mod/chat/lib.php

   1 <?php  // $Id$
   2
   3 /// Library of functions and constants for module chat
   4 require_once($CFG->libdir.'/pagelib.php');
   5
   6
   7 // The HTML head for the message window to start with (<!-- nix --> is used to get some browsers starting with output
   8 $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 bgcolor=\"#FFFFFF\">\n\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n";
   9
  10 // The HTML head for the message window to start with (with js scrolling)
  11 $CHAT_HTMLHEAD_JS = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\" \"http://www.w3.org/TR/REC-html40/loose.dtd\"><html><head><script type=\"text/javascript\">\n//<![CDATA[\nfunction move()\n{\nif (scroll_active) window.scroll(1,400000);\nwindow.setTimeout(\"move()\",100);\n}\nscroll_active = true;\nmove();\n//]]>\n</script>\n</head>\n<body bgcolor=\"#FFFFFF\" onBlur=\"scroll_active = true\" onFocus=\"scroll_active = false\">\n\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n";
  12
  13 // The HTML code for standard empty pages (e.g. if a user was kicked out)
  14 $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 bgcolor=\"#FFFFFF\"></body></html>";
  15
  16 // The HTML head for the message input page
  17 $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 bgcolor=\"#FFFFFF\">";
  18
  19 // The HTML code for the message input page, with JavaScript
  20 $CHAT_HTMLHEAD_MSGINPUT_JS = "<!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>\n<script type=\"text/javascript\">\n//<![CDATA[\nscroll_active = true;\nfunction empty_field_and_submit()\n{\ndocument.fdummy.arsc_message.value=document.f.arsc_message.value;\ndocument.fdummy.submit();\ndocument.f.arsc_message.focus();\ndocument.f.arsc_message.select();\nreturn false;\n}\n//]]>\n</script>\n</head><body bgcolor=\"#FFFFFF\" OnLoad=\"document.f.arsc_message.focus();document.f.arsc_message.select();\">";
  21
  22 // Dummy data that gets output to the browser as needed, in order to make it show output
  23 $CHAT_DUMMY_DATA = "<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n<!-- nix -->\n";
  24
  25 function chat_add_instance($chat) {
  26 /// Given an object containing all the necessary data,
  27 /// (defined by the form in mod.html) this function
  28 /// will create a new instance and return the id number
  29 /// of the new instance.
  30
  31     $chat->timemodified = time();
  32
  33     if ($returnid = insert_record("chat", $chat)) {
  34
  35         $event = NULL;
  36         $event->name        = $chat->name;
  37         $event->description = $chat->intro;
  38         $event->courseid    = $chat->course;
  39         $event->groupid     = 0;
  40         $event->userid      = 0;
  41         $event->modulename  = 'chat';
  42         $event->instance    = $returnid;
  43         $event->eventtype   = $chat->schedule;
  44         $event->timestart   = $chat->chattime;
  45         $event->timeduration = 0;
  46
  47         add_event($event);
  48     }
  49
  50     return $returnid;
  51 }
  52
  53
  54 function chat_update_instance($chat) {
  55 /// Given an object containing all the necessary data,
  56 /// (defined by the form in mod.html) this function
  57 /// will update an existing instance with new data.
  58
  59     $chat->timemodified = time();
  60     $chat->id = $chat->instance;
  61
  62
  63     if ($returnid = update_record("chat", $chat)) {
  64
  65         $event = new object();
  66
  67         if ($event->id = get_field('event', 'id', 'modulename', 'chat', 'instance', $chat->id)) {
  68
  69             $event->name        = $chat->name;
  70             $event->description = $chat->intro;
  71             $event->timestart   = $chat->chattime;
  72
  73             update_event($event);
  74         }
  75     }
  76
  77     return $returnid;
  78 }
  79
  80
  81 function chat_delete_instance($id) {
  82 /// Given an ID of an instance of this module,
  83 /// this function will permanently delete the instance
  84 /// and any data that depends on it.
  85
  86     if (! $chat = get_record('chat', 'id', $id)) {
  87         return false;
  88     }
  89
  90     $result = true;
  91
  92     # Delete any dependent records here #
  93
  94     if (! delete_records('chat', 'id', $chat->id)) {
  95         $result = false;
  96     }
  97     if (! delete_records('chat_messages', 'chatid', $chat->id)) {
  98         $result = false;
  99     }
 100     if (! delete_records('chat_users', 'chatid', $chat->id)) {
 101         $result = false;
 102     }
 103
 104     $pagetypes = page_import_types('mod/chat/');
 105     foreach($pagetypes as $pagetype) {
 106         if(!delete_records('block_instance', 'pageid', $chat->id, 'pagetype', $pagetype)) {
 107             $result = false;
 108         }
 109     }
 110
 111     if (! delete_records('event', 'modulename', 'chat', 'instance', $chat->id)) {
 112         $result = false;
 113     }
 114
 115     return $result;
 116 }
 117
 118 function chat_user_outline($course, $user, $mod, $chat) {
 119 /// Return a small object with summary information about what a
 120 /// user has done with a given particular instance of this module
 121 /// Used for user activity reports.
 122 /// $return->time = the time they did it
 123 /// $return->info = a short text description
 124
 125     $return = NULL;
 126     return $return;
 127 }
 128
 129 function chat_user_complete($course, $user, $mod, $chat) {
 130 /// Print a detailed representation of what a  user has done with
 131 /// a given particular instance of this module, for user activity reports.
 132
 133     return true;
 134 }
 135
 136 function chat_print_recent_activity($course, $viewfullnames, $timestart) {
 137 /// Given a course and a date, prints a summary of all chat rooms past and present
 138 /// This function is called from course/lib.php: print_recent_activity()
 139
 140     global $CFG, $USER;
 141
 142     // this is approximate only, but it is really fast ;-)
 143     $timeout = $CFG->chat_old_ping * 10;
 144
 145     if (!$mcms = get_records_sql("SELECT cm.id, MAX(chm.timestamp) AS lasttime
 146                                     FROM {$CFG->prefix}course_modules cm
 147                                          JOIN {$CFG->prefix}modules md        ON md.id = cm.module
 148                                          JOIN {$CFG->prefix}chat ch           ON ch.id = cm.instance
 149                                          JOIN {$CFG->prefix}chat_messages chm ON chm.chatid = ch.id
 150                                    WHERE chm.timestamp > $timestart AND ch.course = {$course->id} AND md.name = 'chat'
 151                                 GROUP BY cm.id
 152                                 ORDER BY lasttime ASC")) {
 153          return false;
 154     }
 155
 156     $past     = array();
 157     $current  = array();
 158     $modinfo =& get_fast_modinfo($course); // reference needed because we might load the groups
 159
 160     foreach ($mcms as $cmid=>$mcm) {
 161         if (!array_key_exists($cmid, $modinfo->cms)) {
 162             continue;
 163         }
 164         $cm = $modinfo->cms[$cmid];
 165         $cm->lasttime = $mcm->lasttime;
 166         if (!$modinfo->cms[$cm->id]->uservisible) {
 167             continue;
 168         }
 169
 170         if (groups_get_activity_groupmode($cm) != SEPARATEGROUPS
 171          or has_capability('moodle/site:accessallgroups', get_context_instance(CONTEXT_MODULE, $cm->id))) {
 172             if ($timeout > time() - $cm->lasttime) {
 173                 $current[] = $cm;
 174             } else {
 175                 $past[] = $cm;
 176             }
 177
 178             continue;
 179         }
 180
 181         if (is_null($modinfo->groups)) {
 182             $modinfo->groups = groups_get_user_groups($course->id); // load all my groups and cache it in modinfo
 183         }
 184
 185         // verify groups in separate mode
 186         if (!$mygroupids = $modinfo->groups[$cm->groupingid]) {
 187             continue;
 188         }
 189
 190         // ok, last post was not for my group - we have to query db to get last message from one of my groups
 191         // only minor problem is that the order will not be correct
 192         $mygroupids = implode(',', $mygroupids);
 193         $cm->mygroupids = $mygroupids;
 194
 195         if (!$mcm = get_record_sql("SELECT cm.id, MAX(chm.timestamp) AS lasttime
 196                                       FROM {$CFG->prefix}course_modules cm
 197                                            JOIN {$CFG->prefix}chat ch           ON ch.id = cm.instance
 198                                            JOIN {$CFG->prefix}chat_messages chm ON chm.chatid = ch.id
 199                                      WHERE chm.timestamp > $timestart AND cm.id = {$cm->id} AND
 200                                            (chm.groupid IN ($mygroupids) OR chm.groupid = 0)
 201                                   GROUP BY cm.id")) {
 202              continue;
 203         }
 204
 205         $cm->lasttime = $mcm->lasttime;
 206         if ($timeout > time() - $cm->lasttime) {
 207             $current[] = $cm;
 208         } else {
 209             $past[] = $cm;
 210         }
 211     }
 212
 213     if (!$past and !$current) {
 214         return false;
 215     }
 216
 217     $strftimerecent = get_string('strftimerecent');
 218
 219     if ($past) {
 220         print_headline(get_string('pastchats', 'chat').':');
 221
 222         foreach ($past as $cm) {
 223             $link = $CFG->wwwroot.'/mod/chat/view.php?id='.$cm->id;
 224             $date = userdate($cm->lasttime, $strftimerecent);
 225             echo '<div class="head"><div class="date">'.$date.'</div></div>';
 226             echo '<div class="info"><a href="'.$link.'">'.format_string($cm->name,true).'</a></div>';
 227         }
 228     }
 229
 230     if ($current) {
 231         print_headline(get_string('currentchats', 'chat').':');
 232
 233         $oldest = floor((time()-$CFG->chat_old_ping)/10)*10;  // better db caching
 234
 235         $timeold    = time() - $CFG->chat_old_ping;
 236         $timeold    = floor($timeold/10)*10;  // better db caching
 237         $timeoldext = time() - ($CFG->chat_old_ping*10); // JSless gui_basic needs much longer timeouts
 238         $timeoldext = floor($timeoldext/10)*10;  // better db caching
 239
 240         $timeout = "AND (chu.version<>'basic' AND chu.lastping>$timeold) OR (chu.version='basic' AND chu.lastping>$timeoldext)";
 241
 242         foreach ($current as $cm) {
 243             //count users first
 244             if (isset($cm->mygroupids)) {
 245                 $groupselect = "AND (chu.groupid IN ({$cm->mygroupids}) OR chu.groupid = 0)";
 246             } else {
 247                 $groupselect = "";
 248             }
 249
 250             if (!$users = get_records_sql("SELECT u.id, u.firstname, u.lastname, u.email, u.picture
 251                                              FROM {$CFG->prefix}course_modules cm
 252                                              JOIN {$CFG->prefix}chat ch        ON ch.id = cm.instance
 253                                              JOIN {$CFG->prefix}chat_users chu ON chu.chatid = ch.id
 254                                              JOIN {$CFG->prefix}user u         ON u.id = chu.userid
 255                                             WHERE cm.id = {$cm->id} $timeout $groupselect
 256                                          GROUP BY u.id, u.firstname, u.lastname, u.email, u.picture")) {
 257             }
 258
 259             $link = $CFG->wwwroot.'/mod/chat/view.php?id='.$cm->id;
 260             $date = userdate($cm->lasttime, $strftimerecent);
 261
 262             echo '<div class="head"><div class="date">'.$date.'</div></div>';
 263             echo '<div class="info"><a href="'.$link.'">'.format_string($cm->name,true).'</a></div>';
 264             echo '<div class="userlist">';
 265             if ($users) {
 266                 echo '<ul>';
 267                     foreach ($users as $user) {
 268                         echo '<li>'.fullname($user, $viewfullnames).'</li>';
 269                     }
 270                 echo '</ul>';
 271             }
 272             echo '</div>';
 273         }
 274     }
 275
 276     return true;
 277 }
 278
 279
 280 function chat_cron () {
 281 /// Function to be run periodically according to the moodle cron
 282 /// This function searches for things that need to be done, such
 283 /// as sending out mail, toggling flags etc ...
 284
 285     global $CFG;
 286
 287     chat_update_chat_times();
 288
 289     chat_delete_old_users();
 290
 291     /// Delete old messages with a
 292     /// single SQL query.
 293     $subselect = "SELECT c.keepdays
 294                     FROM {$CFG->prefix}chat c
 295                    WHERE c.id = {$CFG->prefix}chat_messages.chatid";
 296
 297     $sql = "DELETE
 298               FROM {$CFG->prefix}chat_messages
 299              WHERE ($subselect) > 0 AND timestamp < ( ".time()." -($subselect) * 24 * 3600)";
 300
 301     execute_sql($sql, false);
 302
 303     return true;
 304 }
 305
 306 function chat_get_participants($chatid, $groupid=0) {
 307 //Returns the users with data in one chat
 308 //(users with records in chat_messages, students)
 309
 310     global $CFG;
 311
 312     if ($groupid) {
 313         $groupselect = " AND (c.groupid='$groupid' OR c.groupid='0')";
 314     } else {
 315         $groupselect = "";
 316     }
 317
 318     //Get students
 319     $students = get_records_sql("SELECT DISTINCT u.id, u.id
 320                                  FROM {$CFG->prefix}user u,
 321                                       {$CFG->prefix}chat_messages c
 322                                  WHERE c.chatid = '$chatid' $groupselect
 323                                    AND u.id = c.userid");
 324
 325     //Return students array (it contains an array of unique users)
 326     return ($students);
 327 }
 328
 329 function chat_refresh_events($courseid = 0) {
 330 // This standard function will check all instances of this module
 331 // and make sure there are up-to-date events created for each of them.
 332 // If courseid = 0, then every chat event in the site is checked, else
 333 // only chat events belonging to the course specified are checked.
 334 // This function is used, in its new format, by restore_refresh_events()
 335
 336     if ($courseid) {
 337         if (! $chats = get_records("chat", "course", $courseid)) {
 338             return true;
 339         }
 340     } else {
 341         if (! $chats = get_records("chat")) {
 342             return true;
 343         }
 344     }
 345     $moduleid = get_field('modules', 'id', 'name', 'chat');
 346
 347     foreach ($chats as $chat) {
 348         $event = NULL;
 349         $event->name        = addslashes($chat->name);
 350         $event->description = addslashes($chat->intro);
 351         $event->timestart   = $chat->chattime;
 352
 353         if ($event->id = get_field('event', 'id', 'modulename', 'chat', 'instance', $chat->id)) {
 354             update_event($event);
 355
 356         } else {
 357             $event->courseid    = $chat->course;
 358             $event->groupid     = 0;
 359             $event->userid      = 0;
 360             $event->modulename  = 'chat';
 361             $event->instance    = $chat->id;
 362             $event->eventtype   = $chat->schedule;
 363             $event->timeduration = 0;
 364             $event->visible     = get_field('course_modules', 'visible', 'module', $moduleid, 'instance', $chat->id);
 365
 366             add_event($event);
 367         }
 368     }
 369     return true;
 370 }
 371
 372
 373 //////////////////////////////////////////////////////////////////////
 374 /// Functions that require some SQL
 375
 376 function chat_get_users($chatid, $groupid=0, $groupingid=0) {
 377
 378     global $CFG;
 379
 380     if ($groupid) {
 381         $groupselect = " AND (c.groupid='$groupid' OR c.groupid='0')";
 382     } else {
 383         $groupselect = "";
 384     }
 385
 386     if (!empty($CFG->enablegroupings) && !(empty($groupingid))) {
 387         $groupingjoin = "INNER JOIN {$CFG->prefix}groups_members gm ON u.id = gm.userid
 388                          INNER JOIN {$CFG->prefix}groupings_groups gg ON gm.groupid = gg.groupid AND gg.groupingid = $groupingid ";
 389
 390     } else {
 391         $groupingjoin = '';
 392     }
 393
 394     return get_records_sql("SELECT DISTINCT u.id, u.firstname, u.lastname, u.picture, c.lastmessageping, c.firstping, u.imagealt
 395                               FROM {$CFG->prefix}chat_users c
 396                                 INNER JOIN {$CFG->prefix}user u ON u.id = c.userid
 397                                 $groupingjoin
 398                              WHERE c.chatid = '$chatid'
 399                                 $groupselect
 400                              ORDER BY c.firstping ASC");
 401 }
 402
 403 function chat_get_latest_message($chatid, $groupid=0) {
 404 /// Efficient way to extract just the latest message
 405 /// Uses ADOdb directly instead of get_record_sql()
 406 /// because the LIMIT command causes problems with
 407 /// the developer debugging in there.
 408
 409     global $db, $CFG;
 410
 411     if ($groupid) {
 412         $groupselect = " AND (groupid='$groupid' OR groupid='0')";
 413     } else {
 414         $groupselect = "";
 415     }
 416
 417     if (!$rs = $db->SelectLimit("SELECT *
 418                                  FROM {$CFG->prefix}chat_messages
 419                                  WHERE chatid = '$chatid' $groupselect
 420                                  ORDER BY timestamp DESC", 1)) {
 421         return false;
 422     }
 423
 424     $result = rs_fetch_record($rs);
 425
 426     rs_close($rs);
 427
 428     return $result;
 429 }
 430
 431
 432 //////////////////////////////////////////////////////////////////////
 433 // login if not already logged in
 434
 435 function chat_login_user($chatid, $version, $groupid, $course) {
 436     global $USER;
 437     if (($version != 'sockets') and $chatuser = get_record_select('chat_users', "chatid='$chatid' AND userid='$USER->id' AND groupid='$groupid'")) {
 438         $chatuser->version  = $version;
 439         $chatuser->ip       = $USER->lastip;
 440         $chatuser->lastping = time();
 441         $chatuser->lang     = current_language();
 442
 443         // Sometimes $USER->lastip is not setup properly
 444         // during login. Update with current value if possible
 445         // or provide a dummy value for the db
 446         if (empty($chatuser->ip)) {
 447             $chatuser->ip = getremoteaddr();
 448             if (empty($chatuser->ip)) {
 449                 $chatuser->ip = '';
 450             }
 451         }
 452
 453         if (($chatuser->course != $course->id)
 454          or ($chatuser->userid != $USER->id)) {
 455             return false;
 456         }
 457         if (!update_record('chat_users', $chatuser)) {
 458             return false;
 459         }
 460     } else {
 461         $chatuser = new object();
 462         $chatuser->chatid   = $chatid;
 463         $chatuser->userid   = $USER->id;
 464         $chatuser->groupid  = $groupid;
 465         $chatuser->version  = $version;
 466         $chatuser->ip       = $USER->lastip;
 467         $chatuser->lastping = $chatuser->firstping = $chatuser->lastmessageping = time();
 468         $chatuser->sid      = random_string(32);
 469         $chatuser->course   = $course->id; //caching - needed for current_language too
 470         $chatuser->lang     = current_language(); //caching - to resource intensive to find out later
 471
 472         // Sometimes $USER->lastip is not setup properly
 473         // during login. Update with current value if possible
 474         // or provide a dummy value for the db
 475         if (empty($chatuser->ip)) {
 476             $chatuser->ip = getremoteaddr();
 477             if (empty($chatuser->ip)) {
 478                 $chatuser->ip = '';
 479             }
 480         }
 481
 482
 483         if (!insert_record('chat_users', $chatuser)) {
 484             return false;
 485         }
 486
 487         if ($version == 'sockets') {
 488             // do not send 'enter' message, chatd will do it
 489         } else {
 490             $message = new object();
 491             $message->chatid    = $chatuser->chatid;
 492             $message->userid    = $chatuser->userid;
 493             $message->groupid   = $groupid;
 494             $message->message   = 'enter';
 495             $message->system    = 1;
 496             $message->timestamp = time();
 497
 498             if (!insert_record('chat_messages', $message)) {
 499                 error('Could not insert a chat message!');
 500             }
 501         }
 502     }
 503
 504     return $chatuser->sid;
 505 }
 506
 507 function chat_delete_old_users() {
 508 // Delete the old and in the way
 509
 510     global $CFG;
 511
 512     $timeold = time() - $CFG->chat_old_ping;
 513     $timeoldext = time() - ($CFG->chat_old_ping*10); // JSless gui_basic needs much longer timeouts
 514
 515     $query = "(version<>'basic' AND lastping<'$timeold') OR (version='basic' AND lastping<'$timeoldext')";
 516
 517     if ($oldusers = get_records_select('chat_users', $query) ) {
 518         delete_records_select('chat_users', $query);
 519         foreach ($oldusers as $olduser) {
 520             $message = new object();
 521             $message->chatid    = $olduser->chatid;
 522             $message->userid    = $olduser->userid;
 523             $message->groupid   = $olduser->groupid;
 524             $message->message   = 'exit';
 525             $message->system    = 1;
 526             $message->timestamp = time();
 527
 528             if (!insert_record('chat_messages', $message)) {
 529                 error('Could not insert a chat message!');
 530             }
 531         }
 532     }
 533 }
 534
 535
 536 function chat_update_chat_times($chatid=0) {
 537 /// Updates chat records so that the next chat time is correct
 538
 539     $timenow = time();
 540     if ($chatid) {
 541         if (!$chats[] = get_record_select("chat", "id = '$chatid' AND chattime <= '$timenow' AND schedule > '0'")) {
 542             return;
 543         }
 544     } else {
 545         if (!$chats = get_records_select("chat", "chattime <= '$timenow' AND schedule > '0'")) {
 546             return;
 547         }
 548     }
 549
 550     foreach ($chats as $chat) {
 551         unset($chat->name);
 552         unset($chat->intro);
 553         switch ($chat->schedule) {
 554             case 1: // Single event - turn off schedule and disable
 555                     $chat->chattime = 0;
 556                     $chat->schedule = 0;
 557                     break;
 558             case 2: // Repeat daily
 559                     while ($chat->chattime <= $timenow) {
 560                         $chat->chattime += 24 * 3600;
 561                     }
 562                     break;
 563             case 3: // Repeat weekly
 564                     while ($chat->chattime <= $timenow) {
 565                         $chat->chattime += 7 * 24 * 3600;
 566                     }
 567                     break;
 568         }
 569         update_record("chat", $chat);
 570
 571         $event = NULL;           // Update calendar too
 572         $cond = "modulename='chat' AND instance = {$chat->id}
 573                  AND timestart != {$chat->chattime}";
 574         if ($event->id = get_field_select('event', 'id', $cond)) {
 575             $event->timestart   = $chat->chattime;
 576             update_event($event);
 577         }
 578     }
 579 }
 580
 581
 582 function chat_format_message_manually($message, $courseid, $sender, $currentuser, $chat_lastrow=NULL) {
 583     global $CFG, $USER;
 584
 585     $output = new object();
 586     $output->beep = false;       // by default
 587     $output->refreshusers = false; // by default
 588
 589     // Use get_user_timezone() to find the correct timezone for displaying this message:
 590     // It's either the current user's timezone or else decided by some Moodle config setting
 591     // First, "reset" $USER->timezone (which could have been set by a previous call to here)
 592     // because otherwise the value for the previous $currentuser will take precedence over $CFG->timezone
 593     $USER->timezone = 99;
 594     $tz = get_user_timezone($currentuser->timezone);
 595
 596     // Before formatting the message time string, set $USER->timezone to the above.
 597     // This will allow dst_offset_on (called by userdate) to work correctly, otherwise the
 598     // message times appear off because DST is not taken into account when it should be.
 599     $USER->timezone = $tz;
 600     $message->strtime = userdate($message->timestamp, get_string('strftimemessage', 'chat'), $tz);
 601
 602     $message->picture = print_user_picture($sender->id, 0, $sender->picture, false, true, false);
 603     if ($courseid) {
 604         $message->picture = "<a onclick=\"window.open('$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>";
 605     }
 606
 607     //Calculate the row class
 608     if ($chat_lastrow !== NULL) {
 609         $rowclass = ' class="r'.$chat_lastrow.'" ';
 610     } else {
 611         $rowclass = '';
 612     }
 613
 614     // Start processing the message
 615
 616     if(!empty($message->system)) {
 617         // System event
 618         $output->text = $message->strtime.': '.get_string('message'.$message->message, 'chat', fullname($sender));
 619         $output->html  = '<table class="chat-event"><tr'.$rowclass.'><td class="picture">'.$message->picture.'</td><td class="text">';
 620         $output->html .= '<span class="event">'.$output->text.'</span></td></tr></table>';
 621         $output->basic = '<dl><dt class="event">'.$message->strtime.': '.get_string('message'.$message->message, 'chat', fullname($sender)).'</dt></dl>';
 622
 623         if($message->message == 'exit' or $message->message == 'enter') {
 624             $output->refreshusers = true; //force user panel refresh ASAP
 625         }
 626         return $output;
 627     }
 628
 629     // It's not a system event
 630
 631     $text = $message->message;
 632
 633     /// Parse the text to clean and filter it
 634
 635     $options = new object();
 636     $options->para = false;
 637     $text = format_text($text, FORMAT_MOODLE, $options, $courseid);
 638
 639     // And now check for special cases
 640     $special = false;
 641
 642     if (substr($text, 0, 5) == 'beep ') {
 643         /// It's a beep!
 644         $special = true;
 645         $beepwho = trim(substr($text, 5));
 646
 647         if ($beepwho == 'all') {   // everyone
 648             $outinfo = $message->strtime.': '.get_string('messagebeepseveryone', 'chat', fullname($sender));
 649             $outmain = '';
 650             $output->beep = true;  // (eventually this should be set to
 651                                    //  to a filename uploaded by the user)
 652
 653         } else if ($beepwho == $currentuser->id) {  // current user
 654             $outinfo = $message->strtime.': '.get_string('messagebeepsyou', 'chat', fullname($sender));
 655             $outmain = '';
 656             $output->beep = true;
 657
 658         } else {  //something is not caught?
 659             return false;
 660         }
 661     } else if (substr($text, 0, 1) == '/') {     /// It's a user command
 662         if (trim(substr($text, 0, 4)) == '/me') {
 663             $special = true;
 664             $outinfo = $message->strtime;
 665             $outmain = $sender->firstname.' '.substr($text, 4);
 666         }
 667     }
 668
 669     if(!$special) {
 670         $outinfo = $message->strtime.' '.$sender->firstname;
 671         $outmain = $text;
 672     }
 673
 674     /// Format the message as a small table
 675
 676     $output->text  = strip_tags($outinfo.': '.$outmain);
 677
 678     $output->html  = "<table class=\"chat-message\"><tr$rowclass><td class=\"picture\" valign=\"top\">$message->picture</td><td class=\"text\">";
 679     $output->html .= "<span class=\"title\">$outinfo</span>";
 680     if ($outmain) {
 681         $output->html .= ": $outmain";
 682         $output->basic = '<dl><dt class="title">'.$outinfo.':</dt><dd class="text">'.$outmain.'</dd></dl>';
 683     } else {
 684         $output->basic = '<dl><dt class="title">'.$outinfo.'</dt></dl>';
 685     }
 686     $output->html .= "</td></tr></table>";
 687     return $output;
 688 }
 689
 690 function chat_format_message($message, $courseid, $currentuser, $chat_lastrow=NULL) {
 691 /// Given a message object full of information, this function
 692 /// formats it appropriately into text and html, then
 693 /// returns the formatted data.
 694
 695     static $users;     // Cache user lookups
 696
 697     if (isset($users[$message->userid])) {
 698         $user = $users[$message->userid];
 699     } else if ($user = get_record('user', 'id', $message->userid, '','','','','id,picture,firstname,lastname')) {
 700         $users[$message->userid] = $user;
 701     } else {
 702         return NULL;
 703     }
 704     return chat_format_message_manually($message, $courseid, $user, $currentuser, $chat_lastrow);
 705 }
 706
 707 function chat_get_view_actions() {
 708     return array('view','view all','report');
 709 }
 710
 711 function chat_get_post_actions() {
 712     return array('talk');
 713 }
 714
 715 function chat_print_overview($courses, &$htmlarray) {
 716     global $USER, $CFG;
 717
 718     if (empty($courses) || !is_array($courses) || count($courses) == 0) {
 719         return array();
 720     }
 721
 722     if (!$chats = get_all_instances_in_courses('chat',$courses)) {
 723         return;
 724     }
 725
 726     $strchat = get_string('modulename', 'chat');
 727     $strnextsession  = get_string('nextsession', 'chat');
 728
 729     foreach ($chats as $chat) {
 730         if ($chat->chattime and $chat->schedule) {  // A chat is scheduled
 731             $str = '<div class="chat overview"><div class="name">'.
 732                    $strchat.': <a '.($chat->visible?'':' class="dimmed"').
 733                    ' href="'.$CFG->wwwroot.'/mod/chat/view.php?id='.$chat->coursemodule.'">'.
 734                    $chat->name.'</a></div>';
 735             $str .= '<div class="info">'.$strnextsession.': '.userdate($chat->chattime).'</div></div>';
 736
 737             if (empty($htmlarray[$chat->course]['chat'])) {
 738                 $htmlarray[$chat->course]['chat'] = $str;
 739             } else {
 740                 $htmlarray[$chat->course]['chat'] .= $str;
 741             }
 742         }
 743     }
 744 }
 745
 746
 747 /**
 748  * Implementation of the function for printing the form elements that control
 749  * whether the course reset functionality affects the chat.
 750  * @param $mform form passed by reference
 751  */
 752 function chat_reset_course_form_definition(&$mform) {
 753     $mform->addElement('header', 'chatheader', get_string('modulenameplural', 'chat'));
 754     $mform->addElement('advcheckbox', 'reset_chat', get_string('removemessages','chat'));
 755 }
 756
 757 /**
 758  * Course reset form defaults.
 759  */
 760 function chat_reset_course_form_defaults($course) {
 761     return array('reset_chat'=>1);
 762 }
 763
 764 /**
 765  * Actual implementation of the rest coures functionality, delete all the
 766  * chat messages for course $data->courseid.
 767  * @param $data the data submitted from the reset course.
 768  * @return array status array
 769  */
 770 function chat_reset_userdata($data) {
 771     global $CFG;
 772
 773     $componentstr = get_string('modulenameplural', 'chat');
 774     $status = array();
 775
 776     if (!empty($data->reset_chat)) {
 777         $chatessql = "SELECT ch.id
 778                         FROM {$CFG->prefix}chat ch
 779                        WHERE ch.course={$data->courseid}";
 780
 781         delete_records_select('chat_messages', "chatid IN ($chatessql)");
 782         delete_records_select('chat_users', "chatid IN ($chatessql)");
 783         $status[] = array('component'=>$componentstr, 'item'=>get_string('removemessages', 'chat'), 'error'=>false);
 784     }
 785
 786     /// updating dates - shift may be negative too
 787     if ($data->timeshift) {
 788         shift_course_mod_dates('chat', array('chattime'), $data->timeshift, $data->courseid);
 789         $status[] = array('component'=>$componentstr, 'item'=>get_string('datechanged'), 'error'=>false);
 790     }
 791
 792     return $status;
 793 }
 794
 795 /**
 796  * Returns all other caps used in module
 797  */
 798 function chat_get_extra_capabilities() {
 799     return array('moodle/site:accessallgroups', 'moodle/site:viewfullnames');
 800 }
 801
 802 ?>