mod/chat/lib.php

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