mod/chat/lib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Library of functions and constants for module chat
  19  *
  20  * @package   mod_chat
  21  * @copyright 1999 onwards Martin Dougiamas  {@link http://moodle.com}
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 require_once($CFG->dirroot.'/calendar/lib.php');
  26
  27 // The HTML head for the message window to start with (<!-- nix --> is used to get some browsers starting with output.
  28 global $CHAT_HTMLHEAD;
  29 $CHAT_HTMLHEAD = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\" \"http://www.w3.org/TR/REC-html40/loose.dtd\"><html><head></head>\n<body>\n\n".padding(200);
  30
  31 // The HTML head for the message window to start with (with js scrolling).
  32 global $CHAT_HTMLHEAD_JS;
  33 $CHAT_HTMLHEAD_JS = <<<EOD
  34 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
  35 <html><head><script type="text/javascript">
  36 //<![CDATA[
  37 function move() {
  38     if (scroll_active)
  39         window.scroll(1,400000);
  40     window.setTimeout("move()",100);
  41 }
  42 var scroll_active = true;
  43 move();
  44 //]]>
  45 </script>
  46 </head>
  47 <body onBlur="scroll_active = true" onFocus="scroll_active = false">
  48 EOD;
  49 global $CHAT_HTMLHEAD_JS;
  50 $CHAT_HTMLHEAD_JS .= padding(200);
  51
  52 // The HTML code for standard empty pages (e.g. if a user was kicked out).
  53 global $CHAT_HTMLHEAD_OUT;
  54 $CHAT_HTMLHEAD_OUT = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\" \"http://www.w3.org/TR/REC-html40/loose.dtd\"><html><head><title>You are out!</title></head><body></body></html>";
  55
  56 // The HTML head for the message input page.
  57 global $CHAT_HTMLHEAD_MSGINPUT;
  58 $CHAT_HTMLHEAD_MSGINPUT = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\" \"http://www.w3.org/TR/REC-html40/loose.dtd\"><html><head><title>Message Input</title></head><body>";
  59
  60 // The HTML code for the message input page, with JavaScript.
  61 global $CHAT_HTMLHEAD_MSGINPUT_JS;
  62 $CHAT_HTMLHEAD_MSGINPUT_JS = <<<EOD
  63 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
  64 <html>
  65     <head><title>Message Input</title>
  66     <script type="text/javascript">
  67     //<![CDATA[
  68     scroll_active = true;
  69     function empty_field_and_submit() {
  70         document.fdummy.arsc_message.value=document.f.arsc_message.value;
  71         document.fdummy.submit();
  72         document.f.arsc_message.focus();
  73         document.f.arsc_message.select();
  74         return false;
  75     }
  76     //]]>
  77     </script>
  78     </head><body OnLoad="document.f.arsc_message.focus();document.f.arsc_message.select();">;
  79 EOD;
  80
  81 // Dummy data that gets output to the browser as needed, in order to make it show output.
  82 global $CHAT_DUMMY_DATA;
  83 $CHAT_DUMMY_DATA = padding(200);
  84
  85 /**
  86  * @param int $n
  87  * @return string
  88  */
  89 function padding($n) {
  90     $str = '';
  91     for ($i = 0; $i < $n; $i++) {
  92         $str .= "<!-- nix -->\n";
  93     }
  94     return $str;
  95 }
  96
  97 /**
  98  * Given an object containing all the necessary data,
  99  * (defined by the form in mod_form.php) this function
 100  * will create a new instance and return the id number
 101  * of the new instance.
 102  *
 103  * @global object
 104  * @param object $chat
 105  * @return int
 106  */
 107 function chat_add_instance($chat) {
 108     global $DB;
 109
 110     $chat->timemodified = time();
 111
 112     $returnid = $DB->insert_record("chat", $chat);
 113
 114     $event = new stdClass();
 115     $event->name        = $chat->name;
 116     $event->description = format_module_intro('chat', $chat, $chat->coursemodule);
 117     $event->courseid    = $chat->course;
 118     $event->groupid     = 0;
 119     $event->userid      = 0;
 120     $event->modulename  = 'chat';
 121     $event->instance    = $returnid;
 122     $event->eventtype   = 'chattime';
 123     $event->timestart   = $chat->chattime;
 124     $event->timeduration = 0;
 125
 126     calendar_event::create($event);
 127
 128     return $returnid;
 129 }
 130
 131 /**
 132  * Given an object containing all the necessary data,
 133  * (defined by the form in mod_form.php) this function
 134  * will update an existing instance with new data.
 135  *
 136  * @global object
 137  * @param object $chat
 138  * @return bool
 139  */
 140 function chat_update_instance($chat) {
 141     global $DB;
 142
 143     $chat->timemodified = time();
 144     $chat->id = $chat->instance;
 145
 146     $DB->update_record("chat", $chat);
 147
 148     $event = new stdClass();
 149
 150     if ($event->id = $DB->get_field('event', 'id', array('modulename' => 'chat', 'instance' => $chat->id))) {
 151
 152         $event->name        = $chat->name;
 153         $event->description = format_module_intro('chat', $chat, $chat->coursemodule);
 154         $event->timestart   = $chat->chattime;
 155
 156         $calendarevent = calendar_event::load($event->id);
 157         $calendarevent->update($event);
 158     }
 159
 160     return true;
 161 }
 162
 163 /**
 164  * Given an ID of an instance of this module,
 165  * this function will permanently delete the instance
 166  * and any data that depends on it.
 167  *
 168  * @global object
 169  * @param int $id
 170  * @return bool
 171  */
 172 function chat_delete_instance($id) {
 173     global $DB;
 174
 175     if (! $chat = $DB->get_record('chat', array('id' => $id))) {
 176         return false;
 177     }
 178
 179     $result = true;
 180
 181     // Delete any dependent records here.
 182
 183     if (! $DB->delete_records('chat', array('id' => $chat->id))) {
 184         $result = false;
 185     }
 186     if (! $DB->delete_records('chat_messages', array('chatid' => $chat->id))) {
 187         $result = false;
 188     }
 189     if (! $DB->delete_records('chat_messages_current', array('chatid' => $chat->id))) {
 190         $result = false;
 191     }
 192     if (! $DB->delete_records('chat_users', array('chatid' => $chat->id))) {
 193         $result = false;
 194     }
 195
 196     if (! $DB->delete_records('event', array('modulename' => 'chat', 'instance' => $chat->id))) {
 197         $result = false;
 198     }
 199
 200     return $result;
 201 }
 202
 203 /**
 204  * Given a course and a date, prints a summary of all chat rooms past and present
 205  * This function is called from block_recent_activity
 206  *
 207  * @global object
 208  * @global object
 209  * @global object
 210  * @param object $course
 211  * @param bool $viewfullnames
 212  * @param int|string $timestart Timestamp
 213  * @return bool
 214  */
 215 function chat_print_recent_activity($course, $viewfullnames, $timestart) {
 216     global $CFG, $USER, $DB, $OUTPUT;
 217
 218     // This is approximate only, but it is really fast.
 219     $timeout = $CFG->chat_old_ping * 10;
 220
 221     if (!$mcms = $DB->get_records_sql("SELECT cm.id, MAX(chm.timestamp) AS lasttime
 222                                          FROM {course_modules} cm
 223                                          JOIN {modules} md        ON md.id = cm.module
 224                                          JOIN {chat} ch           ON ch.id = cm.instance
 225                                          JOIN {chat_messages} chm ON chm.chatid = ch.id
 226                                         WHERE chm.timestamp > ? AND ch.course = ? AND md.name = 'chat'
 227                                      GROUP BY cm.id
 228                                      ORDER BY lasttime ASC", array($timestart, $course->id))) {
 229          return false;
 230     }
 231
 232     $past     = array();
 233     $current  = array();
 234     $modinfo = get_fast_modinfo($course); // Reference needed because we might load the groups.
 235
 236     foreach ($mcms as $cmid => $mcm) {
 237         if (!array_key_exists($cmid, $modinfo->cms)) {
 238             continue;
 239         }
 240         $cm = $modinfo->cms[$cmid];
 241         if (!$modinfo->cms[$cm->id]->uservisible) {
 242             continue;
 243         }
 244
 245         if (groups_get_activity_groupmode($cm) != SEPARATEGROUPS
 246          or has_capability('moodle/site:accessallgroups', context_module::instance($cm->id))) {
 247             if ($timeout > time() - $mcm->lasttime) {
 248                 $current[] = $cm;
 249             } else {
 250                 $past[] = $cm;
 251             }
 252
 253             continue;
 254         }
 255
 256         // Verify groups in separate mode.
 257         if (!$mygroupids = $modinfo->get_groups($cm->groupingid)) {
 258             continue;
 259         }
 260
 261         // Ok, last post was not for my group - we have to query db to get last message from one of my groups.
 262         // The only minor problem is that the order will not be correct.
 263         $mygroupids = implode(',', $mygroupids);
 264
 265         if (!$mcm = $DB->get_record_sql("SELECT cm.id, MAX(chm.timestamp) AS lasttime
 266                                            FROM {course_modules} cm
 267                                            JOIN {chat} ch           ON ch.id = cm.instance
 268                                            JOIN {chat_messages_current} chm ON chm.chatid = ch.id
 269                                           WHERE chm.timestamp > ? AND cm.id = ? AND
 270                                                 (chm.groupid IN ($mygroupids) OR chm.groupid = 0)
 271                                        GROUP BY cm.id", array($timestart, $cm->id))) {
 272              continue;
 273         }
 274
 275         $mcms[$cmid]->lasttime = $mcm->lasttime;
 276         if ($timeout > time() - $mcm->lasttime) {
 277             $current[] = $cm;
 278         } else {
 279             $past[] = $cm;
 280         }
 281     }
 282
 283     if (!$past and !$current) {
 284         return false;
 285     }
 286
 287     $strftimerecent = get_string('strftimerecent');
 288
 289     if ($past) {
 290         echo $OUTPUT->heading(get_string("pastchats", 'chat').':', 3);
 291
 292         foreach ($past as $cm) {
 293             $link = $CFG->wwwroot.'/mod/chat/view.php?id='.$cm->id;
 294             $date = userdate($mcms[$cm->id]->lasttime, $strftimerecent);
 295             echo '<div class="head"><div class="date">'.$date.'</div></div>';
 296             echo '<div class="info"><a href="'.$link.'">'.format_string($cm->name, true).'</a></div>';
 297         }
 298     }
 299
 300     if ($current) {
 301         echo $OUTPUT->heading(get_string("currentchats", 'chat').':', 3);
 302
 303         $oldest = floor((time() - $CFG->chat_old_ping) / 10) * 10;  // Better db caching.
 304
 305         $timeold    = time() - $CFG->chat_old_ping;
 306         $timeold    = floor($timeold / 10) * 10;  // Better db caching.
 307         $timeoldext = time() - ($CFG->chat_old_ping * 10); // JSless gui_basic needs much longer timeouts.
 308         $timeoldext = floor($timeoldext / 10) * 10;  // Better db caching.
 309
 310         $params = array('timeold' => $timeold, 'timeoldext' => $timeoldext, 'cmid' => $cm->id);
 311
 312         $timeout = "AND ((chu.version<>'basic' AND chu.lastping>:timeold) OR (chu.version='basic' AND chu.lastping>:timeoldext))";
 313
 314         foreach ($current as $cm) {
 315             // Count users first.
 316             $mygroupids = $modinfo->groups[$cm->groupingid];
 317             if (!empty($mygroupids)) {
 318                 list($subquery, $subparams) = $DB->get_in_or_equal($mygroupids, SQL_PARAMS_NAMED, 'gid');
 319                 $params += $subparams;
 320                 $groupselect = "AND (chu.groupid $subquery OR chu.groupid = 0)";
 321             } else {
 322                 $groupselect = "";
 323             }
 324
 325             $userfields = user_picture::fields('u');
 326             if (!$users = $DB->get_records_sql("SELECT $userfields
 327                                                   FROM {course_modules} cm
 328                                                   JOIN {chat} ch        ON ch.id = cm.instance
 329                                                   JOIN {chat_users} chu ON chu.chatid = ch.id
 330                                                   JOIN {user} u         ON u.id = chu.userid
 331                                                  WHERE cm.id = :cmid $timeout $groupselect
 332                                               GROUP BY $userfields", $params)) {
 333             }
 334
 335             $link = $CFG->wwwroot.'/mod/chat/view.php?id='.$cm->id;
 336             $date = userdate($mcms[$cm->id]->lasttime, $strftimerecent);
 337
 338             echo '<div class="head"><div class="date">'.$date.'</div></div>';
 339             echo '<div class="info"><a href="'.$link.'">'.format_string($cm->name, true).'</a></div>';
 340             echo '<div class="userlist">';
 341             if ($users) {
 342                 echo '<ul>';
 343                 foreach ($users as $user) {
 344                     echo '<li>'.fullname($user, $viewfullnames).'</li>';
 345                 }
 346                 echo '</ul>';
 347             }
 348             echo '</div>';
 349         }
 350     }
 351
 352     return true;
 353 }
 354
 355 /**
 356  * Function to be run periodically according to the moodle cron
 357  * This function searches for things that need to be done, such
 358  * as sending out mail, toggling flags etc ...
 359  *
 360  * @global object
 361  * @return bool
 362  */
 363 function chat_cron () {
 364     global $DB;
 365
 366     chat_update_chat_times();
 367
 368     chat_delete_old_users();
 369
 370     // Delete old messages with a single SQL query.
 371     $subselect = "SELECT c.keepdays
 372                     FROM {chat} c
 373                    WHERE c.id = {chat_messages}.chatid";
 374
 375     $sql = "DELETE
 376               FROM {chat_messages}
 377              WHERE ($subselect) > 0 AND timestamp < ( ".time()." -($subselect) * 24 * 3600)";
 378
 379     $DB->execute($sql);
 380
 381     $sql = "DELETE
 382               FROM {chat_messages_current}
 383              WHERE timestamp < ( ".time()." - 8 * 3600)";
 384
 385     $DB->execute($sql);
 386
 387     return true;
 388 }
 389
 390 /**
 391  * This standard function will check all instances of this module
 392  * and make sure there are up-to-date events created for each of them.
 393  * If courseid = 0, then every chat event in the site is checked, else
 394  * only chat events belonging to the course specified are checked.
 395  * This function is used, in its new format, by restore_refresh_events()
 396  *
 397  * @global object
 398  * @param int $courseid
 399  * @return bool
 400  */
 401 function chat_refresh_events($courseid = 0) {
 402     global $DB;
 403
 404     if ($courseid) {
 405         if (! $chats = $DB->get_records("chat", array("course" => $courseid))) {
 406             return true;
 407         }
 408     } else {
 409         if (! $chats = $DB->get_records("chat")) {
 410             return true;
 411         }
 412     }
 413     $moduleid = $DB->get_field('modules', 'id', array('name' => 'chat'));
 414
 415     foreach ($chats as $chat) {
 416         $cm = get_coursemodule_from_id('chat', $chat->id);
 417         $event = new stdClass();
 418         $event->name        = $chat->name;
 419         $event->description = format_module_intro('chat', $chat, $cm->id);
 420         $event->timestart   = $chat->chattime;
 421
 422         if ($event->id = $DB->get_field('event', 'id', array('modulename' => 'chat', 'instance' => $chat->id))) {
 423             $calendarevent = calendar_event::load($event->id);
 424             $calendarevent->update($event);
 425         } else {
 426             $event->courseid    = $chat->course;
 427             $event->groupid     = 0;
 428             $event->userid      = 0;
 429             $event->modulename  = 'chat';
 430             $event->instance    = $chat->id;
 431             $event->eventtype   = 'chattime';
 432             $event->timeduration = 0;
 433             $event->visible = $DB->get_field('course_modules', 'visible', array('module' => $moduleid, 'instance' => $chat->id));
 434
 435             calendar_event::create($event);
 436         }
 437     }
 438     return true;
 439 }
 440
 441 // Functions that require some SQL.
 442
 443 /**
 444  * @global object
 445  * @param int $chatid
 446  * @param int $groupid
 447  * @param int $groupingid
 448  * @return array
 449  */
 450 function chat_get_users($chatid, $groupid=0, $groupingid=0) {
 451     global $DB;
 452
 453     $params = array('chatid' => $chatid, 'groupid' => $groupid, 'groupingid' => $groupingid);
 454
 455     if ($groupid) {
 456         $groupselect = " AND (c.groupid=:groupid OR c.groupid='0')";
 457     } else {
 458         $groupselect = "";
 459     }
 460
 461     if (!empty($groupingid)) {
 462         $groupingjoin = "JOIN {groups_members} gm ON u.id = gm.userid
 463                          JOIN {groupings_groups} gg ON gm.groupid = gg.groupid AND gg.groupingid = :groupingid ";
 464
 465     } else {
 466         $groupingjoin = '';
 467     }
 468
 469     $ufields = user_picture::fields('u');
 470     return $DB->get_records_sql("SELECT DISTINCT $ufields, c.lastmessageping, c.firstping
 471                                    FROM {chat_users} c
 472                                    JOIN {user} u ON u.id = c.userid $groupingjoin
 473                                   WHERE c.chatid = :chatid $groupselect
 474                                ORDER BY c.firstping ASC", $params);
 475 }
 476
 477 /**
 478  * @global object
 479  * @param int $chatid
 480  * @param int $groupid
 481  * @return array
 482  */
 483 function chat_get_latest_message($chatid, $groupid=0) {
 484     global $DB;
 485
 486     $params = array('chatid' => $chatid, 'groupid' => $groupid);
 487
 488     if ($groupid) {
 489         $groupselect = "AND (groupid=:groupid OR groupid=0)";
 490     } else {
 491         $groupselect = "";
 492     }
 493
 494     $sql = "SELECT *
 495         FROM {chat_messages_current} WHERE chatid = :chatid $groupselect
 496         ORDER BY timestamp DESC";
 497
 498     // Return the lastest one message.
 499     return $DB->get_record_sql($sql, $params, true);
 500 }
 501
 502 /**
 503  * login if not already logged in
 504  *
 505  * @global object
 506  * @global object
 507  * @param int $chatid
 508  * @param string $version
 509  * @param int $groupid
 510  * @param object $course
 511  * @return bool|int Returns the chat users sid or false
 512  */
 513 function chat_login_user($chatid, $version, $groupid, $course) {
 514     global $USER, $DB;
 515
 516     if (($version != 'sockets') and $chatuser = $DB->get_record('chat_users', array('chatid' => $chatid,
 517                                                                                     'userid' => $USER->id,
 518                                                                                     'groupid' => $groupid))) {
 519         // This will update logged user information.
 520         $chatuser->version  = $version;
 521         $chatuser->ip       = $USER->lastip;
 522         $chatuser->lastping = time();
 523         $chatuser->lang     = current_language();
 524
 525         // Sometimes $USER->lastip is not setup properly during login.
 526         // Update with current value if possible or provide a dummy value for the db.
 527         if (empty($chatuser->ip)) {
 528             $chatuser->ip = getremoteaddr();
 529         }
 530
 531         if (($chatuser->course != $course->id) or ($chatuser->userid != $USER->id)) {
 532             return false;
 533         }
 534         $DB->update_record('chat_users', $chatuser);
 535
 536     } else {
 537         $chatuser = new stdClass();
 538         $chatuser->chatid   = $chatid;
 539         $chatuser->userid   = $USER->id;
 540         $chatuser->groupid  = $groupid;
 541         $chatuser->version  = $version;
 542         $chatuser->ip       = $USER->lastip;
 543         $chatuser->lastping = $chatuser->firstping = $chatuser->lastmessageping = time();
 544         $chatuser->sid      = random_string(32);
 545         $chatuser->course   = $course->id; // Caching - needed for current_language too.
 546         $chatuser->lang     = current_language(); // Caching - to resource intensive to find out later.
 547
 548         // Sometimes $USER->lastip is not setup properly during login.
 549         // Update with current value if possible or provide a dummy value for the db.
 550         if (empty($chatuser->ip)) {
 551             $chatuser->ip = getremoteaddr();
 552         }
 553
 554         $DB->insert_record('chat_users', $chatuser);
 555
 556         if ($version == 'sockets') {
 557             // Do not send 'enter' message, chatd will do it.
 558         } else {
 559             chat_send_chatmessage($chatuser, 'enter', true);
 560         }
 561     }
 562
 563     return $chatuser->sid;
 564 }
 565
 566 /**
 567  * Delete the old and in the way
 568  *
 569  * @global object
 570  * @global object
 571  */
 572 function chat_delete_old_users() {
 573     // Delete the old and in the way.
 574     global $CFG, $DB;
 575
 576     $timeold = time() - $CFG->chat_old_ping;
 577     $timeoldext = time() - ($CFG->chat_old_ping * 10); // JSless gui_basic needs much longer timeouts.
 578
 579     $query = "(version<>'basic' AND lastping<?) OR (version='basic' AND lastping<?)";
 580     $params = array($timeold, $timeoldext);
 581
 582     if ($oldusers = $DB->get_records_select('chat_users', $query, $params) ) {
 583         $DB->delete_records_select('chat_users', $query, $params);
 584         foreach ($oldusers as $olduser) {
 585             chat_send_chatmessage($olduser, 'exit', true);
 586         }
 587     }
 588 }
 589
 590 /**
 591  * Updates chat records so that the next chat time is correct
 592  *
 593  * @global object
 594  * @param int $chatid
 595  * @return void
 596  */
 597 function chat_update_chat_times($chatid=0) {
 598     // Updates chat records so that the next chat time is correct.
 599     global $DB;
 600
 601     $timenow = time();
 602
 603     $params = array('timenow' => $timenow, 'chatid' => $chatid);
 604
 605     if ($chatid) {
 606         if (!$chats[] = $DB->get_record_select("chat", "id = :chatid AND chattime <= :timenow AND schedule > 0", $params)) {
 607             return;
 608         }
 609     } else {
 610         if (!$chats = $DB->get_records_select("chat", "chattime <= :timenow AND schedule > 0", $params)) {
 611             return;
 612         }
 613     }
 614
 615     foreach ($chats as $chat) {
 616         switch ($chat->schedule) {
 617             case 1: // Single event - turn off schedule and disable.
 618                 $chat->chattime = 0;
 619                 $chat->schedule = 0;
 620                 break;
 621             case 2: // Repeat daily.
 622                 while ($chat->chattime <= $timenow) {
 623                     $chat->chattime += 24 * 3600;
 624                 }
 625                 break;
 626             case 3: // Repeat weekly.
 627                 while ($chat->chattime <= $timenow) {
 628                     $chat->chattime += 7 * 24 * 3600;
 629                 }
 630                 break;
 631         }
 632         $DB->update_record("chat", $chat);
 633
 634         $event = new stdClass(); // Update calendar too.
 635
 636         $cond = "modulename='chat' AND instance = :chatid AND timestart <> :chattime";
 637         $params = array('chattime' => $chat->chattime, 'chatid' => $chatid);
 638
 639         if ($event->id = $DB->get_field_select('event', 'id', $cond, $params)) {
 640             $event->timestart   = $chat->chattime;
 641             $calendarevent = calendar_event::load($event->id);
 642             $calendarevent->update($event, false);
 643         }
 644     }
 645 }
 646
 647 /**
 648  * Send a message on the chat.
 649  *
 650  * @param object $chatuser The chat user record.
 651  * @param string $messagetext The message to be sent.
 652  * @param bool $system False for non-system messages, true for system messages.
 653  * @param object $cm The course module object, pass it to save a database query when we trigger the event.
 654  * @return int The message ID.
 655  * @since Moodle 2.6
 656  */
 657 function chat_send_chatmessage($chatuser, $messagetext, $system = false, $cm = null) {
 658     global $DB;
 659
 660     $message = new stdClass();
 661     $message->chatid    = $chatuser->chatid;
 662     $message->userid    = $chatuser->userid;
 663     $message->groupid   = $chatuser->groupid;
 664     $message->message   = $messagetext;
 665     $message->system    = $system ? 1 : 0;
 666     $message->timestamp = time();
 667
 668     $messageid = $DB->insert_record('chat_messages', $message);
 669     $DB->insert_record('chat_messages_current', $message);
 670     $message->id = $messageid;
 671
 672     if (!$system) {
 673
 674         if (empty($cm)) {
 675             $cm = get_coursemodule_from_instance('chat', $chatuser->chatid, $chatuser->course);
 676         }
 677
 678         $params = array(
 679             'context' => context_module::instance($cm->id),
 680             'objectid' => $message->id,
 681             // We set relateduserid, because when triggered from the chat daemon, the event userid is null.
 682             'relateduserid' => $chatuser->userid
 683         );
 684         $event = \mod_chat\event\message_sent::create($params);
 685         $event->add_record_snapshot('chat_messages', $message);
 686         $event->trigger();
 687     }
 688
 689     return $message->id;
 690 }
 691
 692 /**
 693  * @global object
 694  * @global object
 695  * @param object $message
 696  * @param int $courseid
 697  * @param object $sender
 698  * @param object $currentuser
 699  * @param string $chatlastrow
 700  * @return bool|string Returns HTML or false
 701  */
 702 function chat_format_message_manually($message, $courseid, $sender, $currentuser, $chatlastrow = null) {
 703     global $CFG, $USER, $OUTPUT;
 704
 705     $output = new stdClass();
 706     $output->beep = false;       // By default.
 707     $output->refreshusers = false; // By default.
 708
 709     // Use get_user_timezone() to find the correct timezone for displaying this message.
 710     // It's either the current user's timezone or else decided by some Moodle config setting.
 711     // First, "reset" $USER->timezone (which could have been set by a previous call to here)
 712     // because otherwise the value for the previous $currentuser will take precedence over $CFG->timezone.
 713     $USER->timezone = 99;
 714     $tz = get_user_timezone($currentuser->timezone);
 715
 716     // Before formatting the message time string, set $USER->timezone to the above.
 717     // This will allow dst_offset_on (called by userdate) to work correctly, otherwise the
 718     // message times appear off because DST is not taken into account when it should be.
 719     $USER->timezone = $tz;
 720     $message->strtime = userdate($message->timestamp, get_string('strftimemessage', 'chat'), $tz);
 721
 722     $message->picture = $OUTPUT->user_picture($sender, array('size' => false, 'courseid' => $courseid, 'link' => false));
 723
 724     if ($courseid) {
 725         $message->picture = "<a onclick=\"window.open('$CFG->wwwroot/user/view.php?id=$sender->id&amp;course=$courseid')\"".
 726                             " href=\"$CFG->wwwroot/user/view.php?id=$sender->id&amp;course=$courseid\">$message->picture</a>";
 727     }
 728
 729     // Calculate the row class.
 730     if ($chatlastrow !== null) {
 731         $rowclass = ' class="r'.$chatlastrow.'" ';
 732     } else {
 733         $rowclass = '';
 734     }
 735
 736     // Start processing the message.
 737
 738     if (!empty($message->system)) {
 739         // System event.
 740         $output->text = $message->strtime.': '.get_string('message'.$message->message, 'chat', fullname($sender));
 741         $output->html  = '<table class="chat-event"><tr'.$rowclass.'><td class="picture">'.$message->picture.'</td>';
 742         $output->html .= '<td class="text"><span class="event">'.$output->text.'</span></td></tr></table>';
 743         $output->basic = '<tr class="r1">
 744                             <th scope="row" class="cell c1 title"></th>
 745                             <td class="cell c2 text">' . get_string('message'.$message->message, 'chat', fullname($sender)) . '</td>
 746                             <td class="cell c3">' . $message->strtime . '</td>
 747                           </tr>';
 748         if ($message->message == 'exit' or $message->message == 'enter') {
 749             $output->refreshusers = true; // Force user panel refresh ASAP.
 750         }
 751         return $output;
 752     }
 753
 754     // It's not a system event.
 755     $text = trim($message->message);
 756
 757     // Parse the text to clean and filter it.
 758     $options = new stdClass();
 759     $options->para = false;
 760     $text = format_text($text, FORMAT_MOODLE, $options, $courseid);
 761
 762     // And now check for special cases.
 763     $patternto = '#^\s*To\s([^:]+):(.*)#';
 764     $special = false;
 765
 766     if (substr($text, 0, 5) == 'beep ') {
 767         // It's a beep!
 768         $special = true;
 769         $beepwho = trim(substr($text, 5));
 770
 771         if ($beepwho == 'all') {   // Everyone.
 772             $outinfobasic = get_string('messagebeepseveryone', 'chat', fullname($sender));
 773             $outinfo = $message->strtime . ': ' . $outinfobasic;
 774             $outmain = '';
 775
 776             $output->beep = true;  // Eventually this should be set to a filename uploaded by the user.
 777
 778         } else if ($beepwho == $currentuser->id) {  // Current user.
 779             $outinfobasic = get_string('messagebeepsyou', 'chat', fullname($sender));
 780             $outinfo = $message->strtime . ': ' . $outinfobasic;
 781             $outmain = '';
 782             $output->beep = true;
 783
 784         } else {  // Something is not caught?
 785             return false;
 786         }
 787     } else if (substr($text, 0, 1) == '/') {     // It's a user command.
 788         $special = true;
 789         $pattern = '#(^\/)(\w+).*#';
 790         preg_match($pattern, $text, $matches);
 791         $command = isset($matches[2]) ? $matches[2] : false;
 792         // Support some IRC commands.
 793         switch ($command) {
 794             case 'me':
 795                 $outinfo = $message->strtime;
 796                 $outmain = '*** <b>'.$sender->firstname.' '.substr($text, 4).'</b>';
 797                 break;
 798             default:
 799                 // Error, we set special back to false to use the classic message output.
 800                 $special = false;
 801                 break;
 802         }
 803     } else if (preg_match($patternto, $text)) {
 804         $special = true;
 805         $matches = array();
 806         preg_match($patternto, $text, $matches);
 807         if (isset($matches[1]) && isset($matches[2])) {
 808             $outinfo = $message->strtime;
 809             $outmain = $sender->firstname.' '.get_string('saidto', 'chat').' <i>'.$matches[1].'</i>: '.$matches[2];
 810         } else {
 811             // Error, we set special back to false to use the classic message output.
 812             $special = false;
 813         }
 814     }
 815
 816     if (!$special) {
 817         $outinfo = $message->strtime.' '.$sender->firstname;
 818         $outmain = $text;
 819     }
 820
 821     // Format the message as a small table.
 822
 823     $output->text  = strip_tags($outinfo.': '.$outmain);
 824
 825     $output->html  = "<table class=\"chat-message\"><tr$rowclass><td class=\"picture\" valign=\"top\">$message->picture</td>";
 826     $output->html .= "<td class=\"text\"><span class=\"title\">$outinfo</span>";
 827     if ($outmain) {
 828         $output->html .= ": $outmain";
 829         $output->basic = '<tr class="r0">
 830                             <th scope="row" class="cell c1 title">' . $sender->firstname . '</th>
 831                             <td class="cell c2 text">' . $outmain . '</td>
 832                             <td class="cell c3">' . $message->strtime . '</td>
 833                           </tr>';
 834     } else {
 835         $output->basic = '<tr class="r1">
 836                             <th scope="row" class="cell c1 title"></th>
 837                             <td class="cell c2 text">' . $outinfobasic . '</td>
 838                             <td class="cell c3">' . $message->strtime . '</td>
 839                           </tr>';
 840     }
 841     $output->html .= "</td></tr></table>";
 842     return $output;
 843 }
 844
 845 /**
 846  * Given a message object this function formats it appropriately into text and html then returns the formatted data
 847  * @global object
 848  * @param object $message
 849  * @param int $courseid
 850  * @param object $currentuser
 851  * @param string $chatlastrow
 852  * @return bool|string Returns HTML or false
 853  */
 854 function chat_format_message($message, $courseid, $currentuser, $chatlastrow=null) {
 855     global $DB;
 856
 857     static $users;     // Cache user lookups.
 858
 859     if (isset($users[$message->userid])) {
 860         $user = $users[$message->userid];
 861     } else if ($user = $DB->get_record('user', array('id' => $message->userid), user_picture::fields())) {
 862         $users[$message->userid] = $user;
 863     } else {
 864         return null;
 865     }
 866     return chat_format_message_manually($message, $courseid, $user, $currentuser, $chatlastrow);
 867 }
 868
 869 /**
 870  * @global object
 871  * @param object $message message to be displayed.
 872  * @param mixed $chatuser user chat data
 873  * @param object $currentuser current user for whom the message should be displayed.
 874  * @param int $groupingid course module grouping id
 875  * @param string $theme name of the chat theme.
 876  * @return bool|string Returns HTML or false
 877  */
 878 function chat_format_message_theme ($message, $chatuser, $currentuser, $groupingid, $theme = 'bubble') {
 879     global $CFG, $USER, $OUTPUT, $COURSE, $DB, $PAGE;
 880     require_once($CFG->dirroot.'/mod/chat/locallib.php');
 881
 882     static $users;     // Cache user lookups.
 883
 884     $result = new stdClass();
 885
 886     if (file_exists($CFG->dirroot . '/mod/chat/gui_ajax/theme/'.$theme.'/config.php')) {
 887         include($CFG->dirroot . '/mod/chat/gui_ajax/theme/'.$theme.'/config.php');
 888     }
 889
 890     if (isset($users[$message->userid])) {
 891         $sender = $users[$message->userid];
 892     } else if ($sender = $DB->get_record('user', array('id' => $message->userid), user_picture::fields())) {
 893         $users[$message->userid] = $sender;
 894     } else {
 895         return null;
 896     }
 897
 898     $USER->timezone = 99;
 899     $tz = get_user_timezone($currentuser->timezone);
 900     $USER->timezone = $tz;
 901
 902     if (empty($chatuser->course)) {
 903         $courseid = $COURSE->id;
 904     } else {
 905         $courseid = $chatuser->course;
 906     }
 907
 908     $message->strtime = userdate($message->timestamp, get_string('strftimemessage', 'chat'), $tz);
 909     $message->picture = $OUTPUT->user_picture($sender, array('courseid' => $courseid));
 910
 911     $message->picture = "<a target='_blank'".
 912                         " href=\"$CFG->wwwroot/user/view.php?id=$sender->id&amp;course=$courseid\">$message->picture</a>";
 913
 914     // Start processing the message.
 915     if (!empty($message->system)) {
 916         $result->type = 'system';
 917
 918         $senderprofile = $CFG->wwwroot.'/user/view.php?id='.$sender->id.'&amp;course='.$courseid;
 919         $event = get_string('message'.$message->message, 'chat', fullname($sender));
 920         $eventmessage = new event_message($senderprofile, fullname($sender), $message->strtime, $event, $theme);
 921
 922         $output = $PAGE->get_renderer('mod_chat');
 923         $result->html = $output->render($eventmessage);
 924
 925         return $result;
 926     }
 927
 928     // It's not a system event.
 929     $text = trim($message->message);
 930
 931     // Parse the text to clean and filter it.
 932     $options = new stdClass();
 933     $options->para = false;
 934     $text = format_text($text, FORMAT_MOODLE, $options, $courseid);
 935
 936     // And now check for special cases.
 937     $special = false;
 938     $outtime = $message->strtime;
 939
 940     // Initialise variables.
 941     $outmain = '';
 942     $patternto = '#^\s*To\s([^:]+):(.*)#';
 943
 944     if (substr($text, 0, 5) == 'beep ') {
 945         $special = true;
 946         // It's a beep!
 947         $result->type = 'beep';
 948         $beepwho = trim(substr($text, 5));
 949
 950         if ($beepwho == 'all') {   // Everyone.
 951             $outmain = get_string('messagebeepseveryone', 'chat', fullname($sender));
 952         } else if ($beepwho == $currentuser->id) {  // Current user.
 953             $outmain = get_string('messagebeepsyou', 'chat', fullname($sender));
 954         } else if ($sender->id == $currentuser->id) {  // Something is not caught?
 955             // Allow beep for a active chat user only, else user can beep anyone and get fullname.
 956             if (!empty($chatuser) && is_numeric($beepwho)) {
 957                 $chatusers = chat_get_users($chatuser->chatid, $chatuser->groupid, $groupingid);
 958                 if (array_key_exists($beepwho, $chatusers)) {
 959                     $outmain = get_string('messageyoubeep', 'chat', fullname($chatusers[$beepwho]));
 960                 } else {
 961                     $outmain = get_string('messageyoubeep', 'chat', $beepwho);
 962                 }
 963             } else {
 964                 $outmain = get_string('messageyoubeep', 'chat', $beepwho);
 965             }
 966         }
 967     } else if (substr($text, 0, 1) == '/') {     // It's a user command.
 968         $special = true;
 969         $result->type = 'command';
 970         $pattern = '#(^\/)(\w+).*#';
 971         preg_match($pattern, $text, $matches);
 972         $command = isset($matches[2]) ? $matches[2] : false;
 973         // Support some IRC commands.
 974         switch ($command) {
 975             case 'me':
 976                 $outmain = '*** <b>'.$sender->firstname.' '.substr($text, 4).'</b>';
 977                 break;
 978             default:
 979                 // Error, we set special back to false to use the classic message output.
 980                 $special = false;
 981                 break;
 982         }
 983     } else if (preg_match($patternto, $text)) {
 984         $special = true;
 985         $result->type = 'dialogue';
 986         $matches = array();
 987         preg_match($patternto, $text, $matches);
 988         if (isset($matches[1]) && isset($matches[2])) {
 989             $outmain = $sender->firstname.' <b>'.get_string('saidto', 'chat').'</b> <i>'.$matches[1].'</i>: '.$matches[2];
 990         } else {
 991             // Error, we set special back to false to use the classic message output.
 992             $special = false;
 993         }
 994     }
 995
 996     if (!$special) {
 997         $outmain = $text;
 998     }
 999
1000     $result->text = strip_tags($outtime.': '.$outmain);
1001
1002     $mymessageclass = '';
1003     if ($sender->id == $USER->id) {
1004         $mymessageclass = 'chat-message-mymessage';
1005     }
1006
1007     $senderprofile = $CFG->wwwroot.'/user/view.php?id='.$sender->id.'&amp;course='.$courseid;
1008     $usermessage = new user_message($senderprofile, fullname($sender), $message->picture,
1009                                     $mymessageclass, $outtime, $outmain, $theme);
1010
1011     $output = $PAGE->get_renderer('mod_chat');
1012     $result->html = $output->render($usermessage);
1013
1014     // When user beeps other user, then don't show any timestamp to other users in chat.
1015     if (('' === $outmain) && $special) {
1016         return false;
1017     } else {
1018         return $result;
1019     }
1020 }
1021
1022 /**
1023  * @global object $DB
1024  * @global object $CFG
1025  * @global object $COURSE
1026  * @global object $OUTPUT
1027  * @param object $users
1028  * @param object $course
1029  * @return array return formatted user list
1030  */
1031 function chat_format_userlist($users, $course) {
1032     global $CFG, $DB, $COURSE, $OUTPUT;
1033     $result = array();
1034     foreach ($users as $user) {
1035         $item = array();
1036         $item['name'] = fullname($user);
1037         $item['url'] = $CFG->wwwroot.'/user/view.php?id='.$user->id.'&amp;course='.$course->id;
1038         $item['picture'] = $OUTPUT->user_picture($user);
1039         $item['id'] = $user->id;
1040         $result[] = $item;
1041     }
1042     return $result;
1043 }
1044
1045 /**
1046  * Print json format error
1047  * @param string $level
1048  * @param string $msg
1049  */
1050 function chat_print_error($level, $msg) {
1051     header('Content-Length: ' . ob_get_length() );
1052     $error = new stdClass();
1053     $error->level = $level;
1054     $error->msg   = $msg;
1055     $response['error'] = $error;
1056     echo json_encode($response);
1057     ob_end_flush();
1058     exit;
1059 }
1060
1061 /**
1062  * List the actions that correspond to a view of this module.
1063  * This is used by the participation report.
1064  *
1065  * Note: This is not used by new logging system. Event with
1066  *       crud = 'r' and edulevel = LEVEL_PARTICIPATING will
1067  *       be considered as view action.
1068  *
1069  * @return array
1070  */
1071 function chat_get_view_actions() {
1072     return array('view', 'view all', 'report');
1073 }
1074
1075 /**
1076  * List the actions that correspond to a post of this module.
1077  * This is used by the participation report.
1078  *
1079  * Note: This is not used by new logging system. Event with
1080  *       crud = ('c' || 'u' || 'd') and edulevel = LEVEL_PARTICIPATING
1081  *       will be considered as post action.
1082  *
1083  * @return array
1084  */
1085 function chat_get_post_actions() {
1086     return array('talk');
1087 }
1088
1089 /**
1090  * @global object
1091  * @global object
1092  * @param array $courses
1093  * @param array $htmlarray Passed by reference
1094  */
1095 function chat_print_overview($courses, &$htmlarray) {
1096     global $USER, $CFG;
1097
1098     if (empty($courses) || !is_array($courses) || count($courses) == 0) {
1099         return array();
1100     }
1101
1102     if (!$chats = get_all_instances_in_courses('chat', $courses)) {
1103         return;
1104     }
1105
1106     $strchat = get_string('modulename', 'chat');
1107     $strnextsession  = get_string('nextsession', 'chat');
1108
1109     foreach ($chats as $chat) {
1110         if ($chat->chattime and $chat->schedule) {  // A chat is scheduled.
1111             $str = '<div class="chat overview"><div class="name">'.
1112                    $strchat.': <a '.($chat->visible ? '' : ' class="dimmed"').
1113                    ' href="'.$CFG->wwwroot.'/mod/chat/view.php?id='.$chat->coursemodule.'">'.
1114                    $chat->name.'</a></div>';
1115             $str .= '<div class="info">'.$strnextsession.': '.userdate($chat->chattime).'</div></div>';
1116
1117             if (empty($htmlarray[$chat->course]['chat'])) {
1118                 $htmlarray[$chat->course]['chat'] = $str;
1119             } else {
1120                 $htmlarray[$chat->course]['chat'] .= $str;
1121             }
1122         }
1123     }
1124 }
1125
1126
1127 /**
1128  * Implementation of the function for printing the form elements that control
1129  * whether the course reset functionality affects the chat.
1130  *
1131  * @param object $mform form passed by reference
1132  */
1133 function chat_reset_course_form_definition(&$mform) {
1134     $mform->addElement('header', 'chatheader', get_string('modulenameplural', 'chat'));
1135     $mform->addElement('advcheckbox', 'reset_chat', get_string('removemessages', 'chat'));
1136 }
1137
1138 /**
1139  * Course reset form defaults.
1140  *
1141  * @param object $course
1142  * @return array
1143  */
1144 function chat_reset_course_form_defaults($course) {
1145     return array('reset_chat' => 1);
1146 }
1147
1148 /**
1149  * Actual implementation of the reset course functionality, delete all the
1150  * chat messages for course $data->courseid.
1151  *
1152  * @global object
1153  * @global object
1154  * @param object $data the data submitted from the reset course.
1155  * @return array status array
1156  */
1157 function chat_reset_userdata($data) {
1158     global $CFG, $DB;
1159
1160     $componentstr = get_string('modulenameplural', 'chat');
1161     $status = array();
1162
1163     if (!empty($data->reset_chat)) {
1164         $chatessql = "SELECT ch.id
1165                         FROM {chat} ch
1166                        WHERE ch.course=?";
1167         $params = array($data->courseid);
1168
1169         $DB->delete_records_select('chat_messages', "chatid IN ($chatessql)", $params);
1170         $DB->delete_records_select('chat_messages_current', "chatid IN ($chatessql)", $params);
1171         $DB->delete_records_select('chat_users', "chatid IN ($chatessql)", $params);
1172         $status[] = array('component' => $componentstr, 'item' => get_string('removemessages', 'chat'), 'error' => false);
1173     }
1174
1175     // Updating dates - shift may be negative too.
1176     if ($data->timeshift) {
1177         shift_course_mod_dates('chat', array('chattime'), $data->timeshift, $data->courseid);
1178         $status[] = array('component' => $componentstr, 'item' => get_string('datechanged'), 'error' => false);
1179     }
1180
1181     return $status;
1182 }
1183
1184 /**
1185  * Returns all other caps used in module
1186  *
1187  * @return array
1188  */
1189 function chat_get_extra_capabilities() {
1190     return array('moodle/site:accessallgroups', 'moodle/site:viewfullnames');
1191 }
1192
1193
1194 /**
1195  * @param string $feature FEATURE_xx constant for requested feature
1196  * @return mixed True if module supports feature, null if doesn't know
1197  */
1198 function chat_supports($feature) {
1199     switch($feature) {
1200         case FEATURE_GROUPS:
1201             return true;
1202         case FEATURE_GROUPINGS:
1203             return true;
1204         case FEATURE_MOD_INTRO:
1205             return true;
1206         case FEATURE_BACKUP_MOODLE2:
1207             return true;
1208         case FEATURE_COMPLETION_TRACKS_VIEWS:
1209             return true;
1210         case FEATURE_GRADE_HAS_GRADE:
1211             return false;
1212         case FEATURE_GRADE_OUTCOMES:
1213             return true;
1214         case FEATURE_SHOW_DESCRIPTION:
1215             return true;
1216         default:
1217             return null;
1218     }
1219 }
1220
1221 function chat_extend_navigation($navigation, $course, $module, $cm) {
1222     global $CFG;
1223
1224     $currentgroup = groups_get_activity_group($cm, true);
1225
1226     if (has_capability('mod/chat:chat', context_module::instance($cm->id))) {
1227         $strenterchat    = get_string('enterchat', 'chat');
1228
1229         $target = $CFG->wwwroot.'/mod/chat/';
1230         $params = array('id' => $cm->instance);
1231
1232         if ($currentgroup) {
1233             $params['groupid'] = $currentgroup;
1234         }
1235
1236         $links = array();
1237
1238         $url = new moodle_url($target.'gui_'.$CFG->chat_method.'/index.php', $params);
1239         $action = new popup_action('click', $url, 'chat'.$course->id.$cm->instance.$currentgroup,
1240                                    array('height' => 500, 'width' => 700));
1241         $links[] = new action_link($url, $strenterchat, $action);
1242
1243         $url = new moodle_url($target.'gui_basic/index.php', $params);
1244         $action = new popup_action('click', $url, 'chat'.$course->id.$cm->instance.$currentgroup,
1245                                    array('height' => 500, 'width' => 700));
1246         $links[] = new action_link($url, get_string('noframesjs', 'message'), $action);
1247
1248         foreach ($links as $link) {
1249             $navigation->add($link->text, $link, navigation_node::TYPE_SETTING, null , null, new pix_icon('i/group' , ''));
1250         }
1251     }
1252
1253     $chatusers = chat_get_users($cm->instance, $currentgroup, $cm->groupingid);
1254     if (is_array($chatusers) && count($chatusers) > 0) {
1255         $users = $navigation->add(get_string('currentusers', 'chat'));
1256         foreach ($chatusers as $chatuser) {
1257             $userlink = new moodle_url('/user/view.php', array('id' => $chatuser->id, 'course' => $course->id));
1258             $users->add(fullname($chatuser).' '.format_time(time() - $chatuser->lastmessageping),
1259                         $userlink, navigation_node::TYPE_USER, null, null, new pix_icon('i/user', ''));
1260         }
1261     }
1262 }
1263
1264 /**
1265  * Adds module specific settings to the settings block
1266  *
1267  * @param settings_navigation $settings The settings navigation object
1268  * @param navigation_node $chatnode The node to add module settings to
1269  */
1270 function chat_extend_settings_navigation(settings_navigation $settings, navigation_node $chatnode) {
1271     global $DB, $PAGE, $USER;
1272     $chat = $DB->get_record("chat", array("id" => $PAGE->cm->instance));
1273
1274     if ($chat->chattime && $chat->schedule) {
1275         $nextsessionnode = $chatnode->add(get_string('nextsession', 'chat').
1276                                           ': '.userdate($chat->chattime).
1277                                           ' ('.usertimezone($USER->timezone));
1278         $nextsessionnode->add_class('note');
1279     }
1280
1281     $currentgroup = groups_get_activity_group($PAGE->cm, true);
1282     if ($currentgroup) {
1283         $groupselect = " AND groupid = '$currentgroup'";
1284     } else {
1285         $groupselect = '';
1286     }
1287
1288     if ($chat->studentlogs || has_capability('mod/chat:readlog', $PAGE->cm->context)) {
1289         if ($DB->get_records_select('chat_messages', "chatid = ? $groupselect", array($chat->id))) {
1290             $chatnode->add(get_string('viewreport', 'chat'), new moodle_url('/mod/chat/report.php', array('id' => $PAGE->cm->id)));
1291         }
1292     }
1293 }
1294
1295 /**
1296  * user logout event handler
1297  *
1298  * @param \core\event\user_loggedout $event The event.
1299  * @return void
1300  */
1301 function chat_user_logout(\core\event\user_loggedout $event) {
1302     global $DB;
1303     $DB->delete_records('chat_users', array('userid' => $event->objectid));
1304 }
1305
1306 /**
1307  * Return a list of page types
1308  * @param string $pagetype current page type
1309  * @param stdClass $parentcontext Block's parent context
1310  * @param stdClass $currentcontext Current context of block
1311  */
1312 function chat_page_type_list($pagetype, $parentcontext, $currentcontext) {
1313     $modulepagetype = array('mod-chat-*' => get_string('page-mod-chat-x', 'chat'));
1314     return $modulepagetype;
1315 }