determine which override deleted event to fire.
 264          if (!empty($override->userid)) {
 265              $params['relateduserid'] = $override->userid;
 266              $event = \mod_quiz\event\user_override_deleted::create($params);
 267          } else {
 268              $params['other']['groupid'] = $override->groupid;
 269              $event = \mod_quiz\event\group_override_deleted::create($params);
 270          }
 271  
 272          // Trigger the override deleted event.
 273          $event->add_record_snapshot('quiz_overrides', $override);
 274          $event->trigger();
 275      }
 276  
 277      return true;
 278  }
 279  
 280  /**
 281   * Deletes all quiz overrides from the database and clears any corresponding calendar events
 282   *
 283   * @param stdClass $quiz The quiz object.
 284   * @param bool $log Whether to trigger logs.
 285   */
 286  function quiz_delete_all_overrides($quiz, $log = true) {
 287      global $DB;
 288  
 289      $overrides = $DB->get_records('quiz_overrides', ['quiz' => $quiz->id], 'id');
 290      foreach ($overrides as $override) {
 291          quiz_delete_override($quiz, $override->id, $log);
 292      }
 293  }
 294  
 295  /**
 296   * Updates a quiz object with override information for a user.
 297   *
 298   * Algorithm:  For each quiz setting, if there is a matching user-specific override,
 299   *   then use that otherwise, if there are group-specific overrides, return the most
 300   *   lenient combination of them.  If neither applies, leave the quiz setting unchanged.
 301   *
 302   *   Special case: if there is more than one password that applies to the user, then
 303   *   quiz->extrapasswords will contain an array of strings giving the remaining
 304   *   passwords.
 305   *
 306   * @param stdClass $quiz The quiz object.
 307   * @param int $userid The userid.
 308   * @return stdClass $quiz The updated quiz object.
 309   */
 310  function quiz_update_effective_access($quiz, $userid) {
 311      global $DB;
 312  
 313      // Check for user override.
 314      $override = $DB->get_record('quiz_overrides', ['quiz' => $quiz->id, 'userid' => $userid]);
 315  
 316      if (!$override) {
 317          $override = new stdClass();
 318          $override->timeopen = null;
 319          $override->timeclose = null;
 320          $override->timelimit = null;
 321          $override->attempts = null;
 322          $override->password = null;
 323      }
 324  
 325      // Check for group overrides.
 326      $groupings = groups_get_user_groups($quiz->course, $userid);
 327  
 328      if (!empty($groupings[0])) {
 329          // Select all overrides that apply to the User's groups.
 330          list($extra, $params) = $DB->get_in_or_equal(array_values($groupings[0]));
 331          $sql = "SELECT * FROM {quiz_overrides}
 332                  WHERE groupid $extra AND quiz = ?";
 333          $params[] = $quiz->id;
 334          $records = $DB->get_records_sql($sql, $params);
 335  
 336          // Combine the overrides.
 337          $opens = [];
 338          $closes = [];
 339          $limits = [];
 340          $attempts = [];
 341          $passwords = [];
 342  
 343          foreach ($records as $gpoverride) {
 344              if (isset($gpoverride->timeopen)) {
 345                  $opens[] = $gpoverride->timeopen;
 346              }
 347              if (isset($gpoverride->timeclose)) {
 348                  $closes[] = $gpoverride->timeclose;
 349              }
 350              if (isset($gpoverride->timelimit)) {
 351                  $limits[] = $gpoverride->timelimit;
 352              }
 353              if (isset($gpoverride->attempts)) {
 354                  $attempts[] = $gpoverride->attempts;
 355              }
 356              if (isset($gpoverride->password)) {
 357                  $passwords[] = $gpoverride->password;
 358              }
 359          }
 360          // If there is a user override for a setting, ignore the group override.
 361          if (is_null($override->timeopen) && count($opens)) {
 362              $override->timeopen = min($opens);
 363          }
 364          if (is_null($override->timeclose) && count($closes)) {
 365              if (in_array(0, $closes)) {
 366                  $override->timeclose = 0;
 367              } else {
 368                  $override->timeclose = max($closes);
 369              }
 370          }
 371          if (is_null($override->timelimit) && count($limits)) {
 372              if (in_array(0, $limits)) {
 373                  $override->timelimit = 0;
 374              } else {
 375                  $override->timelimit = max($limits);
 376              }
 377          }
 378          if (is_null($override->attempts) && count($attempts)) {
 379              if (in_array(0, $attempts)) {
 380                  $override->attempts = 0;
 381              } else {
 382                  $override->attempts = max($attempts);
 383              }
 384          }
 385          if (is_null($override->password) && count($passwords)) {
 386              $override->password = array_shift($passwords);
 387              if (count($passwords)) {
 388                  $override->extrapasswords = $passwords;
 389              }
 390          }
 391  
 392      }
 393  
 394      // Merge with quiz defaults.
 395      $keys = ['timeopen', 'timeclose', 'timelimit', 'attempts', 'password', 'extrapasswords'];
 396      foreach ($keys as $key) {
 397          if (isset($override->{$key})) {
 398              $quiz->{$key} = $override->{$key};
 399          }
 400      }
 401  
 402      return $quiz;
 403  }
 404  
 405  /**
 406   * Delete all the attempts belonging to a quiz.
 407   *
 408   * @param stdClass $quiz The quiz object.
 409   */
 410  function quiz_delete_all_attempts($quiz) {
 411      global $CFG, $DB;
 412      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 413      question_engine::delete_questions_usage_by_activities(new qubaids_for_quiz($quiz->id));
 414      $DB->delete_records('quiz_attempts', ['quiz' => $quiz->id]);
 415      $DB->delete_records('quiz_grades', ['quiz' => $quiz->id]);
 416  }
 417  
 418  /**
 419   * Delete all the attempts belonging to a user in a particular quiz.
 420   *
 421   * @param \mod_quiz\quiz_settings $quiz The quiz object.
 422   * @param stdClass $user The user object.
 423   */
 424  function quiz_delete_user_attempts($quiz, $user) {
 425      global $CFG, $DB;
 426      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 427      question_engine::delete_questions_usage_by_activities(new qubaids_for_users_attempts(
 428              $quiz->get_quizid(), $user->id, 'all'));
 429      $params = [
 430          'quiz' => $quiz->get_quizid(),
 431          'userid' => $user->id,
 432      ];
 433      $DB->delete_records('quiz_attempts', $params);
 434      $DB->delete_records('quiz_grades', $params);
 435  }
 436  
 437  /**
 438   * Get the best current grade for a particular user in a quiz.
 439   *
 440   * @param stdClass $quiz the quiz settings.
 441   * @param int $userid the id of the user.
 442   * @return float the user's current grade for this quiz, or null if this user does
 443   * not have a grade on this quiz.
 444   */
 445  function quiz_get_best_grade($quiz, $userid) {
 446      global $DB;
 447      $grade = $DB->get_field('quiz_grades', 'grade',
 448              ['quiz' => $quiz->id, 'userid' => $userid]);
 449  
 450      // Need to detect errors/no result, without catching 0 grades.
 451      if ($grade === false) {
 452          return null;
 453      }
 454  
 455      return $grade + 0; // Convert to number.
 456  }
 457  
 458  /**
 459   * Is this a graded quiz? If this method returns true, you can assume that
 460   * $quiz->grade and $quiz->sumgrades are non-zero (for example, if you want to
 461   * divide by them).
 462   *
 463   * @param stdClass $quiz a row from the quiz table.
 464   * @return bool whether this is a graded quiz.
 465   */
 466  function quiz_has_grades($quiz) {
 467      return $quiz->grade >= grade_calculator::ALMOST_ZERO && $quiz->sumgrades >= grade_calculator::ALMOST_ZERO;
 468  }
 469  
 470  /**
 471   * Does this quiz allow multiple tries?
 472   *
 473   * @return bool
 474   */
 475  function quiz_allows_multiple_tries($quiz) {
 476      $bt = question_engine::get_behaviour_type($quiz->preferredbehaviour);
 477      return $bt->allows_multiple_submitted_responses();
 478  }
 479  
 480  /**
 481   * Return a small object with summary information about what a
 482   * user has done with a given particular instance of this module
 483   * Used for user activity reports.
 484   * $return->time = the time they did it
 485   * $return->info = a short text description
 486   *
 487   * @param stdClass $course
 488   * @param stdClass $user
 489   * @param stdClass $mod
 490   * @param stdClass $quiz
 491   * @return stdClass|null
 492   */
 493  function quiz_user_outline($course, $user, $mod, $quiz) {
 494      global $DB, $CFG;
 495      require_once($CFG->libdir . '/gradelib.php');
 496      $grades = grade_get_grades($course->id, 'mod', 'quiz', $quiz->id, $user->id);
 497  
 498      if (empty($grades->items[0]->grades)) {
 499          return null;
 500      } else {
 501          $grade = reset($grades->items[0]->grades);
 502      }
 503  
 504      $result = new stdClass();
 505      // If the user can't see hidden grades, don't return that information.
 506      $gitem = grade_item::fetch(['id' => $grades->items[0]->id]);
 507      if (!$gitem->hidden || has_capability('moodle/grade:viewhidden', context_course::instance($course->id))) {
 508          $result->info = get_string('gradenoun') . ': ' . $grade->str_long_grade;
 509      } else {
 510          $result->info = get_string('gradenoun') . ': ' . get_string('hidden', 'grades');
 511      }
 512  
 513      $result->time = grade_get_date_for_user_grade($grade, $user);
 514  
 515      return $result;
 516  }
 517  
 518  /**
 519   * Print a detailed representation of what a  user has done with
 520   * a given particular instance of this module, for user activity reports.
 521   *
 522   * @param stdClass $course
 523   * @param stdClass $user
 524   * @param stdClass $mod
 525   * @param stdClass $quiz
 526   * @return bool
 527   */
 528  function quiz_user_complete($course, $user, $mod, $quiz) {
 529      global $DB, $CFG, $OUTPUT;
 530      require_once($CFG->libdir . '/gradelib.php');
 531      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 532  
 533      $grades = grade_get_grades($course->id, 'mod', 'quiz', $quiz->id, $user->id);
 534      if (!empty($grades->items[0]->grades)) {
 535          $grade = reset($grades->items[0]->grades);
 536          // If the user can't see hidden grades, don't return that information.
 537          $gitem = grade_item::fetch(['id' => $grades->items[0]->id]);
 538          if (!$gitem->hidden || has_capability('moodle/grade:viewhidden', context_course::instance($course->id))) {
 539              echo $OUTPUT->container(get_string('gradenoun').': '.$grade->str_long_grade);
 540              if ($grade->str_feedback) {
 541                  echo $OUTPUT->container(get_string('feedback').': '.$grade->str_feedback);
 542              }
 543          } else {
 544              echo $OUTPUT->container(get_string('gradenoun') . ': ' . get_string('hidden', 'grades'));
 545              if ($grade->str_feedback) {
 546                  echo $OUTPUT->container(get_string('feedback').': '.get_string('hidden', 'grades'));
 547              }
 548          }
 549      }
 550  
 551      if ($attempts = $DB->get_records('quiz_attempts',
 552              ['userid' => $user->id, 'quiz' => $quiz->id], 'attempt')) {
 553          foreach ($attempts as $attempt) {
 554              echo get_string('attempt', 'quiz', $attempt->attempt) . ': ';
 555              if ($attempt->state != quiz_attempt::FINISHED) {
 556                  echo quiz_attempt_state_name($attempt->state);
 557              } else {
 558                  if (!isset($gitem)) {
 559                      if (!empty($grades->items[0]->grades)) {
 560                          $gitem = grade_item::fetch(['id' => $grades->items[0]->id]);
 561                      } else {
 562                          $gitem = new stdClass();
 563                          $gitem->hidden = true;
 564                      }
 565                  }
 566                  if (!$gitem->hidden || has_capability('moodle/grade:viewhidden', context_course::instance($course->id))) {
 567                      echo quiz_format_grade($quiz, $attempt->sumgrades) . '/' . quiz_format_grade($quiz, $quiz->sumgrades);
 568                  } else {
 569                      echo get_string('hidden', 'grades');
 570                  }
 571                  echo ' - '.userdate($attempt->timefinish).'<br />';
 572              }
 573          }
 574      } else {
 575          print_string('noattempts', 'quiz');
 576      }
 577  
 578      return true;
 579  }
 580  
 581  
 582  /**
 583   * @param int|array $quizids A quiz ID, or an array of quiz IDs.
 584   * @param int $userid the userid.
 585   * @param string $status 'all', 'finished' or 'unfinished' to control
 586   * @param bool $includepreviews
 587   * @return array of all the user's attempts at this quiz. Returns an empty
 588   *      array if there are none.
 589   */
 590  function quiz_get_user_attempts($quizids, $userid, $status = 'finished', $includepreviews = false) {
 591      global $DB;
 592  
 593      $params = [];
 594      switch ($status) {
 595          case 'all':
 596              $statuscondition = '';
 597              break;
 598  
 599          case 'finished':
 600              $statuscondition = ' AND state IN (:state1, :state2)';
 601              $params['state1'] = quiz_attempt::FINISHED;
 602              $params['state2'] = quiz_attempt::ABANDONED;
 603              break;
 604  
 605          case 'unfinished':
 606              $statuscondition = ' AND state IN (:state1, :state2)';
 607              $params['state1'] = quiz_attempt::IN_PROGRESS;
 608              $params['state2'] = quiz_attempt::OVERDUE;
 609              break;
 610      }
 611  
 612      $quizids = (array) $quizids;
 613      list($insql, $inparams) = $DB->get_in_or_equal($quizids, SQL_PARAMS_NAMED);
 614      $params += $inparams;
 615      $params['userid'] = $userid;
 616  
 617      $previewclause = '';
 618      if (!$includepreviews) {
 619          $previewclause = ' AND preview = 0';
 620      }
 621  
 622      return $DB->get_records_select('quiz_attempts',
 623              "quiz $insql AND userid = :userid" . $previewclause . $statuscondition,
 624              $params, 'quiz, attempt ASC');
 625  }
 626  
 627  /**
 628   * Return grade for given user or all users.
 629   *
 630   * @param int $quizid id of quiz
 631   * @param int $userid optional user id, 0 means all users
 632   * @return array array of grades, false if none. These are raw grades. They should
 633   * be processed with quiz_format_grade for display.
 634   */
 635  function quiz_get_user_grades($quiz, $userid = 0) {
 636      global $CFG, $DB;
 637  
 638      $params = [$quiz->id];
 639      $usertest = '';
 640      if ($userid) {
 641          $params[] = $userid;
 642          $usertest = 'AND u.id = ?';
 643      }
 644      return $DB->get_records_sql("
 645              SELECT
 646                  u.id,
 647                  u.id AS userid,
 648                  qg.grade AS rawgrade,
 649                  qg.timemodified AS dategraded,
 650                  MAX(qa.timefinish) AS datesubmitted
 651  
 652              FROM {user} u
 653              JOIN {quiz_grades} qg ON u.id = qg.userid
 654              JOIN {quiz_attempts} qa ON qa.quiz = qg.quiz AND qa.userid = u.id
 655  
 656              WHERE qg.quiz = ?
 657              $usertest
 658              GROUP BY u.id, qg.grade, qg.timemodified", $params);
 659  }
 660  
 661  /**
 662   * Round a grade to the correct number of decimal places, and format it for display.
 663   *
 664   * @param stdClass $quiz The quiz table row, only $quiz->decimalpoints is used.
 665   * @param float $grade The grade to round.
 666   * @return string
 667   */
 668  function quiz_format_grade($quiz, $grade) {
 669      if (is_null($grade)) {
 670          return get_string('notyetgraded', 'quiz');
 671      }
 672      return format_float($grade, $quiz->decimalpoints);
 673  }
 674  
 675  /**
 676   * Determine the correct number of decimal places required to format a grade.
 677   *
 678   * @param stdClass $quiz The quiz table row, only $quiz->decimalpoints and
 679   *      ->questiondecimalpoints are used.
 680   * @return integer
 681   */
 682  function quiz_get_grade_format($quiz) {
 683      if (empty($quiz->questiondecimalpoints)) {
 684          $quiz->questiondecimalpoints = -1;
 685      }
 686  
 687      if ($quiz->questiondecimalpoints == -1) {
 688          return $quiz->decimalpoints;
 689      }
 690  
 691      return $quiz->questiondecimalpoints;
 692  }
 693  
 694  /**
 695   * Round a grade to the correct number of decimal places, and format it for display.
 696   *
 697   * @param stdClass $quiz The quiz table row, only $quiz->decimalpoints is used.
 698   * @param float $grade The grade to round.
 699   * @return string
 700   */
 701  function quiz_format_question_grade($quiz, $grade) {
 702      return format_float($grade, quiz_get_grade_format($quiz));
 703  }
 704  
 705  /**
 706   * Update grades in central gradebook
 707   *
 708   * @category grade
 709   * @param stdClass $quiz the quiz settings.
 710   * @param int $userid specific user only, 0 means all users.
 711   * @param bool $nullifnone If a single user is specified and $nullifnone is true a grade item with a null rawgrade will be inserted
 712   */
 713  function quiz_update_grades($quiz, $userid = 0, $nullifnone = true) {
 714      global $CFG, $DB;
 715      require_once($CFG->libdir . '/gradelib.php');
 716  
 717      if ($quiz->grade == 0) {
 718          quiz_grade_item_update($quiz);
 719  
 720      } else if ($grades = quiz_get_user_grades($quiz, $userid)) {
 721          quiz_grade_item_update($quiz, $grades);
 722  
 723      } else if ($userid && $nullifnone) {
 724          $grade = new stdClass();
 725          $grade->userid = $userid;
 726          $grade->rawgrade = null;
 727          quiz_grade_item_update($quiz, $grade);
 728  
 729      } else {
 730          quiz_grade_item_update($quiz);
 731      }
 732  }
 733  
 734  /**
 735   * Create or update the grade item for given quiz
 736   *
 737   * @category grade
 738   * @param stdClass $quiz object with extra cmidnumber
 739   * @param mixed $grades optional array/object of grade(s); 'reset' means reset grades in gradebook
 740   * @return int 0 if ok, error code otherwise
 741   */
 742  function quiz_grade_item_update($quiz, $grades = null) {
 743      global $CFG, $OUTPUT;
 744      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 745      require_once($CFG->libdir . '/gradelib.php');
 746  
 747      if (property_exists($quiz, 'cmidnumber')) { // May not be always present.
 748          $params = ['itemname' => $quiz->name, 'idnumber' => $quiz->cmidnumber];
 749      } else {
 750          $params = ['itemname' => $quiz->name];
 751      }
 752  
 753      if ($quiz->grade > 0) {
 754          $params['gradetype'] = GRADE_TYPE_VALUE;
 755          $params['grademax']  = $quiz->grade;
 756          $params['grademin']  = 0;
 757  
 758      } else {
 759          $params['gradetype'] = GRADE_TYPE_NONE;
 760      }
 761  
 762      // What this is trying to do:
 763      // 1. If the quiz is set to not show grades while the quiz is still open,
 764      //    and is set to show grades after the quiz is closed, then create the
 765      //    grade_item with a show-after date that is the quiz close date.
 766      // 2. If the quiz is set to not show grades at either of those times,
 767      //    create the grade_item as hidden.
 768      // 3. If the quiz is set to show grades, create the grade_item visible.
 769      $openreviewoptions = display_options::make_from_quiz($quiz,
 770              display_options::LATER_WHILE_OPEN);
 771      $closedreviewoptions = display_options::make_from_quiz($quiz,
 772              display_options::AFTER_CLOSE);
 773      if ($openreviewoptions->marks < question_display_options::MARK_AND_MAX &&
 774              $closedreviewoptions->marks < question_display_options::MARK_AND_MAX) {
 775          $params['hidden'] = 1;
 776  
 777      } else if ($openreviewoptions->marks < question_display_options::MARK_AND_MAX &&
 778              $closedreviewoptions->marks >= question_display_options::MARK_AND_MAX) {
 779          if ($quiz->timeclose) {
 780              $params['hidden'] = $quiz->timeclose;
 781          } else {
 782              $params['hidden'] = 1;
 783          }
 784  
 785      } else {
 786          // Either
 787          // a) both open and closed enabled
 788          // b) open enabled, closed disabled - we can not "hide after",
 789          //    grades are kept visible even after closing.
 790          $params['hidden'] = 0;
 791      }
 792  
 793      if (!$params['hidden']) {
 794          // If the grade item is not hidden by the quiz logic, then we need to
 795          // hide it if the quiz is hidden from students.
 796          if (property_exists($quiz, 'visible')) {
 797              // Saving the quiz form, and cm not yet updated in the database.
 798              $params['hidden'] = !$quiz->visible;
 799          } else {
 800              $cm = get_coursemodule_from_instance('quiz', $quiz->id);
 801              $params['hidden'] = !$cm->visible;
 802          }
 803      }
 804  
 805      if ($grades  === 'reset') {
 806          $params['reset'] = true;
 807          $grades = null;
 808      }
 809  
 810      $gradebook_grades = grade_get_grades($quiz->course, 'mod', 'quiz', $quiz->id);
 811      if (!empty($gradebook_grades->items)) {
 812          $grade_item = $gradebook_grades->items[0];
 813          if ($grade_item->locked) {
 814              // NOTE: this is an extremely nasty hack! It is not a bug if this confirmation fails badly. --skodak.
 815              $confirm_regrade = optional_param('confirm_regrade', 0, PARAM_INT);
 816              if (!$confirm_regrade) {
 817                  if (!AJAX_SCRIPT) {
 818                      $message = get_string('gradeitemislocked', 'grades');
 819                      $back_link = $CFG->wwwroot . '/mod/quiz/report.php?q=' . $quiz->id .
 820                              '&amp;mode=overview';
 821                      $regrade_link = qualified_me() . '&amp;confirm_regrade=1';
 822                      echo $OUTPUT->box_start('generalbox', 'notice');
 823                      echo '<p>'. $message .'</p>';
 824                      echo $OUTPUT->container_start('buttons');
 825                      echo $OUTPUT->single_button($regrade_link, get_string('regradeanyway', 'grades'));
 826                      echo $OUTPUT->single_button($back_link,  get_string('cancel'));
 827                      echo $OUTPUT->container_end();
 828                      echo $OUTPUT->box_end();
 829                  }
 830                  return GRADE_UPDATE_ITEM_LOCKED;
 831              }
 832          }
 833      }
 834  
 835      return grade_update('mod/quiz', $quiz->course, 'mod', 'quiz', $quiz->id, 0, $grades, $params);
 836  }
 837  
 838  /**
 839   * Delete grade item for given quiz
 840   *
 841   * @category grade
 842   * @param stdClass $quiz object
 843   * @return int
 844   */
 845  function quiz_grade_item_delete($quiz) {
 846      global $CFG;
 847      require_once($CFG->libdir . '/gradelib.php');
 848  
 849      return grade_update('mod/quiz', $quiz->course, 'mod', 'quiz', $quiz->id, 0,
 850              null, ['deleted' => 1]);
 851  }
 852  
 853  /**
 854   * This standard function will check all instances of this module
 855   * and make sure there are up-to-date events created for each of them.
 856   * If courseid = 0, then every quiz event in the site is checked, else
 857   * only quiz events belonging to the course specified are checked.
 858   * This function is used, in its new format, by restore_refresh_events()
 859   *
 860   * @param int $courseid
 861   * @param int|stdClass $instance Quiz module instance or ID.
 862   * @param int|stdClass $cm Course module object or ID (not used in this module).
 863   * @return bool
 864   */
 865  function quiz_refresh_events($courseid = 0, $instance = null, $cm = null) {
 866      global $DB;
 867  
 868      // If we have instance information then we can just update the one event instead of updating all events.
 869      if (isset($instance)) {
 870          if (!is_object($instance)) {
 871              $instance = $DB->get_record('quiz', ['id' => $instance], '*', MUST_EXIST);
 872          }
 873          quiz_update_events($instance);
 874          return true;
 875      }
 876  
 877      if ($courseid == 0) {
 878          if (!$quizzes = $DB->get_records('quiz')) {
 879              return true;
 880          }
 881      } else {
 882          if (!$quizzes = $DB->get_records('quiz', ['course' => $courseid])) {
 883              return true;
 884          }
 885      }
 886  
 887      foreach ($quizzes as $quiz) {
 888          quiz_update_events($quiz);
 889      }
 890  
 891      return true;
 892  }
 893  
 894  /**
 895   * Returns all quiz graded users since a given time for specified quiz
 896   */
 897  function quiz_get_recent_mod_activity(&$activities, &$index, $timestart,
 898          $courseid, $cmid, $userid = 0, $groupid = 0) {
 899      global $CFG, $USER, $DB;
 900      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 901  
 902      $course = get_course($courseid);
 903      $modinfo = get_fast_modinfo($course);
 904  
 905      $cm = $modinfo->cms[$cmid];
 906      $quiz = $DB->get_record('quiz', ['id' => $cm->instance]);
 907  
 908      if ($userid) {
 909          $userselect = "AND u.id = :userid";
 910          $params['userid'] = $userid;
 911      } else {
 912          $userselect = '';
 913      }
 914  
 915      if ($groupid) {
 916          $groupselect = 'AND gm.groupid = :groupid';
 917          $groupjoin   = 'JOIN {groups_members} gm ON  gm.userid=u.id';
 918          $params['groupid'] = $groupid;
 919      } else {
 920          $groupselect = '';
 921          $groupjoin   = '';
 922      }
 923  
 924      $params['timestart'] = $timestart;
 925      $params['quizid'] = $quiz->id;
 926  
 927      $userfieldsapi = \core_user\fields::for_userpic();
 928      $ufields = $userfieldsapi->get_sql('u', false, '', 'useridagain', false)->selects;
 929      if (!$attempts = $DB->get_records_sql("
 930                SELECT qa.*,
 931                       {$ufields}
 932                  FROM {quiz_attempts} qa
 933                       JOIN {user} u ON u.id = qa.userid
 934                       $groupjoin
 935                 WHERE qa.timefinish > :timestart
 936                   AND qa.quiz = :quizid
 937                   AND qa.preview = 0
 938                       $userselect
 939                       $groupselect
 940              ORDER BY qa.timefinish ASC", $params)) {
 941          return;
 942      }
 943  
 944      $context         = context_module::instance($cm->id);
 945      $accessallgroups = has_capability('moodle/site:accessallgroups', $context);
 946      $viewfullnames   = has_capability('moodle/site:viewfullnames', $context);
 947      $grader          = has_capability('mod/quiz:viewreports', $context);
 948      $groupmode       = groups_get_activity_groupmode($cm, $course);
 949  
 950      $usersgroups = null;
 951      $aname = format_string($cm->name, true);
 952      foreach ($attempts as $attempt) {
 953          if ($attempt->userid != $USER->id) {
 954              if (!$grader) {
 955                  // Grade permission required.
 956                  continue;
 957              }
 958  
 959              if ($groupmode == SEPARATEGROUPS and !$accessallgroups) {
 960                  $usersgroups = groups_get_all_groups($course->id,
 961                          $attempt->userid, $cm->groupingid);
 962                  $usersgroups = array_keys($usersgroups);
 963                  if (!array_intersect($usersgroups, $modinfo->get_groups($cm->groupingid))) {
 964                      continue;
 965                  }
 966              }
 967          }
 968  
 969          $options = quiz_get_review_options($quiz, $attempt, $context);
 970  
 971          $tmpactivity = new stdClass();
 972  
 973          $tmpactivity->type       = 'quiz';
 974          $tmpactivity->cmid       = $cm->id;
 975          $tmpactivity->name       = $aname;
 976          $tmpactivity->sectionnum = $cm->sectionnum;
 977          $tmpactivity->timestamp  = $attempt->timefinish;
 978  
 979          $tmpactivity->content = new stdClass();
 980          $tmpactivity->content->attemptid = $attempt->id;
 981          $tmpactivity->content->attempt   = $attempt->attempt;
 982          if (quiz_has_grades($quiz) && $options->marks >= question_display_options::MARK_AND_MAX) {
 983              $tmpactivity->content->sumgrades = quiz_format_grade($quiz, $attempt->sumgrades);
 984              $tmpactivity->content->maxgrade  = quiz_format_grade($quiz, $quiz->sumgrades);
 985          } else {
 986              $tmpactivity->content->sumgrades = null;
 987              $tmpactivity->content->maxgrade  = null;
 988          }
 989  
 990          $tmpactivity->user = user_picture::unalias($attempt, null, 'useridagain');
 991          $tmpactivity->user->fullname  = fullname($tmpactivity->user, $viewfullnames);
 992  
 993          $activities[$index++] = $tmpactivity;
 994      }
 995  }
 996  
 997  function quiz_print_recent_mod_activity($activity, $courseid, $detail, $modnames) {
 998      global $CFG, $OUTPUT;
 999  
1000      echo '<table border="0" cellpadding="3" cellspacing="0" class="forum-recent">';
1001  
1002      echo '<tr><td class="userpicture" valign="top">';
1003      echo $OUTPUT->user_picture($activity->user, ['courseid' => $courseid]);
1004      echo '</td><td>';
1005  
1006      if ($detail) {
1007          $modname = $modnames[$activity->type];
1008          echo '<div class="title">';
1009          echo $OUTPUT->image_icon('monologo', $modname, $activity->type);
1010          echo '<a href="' . $CFG->wwwroot . '/mod/quiz/view.php?id=' .
1011                  $activity->cmid . '">' . $activity->name . '</a>';
1012          echo '</div>';
1013      }
1014  
1015      echo '<div class="grade">';
1016      echo  get_string('attempt', 'quiz', $activity->content->attempt);
1017      if (isset($activity->content->maxgrade)) {
1018          $grades = $activity->content->sumgrades . ' / ' . $activity->content->maxgrade;
1019          echo ': (<a href="' . $CFG->wwwroot . '/mod/quiz/review.php?attempt=' .
1020                  $activity->content->attemptid . '">' . $grades . '</a>)';
1021      }
1022      echo '</div>';
1023  
1024      echo '<div class="user">';
1025      echo '<a href="' . $CFG->wwwroot . '/user/view.php?id=' . $activity->user->id .
1026              '&amp;course=' . $courseid . '">' . $activity->user->fullname .
1027              '</a> - ' . userdate($activity->timestamp);
1028      echo '</div>';
1029  
1030      echo '</td></tr></table>';
1031  
1032      return;
1033  }
1034  
1035  /**
1036   * Pre-process the quiz options form data, making any necessary adjustments.
1037   * Called by add/update instance in this file.
1038   *
1039   * @param stdClass $quiz The variables set on the form.
1040   */
1041  function quiz_process_options($quiz) {
1042      global $CFG;
1043      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
1044      require_once($CFG->libdir . '/questionlib.php');
1045  
1046      $quiz->timemodified = time();
1047  
1048      // Quiz name.
1049      if (!empty($quiz->name)) {
1050          $quiz->name = trim($quiz->name);
1051      }
1052  
1053      // Password field - different in form to stop browsers that remember passwords
1054      // getting confused.
1055      $quiz->password = $quiz->quizpassword;
1056      unset($quiz->quizpassword);
1057  
1058      // Quiz feedback.
1059      if (isset($quiz->feedbacktext)) {
1060          // Clean up the boundary text.
1061          for ($i = 0; $i < count($quiz->feedbacktext); $i += 1) {
1062              if (empty($quiz->feedbacktext[$i]['text'])) {
1063                  $quiz->feedbacktext[$i]['text'] = '';
1064              } else {
1065                  $quiz->feedbacktext[$i]['text'] = trim($quiz->feedbacktext[$i]['text']);
1066              }
1067          }
1068  
1069          // Check the boundary value is a number or a percentage, and in range.
1070          $i = 0;
1071          while (!empty($quiz->feedbackboundaries[$i])) {
1072              $boundary = trim($quiz->feedbackboundaries[$i]);
1073              if (!is_numeric($boundary)) {
1074                  if (strlen($boundary) > 0 && $boundary[strlen($boundary) - 1] == '%') {
1075                      $boundary = trim(substr($boundary, 0, -1));
1076                      if (is_numeric($boundary)) {
1077                          $boundary = $boundary * $quiz->grade / 100.0;
1078                      } else {
1079                          return get_string('feedbackerrorboundaryformat', 'quiz', $i + 1);
1080                      }
1081                  }
1082              }
1083              if ($boundary <= 0 || $boundary >= $quiz->grade) {
1084                  return get_string('feedbackerrorboundaryoutofrange', 'quiz', $i + 1);
1085              }
1086              if ($i > 0 && $boundary >= $quiz->feedbackboundaries[$i - 1]) {
1087                  return get_string('feedbackerrororder', 'quiz', $i + 1);
1088              }
1089              $quiz->feedbackboundaries[$i] = $boundary;
1090              $i += 1;
1091          }
1092          $numboundaries = $i;
1093  
1094          // Check there is nothing in the remaining unused fields.
1095          if (!empty($quiz->feedbackboundaries)) {
1096              for ($i = $numboundaries; $i < count($quiz->feedbackboundaries); $i += 1) {
1097                  if (!empty($quiz->feedbackboundaries[$i]) &&
1098                          trim($quiz->feedbackboundaries[$i]) != '') {
1099                      return get_string('feedbackerrorjunkinboundary', 'quiz', $i + 1);
1100                  }
1101              }
1102          }
1103          for ($i = $numboundaries + 1; $i < count($quiz->feedbacktext); $i += 1) {
1104              if (!empty($quiz->feedbacktext[$i]['text']) &&
1105                      trim($quiz->feedbacktext[$i]['text']) != '') {
1106                  return get_string('feedbackerrorjunkinfeedback', 'quiz', $i + 1);
1107              }
1108          }
1109          // Needs to be bigger than $quiz->grade because of '<' test in quiz_feedback_for_grade().
1110          $quiz->feedbackboundaries[-1] = $quiz->grade + 1;
1111          $quiz->feedbackboundaries[$numboundaries] = 0;
1112          $quiz->feedbackboundarycount = $numboundaries;
1113      } else {
1114          $quiz->feedbackboundarycount = -1;
1115      }
1116  
1117      // Combing the individual settings into the review columns.
1118      $quiz->reviewattempt = quiz_review_option_form_to_db($quiz, 'attempt');
1119      $quiz->reviewcorrectness = quiz_review_option_form_to_db($quiz, 'correctness');
1120      $quiz->reviewmarks = quiz_review_option_form_to_db($quiz, 'marks');
1121      $quiz->reviewspecificfeedback = quiz_review_option_form_to_db($quiz, 'specificfeedback');
1122      $quiz->reviewgeneralfeedback = quiz_review_option_form_to_db($quiz, 'generalfeedback');
1123      $quiz->reviewrightanswer = quiz_review_option_form_to_db($quiz, 'rightanswer');
1124      $quiz->reviewoverallfeedback = quiz_review_option_form_to_db($quiz, 'overallfeedback');
1125      $quiz->reviewattempt |= display_options::DURING;
1126      $quiz->reviewoverallfeedback &= ~display_options::DURING;
1127  
1128      // Ensure that disabled checkboxes in completion settings are set to 0.
1129      // But only if the completion settinsg are unlocked.
1130      if (!empty($quiz->completionunlocked)) {
1131          if (empty($quiz->completionusegrade)) {
1132              $quiz->completionpassgrade = 0;
1133          }
1134          if (empty($quiz->completionpassgrade)) {
1135              $quiz->completionattemptsexhausted = 0;
1136          }
1137          if (empty($quiz->completionminattemptsenabled)) {
1138              $quiz->completionminattempts = 0;
1139          }
1140      }
1141  }
1142  
1143  /**
1144   * Helper function for {@link quiz_process_options()}.
1145   * @param stdClass $fromform the sumbitted form date.
1146   * @param string $field one of the review option field names.
1147   */
1148  function quiz_review_option_form_to_db($fromform, $field) {
1149      static $times = [
1150          'during' => display_options::DURING,
1151          'immediately' => display_options::IMMEDIATELY_AFTER,
1152          'open' => display_options::LATER_WHILE_OPEN,
1153          'closed' => display_options::AFTER_CLOSE,
1154      ];
1155  
1156      $review = 0;
1157      foreach ($times as $whenname => $when) {
1158          $fieldname = $field . $whenname;
1159          if (!empty($fromform->$fieldname)) {
1160              $review |= $when;
1161              unset($fromform->$fieldname);
1162          }
1163      }
1164  
1165      return $review;
1166  }
1167  
1168  /**
1169   * In place editable callback for slot displaynumber.
1170   *
1171   * @param string $itemtype slotdisplarnumber
1172   * @param int $itemid the id of the slot in the quiz_slots table
1173   * @param string $newvalue the new value for displaynumber field for a given slot in the quiz_slots table
1174   * @return \core\output\inplace_editable|void
1175   */
1176  function mod_quiz_inplace_editable(string $itemtype, int $itemid, string $newvalue): \core\output\inplace_editable {
1177      global $DB;
1178  
1179      if ($itemtype === 'slotdisplaynumber') {
1180          // Work out which quiz and slot this is.
1181          $slot = $DB->get_record('quiz_slots', ['id' => $itemid], '*', MUST_EXIST);
1182          $quizobj = quiz_settings::create($slot->quizid);
1183  
1184          // Validate the context, and check the required capability.
1185          $context = $quizobj->get_context();
1186          \core_external\external_api::validate_context($context);
1187          require_capability('mod/quiz:manage', $context);
1188  
1189          // Update the value - truncating the size of the DB column.
1190          $structure = $quizobj->get_structure();
1191          $structure->update_slot_display_number($itemid, core_text::substr($newvalue, 0, 16));
1192  
1193          // Prepare the element for the output.
1194          return $structure->make_slot_display_number_in_place_editable($itemid, $context);
1195      }
1196  }
1197  
1198  /**
1199   * This function is called at the end of quiz_add_instance
1200   * and quiz_update_instance, to do the common processing.
1201   *
1202   * @param stdClass $quiz the quiz object.
1203   */
1204  function quiz_after_add_or_update($quiz) {
1205      global $DB;
1206      $cmid = $quiz->coursemodule;
1207  
1208      // We need to use context now, so we need to make sure all needed info is already in db.
1209      $DB->set_field('course_modules', 'instance', $quiz->id, ['id' => $cmid]);
1210      $context = context_module::instance($cmid);
1211  
1212      // Save the feedback.
1213      $DB->delete_records('quiz_feedback', ['quizid' => $quiz->id]);
1214  
1215      for ($i = 0; $i <= $quiz->feedbackboundarycount; $i++) {
1216          $feedback = new stdClass();
1217          $feedback->quizid = $quiz->id;
1218          $feedback->feedbacktext = $quiz->feedbacktext[$i]['text'];
1219          $feedback->feedbacktextformat = $quiz->feedbacktext[$i]['format'];
1220          $feedback->mingrade = $quiz->feedbackboundaries[$i];
1221          $feedback->maxgrade = $quiz->feedbackboundaries[$i - 1];
1222          $feedback->id = $DB->insert_record('quiz_feedback', $feedback);
1223          $feedbacktext = file_save_draft_area_files((int)$quiz->feedbacktext[$i]['itemid'],
1224                  $context->id, 'mod_quiz', 'feedback', $feedback->id,
1225                  ['subdirs' => false, 'maxfiles' => -1, 'maxbytes' => 0],
1226                  $quiz->feedbacktext[$i]['text']);
1227          $DB->set_field('quiz_feedback', 'feedbacktext', $feedbacktext,
1228                  ['id' => $feedback->id]);
1229      }
1230  
1231      // Store any settings belonging to the access rules.
1232      access_manager::save_settings($quiz);
1233  
1234      // Update the events relating to this quiz.
1235      quiz_update_events($quiz);
1236      $completionexpected = (!empty($quiz->completionexpected)) ? $quiz->completionexpected : null;
1237      \core_completion\api::update_completion_date_event($quiz->coursemodule, 'quiz', $quiz->id, $completionexpected);
1238  
1239      // Update related grade item.
1240      quiz_grade_item_update($quiz);
1241  }
1242  
1243  /**
1244   * This function updates the events associated to the quiz.
1245   * If $override is non-zero, then it updates only the events
1246   * associated with the specified override.
1247   *
1248   * @param stdClass $quiz the quiz object.
1249   * @param stdClass|null $override limit to a specific override
1250   */
1251  function quiz_update_events($quiz, $override = null) {
1252      global $DB;
1253  
1254      // Load the old events relating to this quiz.
1255      $conds = ['modulename' => 'quiz',
1256                     'instance' => $quiz->id];
1257      if (!empty($override)) {
1258          // Only load events for this override.
1259          if (isset($override->userid)) {
1260              $conds['userid'] = $override->userid;
1261          } else {
1262              $conds['groupid'] = $override->groupid;
1263          }
1264      }
1265      $oldevents = $DB->get_records('event', $conds, 'id ASC');
1266  
1267      // Now make a to-do list of all that needs to be updated.
1268      if (empty($override)) {
1269          // We are updating the primary settings for the quiz, so we need to add all the overrides.
1270          $overrides = $DB->get_records('quiz_overrides', ['quiz' => $quiz->id], 'id ASC');
1271          // It is necessary to add an empty stdClass to the beginning of the array as the $oldevents
1272          // list contains the original (non-override) event for the module. If this is not included
1273          // the logic below will end up updating the wrong row when we try to reconcile this $overrides
1274          // list against the $oldevents list.
1275          array_unshift($overrides, new stdClass());
1276      } else {
1277          // Just do the one override.
1278          $overrides = [$override];
1279      }
1280  
1281      // Get group override priorities.
1282      $grouppriorities = quiz_get_group_override_priorities($quiz->id);
1283  
1284      foreach ($overrides as $current) {
1285          $groupid   = isset($current->groupid)?  $current->groupid : 0;
1286          $userid    = isset($current->userid)? $current->userid : 0;
1287          $timeopen  = isset($current->timeopen)?  $current->timeopen : $quiz->timeopen;
1288          $timeclose = isset($current->timeclose)? $current->timeclose : $quiz->timeclose;
1289  
1290          // Only add open/close events for an override if they differ from the quiz default.
1291          $addopen  = empty($current->id) || !empty($current->timeopen);
1292          $addclose = empty($current->id) || !empty($current->timeclose);
1293  
1294          if (!empty($quiz->coursemodule)) {
1295              $cmid = $quiz->coursemodule;
1296          } else {
1297              $cmid = get_coursemodule_from_instance('quiz', $quiz->id, $quiz->course)->id;
1298          }
1299  
1300          $event = new stdClass();
1301          $event->type = !$timeclose ? CALENDAR_EVENT_TYPE_ACTION : CALENDAR_EVENT_TYPE_STANDARD;
1302          $event->description = format_module_intro('quiz', $quiz, $cmid, false);
1303          $event->format = FORMAT_HTML;
1304          // Events module won't show user events when the courseid is nonzero.
1305          $event->courseid    = ($userid) ? 0 : $quiz->course;
1306          $event->groupid     = $groupid;
1307          $event->userid      = $userid;
1308          $event->modulename  = 'quiz';
1309          $event->instance    = $quiz->id;
1310          $event->timestart   = $timeopen;
1311          $event->timeduration = max($timeclose - $timeopen, 0);
1312          $event->timesort    = $timeopen;
1313          $event->visible     = instance_is_visible('quiz', $quiz);
1314          $event->eventtype   = QUIZ_EVENT_TYPE_OPEN;
1315          $event->priority    = null;
1316  
1317          // Determine the event name and priority.
1318          if ($groupid) {
1319              // Group override event.
1320              $params = new stdClass();
1321              $params->quiz = $quiz->name;
1322              $params->group = groups_get_group_name($groupid);
1323              if ($params->group === false) {
1324                  // Group doesn't exist, just skip it.
1325                  continue;
1326              }
1327              $eventname = get_string('overridegroupeventname', 'quiz', $params);
1328              // Set group override priority.
1329              if ($grouppriorities !== null) {
1330                  $openpriorities = $grouppriorities['open'];
1331                  if (isset($openpriorities[$timeopen])) {
1332                      $event->priority = $openpriorities[$timeopen];
1333                  }
1334              }
1335          } else if ($userid) {
1336              // User override event.
1337              $params = new stdClass();
1338              $params->quiz = $quiz->name;
1339              $eventname = get_string('overrideusereventname', 'quiz', $params);
1340              // Set user override priority.
1341              $event->priority = CALENDAR_EVENT_USER_OVERRIDE_PRIORITY;
1342          } else {
1343              // The parent event.
1344              $eventname = $quiz->name;
1345          }
1346  
1347          if ($addopen or $addclose) {
1348              // Separate start and end events.
1349              $event->timeduration  = 0;
1350              if ($timeopen && $addopen) {
1351                  if ($oldevent = array_shift($oldevents)) {
1352                      $event->id = $oldevent->id;
1353                  } else {
1354                      unset($event->id);
1355                  }
1356                  $event->name = get_string('quizeventopens', 'quiz', $eventname);
1357                  // The method calendar_event::create will reuse a db record if the id field is set.
1358                  calendar_event::create($event, false);
1359              }
1360              if ($timeclose && $addclose) {
1361                  if ($oldevent = array_shift($oldevents)) {
1362                      $event->id = $oldevent->id;
1363                  } else {
1364                      unset($event->id);
1365                  }
1366                  $event->type      = CALENDAR_EVENT_TYPE_ACTION;
1367                  $event->name      = get_string('quizeventcloses', 'quiz', $eventname);
1368                  $event->timestart = $timeclose;
1369                  $event->timesort  = $timeclose;
1370                  $event->eventtype = QUIZ_EVENT_TYPE_CLOSE;
1371                  if ($groupid && $grouppriorities !== null) {
1372                      $closepriorities = $grouppriorities['close'];
1373                      if (isset($closepriorities[$timeclose])) {
1374                          $event->priority = $closepriorities[$timeclose];
1375                      }
1376                  }
1377                  calendar_event::create($event, false);
1378              }
1379          }
1380      }
1381  
1382      // Delete any leftover events.
1383      foreach ($oldevents as $badevent) {
1384          $badevent = calendar_event::load($badevent);
1385          $badevent->delete();
1386      }
1387  }
1388  
1389  /**
1390   * Calculates the priorities of timeopen and timeclose values for group overrides for a quiz.
1391   *
1392   * @param int $quizid The quiz ID.
1393   * @return array|null Array of group override priorities for open and close times. Null if there are no group overrides.
1394   */
1395  function quiz_get_group_override_priorities($quizid) {
1396      global $DB;
1397  
1398      // Fetch group overrides.
1399      $where = 'quiz = :quiz AND groupid IS NOT NULL';
1400      $params = ['quiz' => $quizid];
1401      $overrides = $DB->get_records_select('quiz_overrides', $where, $params, '', 'id, timeopen, timeclose');
1402      if (!$overrides) {
1403          return null;
1404      }
1405  
1406      $grouptimeopen = [];
1407      $grouptimeclose = [];
1408      foreach ($overrides as $override) {
1409          if ($override->timeopen !== null && !in_array($override->timeopen, $grouptimeopen)) {
1410              $grouptimeopen[] = $override->timeopen;
1411          }
1412          if ($override->timeclose !== null && !in_array($override->timeclose, $grouptimeclose)) {
1413              $grouptimeclose[] = $override->timeclose;
1414          }
1415      }
1416  
1417      // Sort open times in ascending manner. The earlier open time gets higher priority.
1418      sort($grouptimeopen);
1419      // Set priorities.
1420      $opengrouppriorities = [];
1421      $openpriority = 1;
1422      foreach ($grouptimeopen as $timeopen) {
1423          $opengrouppriorities[$timeopen] = $openpriority++;
1424      }
1425  
1426      // Sort close times in descending manner. The later close time gets higher priority.
1427      rsort($grouptimeclose);
1428      // Set priorities.
1429      $closegrouppriorities = [];
1430      $closepriority = 1;
1431      foreach ($grouptimeclose as $timeclose) {
1432          $closegrouppriorities[$timeclose] = $closepriority++;
1433      }
1434  
1435      return [
1436          'open' => $opengrouppriorities,
1437          'close' => $closegrouppriorities
1438      ];
1439  }
1440  
1441  /**
1442   * List the actions that correspond to a view of this module.
1443   * This is used by the participation report.
1444   *
1445   * Note: This is not used by new logging system. Event with
1446   *       crud = 'r' and edulevel = LEVEL_PARTICIPATING will
1447   *       be considered as view action.
1448   *
1449   * @return array
1450   */
1451  function quiz_get_view_actions() {
1452      return ['view', 'view all', 'report', 'review'];
1453  }
1454  
1455  /**
1456   * List the actions that correspond to a post of this module.
1457   * This is used by the participation report.
1458   *
1459   * Note: This is not used by new logging system. Event with
1460   *       crud = ('c' || 'u' || 'd') and edulevel = LEVEL_PARTICIPATING
1461   *       will be considered as post action.
1462   *
1463   * @return array
1464   */
1465  function quiz_get_post_actions() {
1466      return ['attempt', 'close attempt', 'preview', 'editquestions',
1467              'delete attempt', 'manualgrade'];
1468  }
1469  
1470  /**
1471   * Standard callback used by questions_in_use.
1472   *
1473   * @param array $questionids of question ids.
1474   * @return bool whether any of these questions are used by any instance of this module.
1475   */
1476  function quiz_questions_in_use($questionids) {
1477      return question_engine::questions_in_use($questionids,
1478              new qubaid_join('{quiz_attempts} quiza', 'quiza.uniqueid',
1479                  'quiza.preview = 0'));
1480  }
1481  
1482  /**
1483   * Implementation of the function for printing the form elements that control
1484   * whether the course reset functionality affects the quiz.
1485   *
1486   * @param MoodleQuickForm $mform the course reset form that is being built.
1487   */
1488  function quiz_reset_course_form_definition($mform) {
1489      $mform->addElement('header', 'quizheader', get_string('modulenameplural', 'quiz'));
1490      $mform->addElement('advcheckbox', 'reset_quiz_attempts',
1491              get_string('removeallquizattempts', 'quiz'));
1492      $mform->addElement('advcheckbox', 'reset_quiz_user_overrides',
1493              get_string('removealluseroverrides', 'quiz'));
1494      $mform->addElement('advcheckbox', 'reset_quiz_group_overrides',
1495              get_string('removeallgroupoverrides', 'quiz'));
1496  }
1497  
1498  /**
1499   * Course reset form defaults.
1500   * @return array the defaults.
1501   */
1502  function quiz_reset_course_form_defaults($course) {
1503      return ['reset_quiz_attempts' => 1,
1504                   'reset_quiz_group_overrides' => 1,
1505                   'reset_quiz_user_overrides' => 1];
1506  }
1507  
1508  /**
1509   * Removes all grades from gradebook
1510   *
1511   * @param int $courseid
1512   * @param string optional type
1513   */
1514  function quiz_reset_gradebook($courseid, $type='') {
1515      global $CFG, $DB;
1516  
1517      $quizzes = $DB->get_records_sql("
1518              SELECT q.*, cm.idnumber as cmidnumber, q.course as courseid
1519              FROM {modules} m
1520              JOIN {course_modules} cm ON m.id = cm.module
1521              JOIN {quiz} q ON cm.instance = q.id
1522              WHERE m.name = 'quiz' AND cm.course = ?", [$courseid]);
1523  
1524      foreach ($quizzes as $quiz) {
1525          quiz_grade_item_update($quiz, 'reset');
1526      }
1527  }
1528  
1529  /**
1530   * Actual implementation of the reset course functionality, delete all the
1531   * quiz attempts for course $data->courseid, if $data->reset_quiz_attempts is
1532   * set and true.
1533   *
1534   * Also, move the quiz open and close dates, if the course start date is changing.
1535   *
1536   * @param stdClass $data the data submitted from the reset course.
1537   * @return array status array
1538   */
1539  function quiz_reset_userdata($data) {
1540      global $CFG, $DB;
1541      require_once($CFG->libdir . '/questionlib.php');
1542  
1543      $componentstr = get_string('modulenameplural', 'quiz');
1544      $status = [];
1545  
1546      // Delete attempts.
1547      if (!empty($data->reset_quiz_attempts)) {
1548          question_engine::delete_questions_usage_by_activities(new qubaid_join(
1549                  '{quiz_attempts} quiza JOIN {quiz} quiz ON quiza.quiz = quiz.id',
1550                  'quiza.uniqueid', 'quiz.course = :quizcourseid',
1551                  ['quizcourseid' => $data->courseid]));
1552  
1553          $DB->delete_records_select('quiz_attempts',
1554                  'quiz IN (SELECT id FROM {quiz} WHERE course = ?)', [$data->courseid]);
1555          $status[] = [
1556              'component' => $componentstr,
1557              'item' => get_string('attemptsdeleted', 'quiz'),
1558              'error' => false];
1559  
1560          // Remove all grades from gradebook.
1561          $DB->delete_records_select('quiz_grades',
1562                  'quiz IN (SELECT id FROM {quiz} WHERE course = ?)', [$data->courseid]);
1563          if (empty($data->reset_gradebook_grades)) {
1564              quiz_reset_gradebook($data->courseid);
1565          }
1566          $status[] = [
1567              'component' => $componentstr,
1568              'item' => get_string('gradesdeleted', 'quiz'),
1569              'error' => false];
1570      }
1571  
1572      $purgeoverrides = false;
1573  
1574      // Remove user overrides.
1575      if (!empty($data->reset_quiz_user_overrides)) {
1576          $DB->delete_records_select('quiz_overrides',
1577                  'quiz IN (SELECT id FROM {quiz} WHERE course = ?) AND userid IS NOT NULL', [$data->courseid]);
1578          $status[] = [
1579              'component' => $componentstr,
1580              'item' => get_string('useroverridesdeleted', 'quiz'),
1581              'error' => false];
1582          $purgeoverrides = true;
1583      }
1584      // Remove group overrides.
1585      if (!empty($data->reset_quiz_group_overrides)) {
1586          $DB->delete_records_select('quiz_overrides',
1587                  'quiz IN (SELECT id FROM {quiz} WHERE course = ?) AND groupid IS NOT NULL', [$data->courseid]);
1588          $status[] = [
1589              'component' => $componentstr,
1590              'item' => get_string('groupoverridesdeleted', 'quiz'),
1591              'error' => false];
1592          $purgeoverrides = true;
1593      }
1594  
1595      // Updating dates - shift may be negative too.
1596      if ($data->timeshift) {
1597          $DB->execute("UPDATE {quiz_overrides}
1598                           SET timeopen = timeopen + ?
1599                         WHERE quiz IN (SELECT id FROM {quiz} WHERE course = ?)
1600                           AND timeopen <> 0", [$data->timeshift, $data->courseid]);
1601          $DB->execute("UPDATE {quiz_overrides}
1602                           SET timeclose = timeclose + ?
1603                         WHERE quiz IN (SELECT id FROM {quiz} WHERE course = ?)
1604                           AND timeclose <> 0", [$data->timeshift, $data->courseid]);
1605  
1606          $purgeoverrides = true;
1607  
1608          // Any changes to the list of dates that needs to be rolled should be same during course restore and course reset.
1609          // See MDL-9367.
1610          shift_course_mod_dates('quiz', ['timeopen', 'timeclose'],
1611                  $data->timeshift, $data->courseid);
1612  
1613          $status[] = [
1614              'component' => $componentstr,
1615              'item' => get_string('openclosedatesupdated', 'quiz'),
1616              'error' => false];
1617      }
1618  
1619      if ($purgeoverrides) {
1620          cache::make('mod_quiz', 'overrides')->purge();
1621      }
1622  
1623      return $status;
1624  }
1625  
1626  /**
1627   * Return a textual summary of the number of attempts that have been made at a particular quiz,
1628   * returns '' if no attempts have been made yet, unless $returnzero is passed as true.
1629   *
1630   * @param stdClass $quiz the quiz object. Only $quiz->id is used at the moment.
1631   * @param stdClass $cm the cm object. Only $cm->course, $cm->groupmode and
1632   *      $cm->groupingid fields are used at the moment.
1633   * @param bool $returnzero if false (default), when no attempts have been
1634   *      made '' is returned instead of 'Attempts: 0'.
1635   * @param int $currentgroup if there is a concept of current group where this method is being called
1636   *         (e.g. a report) pass it in here. Default 0 which means no current group.
1637   * @return string a string like "Attempts: 123", "Attemtps 123 (45 from your groups)" or
1638   *          "Attemtps 123 (45 from this group)".
1639   */
1640  function quiz_num_attempt_summary($quiz, $cm, $returnzero = false, $currentgroup = 0) {
1641      global $DB, $USER;
1642      $numattempts = $DB->count_records('quiz_attempts', ['quiz' => $quiz->id, 'preview' => 0]);
1643      if ($numattempts || $returnzero) {
1644          if (groups_get_activity_groupmode($cm)) {
1645              $a = new stdClass();
1646              $a->total = $numattempts;
1647              if ($currentgroup) {
1648                  $a->group = $DB->count_records_sql('SELECT COUNT(DISTINCT qa.id) FROM ' .
1649                          '{quiz_attempts} qa JOIN ' .
1650                          '{groups_members} gm ON qa.userid = gm.userid ' .
1651                          'WHERE quiz = ? AND preview = 0 AND groupid = ?',
1652                          [$quiz->id, $currentgroup]);
1653                  return get_string('attemptsnumthisgroup', 'quiz', $a);
1654              } else if ($groups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid)) {
1655                  list($usql, $params) = $DB->get_in_or_equal(array_keys($groups));
1656                  $a->group = $DB->count_records_sql('SELECT COUNT(DISTINCT qa.id) FROM ' .
1657                          '{quiz_attempts} qa JOIN ' .
1658                          '{groups_members} gm ON qa.userid = gm.userid ' .
1659                          'WHERE quiz = ? AND preview = 0 AND ' .
1660                          "groupid $usql", array_merge([$quiz->id], $params));
1661                  return get_string('attemptsnumyourgroups', 'quiz', $a);
1662              }
1663          }
1664          return get_string('attemptsnum', 'quiz', $numattempts);
1665      }
1666      return '';
1667  }
1668  
1669  /**
1670   * Returns the same as {@link quiz_num_attempt_summary()} but wrapped in a link
1671   * to the quiz reports.
1672   *
1673   * @param stdClass $quiz the quiz object. Only $quiz->id is used at the moment.
1674   * @param stdClass $cm the cm object. Only $cm->course, $cm->groupmode and
1675   *      $cm->groupingid fields are used at the moment.
1676   * @param stdClass $context the quiz context.
1677   * @param bool $returnzero if false (default), when no attempts have been made
1678   *      '' is returned instead of 'Attempts: 0'.
1679   * @param int $currentgroup if there is a concept of current group where this method is being called
1680   *         (e.g. a report) pass it in here. Default 0 which means no current group.
1681   * @return string HTML fragment for the link.
1682   */
1683  function quiz_attempt_summary_link_to_reports($quiz, $cm, $context, $returnzero = false,
1684          $currentgroup = 0) {
1685      global $PAGE;
1686  
1687      return $PAGE->get_renderer('mod_quiz')->quiz_attempt_summary_link_to_reports(
1688              $quiz, $cm, $context, $returnzero, $currentgroup);
1689  }
1690  
1691  /**
1692   * @param string $feature FEATURE_xx constant for requested feature
1693   * @return mixed True if module supports feature, false if not, null if doesn't know or string for the module purpose.
1694   */
1695  function quiz_supports($feature) {
1696      switch($feature) {
1697          case FEATURE_GROUPS:                    return true;
1698          case FEATURE_GROUPINGS:                 return true;
1699          case FEATURE_MOD_INTRO:                 return true;
1700          case FEATURE_COMPLETION_TRACKS_VIEWS:   return true;
1701          case FEATURE_COMPLETION_HAS_RULES:      return true;
1702          case FEATURE_GRADE_HAS_GRADE:           return true;
1703          case FEATURE_GRADE_OUTCOMES:            return true;
1704          case FEATURE_BACKUP_MOODLE2:            return true;
1705          case FEATURE_SHOW_DESCRIPTION:          return true;
1706          case FEATURE_CONTROLS_GRADE_VISIBILITY: return true;
1707          case FEATURE_USES_QUESTIONS:            return true;
1708          case FEATURE_PLAGIARISM:                return true;
1709          case FEATURE_MOD_PURPOSE:               return MOD_PURPOSE_ASSESSMENT;
1710  
1711          default: return null;
1712      }
1713  }
1714  
1715  /**
1716   * @return array all other caps used in module
1717   */
1718  function quiz_get_extra_capabilities() {
1719      global $CFG;
1720      require_once($CFG->libdir . '/questionlib.php');
1721      return question_get_all_capabilities();
1722  }
1723  
1724  /**
1725   * This function extends the settings navigation block for the site.
1726   *
1727   * It is safe to rely on PAGE here as we will only ever be within the module
1728   * context when this is called
1729   *
1730   * @param settings_navigation $settings
1731   * @param navigation_node $quiznode
1732   * @return void
1733   */
1734  function quiz_extend_settings_navigation(settings_navigation $settings, navigation_node $quiznode) {
1735      global $CFG;
1736  
1737      // Require {@link questionlib.php}
1738      // Included here as we only ever want to include this file if we really need to.
1739      require_once($CFG->libdir . '/questionlib.php');
1740  
1741      // We want to add these new nodes after the Edit settings node, and before the
1742      // Locally assigned roles node. Of course, both of those are controlled by capabilities.
1743      $keys = $quiznode->get_children_key_list();
1744      $beforekey = null;
1745      $i = array_search('modedit', $keys);
1746      if ($i === false and array_key_exists(0, $keys)) {
1747          $beforekey = $keys[0];
1748      } else if (array_key_exists($i + 1, $keys)) {
1749          $beforekey = $keys[$i + 1];
1750      }
1751  
1752      if (has_any_capability(['mod/quiz:manageoverrides', 'mod/quiz:viewoverrides'], $settings->get_page()->cm->context)) {
1753          $url = new moodle_url('/mod/quiz/overrides.php', ['cmid' => $settings->get_page()->cm->id, 'mode' => 'user']);
1754          $node = navigation_node::create(get_string('overrides', 'quiz'),
1755                      $url, navigation_node::TYPE_SETTING, null, 'mod_quiz_useroverrides');
1756          $settingsoverride = $quiznode->add_node($node, $beforekey);
1757      }
1758  
1759      if (has_capability('mod/quiz:manage', $settings->get_page()->cm->context)) {
1760          $node = navigation_node::create(get_string('questions', 'quiz'),
1761              new moodle_url('/mod/quiz/edit.php', ['cmid' => $settings->get_page()->cm->id]),
1762              navigation_node::TYPE_SETTING, null, 'mod_quiz_edit', new pix_icon('t/edit', ''));
1763          $quiznode->add_node($node, $beforekey);
1764      }
1765  
1766      if (has_capability('mod/quiz:preview', $settings->get_page()->cm->context)) {
1767          $url = new moodle_url('/mod/quiz/startattempt.php',
1768                  ['cmid' => $settings->get_page()->cm->id, 'sesskey' => sesskey()]);
1769          $node = navigation_node::create(get_string('preview', 'quiz'), $url,
1770                  navigation_node::TYPE_SETTING, null, 'mod_quiz_preview',
1771                  new pix_icon('i/preview', ''));
1772          $previewnode = $quiznode->add_node($node, $beforekey);
1773          $previewnode->set_show_in_secondary_navigation(false);
1774      }
1775  
1776      question_extend_settings_navigation($quiznode, $settings->get_page()->cm->context)->trim_if_empty();
1777  
1778      if (has_any_capability(['mod/quiz:viewreports', 'mod/quiz:grade'], $settings->get_page()->cm->context)) {
1779          require_once($CFG->dirroot . '/mod/quiz/report/reportlib.php');
1780          $reportlist = quiz_report_list($settings->get_page()->cm->context);
1781  
1782          $url = new moodle_url('/mod/quiz/report.php',
1783                  ['id' => $settings->get_page()->cm->id, 'mode' => reset($reportlist)]);
1784          $reportnode = $quiznode->add_node(navigation_node::create(get_string('results', 'quiz'), $url,
1785                  navigation_node::TYPE_SETTING,
1786                  null, 'quiz_report', new pix_icon('i/report', '')));
1787  
1788          foreach ($reportlist as $report) {
1789              $url = new moodle_url('/mod/quiz/report.php', ['id' => $settings->get_page()->cm->id, 'mode' => $report]);
1790              $reportnode->add_node(navigation_node::create(get_string($report, 'quiz_'.$report), $url,
1791                      navigation_node::TYPE_SETTING,
1792                      null, 'quiz_report_' . $report, new pix_icon('i/item', '')));
1793          }
1794      }
1795  }
1796  
1797  /**
1798   * Serves the quiz files.
1799   *
1800   * @package  mod_quiz
1801   * @category files
1802   * @param stdClass $course course object
1803   * @param stdClass $cm course module object
1804   * @param stdClass $context context object
1805   * @param string $filearea file area
1806   * @param array $args extra arguments
1807   * @param bool $forcedownload whether or not force download
1808   * @param array $options additional options affecting the file serving
1809   * @return bool false if file not found, does not return if found - justsend the file
1810   */
1811  function quiz_pluginfile($course, $cm, $context, $filearea, $args, $forcedownload, array $options= []) {
1812      global $CFG, $DB;
1813  
1814      if ($context->contextlevel != CONTEXT_MODULE) {
1815          return false;
1816      }
1817  
1818      require_login($course, false, $cm);
1819  
1820      if (!$quiz = $DB->get_record('quiz', ['id' => $cm->instance])) {
1821          return false;
1822      }
1823  
1824      // The 'intro' area is served by pluginfile.php.
1825      $fileareas = ['feedback'];
1826      if (!in_array($filearea, $fileareas)) {
1827          return false;
1828      }
1829  
1830      $feedbackid = (int)array_shift($args);
1831      if (!$feedback = $DB->get_record('quiz_feedback', ['id' => $feedbackid])) {
1832          return false;
1833      }
1834  
1835      $fs = get_file_storage();
1836      $relativepath = implode('/', $args);
1837      $fullpath = "/$context->id/mod_quiz/$filearea/$feedbackid/$relativepath";
1838      if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
1839          return false;
1840      }
1841      send_stored_file($file, 0, 0, true, $options);
1842  }
1843  
1844  /**
1845   * Called via pluginfile.php -> question_pluginfile to serve files belonging to
1846   * a question in a question_attempt when that attempt is a quiz attempt.
1847   *
1848   * @package  mod_quiz
1849   * @category files
1850   * @param stdClass $course course settings object
1851   * @param stdClass $context context object
1852   * @param string $component the name of the component we are serving files for.
1853   * @param string $filearea the name of the file area.
1854   * @param int $qubaid the attempt usage id.
1855   * @param int $slot the id of a question in this quiz attempt.
1856   * @param array $args the remaining bits of the file path.
1857   * @param bool $forcedownload whether the user must be forced to download the file.
1858   * @param array $options additional options affecting the file serving
1859   * @return bool false if file not found, does not return if found - justsend the file
1860   */
1861  function quiz_question_pluginfile($course, $context, $component,
1862          $filearea, $qubaid, $slot, $args, $forcedownload, array $options= []) {
1863      global $CFG;
1864      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
1865  
1866      $attemptobj = quiz_attempt::create_from_usage_id($qubaid);
1867      require_login($attemptobj->get_course(), false, $attemptobj->get_cm());
1868  
1869      if ($attemptobj->is_own_attempt() && !$attemptobj->is_finished()) {
1870          // In the middle of an attempt.
1871          if (!$attemptobj->is_preview_user()) {
1872              $attemptobj->require_capability('mod/quiz:attempt');
1873          }
1874          $isreviewing = false;
1875  
1876      } else {
1877          // Reviewing an attempt.
1878          $attemptobj->check_review_capability();
1879          $isreviewing = true;
1880      }
1881  
1882      if (!$attemptobj->check_file_access($slot, $isreviewing, $context->id,
1883              $component, $filearea, $args, $forcedownload)) {
1884          send_file_not_found();
1885      }
1886  
1887      $fs = get_file_storage();
1888      $relativepath = implode('/', $args);
1889      $fullpath = "/$context->id/$component/$filearea/$relativepath";
1890      if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
1891          send_file_not_found();
1892      }
1893  
1894      send_stored_file($file, 0, 0, $forcedownload, $options);
1895  }
1896  
1897  /**
1898   * Return a list of page types
1899   * @param string $pagetype current page type
1900   * @param stdClass $parentcontext Block's parent context
1901   * @param stdClass $currentcontext Current context of block
1902   */
1903  function quiz_page_type_list($pagetype, $parentcontext, $currentcontext) {
1904      $modulepagetype = [
1905          'mod-quiz-*'       => get_string('page-mod-quiz-x', 'quiz'),
1906          'mod-quiz-view'    => get_string('page-mod-quiz-view', 'quiz'),
1907          'mod-quiz-attempt' => get_string('page-mod-quiz-attempt', 'quiz'),
1908          'mod-quiz-summary' => get_string('page-mod-quiz-summary', 'quiz'),
1909          'mod-quiz-review'  => get_string('page-mod-quiz-review', 'quiz'),
1910          'mod-quiz-edit'    => get_string('page-mod-quiz-edit', 'quiz'),
1911          'mod-quiz-report'  => get_string('page-mod-quiz-report', 'quiz'),
1912      ];
1913      return $modulepagetype;
1914  }
1915  
1916  /**
1917   * @return the options for quiz navigation.
1918   */
1919  function quiz_get_navigation_options() {
1920      return [
1921          QUIZ_NAVMETHOD_FREE => get_string('navmethod_free', 'quiz'),
1922          QUIZ_NAVMETHOD_SEQ  => get_string('navmethod_seq', 'quiz')
1923      ];
1924  }
1925  
1926  /**
1927   * Check if the module has any update that affects the current user since a given time.
1928   *
1929   * @param  cm_info $cm course module data
1930   * @param  int $from the time to check updates from
1931   * @param  array $filter  if we need to check only specific updates
1932   * @return stdClass an object with the different type of areas indicating if they were updated or not
1933   * @since Moodle 3.2
1934   */
1935  function quiz_check_updates_since(cm_info $cm, $from, $filter = []) {
1936      global $DB, $USER, $CFG;
1937      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
1938  
1939      $updates = course_check_module_updates_since($cm, $from, [], $filter);
1940  
1941      // Check if questions were updated.
1942      $updates->questions = (object) ['updated' => false];
1943      $quizobj = quiz_settings::create($cm->instance, $USER->id);
1944      $quizobj->preload_questions();
1945      $quizobj->load_questions();
1946      $questionids = array_keys($quizobj->get_questions());
1947      if (!empty($questionids)) {
1948          list($questionsql, $params) = $DB->get_in_or_equal($questionids, SQL_PARAMS_NAMED);
1949          $select = 'id ' . $questionsql . ' AND (timemodified > :time1 OR timecreated > :time2)';
1950          $params['time1'] = $from;
1951          $params['time2'] = $from;
1952          $questions = $DB->get_records_select('question', $select, $params, '', 'id');
1953          if (!empty($questions)) {
1954              $updates->questions->updated = true;
1955              $updates->questions->itemids = array_keys($questions);
1956          }
1957      }
1958  
1959      // Check for new attempts or grades.
1960      $updates->attempts = (object) ['updated' => false];
1961      $updates->grades = (object) ['updated' => false];
1962      $select = 'quiz = ? AND userid = ? AND timemodified > ?';
1963      $params = [$cm->instance, $USER->id, $from];
1964  
1965      $attempts = $DB->get_records_select('quiz_attempts', $select, $params, '', 'id');
1966      if (!empty($attempts)) {
1967          $updates->attempts->updated = true;
1968          $updates->attempts->itemids = array_keys($attempts);
1969      }
1970      $grades = $DB->get_records_select('quiz_grades', $select, $params, '', 'id');
1971      if (!empty($grades)) {
1972          $updates->grades->updated = true;
1973          $updates->grades->itemids = array_keys($grades);
1974      }
1975  
1976      // Now, teachers should see other students updates.
1977      if (has_capability('mod/quiz:viewreports', $cm->context)) {
1978          $select = 'quiz = ? AND timemodified > ?';
1979          $params = [$cm->instance, $from];
1980  
1981          if (groups_get_activity_groupmode($cm) == SEPARATEGROUPS) {
1982              $groupusers = array_keys(groups_get_activity_shared_group_members($cm));
1983              if (empty($groupusers)) {
1984                  return $updates;
1985              }
1986              list($insql, $inparams) = $DB->get_in_or_equal($groupusers);
1987              $select .= ' AND userid ' . $insql;
1988              $params = array_merge($params, $inparams);
1989          }
1990  
1991          $updates->userattempts = (object) ['updated' => false];
1992          $attempts = $DB->get_records_select('quiz_attempts', $select, $params, '', 'id');
1993          if (!empty($attempts)) {
1994              $updates->userattempts->updated = true;
1995              $updates->userattempts->itemids = array_keys($attempts);
1996          }
1997  
1998          $updates->usergrades = (object) ['updated' => false];
1999          $grades = $DB->get_records_select('quiz_grades', $select, $params, '', 'id');
2000          if (!empty($grades)) {
2001              $updates->usergrades->updated = true;
2002              $updates->usergrades->itemids = array_keys($grades);
2003          }
2004      }
2005      return $updates;
2006  }
2007  
2008  /**
2009   * Get icon mapping for font-awesome.
2010   */
2011  function mod_quiz_get_fontawesome_icon_map() {
2012      return [
2013          'mod_quiz:navflagged' => 'fa-flag',
2014      ];
2015  }
2016  
2017  /**
2018   * This function receives a calendar event and returns the action associated with it, or null if there is none.
2019   *
2020   * This is used by block_myoverview in order to display the event appropriately. If null is returned then the event
2021   * is not displayed on the block.
2022   *
2023   * @param calendar_event $event
2024   * @param \core_calendar\action_factory $factory
2025   * @param int $userid User id to use for all capability checks, etc. Set to 0 for current user (default).
2026   * @return \core_calendar\local\event\entities\action_interface|null
2027   */
2028  function mod_quiz_core_calendar_provide_event_action(calendar_event $event,
2029                                                       \core_calendar\action_factory $factory,
2030                                                       int $userid = 0) {
2031      global $CFG, $USER;
2032  
2033      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
2034  
2035      if (empty($userid)) {
2036          $userid = $USER->id;
2037      }
2038  
2039      $cm = get_fast_modinfo($event->courseid, $userid)->instances['quiz'][$event->instance];
2040      $quizobj = quiz_settings::create($cm->instance, $userid);
2041      $quiz = $quizobj->get_quiz();
2042  
2043      // Check they have capabilities allowing them to view the quiz.
2044      if (!has_any_capability(['mod/quiz:reviewmyattempts', 'mod/quiz:attempt'], $quizobj->get_context(), $userid)) {
2045          return null;
2046      }
2047  
2048      $completion = new \completion_info($cm->get_course());
2049  
2050      $completiondata = $completion->get_data($cm, false, $userid);
2051  
2052      if ($completiondata->completionstate != COMPLETION_INCOMPLETE) {
2053          return null;
2054      }
2055  
2056      quiz_update_effective_access($quiz, $userid);
2057  
2058      // Check if quiz is closed, if so don't display it.
2059      if (!empty($quiz->timeclose) && $quiz->timeclose <= time()) {
2060          return null;
2061      }
2062  
2063      if (!$quizobj->is_participant($userid)) {
2064          // If the user is not a participant then they have
2065          // no action to take. This will filter out the events for teachers.
2066          return null;
2067      }
2068  
2069      $attempts = quiz_get_user_attempts($quizobj->get_quizid(), $userid);
2070      if (!empty($attempts)) {
2071          // The student's last attempt is finished.
2072          return null;
2073      }
2074  
2075      $name = get_string('attemptquiznow', 'quiz');
2076      $url = new \moodle_url('/mod/quiz/view.php', [
2077          'id' => $cm->id
2078      ]);
2079      $itemcount = 1;
2080      $actionable = true;
2081  
2082      // Check if the quiz is not currently actionable.
2083      if (!empty($quiz->timeopen) && $quiz->timeopen > time()) {
2084          $actionable = false;
2085      }
2086  
2087      return $factory->create_instance(
2088          $name,
2089          $url,
2090          $itemcount,
2091          $actionable
2092      );
2093  }
2094  
2095  /**
2096   * Add a get_coursemodule_info function in case any quiz type wants to add 'extra' information
2097   * for the course (see resource).
2098   *
2099   * Given a course_module object, this function returns any "extra" information that may be needed
2100   * when printing this activity in a course listing.  See get_array_of_activities() in course/lib.php.
2101   *
2102   * @param stdClass $coursemodule The coursemodule object (record).
2103   * @return cached_cm_info|false An object on information that the courses
2104   *                        will know about (most noticeably, an icon).
2105   */
2106  function quiz_get_coursemodule_info($coursemodule) {
2107      global $DB;
2108  
2109      $dbparams = ['id' => $coursemodule->instance];
2110      $fields = 'id, name, intro, introformat, completionattemptsexhausted, completionminattempts,
2111          timeopen, timeclose';
2112      if (!$quiz = $DB->get_record('quiz', $dbparams, $fields)) {
2113          return false;
2114      }
2115  
2116      $result = new cached_cm_info();
2117      $result->name = $quiz->name;
2118  
2119      if ($coursemodule->showdescription) {
2120          // Convert intro to html. Do not filter cached version, filters run at display time.
2121          $result->content = format_module_intro('quiz', $quiz, $coursemodule->id, false);
2122      }
2123  
2124      // Populate the custom completion rules as key => value pairs, but only if the completion mode is 'automatic'.
2125      if ($coursemodule->completion == COMPLETION_TRACKING_AUTOMATIC) {
2126          if ($quiz->completionattemptsexhausted) {
2127              $result->customdata['customcompletionrules']['completionpassorattemptsexhausted'] = [
2128                  'completionpassgrade' => $coursemodule->completionpassgrade,
2129                  'completionattemptsexhausted' => $quiz->completionattemptsexhausted,
2130              ];
2131          } else {
2132              $result->customdata['customcompletionrules']['completionpassorattemptsexhausted'] = [];
2133          }
2134  
2135          $result->customdata['customcompletionrules']['completionminattempts'] = $quiz->completionminattempts;
2136      }
2137  
2138      // Populate some other values that can be used in calendar or on dashboard.
2139      if ($quiz->timeopen) {
2140          $result->customdata['timeopen'] = $quiz->timeopen;
2141      }
2142      if ($quiz->timeclose) {
2143          $result->customdata['timeclose'] = $quiz->timeclose;
2144      }
2145  
2146      return $result;
2147  }
2148  
2149  /**
2150   * Sets dynamic information about a course module
2151   *
2152   * This function is called from cm_info when displaying the module
2153   *
2154   * @param cm_info $cm
2155   */
2156  function mod_quiz_cm_info_dynamic(cm_info $cm) {
2157      global $USER;
2158  
2159      $cache = cache::make('mod_quiz', 'overrides');
2160      $override = $cache->get("{$cm->instance}_u_{$USER->id}");
2161  
2162      if (!$override) {
2163          $override = (object) [
2164              'timeopen' => null,
2165              'timeclose' => null,
2166          ];
2167      }
2168  
2169      // No need to look for group overrides if there are user overrides for both timeopen and timeclose.
2170      if (is_null($override->timeopen) || is_null($override->timeclose)) {
2171          $opens = [];
2172          $closes = [];
2173          $groupings = groups_get_user_groups($cm->course, $USER->id);
2174          foreach ($groupings[0] as $groupid) {
2175              $groupoverride = $cache->get("{$cm->instance}_g_{$groupid}");
2176              if (isset($groupoverride->timeopen)) {
2177                  $opens[] = $groupoverride->timeopen;
2178              }
2179              if (isset($groupoverride->timeclose)) {
2180                  $closes[] = $groupoverride->timeclose;
2181              }
2182          }
2183          // If there is a user override for a setting, ignore the group override.
2184          if (is_null($override->timeopen) && count($opens)) {
2185              $override->timeopen = min($opens);
2186          }
2187          if (is_null($override->timeclose) && count($closes)) {
2188              if (in_array(0, $closes)) {
2189                  $override->timeclose = 0;
2190              } else {
2191                  $override->timeclose = max($closes);
2192              }
2193          }
2194      }
2195  
2196      // Populate some other values that can be used in calendar or on dashboard.
2197      if (!is_null($override->timeopen)) {
2198          $cm->override_customdata('timeopen', $override->timeopen);
2199      }
2200      if (!is_null($override->timeclose)) {
2201          $cm->override_customdata('timeclose', $override->timeclose);
2202      }
2203  }
2204  
2205  /**
2206   * Callback which returns human-readable strings describing the active completion custom rules for the module instance.
2207   *
2208   * @param cm_info|stdClass $cm object with fields ->completion and ->customdata['customcompletionrules']
2209   * @return array $descriptions the array of descriptions for the custom rules.
2210   */
2211  function mod_quiz_get_completion_active_rule_descriptions($cm) {
2212      // Values will be present in cm_info, and we assume these are up to date.
2213      if (empty($cm->customdata['customcompletionrules'])
2214          || $cm->completion != COMPLETION_TRACKING_AUTOMATIC) {
2215          return [];
2216      }
2217  
2218      $descriptions = [];
2219      $rules = $cm->customdata['customcompletionrules'];
2220  
2221      if (!empty($rules['completionpassorattemptsexhausted'])) {
2222          if (!empty($rules['completionpassorattemptsexhausted']['completionattemptsexhausted'])) {
2223              $descriptions[] = get_string('completionpassorattemptsexhausteddesc', 'quiz');
2224          }
2225      } else {
2226          // Fallback.
2227          if (!empty($rules['completionattemptsexhausted'])) {
2228              $descriptions[] = get_string('completionpassorattemptsexhausteddesc', 'quiz');
2229          }
2230      }
2231  
2232      if (!empty($rules['completionminattempts'])) {
2233          $descriptions[] = get_string('completionminattemptsdesc', 'quiz', $rules['completionminattempts']);
2234      }
2235  
2236      return $descriptions;
2237  }
2238  
2239  /**
2240   * Returns the min and max values for the timestart property of a quiz
2241   * activity event.
2242   *
2243   * The min and max values will be the timeopen and timeclose properties
2244   * of the quiz, respectively, if they are set.
2245   *
2246   * If either value isn't set then null will be returned instead to
2247   * indicate that there is no cutoff for that value.
2248   *
2249   * If the vent has no valid timestart range then [false, false] will
2250   * be returned. This is the case for overriden events.
2251   *
2252   * A minimum and maximum cutoff return value will look like:
2253   * [
2254   *     [1505704373, 'The date must be after this date'],
2255   *     [1506741172, 'The date must be before this date']
2256   * ]
2257   *
2258   * @throws \moodle_exception
2259   * @param \calendar_event $event The calendar event to get the time range for
2260   * @param stdClass $quiz The module instance to get the range from
2261   * @return array
2262   */
2263  function mod_quiz_core_calendar_get_valid_event_timestart_range(\calendar_event $event, \stdClass $quiz) {
2264      global $CFG, $DB;
2265      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
2266  
2267      // Overrides do not have a valid timestart range.
2268      if (quiz_is_overriden_calendar_event($event)) {
2269          return [false, false];
2270      }
2271  
2272      $mindate = null;
2273      $maxdate = null;
2274  
2275      if ($event->eventtype == QUIZ_EVENT_TYPE_OPEN) {
2276          if (!empty($quiz->timeclose)) {
2277              $maxdate = [
2278                  $quiz->timeclose,
2279                  get_string('openafterclose', 'quiz')
2280              ];
2281          }
2282      } else if ($event->eventtype == QUIZ_EVENT_TYPE_CLOSE) {
2283          if (!empty($quiz->timeopen)) {
2284              $mindate = [
2285                  $quiz->timeopen,
2286                  get_string('closebeforeopen', 'quiz')
2287              ];
2288          }
2289      }
2290  
2291      return [$mindate, $maxdate];
2292  }
2293  
2294  /**
2295   * This function will update the quiz module according to the
2296   * event that has been modified.
2297   *
2298   * It will set the timeopen or timeclose value of the quiz instance
2299   * according to the type of event provided.
2300   *
2301   * @throws \moodle_exception
2302   * @param \calendar_event $event A quiz activity calendar event
2303   * @param \stdClass $quiz A quiz activity instance
2304   */
2305  function mod_quiz_core_calendar_event_timestart_updated(\calendar_event $event, \stdClass $quiz) {
2306      global $CFG, $DB;
2307      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
2308  
2309      if (!in_array($event->eventtype, [QUIZ_EVENT_TYPE_OPEN, QUIZ_EVENT_TYPE_CLOSE])) {
2310          // This isn't an event that we care about so we can ignore it.
2311          return;
2312      }
2313  
2314      $courseid = $event->courseid;
2315      $modulename = $event->modulename;
2316      $instanceid = $event->instance;
2317      $modified = false;
2318      $closedatechanged = false;
2319  
2320      // Something weird going on. The event is for a different module so
2321      // we should ignore it.
2322      if ($modulename != 'quiz') {
2323          return;
2324      }
2325  
2326      if ($quiz->id != $instanceid) {
2327          // The provided quiz instance doesn't match the event so
2328          // there is nothing to do here.
2329          return;
2330      }
2331  
2332      // We don't update the activity if it's an override event that has
2333      // been modified.
2334      if (quiz_is_overriden_calendar_event($event)) {
2335          return;
2336      }
2337  
2338      $coursemodule = get_fast_modinfo($courseid)->instances[$modulename][$instanceid];
2339      $context = context_module::instance($coursemodule->id);
2340  
2341      // The user does not have the capability to modify this activity.
2342      if (!has_capability('moodle/course:manageactivities', $context)) {
2343          return;
2344      }
2345  
2346      if ($event->eventtype == QUIZ_EVENT_TYPE_OPEN) {
2347          // If the event is for the quiz activity opening then we should
2348          // set the start time of the quiz activity to be the new start
2349          // time of the event.
2350          if ($quiz->timeopen != $event->timestart) {
2351              $quiz->timeopen = $event->timestart;
2352              $modified = true;
2353          }
2354      } else if ($event->eventtype == QUIZ_EVENT_TYPE_CLOSE) {
2355          // If the event is for the quiz activity closing then we should
2356          // set the end time of the quiz activity to be the new start
2357          // time of the event.
2358          if ($quiz->timeclose != $event->timestart) {
2359              $quiz->timeclose = $event->timestart;
2360              $modified = true;
2361              $closedatechanged = true;
2362          }
2363      }
2364  
2365      if ($modified) {
2366          $quiz->timemodified = time();
2367          $DB->update_record('quiz', $quiz);
2368  
2369          if ($closedatechanged) {
2370              quiz_update_open_attempts(['quizid' => $quiz->id]);
2371          }
2372  
2373          // Delete any previous preview attempts.
2374          quiz_delete_previews($quiz);
2375          quiz_update_events($quiz);
2376          $event = \core\event\course_module_updated::create_from_cm($coursemodule, $context);
2377          $event->trigger();
2378      }
2379  }
2380  
2381  /**
2382   * Generates the question bank in a fragment output. This allows
2383   * the question bank to be displayed in a modal.
2384   *
2385   * The only expected argument provided in the $args array is
2386   * 'querystring'. The value should be the list of parameters
2387   * URL encoded and used to build the question bank page.
2388   *
2389   * The individual list of parameters expected can be found in
2390   * question_build_edit_resources.
2391   *
2392   * @param array $args The fragment arguments.
2393   * @return string The rendered mform fragment.
2394   */
2395  function mod_quiz_output_fragment_quiz_question_bank($args) {
2396      global $CFG, $DB, $PAGE;
2397      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
2398      require_once($CFG->dirroot . '/question/editlib.php');
2399  
2400      $querystring = preg_replace('/^\?/', '', $args['querystring']);
2401      $params = [];
2402      parse_str($querystring, $params);
2403  
2404      // Build the required resources. The $params are all cleaned as
2405      // part of this process.
2406      list($thispageurl, $contexts, $cmid, $cm, $quiz, $pagevars) =
2407              question_build_edit_resources('editq', '/mod/quiz/edit.php', $params, custom_view::DEFAULT_PAGE_SIZE);
2408  
2409      // Get the course object and related bits.
2410      $course = get_course($quiz->course);
2411      require_capability('mod/quiz:manage', $contexts->lowest());
2412  
2413      // Create quiz question bank view.
2414      $questionbank = new custom_view($contexts, $thispageurl, $course, $cm, $quiz);
2415      $questionbank->set_quiz_has_attempts(quiz_has_attempts($quiz->id));
2416  
2417      // Output.
2418      $renderer = $PAGE->get_renderer('mod_quiz', 'edit');
2419      return $renderer->question_bank_contents($questionbank, $pagevars);
2420  }
2421  
2422  /**
2423   * Generates the add random question in a fragment output. This allows the
2424   * form to be rendered in javascript, for example inside a modal.
2425   *
2426   * The required arguments as keys in the $args array are:
2427   *      cat {string} The category and category context ids comma separated.
2428   *      addonpage {int} The page id to add this question to.
2429   *      returnurl {string} URL to return to after form submission.
2430   *      cmid {int} The course module id the questions are being added to.
2431   *
2432   * @param array $args The fragment arguments.
2433   * @return string The rendered mform fragment.
2434   */
2435  function mod_quiz_output_fragment_add_random_question_form($args) {
2436      global $CFG;
2437  
2438      $contexts = new \core_question\local\bank\question_edit_contexts($args['context']);
2439      $formoptions = [
2440          'contexts' => $contexts,
2441          'cat' => $args['cat']
2442      ];
2443      $formdata = [
2444          'category' => $args['cat'],
2445          'addonpage' => $args['addonpage'],
2446          'returnurl' => $args['returnurl'],
2447          'cmid' => $args['cmid']
2448      ];
2449  
2450      $form = new add_random_form(
2451          new \moodle_url('/mod/quiz/addrandom.php'),
2452          $formoptions,
2453          'post',
2454          '',
2455          null,
2456          true,
2457          $formdata
2458      );
2459      $form->set_data($formdata);
2460  
2461      return $form->render();
2462  }
2463  
2464  /**
2465   * Callback to fetch the activity event type lang string.
2466   *
2467   * @param string $eventtype The event type.
2468   * @return lang_string The event type lang string.
2469   */
2470  function mod_quiz_core_calendar_get_event_action_string(string $eventtype): string {
2471      $modulename = get_string('modulename', 'quiz');
2472  
2473      switch ($eventtype) {
2474          case QUIZ_EVENT_TYPE_OPEN:
2475              $identifier = 'quizeventopens';
2476              break;
2477          case QUIZ_EVENT_TYPE_CLOSE:
2478              $identifier = 'quizeventcloses';
2479              break;
2480          default:
2481              return get_string('requiresaction', 'calendar', $modulename);
2482      }
2483  
2484      return get_string($identifier, 'quiz', $modulename);
2485  }
2486  
2487  /**
2488   * Delete question reference data.
2489   *
2490   * @param int $quizid The id of quiz.
2491   */
2492  function quiz_delete_references($quizid): void {
2493      global $DB;
2494      $slots = $DB->get_records('quiz_slots', ['quizid' => $quizid]);
2495      foreach ($slots as $slot) {
2496          $params = [
2497              'itemid' => $slot->id,
2498              'component' => 'mod_quiz',
2499              'questionarea' => 'slot'
2500          ];
2501          // Delete any set references.
2502          $DB->delete_records('question_set_references', $params);
2503          // Delete any references.
2504          $DB->delete_records('question_references', $params);
2505      }
2506  }
2507  
2508  /**
2509   * Implement the calculate_question_stats callback.
2510   *
2511   * This enables quiz statistics to be shown in statistics columns in the database.
2512   *
2513   * @param context $context return the statistics related to this context (which will be a quiz context).
2514   * @return all_calculated_for_qubaid_condition|null The statistics for this quiz, if available, else null.
2515   */
2516  function mod_quiz_calculate_question_stats(context $context): ?all_calculated_for_qubaid_condition {
2517      global $CFG;
2518      require_once($CFG->dirroot . '/mod/quiz/report/statistics/report.php');
2519      $cm = get_coursemodule_from_id('quiz', $context->instanceid);
2520      $report = new quiz_statistics_report();
2521      return $report->calculate_questions_stats_for_question_bank($cm->instance, false, false);
2522  }