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Differences Between: [Versions 310 and 400] [Versions 311 and 400] [Versions 39 and 400] [Versions 400 and 401] [Versions 400 and 402] [Versions 400 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 core_question\statistics\questions\all_calculated_for_qubaid_condition;
  32  
  33  require_once($CFG->dirroot . '/calendar/lib.php');
  34  
  35  
  36  /**#@+
  37   * Option controlling what options are offered on the quiz settings form.
  38   */
  39  define('QUIZ_MAX_ATTEMPT_OPTION', 10);
  40  define('QUIZ_MAX_QPP_OPTION', 50);
  41  define('QUIZ_MAX_DECIMAL_OPTION', 5);
  42  define('QUIZ_MAX_Q_DECIMAL_OPTION', 7);
  43  /**#@-*/
  44  
  45  /**#@+
  46   * Options determining how the grades from individual attempts are combined to give
  47   * the overall grade for a user
  48   */
  49  define('QUIZ_GRADEHIGHEST', '1');
  50  define('QUIZ_GRADEAVERAGE', '2');
  51  define('QUIZ_ATTEMPTFIRST', '3');
  52  define('QUIZ_ATTEMPTLAST',  '4');
  53  /**#@-*/
  54  
  55  /**
  56   * @var int If start and end date for the quiz are more than this many seconds apart
  57   * they will be represented by two separate events in the calendar
  58   */
  59  define('QUIZ_MAX_EVENT_LENGTH', 5*24*60*60); // 5 days.
  60  
  61  /**#@+
  62   * Options for navigation method within quizzes.
  63   */
  64  define('QUIZ_NAVMETHOD_FREE', 'free');
  65  define('QUIZ_NAVMETHOD_SEQ',  'sequential');
  66  /**#@-*/
  67  
  68  /**
  69   * Event types.
  70   */
  71  define('QUIZ_EVENT_TYPE_OPEN', 'open');
  72  define('QUIZ_EVENT_TYPE_CLOSE', 'close');
  73  
  74  require_once (__DIR__ . '/deprecatedlib.php');
  75  
  76  /**
  77   * Given an object containing all the necessary data,
  78   * (defined by the form in mod_form.php) this function
  79   * will create a new instance and return the id number
  80   * of the new instance.
  81   *
  82   * @param object $quiz the data that came from the form.
  83   * @return mixed the id of the new instance on success,
  84   *          false or a string error message on failure.
  85   */
  86  function quiz_add_instance($quiz) {
  87      global $DB;
  88      $cmid = $quiz->coursemodule;
  89  
  90      // Process the options from the form.
  91      $quiz->timecreated = time();
  92      $result = quiz_process_options($quiz);
  93      if ($result && is_string($result)) {
  94          return $result;
  95      }
  96  
  97      // Try to store it in the database.
  98      $quiz->id = $DB->insert_record('quiz', $quiz);
  99  
 100      // Create the first section for this quiz.
 101      $DB->insert_record('quiz_sections', array('quizid' => $quiz->id,
 102              'firstslot' => 1, 'heading' => '', 'shufflequestions' => 0));
 103  
 104      // Do the processing required after an add or an update.
 105      quiz_after_add_or_update($quiz);
 106  
 107      return $quiz->id;
 108  }
 109  
 110  /**
 111   * Given an object containing all the necessary data,
 112   * (defined by the form in mod_form.php) this function
 113   * will update an existing instance with new data.
 114   *
 115   * @param object $quiz the data that came from the form.
 116   * @return mixed true on success, false or a string error message on failure.
 117   */
 118  function quiz_update_instance($quiz, $mform) {
 119      global $CFG, $DB;
 120      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 121  
 122      // Process the options from the form.
 123      $result = quiz_process_options($quiz);
 124      if ($result && is_string($result)) {
 125          return $result;
 126      }
 127  
 128      // Get the current value, so we can see what changed.
 129      $oldquiz = $DB->get_record('quiz', array('id' => $quiz->instance));
 130  
 131      // We need two values from the existing DB record that are not in the form,
 132      // in some of the function calls below.
 133      $quiz->sumgrades = $oldquiz->sumgrades;
 134      $quiz->grade     = $oldquiz->grade;
 135  
 136      // Update the database.
 137      $quiz->id = $quiz->instance;
 138      $DB->update_record('quiz', $quiz);
 139  
 140      // Do the processing required after an add or an update.
 141      quiz_after_add_or_update($quiz);
 142  
 143      if ($oldquiz->grademethod != $quiz->grademethod) {
 144          quiz_update_all_final_grades($quiz);
 145          quiz_update_grades($quiz);
 146      }
 147  
 148      $quizdateschanged = $oldquiz->timelimit   != $quiz->timelimit
 149                       || $oldquiz->timeclose   != $quiz->timeclose
 150                       || $oldquiz->graceperiod != $quiz->graceperiod;
 151      if ($quizdateschanged) {
 152          quiz_update_open_attempts(array('quizid' => $quiz->id));
 153      }
 154  
 155      // Delete any previous preview attempts.
 156      quiz_delete_previews($quiz);
 157  
 158      // Repaginate, if asked to.
 159      if (!empty($quiz->repaginatenow) && !quiz_has_attempts($quiz->id)) {
 160          quiz_repaginate_questions($quiz->id, $quiz->questionsperpage);
 161      }
 162  
 163      return true;
 164  }
 165  
 166  /**
 167   * Given an ID of an instance of this module,
 168   * this function will permanently delete the instance
 169   * and any data that depends on it.
 170   *
 171   * @param int $id the id of the quiz to delete.
 172   * @return bool success or failure.
 173   */
 174  function quiz_delete_instance($id) {
 175      global $DB;
 176  
 177      $quiz = $DB->get_record('quiz', array('id' => $id), '*', MUST_EXIST);
 178  
 179      quiz_delete_all_attempts($quiz);
 180      quiz_delete_all_overrides($quiz);
 181      quiz_delete_references($quiz->id);
 182  
 183      // We need to do the following deletes before we try and delete randoms, otherwise they would still be 'in use'.
 184      $DB->delete_records('quiz_slots', array('quizid' => $quiz->id));
 185      $DB->delete_records('quiz_sections', array('quizid' => $quiz->id));
 186  
 187      $DB->delete_records('quiz_feedback', array('quizid' => $quiz->id));
 188  
 189      quiz_access_manager::delete_settings($quiz);
 190  
 191      $events = $DB->get_records('event', array('modulename' => 'quiz', 'instance' => $quiz->id));
 192      foreach ($events as $event) {
 193          $event = calendar_event::load($event);
 194          $event->delete();
 195      }
 196  
 197      quiz_grade_item_delete($quiz);
 198      // We must delete the module record after we delete the grade item.
 199      $DB->delete_records('quiz', array('id' => $quiz->id));
 200  
 201      return true;
 202  }
 203  
 204  /**
 205   * Deletes a quiz override from the database and clears any corresponding calendar events
 206   *
 207   * @param object $quiz The quiz object.
 208   * @param int $overrideid The id of the override being deleted
 209   * @param bool $log Whether to trigger logs.
 210   * @return bool true on success
 211   */
 212  function quiz_delete_override($quiz, $overrideid, $log = true) {
 213      global $DB;
 214  
 215      if (!isset($quiz->cmid)) {
 216          $cm = get_coursemodule_from_instance('quiz', $quiz->id, $quiz->course);
 217          $quiz->cmid = $cm->id;
 218      }
 219  
 220      $override = $DB->get_record('quiz_overrides', array('id' => $overrideid), '*', MUST_EXIST);
 221  
 222      // Delete the events.
 223      if (isset($override->groupid)) {
 224          // Create the search array for a group override.
 225          $eventsearcharray = array('modulename' => 'quiz',
 226              'instance' => $quiz->id, 'groupid' => (int)$override->groupid);
 227          $cachekey = "{$quiz->id}_g_{$override->groupid}";
 228      } else {
 229          // Create the search array for a user override.
 230          $eventsearcharray = array('modulename' => 'quiz',
 231              'instance' => $quiz->id, 'userid' => (int)$override->userid);
 232          $cachekey = "{$quiz->id}_u_{$override->userid}";
 233      }
 234      $events = $DB->get_records('event', $eventsearcharray);
 235      foreach ($events as $event) {
 236          $eventold = calendar_event::load($event);
 237          $eventold->delete();
 238      }
 239  
 240      $DB->delete_records('quiz_overrides', array('id' => $overrideid));
 241      cache::make('mod_quiz', 'overrides')->delete($cachekey);
 242  
 243      if ($log) {
 244          // Set the common parameters for one of the events we will be triggering.
 245          $params = array(
 246              'objectid' => $override->id,
 247              'context' => context_module::instance($quiz->cmid),
 248              'other' => array(
 249                  'quizid' => $override->quiz
 250              )
 251          );
 252          // Determine which override deleted event to fire.
 253          if (!empty($override->userid)) {
 254              $params['relateduserid'] = $override->userid;
 255              $event = \mod_quiz\event\user_override_deleted::create($params);
 256          } else {
 257              $params['other']['groupid'] = $override->groupid;
 258              $event = \mod_quiz\event\group_override_deleted::create($params);
 259          }
 260  
 261          // Trigger the override deleted event.
 262          $event->add_record_snapshot('quiz_overrides', $override);
 263          $event->trigger();
 264      }
 265  
 266      return true;
 267  }
 268  
 269  /**
 270   * Deletes all quiz overrides from the database and clears any corresponding calendar events
 271   *
 272   * @param object $quiz The quiz object.
 273   * @param bool $log Whether to trigger logs.
 274   */
 275  function quiz_delete_all_overrides($quiz, $log = true) {
 276      global $DB;
 277  
 278      $overrides = $DB->get_records('quiz_overrides', array('quiz' => $quiz->id), 'id');
 279      foreach ($overrides as $override) {
 280          quiz_delete_override($quiz, $override->id, $log);
 281      }
 282  }
 283  
 284  /**
 285   * Updates a quiz object with override information for a user.
 286   *
 287   * Algorithm:  For each quiz setting, if there is a matching user-specific override,
 288   *   then use that otherwise, if there are group-specific overrides, return the most
 289   *   lenient combination of them.  If neither applies, leave the quiz setting unchanged.
 290   *
 291   *   Special case: if there is more than one password that applies to the user, then
 292   *   quiz->extrapasswords will contain an array of strings giving the remaining
 293   *   passwords.
 294   *
 295   * @param object $quiz The quiz object.
 296   * @param int $userid The userid.
 297   * @return object $quiz The updated quiz object.
 298   */
 299  function quiz_update_effective_access($quiz, $userid) {
 300      global $DB;
 301  
 302      // Check for user override.
 303      $override = $DB->get_record('quiz_overrides', array('quiz' => $quiz->id, 'userid' => $userid));
 304  
 305      if (!$override) {
 306          $override = new stdClass();
 307          $override->timeopen = null;
 308          $override->timeclose = null;
 309          $override->timelimit = null;
 310          $override->attempts = null;
 311          $override->password = null;
 312      }
 313  
 314      // Check for group overrides.
 315      $groupings = groups_get_user_groups($quiz->course, $userid);
 316  
 317      if (!empty($groupings[0])) {
 318          // Select all overrides that apply to the User's groups.
 319          list($extra, $params) = $DB->get_in_or_equal(array_values($groupings[0]));
 320          $sql = "SELECT * FROM {quiz_overrides}
 321                  WHERE groupid $extra AND quiz = ?";
 322          $params[] = $quiz->id;
 323          $records = $DB->get_records_sql($sql, $params);
 324  
 325          // Combine the overrides.
 326          $opens = array();
 327          $closes = array();
 328          $limits = array();
 329          $attempts = array();
 330          $passwords = array();
 331  
 332          foreach ($records as $gpoverride) {
 333              if (isset($gpoverride->timeopen)) {
 334                  $opens[] = $gpoverride->timeopen;
 335              }
 336              if (isset($gpoverride->timeclose)) {
 337                  $closes[] = $gpoverride->timeclose;
 338              }
 339              if (isset($gpoverride->timelimit)) {
 340                  $limits[] = $gpoverride->timelimit;
 341              }
 342              if (isset($gpoverride->attempts)) {
 343                  $attempts[] = $gpoverride->attempts;
 344              }
 345              if (isset($gpoverride->password)) {
 346                  $passwords[] = $gpoverride->password;
 347              }
 348          }
 349          // If there is a user override for a setting, ignore the group override.
 350          if (is_null($override->timeopen) && count($opens)) {
 351              $override->timeopen = min($opens);
 352          }
 353          if (is_null($override->timeclose) && count($closes)) {
 354              if (in_array(0, $closes)) {
 355                  $override->timeclose = 0;
 356              } else {
 357                  $override->timeclose = max($closes);
 358              }
 359          }
 360          if (is_null($override->timelimit) && count($limits)) {
 361              if (in_array(0, $limits)) {
 362                  $override->timelimit = 0;
 363              } else {
 364                  $override->timelimit = max($limits);
 365              }
 366          }
 367          if (is_null($override->attempts) && count($attempts)) {
 368              if (in_array(0, $attempts)) {
 369                  $override->attempts = 0;
 370              } else {
 371                  $override->attempts = max($attempts);
 372              }
 373          }
 374          if (is_null($override->password) && count($passwords)) {
 375              $override->password = array_shift($passwords);
 376              if (count($passwords)) {
 377                  $override->extrapasswords = $passwords;
 378              }
 379          }
 380  
 381      }
 382  
 383      // Merge with quiz defaults.
 384      $keys = array('timeopen', 'timeclose', 'timelimit', 'attempts', 'password', 'extrapasswords');
 385      foreach ($keys as $key) {
 386          if (isset($override->{$key})) {
 387              $quiz->{$key} = $override->{$key};
 388          }
 389      }
 390  
 391      return $quiz;
 392  }
 393  
 394  /**
 395   * Delete all the attempts belonging to a quiz.
 396   *
 397   * @param object $quiz The quiz object.
 398   */
 399  function quiz_delete_all_attempts($quiz) {
 400      global $CFG, $DB;
 401      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 402      question_engine::delete_questions_usage_by_activities(new qubaids_for_quiz($quiz->id));
 403      $DB->delete_records('quiz_attempts', array('quiz' => $quiz->id));
 404      $DB->delete_records('quiz_grades', array('quiz' => $quiz->id));
 405  }
 406  
 407  /**
 408   * Delete all the attempts belonging to a user in a particular quiz.
 409   *
 410   * @param object $quiz The quiz object.
 411   * @param object $user The user object.
 412   */
 413  function quiz_delete_user_attempts($quiz, $user) {
 414      global $CFG, $DB;
 415      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 416      question_engine::delete_questions_usage_by_activities(new qubaids_for_quiz_user($quiz->get_quizid(), $user->id));
 417      $params = [
 418          'quiz' => $quiz->get_quizid(),
 419          'userid' => $user->id,
 420      ];
 421      $DB->delete_records('quiz_attempts', $params);
 422      $DB->delete_records('quiz_grades', $params);
 423  }
 424  
 425  /**
 426   * Get the best current grade for a particular user in a quiz.
 427   *
 428   * @param object $quiz the quiz settings.
 429   * @param int $userid the id of the user.
 430   * @return float the user's current grade for this quiz, or null if this user does
 431   * not have a grade on this quiz.
 432   */
 433  function quiz_get_best_grade($quiz, $userid) {
 434      global $DB;
 435      $grade = $DB->get_field('quiz_grades', 'grade',
 436              array('quiz' => $quiz->id, 'userid' => $userid));
 437  
 438      // Need to detect errors/no result, without catching 0 grades.
 439      if ($grade === false) {
 440          return null;
 441      }
 442  
 443      return $grade + 0; // Convert to number.
 444  }
 445  
 446  /**
 447   * Is this a graded quiz? If this method returns true, you can assume that
 448   * $quiz->grade and $quiz->sumgrades are non-zero (for example, if you want to
 449   * divide by them).
 450   *
 451   * @param object $quiz a row from the quiz table.
 452   * @return bool whether this is a graded quiz.
 453   */
 454  function quiz_has_grades($quiz) {
 455      return $quiz->grade >= 0.000005 && $quiz->sumgrades >= 0.000005;
 456  }
 457  
 458  /**
 459   * Does this quiz allow multiple tries?
 460   *
 461   * @return bool
 462   */
 463  function quiz_allows_multiple_tries($quiz) {
 464      $bt = question_engine::get_behaviour_type($quiz->preferredbehaviour);
 465      return $bt->allows_multiple_submitted_responses();
 466  }
 467  
 468  /**
 469   * Return a small object with summary information about what a
 470   * user has done with a given particular instance of this module
 471   * Used for user activity reports.
 472   * $return->time = the time they did it
 473   * $return->info = a short text description
 474   *
 475   * @param object $course
 476   * @param object $user
 477   * @param object $mod
 478   * @param object $quiz
 479   * @return object|null
 480   */
 481  function quiz_user_outline($course, $user, $mod, $quiz) {
 482      global $DB, $CFG;
 483      require_once($CFG->libdir . '/gradelib.php');
 484      $grades = grade_get_grades($course->id, 'mod', 'quiz', $quiz->id, $user->id);
 485  
 486      if (empty($grades->items[0]->grades)) {
 487          return null;
 488      } else {
 489          $grade = reset($grades->items[0]->grades);
 490      }
 491  
 492      $result = new stdClass();
 493      // If the user can't see hidden grades, don't return that information.
 494      $gitem = grade_item::fetch(array('id' => $grades->items[0]->id));
 495      if (!$gitem->hidden || has_capability('moodle/grade:viewhidden', context_course::instance($course->id))) {
 496          $result->info = get_string('gradenoun') . ': ' . $grade->str_long_grade;
 497      } else {
 498          $result->info = get_string('gradenoun') . ': ' . get_string('hidden', 'grades');
 499      }
 500  
 501      $result->time = grade_get_date_for_user_grade($grade, $user);
 502  
 503      return $result;
 504  }
 505  
 506  /**
 507   * Print a detailed representation of what a  user has done with
 508   * a given particular instance of this module, for user activity reports.
 509   *
 510   * @param object $course
 511   * @param object $user
 512   * @param object $mod
 513   * @param object $quiz
 514   * @return bool
 515   */
 516  function quiz_user_complete($course, $user, $mod, $quiz) {
 517      global $DB, $CFG, $OUTPUT;
 518      require_once($CFG->libdir . '/gradelib.php');
 519      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 520  
 521      $grades = grade_get_grades($course->id, 'mod', 'quiz', $quiz->id, $user->id);
 522      if (!empty($grades->items[0]->grades)) {
 523          $grade = reset($grades->items[0]->grades);
 524          // If the user can't see hidden grades, don't return that information.
 525          $gitem = grade_item::fetch(array('id' => $grades->items[0]->id));
 526          if (!$gitem->hidden || has_capability('moodle/grade:viewhidden', context_course::instance($course->id))) {
 527              echo $OUTPUT->container(get_string('gradenoun').': '.$grade->str_long_grade);
 528              if ($grade->str_feedback) {
 529                  echo $OUTPUT->container(get_string('feedback').': '.$grade->str_feedback);
 530              }
 531          } else {
 532              echo $OUTPUT->container(get_string('gradenoun') . ': ' . get_string('hidden', 'grades'));
 533              if ($grade->str_feedback) {
 534                  echo $OUTPUT->container(get_string('feedback').': '.get_string('hidden', 'grades'));
 535              }
 536          }
 537      }
 538  
 539      if ($attempts = $DB->get_records('quiz_attempts',
 540              array('userid' => $user->id, 'quiz' => $quiz->id), 'attempt')) {
 541          foreach ($attempts as $attempt) {
 542              echo get_string('attempt', 'quiz', $attempt->attempt) . ': ';
 543              if ($attempt->state != quiz_attempt::FINISHED) {
 544                  echo quiz_attempt_state_name($attempt->state);
 545              } else {
 546                  if (!isset($gitem)) {
 547                      if (!empty($grades->items[0]->grades)) {
 548                          $gitem = grade_item::fetch(array('id' => $grades->items[0]->id));
 549                      } else {
 550                          $gitem = new stdClass();
 551                          $gitem->hidden = true;
 552                      }
 553                  }
 554                  if (!$gitem->hidden || has_capability('moodle/grade:viewhidden', context_course::instance($course->id))) {
 555                      echo quiz_format_grade($quiz, $attempt->sumgrades) . '/' . quiz_format_grade($quiz, $quiz->sumgrades);
 556                  } else {
 557                      echo get_string('hidden', 'grades');
 558                  }
 559                  echo ' - '.userdate($attempt->timefinish).'<br />';
 560              }
 561          }
 562      } else {
 563          print_string('noattempts', 'quiz');
 564      }
 565  
 566      return true;
 567  }
 568  
 569  
 570  /**
 571   * @param int|array $quizids A quiz ID, or an array of quiz IDs.
 572   * @param int $userid the userid.
 573   * @param string $status 'all', 'finished' or 'unfinished' to control
 574   * @param bool $includepreviews
 575   * @return array of all the user's attempts at this quiz. Returns an empty
 576   *      array if there are none.
 577   */
 578  function quiz_get_user_attempts($quizids, $userid, $status = 'finished', $includepreviews = false) {
 579      global $DB, $CFG;
 580      // TODO MDL-33071 it is very annoying to have to included all of locallib.php
 581      // just to get the quiz_attempt::FINISHED constants, but I will try to sort
 582      // that out properly for Moodle 2.4. For now, I will just do a quick fix for
 583      // MDL-33048.
 584      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 585  
 586      $params = array();
 587      switch ($status) {
 588          case 'all':
 589              $statuscondition = '';
 590              break;
 591  
 592          case 'finished':
 593              $statuscondition = ' AND state IN (:state1, :state2)';
 594              $params['state1'] = quiz_attempt::FINISHED;
 595              $params['state2'] = quiz_attempt::ABANDONED;
 596              break;
 597  
 598          case 'unfinished':
 599              $statuscondition = ' AND state IN (:state1, :state2)';
 600              $params['state1'] = quiz_attempt::IN_PROGRESS;
 601              $params['state2'] = quiz_attempt::OVERDUE;
 602              break;
 603      }
 604  
 605      $quizids = (array) $quizids;
 606      list($insql, $inparams) = $DB->get_in_or_equal($quizids, SQL_PARAMS_NAMED);
 607      $params += $inparams;
 608      $params['userid'] = $userid;
 609  
 610      $previewclause = '';
 611      if (!$includepreviews) {
 612          $previewclause = ' AND preview = 0';
 613      }
 614  
 615      return $DB->get_records_select('quiz_attempts',
 616              "quiz $insql AND userid = :userid" . $previewclause . $statuscondition,
 617              $params, 'quiz, attempt ASC');
 618  }
 619  
 620  /**
 621   * Return grade for given user or all users.
 622   *
 623   * @param int $quizid id of quiz
 624   * @param int $userid optional user id, 0 means all users
 625   * @return array array of grades, false if none. These are raw grades. They should
 626   * be processed with quiz_format_grade for display.
 627   */
 628  function quiz_get_user_grades($quiz, $userid = 0) {
 629      global $CFG, $DB;
 630  
 631      $params = array($quiz->id);
 632      $usertest = '';
 633      if ($userid) {
 634          $params[] = $userid;
 635          $usertest = 'AND u.id = ?';
 636      }
 637      return $DB->get_records_sql("
 638              SELECT
 639                  u.id,
 640                  u.id AS userid,
 641                  qg.grade AS rawgrade,
 642                  qg.timemodified AS dategraded,
 643                  MAX(qa.timefinish) AS datesubmitted
 644  
 645              FROM {user} u
 646              JOIN {quiz_grades} qg ON u.id = qg.userid
 647              JOIN {quiz_attempts} qa ON qa.quiz = qg.quiz AND qa.userid = u.id
 648  
 649              WHERE qg.quiz = ?
 650              $usertest
 651              GROUP BY u.id, qg.grade, qg.timemodified", $params);
 652  }
 653  
 654  /**
 655   * Round a grade to to the correct number of decimal places, and format it for display.
 656   *
 657   * @param object $quiz The quiz table row, only $quiz->decimalpoints is used.
 658   * @param float $grade The grade to round.
 659   * @return float
 660   */
 661  function quiz_format_grade($quiz, $grade) {
 662      if (is_null($grade)) {
 663          return get_string('notyetgraded', 'quiz');
 664      }
 665      return format_float($grade, $quiz->decimalpoints);
 666  }
 667  
 668  /**
 669   * Determine the correct number of decimal places required to format a grade.
 670   *
 671   * @param object $quiz The quiz table row, only $quiz->decimalpoints is used.
 672   * @return integer
 673   */
 674  function quiz_get_grade_format($quiz) {
 675      if (empty($quiz->questiondecimalpoints)) {
 676          $quiz->questiondecimalpoints = -1;
 677      }
 678  
 679      if ($quiz->questiondecimalpoints == -1) {
 680          return $quiz->decimalpoints;
 681      }
 682  
 683      return $quiz->questiondecimalpoints;
 684  }
 685  
 686  /**
 687   * Round a grade to the correct number of decimal places, and format it for display.
 688   *
 689   * @param object $quiz The quiz table row, only $quiz->decimalpoints is used.
 690   * @param float $grade The grade to round.
 691   * @return float
 692   */
 693  function quiz_format_question_grade($quiz, $grade) {
 694      return format_float($grade, quiz_get_grade_format($quiz));
 695  }
 696  
 697  /**
 698   * Update grades in central gradebook
 699   *
 700   * @category grade
 701   * @param object $quiz the quiz settings.
 702   * @param int $userid specific user only, 0 means all users.
 703   * @param bool $nullifnone If a single user is specified and $nullifnone is true a grade item with a null rawgrade will be inserted
 704   */
 705  function quiz_update_grades($quiz, $userid = 0, $nullifnone = true) {
 706      global $CFG, $DB;
 707      require_once($CFG->libdir . '/gradelib.php');
 708  
 709      if ($quiz->grade == 0) {
 710          quiz_grade_item_update($quiz);
 711  
 712      } else if ($grades = quiz_get_user_grades($quiz, $userid)) {
 713          quiz_grade_item_update($quiz, $grades);
 714  
 715      } else if ($userid && $nullifnone) {
 716          $grade = new stdClass();
 717          $grade->userid = $userid;
 718          $grade->rawgrade = null;
 719          quiz_grade_item_update($quiz, $grade);
 720  
 721      } else {
 722          quiz_grade_item_update($quiz);
 723      }
 724  }
 725  
 726  /**
 727   * Create or update the grade item for given quiz
 728   *
 729   * @category grade
 730   * @param object $quiz object with extra cmidnumber
 731   * @param mixed $grades optional array/object of grade(s); 'reset' means reset grades in gradebook
 732   * @return int 0 if ok, error code otherwise
 733   */
 734  function quiz_grade_item_update($quiz, $grades = null) {
 735      global $CFG, $OUTPUT;
 736      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 737      require_once($CFG->libdir . '/gradelib.php');
 738  
 739      if (property_exists($quiz, 'cmidnumber')) { // May not be always present.
 740          $params = array('itemname' => $quiz->name, 'idnumber' => $quiz->cmidnumber);
 741      } else {
 742          $params = array('itemname' => $quiz->name);
 743      }
 744  
 745      if ($quiz->grade > 0) {
 746          $params['gradetype'] = GRADE_TYPE_VALUE;
 747          $params['grademax']  = $quiz->grade;
 748          $params['grademin']  = 0;
 749  
 750      } else {
 751          $params['gradetype'] = GRADE_TYPE_NONE;
 752      }
 753  
 754      // What this is trying to do:
 755      // 1. If the quiz is set to not show grades while the quiz is still open,
 756      //    and is set to show grades after the quiz is closed, then create the
 757      //    grade_item with a show-after date that is the quiz close date.
 758      // 2. If the quiz is set to not show grades at either of those times,
 759      //    create the grade_item as hidden.
 760      // 3. If the quiz is set to show grades, create the grade_item visible.
 761      $openreviewoptions = mod_quiz_display_options::make_from_quiz($quiz,
 762              mod_quiz_display_options::LATER_WHILE_OPEN);
 763      $closedreviewoptions = mod_quiz_display_options::make_from_quiz($quiz,
 764              mod_quiz_display_options::AFTER_CLOSE);
 765      if ($openreviewoptions->marks < question_display_options::MARK_AND_MAX &&
 766              $closedreviewoptions->marks < question_display_options::MARK_AND_MAX) {
 767          $params['hidden'] = 1;
 768  
 769      } else if ($openreviewoptions->marks < question_display_options::MARK_AND_MAX &&
 770              $closedreviewoptions->marks >= question_display_options::MARK_AND_MAX) {
 771          if ($quiz->timeclose) {
 772              $params['hidden'] = $quiz->timeclose;
 773          } else {
 774              $params['hidden'] = 1;
 775          }
 776  
 777      } else {
 778          // Either
 779          // a) both open and closed enabled
 780          // b) open enabled, closed disabled - we can not "hide after",
 781          //    grades are kept visible even after closing.
 782          $params['hidden'] = 0;
 783      }
 784  
 785      if (!$params['hidden']) {
 786          // If the grade item is not hidden by the quiz logic, then we need to
 787          // hide it if the quiz is hidden from students.
 788          if (property_exists($quiz, 'visible')) {
 789              // Saving the quiz form, and cm not yet updated in the database.
 790              $params['hidden'] = !$quiz->visible;
 791          } else {
 792              $cm = get_coursemodule_from_instance('quiz', $quiz->id);
 793              $params['hidden'] = !$cm->visible;
 794          }
 795      }
 796  
 797      if ($grades  === 'reset') {
 798          $params['reset'] = true;
 799          $grades = null;
 800      }
 801  
 802      $gradebook_grades = grade_get_grades($quiz->course, 'mod', 'quiz', $quiz->id);
 803      if (!empty($gradebook_grades->items)) {
 804          $grade_item = $gradebook_grades->items[0];
 805          if ($grade_item->locked) {
 806              // NOTE: this is an extremely nasty hack! It is not a bug if this confirmation fails badly. --skodak.
 807              $confirm_regrade = optional_param('confirm_regrade', 0, PARAM_INT);
 808              if (!$confirm_regrade) {
 809                  if (!AJAX_SCRIPT) {
 810                      $message = get_string('gradeitemislocked', 'grades');
 811                      $back_link = $CFG->wwwroot . '/mod/quiz/report.php?q=' . $quiz->id .
 812                              '&amp;mode=overview';
 813                      $regrade_link = qualified_me() . '&amp;confirm_regrade=1';
 814                      echo $OUTPUT->box_start('generalbox', 'notice');
 815                      echo '<p>'. $message .'</p>';
 816                      echo $OUTPUT->container_start('buttons');
 817                      echo $OUTPUT->single_button($regrade_link, get_string('regradeanyway', 'grades'));
 818                      echo $OUTPUT->single_button($back_link,  get_string('cancel'));
 819                      echo $OUTPUT->container_end();
 820                      echo $OUTPUT->box_end();
 821                  }
 822                  return GRADE_UPDATE_ITEM_LOCKED;
 823              }
 824          }
 825      }
 826  
 827      return grade_update('mod/quiz', $quiz->course, 'mod', 'quiz', $quiz->id, 0, $grades, $params);
 828  }
 829  
 830  /**
 831   * Delete grade item for given quiz
 832   *
 833   * @category grade
 834   * @param object $quiz object
 835   * @return object quiz
 836   */
 837  function quiz_grade_item_delete($quiz) {
 838      global $CFG;
 839      require_once($CFG->libdir . '/gradelib.php');
 840  
 841      return grade_update('mod/quiz', $quiz->course, 'mod', 'quiz', $quiz->id, 0,
 842              null, array('deleted' => 1));
 843  }
 844  
 845  /**
 846   * This standard function will check all instances of this module
 847   * and make sure there are up-to-date events created for each of them.
 848   * If courseid = 0, then every quiz event in the site is checked, else
 849   * only quiz events belonging to the course specified are checked.
 850   * This function is used, in its new format, by restore_refresh_events()
 851   *
 852   * @param int $courseid
 853   * @param int|stdClass $instance Quiz module instance or ID.
 854   * @param int|stdClass $cm Course module object or ID (not used in this module).
 855   * @return bool
 856   */
 857  function quiz_refresh_events($courseid = 0, $instance = null, $cm = null) {
 858      global $DB;
 859  
 860      // If we have instance information then we can just update the one event instead of updating all events.
 861      if (isset($instance)) {
 862          if (!is_object($instance)) {
 863              $instance = $DB->get_record('quiz', array('id' => $instance), '*', MUST_EXIST);
 864          }
 865          quiz_update_events($instance);
 866          return true;
 867      }
 868  
 869      if ($courseid == 0) {
 870          if (!$quizzes = $DB->get_records('quiz')) {
 871              return true;
 872          }
 873      } else {
 874          if (!$quizzes = $DB->get_records('quiz', array('course' => $courseid))) {
 875              return true;
 876          }
 877      }
 878  
 879      foreach ($quizzes as $quiz) {
 880          quiz_update_events($quiz);
 881      }
 882  
 883      return true;
 884  }
 885  
 886  /**
 887   * Returns all quiz graded users since a given time for specified quiz
 888   */
 889  function quiz_get_recent_mod_activity(&$activities, &$index, $timestart,
 890          $courseid, $cmid, $userid = 0, $groupid = 0) {
 891      global $CFG, $USER, $DB;
 892      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
 893  
 894      $course = get_course($courseid);
 895      $modinfo = get_fast_modinfo($course);
 896  
 897      $cm = $modinfo->cms[$cmid];
 898      $quiz = $DB->get_record('quiz', array('id' => $cm->instance));
 899  
 900      if ($userid) {
 901          $userselect = "AND u.id = :userid";
 902          $params['userid'] = $userid;
 903      } else {
 904          $userselect = '';
 905      }
 906  
 907      if ($groupid) {
 908          $groupselect = 'AND gm.groupid = :groupid';
 909          $groupjoin   = 'JOIN {groups_members} gm ON  gm.userid=u.id';
 910          $params['groupid'] = $groupid;
 911      } else {
 912          $groupselect = '';
 913          $groupjoin   = '';
 914      }
 915  
 916      $params['timestart'] = $timestart;
 917      $params['quizid'] = $quiz->id;
 918  
 919      $userfieldsapi = \core_user\fields::for_userpic();
 920      $ufields = $userfieldsapi->get_sql('u', false, '', 'useridagain', false)->selects;
 921      if (!$attempts = $DB->get_records_sql("
 922                SELECT qa.*,
 923                       {$ufields}
 924                  FROM {quiz_attempts} qa
 925                       JOIN {user} u ON u.id = qa.userid
 926                       $groupjoin
 927                 WHERE qa.timefinish > :timestart
 928                   AND qa.quiz = :quizid
 929                   AND qa.preview = 0
 930                       $userselect
 931                       $groupselect
 932              ORDER BY qa.timefinish ASC", $params)) {
 933          return;
 934      }
 935  
 936      $context         = context_module::instance($cm->id);
 937      $accessallgroups = has_capability('moodle/site:accessallgroups', $context);
 938      $viewfullnames   = has_capability('moodle/site:viewfullnames', $context);
 939      $grader          = has_capability('mod/quiz:viewreports', $context);
 940      $groupmode       = groups_get_activity_groupmode($cm, $course);
 941  
 942      $usersgroups = null;
 943      $aname = format_string($cm->name, true);
 944      foreach ($attempts as $attempt) {
 945          if ($attempt->userid != $USER->id) {
 946              if (!$grader) {
 947                  // Grade permission required.
 948                  continue;
 949              }
 950  
 951              if ($groupmode == SEPARATEGROUPS and !$accessallgroups) {
 952                  $usersgroups = groups_get_all_groups($course->id,
 953                          $attempt->userid, $cm->groupingid);
 954                  $usersgroups = array_keys($usersgroups);
 955                  if (!array_intersect($usersgroups, $modinfo->get_groups($cm->groupingid))) {
 956                      continue;
 957                  }
 958              }
 959          }
 960  
 961          $options = quiz_get_review_options($quiz, $attempt, $context);
 962  
 963          $tmpactivity = new stdClass();
 964  
 965          $tmpactivity->type       = 'quiz';
 966          $tmpactivity->cmid       = $cm->id;
 967          $tmpactivity->name       = $aname;
 968          $tmpactivity->sectionnum = $cm->sectionnum;
 969          $tmpactivity->timestamp  = $attempt->timefinish;
 970  
 971          $tmpactivity->content = new stdClass();
 972          $tmpactivity->content->attemptid = $attempt->id;
 973          $tmpactivity->content->attempt   = $attempt->attempt;
 974          if (quiz_has_grades($quiz) && $options->marks >= question_display_options::MARK_AND_MAX) {
 975              $tmpactivity->content->sumgrades = quiz_format_grade($quiz, $attempt->sumgrades);
 976              $tmpactivity->content->maxgrade  = quiz_format_grade($quiz, $quiz->sumgrades);
 977          } else {
 978              $tmpactivity->content->sumgrades = null;
 979              $tmpactivity->content->maxgrade  = null;
 980          }
 981  
 982          $tmpactivity->user = user_picture::unalias($attempt, null, 'useridagain');
 983          $tmpactivity->user->fullname  = fullname($tmpactivity->user, $viewfullnames);
 984  
 985          $activities[$index++] = $tmpactivity;
 986      }
 987  }
 988  
 989  function quiz_print_recent_mod_activity($activity, $courseid, $detail, $modnames) {
 990      global $CFG, $OUTPUT;
 991  
 992      echo '<table border="0" cellpadding="3" cellspacing="0" class="forum-recent">';
 993  
 994      echo '<tr><td class="userpicture" valign="top">';
 995      echo $OUTPUT->user_picture($activity->user, array('courseid' => $courseid));
 996      echo '</td><td>';
 997  
 998      if ($detail) {
 999          $modname = $modnames[$activity->type];
1000          echo '<div class="title">';
1001          echo $OUTPUT->image_icon('monologo', $modname, $activity->type);
1002          echo '<a href="' . $CFG->wwwroot . '/mod/quiz/view.php?id=' .
1003                  $activity->cmid . '">' . $activity->name . '</a>';
1004          echo '</div>';
1005      }
1006  
1007      echo '<div class="grade">';
1008      echo  get_string('attempt', 'quiz', $activity->content->attempt);
1009      if (isset($activity->content->maxgrade)) {
1010          $grades = $activity->content->sumgrades . ' / ' . $activity->content->maxgrade;
1011          echo ': (<a href="' . $CFG->wwwroot . '/mod/quiz/review.php?attempt=' .
1012                  $activity->content->attemptid . '">' . $grades . '</a>)';
1013      }
1014      echo '</div>';
1015  
1016      echo '<div class="user">';
1017      echo '<a href="' . $CFG->wwwroot . '/user/view.php?id=' . $activity->user->id .
1018              '&amp;course=' . $courseid . '">' . $activity->user->fullname .
1019              '</a> - ' . userdate($activity->timestamp);
1020      echo '</div>';
1021  
1022      echo '</td></tr></table>';
1023  
1024      return;
1025  }
1026  
1027  /**
1028   * Pre-process the quiz options form data, making any necessary adjustments.
1029   * Called by add/update instance in this file.
1030   *
1031   * @param object $quiz The variables set on the form.
1032   */
1033  function quiz_process_options($quiz) {
1034      global $CFG;
1035      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
1036      require_once($CFG->libdir . '/questionlib.php');
1037  
1038      $quiz->timemodified = time();
1039  
1040      // Quiz name.
1041      if (!empty($quiz->name)) {
1042          $quiz->name = trim($quiz->name);
1043      }
1044  
1045      // Password field - different in form to stop browsers that remember passwords
1046      // getting confused.
1047      $quiz->password = $quiz->quizpassword;
1048      unset($quiz->quizpassword);
1049  
1050      // Quiz feedback.
1051      if (isset($quiz->feedbacktext)) {
1052          // Clean up the boundary text.
1053          for ($i = 0; $i < count($quiz->feedbacktext); $i += 1) {
1054              if (empty($quiz->feedbacktext[$i]['text'])) {
1055                  $quiz->feedbacktext[$i]['text'] = '';
1056              } else {
1057                  $quiz->feedbacktext[$i]['text'] = trim($quiz->feedbacktext[$i]['text']);
1058              }
1059          }
1060  
1061          // Check the boundary value is a number or a percentage, and in range.
1062          $i = 0;
1063          while (!empty($quiz->feedbackboundaries[$i])) {
1064              $boundary = trim($quiz->feedbackboundaries[$i]);
1065              if (!is_numeric($boundary)) {
1066                  if (strlen($boundary) > 0 && $boundary[strlen($boundary) - 1] == '%') {
1067                      $boundary = trim(substr($boundary, 0, -1));
1068                      if (is_numeric($boundary)) {
1069                          $boundary = $boundary * $quiz->grade / 100.0;
1070                      } else {
1071                          return get_string('feedbackerrorboundaryformat', 'quiz', $i + 1);
1072                      }
1073                  }
1074              }
1075              if ($boundary <= 0 || $boundary >= $quiz->grade) {
1076                  return get_string('feedbackerrorboundaryoutofrange', 'quiz', $i + 1);
1077              }
1078              if ($i > 0 && $boundary >= $quiz->feedbackboundaries[$i - 1]) {
1079                  return get_string('feedbackerrororder', 'quiz', $i + 1);
1080              }
1081              $quiz->feedbackboundaries[$i] = $boundary;
1082              $i += 1;
1083          }
1084          $numboundaries = $i;
1085  
1086          // Check there is nothing in the remaining unused fields.
1087          if (!empty($quiz->feedbackboundaries)) {
1088              for ($i = $numboundaries; $i < count($quiz->feedbackboundaries); $i += 1) {
1089                  if (!empty($quiz->feedbackboundaries[$i]) &&
1090                          trim($quiz->feedbackboundaries[$i]) != '') {
1091                      return get_string('feedbackerrorjunkinboundary', 'quiz', $i + 1);
1092                  }
1093              }
1094          }
1095          for ($i = $numboundaries + 1; $i < count($quiz->feedbacktext); $i += 1) {
1096              if (!empty($quiz->feedbacktext[$i]['text']) &&
1097                      trim($quiz->feedbacktext[$i]['text']) != '') {
1098                  return get_string('feedbackerrorjunkinfeedback', 'quiz', $i + 1);
1099              }
1100          }
1101          // Needs to be bigger than $quiz->grade because of '<' test in quiz_feedback_for_grade().
1102          $quiz->feedbackboundaries[-1] = $quiz->grade + 1;
1103          $quiz->feedbackboundaries[$numboundaries] = 0;
1104          $quiz->feedbackboundarycount = $numboundaries;
1105      } else {
1106          $quiz->feedbackboundarycount = -1;
1107      }
1108  
1109      // Combing the individual settings into the review columns.
1110      $quiz->reviewattempt = quiz_review_option_form_to_db($quiz, 'attempt');
1111      $quiz->reviewcorrectness = quiz_review_option_form_to_db($quiz, 'correctness');
1112      $quiz->reviewmarks = quiz_review_option_form_to_db($quiz, 'marks');
1113      $quiz->reviewspecificfeedback = quiz_review_option_form_to_db($quiz, 'specificfeedback');
1114      $quiz->reviewgeneralfeedback = quiz_review_option_form_to_db($quiz, 'generalfeedback');
1115      $quiz->reviewrightanswer = quiz_review_option_form_to_db($quiz, 'rightanswer');
1116      $quiz->reviewoverallfeedback = quiz_review_option_form_to_db($quiz, 'overallfeedback');
1117      $quiz->reviewattempt |= mod_quiz_display_options::DURING;
1118      $quiz->reviewoverallfeedback &= ~mod_quiz_display_options::DURING;
1119  
1120      // Ensure that disabled checkboxes in completion settings are set to 0.
1121      // But only if the completion settinsg are unlocked.
1122      if (!empty($quiz->completionunlocked)) {
1123          if (empty($quiz->completionusegrade)) {
1124              $quiz->completionpassgrade = 0;
1125          }
1126          if (empty($quiz->completionpassgrade)) {
1127              $quiz->completionattemptsexhausted = 0;
1128          }
1129          if (empty($quiz->completionminattemptsenabled)) {
1130              $quiz->completionminattempts = 0;
1131          }
1132      }
1133  }
1134  
1135  /**
1136   * Helper function for {@link quiz_process_options()}.
1137   * @param object $fromform the sumbitted form date.
1138   * @param string $field one of the review option field names.
1139   */
1140  function quiz_review_option_form_to_db($fromform, $field) {
1141      static $times = array(
1142          'during' => mod_quiz_display_options::DURING,
1143          'immediately' => mod_quiz_display_options::IMMEDIATELY_AFTER,
1144          'open' => mod_quiz_display_options::LATER_WHILE_OPEN,
1145          'closed' => mod_quiz_display_options::AFTER_CLOSE,
1146      );
1147  
1148      $review = 0;
1149      foreach ($times as $whenname => $when) {
1150          $fieldname = $field . $whenname;
1151          if (!empty($fromform->$fieldname)) {
1152              $review |= $when;
1153              unset($fromform->$fieldname);
1154          }
1155      }
1156  
1157      return $review;
1158  }
1159  
1160  /**
1161   * This function is called at the end of quiz_add_instance
1162   * and quiz_update_instance, to do the common processing.
1163   *
1164   * @param object $quiz the quiz object.
1165   */
1166  function quiz_after_add_or_update($quiz) {
1167      global $DB;
1168      $cmid = $quiz->coursemodule;
1169  
1170      // We need to use context now, so we need to make sure all needed info is already in db.
1171      $DB->set_field('course_modules', 'instance', $quiz->id, array('id'=>$cmid));
1172      $context = context_module::instance($cmid);
1173  
1174      // Save the feedback.
1175      $DB->delete_records('quiz_feedback', array('quizid' => $quiz->id));
1176  
1177      for ($i = 0; $i <= $quiz->feedbackboundarycount; $i++) {
1178          $feedback = new stdClass();
1179          $feedback->quizid = $quiz->id;
1180          $feedback->feedbacktext = $quiz->feedbacktext[$i]['text'];
1181          $feedback->feedbacktextformat = $quiz->feedbacktext[$i]['format'];
1182          $feedback->mingrade = $quiz->feedbackboundaries[$i];
1183          $feedback->maxgrade = $quiz->feedbackboundaries[$i - 1];
1184          $feedback->id = $DB->insert_record('quiz_feedback', $feedback);
1185          $feedbacktext = file_save_draft_area_files((int)$quiz->feedbacktext[$i]['itemid'],
1186                  $context->id, 'mod_quiz', 'feedback', $feedback->id,
1187                  array('subdirs' => false, 'maxfiles' => -1, 'maxbytes' => 0),
1188                  $quiz->feedbacktext[$i]['text']);
1189          $DB->set_field('quiz_feedback', 'feedbacktext', $feedbacktext,
1190                  array('id' => $feedback->id));
1191      }
1192  
1193      // Store any settings belonging to the access rules.
1194      quiz_access_manager::save_settings($quiz);
1195  
1196      // Update the events relating to this quiz.
1197      quiz_update_events($quiz);
1198      $completionexpected = (!empty($quiz->completionexpected)) ? $quiz->completionexpected : null;
1199      \core_completion\api::update_completion_date_event($quiz->coursemodule, 'quiz', $quiz->id, $completionexpected);
1200  
1201      // Update related grade item.
1202      quiz_grade_item_update($quiz);
1203  }
1204  
1205  /**
1206   * This function updates the events associated to the quiz.
1207   * If $override is non-zero, then it updates only the events
1208   * associated with the specified override.
1209   *
1210   * @uses QUIZ_MAX_EVENT_LENGTH
1211   * @param object $quiz the quiz object.
1212   * @param object optional $override limit to a specific override
1213   */
1214  function quiz_update_events($quiz, $override = null) {
1215      global $DB;
1216  
1217      // Load the old events relating to this quiz.
1218      $conds = array('modulename'=>'quiz',
1219                     'instance'=>$quiz->id);
1220      if (!empty($override)) {
1221          // Only load events for this override.
1222          if (isset($override->userid)) {
1223              $conds['userid'] = $override->userid;
1224          } else {
1225              $conds['groupid'] = $override->groupid;
1226          }
1227      }
1228      $oldevents = $DB->get_records('event', $conds, 'id ASC');
1229  
1230      // Now make a to-do list of all that needs to be updated.
1231      if (empty($override)) {
1232          // We are updating the primary settings for the quiz, so we need to add all the overrides.
1233          $overrides = $DB->get_records('quiz_overrides', array('quiz' => $quiz->id), 'id ASC');
1234          // It is necessary to add an empty stdClass to the beginning of the array as the $oldevents
1235          // list contains the original (non-override) event for the module. If this is not included
1236          // the logic below will end up updating the wrong row when we try to reconcile this $overrides
1237          // list against the $oldevents list.
1238          array_unshift($overrides, new stdClass());
1239      } else {
1240          // Just do the one override.
1241          $overrides = array($override);
1242      }
1243  
1244      // Get group override priorities.
1245      $grouppriorities = quiz_get_group_override_priorities($quiz->id);
1246  
1247      foreach ($overrides as $current) {
1248          $groupid   = isset($current->groupid)?  $current->groupid : 0;
1249          $userid    = isset($current->userid)? $current->userid : 0;
1250          $timeopen  = isset($current->timeopen)?  $current->timeopen : $quiz->timeopen;
1251          $timeclose = isset($current->timeclose)? $current->timeclose : $quiz->timeclose;
1252  
1253          // Only add open/close events for an override if they differ from the quiz default.
1254          $addopen  = empty($current->id) || !empty($current->timeopen);
1255          $addclose = empty($current->id) || !empty($current->timeclose);
1256  
1257          if (!empty($quiz->coursemodule)) {
1258              $cmid = $quiz->coursemodule;
1259          } else {
1260              $cmid = get_coursemodule_from_instance('quiz', $quiz->id, $quiz->course)->id;
1261          }
1262  
1263          $event = new stdClass();
1264          $event->type = !$timeclose ? CALENDAR_EVENT_TYPE_ACTION : CALENDAR_EVENT_TYPE_STANDARD;
1265          $event->description = format_module_intro('quiz', $quiz, $cmid, false);
1266          $event->format = FORMAT_HTML;
1267          // Events module won't show user events when the courseid is nonzero.
1268          $event->courseid    = ($userid) ? 0 : $quiz->course;
1269          $event->groupid     = $groupid;
1270          $event->userid      = $userid;
1271          $event->modulename  = 'quiz';
1272          $event->instance    = $quiz->id;
1273          $event->timestart   = $timeopen;
1274          $event->timeduration = max($timeclose - $timeopen, 0);
1275          $event->timesort    = $timeopen;
1276          $event->visible     = instance_is_visible('quiz', $quiz);
1277          $event->eventtype   = QUIZ_EVENT_TYPE_OPEN;
1278          $event->priority    = null;
1279  
1280          // Determine the event name and priority.
1281          if ($groupid) {
1282              // Group override event.
1283              $params = new stdClass();
1284              $params->quiz = $quiz->name;
1285              $params->group = groups_get_group_name($groupid);
1286              if ($params->group === false) {
1287                  // Group doesn't exist, just skip it.
1288                  continue;
1289              }
1290              $eventname = get_string('overridegroupeventname', 'quiz', $params);
1291              // Set group override priority.
1292              if ($grouppriorities !== null) {
1293                  $openpriorities = $grouppriorities['open'];
1294                  if (isset($openpriorities[$timeopen])) {
1295                      $event->priority = $openpriorities[$timeopen];
1296                  }
1297              }
1298          } else if ($userid) {
1299              // User override event.
1300              $params = new stdClass();
1301              $params->quiz = $quiz->name;
1302              $eventname = get_string('overrideusereventname', 'quiz', $params);
1303              // Set user override priority.
1304              $event->priority = CALENDAR_EVENT_USER_OVERRIDE_PRIORITY;
1305          } else {
1306              // The parent event.
1307              $eventname = $quiz->name;
1308          }
1309  
1310          if ($addopen or $addclose) {
1311              // Separate start and end events.
1312              $event->timeduration  = 0;
1313              if ($timeopen && $addopen) {
1314                  if ($oldevent = array_shift($oldevents)) {
1315                      $event->id = $oldevent->id;
1316                  } else {
1317                      unset($event->id);
1318                  }
1319                  $event->name = get_string('quizeventopens', 'quiz', $eventname);
1320                  // The method calendar_event::create will reuse a db record if the id field is set.
1321                  calendar_event::create($event, false);
1322              }
1323              if ($timeclose && $addclose) {
1324                  if ($oldevent = array_shift($oldevents)) {
1325                      $event->id = $oldevent->id;
1326                  } else {
1327                      unset($event->id);
1328                  }
1329                  $event->type      = CALENDAR_EVENT_TYPE_ACTION;
1330                  $event->name      = get_string('quizeventcloses', 'quiz', $eventname);
1331                  $event->timestart = $timeclose;
1332                  $event->timesort  = $timeclose;
1333                  $event->eventtype = QUIZ_EVENT_TYPE_CLOSE;
1334                  if ($groupid && $grouppriorities !== null) {
1335                      $closepriorities = $grouppriorities['close'];
1336                      if (isset($closepriorities[$timeclose])) {
1337                          $event->priority = $closepriorities[$timeclose];
1338                      }
1339                  }
1340                  calendar_event::create($event, false);
1341              }
1342          }
1343      }
1344  
1345      // Delete any leftover events.
1346      foreach ($oldevents as $badevent) {
1347          $badevent = calendar_event::load($badevent);
1348          $badevent->delete();
1349      }
1350  }
1351  
1352  /**
1353   * Calculates the priorities of timeopen and timeclose values for group overrides for a quiz.
1354   *
1355   * @param int $quizid The quiz ID.
1356   * @return array|null Array of group override priorities for open and close times. Null if there are no group overrides.
1357   */
1358  function quiz_get_group_override_priorities($quizid) {
1359      global $DB;
1360  
1361      // Fetch group overrides.
1362      $where = 'quiz = :quiz AND groupid IS NOT NULL';
1363      $params = ['quiz' => $quizid];
1364      $overrides = $DB->get_records_select('quiz_overrides', $where, $params, '', 'id, timeopen, timeclose');
1365      if (!$overrides) {
1366          return null;
1367      }
1368  
1369      $grouptimeopen = [];
1370      $grouptimeclose = [];
1371      foreach ($overrides as $override) {
1372          if ($override->timeopen !== null && !in_array($override->timeopen, $grouptimeopen)) {
1373              $grouptimeopen[] = $override->timeopen;
1374          }
1375          if ($override->timeclose !== null && !in_array($override->timeclose, $grouptimeclose)) {
1376              $grouptimeclose[] = $override->timeclose;
1377          }
1378      }
1379  
1380      // Sort open times in ascending manner. The earlier open time gets higher priority.
1381      sort($grouptimeopen);
1382      // Set priorities.
1383      $opengrouppriorities = [];
1384      $openpriority = 1;
1385      foreach ($grouptimeopen as $timeopen) {
1386          $opengrouppriorities[$timeopen] = $openpriority++;
1387      }
1388  
1389      // Sort close times in descending manner. The later close time gets higher priority.
1390      rsort($grouptimeclose);
1391      // Set priorities.
1392      $closegrouppriorities = [];
1393      $closepriority = 1;
1394      foreach ($grouptimeclose as $timeclose) {
1395          $closegrouppriorities[$timeclose] = $closepriority++;
1396      }
1397  
1398      return [
1399          'open' => $opengrouppriorities,
1400          'close' => $closegrouppriorities
1401      ];
1402  }
1403  
1404  /**
1405   * List the actions that correspond to a view of this module.
1406   * This is used by the participation report.
1407   *
1408   * Note: This is not used by new logging system. Event with
1409   *       crud = 'r' and edulevel = LEVEL_PARTICIPATING will
1410   *       be considered as view action.
1411   *
1412   * @return array
1413   */
1414  function quiz_get_view_actions() {
1415      return array('view', 'view all', 'report', 'review');
1416  }
1417  
1418  /**
1419   * List the actions that correspond to a post of this module.
1420   * This is used by the participation report.
1421   *
1422   * Note: This is not used by new logging system. Event with
1423   *       crud = ('c' || 'u' || 'd') and edulevel = LEVEL_PARTICIPATING
1424   *       will be considered as post action.
1425   *
1426   * @return array
1427   */
1428  function quiz_get_post_actions() {
1429      return array('attempt', 'close attempt', 'preview', 'editquestions',
1430              'delete attempt', 'manualgrade');
1431  }
1432  
1433  /**
1434   * Standard callback used by questions_in_use.
1435   *
1436   * @param array $questionids of question ids.
1437   * @return bool whether any of these questions are used by any instance of this module.
1438   */
1439  function quiz_questions_in_use($questionids) {
1440      return question_engine::questions_in_use($questionids,
1441              new qubaid_join('{quiz_attempts} quiza', 'quiza.uniqueid',
1442                  'quiza.preview = 0'));
1443  }
1444  
1445  /**
1446   * Implementation of the function for printing the form elements that control
1447   * whether the course reset functionality affects the quiz.
1448   *
1449   * @param $mform the course reset form that is being built.
1450   */
1451  function quiz_reset_course_form_definition($mform) {
1452      $mform->addElement('header', 'quizheader', get_string('modulenameplural', 'quiz'));
1453      $mform->addElement('advcheckbox', 'reset_quiz_attempts',
1454              get_string('removeallquizattempts', 'quiz'));
1455      $mform->addElement('advcheckbox', 'reset_quiz_user_overrides',
1456              get_string('removealluseroverrides', 'quiz'));
1457      $mform->addElement('advcheckbox', 'reset_quiz_group_overrides',
1458              get_string('removeallgroupoverrides', 'quiz'));
1459  }
1460  
1461  /**
1462   * Course reset form defaults.
1463   * @return array the defaults.
1464   */
1465  function quiz_reset_course_form_defaults($course) {
1466      return array('reset_quiz_attempts' => 1,
1467                   'reset_quiz_group_overrides' => 1,
1468                   'reset_quiz_user_overrides' => 1);
1469  }
1470  
1471  /**
1472   * Removes all grades from gradebook
1473   *
1474   * @param int $courseid
1475   * @param string optional type
1476   */
1477  function quiz_reset_gradebook($courseid, $type='') {
1478      global $CFG, $DB;
1479  
1480      $quizzes = $DB->get_records_sql("
1481              SELECT q.*, cm.idnumber as cmidnumber, q.course as courseid
1482              FROM {modules} m
1483              JOIN {course_modules} cm ON m.id = cm.module
1484              JOIN {quiz} q ON cm.instance = q.id
1485              WHERE m.name = 'quiz' AND cm.course = ?", array($courseid));
1486  
1487      foreach ($quizzes as $quiz) {
1488          quiz_grade_item_update($quiz, 'reset');
1489      }
1490  }
1491  
1492  /**
1493   * Actual implementation of the reset course functionality, delete all the
1494   * quiz attempts for course $data->courseid, if $data->reset_quiz_attempts is
1495   * set and true.
1496   *
1497   * Also, move the quiz open and close dates, if the course start date is changing.
1498   *
1499   * @param object $data the data submitted from the reset course.
1500   * @return array status array
1501   */
1502  function quiz_reset_userdata($data) {
1503      global $CFG, $DB;
1504      require_once($CFG->libdir . '/questionlib.php');
1505  
1506      $componentstr = get_string('modulenameplural', 'quiz');
1507      $status = array();
1508  
1509      // Delete attempts.
1510      if (!empty($data->reset_quiz_attempts)) {
1511          question_engine::delete_questions_usage_by_activities(new qubaid_join(
1512                  '{quiz_attempts} quiza JOIN {quiz} quiz ON quiza.quiz = quiz.id',
1513                  'quiza.uniqueid', 'quiz.course = :quizcourseid',
1514                  array('quizcourseid' => $data->courseid)));
1515  
1516          $DB->delete_records_select('quiz_attempts',
1517                  'quiz IN (SELECT id FROM {quiz} WHERE course = ?)', array($data->courseid));
1518          $status[] = array(
1519              'component' => $componentstr,
1520              'item' => get_string('attemptsdeleted', 'quiz'),
1521              'error' => false);
1522  
1523          // Remove all grades from gradebook.
1524          $DB->delete_records_select('quiz_grades',
1525                  'quiz IN (SELECT id FROM {quiz} WHERE course = ?)', array($data->courseid));
1526          if (empty($data->reset_gradebook_grades)) {
1527              quiz_reset_gradebook($data->courseid);
1528          }
1529          $status[] = array(
1530              'component' => $componentstr,
1531              'item' => get_string('gradesdeleted', 'quiz'),
1532              'error' => false);
1533      }
1534  
1535      $purgeoverrides = false;
1536  
1537      // Remove user overrides.
1538      if (!empty($data->reset_quiz_user_overrides)) {
1539          $DB->delete_records_select('quiz_overrides',
1540                  'quiz IN (SELECT id FROM {quiz} WHERE course = ?) AND userid IS NOT NULL', array($data->courseid));
1541          $status[] = array(
1542              'component' => $componentstr,
1543              'item' => get_string('useroverridesdeleted', 'quiz'),
1544              'error' => false);
1545          $purgeoverrides = true;
1546      }
1547      // Remove group overrides.
1548      if (!empty($data->reset_quiz_group_overrides)) {
1549          $DB->delete_records_select('quiz_overrides',
1550                  'quiz IN (SELECT id FROM {quiz} WHERE course = ?) AND groupid IS NOT NULL', array($data->courseid));
1551          $status[] = array(
1552              'component' => $componentstr,
1553              'item' => get_string('groupoverridesdeleted', 'quiz'),
1554              'error' => false);
1555          $purgeoverrides = true;
1556      }
1557  
1558      // Updating dates - shift may be negative too.
1559      if ($data->timeshift) {
1560          $DB->execute("UPDATE {quiz_overrides}
1561                           SET timeopen = timeopen + ?
1562                         WHERE quiz IN (SELECT id FROM {quiz} WHERE course = ?)
1563                           AND timeopen <> 0", array($data->timeshift, $data->courseid));
1564          $DB->execute("UPDATE {quiz_overrides}
1565                           SET timeclose = timeclose + ?
1566                         WHERE quiz IN (SELECT id FROM {quiz} WHERE course = ?)
1567                           AND timeclose <> 0", array($data->timeshift, $data->courseid));
1568  
1569          $purgeoverrides = true;
1570  
1571          // Any changes to the list of dates that needs to be rolled should be same during course restore and course reset.
1572          // See MDL-9367.
1573          shift_course_mod_dates('quiz', array('timeopen', 'timeclose'),
1574                  $data->timeshift, $data->courseid);
1575  
1576          $status[] = array(
1577              'component' => $componentstr,
1578              'item' => get_string('openclosedatesupdated', 'quiz'),
1579              'error' => false);
1580      }
1581  
1582      if ($purgeoverrides) {
1583          cache::make('mod_quiz', 'overrides')->purge();
1584      }
1585  
1586      return $status;
1587  }
1588  
1589  /**
1590   * @deprecated since Moodle 3.3, when the block_course_overview block was removed.
1591   */
1592  function quiz_print_overview() {
1593      throw new coding_exception('quiz_print_overview() can not be used any more and is obsolete.');
1594  }
1595  
1596  /**
1597   * Return a textual summary of the number of attempts that have been made at a particular quiz,
1598   * returns '' if no attempts have been made yet, unless $returnzero is passed as true.
1599   *
1600   * @param object $quiz the quiz object. Only $quiz->id is used at the moment.
1601   * @param object $cm the cm object. Only $cm->course, $cm->groupmode and
1602   *      $cm->groupingid fields are used at the moment.
1603   * @param bool $returnzero if false (default), when no attempts have been
1604   *      made '' is returned instead of 'Attempts: 0'.
1605   * @param int $currentgroup if there is a concept of current group where this method is being called
1606   *         (e.g. a report) pass it in here. Default 0 which means no current group.
1607   * @return string a string like "Attempts: 123", "Attemtps 123 (45 from your groups)" or
1608   *          "Attemtps 123 (45 from this group)".
1609   */
1610  function quiz_num_attempt_summary($quiz, $cm, $returnzero = false, $currentgroup = 0) {
1611      global $DB, $USER;
1612      $numattempts = $DB->count_records('quiz_attempts', array('quiz'=> $quiz->id, 'preview'=>0));
1613      if ($numattempts || $returnzero) {
1614          if (groups_get_activity_groupmode($cm)) {
1615              $a = new stdClass();
1616              $a->total = $numattempts;
1617              if ($currentgroup) {
1618                  $a->group = $DB->count_records_sql('SELECT COUNT(DISTINCT qa.id) FROM ' .
1619                          '{quiz_attempts} qa JOIN ' .
1620                          '{groups_members} gm ON qa.userid = gm.userid ' .
1621                          'WHERE quiz = ? AND preview = 0 AND groupid = ?',
1622                          array($quiz->id, $currentgroup));
1623                  return get_string('attemptsnumthisgroup', 'quiz', $a);
1624              } else if ($groups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid)) {
1625                  list($usql, $params) = $DB->get_in_or_equal(array_keys($groups));
1626                  $a->group = $DB->count_records_sql('SELECT COUNT(DISTINCT qa.id) FROM ' .
1627                          '{quiz_attempts} qa JOIN ' .
1628                          '{groups_members} gm ON qa.userid = gm.userid ' .
1629                          'WHERE quiz = ? AND preview = 0 AND ' .
1630                          "groupid $usql", array_merge(array($quiz->id), $params));
1631                  return get_string('attemptsnumyourgroups', 'quiz', $a);
1632              }
1633          }
1634          return get_string('attemptsnum', 'quiz', $numattempts);
1635      }
1636      return '';
1637  }
1638  
1639  /**
1640   * Returns the same as {@link quiz_num_attempt_summary()} but wrapped in a link
1641   * to the quiz reports.
1642   *
1643   * @param object $quiz the quiz object. Only $quiz->id is used at the moment.
1644   * @param object $cm the cm object. Only $cm->course, $cm->groupmode and
1645   *      $cm->groupingid fields are used at the moment.
1646   * @param object $context the quiz context.
1647   * @param bool $returnzero if false (default), when no attempts have been made
1648   *      '' is returned instead of 'Attempts: 0'.
1649   * @param int $currentgroup if there is a concept of current group where this method is being called
1650   *         (e.g. a report) pass it in here. Default 0 which means no current group.
1651   * @return string HTML fragment for the link.
1652   */
1653  function quiz_attempt_summary_link_to_reports($quiz, $cm, $context, $returnzero = false,
1654          $currentgroup = 0) {
1655      global $PAGE;
1656  
1657      return $PAGE->get_renderer('mod_quiz')->quiz_attempt_summary_link_to_reports(
1658              $quiz, $cm, $context, $returnzero, $currentgroup);
1659  }
1660  
1661  /**
1662   * @param string $feature FEATURE_xx constant for requested feature
1663   * @return mixed True if module supports feature, false if not, null if doesn't know or string for the module purpose.
1664   */
1665  function quiz_supports($feature) {
1666      switch($feature) {
1667          case FEATURE_GROUPS:                    return true;
1668          case FEATURE_GROUPINGS:                 return true;
1669          case FEATURE_MOD_INTRO:                 return true;
1670          case FEATURE_COMPLETION_TRACKS_VIEWS:   return true;
1671          case FEATURE_COMPLETION_HAS_RULES:      return true;
1672          case FEATURE_GRADE_HAS_GRADE:           return true;
1673          case FEATURE_GRADE_OUTCOMES:            return true;
1674          case FEATURE_BACKUP_MOODLE2:            return true;
1675          case FEATURE_SHOW_DESCRIPTION:          return true;
1676          case FEATURE_CONTROLS_GRADE_VISIBILITY: return true;
1677          case FEATURE_USES_QUESTIONS:            return true;
1678          case FEATURE_PLAGIARISM:                return true;
1679          case FEATURE_MOD_PURPOSE:               return MOD_PURPOSE_ASSESSMENT;
1680  
1681          default: return null;
1682      }
1683  }
1684  
1685  /**
1686   * @return array all other caps used in module
1687   */
1688  function quiz_get_extra_capabilities() {
1689      global $CFG;
1690      require_once($CFG->libdir . '/questionlib.php');
1691      return question_get_all_capabilities();
1692  }
1693  
1694  /**
1695   * This function extends the settings navigation block for the site.
1696   *
1697   * It is safe to rely on PAGE here as we will only ever be within the module
1698   * context when this is called
1699   *
1700   * @param settings_navigation $settings
1701   * @param navigation_node $quiznode
1702   * @return void
1703   */
1704  function quiz_extend_settings_navigation(settings_navigation $settings, navigation_node $quiznode) {
1705      global $CFG;
1706  
1707      // Require {@link questionlib.php}
1708      // Included here as we only ever want to include this file if we really need to.
1709      require_once($CFG->libdir . '/questionlib.php');
1710  
1711      // We want to add these new nodes after the Edit settings node, and before the
1712      // Locally assigned roles node. Of course, both of those are controlled by capabilities.
1713      $keys = $quiznode->get_children_key_list();
1714      $beforekey = null;
1715      $i = array_search('modedit', $keys);
1716      if ($i === false and array_key_exists(0, $keys)) {
1717          $beforekey = $keys[0];
1718      } else if (array_key_exists($i + 1, $keys)) {
1719          $beforekey = $keys[$i + 1];
1720      }
1721  
1722      if (has_any_capability(['mod/quiz:manageoverrides', 'mod/quiz:viewoverrides'], $settings->get_page()->cm->context)) {
1723          $url = new moodle_url('/mod/quiz/overrides.php', ['cmid' => $settings->get_page()->cm->id, 'mode' => 'user']);
1724          $node = navigation_node::create(get_string('overrides', 'quiz'),
1725                      $url, navigation_node::TYPE_SETTING, null, 'mod_quiz_useroverrides');
1726          $settingsoverride = $quiznode->add_node($node, $beforekey);
1727      }
1728  
1729      if (has_capability('mod/quiz:manage', $settings->get_page()->cm->context)) {
1730          $node = navigation_node::create(get_string('questions', 'quiz'),
1731              new moodle_url('/mod/quiz/edit.php', array('cmid' => $settings->get_page()->cm->id)),
1732              navigation_node::TYPE_SETTING, null, 'mod_quiz_edit', new pix_icon('t/edit', ''));
1733          $quiznode->add_node($node, $beforekey);
1734      }
1735  
1736      if (has_capability('mod/quiz:preview', $settings->get_page()->cm->context)) {
1737          $url = new moodle_url('/mod/quiz/startattempt.php',
1738                  array('cmid' => $settings->get_page()->cm->id, 'sesskey' => sesskey()));
1739          $node = navigation_node::create(get_string('preview', 'quiz'), $url,
1740                  navigation_node::TYPE_SETTING, null, 'mod_quiz_preview',
1741                  new pix_icon('i/preview', ''));
1742          $previewnode = $quiznode->add_node($node, $beforekey);
1743          $previewnode->set_show_in_secondary_navigation(false);
1744      }
1745  
1746      question_extend_settings_navigation($quiznode, $settings->get_page()->cm->context)->trim_if_empty();
1747  
1748      if (has_any_capability(array('mod/quiz:viewreports', 'mod/quiz:grade'), $settings->get_page()->cm->context)) {
1749          require_once($CFG->dirroot . '/mod/quiz/report/reportlib.php');
1750          $reportlist = quiz_report_list($settings->get_page()->cm->context);
1751  
1752          $url = new moodle_url('/mod/quiz/report.php',
1753                  array('id' => $settings->get_page()->cm->id, 'mode' => reset($reportlist)));
1754          $reportnode = $quiznode->add_node(navigation_node::create(get_string('results', 'quiz'), $url,
1755                  navigation_node::TYPE_SETTING,
1756                  null, 'quiz_report', new pix_icon('i/report', '')));
1757  
1758          foreach ($reportlist as $report) {
1759              $url = new moodle_url('/mod/quiz/report.php', ['id' => $settings->get_page()->cm->id, 'mode' => $report]);
1760              $reportnode->add_node(navigation_node::create(get_string($report, 'quiz_'.$report), $url,
1761                      navigation_node::TYPE_SETTING,
1762                      null, 'quiz_report_' . $report, new pix_icon('i/item', '')));
1763          }
1764      }
1765  }
1766  
1767  /**
1768   * Serves the quiz files.
1769   *
1770   * @package  mod_quiz
1771   * @category files
1772   * @param stdClass $course course object
1773   * @param stdClass $cm course module object
1774   * @param stdClass $context context object
1775   * @param string $filearea file area
1776   * @param array $args extra arguments
1777   * @param bool $forcedownload whether or not force download
1778   * @param array $options additional options affecting the file serving
1779   * @return bool false if file not found, does not return if found - justsend the file
1780   */
1781  function quiz_pluginfile($course, $cm, $context, $filearea, $args, $forcedownload, array $options=array()) {
1782      global $CFG, $DB;
1783  
1784      if ($context->contextlevel != CONTEXT_MODULE) {
1785          return false;
1786      }
1787  
1788      require_login($course, false, $cm);
1789  
1790      if (!$quiz = $DB->get_record('quiz', array('id'=>$cm->instance))) {
1791          return false;
1792      }
1793  
1794      // The 'intro' area is served by pluginfile.php.
1795      $fileareas = array('feedback');
1796      if (!in_array($filearea, $fileareas)) {
1797          return false;
1798      }
1799  
1800      $feedbackid = (int)array_shift($args);
1801      if (!$feedback = $DB->get_record('quiz_feedback', array('id'=>$feedbackid))) {
1802          return false;
1803      }
1804  
1805      $fs = get_file_storage();
1806      $relativepath = implode('/', $args);
1807      $fullpath = "/$context->id/mod_quiz/$filearea/$feedbackid/$relativepath";
1808      if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
1809          return false;
1810      }
1811      send_stored_file($file, 0, 0, true, $options);
1812  }
1813  
1814  /**
1815   * Called via pluginfile.php -> question_pluginfile to serve files belonging to
1816   * a question in a question_attempt when that attempt is a quiz attempt.
1817   *
1818   * @package  mod_quiz
1819   * @category files
1820   * @param stdClass $course course settings object
1821   * @param stdClass $context context object
1822   * @param string $component the name of the component we are serving files for.
1823   * @param string $filearea the name of the file area.
1824   * @param int $qubaid the attempt usage id.
1825   * @param int $slot the id of a question in this quiz attempt.
1826   * @param array $args the remaining bits of the file path.
1827   * @param bool $forcedownload whether the user must be forced to download the file.
1828   * @param array $options additional options affecting the file serving
1829   * @return bool false if file not found, does not return if found - justsend the file
1830   */
1831  function quiz_question_pluginfile($course, $context, $component,
1832          $filearea, $qubaid, $slot, $args, $forcedownload, array $options=array()) {
1833      global $CFG;
1834      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
1835  
1836      $attemptobj = quiz_attempt::create_from_usage_id($qubaid);
1837      require_login($attemptobj->get_course(), false, $attemptobj->get_cm());
1838  
1839      if ($attemptobj->is_own_attempt() && !$attemptobj->is_finished()) {
1840          // In the middle of an attempt.
1841          if (!$attemptobj->is_preview_user()) {
1842              $attemptobj->require_capability('mod/quiz:attempt');
1843          }
1844          $isreviewing = false;
1845  
1846      } else {
1847          // Reviewing an attempt.
1848          $attemptobj->check_review_capability();
1849          $isreviewing = true;
1850      }
1851  
1852      if (!$attemptobj->check_file_access($slot, $isreviewing, $context->id,
1853              $component, $filearea, $args, $forcedownload)) {
1854          send_file_not_found();
1855      }
1856  
1857      $fs = get_file_storage();
1858      $relativepath = implode('/', $args);
1859      $fullpath = "/$context->id/$component/$filearea/$relativepath";
1860      if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
1861          send_file_not_found();
1862      }
1863  
1864      send_stored_file($file, 0, 0, $forcedownload, $options);
1865  }
1866  
1867  /**
1868   * Return a list of page types
1869   * @param string $pagetype current page type
1870   * @param stdClass $parentcontext Block's parent context
1871   * @param stdClass $currentcontext Current context of block
1872   */
1873  function quiz_page_type_list($pagetype, $parentcontext, $currentcontext) {
1874      $module_pagetype = array(
1875          'mod-quiz-*'       => get_string('page-mod-quiz-x', 'quiz'),
1876          'mod-quiz-view'    => get_string('page-mod-quiz-view', 'quiz'),
1877          'mod-quiz-attempt' => get_string('page-mod-quiz-attempt', 'quiz'),
1878          'mod-quiz-summary' => get_string('page-mod-quiz-summary', 'quiz'),
1879          'mod-quiz-review'  => get_string('page-mod-quiz-review', 'quiz'),
1880          'mod-quiz-edit'    => get_string('page-mod-quiz-edit', 'quiz'),
1881          'mod-quiz-report'  => get_string('page-mod-quiz-report', 'quiz'),
1882      );
1883      return $module_pagetype;
1884  }
1885  
1886  /**
1887   * @return the options for quiz navigation.
1888   */
1889  function quiz_get_navigation_options() {
1890      return array(
1891          QUIZ_NAVMETHOD_FREE => get_string('navmethod_free', 'quiz'),
1892          QUIZ_NAVMETHOD_SEQ  => get_string('navmethod_seq', 'quiz')
1893      );
1894  }
1895  
1896  /**
1897   * Check if the module has any update that affects the current user since a given time.
1898   *
1899   * @param  cm_info $cm course module data
1900   * @param  int $from the time to check updates from
1901   * @param  array $filter  if we need to check only specific updates
1902   * @return stdClass an object with the different type of areas indicating if they were updated or not
1903   * @since Moodle 3.2
1904   */
1905  function quiz_check_updates_since(cm_info $cm, $from, $filter = array()) {
1906      global $DB, $USER, $CFG;
1907      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
1908  
1909      $updates = course_check_module_updates_since($cm, $from, array(), $filter);
1910  
1911      // Check if questions were updated.
1912      $updates->questions = (object) array('updated' => false);
1913      $quizobj = quiz::create($cm->instance, $USER->id);
1914      $quizobj->preload_questions();
1915      $quizobj->load_questions();
1916      $questionids = array_keys($quizobj->get_questions());
1917      if (!empty($questionids)) {
1918          list($questionsql, $params) = $DB->get_in_or_equal($questionids, SQL_PARAMS_NAMED);
1919          $select = 'id ' . $questionsql . ' AND (timemodified > :time1 OR timecreated > :time2)';
1920          $params['time1'] = $from;
1921          $params['time2'] = $from;
1922          $questions = $DB->get_records_select('question', $select, $params, '', 'id');
1923          if (!empty($questions)) {
1924              $updates->questions->updated = true;
1925              $updates->questions->itemids = array_keys($questions);
1926          }
1927      }
1928  
1929      // Check for new attempts or grades.
1930      $updates->attempts = (object) array('updated' => false);
1931      $updates->grades = (object) array('updated' => false);
1932      $select = 'quiz = ? AND userid = ? AND timemodified > ?';
1933      $params = array($cm->instance, $USER->id, $from);
1934  
1935      $attempts = $DB->get_records_select('quiz_attempts', $select, $params, '', 'id');
1936      if (!empty($attempts)) {
1937          $updates->attempts->updated = true;
1938          $updates->attempts->itemids = array_keys($attempts);
1939      }
1940      $grades = $DB->get_records_select('quiz_grades', $select, $params, '', 'id');
1941      if (!empty($grades)) {
1942          $updates->grades->updated = true;
1943          $updates->grades->itemids = array_keys($grades);
1944      }
1945  
1946      // Now, teachers should see other students updates.
1947      if (has_capability('mod/quiz:viewreports', $cm->context)) {
1948          $select = 'quiz = ? AND timemodified > ?';
1949          $params = array($cm->instance, $from);
1950  
1951          if (groups_get_activity_groupmode($cm) == SEPARATEGROUPS) {
1952              $groupusers = array_keys(groups_get_activity_shared_group_members($cm));
1953              if (empty($groupusers)) {
1954                  return $updates;
1955              }
1956              list($insql, $inparams) = $DB->get_in_or_equal($groupusers);
1957              $select .= ' AND userid ' . $insql;
1958              $params = array_merge($params, $inparams);
1959          }
1960  
1961          $updates->userattempts = (object) array('updated' => false);
1962          $attempts = $DB->get_records_select('quiz_attempts', $select, $params, '', 'id');
1963          if (!empty($attempts)) {
1964              $updates->userattempts->updated = true;
1965              $updates->userattempts->itemids = array_keys($attempts);
1966          }
1967  
1968          $updates->usergrades = (object) array('updated' => false);
1969          $grades = $DB->get_records_select('quiz_grades', $select, $params, '', 'id');
1970          if (!empty($grades)) {
1971              $updates->usergrades->updated = true;
1972              $updates->usergrades->itemids = array_keys($grades);
1973          }
1974      }
1975      return $updates;
1976  }
1977  
1978  /**
1979   * Get icon mapping for font-awesome.
1980   */
1981  function mod_quiz_get_fontawesome_icon_map() {
1982      return [
1983          'mod_quiz:navflagged' => 'fa-flag',
1984      ];
1985  }
1986  
1987  /**
1988   * This function receives a calendar event and returns the action associated with it, or null if there is none.
1989   *
1990   * This is used by block_myoverview in order to display the event appropriately. If null is returned then the event
1991   * is not displayed on the block.
1992   *
1993   * @param calendar_event $event
1994   * @param \core_calendar\action_factory $factory
1995   * @param int $userid User id to use for all capability checks, etc. Set to 0 for current user (default).
1996   * @return \core_calendar\local\event\entities\action_interface|null
1997   */
1998  function mod_quiz_core_calendar_provide_event_action(calendar_event $event,
1999                                                       \core_calendar\action_factory $factory,
2000                                                       int $userid = 0) {
2001      global $CFG, $USER;
2002  
2003      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
2004  
2005      if (empty($userid)) {
2006          $userid = $USER->id;
2007      }
2008  
2009      $cm = get_fast_modinfo($event->courseid, $userid)->instances['quiz'][$event->instance];
2010      $quizobj = quiz::create($cm->instance, $userid);
2011      $quiz = $quizobj->get_quiz();
2012  
2013      // Check they have capabilities allowing them to view the quiz.
2014      if (!has_any_capability(['mod/quiz:reviewmyattempts', 'mod/quiz:attempt'], $quizobj->get_context(), $userid)) {
2015          return null;
2016      }
2017  
2018      $completion = new \completion_info($cm->get_course());
2019  
2020      $completiondata = $completion->get_data($cm, false, $userid);
2021  
2022      if ($completiondata->completionstate != COMPLETION_INCOMPLETE) {
2023          return null;
2024      }
2025  
2026      quiz_update_effective_access($quiz, $userid);
2027  
2028      // Check if quiz is closed, if so don't display it.
2029      if (!empty($quiz->timeclose) && $quiz->timeclose <= time()) {
2030          return null;
2031      }
2032  
2033      if (!$quizobj->is_participant($userid)) {
2034          // If the user is not a participant then they have
2035          // no action to take. This will filter out the events for teachers.
2036          return null;
2037      }
2038  
2039      $attempts = quiz_get_user_attempts($quizobj->get_quizid(), $userid);
2040      if (!empty($attempts)) {
2041          // The student's last attempt is finished.
2042          return null;
2043      }
2044  
2045      $name = get_string('attemptquiznow', 'quiz');
2046      $url = new \moodle_url('/mod/quiz/view.php', [
2047          'id' => $cm->id
2048      ]);
2049      $itemcount = 1;
2050      $actionable = true;
2051  
2052      // Check if the quiz is not currently actionable.
2053      if (!empty($quiz->timeopen) && $quiz->timeopen > time()) {
2054          $actionable = false;
2055      }
2056  
2057      return $factory->create_instance(
2058          $name,
2059          $url,
2060          $itemcount,
2061          $actionable
2062      );
2063  }
2064  
2065  /**
2066   * Add a get_coursemodule_info function in case any quiz type wants to add 'extra' information
2067   * for the course (see resource).
2068   *
2069   * Given a course_module object, this function returns any "extra" information that may be needed
2070   * when printing this activity in a course listing.  See get_array_of_activities() in course/lib.php.
2071   *
2072   * @param stdClass $coursemodule The coursemodule object (record).
2073   * @return cached_cm_info An object on information that the courses
2074   *                        will know about (most noticeably, an icon).
2075   */
2076  function quiz_get_coursemodule_info($coursemodule) {
2077      global $DB;
2078  
2079      $dbparams = ['id' => $coursemodule->instance];
2080      $fields = 'id, name, intro, introformat, completionattemptsexhausted, completionminattempts,
2081          timeopen, timeclose';
2082      if (!$quiz = $DB->get_record('quiz', $dbparams, $fields)) {
2083          return false;
2084      }
2085  
2086      $result = new cached_cm_info();
2087      $result->name = $quiz->name;
2088  
2089      if ($coursemodule->showdescription) {
2090          // Convert intro to html. Do not filter cached version, filters run at display time.
2091          $result->content = format_module_intro('quiz', $quiz, $coursemodule->id, false);
2092      }
2093  
2094      // Populate the custom completion rules as key => value pairs, but only if the completion mode is 'automatic'.
2095      if ($coursemodule->completion == COMPLETION_TRACKING_AUTOMATIC) {
2096          if ($quiz->completionattemptsexhausted) {
2097              $result->customdata['customcompletionrules']['completionpassorattemptsexhausted'] = [
2098                  'completionpassgrade' => $coursemodule->completionpassgrade,
2099                  'completionattemptsexhausted' => $quiz->completionattemptsexhausted,
2100              ];
2101          } else {
2102              $result->customdata['customcompletionrules']['completionpassorattemptsexhausted'] = [];
2103          }
2104  
2105          $result->customdata['customcompletionrules']['completionminattempts'] = $quiz->completionminattempts;
2106      }
2107  
2108      // Populate some other values that can be used in calendar or on dashboard.
2109      if ($quiz->timeopen) {
2110          $result->customdata['timeopen'] = $quiz->timeopen;
2111      }
2112      if ($quiz->timeclose) {
2113          $result->customdata['timeclose'] = $quiz->timeclose;
2114      }
2115  
2116      return $result;
2117  }
2118  
2119  /**
2120   * Sets dynamic information about a course module
2121   *
2122   * This function is called from cm_info when displaying the module
2123   *
2124   * @param cm_info $cm
2125   */
2126  function mod_quiz_cm_info_dynamic(cm_info $cm) {
2127      global $USER;
2128  
2129      $cache = cache::make('mod_quiz', 'overrides');
2130      $override = $cache->get("{$cm->instance}_u_{$USER->id}");
2131  
2132      if (!$override) {
2133          $override = (object) [
2134              'timeopen' => null,
2135              'timeclose' => null,
2136          ];
2137      }
2138  
2139      // No need to look for group overrides if there are user overrides for both timeopen and timeclose.
2140      if (is_null($override->timeopen) || is_null($override->timeclose)) {
2141          $opens = [];
2142          $closes = [];
2143          $groupings = groups_get_user_groups($cm->course, $USER->id);
2144          foreach ($groupings[0] as $groupid) {
2145              $groupoverride = $cache->get("{$cm->instance}_g_{$groupid}");
2146              if (isset($groupoverride->timeopen)) {
2147                  $opens[] = $groupoverride->timeopen;
2148              }
2149              if (isset($groupoverride->timeclose)) {
2150                  $closes[] = $groupoverride->timeclose;
2151              }
2152          }
2153          // If there is a user override for a setting, ignore the group override.
2154          if (is_null($override->timeopen) && count($opens)) {
2155              $override->timeopen = min($opens);
2156          }
2157          if (is_null($override->timeclose) && count($closes)) {
2158              if (in_array(0, $closes)) {
2159                  $override->timeclose = 0;
2160              } else {
2161                  $override->timeclose = max($closes);
2162              }
2163          }
2164      }
2165  
2166      // Populate some other values that can be used in calendar or on dashboard.
2167      if (!is_null($override->timeopen)) {
2168          $cm->override_customdata('timeopen', $override->timeopen);
2169      }
2170      if (!is_null($override->timeclose)) {
2171          $cm->override_customdata('timeclose', $override->timeclose);
2172      }
2173  }
2174  
2175  /**
2176   * Callback which returns human-readable strings describing the active completion custom rules for the module instance.
2177   *
2178   * @param cm_info|stdClass $cm object with fields ->completion and ->customdata['customcompletionrules']
2179   * @return array $descriptions the array of descriptions for the custom rules.
2180   */
2181  function mod_quiz_get_completion_active_rule_descriptions($cm) {
2182      // Values will be present in cm_info, and we assume these are up to date.
2183      if (empty($cm->customdata['customcompletionrules'])
2184          || $cm->completion != COMPLETION_TRACKING_AUTOMATIC) {
2185          return [];
2186      }
2187  
2188      $descriptions = [];
2189      $rules = $cm->customdata['customcompletionrules'];
2190  
2191      if (!empty($rules['completionpassorattemptsexhausted'])) {
2192          if (!empty($rules['completionpassorattemptsexhausted']['completionattemptsexhausted'])) {
2193              $descriptions[] = get_string('completionpassorattemptsexhausteddesc', 'quiz');
2194          }
2195      } else {
2196          // Fallback.
2197          if (!empty($rules['completionattemptsexhausted'])) {
2198              $descriptions[] = get_string('completionpassorattemptsexhausteddesc', 'quiz');
2199          }
2200      }
2201  
2202      if (!empty($rules['completionminattempts'])) {
2203          $descriptions[] = get_string('completionminattemptsdesc', 'quiz', $rules['completionminattempts']);
2204      }
2205  
2206      return $descriptions;
2207  }
2208  
2209  /**
2210   * Returns the min and max values for the timestart property of a quiz
2211   * activity event.
2212   *
2213   * The min and max values will be the timeopen and timeclose properties
2214   * of the quiz, respectively, if they are set.
2215   *
2216   * If either value isn't set then null will be returned instead to
2217   * indicate that there is no cutoff for that value.
2218   *
2219   * If the vent has no valid timestart range then [false, false] will
2220   * be returned. This is the case for overriden events.
2221   *
2222   * A minimum and maximum cutoff return value will look like:
2223   * [
2224   *     [1505704373, 'The date must be after this date'],
2225   *     [1506741172, 'The date must be before this date']
2226   * ]
2227   *
2228   * @throws \moodle_exception
2229   * @param \calendar_event $event The calendar event to get the time range for
2230   * @param stdClass $quiz The module instance to get the range from
2231   * @return array
2232   */
2233  function mod_quiz_core_calendar_get_valid_event_timestart_range(\calendar_event $event, \stdClass $quiz) {
2234      global $CFG, $DB;
2235      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
2236  
2237      // Overrides do not have a valid timestart range.
2238      if (quiz_is_overriden_calendar_event($event)) {
2239          return [false, false];
2240      }
2241  
2242      $mindate = null;
2243      $maxdate = null;
2244  
2245      if ($event->eventtype == QUIZ_EVENT_TYPE_OPEN) {
2246          if (!empty($quiz->timeclose)) {
2247              $maxdate = [
2248                  $quiz->timeclose,
2249                  get_string('openafterclose', 'quiz')
2250              ];
2251          }
2252      } else if ($event->eventtype == QUIZ_EVENT_TYPE_CLOSE) {
2253          if (!empty($quiz->timeopen)) {
2254              $mindate = [
2255                  $quiz->timeopen,
2256                  get_string('closebeforeopen', 'quiz')
2257              ];
2258          }
2259      }
2260  
2261      return [$mindate, $maxdate];
2262  }
2263  
2264  /**
2265   * This function will update the quiz module according to the
2266   * event that has been modified.
2267   *
2268   * It will set the timeopen or timeclose value of the quiz instance
2269   * according to the type of event provided.
2270   *
2271   * @throws \moodle_exception
2272   * @param \calendar_event $event A quiz activity calendar event
2273   * @param \stdClass $quiz A quiz activity instance
2274   */
2275  function mod_quiz_core_calendar_event_timestart_updated(\calendar_event $event, \stdClass $quiz) {
2276      global $CFG, $DB;
2277      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
2278  
2279      if (!in_array($event->eventtype, [QUIZ_EVENT_TYPE_OPEN, QUIZ_EVENT_TYPE_CLOSE])) {
2280          // This isn't an event that we care about so we can ignore it.
2281          return;
2282      }
2283  
2284      $courseid = $event->courseid;
2285      $modulename = $event->modulename;
2286      $instanceid = $event->instance;
2287      $modified = false;
2288      $closedatechanged = false;
2289  
2290      // Something weird going on. The event is for a different module so
2291      // we should ignore it.
2292      if ($modulename != 'quiz') {
2293          return;
2294      }
2295  
2296      if ($quiz->id != $instanceid) {
2297          // The provided quiz instance doesn't match the event so
2298          // there is nothing to do here.
2299          return;
2300      }
2301  
2302      // We don't update the activity if it's an override event that has
2303      // been modified.
2304      if (quiz_is_overriden_calendar_event($event)) {
2305          return;
2306      }
2307  
2308      $coursemodule = get_fast_modinfo($courseid)->instances[$modulename][$instanceid];
2309      $context = context_module::instance($coursemodule->id);
2310  
2311      // The user does not have the capability to modify this activity.
2312      if (!has_capability('moodle/course:manageactivities', $context)) {
2313          return;
2314      }
2315  
2316      if ($event->eventtype == QUIZ_EVENT_TYPE_OPEN) {
2317          // If the event is for the quiz activity opening then we should
2318          // set the start time of the quiz activity to be the new start
2319          // time of the event.
2320          if ($quiz->timeopen != $event->timestart) {
2321              $quiz->timeopen = $event->timestart;
2322              $modified = true;
2323          }
2324      } else if ($event->eventtype == QUIZ_EVENT_TYPE_CLOSE) {
2325          // If the event is for the quiz activity closing then we should
2326          // set the end time of the quiz activity to be the new start
2327          // time of the event.
2328          if ($quiz->timeclose != $event->timestart) {
2329              $quiz->timeclose = $event->timestart;
2330              $modified = true;
2331              $closedatechanged = true;
2332          }
2333      }
2334  
2335      if ($modified) {
2336          $quiz->timemodified = time();
2337          $DB->update_record('quiz', $quiz);
2338  
2339          if ($closedatechanged) {
2340              quiz_update_open_attempts(array('quizid' => $quiz->id));
2341          }
2342  
2343          // Delete any previous preview attempts.
2344          quiz_delete_previews($quiz);
2345          quiz_update_events($quiz);
2346          $event = \core\event\course_module_updated::create_from_cm($coursemodule, $context);
2347          $event->trigger();
2348      }
2349  }
2350  
2351  /**
2352   * Generates the question bank in a fragment output. This allows
2353   * the question bank to be displayed in a modal.
2354   *
2355   * The only expected argument provided in the $args array is
2356   * 'querystring'. The value should be the list of parameters
2357   * URL encoded and used to build the question bank page.
2358   *
2359   * The individual list of parameters expected can be found in
2360   * question_build_edit_resources.
2361   *
2362   * @param array $args The fragment arguments.
2363   * @return string The rendered mform fragment.
2364   */
2365  function mod_quiz_output_fragment_quiz_question_bank($args) {
2366      global $CFG, $DB, $PAGE;
2367      require_once($CFG->dirroot . '/mod/quiz/locallib.php');
2368      require_once($CFG->dirroot . '/question/editlib.php');
2369  
2370      $querystring = preg_replace('/^\?/', '', $args['querystring']);
2371      $params = [];
2372      parse_str($querystring, $params);
2373  
2374      // Build the required resources. The $params are all cleaned as
2375      // part of this process.
2376      list($thispageurl, $contexts, $cmid, $cm, $quiz, $pagevars) =
2377              question_build_edit_resources('editq', '/mod/quiz/edit.php', $params);
2378  
2379      // Get the course object and related bits.
2380      $course = $DB->get_record('course', array('id' => $quiz->course), '*', MUST_EXIST);
2381      require_capability('mod/quiz:manage', $contexts->lowest());
2382  
2383      // Create quiz question bank view.
2384      $questionbank = new mod_quiz\question\bank\custom_view($contexts, $thispageurl, $course, $cm, $quiz);
2385      $questionbank->set_quiz_has_attempts(quiz_has_attempts($quiz->id));
2386  
2387      // Output.
2388      $renderer = $PAGE->get_renderer('mod_quiz', 'edit');
2389      return $renderer->question_bank_contents($questionbank, $pagevars);
2390  }
2391  
2392  /**
2393   * Generates the add random question in a fragment output. This allows the
2394   * form to be rendered in javascript, for example inside a modal.
2395   *
2396   * The required arguments as keys in the $args array are:
2397   *      cat {string} The category and category context ids comma separated.
2398   *      addonpage {int} The page id to add this question to.
2399   *      returnurl {string} URL to return to after form submission.
2400   *      cmid {int} The course module id the questions are being added to.
2401   *
2402   * @param array $args The fragment arguments.
2403   * @return string The rendered mform fragment.
2404   */
2405  function mod_quiz_output_fragment_add_random_question_form($args) {
2406      global $CFG;
2407      require_once($CFG->dirroot . '/mod/quiz/addrandomform.php');
2408  
2409      $contexts = new \core_question\local\bank\question_edit_contexts($args['context']);
2410      $formoptions = [
2411          'contexts' => $contexts,
2412          'cat' => $args['cat']
2413      ];
2414      $formdata = [
2415          'category' => $args['cat'],
2416          'addonpage' => $args['addonpage'],
2417          'returnurl' => $args['returnurl'],
2418          'cmid' => $args['cmid']
2419      ];
2420  
2421      $form = new quiz_add_random_form(
2422          new \moodle_url('/mod/quiz/addrandom.php'),
2423          $formoptions,
2424          'post',
2425          '',
2426          null,
2427          true,
2428          $formdata
2429      );
2430      $form->set_data($formdata);
2431  
2432      return $form->render();
2433  }
2434  
2435  /**
2436   * Callback to fetch the activity event type lang string.
2437   *
2438   * @param string $eventtype The event type.
2439   * @return lang_string The event type lang string.
2440   */
2441  function mod_quiz_core_calendar_get_event_action_string(string $eventtype): string {
2442      $modulename = get_string('modulename', 'quiz');
2443  
2444      switch ($eventtype) {
2445          case QUIZ_EVENT_TYPE_OPEN:
2446              $identifier = 'quizeventopens';
2447              break;
2448          case QUIZ_EVENT_TYPE_CLOSE:
2449              $identifier = 'quizeventcloses';
2450              break;
2451          default:
2452              return get_string('requiresaction', 'calendar', $modulename);
2453      }
2454  
2455      return get_string($identifier, 'quiz', $modulename);
2456  }
2457  
2458  /**
2459   * Delete question reference data.
2460   *
2461   * @param int $quizid The id of quiz.
2462   */
2463  function quiz_delete_references($quizid): void {
2464      global $DB;
2465      $slots = $DB->get_records('quiz_slots', ['quizid' => $quizid]);
2466      foreach ($slots as $slot) {
2467          $params = [
2468              'itemid' => $slot->id,
2469              'component' => 'mod_quiz',
2470              'questionarea' => 'slot'
2471          ];
2472          // Delete any set references.
2473          $DB->delete_records('question_set_references', $params);
2474          // Delete any references.
2475          $DB->delete_records('question_references', $params);
2476      }
2477  }
2478  
2479  /**
2480   * Implement the calculate_question_stats callback.
2481   *
2482   * This enables quiz statistics to be shown in statistics columns in the database.
2483   *
2484   * @param context $context return the statistics related to this context (which will be a quiz context).
2485   * @return all_calculated_for_qubaid_condition|null The statistics for this quiz, if available, else null.
2486   */
2487  function mod_quiz_calculate_question_stats(context $context): ?all_calculated_for_qubaid_condition {
2488      global $CFG;
2489      require_once($CFG->dirroot . '/mod/quiz/report/statistics/report.php');
2490      $cm = get_coursemodule_from_id('quiz', $context->instanceid);
2491      $report = new quiz_statistics_report();
2492      return $report->calculate_questions_stats_for_question_bank($cm->instance, false);
2493  }