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  • Bug fixes for general core bugs in 3.11.x will end 9 May 2022 (12 months).
  • Bug fixes for security issues in 3.11.x will end 14 November 2022 (18 months).
  • PHP version: minimum PHP 7.3.0 Note: minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is supported too.
  • /mod/forum/ -> lib.php (source)

    Differences Between: [Versions 310 and 311] [Versions 35 and 311] [Versions 36 and 311] [Versions 37 and 311] [Versions 38 and 311] [Versions 39 and 311]

       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   * @package   mod_forum
      19   * @copyright 1999 onwards Martin Dougiamas  {@link http://moodle.com}
      20   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
      21   */
      22  
      23  defined('MOODLE_INTERNAL') || die();
      24  
      25  /** Include required files */
      26  require_once (__DIR__ . '/deprecatedlib.php');
      27  require_once($CFG->libdir.'/filelib.php');
      28  
      29  /// CONSTANTS ///////////////////////////////////////////////////////////
      30  
      31  define('FORUM_MODE_FLATOLDEST', 1);
      32  define('FORUM_MODE_FLATNEWEST', -1);
      33  define('FORUM_MODE_THREADED', 2);
      34  define('FORUM_MODE_NESTED', 3);
      35  define('FORUM_MODE_NESTED_V2', 4);
      36  
      37  define('FORUM_CHOOSESUBSCRIBE', 0);
      38  define('FORUM_FORCESUBSCRIBE', 1);
      39  define('FORUM_INITIALSUBSCRIBE', 2);
      40  define('FORUM_DISALLOWSUBSCRIBE',3);
      41  
      42  /**
      43   * FORUM_TRACKING_OFF - Tracking is not available for this forum.
      44   */
      45  define('FORUM_TRACKING_OFF', 0);
      46  
      47  /**
      48   * FORUM_TRACKING_OPTIONAL - Tracking is based on user preference.
      49   */
      50  define('FORUM_TRACKING_OPTIONAL', 1);
      51  
      52  /**
      53   * FORUM_TRACKING_FORCED - Tracking is on, regardless of user setting.
      54   * Treated as FORUM_TRACKING_OPTIONAL if $CFG->forum_allowforcedreadtracking is off.
      55   */
      56  define('FORUM_TRACKING_FORCED', 2);
      57  
      58  define('FORUM_MAILED_PENDING', 0);
      59  define('FORUM_MAILED_SUCCESS', 1);
      60  define('FORUM_MAILED_ERROR', 2);
      61  
      62  if (!defined('FORUM_CRON_USER_CACHE')) {
      63      /** Defines how many full user records are cached in forum cron. */
      64      define('FORUM_CRON_USER_CACHE', 5000);
      65  }
      66  
      67  /**
      68   * FORUM_POSTS_ALL_USER_GROUPS - All the posts in groups where the user is enrolled.
      69   */
      70  define('FORUM_POSTS_ALL_USER_GROUPS', -2);
      71  
      72  define('FORUM_DISCUSSION_PINNED', 1);
      73  define('FORUM_DISCUSSION_UNPINNED', 0);
      74  
      75  /// STANDARD FUNCTIONS ///////////////////////////////////////////////////////////
      76  
      77  /**
      78   * Given an object containing all the necessary data,
      79   * (defined by the form in mod_form.php) this function
      80   * will create a new instance and return the id number
      81   * of the new instance.
      82   *
      83   * @param stdClass $forum add forum instance
      84   * @param mod_forum_mod_form $mform
      85   * @return int intance id
      86   */
      87  function forum_add_instance($forum, $mform = null) {
      88      global $CFG, $DB;
      89  
      90      require_once($CFG->dirroot.'/mod/forum/locallib.php');
      91  
      92      $forum->timemodified = time();
      93  
      94      if (empty($forum->assessed)) {
      95          $forum->assessed = 0;
      96      }
      97  
      98      if (empty($forum->ratingtime) or empty($forum->assessed)) {
      99          $forum->assesstimestart  = 0;
     100          $forum->assesstimefinish = 0;
     101      }
     102  
     103      $forum->id = $DB->insert_record('forum', $forum);
     104      $modcontext = context_module::instance($forum->coursemodule);
     105  
     106      if ($forum->type == 'single') {  // Create related discussion.
     107          $discussion = new stdClass();
     108          $discussion->course        = $forum->course;
     109          $discussion->forum         = $forum->id;
     110          $discussion->name          = $forum->name;
     111          $discussion->assessed      = $forum->assessed;
     112          $discussion->message       = $forum->intro;
     113          $discussion->messageformat = $forum->introformat;
     114          $discussion->messagetrust  = trusttext_trusted(context_course::instance($forum->course));
     115          $discussion->mailnow       = false;
     116          $discussion->groupid       = -1;
     117  
     118          $message = '';
     119  
     120          $discussion->id = forum_add_discussion($discussion, null, $message);
     121  
     122          if ($mform and $draftid = file_get_submitted_draft_itemid('introeditor')) {
     123              // Ugly hack - we need to copy the files somehow.
     124              $discussion = $DB->get_record('forum_discussions', array('id'=>$discussion->id), '*', MUST_EXIST);
     125              $post = $DB->get_record('forum_posts', array('id'=>$discussion->firstpost), '*', MUST_EXIST);
     126  
     127              $options = array('subdirs'=>true); // Use the same options as intro field!
     128              $post->message = file_save_draft_area_files($draftid, $modcontext->id, 'mod_forum', 'post', $post->id, $options, $post->message);
     129              $DB->set_field('forum_posts', 'message', $post->message, array('id'=>$post->id));
     130          }
     131      }
     132  
     133      forum_update_calendar($forum, $forum->coursemodule);
     134      forum_grade_item_update($forum);
     135  
     136      $completiontimeexpected = !empty($forum->completionexpected) ? $forum->completionexpected : null;
     137      \core_completion\api::update_completion_date_event($forum->coursemodule, 'forum', $forum->id, $completiontimeexpected);
     138  
     139      return $forum->id;
     140  }
     141  
     142  /**
     143   * Handle changes following the creation of a forum instance.
     144   * This function is typically called by the course_module_created observer.
     145   *
     146   * @param object $context the forum context
     147   * @param stdClass $forum The forum object
     148   * @return void
     149   */
     150  function forum_instance_created($context, $forum) {
     151      if ($forum->forcesubscribe == FORUM_INITIALSUBSCRIBE) {
     152          $users = \mod_forum\subscriptions::get_potential_subscribers($context, 0, 'u.id, u.email');
     153          foreach ($users as $user) {
     154              \mod_forum\subscriptions::subscribe_user($user->id, $forum, $context);
     155          }
     156      }
     157  }
     158  
     159  /**
     160   * Given an object containing all the necessary data,
     161   * (defined by the form in mod_form.php) this function
     162   * will update an existing instance with new data.
     163   *
     164   * @global object
     165   * @param object $forum forum instance (with magic quotes)
     166   * @return bool success
     167   */
     168  function forum_update_instance($forum, $mform) {
     169      global $CFG, $DB, $OUTPUT, $USER;
     170  
     171      require_once($CFG->dirroot.'/mod/forum/locallib.php');
     172  
     173      $forum->timemodified = time();
     174      $forum->id           = $forum->instance;
     175  
     176      if (empty($forum->assessed)) {
     177          $forum->assessed = 0;
     178      }
     179  
     180      if (empty($forum->ratingtime) or empty($forum->assessed)) {
     181          $forum->assesstimestart  = 0;
     182          $forum->assesstimefinish = 0;
     183      }
     184  
     185      $oldforum = $DB->get_record('forum', array('id'=>$forum->id));
     186  
     187      // MDL-3942 - if the aggregation type or scale (i.e. max grade) changes then recalculate the grades for the entire forum
     188      // if  scale changes - do we need to recheck the ratings, if ratings higher than scale how do we want to respond?
     189      // for count and sum aggregation types the grade we check to make sure they do not exceed the scale (i.e. max score) when calculating the grade
     190      $updategrades = false;
     191  
     192      if ($oldforum->assessed <> $forum->assessed) {
     193          // Whether this forum is rated.
     194          $updategrades = true;
     195      }
     196  
     197      if ($oldforum->scale <> $forum->scale) {
     198          // The scale currently in use.
     199          $updategrades = true;
     200      }
     201  
     202      if (empty($oldforum->grade_forum) || $oldforum->grade_forum <> $forum->grade_forum) {
     203          // The whole forum grading.
     204          $updategrades = true;
     205      }
     206  
     207      if ($updategrades) {
     208          forum_update_grades($forum); // Recalculate grades for the forum.
     209      }
     210  
     211      if ($forum->type == 'single') {  // Update related discussion and post.
     212          $discussions = $DB->get_records('forum_discussions', array('forum'=>$forum->id), 'timemodified ASC');
     213          if (!empty($discussions)) {
     214              if (count($discussions) > 1) {
     215                  echo $OUTPUT->notification(get_string('warnformorepost', 'forum'));
     216              }
     217              $discussion = array_pop($discussions);
     218          } else {
     219              // try to recover by creating initial discussion - MDL-16262
     220              $discussion = new stdClass();
     221              $discussion->course          = $forum->course;
     222              $discussion->forum           = $forum->id;
     223              $discussion->name            = $forum->name;
     224              $discussion->assessed        = $forum->assessed;
     225              $discussion->message         = $forum->intro;
     226              $discussion->messageformat   = $forum->introformat;
     227              $discussion->messagetrust    = true;
     228              $discussion->mailnow         = false;
     229              $discussion->groupid         = -1;
     230  
     231              $message = '';
     232  
     233              forum_add_discussion($discussion, null, $message);
     234  
     235              if (! $discussion = $DB->get_record('forum_discussions', array('forum'=>$forum->id))) {
     236                  print_error('cannotadd', 'forum');
     237              }
     238          }
     239          if (! $post = $DB->get_record('forum_posts', array('id'=>$discussion->firstpost))) {
     240              print_error('cannotfindfirstpost', 'forum');
     241          }
     242  
     243          $cm         = get_coursemodule_from_instance('forum', $forum->id);
     244          $modcontext = context_module::instance($cm->id, MUST_EXIST);
     245  
     246          $post = $DB->get_record('forum_posts', array('id'=>$discussion->firstpost), '*', MUST_EXIST);
     247          $post->subject       = $forum->name;
     248          $post->message       = $forum->intro;
     249          $post->messageformat = $forum->introformat;
     250          $post->messagetrust  = trusttext_trusted($modcontext);
     251          $post->modified      = $forum->timemodified;
     252          $post->userid        = $USER->id;    // MDL-18599, so that current teacher can take ownership of activities.
     253  
     254          if ($mform and $draftid = file_get_submitted_draft_itemid('introeditor')) {
     255              // Ugly hack - we need to copy the files somehow.
     256              $options = array('subdirs'=>true); // Use the same options as intro field!
     257              $post->message = file_save_draft_area_files($draftid, $modcontext->id, 'mod_forum', 'post', $post->id, $options, $post->message);
     258          }
     259  
     260          \mod_forum\local\entities\post::add_message_counts($post);
     261          $DB->update_record('forum_posts', $post);
     262          $discussion->name = $forum->name;
     263          $DB->update_record('forum_discussions', $discussion);
     264      }
     265  
     266      $DB->update_record('forum', $forum);
     267  
     268      $modcontext = context_module::instance($forum->coursemodule);
     269      if (($forum->forcesubscribe == FORUM_INITIALSUBSCRIBE) && ($oldforum->forcesubscribe <> $forum->forcesubscribe)) {
     270          $users = \mod_forum\subscriptions::get_potential_subscribers($modcontext, 0, 'u.id, u.email', '');
     271          foreach ($users as $user) {
     272              \mod_forum\subscriptions::subscribe_user($user->id, $forum, $modcontext);
     273          }
     274      }
     275  
     276      forum_update_calendar($forum, $forum->coursemodule);
     277      forum_grade_item_update($forum);
     278  
     279      $completiontimeexpected = !empty($forum->completionexpected) ? $forum->completionexpected : null;
     280      \core_completion\api::update_completion_date_event($forum->coursemodule, 'forum', $forum->id, $completiontimeexpected);
     281  
     282      return true;
     283  }
     284  
     285  
     286  /**
     287   * Given an ID of an instance of this module,
     288   * this function will permanently delete the instance
     289   * and any data that depends on it.
     290   *
     291   * @global object
     292   * @param int $id forum instance id
     293   * @return bool success
     294   */
     295  function forum_delete_instance($id) {
     296      global $DB;
     297  
     298      if (!$forum = $DB->get_record('forum', array('id'=>$id))) {
     299          return false;
     300      }
     301      if (!$cm = get_coursemodule_from_instance('forum', $forum->id)) {
     302          return false;
     303      }
     304      if (!$course = $DB->get_record('course', array('id'=>$cm->course))) {
     305          return false;
     306      }
     307  
     308      $context = context_module::instance($cm->id);
     309  
     310      // now get rid of all files
     311      $fs = get_file_storage();
     312      $fs->delete_area_files($context->id);
     313  
     314      $result = true;
     315  
     316      \core_completion\api::update_completion_date_event($cm->id, 'forum', $forum->id, null);
     317  
     318      // Delete digest and subscription preferences.
     319      $DB->delete_records('forum_digests', array('forum' => $forum->id));
     320      $DB->delete_records('forum_subscriptions', array('forum'=>$forum->id));
     321      $DB->delete_records('forum_discussion_subs', array('forum' => $forum->id));
     322  
     323      if ($discussions = $DB->get_records('forum_discussions', array('forum'=>$forum->id))) {
     324          foreach ($discussions as $discussion) {
     325              if (!forum_delete_discussion($discussion, true, $course, $cm, $forum)) {
     326                  $result = false;
     327              }
     328          }
     329      }
     330  
     331      forum_tp_delete_read_records(-1, -1, -1, $forum->id);
     332  
     333      forum_grade_item_delete($forum);
     334  
     335      // We must delete the module record after we delete the grade item.
     336      if (!$DB->delete_records('forum', array('id'=>$forum->id))) {
     337          $result = false;
     338      }
     339  
     340      return $result;
     341  }
     342  
     343  
     344  /**
     345   * Indicates API features that the forum supports.
     346   *
     347   * @uses FEATURE_GROUPS
     348   * @uses FEATURE_GROUPINGS
     349   * @uses FEATURE_MOD_INTRO
     350   * @uses FEATURE_COMPLETION_TRACKS_VIEWS
     351   * @uses FEATURE_COMPLETION_HAS_RULES
     352   * @uses FEATURE_GRADE_HAS_GRADE
     353   * @uses FEATURE_GRADE_OUTCOMES
     354   * @param string $feature
     355   * @return mixed True if yes (some features may use other values)
     356   */
     357  function forum_supports($feature) {
     358      switch($feature) {
     359          case FEATURE_GROUPS:                  return true;
     360          case FEATURE_GROUPINGS:               return true;
     361          case FEATURE_MOD_INTRO:               return true;
     362          case FEATURE_COMPLETION_TRACKS_VIEWS: return true;
     363          case FEATURE_COMPLETION_HAS_RULES:    return true;
     364          case FEATURE_GRADE_HAS_GRADE:         return true;
     365          case FEATURE_GRADE_OUTCOMES:          return true;
     366          case FEATURE_RATE:                    return true;
     367          case FEATURE_BACKUP_MOODLE2:          return true;
     368          case FEATURE_SHOW_DESCRIPTION:        return true;
     369          case FEATURE_PLAGIARISM:              return true;
     370          case FEATURE_ADVANCED_GRADING:        return true;
     371  
     372          default: return null;
     373      }
     374  }
     375  
     376  /**
     377   * Create a message-id string to use in the custom headers of forum notification emails
     378   *
     379   * message-id is used by email clients to identify emails and to nest conversations
     380   *
     381   * @param int $postid The ID of the forum post we are notifying the user about
     382   * @param int $usertoid The ID of the user being notified
     383   * @return string A unique message-id
     384   */
     385  function forum_get_email_message_id($postid, $usertoid) {
     386      return generate_email_messageid(hash('sha256', $postid . 'to' . $usertoid));
     387  }
     388  
     389  /**
     390   *
     391   * @param object $course
     392   * @param object $user
     393   * @param object $mod TODO this is not used in this function, refactor
     394   * @param object $forum
     395   * @return object A standard object with 2 variables: info (number of posts for this user) and time (last modified)
     396   */
     397  function forum_user_outline($course, $user, $mod, $forum) {
     398      global $CFG;
     399      require_once("$CFG->libdir/gradelib.php");
     400  
     401      $gradeinfo = '';
     402      $gradetime = 0;
     403  
     404      $grades = grade_get_grades($course->id, 'mod', 'forum', $forum->id, $user->id);
     405      if (!empty($grades->items[0]->grades)) {
     406          // Item 0 is the rating.
     407          $grade = reset($grades->items[0]->grades);
     408          $gradetime = max($gradetime, grade_get_date_for_user_grade($grade, $user));
     409          if (!$grade->hidden || has_capability('moodle/grade:viewhidden', context_course::instance($course->id))) {
     410              $gradeinfo .= get_string('gradeforrating', 'forum', $grade) .  html_writer::empty_tag('br');
     411          } else {
     412              $gradeinfo .= get_string('gradeforratinghidden', 'forum') . html_writer::empty_tag('br');
     413          }
     414      }
     415  
     416      // Item 1 is the whole-forum grade.
     417      if (!empty($grades->items[1]->grades)) {
     418          $grade = reset($grades->items[1]->grades);
     419          $gradetime = max($gradetime, grade_get_date_for_user_grade($grade, $user));
     420          if (!$grade->hidden || has_capability('moodle/grade:viewhidden', context_course::instance($course->id))) {
     421              $gradeinfo .= get_string('gradeforwholeforum', 'forum', $grade) .  html_writer::empty_tag('br');
     422          } else {
     423              $gradeinfo .= get_string('gradeforwholeforumhidden', 'forum') . html_writer::empty_tag('br');
     424          }
     425      }
     426  
     427      $count = forum_count_user_posts($forum->id, $user->id);
     428      if ($count && $count->postcount > 0) {
     429          $info = get_string("numposts", "forum", $count->postcount);
     430          $time = $count->lastpost;
     431  
     432          if ($gradeinfo) {
     433              $info .= ', ' . $gradeinfo;
     434              $time = max($time, $gradetime);
     435          }
     436  
     437          return (object) [
     438              'info' => $info,
     439              'time' => $time,
     440          ];
     441      } else if ($gradeinfo) {
     442          return (object) [
     443              'info' => $gradeinfo,
     444              'time' => $gradetime,
     445          ];
     446      }
     447  
     448      return null;
     449  }
     450  
     451  
     452  /**
     453   * @global object
     454   * @global object
     455   * @param object $coure
     456   * @param object $user
     457   * @param object $mod
     458   * @param object $forum
     459   */
     460  function forum_user_complete($course, $user, $mod, $forum) {
     461      global $CFG, $USER;
     462      require_once("$CFG->libdir/gradelib.php");
     463  
     464      $getgradeinfo = function($grades, string $type) use ($course): string {
     465          global $OUTPUT;
     466  
     467          if (empty($grades)) {
     468              return '';
     469          }
     470  
     471          $result = '';
     472          $grade = reset($grades);
     473          if (!$grade->hidden || has_capability('moodle/grade:viewhidden', context_course::instance($course->id))) {
     474              $result .= $OUTPUT->container(get_string("gradefor{$type}", "forum", $grade));
     475              if ($grade->str_feedback) {
     476                  $result .= $OUTPUT->container(get_string('feedback').': '.$grade->str_feedback);
     477              }
     478          } else {
     479              $result .= $OUTPUT->container(get_string("gradefor{$type}hidden", "forum"));
     480          }
     481  
     482          return $result;
     483      };
     484  
     485      $grades = grade_get_grades($course->id, 'mod', 'forum', $forum->id, $user->id);
     486  
     487      // Item 0 is the rating.
     488      if (!empty($grades->items[0]->grades)) {
     489          echo $getgradeinfo($grades->items[0]->grades, 'rating');
     490      }
     491  
     492      // Item 1 is the whole-forum grade.
     493      if (!empty($grades->items[1]->grades)) {
     494          echo $getgradeinfo($grades->items[1]->grades, 'wholeforum');
     495      }
     496  
     497      if ($posts = forum_get_user_posts($forum->id, $user->id)) {
     498          if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id)) {
     499              print_error('invalidcoursemodule');
     500          }
     501          $context = context_module::instance($cm->id);
     502          $discussions = forum_get_user_involved_discussions($forum->id, $user->id);
     503          $posts = array_filter($posts, function($post) use ($discussions) {
     504              return isset($discussions[$post->discussion]);
     505          });
     506          $entityfactory = mod_forum\local\container::get_entity_factory();
     507          $rendererfactory = mod_forum\local\container::get_renderer_factory();
     508          $postrenderer = $rendererfactory->get_posts_renderer();
     509  
     510          echo $postrenderer->render(
     511              $USER,
     512              [$forum->id => $entityfactory->get_forum_from_stdclass($forum, $context, $cm, $course)],
     513              array_map(function($discussion) use ($entityfactory) {
     514                  return $entityfactory->get_discussion_from_stdclass($discussion);
     515              }, $discussions),
     516              array_map(function($post) use ($entityfactory) {
     517                  return $entityfactory->get_post_from_stdclass($post);
     518              }, $posts)
     519          );
     520      } else {
     521          echo "<p>".get_string("noposts", "forum")."</p>";
     522      }
     523  }
     524  
     525  /**
     526   * @deprecated since Moodle 3.3, when the block_course_overview block was removed.
     527   */
     528  function forum_filter_user_groups_discussions() {
     529      throw new coding_exception('forum_filter_user_groups_discussions() can not be used any more and is obsolete.');
     530  }
     531  
     532  /**
     533   * Returns whether the discussion group is visible by the current user or not.
     534   *
     535   * @since Moodle 2.8, 2.7.1, 2.6.4
     536   * @param cm_info $cm The discussion course module
     537   * @param int $discussiongroupid The discussion groupid
     538   * @return bool
     539   */
     540  function forum_is_user_group_discussion(cm_info $cm, $discussiongroupid) {
     541  
     542      if ($discussiongroupid == -1 || $cm->effectivegroupmode != SEPARATEGROUPS) {
     543          return true;
     544      }
     545  
     546      if (isguestuser()) {
     547          return false;
     548      }
     549  
     550      if (has_capability('moodle/site:accessallgroups', context_module::instance($cm->id)) ||
     551              in_array($discussiongroupid, $cm->get_modinfo()->get_groups($cm->groupingid))) {
     552          return true;
     553      }
     554  
     555      return false;
     556  }
     557  
     558  /**
     559   * @deprecated since Moodle 3.3, when the block_course_overview block was removed.
     560   */
     561  function forum_print_overview() {
     562      throw new coding_exception('forum_print_overview() can not be used any more and is obsolete.');
     563  }
     564  
     565  /**
     566   * Given a course and a date, prints a summary of all the new
     567   * messages posted in the course since that date
     568   *
     569   * @global object
     570   * @global object
     571   * @global object
     572   * @uses CONTEXT_MODULE
     573   * @uses VISIBLEGROUPS
     574   * @param object $course
     575   * @param bool $viewfullnames capability
     576   * @param int $timestart
     577   * @return bool success
     578   */
     579  function forum_print_recent_activity($course, $viewfullnames, $timestart) {
     580      global $USER, $DB, $OUTPUT;
     581  
     582      // do not use log table if possible, it may be huge and is expensive to join with other tables
     583  
     584      $userfieldsapi = \core_user\fields::for_userpic();
     585      $allnamefields = $userfieldsapi->get_sql('u', false, '', 'duserid', false)->selects;
     586      if (!$posts = $DB->get_records_sql("SELECT p.*,
     587                                                f.course, f.type AS forumtype, f.name AS forumname, f.intro, f.introformat, f.duedate,
     588                                                f.cutoffdate, f.assessed AS forumassessed, f.assesstimestart, f.assesstimefinish,
     589                                                f.scale, f.grade_forum, f.maxbytes, f.maxattachments, f.forcesubscribe,
     590                                                f.trackingtype, f.rsstype, f.rssarticles, f.timemodified, f.warnafter, f.blockafter,
     591                                                f.blockperiod, f.completiondiscussions, f.completionreplies, f.completionposts,
     592                                                f.displaywordcount, f.lockdiscussionafter, f.grade_forum_notify,
     593                                                d.name AS discussionname, d.firstpost, d.userid AS discussionstarter,
     594                                                d.assessed AS discussionassessed, d.timemodified, d.usermodified, d.forum, d.groupid,
     595                                                d.timestart, d.timeend, d.pinned, d.timelocked,
     596                                                $allnamefields
     597                                           FROM {forum_posts} p
     598                                                JOIN {forum_discussions} d ON d.id = p.discussion
     599                                                JOIN {forum} f             ON f.id = d.forum
     600                                                JOIN {user} u              ON u.id = p.userid
     601                                          WHERE p.created > ? AND f.course = ? AND p.deleted <> 1
     602                                       ORDER BY p.id ASC", array($timestart, $course->id))) { // order by initial posting date
     603           return false;
     604      }
     605  
     606      $modinfo = get_fast_modinfo($course);
     607  
     608      $strftimerecent = get_string('strftimerecent');
     609  
     610      $managerfactory = mod_forum\local\container::get_manager_factory();
     611      $entityfactory = mod_forum\local\container::get_entity_factory();
     612  
     613      $discussions = [];
     614      $capmanagers = [];
     615      $printposts = [];
     616      foreach ($posts as $post) {
     617          if (!isset($modinfo->instances['forum'][$post->forum])) {
     618              // not visible
     619              continue;
     620          }
     621          $cm = $modinfo->instances['forum'][$post->forum];
     622          if (!$cm->uservisible) {
     623              continue;
     624          }
     625  
     626          // Get the discussion. Cache if not yet available.
     627          if (!isset($discussions[$post->discussion])) {
     628              // Build the discussion record object from the post data.
     629              $discussionrecord = (object)[
     630                  'id' => $post->discussion,
     631                  'course' => $post->course,
     632                  'forum' => $post->forum,
     633                  'name' => $post->discussionname,
     634                  'firstpost' => $post->firstpost,
     635                  'userid' => $post->discussionstarter,
     636                  'groupid' => $post->groupid,
     637                  'assessed' => $post->discussionassessed,
     638                  'timemodified' => $post->timemodified,
     639                  'usermodified' => $post->usermodified,
     640                  'timestart' => $post->timestart,
     641                  'timeend' => $post->timeend,
     642                  'pinned' => $post->pinned,
     643                  'timelocked' => $post->timelocked
     644              ];
     645              // Build the discussion entity from the factory and cache it.
     646              $discussions[$post->discussion] = $entityfactory->get_discussion_from_stdclass($discussionrecord);
     647          }
     648          $discussionentity = $discussions[$post->discussion];
     649  
     650          // Get the capability manager. Cache if not yet available.
     651          if (!isset($capmanagers[$post->forum])) {
     652              $context = context_module::instance($cm->id);
     653              $coursemodule = $cm->get_course_module_record();
     654              // Build the forum record object from the post data.
     655              $forumrecord = (object)[
     656                  'id' => $post->forum,
     657                  'course' => $post->course,
     658                  'type' => $post->forumtype,
     659                  'name' => $post->forumname,
     660                  'intro' => $post->intro,
     661                  'introformat' => $post->introformat,
     662                  'duedate' => $post->duedate,
     663                  'cutoffdate' => $post->cutoffdate,
     664                  'assessed' => $post->forumassessed,
     665                  'assesstimestart' => $post->assesstimestart,
     666                  'assesstimefinish' => $post->assesstimefinish,
     667                  'scale' => $post->scale,
     668                  'grade_forum' => $post->grade_forum,
     669                  'maxbytes' => $post->maxbytes,
     670                  'maxattachments' => $post->maxattachments,
     671                  'forcesubscribe' => $post->forcesubscribe,
     672                  'trackingtype' => $post->trackingtype,
     673                  'rsstype' => $post->rsstype,
     674                  'rssarticles' => $post->rssarticles,
     675                  'timemodified' => $post->timemodified,
     676                  'warnafter' => $post->warnafter,
     677                  'blockafter' => $post->blockafter,
     678                  'blockperiod' => $post->blockperiod,
     679                  'completiondiscussions' => $post->completiondiscussions,
     680                  'completionreplies' => $post->completionreplies,
     681                  'completionposts' => $post->completionposts,
     682                  'displaywordcount' => $post->displaywordcount,
     683                  'lockdiscussionafter' => $post->lockdiscussionafter,
     684                  'grade_forum_notify' => $post->grade_forum_notify
     685              ];
     686              // Build the forum entity from the factory.
     687              $forumentity = $entityfactory->get_forum_from_stdclass($forumrecord, $context, $coursemodule, $course);
     688              // Get the capability manager of this forum and cache it.
     689              $capmanagers[$post->forum] = $managerfactory->get_capability_manager($forumentity);
     690          }
     691          $capabilitymanager = $capmanagers[$post->forum];
     692  
     693          // Get the post entity.
     694          $postentity = $entityfactory->get_post_from_stdclass($post);
     695  
     696          // Check if the user can view the post.
     697          if ($capabilitymanager->can_view_post($USER, $discussionentity, $postentity)) {
     698              $printposts[] = $post;
     699          }
     700      }
     701      unset($posts);
     702  
     703      if (!$printposts) {
     704          return false;
     705      }
     706  
     707      echo $OUTPUT->heading(get_string('newforumposts', 'forum') . ':', 6);
     708      $list = html_writer::start_tag('ul', ['class' => 'unlist']);
     709  
     710      foreach ($printposts as $post) {
     711          $subjectclass = empty($post->parent) ? ' bold' : '';
     712          $authorhidden = forum_is_author_hidden($post, (object) ['type' => $post->forumtype]);
     713  
     714          $list .= html_writer::start_tag('li');
     715          $list .= html_writer::start_div('head');
     716          $list .= html_writer::div(userdate_htmltime($post->modified, $strftimerecent), 'date');
     717          if (!$authorhidden) {
     718              $list .= html_writer::div(fullname($post, $viewfullnames), 'name');
     719          }
     720          $list .= html_writer::end_div(); // Head.
     721  
     722          $list .= html_writer::start_div('info' . $subjectclass);
     723          $discussionurl = new moodle_url('/mod/forum/discuss.php', ['d' => $post->discussion]);
     724          if (!empty($post->parent)) {
     725              $discussionurl->param('parent', $post->parent);
     726              $discussionurl->set_anchor('p'. $post->id);
     727          }
     728          $post->subject = break_up_long_words(format_string($post->subject, true));
     729          $list .= html_writer::link($discussionurl, $post->subject, ['rel' => 'bookmark']);
     730          $list .= html_writer::end_div(); // Info.
     731          $list .= html_writer::end_tag('li');
     732      }
     733  
     734      $list .= html_writer::end_tag('ul');
     735      echo $list;
     736  
     737      return true;
     738  }
     739  
     740  /**
     741   * Update activity grades.
     742   *
     743   * @param object $forum
     744   * @param int $userid specific user only, 0 means all
     745   */
     746  function forum_update_grades($forum, $userid = 0): void {
     747      global $CFG, $DB;
     748      require_once($CFG->libdir.'/gradelib.php');
     749  
     750      $ratings = null;
     751      if ($forum->assessed) {
     752          require_once($CFG->dirroot.'/rating/lib.php');
     753  
     754          $cm = get_coursemodule_from_instance('forum', $forum->id);
     755  
     756          $rm = new rating_manager();
     757          $ratings = $rm->get_user_grades((object) [
     758              'component' => 'mod_forum',
     759              'ratingarea' => 'post',
     760              'contextid' => \context_module::instance($cm->id)->id,
     761  
     762              'modulename' => 'forum',
     763              'moduleid  ' => $forum->id,
     764              'userid' => $userid,
     765              'aggregationmethod' => $forum->assessed,
     766              'scaleid' => $forum->scale,
     767              'itemtable' => 'forum_posts',
     768              'itemtableusercolumn' => 'userid',
     769          ]);
     770      }
     771  
     772      $forumgrades = null;
     773      if ($forum->grade_forum) {
     774          $sql = <<<EOF
     775  SELECT
     776      g.userid,
     777      0 as datesubmitted,
     778      g.grade as rawgrade,
     779      g.timemodified as dategraded
     780    FROM {forum} f
     781    JOIN {forum_grades} g ON g.forum = f.id
     782   WHERE f.id = :forumid
     783  EOF;
     784  
     785          $params = [
     786              'forumid' => $forum->id,
     787          ];
     788  
     789          if ($userid) {
     790              $sql .= " AND g.userid = :userid";
     791              $params['userid'] = $userid;
     792          }
     793  
     794          $forumgrades = [];
     795          if ($grades = $DB->get_recordset_sql($sql, $params)) {
     796              foreach ($grades as $userid => $grade) {
     797                  if ($grade->rawgrade != -1) {
     798                      $forumgrades[$userid] = $grade;
     799                  }
     800              }
     801              $grades->close();
     802          }
     803      }
     804  
     805      forum_grade_item_update($forum, $ratings, $forumgrades);
     806  }
     807  
     808  /**
     809   * Create/update grade items for given forum.
     810   *
     811   * @param stdClass $forum Forum object with extra cmidnumber
     812   * @param mixed $grades Optional array/object of grade(s); 'reset' means reset grades in gradebook
     813   */
     814  function forum_grade_item_update($forum, $ratings = null, $forumgrades = null): void {
     815      global $CFG;
     816      require_once("{$CFG->libdir}/gradelib.php");
     817  
     818      // Update the rating.
     819      $item = [
     820          'itemname' => get_string('gradeitemnameforrating', 'forum', $forum),
     821          'idnumber' => $forum->cmidnumber,
     822      ];
     823  
     824      if (!$forum->assessed || $forum->scale == 0) {
     825          $item['gradetype'] = GRADE_TYPE_NONE;
     826      } else if ($forum->scale > 0) {
     827          $item['gradetype'] = GRADE_TYPE_VALUE;
     828          $item['grademax']  = $forum->scale;
     829          $item['grademin']  = 0;
     830      } else if ($forum->scale < 0) {
     831          $item['gradetype'] = GRADE_TYPE_SCALE;
     832          $item['scaleid']   = -$forum->scale;
     833      }
     834  
     835      if ($ratings === 'reset') {
     836          $item['reset'] = true;
     837          $ratings = null;
     838      }
     839      // Itemnumber 0 is the rating.
     840      grade_update('mod/forum', $forum->course, 'mod', 'forum', $forum->id, 0, $ratings, $item);
     841  
     842      // Whole forum grade.
     843      $item = [
     844          'itemname' => get_string('gradeitemnameforwholeforum', 'forum', $forum),
     845          // Note: We do not need to store the idnumber here.
     846      ];
     847  
     848      if (!$forum->grade_forum) {
     849          $item['gradetype'] = GRADE_TYPE_NONE;
     850      } else if ($forum->grade_forum > 0) {
     851          $item['gradetype'] = GRADE_TYPE_VALUE;
     852          $item['grademax'] = $forum->grade_forum;
     853          $item['grademin'] = 0;
     854      } else if ($forum->grade_forum < 0) {
     855          $item['gradetype'] = GRADE_TYPE_SCALE;
     856          $item['scaleid'] = $forum->grade_forum * -1;
     857      }
     858  
     859      if ($forumgrades === 'reset') {
     860          $item['reset'] = true;
     861          $forumgrades = null;
     862      }
     863      // Itemnumber 1 is the whole forum grade.
     864      grade_update('mod/forum', $forum->course, 'mod', 'forum', $forum->id, 1, $forumgrades, $item);
     865  }
     866  
     867  /**
     868   * Delete grade item for given forum.
     869   *
     870   * @param stdClass $forum Forum object
     871   */
     872  function forum_grade_item_delete($forum) {
     873      global $CFG;
     874      require_once($CFG->libdir.'/gradelib.php');
     875  
     876      grade_update('mod/forum', $forum->course, 'mod', 'forum', $forum->id, 0, null, ['deleted' => 1]);
     877      grade_update('mod/forum', $forum->course, 'mod', 'forum', $forum->id, 1, null, ['deleted' => 1]);
     878  }
     879  
     880  /**
     881   * Checks if scale is being used by any instance of forum.
     882   *
     883   * This is used to find out if scale used anywhere.
     884   *
     885   * @param $scaleid int
     886   * @return boolean True if the scale is used by any forum
     887   */
     888  function forum_scale_used_anywhere(int $scaleid): bool {
     889      global $DB;
     890  
     891      if (empty($scaleid)) {
     892          return false;
     893      }
     894  
     895      return $DB->record_exists_select('forum', "scale = ? and assessed > 0", [$scaleid * -1]);
     896  }
     897  
     898  // SQL FUNCTIONS ///////////////////////////////////////////////////////////
     899  
     900  /**
     901   * Gets a post with all info ready for forum_print_post
     902   * Most of these joins are just to get the forum id
     903   *
     904   * @global object
     905   * @global object
     906   * @param int $postid
     907   * @return mixed array of posts or false
     908   */
     909  function forum_get_post_full($postid) {
     910      global $CFG, $DB;
     911  
     912      $userfieldsapi = \core_user\fields::for_name();
     913      $allnames = $userfieldsapi->get_sql('u', false, '', '', false)->selects;
     914      return $DB->get_record_sql("SELECT p.*, d.forum, $allnames, u.email, u.picture, u.imagealt
     915                               FROM {forum_posts} p
     916                                    JOIN {forum_discussions} d ON p.discussion = d.id
     917                                    LEFT JOIN {user} u ON p.userid = u.id
     918                              WHERE p.id = ?", array($postid));
     919  }
     920  
     921  /**
     922   * Gets all posts in discussion including top parent.
     923   *
     924   * @param   int     $discussionid   The Discussion to fetch.
     925   * @param   string  $sort           The sorting to apply.
     926   * @param   bool    $tracking       Whether the user tracks this forum.
     927   * @return  array                   The posts in the discussion.
     928   */
     929  function forum_get_all_discussion_posts($discussionid, $sort, $tracking = false) {
     930      global $CFG, $DB, $USER;
     931  
     932      $tr_sel  = "";
     933      $tr_join = "";
     934      $params = array();
     935  
     936      if ($tracking) {
     937          $tr_sel  = ", fr.id AS postread";
     938          $tr_join = "LEFT JOIN {forum_read} fr ON (fr.postid = p.id AND fr.userid = ?)";
     939          $params[] = $USER->id;
     940      }
     941  
     942      $userfieldsapi = \core_user\fields::for_name();
     943      $allnames = $userfieldsapi->get_sql('u', false, '', '', false)->selects;
     944      $params[] = $discussionid;
     945      if (!$posts = $DB->get_records_sql("SELECT p.*, $allnames, u.email, u.picture, u.imagealt $tr_sel
     946                                       FROM {forum_posts} p
     947                                            LEFT JOIN {user} u ON p.userid = u.id
     948                                            $tr_join
     949                                      WHERE p.discussion = ?
     950                                   ORDER BY $sort", $params)) {
     951          return array();
     952      }
     953  
     954      foreach ($posts as $pid=>$p) {
     955          if ($tracking) {
     956              if (forum_tp_is_post_old($p)) {
     957                   $posts[$pid]->postread = true;
     958              }
     959          }
     960          if (!$p->parent) {
     961              continue;
     962          }
     963          if (!isset($posts[$p->parent])) {
     964              continue; // parent does not exist??
     965          }
     966          if (!isset($posts[$p->parent]->children)) {
     967              $posts[$p->parent]->children = array();
     968          }
     969          $posts[$p->parent]->children[$pid] =& $posts[$pid];
     970      }
     971  
     972      // Start with the last child of the first post.
     973      $post = &$posts[reset($posts)->id];
     974  
     975      $lastpost = false;
     976      while (!$lastpost) {
     977          if (!isset($post->children)) {
     978              $post->lastpost = true;
     979              $lastpost = true;
     980          } else {
     981               // Go to the last child of this post.
     982              $post = &$posts[end($post->children)->id];
     983          }
     984      }
     985  
     986      return $posts;
     987  }
     988  
     989  /**
     990   * An array of forum objects that the user is allowed to read/search through.
     991   *
     992   * @global object
     993   * @global object
     994   * @global object
     995   * @param int $userid
     996   * @param int $courseid if 0, we look for forums throughout the whole site.
     997   * @return array of forum objects, or false if no matches
     998   *         Forum objects have the following attributes:
     999   *         id, type, course, cmid, cmvisible, cmgroupmode, accessallgroups,
    1000   *         viewhiddentimedposts
    1001   */
    1002  function forum_get_readable_forums($userid, $courseid=0) {
    1003  
    1004      global $CFG, $DB, $USER;
    1005      require_once($CFG->dirroot.'/course/lib.php');
    1006  
    1007      if (!$forummod = $DB->get_record('modules', array('name' => 'forum'))) {
    1008          print_error('notinstalled', 'forum');
    1009      }
    1010  
    1011      if ($courseid) {
    1012          $courses = $DB->get_records('course', array('id' => $courseid));
    1013      } else {
    1014          // If no course is specified, then the user can see SITE + his courses.
    1015          $courses1 = $DB->get_records('course', array('id' => SITEID));
    1016          $courses2 = enrol_get_users_courses($userid, true, array('modinfo'));
    1017          $courses = array_merge($courses1, $courses2);
    1018      }
    1019      if (!$courses) {
    1020          return array();
    1021      }
    1022  
    1023      $readableforums = array();
    1024  
    1025      foreach ($courses as $course) {
    1026  
    1027          $modinfo = get_fast_modinfo($course);
    1028  
    1029          if (empty($modinfo->instances['forum'])) {
    1030              // hmm, no forums?
    1031              continue;
    1032          }
    1033  
    1034          $courseforums = $DB->get_records('forum', array('course' => $course->id));
    1035  
    1036          foreach ($modinfo->instances['forum'] as $forumid => $cm) {
    1037              if (!$cm->uservisible or !isset($courseforums[$forumid])) {
    1038                  continue;
    1039              }
    1040              $context = context_module::instance($cm->id);
    1041              $forum = $courseforums[$forumid];
    1042              $forum->context = $context;
    1043              $forum->cm = $cm;
    1044  
    1045              if (!has_capability('mod/forum:viewdiscussion', $context)) {
    1046                  continue;
    1047              }
    1048  
    1049           /// group access
    1050              if (groups_get_activity_groupmode($cm, $course) == SEPARATEGROUPS and !has_capability('moodle/site:accessallgroups', $context)) {
    1051  
    1052                  $forum->onlygroups = $modinfo->get_groups($cm->groupingid);
    1053                  $forum->onlygroups[] = -1;
    1054              }
    1055  
    1056          /// hidden timed discussions
    1057              $forum->viewhiddentimedposts = true;
    1058              if (!empty($CFG->forum_enabletimedposts)) {
    1059                  if (!has_capability('mod/forum:viewhiddentimedposts', $context)) {
    1060                      $forum->viewhiddentimedposts = false;
    1061                  }
    1062              }
    1063  
    1064          /// qanda access
    1065              if ($forum->type == 'qanda'
    1066                      && !has_capability('mod/forum:viewqandawithoutposting', $context)) {
    1067  
    1068                  // We need to check whether the user has posted in the qanda forum.
    1069                  $forum->onlydiscussions = array();  // Holds discussion ids for the discussions
    1070                                                      // the user is allowed to see in this forum.
    1071                  if ($discussionspostedin = forum_discussions_user_has_posted_in($forum->id, $USER->id)) {
    1072                      foreach ($discussionspostedin as $d) {
    1073                          $forum->onlydiscussions[] = $d->id;
    1074                      }
    1075                  }
    1076              }
    1077  
    1078              $readableforums[$forum->id] = $forum;
    1079          }
    1080  
    1081          unset($modinfo);
    1082  
    1083      } // End foreach $courses
    1084  
    1085      return $readableforums;
    1086  }
    1087  
    1088  /**
    1089   * Returns a list of posts found using an array of search terms.
    1090   *
    1091   * @global object
    1092   * @global object
    1093   * @global object
    1094   * @param array $searchterms array of search terms, e.g. word +word -word
    1095   * @param int $courseid if 0, we search through the whole site
    1096   * @param int $limitfrom
    1097   * @param int $limitnum
    1098   * @param int &$totalcount
    1099   * @param string $extrasql
    1100   * @return array|bool Array of posts found or false
    1101   */
    1102  function forum_search_posts($searchterms, $courseid, $limitfrom, $limitnum,
    1103                              &$totalcount, $extrasql='') {
    1104      global $CFG, $DB, $USER;
    1105      require_once($CFG->libdir.'/searchlib.php');
    1106  
    1107      $forums = forum_get_readable_forums($USER->id, $courseid);
    1108  
    1109      if (count($forums) == 0) {
    1110          $totalcount = 0;
    1111          return false;
    1112      }
    1113  
    1114      $now = floor(time() / 60) * 60; // DB Cache Friendly.
    1115  
    1116      $fullaccess = array();
    1117      $where = array();
    1118      $params = array();
    1119  
    1120      foreach ($forums as $forumid => $forum) {
    1121          $select = array();
    1122  
    1123          if (!$forum->viewhiddentimedposts) {
    1124              $select[] = "(d.userid = :userid{$forumid} OR (d.timestart < :timestart{$forumid} AND (d.timeend = 0 OR d.timeend > :timeend{$forumid})))";
    1125              $params = array_merge($params, array('userid'.$forumid=>$USER->id, 'timestart'.$forumid=>$now, 'timeend'.$forumid=>$now));
    1126          }
    1127  
    1128          $cm = $forum->cm;
    1129          $context = $forum->context;
    1130  
    1131          if ($forum->type == 'qanda'
    1132              && !has_capability('mod/forum:viewqandawithoutposting', $context)) {
    1133              if (!empty($forum->onlydiscussions)) {
    1134                  list($discussionid_sql, $discussionid_params) = $DB->get_in_or_equal($forum->onlydiscussions, SQL_PARAMS_NAMED, 'qanda'.$forumid.'_');
    1135                  $params = array_merge($params, $discussionid_params);
    1136                  $select[] = "(d.id $discussionid_sql OR p.parent = 0)";
    1137              } else {
    1138                  $select[] = "p.parent = 0";
    1139              }
    1140          }
    1141  
    1142          if (!empty($forum->onlygroups)) {
    1143              list($groupid_sql, $groupid_params) = $DB->get_in_or_equal($forum->onlygroups, SQL_PARAMS_NAMED, 'grps'.$forumid.'_');
    1144              $params = array_merge($params, $groupid_params);
    1145              $select[] = "d.groupid $groupid_sql";
    1146          }
    1147  
    1148          if ($select) {
    1149              $selects = implode(" AND ", $select);
    1150              $where[] = "(d.forum = :forum{$forumid} AND $selects)";
    1151              $params['forum'.$forumid] = $forumid;
    1152          } else {
    1153              $fullaccess[] = $forumid;
    1154          }
    1155      }
    1156  
    1157      if ($fullaccess) {
    1158          list($fullid_sql, $fullid_params) = $DB->get_in_or_equal($fullaccess, SQL_PARAMS_NAMED, 'fula');
    1159          $params = array_merge($params, $fullid_params);
    1160          $where[] = "(d.forum $fullid_sql)";
    1161      }
    1162  
    1163      $favjoin = "";
    1164      if (in_array('starredonly:on', $searchterms)) {
    1165          $usercontext = context_user::instance($USER->id);
    1166          $ufservice = \core_favourites\service_factory::get_service_for_user_context($usercontext);
    1167          list($favjoin, $favparams) = $ufservice->get_join_sql_by_type('mod_forum', 'discussions',
    1168              "favourited", "d.id");
    1169  
    1170          $searchterms = array_values(array_diff($searchterms, array('starredonly:on')));
    1171          $params = array_merge($params, $favparams);
    1172          $extrasql .= " AND favourited.itemid IS NOT NULL AND favourited.itemid != 0";
    1173      }
    1174  
    1175      $selectdiscussion = "(".implode(" OR ", $where).")";
    1176  
    1177      $messagesearch = '';
    1178      $searchstring = '';
    1179  
    1180      // Need to concat these back together for parser to work.
    1181      foreach($searchterms as $searchterm){
    1182          if ($searchstring != '') {
    1183              $searchstring .= ' ';
    1184          }
    1185          $searchstring .= $searchterm;
    1186      }
    1187  
    1188      // We need to allow quoted strings for the search. The quotes *should* be stripped
    1189      // by the parser, but this should be examined carefully for security implications.
    1190      $searchstring = str_replace("\\\"","\"",$searchstring);
    1191      $parser = new search_parser();
    1192      $lexer = new search_lexer($parser);
    1193  
    1194      if ($lexer->parse($searchstring)) {
    1195          $parsearray = $parser->get_parsed_array();
    1196  
    1197          $tagjoins = '';
    1198          $tagfields = [];
    1199          $tagfieldcount = 0;
    1200          if ($parsearray) {
    1201              foreach ($parsearray as $token) {
    1202                  if ($token->getType() == TOKEN_TAGS) {
    1203                      for ($i = 0; $i <= substr_count($token->getValue(), ','); $i++) {
    1204                          // Queries can only have a limited number of joins so set a limit sensible users won't exceed.
    1205                          if ($tagfieldcount > 10) {
    1206                              continue;
    1207                          }
    1208                          $tagjoins .= " LEFT JOIN {tag_instance} ti_$tagfieldcount
    1209                                          ON p.id = ti_$tagfieldcount.itemid
    1210                                              AND ti_$tagfieldcount.component = 'mod_forum'
    1211                                              AND ti_$tagfieldcount.itemtype = 'forum_posts'";
    1212                          $tagjoins .= " LEFT JOIN {tag} t_$tagfieldcount ON t_$tagfieldcount.id = ti_$tagfieldcount.tagid";
    1213                          $tagfields[] = "t_$tagfieldcount.rawname";
    1214                          $tagfieldcount++;
    1215                      }
    1216                  }
    1217              }
    1218              list($messagesearch, $msparams) = search_generate_SQL($parsearray, 'p.message', 'p.subject',
    1219                  'p.userid', 'u.id', 'u.firstname',
    1220                  'u.lastname', 'p.modified', 'd.forum',
    1221                  $tagfields);
    1222  
    1223              $params = ($msparams ? array_merge($params, $msparams) : $params);
    1224          }
    1225      }
    1226  
    1227      $fromsql = "{forum_posts} p
    1228                    INNER JOIN {forum_discussions} d ON d.id = p.discussion
    1229                    INNER JOIN {user} u ON u.id = p.userid $tagjoins $favjoin";
    1230  
    1231      $selectsql = ($messagesearch ? $messagesearch . " AND " : "").
    1232                  " p.discussion = d.id
    1233                 AND p.userid = u.id
    1234                 AND $selectdiscussion
    1235                     $extrasql";
    1236  
    1237      $countsql = "SELECT COUNT(*)
    1238                     FROM $fromsql
    1239                    WHERE $selectsql";
    1240  
    1241      $userfieldsapi = \core_user\fields::for_name();
    1242      $allnames = $userfieldsapi->get_sql('u', false, '', '', false)->selects;
    1243      $searchsql = "SELECT p.*,
    1244                           d.forum,
    1245                           $allnames,
    1246                           u.email,
    1247                           u.picture,
    1248                           u.imagealt
    1249                      FROM $fromsql
    1250                     WHERE $selectsql
    1251                  ORDER BY p.modified DESC";
    1252  
    1253      $totalcount = $DB->count_records_sql($countsql, $params);
    1254  
    1255      return $DB->get_records_sql($searchsql, $params, $limitfrom, $limitnum);
    1256  }
    1257  
    1258  /**
    1259   * Get all the posts for a user in a forum suitable for forum_print_post
    1260   *
    1261   * @global object
    1262   * @global object
    1263   * @uses CONTEXT_MODULE
    1264   * @return array
    1265   */
    1266  function forum_get_user_posts($forumid, $userid) {
    1267      global $CFG, $DB;
    1268  
    1269      $timedsql = "";
    1270      $params = array($forumid, $userid);
    1271  
    1272      if (!empty($CFG->forum_enabletimedposts)) {
    1273          $cm = get_coursemodule_from_instance('forum', $forumid);
    1274          if (!has_capability('mod/forum:viewhiddentimedposts' , context_module::instance($cm->id))) {
    1275              $now = time();
    1276              $timedsql = "AND (d.timestart < ? AND (d.timeend = 0 OR d.timeend > ?))";
    1277              $params[] = $now;
    1278              $params[] = $now;
    1279          }
    1280      }
    1281  
    1282      $userfieldsapi = \core_user\fields::for_name();
    1283      $allnames = $userfieldsapi->get_sql('u', false, '', '', false)->selects;
    1284      return $DB->get_records_sql("SELECT p.*, d.forum, $allnames, u.email, u.picture, u.imagealt
    1285                                FROM {forum} f
    1286                                     JOIN {forum_discussions} d ON d.forum = f.id
    1287                                     JOIN {forum_posts} p       ON p.discussion = d.id
    1288                                     JOIN {user} u              ON u.id = p.userid
    1289                               WHERE f.id = ?
    1290                                     AND p.userid = ?
    1291                                     $timedsql
    1292                            ORDER BY p.modified ASC", $params);
    1293  }
    1294  
    1295  /**
    1296   * Get all the discussions user participated in
    1297   *
    1298   * @global object
    1299   * @global object
    1300   * @uses CONTEXT_MODULE
    1301   * @param int $forumid
    1302   * @param int $userid
    1303   * @return array Array or false
    1304   */
    1305  function forum_get_user_involved_discussions($forumid, $userid) {
    1306      global $CFG, $DB;
    1307  
    1308      $timedsql = "";
    1309      $params = array($forumid, $userid);
    1310      if (!empty($CFG->forum_enabletimedposts)) {
    1311          $cm = get_coursemodule_from_instance('forum', $forumid);
    1312          if (!has_capability('mod/forum:viewhiddentimedposts' , context_module::instance($cm->id))) {
    1313              $now = time();
    1314              $timedsql = "AND (d.timestart < ? AND (d.timeend = 0 OR d.timeend > ?))";
    1315              $params[] = $now;
    1316              $params[] = $now;
    1317          }
    1318      }
    1319  
    1320      return $DB->get_records_sql("SELECT DISTINCT d.*
    1321                                FROM {forum} f
    1322                                     JOIN {forum_discussions} d ON d.forum = f.id
    1323                                     JOIN {forum_posts} p       ON p.discussion = d.id
    1324                               WHERE f.id = ?
    1325                                     AND p.userid = ?
    1326                                     $timedsql", $params);
    1327  }
    1328  
    1329  /**
    1330   * Get all the posts for a user in a forum suitable for forum_print_post
    1331   *
    1332   * @global object
    1333   * @global object
    1334   * @param int $forumid
    1335   * @param int $userid
    1336   * @return array of counts or false
    1337   */
    1338  function forum_count_user_posts($forumid, $userid) {
    1339      global $CFG, $DB;
    1340  
    1341      $timedsql = "";
    1342      $params = array($forumid, $userid);
    1343      if (!empty($CFG->forum_enabletimedposts)) {
    1344          $cm = get_coursemodule_from_instance('forum', $forumid);
    1345          if (!has_capability('mod/forum:viewhiddentimedposts' , context_module::instance($cm->id))) {
    1346              $now = time();
    1347              $timedsql = "AND (d.timestart < ? AND (d.timeend = 0 OR d.timeend > ?))";
    1348              $params[] = $now;
    1349              $params[] = $now;
    1350          }
    1351      }
    1352  
    1353      return $DB->get_record_sql("SELECT COUNT(p.id) AS postcount, MAX(p.modified) AS lastpost
    1354                               FROM {forum} f
    1355                                    JOIN {forum_discussions} d ON d.forum = f.id
    1356                                    JOIN {forum_posts} p       ON p.discussion = d.id
    1357                                    JOIN {user} u              ON u.id = p.userid
    1358                              WHERE f.id = ?
    1359                                    AND p.userid = ?
    1360                                    $timedsql", $params);
    1361  }
    1362  
    1363  /**
    1364   * Given a log entry, return the forum post details for it.
    1365   *
    1366   * @global object
    1367   * @global object
    1368   * @param object $log
    1369   * @return array|null
    1370   */
    1371  function forum_get_post_from_log($log) {
    1372      global $CFG, $DB;
    1373  
    1374      $userfieldsapi = \core_user\fields::for_name();
    1375      $allnames = $userfieldsapi->get_sql('u', false, '', '', false)->selects;
    1376      if ($log->action == "add post") {
    1377  
    1378          return $DB->get_record_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid, $allnames, u.email, u.picture
    1379                                   FROM {forum_discussions} d,
    1380                                        {forum_posts} p,
    1381                                        {forum} f,
    1382                                        {user} u
    1383                                  WHERE p.id = ?
    1384                                    AND d.id = p.discussion
    1385                                    AND p.userid = u.id
    1386                                    AND u.deleted <> '1'
    1387                                    AND f.id = d.forum", array($log->info));
    1388  
    1389  
    1390      } else if ($log->action == "add discussion") {
    1391  
    1392          return $DB->get_record_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid, $allnames, u.email, u.picture
    1393                                   FROM {forum_discussions} d,
    1394                                        {forum_posts} p,
    1395                                        {forum} f,
    1396                                        {user} u
    1397                                  WHERE d.id = ?
    1398                                    AND d.firstpost = p.id
    1399                                    AND p.userid = u.id
    1400                                    AND u.deleted <> '1'
    1401                                    AND f.id = d.forum", array($log->info));
    1402      }
    1403      return NULL;
    1404  }
    1405  
    1406  /**
    1407   * Given a discussion id, return the first post from the discussion
    1408   *
    1409   * @global object
    1410   * @global object
    1411   * @param int $dicsussionid
    1412   * @return array
    1413   */
    1414  function forum_get_firstpost_from_discussion($discussionid) {
    1415      global $CFG, $DB;
    1416  
    1417      return $DB->get_record_sql("SELECT p.*
    1418                               FROM {forum_discussions} d,
    1419                                    {forum_posts} p
    1420                              WHERE d.id = ?
    1421                                AND d.firstpost = p.id ", array($discussionid));
    1422  }
    1423  
    1424  /**
    1425   * Returns an array of counts of replies to each discussion
    1426   *
    1427   * @param   int     $forumid
    1428   * @param   string  $forumsort
    1429   * @param   int     $limit
    1430   * @param   int     $page
    1431   * @param   int     $perpage
    1432   * @param   boolean $canseeprivatereplies   Whether the current user can see private replies.
    1433   * @return  array
    1434   */
    1435  function forum_count_discussion_replies($forumid, $forumsort = "", $limit = -1, $page = -1, $perpage = 0,
    1436                                          $canseeprivatereplies = false) {
    1437      global $CFG, $DB, $USER;
    1438  
    1439      if ($limit > 0) {
    1440          $limitfrom = 0;
    1441          $limitnum  = $limit;
    1442      } else if ($page != -1) {
    1443          $limitfrom = $page*$perpage;
    1444          $limitnum  = $perpage;
    1445      } else {
    1446          $limitfrom = 0;
    1447          $limitnum  = 0;
    1448      }
    1449  
    1450      if ($forumsort == "") {
    1451          $orderby = "";
    1452          $groupby = "";
    1453  
    1454      } else {
    1455          $orderby = "ORDER BY $forumsort";
    1456          $groupby = ", ".strtolower($forumsort);
    1457          $groupby = str_replace('desc', '', $groupby);
    1458          $groupby = str_replace('asc', '', $groupby);
    1459      }
    1460  
    1461      $params = ['forumid' => $forumid];
    1462  
    1463      if (!$canseeprivatereplies) {
    1464          $privatewhere = ' AND (p.privatereplyto = :currentuser1 OR p.userid = :currentuser2 OR p.privatereplyto = 0)';
    1465          $params['currentuser1'] = $USER->id;
    1466          $params['currentuser2'] = $USER->id;
    1467      } else {
    1468          $privatewhere = '';
    1469      }
    1470  
    1471      if (($limitfrom == 0 and $limitnum == 0) or $forumsort == "") {
    1472          $sql = "SELECT p.discussion, COUNT(p.id) AS replies, MAX(p.id) AS lastpostid
    1473                    FROM {forum_posts} p
    1474                         JOIN {forum_discussions} d ON p.discussion = d.id
    1475                   WHERE p.parent > 0 AND d.forum = :forumid
    1476                         $privatewhere
    1477                GROUP BY p.discussion";
    1478          return $DB->get_records_sql($sql, $params);
    1479  
    1480      } else {
    1481          $sql = "SELECT p.discussion, (COUNT(p.id) - 1) AS replies, MAX(p.id) AS lastpostid
    1482                    FROM {forum_posts} p
    1483                         JOIN {forum_discussions} d ON p.discussion = d.id
    1484                   WHERE d.forum = :forumid
    1485                         $privatewhere
    1486                GROUP BY p.discussion $groupby $orderby";
    1487          return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
    1488      }
    1489  }
    1490  
    1491  /**
    1492   * @global object
    1493   * @global object
    1494   * @global object
    1495   * @staticvar array $cache
    1496   * @param object $forum
    1497   * @param object $cm
    1498   * @param object $course
    1499   * @return mixed
    1500   */
    1501  function forum_count_discussions($forum, $cm, $course) {
    1502      global $CFG, $DB, $USER;
    1503  
    1504      static $cache = array();
    1505  
    1506      $now = floor(time() / 60) * 60; // DB Cache Friendly.
    1507  
    1508      $params = array($course->id);
    1509  
    1510      if (!isset($cache[$course->id])) {
    1511          if (!empty($CFG->forum_enabletimedposts)) {
    1512              $timedsql = "AND d.timestart < ? AND (d.timeend = 0 OR d.timeend > ?)";
    1513              $params[] = $now;
    1514              $params[] = $now;
    1515          } else {
    1516              $timedsql = "";
    1517          }
    1518  
    1519          $sql = "SELECT f.id, COUNT(d.id) as dcount
    1520                    FROM {forum} f
    1521                         JOIN {forum_discussions} d ON d.forum = f.id
    1522                   WHERE f.course = ?
    1523                         $timedsql
    1524                GROUP BY f.id";
    1525  
    1526          if ($counts = $DB->get_records_sql($sql, $params)) {
    1527              foreach ($counts as $count) {
    1528                  $counts[$count->id] = $count->dcount;
    1529              }
    1530              $cache[$course->id] = $counts;
    1531          } else {
    1532              $cache[$course->id] = array();
    1533          }
    1534      }
    1535  
    1536      if (empty($cache[$course->id][$forum->id])) {
    1537          return 0;
    1538      }
    1539  
    1540      $groupmode = groups_get_activity_groupmode($cm, $course);
    1541  
    1542      if ($groupmode != SEPARATEGROUPS) {
    1543          return $cache[$course->id][$forum->id];
    1544      }
    1545  
    1546      if (has_capability('moodle/site:accessallgroups', context_module::instance($cm->id))) {
    1547          return $cache[$course->id][$forum->id];
    1548      }
    1549  
    1550      require_once($CFG->dirroot.'/course/lib.php');
    1551  
    1552      $modinfo = get_fast_modinfo($course);
    1553  
    1554      $mygroups = $modinfo->get_groups($cm->groupingid);
    1555  
    1556      // add all groups posts
    1557      $mygroups[-1] = -1;
    1558  
    1559      list($mygroups_sql, $params) = $DB->get_in_or_equal($mygroups);
    1560      $params[] = $forum->id;
    1561  
    1562      if (!empty($CFG->forum_enabletimedposts)) {
    1563          $timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";
    1564          $params[] = $now;
    1565          $params[] = $now;
    1566      } else {
    1567          $timedsql = "";
    1568      }
    1569  
    1570      $sql = "SELECT COUNT(d.id)
    1571                FROM {forum_discussions} d
    1572               WHERE d.groupid $mygroups_sql AND d.forum = ?
    1573                     $timedsql";
    1574  
    1575      return $DB->get_field_sql($sql, $params);
    1576  }
    1577  
    1578  /**
    1579   * Get all discussions in a forum
    1580   *
    1581   * @global object
    1582   * @global object
    1583   * @global object
    1584   * @uses CONTEXT_MODULE
    1585   * @uses VISIBLEGROUPS
    1586   * @param object $cm
    1587   * @param string $forumsort
    1588   * @param bool $fullpost
    1589   * @param int $unused
    1590   * @param int $limit
    1591   * @param bool $userlastmodified
    1592   * @param int $page
    1593   * @param int $perpage
    1594   * @param int $groupid if groups enabled, get discussions for this group overriding the current group.
    1595   *                     Use FORUM_POSTS_ALL_USER_GROUPS for all the user groups
    1596   * @param int $updatedsince retrieve only discussions updated since the given time
    1597   * @return array
    1598   */
    1599  function forum_get_discussions($cm, $forumsort="", $fullpost=true, $unused=-1, $limit=-1,
    1600                                  $userlastmodified=false, $page=-1, $perpage=0, $groupid = -1,
    1601                                  $updatedsince = 0) {
    1602      global $CFG, $DB, $USER;
    1603  
    1604      $timelimit = '';
    1605  
    1606      $now = floor(time() / 60) * 60;
    1607      $params = array($cm->instance);
    1608  
    1609      $modcontext = context_module::instance($cm->id);
    1610  
    1611      if (!has_capability('mod/forum:viewdiscussion', $modcontext)) { /// User must have perms to view discussions
    1612          return array();
    1613      }
    1614  
    1615      if (!empty($CFG->forum_enabletimedposts)) { /// Users must fulfill timed posts
    1616  
    1617          if (!has_capability('mod/forum:viewhiddentimedposts', $modcontext)) {
    1618              $timelimit = " AND ((d.timestart <= ? AND (d.timeend = 0 OR d.timeend > ?))";
    1619              $params[] = $now;
    1620              $params[] = $now;
    1621              if (isloggedin()) {
    1622                  $timelimit .= " OR d.userid = ?";
    1623                  $params[] = $USER->id;
    1624              }
    1625              $timelimit .= ")";
    1626          }
    1627      }
    1628  
    1629      if ($limit > 0) {
    1630          $limitfrom = 0;
    1631          $limitnum  = $limit;
    1632      } else if ($page != -1) {
    1633          $limitfrom = $page*$perpage;
    1634          $limitnum  = $perpage;
    1635      } else {
    1636          $limitfrom = 0;
    1637          $limitnum  = 0;
    1638      }
    1639  
    1640      $groupmode    = groups_get_activity_groupmode($cm);
    1641  
    1642      if ($groupmode) {
    1643  
    1644          if (empty($modcontext)) {
    1645              $modcontext = context_module::instance($cm->id);
    1646          }
    1647  
    1648          // Special case, we received a groupid to override currentgroup.
    1649          if ($groupid > 0) {
    1650              $course = get_course($cm->course);
    1651              if (!groups_group_visible($groupid, $course, $cm)) {
    1652                  // User doesn't belong to this group, return nothing.
    1653                  return array();
    1654              }
    1655              $currentgroup = $groupid;
    1656          } else if ($groupid === -1) {
    1657              $currentgroup = groups_get_activity_group($cm);
    1658          } else {
    1659              // Get discussions for all groups current user can see.
    1660              $currentgroup = null;
    1661          }
    1662  
    1663          if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {
    1664              if ($currentgroup) {
    1665                  $groupselect = "AND (d.groupid = ? OR d.groupid = -1)";
    1666                  $params[] = $currentgroup;
    1667              } else {
    1668                  $groupselect = "";
    1669              }
    1670  
    1671          } else {
    1672              // Separate groups.
    1673  
    1674              // Get discussions for all groups current user can see.
    1675              if ($currentgroup === null) {
    1676                  $mygroups = array_keys(groups_get_all_groups($cm->course, $USER->id, $cm->groupingid, 'g.id'));
    1677                  if (empty($mygroups)) {
    1678                       $groupselect = "AND d.groupid = -1";
    1679                  } else {
    1680                      list($insqlgroups, $inparamsgroups) = $DB->get_in_or_equal($mygroups);
    1681                      $groupselect = "AND (d.groupid = -1 OR d.groupid $insqlgroups)";
    1682                      $params = array_merge($params, $inparamsgroups);
    1683                  }
    1684              } else if ($currentgroup) {
    1685                  $groupselect = "AND (d.groupid = ? OR d.groupid = -1)";
    1686                  $params[] = $currentgroup;
    1687              } else {
    1688                  $groupselect = "AND d.groupid = -1";
    1689              }
    1690          }
    1691      } else {
    1692          $groupselect = "";
    1693      }
    1694      if (empty($forumsort)) {
    1695          $forumsort = forum_get_default_sort_order();
    1696      }
    1697      if (empty($fullpost)) {
    1698          $postdata = "p.id, p.subject, p.modified, p.discussion, p.userid, p.created";
    1699      } else {
    1700          $postdata = "p.*";
    1701      }
    1702  
    1703      $userfieldsapi = \core_user\fields::for_name();
    1704  
    1705      if (empty($userlastmodified)) {  // We don't need to know this
    1706          $umfields = "";
    1707          $umtable  = "";
    1708      } else {
    1709          $umfields = $userfieldsapi->get_sql('um', false, 'um')->selects . ', um.email AS umemail, um.picture AS umpicture,
    1710                          um.imagealt AS umimagealt';
    1711          $umtable  = " LEFT JOIN {user} um ON (d.usermodified = um.id)";
    1712      }
    1713  
    1714      $updatedsincesql = '';
    1715      if (!empty($updatedsince)) {
    1716          $updatedsincesql = 'AND d.timemodified > ?';
    1717          $params[] = $updatedsince;
    1718      }
    1719  
    1720      $discussionfields = "d.id as discussionid, d.course, d.forum, d.name, d.firstpost, d.groupid, d.assessed," .
    1721      " d.timemodified, d.usermodified, d.timestart, d.timeend, d.pinned, d.timelocked";
    1722  
    1723      $allnames = $userfieldsapi->get_sql('u', false, '', '', false)->selects;
    1724      $sql = "SELECT $postdata, $discussionfields,
    1725                     $allnames, u.email, u.picture, u.imagealt $umfields
    1726                FROM {forum_discussions} d
    1727                     JOIN {forum_posts} p ON p.discussion = d.id
    1728                     JOIN {user} u ON p.userid = u.id
    1729                     $umtable
    1730               WHERE d.forum = ? AND p.parent = 0
    1731                     $timelimit $groupselect $updatedsincesql
    1732            ORDER BY $forumsort, d.id DESC";
    1733  
    1734      return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
    1735  }
    1736  
    1737  /**
    1738   * Gets the neighbours (previous and next) of a discussion.
    1739   *
    1740   * The calculation is based on the timemodified when time modified or time created is identical
    1741   * It will revert to using the ID to sort consistently. This is better tha skipping a discussion.
    1742   *
    1743   * For blog-style forums, the calculation is based on the original creation time of the
    1744   * blog post.
    1745   *
    1746   * Please note that this does not check whether or not the discussion passed is accessible
    1747   * by the user, it simply uses it as a reference to find the neighbours. On the other hand,
    1748   * the returned neighbours are checked and are accessible to the current user.
    1749   *
    1750   * @param object $cm The CM record.
    1751   * @param object $discussion The discussion record.
    1752   * @param object $forum The forum instance record.
    1753   * @return array That always contains the keys 'prev' and 'next'. When there is a result
    1754   *               they contain the record with minimal information such as 'id' and 'name'.
    1755   *               When the neighbour is not found the value is false.
    1756   */
    1757  function forum_get_discussion_neighbours($cm, $discussion, $forum) {
    1758      global $CFG, $DB, $USER;
    1759  
    1760      if ($cm->instance != $discussion->forum or $discussion->forum != $forum->id or $forum->id != $cm->instance) {
    1761          throw new coding_exception('Discussion is not part of the same forum.');
    1762      }
    1763  
    1764      $neighbours = array('prev' => false, 'next' => false);
    1765      $now = floor(time() / 60) * 60;
    1766      $params = array();
    1767  
    1768      $modcontext = context_module::instance($cm->id);
    1769      $groupmode    = groups_get_activity_groupmode($cm);
    1770      $currentgroup = groups_get_activity_group($cm);
    1771  
    1772      // Users must fulfill timed posts.
    1773      $timelimit = '';
    1774      if (!empty($CFG->forum_enabletimedposts)) {
    1775          if (!has_capability('mod/forum:viewhiddentimedposts', $modcontext)) {
    1776              $timelimit = ' AND ((d.timestart <= :tltimestart AND (d.timeend = 0 OR d.timeend > :tltimeend))';
    1777              $params['tltimestart'] = $now;
    1778              $params['tltimeend'] = $now;
    1779              if (isloggedin()) {
    1780                  $timelimit .= ' OR d.userid = :tluserid';
    1781                  $params['tluserid'] = $USER->id;
    1782              }
    1783              $timelimit .= ')';
    1784          }
    1785      }
    1786  
    1787      // Limiting to posts accessible according to groups.
    1788      $groupselect = '';
    1789      if ($groupmode) {
    1790          if ($groupmode == VISIBLEGROUPS || has_capability('moodle/site:accessallgroups', $modcontext)) {
    1791              if ($currentgroup) {
    1792                  $groupselect = 'AND (d.groupid = :groupid OR d.groupid = -1)';
    1793                  $params['groupid'] = $currentgroup;
    1794              }
    1795          } else {
    1796              if ($currentgroup) {
    1797                  $groupselect = 'AND (d.groupid = :groupid OR d.groupid = -1)';
    1798                  $params['groupid'] = $currentgroup;
    1799              } else {
    1800                  $groupselect = 'AND d.groupid = -1';
    1801              }
    1802          }
    1803      }
    1804  
    1805      $params['forumid'] = $cm->instance;
    1806      $params['discid1'] = $discussion->id;
    1807      $params['discid2'] = $discussion->id;
    1808      $params['discid3'] = $discussion->id;
    1809      $params['discid4'] = $discussion->id;
    1810      $params['disctimecompare1'] = $discussion->timemodified;
    1811      $params['disctimecompare2'] = $discussion->timemodified;
    1812      $params['pinnedstate1'] = (int) $discussion->pinned;
    1813      $params['pinnedstate2'] = (int) $discussion->pinned;
    1814      $params['pinnedstate3'] = (int) $discussion->pinned;
    1815      $params['pinnedstate4'] = (int) $discussion->pinned;
    1816  
    1817      $sql = "SELECT d.id, d.name, d.timemodified, d.groupid, d.timestart, d.timeend
    1818                FROM {forum_discussions} d
    1819                JOIN {forum_posts} p ON d.firstpost = p.id
    1820               WHERE d.forum = :forumid
    1821                 AND d.id <> :discid1
    1822                     $timelimit
    1823                     $groupselect";
    1824      $comparefield = "d.timemodified";
    1825      $comparevalue = ":disctimecompare1";
    1826      $comparevalue2  = ":disctimecompare2";
    1827      if (!empty($CFG->forum_enabletimedposts)) {
    1828          // Here we need to take into account the release time (timestart)
    1829          // if one is set, of the neighbouring posts and compare it to the
    1830          // timestart or timemodified of *this* post depending on if the
    1831          // release date of this post is in the future or not.
    1832          // This stops discussions that appear later because of the
    1833          // timestart value from being buried under discussions that were
    1834          // made afterwards.
    1835          $comparefield = "CASE WHEN d.timemodified < d.timestart
    1836                                  THEN d.timestart ELSE d.timemodified END";
    1837          if ($discussion->timemodified < $discussion->timestart) {
    1838              // Normally we would just use the timemodified for sorting
    1839              // discussion posts. However, when timed discussions are enabled,
    1840              // then posts need to be sorted base on the later of timemodified
    1841              // or the release date of the post (timestart).
    1842              $params['disctimecompare1'] = $discussion->timestart;
    1843              $params['disctimecompare2'] = $discussion->timestart;
    1844          }
    1845      }
    1846      $orderbydesc = forum_get_default_sort_order(true, $comparefield, 'd', false);
    1847      $orderbyasc = forum_get_default_sort_order(false, $comparefield, 'd', false);
    1848  
    1849      if ($forum->type === 'blog') {
    1850           $subselect = "SELECT pp.created
    1851                     FROM {forum_discussions} dd
    1852                     JOIN {forum_posts} pp ON dd.firstpost = pp.id ";
    1853  
    1854           $subselectwhere1 = " WHERE dd.id = :discid3";
    1855           $subselectwhere2 = " WHERE dd.id = :discid4";
    1856  
    1857           $comparefield = "p.created";
    1858  
    1859           $sub1 = $subselect.$subselectwhere1;
    1860           $comparevalue = "($sub1)";
    1861  
    1862           $sub2 = $subselect.$subselectwhere2;
    1863           $comparevalue2 = "($sub2)";
    1864  
    1865           $orderbydesc = "d.pinned, p.created DESC";
    1866           $orderbyasc = "d.pinned, p.created ASC";
    1867      }
    1868  
    1869      $prevsql = $sql . " AND ( (($comparefield < $comparevalue) AND :pinnedstate1 = d.pinned)
    1870                           OR ($comparefield = $comparevalue2 AND (d.pinned = 0 OR d.pinned = :pinnedstate4) AND d.id < :discid2)
    1871                           OR (d.pinned = 0 AND d.pinned <> :pinnedstate2))
    1872                     ORDER BY CASE WHEN d.pinned = :pinnedstate3 THEN 1 ELSE 0 END DESC, $orderbydesc, d.id DESC";
    1873  
    1874      $nextsql = $sql . " AND ( (($comparefield > $comparevalue) AND :pinnedstate1 = d.pinned)
    1875                           OR ($comparefield = $comparevalue2 AND (d.pinned = 1 OR d.pinned = :pinnedstate4) AND d.id > :discid2)
    1876                           OR (d.pinned = 1 AND d.pinned <> :pinnedstate2))
    1877                     ORDER BY CASE WHEN d.pinned = :pinnedstate3 THEN 1 ELSE 0 END DESC, $orderbyasc, d.id ASC";
    1878  
    1879      $neighbours['prev'] = $DB->get_record_sql($prevsql, $params, IGNORE_MULTIPLE);
    1880      $neighbours['next'] = $DB->get_record_sql($nextsql, $params, IGNORE_MULTIPLE);
    1881      return $neighbours;
    1882  }
    1883  
    1884  /**
    1885   * Get the sql to use in the ORDER BY clause for forum discussions.
    1886   *
    1887   * This has the ordering take timed discussion windows into account.
    1888   *
    1889   * @param bool $desc True for DESC, False for ASC.
    1890   * @param string $compare The field in the SQL to compare to normally sort by.
    1891   * @param string $prefix The prefix being used for the discussion table.
    1892   * @param bool $pinned sort pinned posts to the top
    1893   * @return string
    1894   */
    1895  function forum_get_default_sort_order($desc = true, $compare = 'd.timemodified', $prefix = 'd', $pinned = true) {
    1896      global $CFG;
    1897  
    1898      if (!empty($prefix)) {
    1899          $prefix .= '.';
    1900      }
    1901  
    1902      $dir = $desc ? 'DESC' : 'ASC';
    1903  
    1904      if ($pinned == true) {
    1905          $pinned = "{$prefix}pinned DESC,";
    1906      } else {
    1907          $pinned = '';
    1908      }
    1909  
    1910      $sort = "{$prefix}timemodified";
    1911      if (!empty($CFG->forum_enabletimedposts)) {
    1912          $sort = "CASE WHEN {$compare} < {$prefix}timestart
    1913                   THEN {$prefix}timestart
    1914                   ELSE {$compare}
    1915                   END";
    1916      }
    1917      return "$pinned $sort $dir";
    1918  }
    1919  
    1920  /**
    1921   *
    1922   * @global object
    1923   * @global object
    1924   * @global object
    1925   * @uses CONTEXT_MODULE
    1926   * @uses VISIBLEGROUPS
    1927   * @param object $cm
    1928   * @return array
    1929   */
    1930  function forum_get_discussions_unread($cm) {
    1931      global $CFG, $DB, $USER;
    1932  
    1933      $now = floor(time() / 60) * 60;
    1934      $cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);
    1935  
    1936      $params = array();
    1937      $groupmode    = groups_get_activity_groupmode($cm);
    1938      $currentgroup = groups_get_activity_group($cm);
    1939  
    1940      if ($groupmode) {
    1941          $modcontext = context_module::instance($cm->id);
    1942  
    1943          if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {
    1944              if ($currentgroup) {
    1945                  $groupselect = "AND (d.groupid = :currentgroup OR d.groupid = -1)";
    1946                  $params['currentgroup'] = $currentgroup;
    1947              } else {
    1948                  $groupselect = "";
    1949              }
    1950  
    1951          } else {
    1952              //separate groups without access all
    1953              if ($currentgroup) {
    1954                  $groupselect = "AND (d.groupid = :currentgroup OR d.groupid = -1)";
    1955                  $params['currentgroup'] = $currentgroup;
    1956              } else {
    1957                  $groupselect = "AND d.groupid = -1";
    1958              }
    1959          }
    1960      } else {
    1961          $groupselect = "";
    1962      }
    1963  
    1964      if (!empty($CFG->forum_enabletimedposts)) {
    1965          $timedsql = "AND d.timestart < :now1 AND (d.timeend = 0 OR d.timeend > :now2)";
    1966          $params['now1'] = $now;
    1967          $params['now2'] = $now;
    1968      } else {
    1969          $timedsql = "";
    1970      }
    1971  
    1972      $sql = "SELECT d.id, COUNT(p.id) AS unread
    1973                FROM {forum_discussions} d
    1974                     JOIN {forum_posts} p     ON p.discussion = d.id
    1975                     LEFT JOIN {forum_read} r ON (r.postid = p.id AND r.userid = $USER->id)
    1976               WHERE d.forum = {$cm->instance}
    1977                     AND p.modified >= :cutoffdate AND r.id is NULL
    1978                     $groupselect
    1979                     $timedsql
    1980            GROUP BY d.id";
    1981      $params['cutoffdate'] = $cutoffdate;
    1982  
    1983      if ($unreads = $DB->get_records_sql($sql, $params)) {
    1984          foreach ($unreads as $unread) {
    1985              $unreads[$unread->id] = $unread->unread;
    1986          }
    1987          return $unreads;
    1988      } else {
    1989          return array();
    1990      }
    1991  }
    1992  
    1993  /**
    1994   * @global object
    1995   * @global object
    1996   * @global object
    1997   * @uses CONEXT_MODULE
    1998   * @uses VISIBLEGROUPS
    1999   * @param object $cm
    2000   * @return array
    2001   */
    2002  function forum_get_discussions_count($cm) {
    2003      global $CFG, $DB, $USER;
    2004  
    2005      $now = floor(time() / 60) * 60;
    2006      $params = array($cm->instance);
    2007      $groupmode    = groups_get_activity_groupmode($cm);
    2008      $currentgroup = groups_get_activity_group($cm);
    2009  
    2010      if ($groupmode) {
    2011          $modcontext = context_module::instance($cm->id);
    2012  
    2013          if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {
    2014              if ($currentgroup) {
    2015                  $groupselect = "AND (d.groupid = ? OR d.groupid = -1)";
    2016                  $params[] = $currentgroup;
    2017              } else {
    2018                  $groupselect = "";
    2019              }
    2020  
    2021          } else {
    2022              //seprate groups without access all
    2023              if ($currentgroup) {
    2024                  $groupselect = "AND (d.groupid = ? OR d.groupid = -1)";
    2025                  $params[] = $currentgroup;
    2026              } else {
    2027                  $groupselect = "AND d.groupid = -1";
    2028              }
    2029          }
    2030      } else {
    2031          $groupselect = "";
    2032      }
    2033  
    2034      $timelimit = "";
    2035  
    2036      if (!empty($CFG->forum_enabletimedposts)) {
    2037  
    2038          $modcontext = context_module::instance($cm->id);
    2039  
    2040          if (!has_capability('mod/forum:viewhiddentimedposts', $modcontext)) {
    2041              $timelimit = " AND ((d.timestart <= ? AND (d.timeend = 0 OR d.timeend > ?))";
    2042              $params[] = $now;
    2043              $params[] = $now;
    2044              if (isloggedin()) {
    2045                  $timelimit .= " OR d.userid = ?";
    2046                  $params[] = $USER->id;
    2047              }
    2048              $timelimit .= ")";
    2049          }
    2050      }
    2051  
    2052      $sql = "SELECT COUNT(d.id)
    2053                FROM {forum_discussions} d
    2054                     JOIN {forum_posts} p ON p.discussion = d.id
    2055               WHERE d.forum = ? AND p.parent = 0
    2056                     $groupselect $timelimit";
    2057  
    2058      return $DB->get_field_sql($sql, $params);
    2059  }
    2060  
    2061  
    2062  // OTHER FUNCTIONS ///////////////////////////////////////////////////////////
    2063  
    2064  
    2065  /**
    2066   * @global object
    2067   * @global object
    2068   * @param int $courseid
    2069   * @param string $type
    2070   */
    2071  function forum_get_course_forum($courseid, $type) {
    2072  // How to set up special 1-per-course forums
    2073      global $CFG, $DB, $OUTPUT, $USER;
    2074  
    2075      if ($forums = $DB->get_records_select("forum", "course = ? AND type = ?", array($courseid, $type), "id ASC")) {
    2076          // There should always only be ONE, but with the right combination of
    2077          // errors there might be more.  In this case, just return the oldest one (lowest ID).
    2078          foreach ($forums as $forum) {
    2079              return $forum;   // ie the first one
    2080          }
    2081      }
    2082  
    2083      // Doesn't exist, so create one now.
    2084      $forum = new stdClass();
    2085      $forum->course = $courseid;
    2086      $forum->type = "$type";
    2087      if (!empty($USER->htmleditor)) {
    2088          $forum->introformat = $USER->htmleditor;
    2089      }
    2090      switch ($forum->type) {
    2091          case "news":
    2092              $forum->name  = get_string("namenews", "forum");
    2093              $forum->intro = get_string("intronews", "forum");
    2094              $forum->introformat = FORMAT_HTML;
    2095              $forum->forcesubscribe = FORUM_FORCESUBSCRIBE;
    2096              $forum->assessed = 0;
    2097              if ($courseid == SITEID) {
    2098                  $forum->name  = get_string("sitenews");
    2099                  $forum->forcesubscribe = 0;
    2100              }
    2101              break;
    2102          case "social":
    2103              $forum->name  = get_string("namesocial", "forum");
    2104              $forum->intro = get_string("introsocial", "forum");
    2105              $forum->introformat = FORMAT_HTML;
    2106              $forum->assessed = 0;
    2107              $forum->forcesubscribe = 0;
    2108              break;
    2109          case "blog":
    2110              $forum->name = get_string('blogforum', 'forum');
    2111              $forum->intro = get_string('introblog', 'forum');
    2112              $forum->introformat = FORMAT_HTML;
    2113              $forum->assessed = 0;
    2114              $forum->forcesubscribe = 0;
    2115              break;
    2116          default:
    2117              echo $OUTPUT->notification("That forum type doesn't exist!");
    2118              return false;
    2119              break;
    2120      }
    2121  
    2122      $forum->timemodified = time();
    2123      $forum->id = $DB->insert_record("forum", $forum);
    2124  
    2125      if (! $module = $DB->get_record("modules", array("name" => "forum"))) {
    2126          echo $OUTPUT->notification("Could not find forum module!!");
    2127          return false;
    2128      }
    2129      $mod = new stdClass();
    2130      $mod->course = $courseid;
    2131      $mod->module = $module->id;
    2132      $mod->instance = $forum->id;
    2133      $mod->section = 0;
    2134      include_once("$CFG->dirroot/course/lib.php");
    2135      if (! $mod->coursemodule = add_course_module($mod) ) {
    2136          echo $OUTPUT->notification("Could not add a new course module to the course '" . $courseid . "'");
    2137          return false;
    2138      }
    2139      $sectionid = course_add_cm_to_section($courseid, $mod->coursemodule, 0);
    2140      return $DB->get_record("forum", array("id" => "$forum->id"));
    2141  }
    2142  
    2143  /**
    2144   * Return rating related permissions
    2145   *
    2146   * @param string $options the context id
    2147   * @return array an associative array of the user's rating permissions
    2148   */
    2149  function forum_rating_permissions($contextid, $component, $ratingarea) {
    2150      $context = context::instance_by_id($contextid, MUST_EXIST);
    2151      if ($component != 'mod_forum' || $ratingarea != 'post') {
    2152          // We don't know about this component/ratingarea so just return null to get the
    2153          // default restrictive permissions.
    2154          return null;
    2155      }
    2156      return array(
    2157          'view'    => has_capability('mod/forum:viewrating', $context),
    2158          'viewany' => has_capability('mod/forum:viewanyrating', $context),
    2159          'viewall' => has_capability('mod/forum:viewallratings', $context),
    2160          'rate'    => has_capability('mod/forum:rate', $context)
    2161      );
    2162  }
    2163  
    2164  /**
    2165   * Validates a submitted rating
    2166   * @param array $params submitted data
    2167   *            context => object the context in which the rated items exists [required]
    2168   *            component => The component for this module - should always be mod_forum [required]
    2169   *            ratingarea => object the context in which the rated items exists [required]
    2170   *
    2171   *            itemid => int the ID of the object being rated [required]
    2172   *            scaleid => int the scale from which the user can select a rating. Used for bounds checking. [required]
    2173   *            rating => int the submitted rating [required]
    2174   *            rateduserid => int the id of the user whose items have been rated. NOT the user who submitted the ratings. 0 to update all. [required]
    2175   *            aggregation => int the aggregation method to apply when calculating grades ie RATING_AGGREGATE_AVERAGE [required]
    2176   * @return boolean true if the rating is valid. Will throw rating_exception if not
    2177   */
    2178  function forum_rating_validate($params) {
    2179      global $DB, $USER;
    2180  
    2181      // Check the component is mod_forum
    2182      if ($params['component'] != 'mod_forum') {
    2183          throw new rating_exception('invalidcomponent');
    2184      }
    2185  
    2186      // Check the ratingarea is post (the only rating area in forum)
    2187      if ($params['ratingarea'] != 'post') {
    2188          throw new rating_exception('invalidratingarea');
    2189      }
    2190  
    2191      // Check the rateduserid is not the current user .. you can't rate your own posts
    2192      if ($params['rateduserid'] == $USER->id) {
    2193          throw new rating_exception('nopermissiontorate');
    2194      }
    2195  
    2196      // Fetch all the related records ... we need to do this anyway to call forum_user_can_see_post
    2197      $post = $DB->get_record('forum_posts', array('id' => $params['itemid'], 'userid' => $params['rateduserid']), '*', MUST_EXIST);
    2198      $discussion = $DB->get_record('forum_discussions', array('id' => $post->discussion), '*', MUST_EXIST);
    2199      $forum = $DB->get_record('forum', array('id' => $discussion->forum), '*', MUST_EXIST);
    2200      $course = $DB->get_record('course', array('id' => $forum->course), '*', MUST_EXIST);
    2201      $cm = get_coursemodule_from_instance('forum', $forum->id, $course->id , false, MUST_EXIST);
    2202      $context = context_module::instance($cm->id);
    2203  
    2204      // Make sure the context provided is the context of the forum
    2205      if ($context->id != $params['context']->id) {
    2206          throw new rating_exception('invalidcontext');
    2207      }
    2208  
    2209      if ($forum->scale != $params['scaleid']) {
    2210          //the scale being submitted doesnt match the one in the database
    2211          throw new rating_exception('invalidscaleid');
    2212      }
    2213  
    2214      // check the item we're rating was created in the assessable time window
    2215      if (!empty($forum->assesstimestart) && !empty($forum->assesstimefinish)) {
    2216          if ($post->created < $forum->assesstimestart || $post->created > $forum->assesstimefinish) {
    2217              throw new rating_exception('notavailable');
    2218          }
    2219      }
    2220  
    2221      //check that the submitted rating is valid for the scale
    2222  
    2223      // lower limit
    2224      if ($params['rating'] < 0  && $params['rating'] != RATING_UNSET_RATING) {
    2225          throw new rating_exception('invalidnum');
    2226      }
    2227  
    2228      // upper limit
    2229      if ($forum->scale < 0) {
    2230          //its a custom scale
    2231          $scalerecord = $DB->get_record('scale', array('id' => -$forum->scale));
    2232          if ($scalerecord) {
    2233              $scalearray = explode(',', $scalerecord->scale);
    2234              if ($params['rating'] > count($scalearray)) {
    2235                  throw new rating_exception('invalidnum');
    2236              }
    2237          } else {
    2238              throw new rating_exception('invalidscaleid');
    2239          }
    2240      } else if ($params['rating'] > $forum->scale) {
    2241          //if its numeric and submitted rating is above maximum
    2242          throw new rating_exception('invalidnum');
    2243      }
    2244  
    2245      // Make sure groups allow this user to see the item they're rating
    2246      if ($discussion->groupid > 0 and $groupmode = groups_get_activity_groupmode($cm, $course)) {   // Groups are being used
    2247          if (!groups_group_exists($discussion->groupid)) { // Can't find group
    2248              throw new rating_exception('cannotfindgroup');//something is wrong
    2249          }
    2250  
    2251          if (!groups_is_member($discussion->groupid) and !has_capability('moodle/site:accessallgroups', $context)) {
    2252              // do not allow rating of posts from other groups when in SEPARATEGROUPS or VISIBLEGROUPS
    2253              throw new rating_exception('notmemberofgroup');
    2254          }
    2255      }
    2256  
    2257      // perform some final capability checks
    2258      if (!forum_user_can_see_post($forum, $discussion, $post, $USER, $cm)) {
    2259          throw new rating_exception('nopermissiontorate');
    2260      }
    2261  
    2262      return true;
    2263  }
    2264  
    2265  /**
    2266   * Can the current user see ratings for a given itemid?
    2267   *
    2268   * @param array $params submitted data
    2269   *            contextid => int contextid [required]
    2270   *            component => The component for this module - should always be mod_forum [required]
    2271   *            ratingarea => object the context in which the rated items exists [required]
    2272   *            itemid => int the ID of the object being rated [required]
    2273   *            scaleid => int scale id [optional]
    2274   * @return bool
    2275   * @throws coding_exception
    2276   * @throws rating_exception
    2277   */
    2278  function mod_forum_rating_can_see_item_ratings($params) {
    2279      global $DB, $USER;
    2280  
    2281      // Check the component is mod_forum.
    2282      if (!isset($params['component']) || $params['component'] != 'mod_forum') {
    2283          throw new rating_exception('invalidcomponent');
    2284      }
    2285  
    2286      // Check the ratingarea is post (the only rating area in forum).
    2287      if (!isset($params['ratingarea']) || $params['ratingarea'] != 'post') {
    2288          throw new rating_exception('invalidratingarea');
    2289      }
    2290  
    2291      if (!isset($params['itemid'])) {
    2292          throw new rating_exception('invaliditemid');
    2293      }
    2294  
    2295      $post = $DB->get_record('forum_posts', array('id' => $params['itemid']), '*', MUST_EXIST);
    2296      $discussion = $DB->get_record('forum_discussions', array('id' => $post->discussion), '*', MUST_EXIST);
    2297      $forum = $DB->get_record('forum', array('id' => $discussion->forum), '*', MUST_EXIST);
    2298      $course = $DB->get_record('course', array('id' => $forum->course), '*', MUST_EXIST);
    2299      $cm = get_coursemodule_from_instance('forum', $forum->id, $course->id , false, MUST_EXIST);
    2300  
    2301      // Perform some final capability checks.
    2302      if (!forum_user_can_see_post($forum, $discussion, $post, $USER, $cm)) {
    2303          return false;
    2304      }
    2305  
    2306      return true;
    2307  }
    2308  
    2309  /**
    2310   * This function prints the overview of a discussion in the forum listing.
    2311   * It needs some discussion information and some post information, these
    2312   * happen to be combined for efficiency in the $post parameter by the function
    2313   * that calls this one: forum_print_latest_discussions()
    2314   *
    2315   * @global object
    2316   * @global object
    2317   * @param object $post The post object (passed by reference for speed).
    2318   * @param object $forum The forum object.
    2319   * @param int $group Current group.
    2320   * @param string $datestring Format to use for the dates.
    2321   * @param boolean $cantrack Is tracking enabled for this forum.
    2322   * @param boolean $forumtracked Is the user tracking this forum.
    2323   * @param boolean $canviewparticipants True if user has the viewparticipants permission for this course
    2324   * @param boolean $canviewhiddentimedposts True if user has the viewhiddentimedposts permission for this forum
    2325   */
    2326  function forum_print_discussion_header(&$post, $forum, $group = -1, $datestring = "",
    2327                                          $cantrack = true, $forumtracked = true, $canviewparticipants = true, $modcontext = null,
    2328                                          $canviewhiddentimedposts = false) {
    2329  
    2330      global $COURSE, $USER, $CFG, $OUTPUT, $PAGE;
    2331  
    2332      static $rowcount;
    2333      static $strmarkalldread;
    2334  
    2335      if (empty($modcontext)) {
    2336          if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
    2337              print_error('invalidcoursemodule');
    2338          }
    2339          $modcontext = context_module::instance($cm->id);
    2340      }
    2341  
    2342      if (!isset($rowcount)) {
    2343          $rowcount = 0;
    2344          $strmarkalldread = get_string('markalldread', 'forum');
    2345      } else {
    2346          $rowcount = ($rowcount + 1) % 2;
    2347      }
    2348  
    2349      $post->subject = format_string($post->subject,true);
    2350  
    2351      $canviewfullnames = has_capability('moodle/site:viewfullnames', $modcontext);
    2352      $timeddiscussion = !empty($CFG->forum_enabletimedposts) && ($post->timestart || $post->timeend);
    2353      $timedoutsidewindow = '';
    2354      if ($timeddiscussion && ($post->timestart > time() || ($post->timeend != 0 && $post->timeend < time()))) {
    2355          $timedoutsidewindow = ' dimmed_text';
    2356      }
    2357  
    2358      echo "\n\n";
    2359      echo '<tr class="discussion r'.$rowcount.$timedoutsidewindow.'">';
    2360  
    2361      $topicclass = 'topic starter';
    2362      if (FORUM_DISCUSSION_PINNED == $post->pinned) {
    2363          $topicclass .= ' pinned';
    2364      }
    2365      echo '<td class="'.$topicclass.'">';
    2366      if (FORUM_DISCUSSION_PINNED == $post->pinned) {
    2367          echo $OUTPUT->pix_icon('i/pinned', get_string('discussionpinned', 'forum'), 'mod_forum');
    2368      }
    2369      $canalwaysseetimedpost = $USER->id == $post->userid || $canviewhiddentimedposts;
    2370      if ($timeddiscussion && $canalwaysseetimedpost) {
    2371          echo $PAGE->get_renderer('mod_forum')->timed_discussion_tooltip($post, empty($timedoutsidewindow));
    2372      }
    2373  
    2374      echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">'.$post->subject.'</a>';
    2375      echo "</td>\n";
    2376  
    2377      // Picture
    2378      $postuser = new stdClass();
    2379      $postuserfields = explode(',', implode(',', \core_user\fields::get_picture_fields()));
    2380      $postuser = username_load_fields_from_object($postuser, $post, null, $postuserfields);
    2381      $postuser->id = $post->userid;
    2382      echo '<td class="author">';
    2383      echo '<div class="media">';
    2384      echo '<span class="float-left">';
    2385      echo $OUTPUT->user_picture($postuser, array('courseid'=>$forum->course));
    2386      echo '</span>';
    2387      // User name
    2388      echo '<div class="media-body">';
    2389      $fullname = fullname($postuser, $canviewfullnames);
    2390      echo '<a href="'.$CFG->wwwroot.'/user/view.php?id='.$post->userid.'&amp;course='.$forum->course.'">'.$fullname.'</a>';
    2391      echo '</div>';
    2392      echo '</div>';
    2393      echo "</td>\n";
    2394  
    2395      // Group picture
    2396      if ($group !== -1) {  // Groups are active - group is a group data object or NULL
    2397          echo '<td class="picture group">';
    2398          if (!empty($group->picture)) {
    2399              if ($canviewparticipants && $COURSE->groupmode) {
    2400                  $picturelink = true;
    2401              } else {
    2402                  $picturelink = false;
    2403              }
    2404              print_group_picture($group, $forum->course, false, false, $picturelink);
    2405          } else if (isset($group->id)) {
    2406              if ($canviewparticipants && $COURSE->groupmode) {
    2407                  echo '<a href="'.$CFG->wwwroot.'/user/index.php?id='.$forum->course.'&amp;group='.$group->id.'">'.$group->name.'</a>';
    2408              } else {
    2409                  echo $group->name;
    2410              }
    2411          }
    2412          echo "</td>\n";
    2413      }
    2414  
    2415      if (has_capability('mod/forum:viewdiscussion', $modcontext)) {   // Show the column with replies
    2416          echo '<td class="replies">';
    2417          echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">';
    2418          echo $post->replies.'</a>';
    2419          echo "</td>\n";
    2420  
    2421          if ($cantrack) {
    2422              echo '<td class="replies">';
    2423              if ($forumtracked) {
    2424                  if ($post->unread > 0) {
    2425                      echo '<span class="unread">';
    2426                      echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'#unread">';
    2427                      echo $post->unread;
    2428                      echo '</a>';
    2429                      echo '<a title="'.$strmarkalldread.'" href="'.$CFG->wwwroot.'/mod/forum/markposts.php?f='.
    2430                           $forum->id.'&amp;d='.$post->discussion.'&amp;mark=read&amp;return=/mod/forum/view.php&amp;sesskey=' .
    2431                           sesskey() . '">' . $OUTPUT->pix_icon('t/markasread', $strmarkalldread) . '</a>';
    2432                      echo '</span>';
    2433                  } else {
    2434                      echo '<span class="read">';
    2435                      echo $post->unread;
    2436                      echo '</span>';
    2437                  }
    2438              } else {
    2439                  echo '<span class="read">';
    2440                  echo '-';
    2441                  echo '</span>';
    2442              }
    2443              echo "</td>\n";
    2444          }
    2445      }
    2446  
    2447      echo '<td class="lastpost">';
    2448      $usedate = (empty($post->timemodified)) ? $post->created : $post->timemodified;
    2449      $parenturl = '';
    2450      $usermodified = new stdClass();
    2451      $usermodified->id = $post->usermodified;
    2452      $usermodified = username_load_fields_from_object($usermodified, $post, 'um');
    2453  
    2454      // In QA forums we check that the user can view participants.
    2455      if ($forum->type !== 'qanda' || $canviewparticipants) {
    2456          echo '<a href="'.$CFG->wwwroot.'/user/view.php?id='.$post->usermodified.'&amp;course='.$forum->course.'">'.
    2457               fullname($usermodified, $canviewfullnames).'</a><br />';
    2458          $parenturl = (empty($post->lastpostid)) ? '' : '&amp;parent='.$post->lastpostid;
    2459      }
    2460  
    2461      echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.$parenturl.'">'.
    2462            userdate_htmltime($usedate, $datestring).'</a>';
    2463      echo "</td>\n";
    2464  
    2465      // is_guest should be used here as this also checks whether the user is a guest in the current course.
    2466      // Guests and visitors cannot subscribe - only enrolled users.
    2467      if ((!is_guest($modcontext, $USER) && isloggedin()) && has_capability('mod/forum:viewdiscussion', $modcontext)) {
    2468          // Discussion subscription.
    2469          if (\mod_forum\subscriptions::is_subscribable($forum)) {
    2470              echo '<td class="discussionsubscription">';
    2471              echo forum_get_discussion_subscription_icon($forum, $post->discussion);
    2472              echo '</td>';
    2473          }
    2474      }
    2475  
    2476      echo "</tr>\n\n";
    2477  
    2478  }
    2479  
    2480  /**
    2481   * Return the markup for the discussion subscription toggling icon.
    2482   *
    2483   * @param stdClass $forum The forum object.
    2484   * @param int $discussionid The discussion to create an icon for.
    2485   * @return string The generated markup.
    2486   */
    2487  function forum_get_discussion_subscription_icon($forum, $discussionid, $returnurl = null, $includetext = false) {
    2488      global $USER, $OUTPUT, $PAGE;
    2489  
    2490      if ($returnurl === null && $PAGE->url) {
    2491          $returnurl = $PAGE->url->out();
    2492      }
    2493  
    2494      $o = '';
    2495      $subscriptionstatus = \mod_forum\subscriptions::is_subscribed($USER->id, $forum, $discussionid);
    2496      $subscriptionlink = new moodle_url('/mod/forum/subscribe.php', array(
    2497          'sesskey' => sesskey(),
    2498          'id' => $forum->id,
    2499          'd' => $discussionid,
    2500          'returnurl' => $returnurl,
    2501      ));
    2502  
    2503      if ($includetext) {
    2504          $o .= $subscriptionstatus ? get_string('subscribed', 'mod_forum') : get_string('notsubscribed', 'mod_forum');
    2505      }
    2506  
    2507      if ($subscriptionstatus) {
    2508          $output = $OUTPUT->pix_icon('t/subscribed', get_string('clicktounsubscribe', 'forum'), 'mod_forum');
    2509          if ($includetext) {
    2510              $output .= get_string('subscribed', 'mod_forum');
    2511          }
    2512  
    2513          return html_writer::link($subscriptionlink, $output, array(
    2514                  'title' => get_string('clicktounsubscribe', 'forum'),
    2515                  'class' => 'discussiontoggle btn btn-link',
    2516                  'data-forumid' => $forum->id,
    2517                  'data-discussionid' => $discussionid,
    2518                  'data-includetext' => $includetext,
    2519              ));
    2520  
    2521      } else {
    2522          $output = $OUTPUT->pix_icon('t/unsubscribed', get_string('clicktosubscribe', 'forum'), 'mod_forum');
    2523          if ($includetext) {
    2524              $output .= get_string('notsubscribed', 'mod_forum');
    2525          }
    2526  
    2527          return html_writer::link($subscriptionlink, $output, array(
    2528                  'title' => get_string('clicktosubscribe', 'forum'),
    2529                  'class' => 'discussiontoggle btn btn-link',
    2530                  'data-forumid' => $forum->id,
    2531                  'data-discussionid' => $discussionid,
    2532                  'data-includetext' => $includetext,
    2533              ));
    2534      }
    2535  }
    2536  
    2537  /**
    2538   * Return a pair of spans containing classes to allow the subscribe and
    2539   * unsubscribe icons to be pre-loaded by a browser.
    2540   *
    2541   * @return string The generated markup
    2542   */
    2543  function forum_get_discussion_subscription_icon_preloaders() {
    2544      $o = '';
    2545      $o .= html_writer::span('&nbsp;', 'preload-subscribe');
    2546      $o .= html_writer::span('&nbsp;', 'preload-unsubscribe');
    2547      return $o;
    2548  }
    2549  
    2550  /**
    2551   * Print the drop down that allows the user to select how they want to have
    2552   * the discussion displayed.
    2553   *
    2554   * @param int $id forum id if $forumtype is 'single',
    2555   *              discussion id for any other forum type
    2556   * @param mixed $mode forum layout mode
    2557   * @param string $forumtype optional
    2558   */
    2559  function forum_print_mode_form($id, $mode, $forumtype='') {
    2560      global $OUTPUT;
    2561      $useexperimentalui = get_user_preferences('forum_useexperimentalui', false);
    2562      if ($forumtype == 'single') {
    2563          $select = new single_select(
    2564              new moodle_url("/mod/forum/view.php",
    2565              array('f' => $id)),
    2566              'mode',
    2567              forum_get_layout_modes($useexperimentalui),
    2568              $mode,
    2569              null,
    2570              "mode"
    2571          );
    2572          $select->set_label(get_string('displaymode', 'forum'), array('class' => 'accesshide'));
    2573          $select->class = "forummode";
    2574      } else {
    2575          $select = new single_select(
    2576              new moodle_url("/mod/forum/discuss.php",
    2577              array('d' => $id)),
    2578              'mode',
    2579              forum_get_layout_modes($useexperimentalui),
    2580              $mode,
    2581              null,
    2582              "mode"
    2583          );
    2584          $select->set_label(get_string('displaymode', 'forum'), array('class' => 'accesshide'));
    2585      }
    2586      echo $OUTPUT->render($select);
    2587  }
    2588  
    2589  /**
    2590   * @global object
    2591   * @param object $course
    2592   * @param string $search
    2593   * @return string
    2594   */
    2595  function forum_search_form($course, $search='') {
    2596      global $CFG, $PAGE;
    2597      $forumsearch = new \mod_forum\output\quick_search_form($course->id, $search);
    2598      $output = $PAGE->get_renderer('mod_forum');
    2599      return $output->render($forumsearch);
    2600  }
    2601  
    2602  
    2603  /**
    2604   * @global object
    2605   * @global object
    2606   */
    2607  function forum_set_return() {
    2608      global $CFG, $SESSION;
    2609  
    2610      if (! isset($SESSION->fromdiscussion)) {
    2611          $referer = get_local_referer(false);
    2612          // If the referer is NOT a login screen then save it.
    2613          if (! strncasecmp("$CFG->wwwroot/login", $referer, 300)) {
    2614              $SESSION->fromdiscussion = $referer;
    2615          }
    2616      }
    2617  }
    2618  
    2619  
    2620  /**
    2621   * @global object
    2622   * @param string|\moodle_url $default
    2623   * @return string
    2624   */
    2625  function forum_go_back_to($default) {
    2626      global $SESSION;
    2627  
    2628      if (!empty($SESSION->fromdiscussion)) {
    2629          $returnto = $SESSION->fromdiscussion;
    2630          unset($SESSION->fromdiscussion);
    2631          return $returnto;
    2632      } else {
    2633          return $default;
    2634      }
    2635  }
    2636  
    2637  /**
    2638   * Given a discussion object that is being moved to $forumto,
    2639   * this function checks all posts in that discussion
    2640   * for attachments, and if any are found, these are
    2641   * moved to the new forum directory.
    2642   *
    2643   * @global object
    2644   * @param object $discussion
    2645   * @param int $forumfrom source forum id
    2646   * @param int $forumto target forum id
    2647   * @return bool success
    2648   */
    2649  function forum_move_attachments($discussion, $forumfrom, $forumto) {
    2650      global $DB;
    2651  
    2652      $fs = get_file_storage();
    2653  
    2654      $newcm = get_coursemodule_from_instance('forum', $forumto);
    2655      $oldcm = get_coursemodule_from_instance('forum', $forumfrom);
    2656  
    2657      $newcontext = context_module::instance($newcm->id);
    2658      $oldcontext = context_module::instance($oldcm->id);
    2659  
    2660      // loop through all posts, better not use attachment flag ;-)
    2661      if ($posts = $DB->get_records('forum_posts', array('discussion'=>$discussion->id), '', 'id, attachment')) {
    2662          foreach ($posts as $post) {
    2663              $fs->move_area_files_to_new_context($oldcontext->id,
    2664                      $newcontext->id, 'mod_forum', 'post', $post->id);
    2665              $attachmentsmoved = $fs->move_area_files_to_new_context($oldcontext->id,
    2666                      $newcontext->id, 'mod_forum', 'attachment', $post->id);
    2667              if ($attachmentsmoved > 0 && $post->attachment != '1') {
    2668                  // Weird - let's fix it
    2669                  $post->attachment = '1';
    2670                  $DB->update_record('forum_posts', $post);
    2671              } else if ($attachmentsmoved == 0 && $post->attachment != '') {
    2672                  // Weird - let's fix it
    2673                  $post->attachment = '';
    2674                  $DB->update_record('forum_posts', $post);
    2675              }
    2676          }
    2677      }
    2678  
    2679      return true;
    2680  }
    2681  
    2682  /**
    2683   * Returns attachments as formated text/html optionally with separate images
    2684   *
    2685   * @global object
    2686   * @global object
    2687   * @global object
    2688   * @param object $post
    2689   * @param object $cm
    2690   * @param string $type html/text/separateimages
    2691   * @return mixed string or array of (html text withouth images and image HTML)
    2692   */
    2693  function forum_print_attachments($post, $cm, $type) {
    2694      global $CFG, $DB, $USER, $OUTPUT;
    2695  
    2696      if (empty($post->attachment)) {
    2697          return $type !== 'separateimages' ? '' : array('', '');
    2698      }
    2699  
    2700      if (!in_array($type, array('separateimages', 'html', 'text'))) {
    2701          return $type !== 'separateimages' ? '' : array('', '');
    2702      }
    2703  
    2704      if (!$context = context_module::instance($cm->id)) {
    2705          return $type !== 'separateimages' ? '' : array('', '');
    2706      }
    2707      $strattachment = get_string('attachment', 'forum');
    2708  
    2709      $fs = get_file_storage();
    2710  
    2711      $imagereturn = '';
    2712      $output = '';
    2713  
    2714      $canexport = !empty($CFG->enableportfolios) && (has_capability('mod/forum:exportpost', $context) || ($post->userid == $USER->id && has_capability('mod/forum:exportownpost', $context)));
    2715  
    2716      if ($canexport) {
    2717          require_once($CFG->libdir.'/portfoliolib.php');
    2718      }
    2719  
    2720      // We retrieve all files according to the time that they were created.  In the case that several files were uploaded
    2721      // at the sametime (e.g. in the case of drag/drop upload) we revert to using the filename.
    2722      $files = $fs->get_area_files($context->id, 'mod_forum', 'attachment', $post->id, "filename", false);
    2723      if ($files) {
    2724          if ($canexport) {
    2725              $button = new portfolio_add_button();
    2726          }
    2727          foreach ($files as $file) {
    2728              $filename = $file->get_filename();
    2729              $mimetype = $file->get_mimetype();
    2730              $iconimage = $OUTPUT->pix_icon(file_file_icon($file), get_mimetype_description($file), 'moodle', array('class' => 'icon'));
    2731              $path = file_encode_url($CFG->wwwroot.'/pluginfile.php', '/'.$context->id.'/mod_forum/attachment/'.$post->id.'/'.$filename);
    2732  
    2733              if ($type == 'html') {
    2734                  $output .= "<a href=\"$path\">$iconimage</a> ";
    2735                  $output .= "<a href=\"$path\">".s($filename)."</a>";
    2736                  if ($canexport) {
    2737                      $button->set_callback_options('forum_portfolio_caller', array('postid' => $post->id, 'attachment' => $file->get_id()), 'mod_forum');
    2738                      $button->set_format_by_file($file);
    2739                      $output .= $button->to_html(PORTFOLIO_ADD_ICON_LINK);
    2740                  }
    2741                  $output .= "<br />";
    2742  
    2743              } else if ($type == 'text') {
    2744                  $output .= "$strattachment ".s($filename).":\n$path\n";
    2745  
    2746              } else { //'returnimages'
    2747                  if (in_array($mimetype, array('image/gif', 'image/jpeg', 'image/png'))) {
    2748                      // Image attachments don't get printed as links
    2749                      $imagereturn .= "<br /><img src=\"$path\" alt=\"\" />";
    2750                      if ($canexport) {
    2751                          $button->set_callback_options('forum_portfolio_caller', array('postid' => $post->id, 'attachment' => $file->get_id()), 'mod_forum');
    2752                          $button->set_format_by_file($file);
    2753                          $imagereturn .= $button->to_html(PORTFOLIO_ADD_ICON_LINK);
    2754                      }
    2755                  } else {
    2756                      $output .= "<a href=\"$path\">$iconimage</a> ";
    2757                      $output .= format_text("<a href=\"$path\">".s($filename)."</a>", FORMAT_HTML, array('context'=>$context));
    2758                      if ($canexport) {
    2759                          $button->set_callback_options('forum_portfolio_caller', array('postid' => $post->id, 'attachment' => $file->get_id()), 'mod_forum');
    2760                          $button->set_format_by_file($file);
    2761                          $output .= $button->to_html(PORTFOLIO_ADD_ICON_LINK);
    2762                      }
    2763                      $output .= '<br />';
    2764                  }
    2765              }
    2766  
    2767              if (!empty($CFG->enableplagiarism)) {
    2768                  require_once($CFG->libdir.'/plagiarismlib.php');
    2769                  $output .= plagiarism_get_links(array('userid' => $post->userid,
    2770                      'file' => $file,
    2771                      'cmid' => $cm->id,
    2772                      'course' => $cm->course,
    2773                      'forum' => $cm->instance));
    2774                  $output .= '<br />';
    2775              }
    2776          }
    2777      }
    2778  
    2779      if ($type !== 'separateimages') {
    2780          return $output;
    2781  
    2782      } else {
    2783          return array($output, $imagereturn);
    2784      }
    2785  }
    2786  
    2787  ////////////////////////////////////////////////////////////////////////////////
    2788  // File API                                                                   //
    2789  ////////////////////////////////////////////////////////////////////////////////
    2790  
    2791  /**
    2792   * Lists all browsable file areas
    2793   *
    2794   * @package  mod_forum
    2795   * @category files
    2796   * @param stdClass $course course object
    2797   * @param stdClass $cm course module object
    2798   * @param stdClass $context context object
    2799   * @return array
    2800   */
    2801  function forum_get_file_areas($course, $cm, $context) {
    2802      return array(
    2803          'attachment' => get_string('areaattachment', 'mod_forum'),
    2804          'post' => get_string('areapost', 'mod_forum'),
    2805      );
    2806  }
    2807  
    2808  /**
    2809   * File browsing support for forum module.
    2810   *
    2811   * @package  mod_forum
    2812   * @category files
    2813   * @param stdClass $browser file browser object
    2814   * @param stdClass $areas file areas
    2815   * @param stdClass $course course object
    2816   * @param stdClass $cm course module
    2817   * @param stdClass $context context module
    2818   * @param string $filearea file area
    2819   * @param int $itemid item ID
    2820   * @param string $filepath file path
    2821   * @param string $filename file name
    2822   * @return file_info instance or null if not found
    2823   */
    2824  function forum_get_file_info($browser, $areas, $course, $cm, $context, $filearea, $itemid, $filepath, $filename) {
    2825      global $CFG, $DB, $USER;
    2826  
    2827      if ($context->contextlevel != CONTEXT_MODULE) {
    2828          return null;
    2829      }
    2830  
    2831      // filearea must contain a real area
    2832      if (!isset($areas[$filearea])) {
    2833          return null;
    2834      }
    2835  
    2836      // Note that forum_user_can_see_post() additionally allows access for parent roles
    2837      // and it explicitly checks qanda forum type, too. One day, when we stop requiring
    2838      // course:managefiles, we will need to extend this.
    2839      if (!has_capability('mod/forum:viewdiscussion', $context)) {
    2840          return null;
    2841      }
    2842  
    2843      if (is_null($itemid)) {
    2844          require_once($CFG->dirroot.'/mod/forum/locallib.php');
    2845          return new forum_file_info_container($browser, $course, $cm, $context, $areas, $filearea);
    2846      }
    2847  
    2848      static $cached = array();
    2849      // $cached will store last retrieved post, discussion and forum. To make sure that the cache
    2850      // is cleared between unit tests we check if this is the same session
    2851      if (!isset($cached['sesskey']) || $cached['sesskey'] != sesskey()) {
    2852          $cached = array('sesskey' => sesskey());
    2853      }
    2854  
    2855      if (isset($cached['post']) && $cached['post']->id == $itemid) {
    2856          $post = $cached['post'];
    2857      } else if ($post = $DB->get_record('forum_posts', array('id' => $itemid))) {
    2858          $cached['post'] = $post;
    2859      } else {
    2860          return null;
    2861      }
    2862  
    2863      if (isset($cached['discussion']) && $cached['discussion']->id == $post->discussion) {
    2864          $discussion = $cached['discussion'];
    2865      } else if ($discussion = $DB->get_record('forum_discussions', array('id' => $post->discussion))) {
    2866          $cached['discussion'] = $discussion;
    2867      } else {
    2868          return null;
    2869      }
    2870  
    2871      if (isset($cached['forum']) && $cached['forum']->id == $cm->instance) {
    2872          $forum = $cached['forum'];
    2873      } else if ($forum = $DB->get_record('forum', array('id' => $cm->instance))) {
    2874          $cached['forum'] = $forum;
    2875      } else {
    2876          return null;
    2877      }
    2878  
    2879      $fs = get_file_storage();
    2880      $filepath = is_null($filepath) ? '/' : $filepath;
    2881      $filename = is_null($filename) ? '.' : $filename;
    2882      if (!($storedfile = $fs->get_file($context->id, 'mod_forum', $filearea, $itemid, $filepath, $filename))) {
    2883          return null;
    2884      }
    2885  
    2886      // Checks to see if the user can manage files or is the owner.
    2887      // TODO MDL-33805 - Do not use userid here and move the capability check above.
    2888      if (!has_capability('moodle/course:managefiles', $context) && $storedfile->get_userid() != $USER->id) {
    2889          return null;
    2890      }
    2891      // Make sure groups allow this user to see this file
    2892      if ($discussion->groupid > 0 && !has_capability('moodle/site:accessallgroups', $context)) {
    2893          $groupmode = groups_get_activity_groupmode($cm, $course);
    2894          if ($groupmode == SEPARATEGROUPS && !groups_is_member($discussion->groupid)) {
    2895              return null;
    2896          }
    2897      }
    2898  
    2899      // Make sure we're allowed to see it...
    2900      if (!forum_user_can_see_post($forum, $discussion, $post, NULL, $cm)) {
    2901          return null;
    2902      }
    2903  
    2904      $urlbase = $CFG->wwwroot.'/pluginfile.php';
    2905      return new file_info_stored($browser, $context, $storedfile, $urlbase, $itemid, true, true, false, false);
    2906  }
    2907  
    2908  /**
    2909   * Serves the forum attachments. Implements needed access control ;-)
    2910   *
    2911   * @package  mod_forum
    2912   * @category files
    2913   * @param stdClass $course course object
    2914   * @param stdClass $cm course module object
    2915   * @param stdClass $context context object
    2916   * @param string $filearea file area
    2917   * @param array $args extra arguments
    2918   * @param bool $forcedownload whether or not force download
    2919   * @param array $options additional options affecting the file serving
    2920   * @return bool false if file not found, does not return if found - justsend the file
    2921   */
    2922  function forum_pluginfile($course, $cm, $context, $filearea, $args, $forcedownload, array $options=array()) {
    2923      global $CFG, $DB;
    2924  
    2925      if ($context->contextlevel != CONTEXT_MODULE) {
    2926          return false;
    2927      }
    2928  
    2929      require_course_login($course, true, $cm);
    2930  
    2931      $areas = forum_get_file_areas($course, $cm, $context);
    2932  
    2933      // filearea must contain a real area
    2934      if (!isset($areas[$filearea])) {
    2935          return false;
    2936      }
    2937  
    2938      $postid = (int)array_shift($args);
    2939  
    2940      if (!$post = $DB->get_record('forum_posts', array('id'=>$postid))) {
    2941          return false;
    2942      }
    2943  
    2944      if (!$discussion = $DB->get_record('forum_discussions', array('id'=>$post->discussion))) {
    2945          return false;
    2946      }
    2947  
    2948      if (!$forum = $DB->get_record('forum', array('id'=>$cm->instance))) {
    2949          return false;
    2950      }
    2951  
    2952      $fs = get_file_storage();
    2953      $relativepath = implode('/', $args);
    2954      $fullpath = "/$context->id/mod_forum/$filearea/$postid/$relativepath";
    2955      if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
    2956          return false;
    2957      }
    2958  
    2959      // Make sure groups allow this user to see this file
    2960      if ($discussion->groupid > 0) {
    2961          $groupmode = groups_get_activity_groupmode($cm, $course);
    2962          if ($groupmode == SEPARATEGROUPS) {
    2963              if (!groups_is_member($discussion->groupid) and !has_capability('moodle/site:accessallgroups', $context)) {
    2964                  return false;
    2965              }
    2966          }
    2967      }
    2968  
    2969      // Make sure we're allowed to see it...
    2970      if (!forum_user_can_see_post($forum, $discussion, $post, NULL, $cm)) {
    2971          return false;
    2972      }
    2973  
    2974      // finally send the file
    2975      send_stored_file($file, 0, 0, true, $options); // download MUST be forced - security!
    2976  }
    2977  
    2978  /**
    2979   * If successful, this function returns the name of the file
    2980   *
    2981   * @global object
    2982   * @param object $post is a full post record, including course and forum
    2983   * @param object $forum
    2984   * @param object $cm
    2985   * @param mixed $mform
    2986   * @param string $unused
    2987   * @return bool
    2988   */
    2989  function forum_add_attachment($post, $forum, $cm, $mform=null, $unused=null) {
    2990      global $DB;
    2991  
    2992      if (empty($mform)) {
    2993          return false;
    2994      }
    2995  
    2996      if (empty($post->attachments)) {
    2997          return true;   // Nothing to do
    2998      }
    2999  
    3000      $context = context_module::instance($cm->id);
    3001  
    3002      $info = file_get_draft_area_info($post->attachments);
    3003      $present = ($info['filecount']>0) ? '1' : '';
    3004      file_save_draft_area_files($post->attachments, $context->id, 'mod_forum', 'attachment', $post->id,
    3005              mod_forum_post_form::attachment_options($forum));
    3006  
    3007      $DB->set_field('forum_posts', 'attachment', $present, array('id'=>$post->id));
    3008  
    3009      return true;
    3010  }
    3011  
    3012  /**
    3013   * Add a new post in an existing discussion.
    3014   *
    3015   * @param   stdClass    $post       The post data
    3016   * @param   mixed       $mform      The submitted form
    3017   * @param   string      $unused
    3018   * @return int
    3019   */
    3020  function forum_add_new_post($post, $mform, $unused = null) {
    3021      global $USER, $DB;
    3022  
    3023      $discussion = $DB->get_record('forum_discussions', array('id' => $post->discussion));
    3024      $forum      = $DB->get_record('forum', array('id' => $discussion->forum));
    3025      $cm         = get_coursemodule_from_instance('forum', $forum->id);
    3026      $context    = context_module::instance($cm->id);
    3027      $privatereplyto = 0;
    3028  
    3029      // Check whether private replies should be enabled for this post.
    3030      if ($post->parent) {
    3031          $parent = $DB->get_record('forum_posts', array('id' => $post->parent));
    3032  
    3033          if (!empty($parent->privatereplyto)) {
    3034              throw new \coding_exception('It should not be possible to reply to a private reply');
    3035          }
    3036  
    3037          if (!empty($post->isprivatereply) && forum_user_can_reply_privately($context, $parent)) {
    3038              $privatereplyto = $parent->userid;
    3039          }
    3040      }
    3041  
    3042      $post->created    = $post->modified = time();
    3043      $post->mailed     = FORUM_MAILED_PENDING;
    3044      $post->userid     = $USER->id;
    3045      $post->privatereplyto = $privatereplyto;
    3046      $post->attachment = "";
    3047      if (!isset($post->totalscore)) {
    3048          $post->totalscore = 0;
    3049      }
    3050      if (!isset($post->mailnow)) {
    3051          $post->mailnow    = 0;
    3052      }
    3053  
    3054      \mod_forum\local\entities\post::add_message_counts($post);
    3055      $post->id = $DB->insert_record("forum_posts", $post);
    3056      $post->message = file_save_draft_area_files($post->itemid, $context->id, 'mod_forum', 'post', $post->id,
    3057              mod_forum_post_form::editor_options($context, null), $post->message);
    3058      $DB->set_field('forum_posts', 'message', $post->message, array('id'=>$post->id));
    3059      forum_add_attachment($post, $forum, $cm, $mform);
    3060  
    3061      // Update discussion modified date
    3062      $DB->set_field("forum_discussions", "timemodified", $post->modified, array("id" => $post->discussion));
    3063      $DB->set_field("forum_discussions", "usermodified", $post->userid, array("id" => $post->discussion));
    3064  
    3065      if (forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {
    3066          forum_tp_mark_post_read($post->userid, $post);
    3067      }
    3068  
    3069      if (isset($post->tags)) {
    3070          core_tag_tag::set_item_tags('mod_forum', 'forum_posts', $post->id, $context, $post->tags);
    3071      }
    3072  
    3073      // Let Moodle know that assessable content is uploaded (eg for plagiarism detection)
    3074      forum_trigger_content_uploaded_event($post, $cm, 'forum_add_new_post');
    3075  
    3076      return $post->id;
    3077  }
    3078  
    3079  /**
    3080   * Trigger post updated event.
    3081   *
    3082   * @param object $post forum post object
    3083   * @param object $discussion discussion object
    3084   * @param object $context forum context object
    3085   * @param object $forum forum object
    3086   * @since Moodle 3.8
    3087   * @return void
    3088   */
    3089  function forum_trigger_post_updated_event($post, $discussion, $context, $forum) {
    3090      global $USER;
    3091  
    3092      $params = array(
    3093          'context' => $context,
    3094          'objectid' => $post->id,
    3095          'other' => array(
    3096              'discussionid' => $discussion->id,
    3097              'forumid' => $forum->id,
    3098              'forumtype' => $forum->type,
    3099          )
    3100      );
    3101  
    3102      if ($USER->id !== $post->userid) {
    3103          $params['relateduserid'] = $post->userid;
    3104      }
    3105  
    3106      $event = \mod_forum\event\post_updated::create($params);
    3107      $event->add_record_snapshot('forum_discussions', $discussion);
    3108      $event->trigger();
    3109  }
    3110  
    3111  /**
    3112   * Update a post.
    3113   *
    3114   * @param   stdClass    $newpost    The post to update
    3115   * @param   mixed       $mform      The submitted form
    3116   * @param   string      $unused
    3117   * @return  bool
    3118   */
    3119  function forum_update_post($newpost, $mform, $unused = null) {
    3120      global $DB, $USER;
    3121  
    3122      $post       = $DB->get_record('forum_posts', array('id' => $newpost->id));
    3123      $discussion = $DB->get_record('forum_discussions', array('id' => $post->discussion));
    3124      $forum      = $DB->get_record('forum', array('id' => $discussion->forum));
    3125      $cm         = get_coursemodule_from_instance('forum', $forum->id);
    3126      $context    = context_module::instance($cm->id);
    3127  
    3128      // Allowed modifiable fields.
    3129      $modifiablefields = [
    3130          'subject',
    3131          'message',
    3132          'messageformat',
    3133          'messagetrust',
    3134          'timestart',
    3135          'timeend',
    3136          'pinned',
    3137          'attachments',
    3138      ];
    3139      foreach ($modifiablefields as $field) {
    3140          if (isset($newpost->{$field})) {
    3141              $post->{$field} = $newpost->{$field};
    3142          }
    3143      }
    3144      $post->modified = time();
    3145  
    3146      if (!$post->parent) {   // Post is a discussion starter - update discussion title and times too
    3147          $discussion->name      = $post->subject;
    3148          $discussion->timestart = $post->timestart;
    3149          $discussion->timeend   = $post->timeend;
    3150  
    3151          if (isset($post->pinned)) {
    3152              $discussion->pinned = $post->pinned;
    3153          }
    3154      }
    3155      $post->message = file_save_draft_area_files($newpost->itemid, $context->id, 'mod_forum', 'post', $post->id,
    3156              mod_forum_post_form::editor_options($context, $post->id), $post->message);
    3157      \mod_forum\local\entities\post::add_message_counts($post);
    3158      $DB->update_record('forum_posts', $post);
    3159      // Note: Discussion modified time/user are intentionally not updated, to enable them to track the latest new post.
    3160      $DB->update_record('forum_discussions', $discussion);
    3161  
    3162      forum_add_attachment($post, $forum, $cm, $mform);
    3163  
    3164      if ($forum->type == 'single' && $post->parent == '0') {
    3165          // Updating first post of single discussion type -> updating forum intro.
    3166          $forum->intro = $post->message;
    3167          $forum->timemodified = time();
    3168          $DB->update_record("forum", $forum);
    3169      }
    3170  
    3171      if (isset($newpost->tags)) {
    3172          core_tag_tag::set_item_tags('mod_forum', 'forum_posts', $post->id, $context, $newpost->tags);
    3173      }
    3174  
    3175      if (forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {
    3176          forum_tp_mark_post_read($USER->id, $post);
    3177      }
    3178  
    3179      // Let Moodle know that assessable content is uploaded (eg for plagiarism detection)
    3180      forum_trigger_content_uploaded_event($post, $cm, 'forum_update_post');
    3181  
    3182      return true;
    3183  }
    3184  
    3185  /**
    3186   * Given an object containing all the necessary data,
    3187   * create a new discussion and return the id
    3188   *
    3189   * @param object $post
    3190   * @param mixed $mform
    3191   * @param string $unused
    3192   * @param int $userid
    3193   * @return object
    3194   */
    3195  function forum_add_discussion($discussion, $mform=null, $unused=null, $userid=null) {
    3196      global $USER, $CFG, $DB;
    3197  
    3198      $timenow = isset($discussion->timenow) ? $discussion->timenow : time();
    3199  
    3200      if (is_null($userid)) {
    3201          $userid = $USER->id;
    3202      }
    3203  
    3204      // The first post is stored as a real post, and linked
    3205      // to from the discuss entry.
    3206  
    3207      $forum = $DB->get_record('forum', array('id'=>$discussion->forum));
    3208      $cm    = get_coursemodule_from_instance('forum', $forum->id);
    3209  
    3210      $post = new stdClass();
    3211      $post->discussion    = 0;
    3212      $post->parent        = 0;
    3213      $post->privatereplyto = 0;
    3214      $post->userid        = $userid;
    3215      $post->created       = $timenow;
    3216      $post->modified      = $timenow;
    3217      $post->mailed        = FORUM_MAILED_PENDING;
    3218      $post->subject       = $discussion->name;
    3219      $post->message       = $discussion->message;
    3220      $post->messageformat = $discussion->messageformat;
    3221      $post->messagetrust  = $discussion->messagetrust;
    3222      $post->attachments   = isset($discussion->attachments) ? $discussion->attachments : null;
    3223      $post->forum         = $forum->id;     // speedup
    3224      $post->course        = $forum->course; // speedup
    3225      $post->mailnow       = $discussion->mailnow;
    3226  
    3227      \mod_forum\local\entities\post::add_message_counts($post);
    3228      $post->id = $DB->insert_record("forum_posts", $post);
    3229  
    3230      // TODO: Fix the calling code so that there always is a $cm when this function is called
    3231      if (!empty($cm->id) && !empty($discussion->itemid)) {   // In "single simple discussions" this may not exist yet
    3232          $context = context_module::instance($cm->id);
    3233          $text = file_save_draft_area_files($discussion->itemid, $context->id, 'mod_forum', 'post', $post->id,
    3234                  mod_forum_post_form::editor_options($context, null), $post->message);
    3235          $DB->set_field('forum_posts', 'message', $text, array('id'=>$post->id));
    3236      }
    3237  
    3238      // Now do the main entry for the discussion, linking to this first post
    3239  
    3240      $discussion->firstpost    = $post->id;
    3241      $discussion->timemodified = $timenow;
    3242      $discussion->usermodified = $post->userid;
    3243      $discussion->userid       = $userid;
    3244      $discussion->assessed     = 0;
    3245  
    3246      $post->discussion = $DB->insert_record("forum_discussions", $discussion);
    3247  
    3248      // Finally, set the pointer on the post.
    3249      $DB->set_field("forum_posts", "discussion", $post->discussion, array("id"=>$post->id));
    3250  
    3251      if (!empty($cm->id)) {
    3252          forum_add_attachment($post, $forum, $cm, $mform, $unused);
    3253      }
    3254  
    3255      if (isset($discussion->tags)) {
    3256          core_tag_tag::set_item_tags('mod_forum', 'forum_posts', $post->id, context_module::instance($cm->id), $discussion->tags);
    3257      }
    3258  
    3259      if (forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {
    3260          forum_tp_mark_post_read($post->userid, $post);
    3261      }
    3262  
    3263      // Let Moodle know that assessable content is uploaded (eg for plagiarism detection)
    3264      if (!empty($cm->id)) {
    3265          forum_trigger_content_uploaded_event($post, $cm, 'forum_add_discussion');
    3266      }
    3267  
    3268      return $post->discussion;
    3269  }
    3270  
    3271  
    3272  /**
    3273   * Deletes a discussion and handles all associated cleanup.
    3274   *
    3275   * @global object
    3276   * @param object $discussion Discussion to delete
    3277   * @param bool $fulldelete True when deleting entire forum
    3278   * @param object $course Course
    3279   * @param object $cm Course-module
    3280   * @param object $forum Forum
    3281   * @return bool
    3282   */
    3283  function forum_delete_discussion($discussion, $fulldelete, $course, $cm, $forum) {
    3284      global $DB, $CFG;
    3285      require_once($CFG->libdir.'/completionlib.php');
    3286  
    3287      $result = true;
    3288  
    3289      if ($posts = $DB->get_records("forum_posts", array("discussion" => $discussion->id))) {
    3290          foreach ($posts as $post) {
    3291              $post->course = $discussion->course;
    3292              $post->forum  = $discussion->forum;
    3293              if (!forum_delete_post($post, 'ignore', $course, $cm, $forum, $fulldelete)) {
    3294                  $result = false;
    3295              }
    3296          }
    3297      }
    3298  
    3299      forum_tp_delete_read_records(-1, -1, $discussion->id);
    3300  
    3301      // Discussion subscriptions must be removed before discussions because of key constraints.
    3302      $DB->delete_records('forum_discussion_subs', array('discussion' => $discussion->id));
    3303      if (!$DB->delete_records("forum_discussions", array("id" => $discussion->id))) {
    3304          $result = false;
    3305      }
    3306  
    3307      // Update completion state if we are tracking completion based on number of posts
    3308      // But don't bother when deleting whole thing
    3309      if (!$fulldelete) {
    3310          $completion = new completion_info($course);
    3311          if ($completion->is_enabled($cm) == COMPLETION_TRACKING_AUTOMATIC &&
    3312             ($forum->completiondiscussions || $forum->completionreplies || $forum->completionposts)) {
    3313              $completion->update_state($cm, COMPLETION_INCOMPLETE, $discussion->userid);
    3314          }
    3315      }
    3316  
    3317      $params = array(
    3318          'objectid' => $discussion->id,
    3319          'context' => context_module::instance($cm->id),
    3320          'other' => array(
    3321              'forumid' => $forum->id,
    3322          )
    3323      );
    3324      $event = \mod_forum\event\discussion_deleted::create($params);
    3325      $event->add_record_snapshot('forum_discussions', $discussion);
    3326      $event->trigger();
    3327  
    3328      return $result;
    3329  }
    3330  
    3331  
    3332  /**
    3333   * Deletes a single forum post.
    3334   *
    3335   * @global object
    3336   * @param object $post Forum post object
    3337   * @param mixed $children Whether to delete children. If false, returns false
    3338   *   if there are any children (without deleting the post). If true,
    3339   *   recursively deletes all children. If set to special value 'ignore', deletes
    3340   *   post regardless of children (this is for use only when deleting all posts
    3341   *   in a disussion).
    3342   * @param object $course Course
    3343   * @param object $cm Course-module
    3344   * @param object $forum Forum
    3345   * @param bool $skipcompletion True to skip updating completion state if it
    3346   *   would otherwise be updated, i.e. when deleting entire forum anyway.
    3347   * @return bool
    3348   */
    3349  function forum_delete_post($post, $children, $course, $cm, $forum, $skipcompletion=false) {
    3350      global $DB, $CFG, $USER;
    3351      require_once($CFG->libdir.'/completionlib.php');
    3352  
    3353      $context = context_module::instance($cm->id);
    3354  
    3355      if ($children !== 'ignore' && ($childposts = $DB->get_records('forum_posts', array('parent'=>$post->id)))) {
    3356         if ($children) {
    3357             foreach ($childposts as $childpost) {
    3358                 forum_delete_post($childpost, true, $course, $cm, $forum, $skipcompletion);
    3359             }
    3360         } else {
    3361             return false;
    3362         }
    3363      }
    3364  
    3365      // Delete ratings.
    3366      require_once($CFG->dirroot.'/rating/lib.php');
    3367      $delopt = new stdClass;
    3368      $delopt->contextid = $context->id;
    3369      $delopt->component = 'mod_forum';
    3370      $delopt->ratingarea = 'post';
    3371      $delopt->itemid = $post->id;
    3372      $rm = new rating_manager();
    3373      $rm->delete_ratings($delopt);
    3374  
    3375      // Delete attachments.
    3376      $fs = get_file_storage();
    3377      $fs->delete_area_files($context->id, 'mod_forum', 'attachment', $post->id);
    3378      $fs->delete_area_files($context->id, 'mod_forum', 'post', $post->id);
    3379  
    3380      // Delete cached RSS feeds.
    3381      if (!empty($CFG->enablerssfeeds)) {
    3382          require_once($CFG->dirroot.'/mod/forum/rsslib.php');
    3383          forum_rss_delete_file($forum);
    3384      }
    3385  
    3386      if ($DB->delete_records("forum_posts", array("id" => $post->id))) {
    3387  
    3388          forum_tp_delete_read_records(-1, $post->id);
    3389  
    3390      // Just in case we are deleting the last post
    3391          forum_discussion_update_last_post($post->discussion);
    3392  
    3393          // Update completion state if we are tracking completion based on number of posts
    3394          // But don't bother when deleting whole thing
    3395  
    3396          if (!$skipcompletion) {
    3397              $completion = new completion_info($course);
    3398              if ($completion->is_enabled($cm) == COMPLETION_TRACKING_AUTOMATIC &&
    3399                 ($forum->completiondiscussions || $forum->completionreplies || $forum->completionposts)) {
    3400                  $completion->update_state($cm, COMPLETION_INCOMPLETE, $post->userid);
    3401              }
    3402          }
    3403  
    3404          $params = array(
    3405              'context' => $context,
    3406              'objectid' => $post->id,
    3407              'other' => array(
    3408                  'discussionid' => $post->discussion,
    3409                  'forumid' => $forum->id,
    3410                  'forumtype' => $forum->type,
    3411              )
    3412          );
    3413          $post->deleted = 1;
    3414          if ($post->userid !== $USER->id) {
    3415              $params['relateduserid'] = $post->userid;
    3416          }
    3417          $event = \mod_forum\event\post_deleted::create($params);
    3418          $event->add_record_snapshot('forum_posts', $post);
    3419          $event->trigger();
    3420  
    3421          return true;
    3422      }
    3423      return false;
    3424  }
    3425  
    3426  /**
    3427   * Sends post content to plagiarism plugin
    3428   * @param object $post Forum post object
    3429   * @param object $cm Course-module
    3430   * @param string $name
    3431   * @return bool
    3432  */
    3433  function forum_trigger_content_uploaded_event($post, $cm, $name) {
    3434      $context = context_module::instance($cm->id);
    3435      $fs = get_file_storage();
    3436      $files = $fs->get_area_files($context->id, 'mod_forum', 'attachment', $post->id, "timemodified", false);
    3437      $params = array(
    3438          'context' => $context,
    3439          'objectid' => $post->id,
    3440          'other' => array(
    3441              'content' => $post->message,
    3442              'pathnamehashes' => array_keys($files),
    3443              'discussionid' => $post->discussion,
    3444              'triggeredfrom' => $name,
    3445          )
    3446      );
    3447      $event = \mod_forum\event\assessable_uploaded::create($params);
    3448      $event->trigger();
    3449      return true;
    3450  }
    3451  
    3452  /**
    3453   * Given a new post, subscribes or unsubscribes as appropriate.
    3454   * Returns some text which describes what happened.
    3455   *
    3456   * @param object $fromform The submitted form
    3457   * @param stdClass $forum The forum record
    3458   * @param stdClass $discussion The forum discussion record
    3459   * @return string
    3460   */
    3461  function forum_post_subscription($fromform, $forum, $discussion) {
    3462      global $USER;
    3463  
    3464      if (\mod_forum\subscriptions::is_forcesubscribed($forum)) {
    3465          return "";
    3466      } else if (\mod_forum\subscriptions::subscription_disabled($forum)) {
    3467          $subscribed = \mod_forum\subscriptions::is_subscribed($USER->id, $forum);
    3468          if ($subscribed && !has_capability('moodle/course:manageactivities', context_course::instance($forum->course), $USER->id)) {
    3469              // This user should not be subscribed to the forum.
    3470              \mod_forum\subscriptions::unsubscribe_user($USER->id, $forum);
    3471          }
    3472          return "";
    3473      }
    3474  
    3475      $info = new stdClass();
    3476      $info->name  = fullname($USER);
    3477      $info->discussion = format_string($discussion->name);
    3478      $info->forum = format_string($forum->name);
    3479  
    3480      if (isset($fromform->discussionsubscribe) && $fromform->discussionsubscribe) {
    3481          if ($result = \mod_forum\subscriptions::subscribe_user_to_discussion($USER->id, $discussion)) {
    3482              return html_writer::tag('p', get_string('discussionnowsubscribed', 'forum', $info));
    3483          }
    3484      } else {
    3485          if ($result = \mod_forum\subscriptions::unsubscribe_user_from_discussion($USER->id, $discussion)) {
    3486              return html_writer::tag('p', get_string('discussionnownotsubscribed', 'forum', $info));
    3487          }
    3488      }
    3489  
    3490      return '';
    3491  }
    3492  
    3493  /**
    3494   * Generate and return the subscribe or unsubscribe link for a forum.
    3495   *
    3496   * @param object $forum the forum. Fields used are $forum->id and $forum->forcesubscribe.
    3497   * @param object $context the context object for this forum.
    3498   * @param array $messages text used for the link in its various states
    3499   *      (subscribed, unsubscribed, forcesubscribed or cantsubscribe).
    3500   *      Any strings not passed in are taken from the $defaultmessages array
    3501   *      at the top of the function.
    3502   * @param bool $cantaccessagroup
    3503   * @param bool $unused1
    3504   * @param bool $backtoindex
    3505   * @param array $unused2
    3506   * @return string
    3507   */
    3508  function forum_get_subscribe_link($forum, $context, $messages = array(), $cantaccessagroup = false, $unused1 = true,
    3509      $backtoindex = false, $unused2 = null) {
    3510      global $CFG, $USER, $PAGE, $OUTPUT;
    3511      $defaultmessages = array(
    3512          'subscribed' => get_string('unsubscribe', 'forum'),
    3513          'unsubscribed' => get_string('subscribe', 'forum'),
    3514          'cantaccessgroup' => get_string('no'),
    3515          'forcesubscribed' => get_string('everyoneissubscribed', 'forum'),
    3516          'cantsubscribe' => get_string('disallowsubscribe','forum')
    3517      );
    3518      $messages = $messages + $defaultmessages;
    3519  
    3520      if (\mod_forum\subscriptions::is_forcesubscribed($forum)) {
    3521          return $messages['forcesubscribed'];
    3522      } else if (\mod_forum\subscriptions::subscription_disabled($forum) &&
    3523              !has_capability('mod/forum:managesubscriptions', $context)) {
    3524          return $messages['cantsubscribe'];
    3525      } else if ($cantaccessagroup) {
    3526          return $messages['cantaccessgroup'];
    3527      } else {
    3528          if (!is_enrolled($context, $USER, '', true)) {
    3529              return '';
    3530          }
    3531  
    3532          $subscribed = \mod_forum\subscriptions::is_subscribed($USER->id, $forum);
    3533          if ($subscribed) {
    3534              $linktext = $messages['subscribed'];
    3535              $linktitle = get_string('subscribestop', 'forum');
    3536          } else {
    3537              $linktext = $messages['unsubscribed'];
    3538              $linktitle = get_string('subscribestart', 'forum');
    3539          }
    3540  
    3541          $options = array();
    3542          if ($backtoindex) {
    3543              $backtoindexlink = '&amp;backtoindex=1';
    3544              $options['backtoindex'] = 1;
    3545          } else {
    3546              $backtoindexlink = '';
    3547          }
    3548  
    3549          $options['id'] = $forum->id;
    3550          $options['sesskey'] = sesskey();
    3551          $url = new moodle_url('/mod/forum/subscribe.php', $options);
    3552          return $OUTPUT->single_button($url, $linktext, 'get', array('title' => $linktitle));
    3553      }
    3554  }
    3555  
    3556  /**
    3557   * Returns true if user created new discussion already.
    3558   *
    3559   * @param int $forumid  The forum to check for postings
    3560   * @param int $userid   The user to check for postings
    3561   * @param int $groupid  The group to restrict the check to
    3562   * @return bool
    3563   */
    3564  function forum_user_has_posted_discussion($forumid, $userid, $groupid = null) {
    3565      global $CFG, $DB;
    3566  
    3567      $sql = "SELECT 'x'
    3568                FROM {forum_discussions} d, {forum_posts} p
    3569               WHERE d.forum = ? AND p.discussion = d.id AND p.parent = 0 AND p.userid = ?";
    3570  
    3571      $params = [$forumid, $userid];
    3572  
    3573      if ($groupid) {
    3574          $sql .= " AND d.groupid = ?";
    3575          $params[] = $groupid;
    3576      }
    3577  
    3578      return $DB->record_exists_sql($sql, $params);
    3579  }
    3580  
    3581  /**
    3582   * @global object
    3583   * @global object
    3584   * @param int $forumid
    3585   * @param int $userid
    3586   * @return array
    3587   */
    3588  function forum_discussions_user_has_posted_in($forumid, $userid) {
    3589      global $CFG, $DB;
    3590  
    3591      $haspostedsql = "SELECT d.id AS id,
    3592                              d.*
    3593                         FROM {forum_posts} p,
    3594                              {forum_discussions} d
    3595                        WHERE p.discussion = d.id
    3596                          AND d.forum = ?
    3597                          AND p.userid = ?";
    3598  
    3599      return $DB->get_records_sql($haspostedsql, array($forumid, $userid));
    3600  }
    3601  
    3602  /**
    3603   * @global object
    3604   * @global object
    3605   * @param int $forumid
    3606   * @param int $did
    3607   * @param int $userid
    3608   * @return bool
    3609   */
    3610  function forum_user_has_posted($forumid, $did, $userid) {
    3611      global $DB;
    3612  
    3613      if (empty($did)) {
    3614          // posted in any forum discussion?
    3615          $sql = "SELECT 'x'
    3616                    FROM {forum_posts} p
    3617                    JOIN {forum_discussions} d ON d.id = p.discussion
    3618                   WHERE p.userid = :userid AND d.forum = :forumid";
    3619          return $DB->record_exists_sql($sql, array('forumid'=>$forumid,'userid'=>$userid));
    3620      } else {
    3621          return $DB->record_exists('forum_posts', array('discussion'=>$did,'userid'=>$userid));
    3622      }
    3623  }
    3624  
    3625  /**
    3626   * Returns creation time of the first user's post in given discussion
    3627   * @global object $DB
    3628   * @param int $did Discussion id
    3629   * @param int $userid User id
    3630   * @return int|bool post creation time stamp or return false
    3631   */
    3632  function forum_get_user_posted_time($did, $userid) {
    3633      global $DB;
    3634  
    3635      $posttime = $DB->get_field('forum_posts', 'MIN(created)', array('userid'=>$userid, 'discussion'=>$did));
    3636      if (empty($posttime)) {
    3637          return false;
    3638      }
    3639      return $posttime;
    3640  }
    3641  
    3642  /**
    3643   * @global object
    3644   * @param object $forum
    3645   * @param object $currentgroup
    3646   * @param int $unused
    3647   * @param object $cm
    3648   * @param object $context
    3649   * @return bool
    3650   */
    3651  function forum_user_can_post_discussion($forum, $currentgroup=null, $unused=-1, $cm=NULL, $context=NULL) {
    3652  // $forum is an object
    3653      global $USER;
    3654  
    3655      // shortcut - guest and not-logged-in users can not post
    3656      if (isguestuser() or !isloggedin()) {
    3657          return false;
    3658      }
    3659  
    3660      if (!$cm) {
    3661          debugging('missing cm', DEBUG_DEVELOPER);
    3662          if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
    3663<