message/lib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Library functions for messaging
  19  *
  20  * @package   core_message
  21  * @copyright 2008 Luis Rodrigues
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 require_once($CFG->libdir.'/eventslib.php');
  26
  27 define ('MESSAGE_SHORTLENGTH', 300);
  28
  29 define ('MESSAGE_DISCUSSION_WIDTH',600);
  30 define ('MESSAGE_DISCUSSION_HEIGHT',500);
  31
  32 define ('MESSAGE_SHORTVIEW_LIMIT', 8);//the maximum number of messages to show on the short message history
  33
  34 define('MESSAGE_HISTORY_SHORT',0);
  35 define('MESSAGE_HISTORY_ALL',1);
  36
  37 define('MESSAGE_VIEW_UNREAD_MESSAGES','unread');
  38 define('MESSAGE_VIEW_RECENT_CONVERSATIONS','recentconversations');
  39 define('MESSAGE_VIEW_RECENT_NOTIFICATIONS','recentnotifications');
  40 define('MESSAGE_VIEW_CONTACTS','contacts');
  41 define('MESSAGE_VIEW_BLOCKED','blockedusers');
  42 define('MESSAGE_VIEW_COURSE','course_');
  43 define('MESSAGE_VIEW_SEARCH','search');
  44
  45 define('MESSAGE_SEARCH_MAX_RESULTS', 200);
  46
  47 define('MESSAGE_CONTACTS_PER_PAGE',10);
  48 define('MESSAGE_MAX_COURSE_NAME_LENGTH', 30);
  49
  50 /**
  51  * Define contants for messaging default settings population. For unambiguity of
  52  * plugin developer intentions we use 4-bit value (LSB numbering):
  53  * bit 0 - whether to send message when user is loggedin (MESSAGE_DEFAULT_LOGGEDIN)
  54  * bit 1 - whether to send message when user is loggedoff (MESSAGE_DEFAULT_LOGGEDOFF)
  55  * bit 2..3 - messaging permission (MESSAGE_DISALLOWED|MESSAGE_PERMITTED|MESSAGE_FORCED)
  56  *
  57  * MESSAGE_PERMITTED_MASK contains the mask we use to distinguish permission setting
  58  */
  59
  60 define('MESSAGE_DEFAULT_LOGGEDIN', 0x01); // 0001
  61 define('MESSAGE_DEFAULT_LOGGEDOFF', 0x02); // 0010
  62
  63 define('MESSAGE_DISALLOWED', 0x04); // 0100
  64 define('MESSAGE_PERMITTED', 0x08); // 1000
  65 define('MESSAGE_FORCED', 0x0c); // 1100
  66
  67 define('MESSAGE_PERMITTED_MASK', 0x0c); // 1100
  68
  69 /**
  70  * Set default value for default outputs permitted setting
  71  */
  72 define('MESSAGE_DEFAULT_PERMITTED', 'permitted');
  73
  74 /**
  75  * Print the selector that allows the user to view their contacts, course participants, their recent
  76  * conversations etc
  77  *
  78  * @param int $countunreadtotal how many unread messages does the user have?
  79  * @param int $viewing What is the user viewing? ie MESSAGE_VIEW_UNREAD_MESSAGES, MESSAGE_VIEW_SEARCH etc
  80  * @param object $user1 the user whose messages are being viewed
  81  * @param object $user2 the user $user1 is talking to
  82  * @param array $blockedusers an array of users blocked by $user1
  83  * @param array $onlinecontacts an array of $user1's online contacts
  84  * @param array $offlinecontacts an array of $user1's offline contacts
  85  * @param array $strangers an array of users who have messaged $user1 who aren't contacts
  86  * @param bool $showactionlinks show action links (add/remove contact etc)
  87  * @param int $page if there are so many users listed that they have to be split into pages what page are we viewing
  88  * @return void
  89  */
  90 function message_print_contact_selector($countunreadtotal, $viewing, $user1, $user2, $blockedusers, $onlinecontacts, $offlinecontacts, $strangers, $showactionlinks, $page=0) {
  91     global $PAGE;
  92
  93     echo html_writer::start_tag('div', array('class' => 'contactselector mdl-align'));
  94
  95     //if 0 unread messages and they've requested unread messages then show contacts
  96     if ($countunreadtotal == 0 && $viewing == MESSAGE_VIEW_UNREAD_MESSAGES) {
  97         $viewing = MESSAGE_VIEW_CONTACTS;
  98     }
  99
 100     //if they have no blocked users and they've requested blocked users switch them over to contacts
 101     if (count($blockedusers) == 0 && $viewing == MESSAGE_VIEW_BLOCKED) {
 102         $viewing = MESSAGE_VIEW_CONTACTS;
 103     }
 104
 105     $onlyactivecourses = true;
 106     $courses = enrol_get_users_courses($user1->id, $onlyactivecourses);
 107     $coursecontexts = message_get_course_contexts($courses);//we need one of these again so holding on to them
 108
 109     $strunreadmessages = null;
 110     if ($countunreadtotal>0) { //if there are unread messages
 111         $strunreadmessages = get_string('unreadmessages','message', $countunreadtotal);
 112     }
 113
 114     message_print_usergroup_selector($viewing, $courses, $coursecontexts, $countunreadtotal, count($blockedusers), $strunreadmessages, $user1);
 115
 116     if ($viewing == MESSAGE_VIEW_UNREAD_MESSAGES) {
 117         message_print_contacts($onlinecontacts, $offlinecontacts, $strangers, $PAGE->url, 1, $showactionlinks,$strunreadmessages, $user2);
 118     } else if ($viewing == MESSAGE_VIEW_CONTACTS || $viewing == MESSAGE_VIEW_SEARCH || $viewing == MESSAGE_VIEW_RECENT_CONVERSATIONS || $viewing == MESSAGE_VIEW_RECENT_NOTIFICATIONS) {
 119         message_print_contacts($onlinecontacts, $offlinecontacts, $strangers, $PAGE->url, 0, $showactionlinks, $strunreadmessages, $user2);
 120     } else if ($viewing == MESSAGE_VIEW_BLOCKED) {
 121         message_print_blocked_users($blockedusers, $PAGE->url, $showactionlinks, null, $user2);
 122     } else if (substr($viewing, 0, 7) == MESSAGE_VIEW_COURSE) {
 123         $courseidtoshow = intval(substr($viewing, 7));
 124
 125         if (!empty($courseidtoshow)
 126             && array_key_exists($courseidtoshow, $coursecontexts)
 127             && has_capability('moodle/course:viewparticipants', $coursecontexts[$courseidtoshow])) {
 128
 129             message_print_participants($coursecontexts[$courseidtoshow], $courseidtoshow, $PAGE->url, $showactionlinks, null, $page, $user2);
 130         } else {
 131             //shouldn't get here. User trying to access a course they're not in perhaps.
 132             add_to_log(SITEID, 'message', 'view', 'index.php', $viewing);
 133         }
 134     }
 135
 136     // Only show the search button if we're viewing our own messages.
 137     // Search isn't currently able to deal with user A wanting to search user B's messages.
 138     if ($showactionlinks) {
 139         echo html_writer::start_tag('form', array('action' => 'index.php','method' => 'GET'));
 140         echo html_writer::start_tag('fieldset');
 141         $managebuttonclass = 'visible';
 142         if ($viewing == MESSAGE_VIEW_SEARCH) {
 143             $managebuttonclass = 'hiddenelement';
 144         }
 145         $strmanagecontacts = get_string('search','message');
 146         echo html_writer::empty_tag('input', array('type' => 'hidden','name' => 'viewing','value' => MESSAGE_VIEW_SEARCH));
 147         echo html_writer::empty_tag('input', array('type' => 'submit','value' => $strmanagecontacts,'class' => $managebuttonclass));
 148         echo html_writer::end_tag('fieldset');
 149         echo html_writer::end_tag('form');
 150     }
 151
 152     echo html_writer::end_tag('div');
 153 }
 154
 155 /**
 156  * Print course participants. Called by message_print_contact_selector()
 157  *
 158  * @param object $context the course context
 159  * @param int $courseid the course ID
 160  * @param string $contactselecturl the url to send the user to when a contact's name is clicked
 161  * @param bool $showactionlinks show action links (add/remove contact etc) next to the users
 162  * @param string $titletodisplay Optionally specify a title to display above the participants
 163  * @param int $page if there are so many users listed that they have to be split into pages what page are we viewing
 164  * @param object $user2 the user $user1 is talking to. They will be highlighted if they appear in the list of participants
 165  * @return void
 166  */
 167 function message_print_participants($context, $courseid, $contactselecturl=null, $showactionlinks=true, $titletodisplay=null, $page=0, $user2=null) {
 168     global $DB, $USER, $PAGE, $OUTPUT;
 169
 170     if (empty($titletodisplay)) {
 171         $titletodisplay = get_string('participants');
 172     }
 173
 174     $countparticipants = count_enrolled_users($context);
 175
 176     list($esql, $params) = get_enrolled_sql($context);
 177     $params['mcuserid'] = $USER->id;
 178     $ufields = user_picture::fields('u');
 179
 180     $sql = "SELECT $ufields, mc.id as contactlistid, mc.blocked
 181               FROM {user} u
 182               JOIN ($esql) je ON je.id = u.id
 183               LEFT JOIN {message_contacts} mc ON mc.contactid = u.id AND mc.userid = :mcuserid
 184              WHERE u.deleted = 0";
 185
 186     $participants = $DB->get_records_sql($sql, $params, $page * MESSAGE_CONTACTS_PER_PAGE, MESSAGE_CONTACTS_PER_PAGE);
 187
 188     $pagingbar = new paging_bar($countparticipants, $page, MESSAGE_CONTACTS_PER_PAGE, $PAGE->url, 'page');
 189     echo $OUTPUT->render($pagingbar);
 190
 191     echo html_writer::start_tag('table', array('id' => 'message_participants', 'class' => 'boxaligncenter', 'cellspacing' => '2', 'cellpadding' => '0', 'border' => '0'));
 192
 193     echo html_writer::start_tag('tr');
 194     echo html_writer::tag('td', $titletodisplay, array('colspan' => 3, 'class' => 'heading'));
 195     echo html_writer::end_tag('tr');
 196
 197     foreach ($participants as $participant) {
 198         if ($participant->id != $USER->id) {
 199
 200             $iscontact = false;
 201             $isblocked = false;
 202             if ( $participant->contactlistid )  {
 203                 if ($participant->blocked == 0) {
 204                     // Is contact. Is not blocked.
 205                     $iscontact = true;
 206                     $isblocked = false;
 207                 } else {
 208                     // Is blocked.
 209                     $iscontact = false;
 210                     $isblocked = true;
 211                 }
 212             }
 213
 214             $participant->messagecount = 0;//todo it would be nice if the course participant could report new messages
 215             message_print_contactlist_user($participant, $iscontact, $isblocked, $contactselecturl, $showactionlinks, $user2);
 216         }
 217     }
 218
 219     echo html_writer::end_tag('table');
 220 }
 221
 222 /**
 223  * Retrieve users blocked by $user1
 224  *
 225  * @param object $user1 the user whose messages are being viewed
 226  * @param object $user2 the user $user1 is talking to. If they are being blocked
 227  *                      they will have a variable called 'isblocked' added to their user object
 228  * @return array the users blocked by $user1
 229  */
 230 function message_get_blocked_users($user1=null, $user2=null) {
 231     global $DB, $USER;
 232
 233     if (empty($user1)) {
 234         $user1 = $USER;
 235     }
 236
 237     if (!empty($user2)) {
 238         $user2->isblocked = false;
 239     }
 240
 241     $blockedusers = array();
 242
 243     $userfields = user_picture::fields('u', array('lastaccess'));
 244     $blockeduserssql = "SELECT $userfields, COUNT(m.id) AS messagecount
 245                           FROM {message_contacts} mc
 246                           JOIN {user} u ON u.id = mc.contactid
 247                           LEFT OUTER JOIN {message} m ON m.useridfrom = mc.contactid AND m.useridto = :user1id1
 248                          WHERE mc.userid = :user1id2 AND mc.blocked = 1
 249                       GROUP BY $userfields
 250                       ORDER BY u.firstname ASC";
 251     $rs =  $DB->get_recordset_sql($blockeduserssql, array('user1id1' => $user1->id, 'user1id2' => $user1->id));
 252
 253     foreach($rs as $rd) {
 254         $blockedusers[] = $rd;
 255
 256         if (!empty($user2) && $user2->id == $rd->id) {
 257             $user2->isblocked = true;
 258         }
 259     }
 260     $rs->close();
 261
 262     return $blockedusers;
 263 }
 264
 265 /**
 266  * Print users blocked by $user1. Called by message_print_contact_selector()
 267  *
 268  * @param array $blockedusers the users blocked by $user1
 269  * @param string $contactselecturl the url to send the user to when a contact's name is clicked
 270  * @param bool $showactionlinks show action links (add/remove contact etc) next to the users
 271  * @param string $titletodisplay Optionally specify a title to display above the participants
 272  * @param object $user2 the user $user1 is talking to. They will be highlighted if they appear in the list of blocked users
 273  * @return void
 274  */
 275 function message_print_blocked_users($blockedusers, $contactselecturl=null, $showactionlinks=true, $titletodisplay=null, $user2=null) {
 276     global $DB, $USER;
 277
 278     $countblocked = count($blockedusers);
 279
 280     echo html_writer::start_tag('table', array('id' => 'message_contacts', 'class' => 'boxaligncenter'));
 281
 282     if (!empty($titletodisplay)) {
 283         echo html_writer::start_tag('tr');
 284         echo html_writer::tag('td', $titletodisplay, array('colspan' => 3, 'class' => 'heading'));
 285         echo html_writer::end_tag('tr');
 286     }
 287
 288     if ($countblocked) {
 289         echo html_writer::start_tag('tr');
 290         echo html_writer::tag('td', get_string('blockedusers', 'message', $countblocked), array('colspan' => 3, 'class' => 'heading'));
 291         echo html_writer::end_tag('tr');
 292
 293         $isuserblocked = true;
 294         $isusercontact = false;
 295         foreach ($blockedusers as $blockeduser) {
 296             message_print_contactlist_user($blockeduser, $isusercontact, $isuserblocked, $contactselecturl, $showactionlinks, $user2);
 297         }
 298     }
 299
 300     echo html_writer::end_tag('table');
 301 }
 302
 303 /**
 304  * Retrieve $user1's contacts (online, offline and strangers)
 305  *
 306  * @param object $user1 the user whose messages are being viewed
 307  * @param object $user2 the user $user1 is talking to. If they are a contact
 308  *                      they will have a variable called 'iscontact' added to their user object
 309  * @return array containing 3 arrays. array($onlinecontacts, $offlinecontacts, $strangers)
 310  */
 311 function message_get_contacts($user1=null, $user2=null) {
 312     global $DB, $CFG, $USER;
 313
 314     if (empty($user1)) {
 315         $user1 = $USER;
 316     }
 317
 318     if (!empty($user2)) {
 319         $user2->iscontact = false;
 320     }
 321
 322     $timetoshowusers = 300; //Seconds default
 323     if (isset($CFG->block_online_users_timetosee)) {
 324         $timetoshowusers = $CFG->block_online_users_timetosee * 60;
 325     }
 326
 327     // time which a user is counting as being active since
 328     $timefrom = time()-$timetoshowusers;
 329
 330     // people in our contactlist who are online
 331     $onlinecontacts  = array();
 332     // people in our contactlist who are offline
 333     $offlinecontacts = array();
 334     // people who are not in our contactlist but have sent us a message
 335     $strangers       = array();
 336
 337     $userfields = user_picture::fields('u', array('lastaccess'));
 338
 339     // get all in our contactlist who are not blocked in our contact list
 340     // and count messages we have waiting from each of them
 341     $contactsql = "SELECT $userfields, COUNT(m.id) AS messagecount
 342                      FROM {message_contacts} mc
 343                      JOIN {user} u ON u.id = mc.contactid
 344                      LEFT OUTER JOIN {message} m ON m.useridfrom = mc.contactid AND m.useridto = ?
 345                     WHERE mc.userid = ? AND mc.blocked = 0
 346                  GROUP BY $userfields
 347                  ORDER BY u.firstname ASC";
 348
 349     $rs = $DB->get_recordset_sql($contactsql, array($user1->id, $user1->id));
 350     foreach ($rs as $rd) {
 351         if ($rd->lastaccess >= $timefrom) {
 352             // they have been active recently, so are counted online
 353             $onlinecontacts[] = $rd;
 354
 355         } else {
 356             $offlinecontacts[] = $rd;
 357         }
 358
 359         if (!empty($user2) && $user2->id == $rd->id) {
 360             $user2->iscontact = true;
 361         }
 362     }
 363     $rs->close();
 364
 365     // get messages from anyone who isn't in our contact list and count the number
 366     // of messages we have from each of them
 367     $strangersql = "SELECT $userfields, count(m.id) as messagecount
 368                       FROM {message} m
 369                       JOIN {user} u  ON u.id = m.useridfrom
 370                       LEFT OUTER JOIN {message_contacts} mc ON mc.contactid = m.useridfrom AND mc.userid = m.useridto
 371                      WHERE mc.id IS NULL AND m.useridto = ?
 372                   GROUP BY $userfields
 373                   ORDER BY u.firstname ASC";
 374
 375     $rs = $DB->get_recordset_sql($strangersql, array($USER->id));
 376     foreach ($rs as $rd) {
 377         $strangers[] = $rd;
 378     }
 379     $rs->close();
 380
 381     return array($onlinecontacts, $offlinecontacts, $strangers);
 382 }
 383
 384 /**
 385  * Print $user1's contacts. Called by message_print_contact_selector()
 386  *
 387  * @param array $onlinecontacts $user1's contacts which are online
 388  * @param array $offlinecontacts $user1's contacts which are offline
 389  * @param array $strangers users which are not contacts but who have messaged $user1
 390  * @param string $contactselecturl the url to send the user to when a contact's name is clicked
 391  * @param int $minmessages The minimum number of unread messages required from a user for them to be displayed
 392  *                         Typically 0 (show all contacts) or 1 (only show contacts from whom we have a new message)
 393  * @param bool $showactionlinks show action links (add/remove contact etc) next to the users
 394  * @param string $titletodisplay Optionally specify a title to display above the participants
 395  * @param object $user2 the user $user1 is talking to. They will be highlighted if they appear in the list of contacts
 396  * @return void
 397  */
 398 function message_print_contacts($onlinecontacts, $offlinecontacts, $strangers, $contactselecturl=null, $minmessages=0, $showactionlinks=true, $titletodisplay=null, $user2=null) {
 399     global $CFG, $PAGE, $OUTPUT;
 400
 401     $countonlinecontacts  = count($onlinecontacts);
 402     $countofflinecontacts = count($offlinecontacts);
 403     $countstrangers       = count($strangers);
 404     $isuserblocked = null;
 405
 406     if ($countonlinecontacts + $countofflinecontacts == 0) {
 407         echo html_writer::tag('div', get_string('contactlistempty', 'message'), array('class' => 'heading'));
 408     }
 409
 410     echo html_writer::start_tag('table', array('id' => 'message_contacts', 'class' => 'boxaligncenter'));
 411
 412     if (!empty($titletodisplay)) {
 413         message_print_heading($titletodisplay);
 414     }
 415
 416     if($countonlinecontacts) {
 417         // Print out list of online contacts.
 418
 419         if (empty($titletodisplay)) {
 420             message_print_heading(get_string('onlinecontacts', 'message', $countonlinecontacts));
 421         }
 422
 423         $isuserblocked = false;
 424         $isusercontact = true;
 425         foreach ($onlinecontacts as $contact) {
 426             if ($minmessages == 0 || $contact->messagecount >= $minmessages) {
 427                 message_print_contactlist_user($contact, $isusercontact, $isuserblocked, $contactselecturl, $showactionlinks, $user2);
 428             }
 429         }
 430     }
 431
 432     if ($countofflinecontacts) {
 433         // Print out list of offline contacts.
 434
 435         if (empty($titletodisplay)) {
 436             message_print_heading(get_string('offlinecontacts', 'message', $countofflinecontacts));
 437         }
 438
 439         $isuserblocked = false;
 440         $isusercontact = true;
 441         foreach ($offlinecontacts as $contact) {
 442             if ($minmessages == 0 || $contact->messagecount >= $minmessages) {
 443                 message_print_contactlist_user($contact, $isusercontact, $isuserblocked, $contactselecturl, $showactionlinks, $user2);
 444             }
 445         }
 446
 447     }
 448
 449     // Print out list of incoming contacts.
 450     if ($countstrangers) {
 451         message_print_heading(get_string('incomingcontacts', 'message', $countstrangers));
 452
 453         $isuserblocked = false;
 454         $isusercontact = false;
 455         foreach ($strangers as $stranger) {
 456             if ($minmessages == 0 || $stranger->messagecount >= $minmessages) {
 457                 message_print_contactlist_user($stranger, $isusercontact, $isuserblocked, $contactselecturl, $showactionlinks, $user2);
 458             }
 459         }
 460     }
 461
 462     echo html_writer::end_tag('table');
 463
 464     if ($countstrangers && ($countonlinecontacts + $countofflinecontacts == 0)) {  // Extra help
 465         echo html_writer::tag('div','('.get_string('addsomecontactsincoming', 'message').')',array('class' => 'note'));
 466     }
 467 }
 468
 469 /**
 470  * Print a select box allowing the user to choose to view new messages, course participants etc.
 471  *
 472  * Called by message_print_contact_selector()
 473  * @param int $viewing What page is the user viewing ie MESSAGE_VIEW_UNREAD_MESSAGES, MESSAGE_VIEW_RECENT_CONVERSATIONS etc
 474  * @param array $courses array of course objects. The courses the user is enrolled in.
 475  * @param array $coursecontexts array of course contexts. Keyed on course id.
 476  * @param int $countunreadtotal how many unread messages does the user have?
 477  * @param int $countblocked how many users has the current user blocked?
 478  * @param stdClass $user1 The user whose messages we are viewing.
 479  * @param string $strunreadmessages a preconstructed message about the number of unread messages the user has
 480  * @return void
 481  */
 482 function message_print_usergroup_selector($viewing, $courses, $coursecontexts, $countunreadtotal, $countblocked, $strunreadmessages, $user1 = null) {
 483     $options = array();
 484
 485     if ($countunreadtotal>0) { //if there are unread messages
 486         $options[MESSAGE_VIEW_UNREAD_MESSAGES] = $strunreadmessages;
 487     }
 488
 489     $str = get_string('contacts', 'message');
 490     $options[MESSAGE_VIEW_CONTACTS] = $str;
 491
 492     $options[MESSAGE_VIEW_RECENT_CONVERSATIONS] = get_string('mostrecentconversations', 'message');
 493     $options[MESSAGE_VIEW_RECENT_NOTIFICATIONS] = get_string('mostrecentnotifications', 'message');
 494
 495     if (!empty($courses)) {
 496         $courses_options = array();
 497
 498         foreach($courses as $course) {
 499             if (has_capability('moodle/course:viewparticipants', $coursecontexts[$course->id])) {
 500                 //Not using short_text() as we want the end of the course name. Not the beginning.
 501                 $shortname = format_string($course->shortname, true, array('context' => $coursecontexts[$course->id]));
 502                 if (textlib::strlen($shortname) > MESSAGE_MAX_COURSE_NAME_LENGTH) {
 503                     $courses_options[MESSAGE_VIEW_COURSE.$course->id] = '...'.textlib::substr($shortname, -MESSAGE_MAX_COURSE_NAME_LENGTH);
 504                 } else {
 505                     $courses_options[MESSAGE_VIEW_COURSE.$course->id] = $shortname;
 506                 }
 507             }
 508         }
 509
 510         if (!empty($courses_options)) {
 511             $options[] = array(get_string('courses') => $courses_options);
 512         }
 513     }
 514
 515     if ($countblocked>0) {
 516         $str = get_string('blockedusers','message', $countblocked);
 517         $options[MESSAGE_VIEW_BLOCKED] = $str;
 518     }
 519
 520     echo html_writer::start_tag('form', array('id' => 'usergroupform','method' => 'get','action' => ''));
 521     echo html_writer::start_tag('fieldset');
 522     if ( !empty($user1) && !empty($user1->id) ) {
 523         echo html_writer::empty_tag('input', array('type' => 'hidden','name' => 'user1','value' => $user1->id));
 524     }
 525     echo html_writer::label(get_string('messagenavigation', 'message'), 'viewing');
 526     echo html_writer::select($options, 'viewing', $viewing, false, array('id' => 'viewing','onchange' => 'this.form.submit()'));
 527     echo html_writer::end_tag('fieldset');
 528     echo html_writer::end_tag('form');
 529 }
 530
 531 /**
 532  * Load the course contexts for all of the users courses
 533  *
 534  * @param array $courses array of course objects. The courses the user is enrolled in.
 535  * @return array of course contexts
 536  */
 537 function message_get_course_contexts($courses) {
 538     $coursecontexts = array();
 539
 540     foreach($courses as $course) {
 541         $coursecontexts[$course->id] = context_course::instance($course->id);
 542     }
 543
 544     return $coursecontexts;
 545 }
 546
 547 /**
 548  * strip off action parameters like 'removecontact'
 549  *
 550  * @param moodle_url/string $moodleurl a URL. Typically the current page URL.
 551  * @return string the URL minus parameters that perform actions (like adding/removing/blocking a contact).
 552  */
 553 function message_remove_url_params($moodleurl) {
 554     $newurl = new moodle_url($moodleurl);
 555     $newurl->remove_params('addcontact','removecontact','blockcontact','unblockcontact');
 556     return $newurl->out();
 557 }
 558
 559 /**
 560  * Count the number of messages with a field having a specified value.
 561  * if $field is empty then return count of the whole array
 562  * if $field is non-existent then return 0
 563  *
 564  * @param array $messagearray array of message objects
 565  * @param string $field the field to inspect on the message objects
 566  * @param string $value the value to test the field against
 567  */
 568 function message_count_messages($messagearray, $field='', $value='') {
 569     if (!is_array($messagearray)) return 0;
 570     if ($field == '' or empty($messagearray)) return count($messagearray);
 571
 572     $count = 0;
 573     foreach ($messagearray as $message) {
 574         $count += ($message->$field == $value) ? 1 : 0;
 575     }
 576     return $count;
 577 }
 578
 579 /**
 580  * Returns the count of unread messages for user. Either from a specific user or from all users.
 581  *
 582  * @param object $user1 the first user. Defaults to $USER
 583  * @param object $user2 the second user. If null this function will count all of user 1's unread messages.
 584  * @return int the count of $user1's unread messages
 585  */
 586 function message_count_unread_messages($user1=null, $user2=null) {
 587     global $USER, $DB;
 588
 589     if (empty($user1)) {
 590         $user1 = $USER;
 591     }
 592
 593     if (!empty($user2)) {
 594         return $DB->count_records_select('message', "useridto = ? AND useridfrom = ?",
 595             array($user1->id, $user2->id), "COUNT('id')");
 596     } else {
 597         return $DB->count_records_select('message', "useridto = ?",
 598             array($user1->id), "COUNT('id')");
 599     }
 600 }
 601
 602 /**
 603  * Count the number of users blocked by $user1
 604  *
 605  * @param object $user1 user object
 606  * @return int the number of blocked users
 607  */
 608 function message_count_blocked_users($user1=null) {
 609     global $USER, $DB;
 610
 611     if (empty($user1)) {
 612         $user1 = $USER;
 613     }
 614
 615     $sql = "SELECT count(mc.id)
 616             FROM {message_contacts} mc
 617             WHERE mc.userid = :userid AND mc.blocked = 1";
 618     $params = array('userid' => $user1->id);
 619
 620     return $DB->count_records_sql($sql, $params);
 621 }
 622
 623 /**
 624  * Print the search form and search results if a search has been performed
 625  *
 626  * @param  boolean $advancedsearch show basic or advanced search form
 627  * @param  object $user1 the current user
 628  * @return boolean true if a search was performed
 629  */
 630 function message_print_search($advancedsearch = false, $user1=null) {
 631     $frm = data_submitted();
 632
 633     $doingsearch = false;
 634     if ($frm) {
 635         if (confirm_sesskey()) {
 636             $doingsearch = !empty($frm->combinedsubmit) || !empty($frm->keywords) || (!empty($frm->personsubmit) and !empty($frm->name));
 637         } else {
 638             $frm = false;
 639         }
 640     }
 641
 642     if (!empty($frm->combinedsearch)) {
 643         $combinedsearchstring = $frm->combinedsearch;
 644     } else {
 645         //$combinedsearchstring = get_string('searchcombined','message').'...';
 646         $combinedsearchstring = '';
 647     }
 648
 649     if ($doingsearch) {
 650         if ($advancedsearch) {
 651
 652             $messagesearch = '';
 653             if (!empty($frm->keywords)) {
 654                 $messagesearch = $frm->keywords;
 655             }
 656             $personsearch = '';
 657             if (!empty($frm->name)) {
 658                 $personsearch = $frm->name;
 659             }
 660             include('search_advanced.html');
 661         } else {
 662             include('search.html');
 663         }
 664
 665         $showicontext = false;
 666         message_print_search_results($frm, $showicontext, $user1);
 667
 668         return true;
 669     } else {
 670
 671         if ($advancedsearch) {
 672             $personsearch = $messagesearch = '';
 673             include('search_advanced.html');
 674         } else {
 675             include('search.html');
 676         }
 677         return false;
 678     }
 679 }
 680
 681 /**
 682  * Get the users recent conversations meaning all the people they've recently
 683  * sent or received a message from plus the most recent message sent to or received from each other user
 684  *
 685  * @param object $user the current user
 686  * @param int $limitfrom can be used for paging
 687  * @param int $limitto can be used for paging
 688  * @return array
 689  */
 690 function message_get_recent_conversations($user, $limitfrom=0, $limitto=100) {
 691     global $DB;
 692
 693     $userfields = user_picture::fields('u', array('lastaccess'));
 694     //This query retrieves the last message received from and sent to each user
 695     //It unions that data then, within that set, it finds the most recent message you've exchanged with each user over all
 696     //It then joins with some other tables to get some additional data we need
 697
 698     //message ID is used instead of timecreated as it should sort the same and will be much faster
 699
 700     //There is a separate query for read and unread queries as they are stored in different tables
 701     //They were originally retrieved in one query but it was so large that it was difficult to be confident in its correctness
 702     $sql = "SELECT $userfields, mr.id as mid, mr.smallmessage, mr.fullmessage, mr.timecreated, mc.id as contactlistid, mc.blocked
 703               FROM {message_read} mr
 704               JOIN (
 705                     SELECT messages.userid AS userid, MAX(messages.mid) AS mid
 706                       FROM (
 707                            SELECT mr1.useridto AS userid, MAX(mr1.id) AS mid
 708                              FROM {message_read} mr1
 709                             WHERE mr1.useridfrom = :userid1
 710                                   AND mr1.notification = 0
 711                          GROUP BY mr1.useridto
 712                                   UNION
 713                            SELECT mr2.useridfrom AS userid, MAX(mr2.id) AS mid
 714                              FROM {message_read} mr2
 715                             WHERE mr2.useridto = :userid2
 716                                   AND mr2.notification = 0
 717                          GROUP BY mr2.useridfrom
 718                            ) messages
 719                   GROUP BY messages.userid
 720                    ) messages2 ON mr.id = messages2.mid AND (mr.useridto = messages2.userid OR mr.useridfrom = messages2.userid)
 721               JOIN {user} u ON u.id = messages2.userid
 722          LEFT JOIN {message_contacts} mc ON mc.userid = :userid3 AND mc.contactid = u.id
 723              WHERE u.deleted = '0'
 724           ORDER BY mr.id DESC";
 725     $params = array('userid1' => $user->id, 'userid2' => $user->id, 'userid3' => $user->id);
 726     $read =  $DB->get_records_sql($sql, $params, $limitfrom, $limitto);
 727
 728     $sql = "SELECT $userfields, m.id as mid, m.smallmessage, m.fullmessage, m.timecreated, mc.id as contactlistid, mc.blocked
 729               FROM {message} m
 730               JOIN (
 731                     SELECT messages.userid AS userid, MAX(messages.mid) AS mid
 732                       FROM (
 733                            SELECT m1.useridto AS userid, MAX(m1.id) AS mid
 734                              FROM {message} m1
 735                             WHERE m1.useridfrom = :userid1
 736                                   AND m1.notification = 0
 737                          GROUP BY m1.useridto
 738                                   UNION
 739                            SELECT m2.useridfrom AS userid, MAX(m2.id) AS mid
 740                              FROM {message} m2
 741                             WHERE m2.useridto = :userid2
 742                                   AND m2.notification = 0
 743                          GROUP BY m2.useridfrom
 744                            ) messages
 745                   GROUP BY messages.userid
 746                    ) messages2 ON m.id = messages2.mid AND (m.useridto = messages2.userid OR m.useridfrom = messages2.userid)
 747               JOIN {user} u ON u.id = messages2.userid
 748          LEFT JOIN {message_contacts} mc ON mc.userid = :userid3 AND mc.contactid = u.id
 749              WHERE u.deleted = '0'
 750              ORDER BY m.id DESC";
 751     $unread =  $DB->get_records_sql($sql, $params, $limitfrom, $limitto);
 752
 753     $conversations = array();
 754
 755     //Union the 2 result sets together looking for the message with the most recent timecreated for each other user
 756     //$conversation->id (the array key) is the other user's ID
 757     $conversation_arrays = array($unread, $read);
 758     foreach ($conversation_arrays as $conversation_array) {
 759         foreach ($conversation_array as $conversation) {
 760             if (empty($conversations[$conversation->id]) || $conversations[$conversation->id]->timecreated < $conversation->timecreated ) {
 761                 $conversations[$conversation->id] = $conversation;
 762             }
 763         }
 764     }
 765
 766     // Sort the conversations by $conversation->timecreated, newest to oldest
 767     // There may be multiple conversations with the same timecreated
 768     // The conversations array contains both read and unread messages (different tables) so sorting by ID won't work
 769     $result = collatorlib::asort_objects_by_property($conversations, 'timecreated', collatorlib::SORT_NUMERIC);
 770     $conversations = array_reverse($conversations);
 771
 772     return $conversations;
 773 }
 774
 775 /**
 776  * Get the users recent event notifications
 777  *
 778  * @param object $user the current user
 779  * @param int $limitfrom can be used for paging
 780  * @param int $limitto can be used for paging
 781  * @return array
 782  */
 783 function message_get_recent_notifications($user, $limitfrom=0, $limitto=100) {
 784     global $DB;
 785
 786     $userfields = user_picture::fields('u', array('lastaccess'));
 787     $sql = "SELECT mr.id AS message_read_id, $userfields, mr.smallmessage, mr.fullmessage, mr.timecreated as timecreated, mr.contexturl, mr.contexturlname
 788               FROM {message_read} mr
 789                    JOIN {user} u ON u.id=mr.useridfrom
 790              WHERE mr.useridto = :userid1 AND u.deleted = '0' AND mr.notification = :notification
 791              ORDER BY mr.id DESC";//ordering by id should give the same result as ordering by timecreated but will be faster
 792     $params = array('userid1' => $user->id, 'notification' => 1);
 793
 794     $notifications =  $DB->get_records_sql($sql, $params, $limitfrom, $limitto);
 795     return $notifications;
 796 }
 797
 798 /**
 799  * Print the user's recent conversations
 800  *
 801  * @param stdClass $user the current user
 802  * @param bool $showicontext flag indicating whether or not to show text next to the action icons
 803  */
 804 function message_print_recent_conversations($user1 = null, $showicontext = false, $showactionlinks = true) {
 805     global $USER;
 806
 807     echo html_writer::start_tag('p', array('class' => 'heading'));
 808     echo get_string('mostrecentconversations', 'message');
 809     echo html_writer::end_tag('p');
 810
 811     if (empty($user1)) {
 812         $user1 = $USER;
 813     }
 814
 815     $conversations = message_get_recent_conversations($user1);
 816
 817     // Attach context url information to create the "View this conversation" type links
 818     foreach($conversations as $conversation) {
 819         $conversation->contexturl = new moodle_url("/message/index.php?user1={$user1->id}&user2={$conversation->id}");
 820         $conversation->contexturlname = get_string('thisconversation', 'message');
 821     }
 822
 823     $showotheruser = true;
 824     message_print_recent_messages_table($conversations, $user1, $showotheruser, $showicontext, false, $showactionlinks);
 825 }
 826
 827 /**
 828  * Print the user's recent notifications
 829  *
 830  * @param stdClass $user the current user
 831  */
 832 function message_print_recent_notifications($user=null) {
 833     global $USER;
 834
 835     echo html_writer::start_tag('p', array('class' => 'heading'));
 836     echo get_string('mostrecentnotifications', 'message');
 837     echo html_writer::end_tag('p');
 838
 839     if (empty($user)) {
 840         $user = $USER;
 841     }
 842
 843     $notifications = message_get_recent_notifications($user);
 844
 845     $showicontext = false;
 846     $showotheruser = false;
 847     message_print_recent_messages_table($notifications, $user, $showotheruser, $showicontext, true);
 848 }
 849
 850 /**
 851  * Print a list of recent messages
 852  *
 853  * @param array $messages the messages to display
 854  * @param object $user the current user
 855  * @param bool $showotheruser display information on the other user?
 856  * @param bool $showicontext show text next to the action icons?
 857  * @param bool $forcetexttohtml Force text to go through @see text_to_html() via @see format_text()
 858  * @return void
 859  */
 860 function message_print_recent_messages_table($messages, $user = null, $showotheruser = true, $showicontext = false, $forcetexttohtml = false, $showactionlinks = true) {
 861     global $OUTPUT;
 862     static $dateformat;
 863
 864     if (empty($dateformat)) {
 865         $dateformat = get_string('strftimedatetimeshort');
 866     }
 867
 868     echo html_writer::start_tag('div', array('class' => 'messagerecent'));
 869     foreach ($messages as $message) {
 870         echo html_writer::start_tag('div', array('class' => 'singlemessage'));
 871
 872         if ($showotheruser) {
 873             $strcontact = $strblock = $strhistory = null;
 874
 875             if ($showactionlinks) {
 876                 if ( $message->contactlistid )  {
 877                     if ($message->blocked == 0) { // The other user isn't blocked.
 878                         $strcontact = message_contact_link($message->id, 'remove', true, null, $showicontext);
 879                         $strblock   = message_contact_link($message->id, 'block', true, null, $showicontext);
 880                     } else { // The other user is blocked.
 881                         $strcontact = message_contact_link($message->id, 'add', true, null, $showicontext);
 882                         $strblock   = message_contact_link($message->id, 'unblock', true, null, $showicontext);
 883                     }
 884                 } else {
 885                     $strcontact = message_contact_link($message->id, 'add', true, null, $showicontext);
 886                     $strblock   = message_contact_link($message->id, 'block', true, null, $showicontext);
 887                 }
 888
 889                 //should we show just the icon or icon and text?
 890                 $histicontext = 'icon';
 891                 if ($showicontext) {
 892                     $histicontext = 'both';
 893                 }
 894                 $strhistory = message_history_link($user->id, $message->id, true, '', '', $histicontext);
 895             }
 896             echo html_writer::start_tag('span', array('class' => 'otheruser'));
 897
 898             echo html_writer::start_tag('span', array('class' => 'pix'));
 899             echo $OUTPUT->user_picture($message, array('size' => 20, 'courseid' => SITEID));
 900             echo html_writer::end_tag('span');
 901
 902             echo html_writer::start_tag('span', array('class' => 'contact'));
 903
 904             $link = new moodle_url("/message/index.php?user1={$user->id}&user2=$message->id");
 905             $action = null;
 906             echo $OUTPUT->action_link($link, fullname($message), $action, array('title' => get_string('sendmessageto', 'message', fullname($message))));
 907
 908             echo html_writer::end_tag('span');//end contact
 909
 910             if ($showactionlinks) {
 911                 echo $strcontact.$strblock.$strhistory;
 912             }
 913             echo html_writer::end_tag('span');//end otheruser
 914         }
 915         $messagetoprint = null;
 916         if (!empty($message->smallmessage)) {
 917             $messagetoprint = $message->smallmessage;
 918         } else {
 919             $messagetoprint = $message->fullmessage;
 920         }
 921
 922         echo html_writer::tag('span', userdate($message->timecreated, $dateformat), array('class' => 'messagedate'));
 923         echo html_writer::tag('span', format_text($messagetoprint, $forcetexttohtml?FORMAT_MOODLE:FORMAT_HTML), array('class' => 'themessage'));
 924         echo message_format_contexturl($message);
 925         echo html_writer::end_tag('div');//end singlemessage
 926     }
 927     echo html_writer::end_tag('div');//end messagerecent
 928 }
 929
 930 /**
 931  * Add the selected user as a contact for the current user
 932  *
 933  * @param int $contactid the ID of the user to add as a contact
 934  * @param int $blocked 1 if you wish to block the contact
 935  * @return bool/int false if the $contactid isnt a valid user id. True if no changes made.
 936  *                  Otherwise returns the result of update_record() or insert_record()
 937  */
 938 function message_add_contact($contactid, $blocked=0) {
 939     global $USER, $DB;
 940
 941     if (!$DB->record_exists('user', array('id' => $contactid))) { // invalid userid
 942         return false;
 943     }
 944
 945     if (($contact = $DB->get_record('message_contacts', array('userid' => $USER->id, 'contactid' => $contactid))) !== false) {
 946     // A record already exists. We may be changing blocking status.
 947
 948         if ($contact->blocked !== $blocked) {
 949             // Blocking status has been changed.
 950             $contact->blocked = $blocked;
 951             return $DB->update_record('message_contacts', $contact);
 952         } else {
 953             // No change to blocking status.
 954             return true;
 955         }
 956
 957     } else {
 958         // New contact record.
 959         $contact = new stdClass();
 960         $contact->userid = $USER->id;
 961         $contact->contactid = $contactid;
 962         $contact->blocked = $blocked;
 963         return $DB->insert_record('message_contacts', $contact, false);
 964     }
 965 }
 966
 967 /**
 968  * remove a contact
 969  *
 970  * @param int $contactid the user ID of the contact to remove
 971  * @return bool returns the result of delete_records()
 972  */
 973 function message_remove_contact($contactid) {
 974     global $USER, $DB;
 975     return $DB->delete_records('message_contacts', array('userid' => $USER->id, 'contactid' => $contactid));
 976 }
 977
 978 /**
 979  * Unblock a contact. Note that this reverts the previously blocked user back to a non-contact.
 980  *
 981  * @param int $contactid the user ID of the contact to unblock
 982  * @return bool returns the result of delete_records()
 983  */
 984 function message_unblock_contact($contactid) {
 985     global $USER, $DB;
 986     return $DB->delete_records('message_contacts', array('userid' => $USER->id, 'contactid' => $contactid));
 987 }
 988
 989 /**
 990  * block a user
 991  *
 992  * @param int $contactid the user ID of the user to block
 993  */
 994 function message_block_contact($contactid) {
 995     return message_add_contact($contactid, 1);
 996 }
 997
 998 /**
 999  * Load a user's contact record
1000  *
1001  * @param int $contactid the user ID of the user whose contact record you want
1002  * @return array message contacts
1003  */
1004 function message_get_contact($contactid) {
1005     global $USER, $DB;
1006     return $DB->get_record('message_contacts', array('userid' => $USER->id, 'contactid' => $contactid));
1007 }
1008
1009 /**
1010  * Print the results of a message search
1011  *
1012  * @param mixed $frm submitted form data
1013  * @param bool $showicontext show text next to action icons?
1014  * @param object $currentuser the current user
1015  * @return void
1016  */
1017 function message_print_search_results($frm, $showicontext=false, $currentuser=null) {
1018     global $USER, $DB, $OUTPUT;
1019
1020     if (empty($currentuser)) {
1021         $currentuser = $USER;
1022     }
1023
1024     echo html_writer::start_tag('div', array('class' => 'mdl-left'));
1025
1026     $personsearch = false;
1027     $personsearchstring = null;
1028     if (!empty($frm->personsubmit) and !empty($frm->name)) {
1029         $personsearch = true;
1030         $personsearchstring = $frm->name;
1031     } else if (!empty($frm->combinedsubmit) and !empty($frm->combinedsearch)) {
1032         $personsearch = true;
1033         $personsearchstring = $frm->combinedsearch;
1034     }
1035
1036     // Search for person.
1037     if ($personsearch) {
1038         if (optional_param('mycourses', 0, PARAM_BOOL)) {
1039             $users = array();
1040             $mycourses = enrol_get_my_courses('id');
1041             $mycoursesids = array();
1042             foreach ($mycourses as $mycourse) {
1043                 $mycoursesids[] = $mycourse->id;
1044             }
1045             $susers = message_search_users($mycoursesids, $personsearchstring);
1046             foreach ($susers as $suser) {
1047                 $users[$suser->id] = $suser;
1048             }
1049         } else {
1050             $users = message_search_users(SITEID, $personsearchstring);
1051         }
1052
1053         if (!empty($users)) {
1054             echo html_writer::start_tag('p', array('class' => 'heading searchresultcount'));
1055             echo get_string('userssearchresults', 'message', count($users));
1056             echo html_writer::end_tag('p');
1057
1058             echo html_writer::start_tag('table', array('class' => 'messagesearchresults'));
1059             foreach ($users as $user) {
1060
1061                 if ( $user->contactlistid )  {
1062                     if ($user->blocked == 0) { // User is not blocked.
1063                         $strcontact = message_contact_link($user->id, 'remove', true, null, $showicontext);
1064                         $strblock   = message_contact_link($user->id, 'block', true, null, $showicontext);
1065                     } else { // blocked
1066                         $strcontact = message_contact_link($user->id, 'add', true, null, $showicontext);
1067                         $strblock   = message_contact_link($user->id, 'unblock', true, null, $showicontext);
1068                     }
1069                 } else {
1070                     $strcontact = message_contact_link($user->id, 'add', true, null, $showicontext);
1071                     $strblock   = message_contact_link($user->id, 'block', true, null, $showicontext);
1072                 }
1073
1074                 // Should we show just the icon or icon and text?
1075                 $histicontext = 'icon';
1076                 if ($showicontext) {
1077                     $histicontext = 'both';
1078                 }
1079                 $strhistory = message_history_link($USER->id, $user->id, true, '', '', $histicontext);
1080
1081                 echo html_writer::start_tag('tr');
1082
1083                 echo html_writer::start_tag('td', array('class' => 'pix'));
1084                 echo $OUTPUT->user_picture($user, array('size' => 20, 'courseid' => SITEID));
1085                 echo html_writer::end_tag('td');
1086
1087                 echo html_writer::start_tag('td',array('class' => 'contact'));
1088                 $action = null;
1089                 $link = new moodle_url("/message/index.php?id=$user->id");
1090                 echo $OUTPUT->action_link($link, fullname($user), $action, array('title' => get_string('sendmessageto', 'message', fullname($user))));
1091                 echo html_writer::end_tag('td');
1092
1093                 echo html_writer::tag('td', $strcontact, array('class' => 'link'));
1094                 echo html_writer::tag('td', $strblock, array('class' => 'link'));
1095                 echo html_writer::tag('td', $strhistory, array('class' => 'link'));
1096
1097                 echo html_writer::end_tag('tr');
1098             }
1099             echo html_writer::end_tag('table');
1100
1101         } else {
1102             echo html_writer::start_tag('p', array('class' => 'heading searchresultcount'));
1103             echo get_string('userssearchresults', 'message', 0).'<br /><br />';
1104             echo html_writer::end_tag('p');
1105         }
1106     }
1107
1108     // search messages for keywords
1109     $messagesearch = false;
1110     $messagesearchstring = null;
1111     if (!empty($frm->keywords)) {
1112         $messagesearch = true;
1113         $messagesearchstring = clean_text(trim($frm->keywords));
1114     } else if (!empty($frm->combinedsubmit) and !empty($frm->combinedsearch)) {
1115         $messagesearch = true;
1116         $messagesearchstring = clean_text(trim($frm->combinedsearch));
1117     }
1118
1119     if ($messagesearch) {
1120         if ($messagesearchstring) {
1121             $keywords = explode(' ', $messagesearchstring);
1122         } else {
1123             $keywords = array();
1124         }
1125         $tome     = false;
1126         $fromme   = false;
1127         $courseid = 'none';
1128
1129         if (empty($frm->keywordsoption)) {
1130             $frm->keywordsoption = 'allmine';
1131         }
1132
1133         switch ($frm->keywordsoption) {
1134             case 'tome':
1135                 $tome   = true;
1136                 break;
1137             case 'fromme':
1138                 $fromme = true;
1139                 break;
1140             case 'allmine':
1141                 $tome   = true;
1142                 $fromme = true;
1143                 break;
1144             case 'allusers':
1145                 $courseid = SITEID;
1146                 break;
1147             case 'courseusers':
1148                 $courseid = $frm->courseid;
1149                 break;
1150             default:
1151                 $tome   = true;
1152                 $fromme = true;
1153         }
1154
1155         if (($messages = message_search($keywords, $fromme, $tome, $courseid)) !== false) {
1156
1157             // Get a list of contacts.
1158             if (($contacts = $DB->get_records('message_contacts', array('userid' => $USER->id), '', 'contactid, blocked') ) === false) {
1159                 $contacts = array();
1160             }
1161
1162             // Print heading with number of results.
1163             echo html_writer::start_tag('p', array('class' => 'heading searchresultcount'));
1164             $countresults = count($messages);
1165             if ($countresults == MESSAGE_SEARCH_MAX_RESULTS) {
1166                 echo get_string('keywordssearchresultstoomany', 'message', $countresults).' ("'.s($messagesearchstring).'")';
1167             } else {
1168                 echo get_string('keywordssearchresults', 'message', $countresults);
1169             }
1170             echo html_writer::end_tag('p');
1171
1172             // Print table headings.
1173             echo html_writer::start_tag('table', array('class' => 'messagesearchresults', 'cellspacing' => '0'));
1174
1175             $headertdstart = html_writer::start_tag('td', array('class' => 'messagesearchresultscol'));
1176             $headertdend   = html_writer::end_tag('td');
1177             echo html_writer::start_tag('tr');
1178             echo $headertdstart.get_string('from').$headertdend;
1179             echo $headertdstart.get_string('to').$headertdend;
1180             echo $headertdstart.get_string('message', 'message').$headertdend;
1181             echo $headertdstart.get_string('timesent', 'message').$headertdend;
1182             echo html_writer::end_tag('tr');
1183
1184             $blockedcount = 0;
1185             $dateformat = get_string('strftimedatetimeshort');
1186             $strcontext = get_string('context', 'message');
1187             foreach ($messages as $message) {
1188
1189                 // Ignore messages to and from blocked users unless $frm->includeblocked is set.
1190                 if (!optional_param('includeblocked', 0, PARAM_BOOL) and (
1191                       ( isset($contacts[$message->useridfrom]) and ($contacts[$message->useridfrom]->blocked == 1)) or
1192                       ( isset($contacts[$message->useridto]  ) and ($contacts[$message->useridto]->blocked   == 1))
1193                                                 )
1194                    ) {
1195                     $blockedcount ++;
1196                     continue;
1197                 }
1198
1199                 // Load user-to record.
1200                 if ($message->useridto !== $USER->id) {
1201                     $userto = $DB->get_record('user', array('id' => $message->useridto));
1202                     $tocontact = (array_key_exists($message->useridto, $contacts) and
1203                                     ($contacts[$message->useridto]->blocked == 0) );
1204                     $toblocked = (array_key_exists($message->useridto, $contacts) and
1205                                     ($contacts[$message->useridto]->blocked == 1) );
1206                 } else {
1207                     $userto = false;
1208                     $tocontact = false;
1209                     $toblocked = false;
1210                 }
1211
1212                 // Load user-from record.
1213                 if ($message->useridfrom !== $USER->id) {
1214                     $userfrom = $DB->get_record('user', array('id' => $message->useridfrom));
1215                     $fromcontact = (array_key_exists($message->useridfrom, $contacts) and
1216                                     ($contacts[$message->useridfrom]->blocked == 0) );
1217                     $fromblocked = (array_key_exists($message->useridfrom, $contacts) and
1218                                     ($contacts[$message->useridfrom]->blocked == 1) );
1219                 } else {
1220                     $userfrom = false;
1221                     $fromcontact = false;
1222                     $fromblocked = false;
1223                 }
1224
1225                 // Find date string for this message.
1226                 $date = usergetdate($message->timecreated);
1227                 $datestring = $date['year'].$date['mon'].$date['mday'];
1228
1229                 // Print out message row.
1230                 echo html_writer::start_tag('tr', array('valign' => 'top'));
1231
1232                 echo html_writer::start_tag('td', array('class' => 'contact'));
1233                 message_print_user($userfrom, $fromcontact, $fromblocked, $showicontext);
1234                 echo html_writer::end_tag('td');
1235
1236                 echo html_writer::start_tag('td', array('class' => 'contact'));
1237                 message_print_user($userto, $tocontact, $toblocked, $showicontext);
1238                 echo html_writer::end_tag('td');
1239
1240                 echo html_writer::start_tag('td', array('class' => 'summary'));
1241                 echo message_get_fragment($message->smallmessage, $keywords);
1242                 echo html_writer::start_tag('div', array('class' => 'link'));
1243
1244                 // If the user clicks the context link display message sender on the left.
1245                 // EXCEPT if the current user is in the conversation. Current user == always on the left.
1246                 $leftsideuserid = $rightsideuserid = null;
1247                 if ($currentuser->id == $message->useridto) {
1248                     $leftsideuserid = $message->useridto;
1249                     $rightsideuserid = $message->useridfrom;
1250                 } else {
1251                     $leftsideuserid = $message->useridfrom;
1252                     $rightsideuserid = $message->useridto;
1253                 }
1254                 message_history_link($leftsideuserid, $rightsideuserid, false,
1255                                      $messagesearchstring, 'm'.$message->id, $strcontext);
1256                 echo html_writer::end_tag('div');
1257                 echo html_writer::end_tag('td');
1258
1259                 echo html_writer::tag('td', userdate($message->timecreated, $dateformat), array('class' => 'date'));
1260
1261                 echo html_writer::end_tag('tr');
1262             }
1263
1264
1265             if ($blockedcount > 0) {
1266                 echo html_writer::start_tag('tr');
1267                 echo html_writer::tag('td', get_string('blockedmessages', 'message', $blockedcount), array('colspan' => 4, 'align' => 'center'));
1268                 echo html_writer::end_tag('tr');
1269             }
1270             echo html_writer::end_tag('table');
1271
1272         } else {
1273             echo html_writer::tag('p', get_string('keywordssearchresults', 'message', 0), array('class' => 'heading'));
1274         }
1275     }
1276
1277     if (!$personsearch && !$messagesearch) {
1278         //they didn't enter any search terms
1279         echo $OUTPUT->notification(get_string('emptysearchstring', 'message'));
1280     }
1281
1282     echo html_writer::end_tag('div');
1283 }
1284
1285 /**
1286  * Print information on a user. Used when printing search results.
1287  *
1288  * @param object/bool $user the user to display or false if you just want $USER
1289  * @param bool $iscontact is the user being displayed a contact?
1290  * @param bool $isblocked is the user being displayed blocked?
1291  * @param bool $includeicontext include text next to the action icons?
1292  * @return void
1293  */
1294 function message_print_user ($user=false, $iscontact=false, $isblocked=false, $includeicontext=false) {
1295     global $USER, $OUTPUT;
1296
1297     if ($user === false) {
1298         echo $OUTPUT->user_picture($USER, array('size' => 20, 'courseid' => SITEID));
1299     } else {
1300         echo $OUTPUT->user_picture($user, array('size' => 20, 'courseid' => SITEID));
1301
1302         $link = new moodle_url("/message/index.php?id=$user->id");
1303         echo $OUTPUT->action_link($link, fullname($user), null, array('title' =>
1304                 get_string('sendmessageto', 'message', fullname($user))));
1305
1306         $return = false;
1307         $script = null;
1308         if ($iscontact) {
1309             message_contact_link($user->id, 'remove', $return, $script, $includeicontext);
1310         } else {
1311             message_contact_link($user->id, 'add', $return, $script, $includeicontext);
1312         }
1313
1314         if ($isblocked) {
1315             message_contact_link($user->id, 'unblock', $return, $script, $includeicontext);
1316         } else {
1317             message_contact_link($user->id, 'block', $return, $script, $includeicontext);
1318         }
1319     }
1320 }
1321
1322 /**
1323  * Print a message contact link
1324  *
1325  * @param int $userid the ID of the user to apply to action to
1326  * @param string $linktype can be add, remove, block or unblock
1327  * @param bool $return if true return the link as a string. If false echo the link.
1328  * @param string $script the URL to send the user to when the link is clicked. If null, the current page.
1329  * @param bool $text include text next to the icons?
1330  * @param bool $icon include a graphical icon?
1331  * @return string  if $return is true otherwise bool
1332  */
1333 function message_contact_link($userid, $linktype='add', $return=false, $script=null, $text=false, $icon=true) {
1334     global $OUTPUT, $PAGE;
1335
1336     //hold onto the strings as we're probably creating a bunch of links
1337     static $str;
1338
1339     if (empty($script)) {
1340         //strip off previous action params like 'removecontact'
1341         $script = message_remove_url_params($PAGE->url);
1342     }
1343
1344     if (empty($str->blockcontact)) {
1345        $str = new stdClass();
1346        $str->blockcontact   =  get_string('blockcontact', 'message');
1347        $str->unblockcontact =  get_string('unblockcontact', 'message');
1348        $str->removecontact  =  get_string('removecontact', 'message');
1349        $str->addcontact     =  get_string('addcontact', 'message');
1350     }
1351
1352     $command = $linktype.'contact';
1353     $string  = $str->{$command};
1354
1355     $safealttext = s($string);
1356
1357     $safestring = '';
1358     if (!empty($text)) {
1359         $safestring = $safealttext;
1360     }
1361
1362     $img = '';
1363     if ($icon) {
1364         $iconpath = null;
1365         switch ($linktype) {
1366             case 'block':
1367                 $iconpath = 't/block';
1368                 break;
1369             case 'unblock':
1370                 $iconpath = 't/unblock';
1371                 break;
1372             case 'remove':
1373                 $iconpath = 't/removecontact';
1374                 break;
1375             case 'add':
1376             default:
1377                 $iconpath = 't/addcontact';
1378         }
1379
1380         $img = '<img src="'.$OUTPUT->pix_url($iconpath).'" class="iconsmall" alt="'.$safealttext.'" />';
1381     }
1382
1383     $output = '<span class="'.$linktype.'contact">'.
1384               '<a href="'.$script.'&amp;'.$command.'='.$userid.
1385               '&amp;sesskey='.sesskey().'" title="'.$safealttext.'">'.
1386               $img.
1387               $safestring.'</a></span>';
1388
1389     if ($return) {
1390         return $output;
1391     } else {
1392         echo $output;
1393         return true;
1394     }
1395 }
1396
1397 /**
1398  * echo or return a link to take the user to the full message history between themselves and another user
1399  *
1400  * @param int $userid1 the ID of the user displayed on the left (usually the current user)
1401  * @param int $userid2 the ID of the other user
1402  * @param bool $return true to return the link as a string. False to echo the link.
1403  * @param string $keywords any keywords to highlight in the message history
1404  * @param string $position anchor name to jump to within the message history
1405  * @param string $linktext optionally specify the link text
1406  * @return string|bool. Returns a string if $return is true. Otherwise returns a boolean.
1407  */
1408 function message_history_link($userid1, $userid2, $return=false, $keywords='', $position='', $linktext='') {
1409     global $OUTPUT;
1410     static $strmessagehistory;
1411
1412     if (empty($strmessagehistory)) {
1413         $strmessagehistory = get_string('messagehistory', 'message');
1414     }
1415
1416     if ($position) {
1417         $position = "#$position";
1418     }
1419     if ($keywords) {
1420         $keywords = "&search=".urlencode($keywords);
1421     }
1422
1423     if ($linktext == 'icon') {  // Icon only
1424         $fulllink = '<img src="'.$OUTPUT->pix_url('t/messages') . '" class="iconsmall" alt="'.$strmessagehistory.'" />';
1425     } else if ($linktext == 'both') {  // Icon and standard name
1426         $fulllink = '<img src="'.$OUTPUT->pix_url('t/messages') . '" class="iconsmall" alt="" />';
1427         $fulllink .= '&nbsp;'.$strmessagehistory;
1428     } else if ($linktext) {    // Custom name
1429         $fulllink = $linktext;
1430     } else {                   // Standard name only
1431         $fulllink = $strmessagehistory;
1432     }
1433
1434     $popupoptions = array(
1435             'height' => 500,
1436             'width' => 500,
1437             'menubar' => false,
1438             'location' => false,
1439             'status' => true,
1440             'scrollbars' => true,
1441             'resizable' => true);
1442
1443     $link = new moodle_url('/message/index.php?history='.MESSAGE_HISTORY_ALL."&user1=$userid1&user2=$userid2$keywords$position");
1444     $action = null;
1445     $str = $OUTPUT->action_link($link, $fulllink, $action, array('title' => $strmessagehistory));
1446
1447     $str = '<span class="history">'.$str.'</span>';
1448
1449     if ($return) {
1450         return $str;
1451     } else {
1452         echo $str;
1453         return true;
1454     }
1455 }
1456
1457
1458 /**
1459  * Search through course users.
1460  *
1461  * If $courseids contains the site course then this function searches
1462  * through all undeleted and confirmed users.
1463  *
1464  * @param int|array $courseids Course ID or array of course IDs.
1465  * @param string $searchtext the text to search for.
1466  * @param string $sort the column name to order by.
1467  * @param string|array $exceptions comma separated list or array of user IDs to exclude.
1468  * @return array An array of {@link $USER} records.
1469  */
1470 function message_search_users($courseids, $searchtext, $sort='', $exceptions='') {
1471     global $CFG, $USER, $DB;
1472
1473     // Basic validation to ensure that the parameter $courseids is not an empty array or an empty value.
1474     if (!$courseids) {
1475         $courseids = array(SITEID);
1476     }
1477
1478     // Allow an integer to be passed.
1479     if (!is_array($courseids)) {
1480         $courseids = array($courseids);
1481     }
1482
1483     $fullname = $DB->sql_fullname();
1484     $ufields = user_picture::fields('u');
1485
1486     if (!empty($sort)) {
1487         $order = ' ORDER BY '. $sort;
1488     } else {
1489         $order = '';
1490     }
1491
1492     $params = array(
1493         'userid' => $USER->id,
1494         'query' => "%$searchtext%"
1495     );
1496
1497     if (empty($exceptions)) {
1498         $exceptions = array();
1499     } else if (!empty($exceptions) && is_string($exceptions)) {
1500         $exceptions = explode(',', $exceptions);
1501     }
1502
1503     // Ignore self and guest account.
1504     $exceptions[] = $USER->id;
1505     $exceptions[] = $CFG->siteguest;
1506
1507     // Exclude exceptions from the search result.
1508     list($except, $params_except) = $DB->get_in_or_equal($exceptions, SQL_PARAMS_NAMED, 'param', false);
1509     $except = ' AND u.id ' . $except;
1510     $params = array_merge($params_except, $params);
1511
1512     if (in_array(SITEID, $courseids)) {
1513         // Search on site level.
1514         return $DB->get_records_sql("SELECT $ufields, mc.id as contactlistid, mc.blocked
1515                                        FROM {user} u
1516                                        LEFT JOIN {message_contacts} mc
1517                                             ON mc.contactid = u.id AND mc.userid = :userid
1518                                       WHERE u.deleted = '0' AND u.confirmed = '1'
1519                                             AND (".$DB->sql_like($fullname, ':query', false).")
1520                                             $except
1521                                      $order", $params);
1522     } else {
1523         // Search in courses.
1524
1525         // Getting the context IDs or each course.
1526         $contextids = array();
1527         foreach ($courseids as $courseid) {
1528             $context = context_course::instance($courseid);
1529             $contextids = array_merge($contextids, $context->get_parent_context_ids(true));
1530         }
1531         list($contextwhere, $contextparams) = $DB->get_in_or_equal(array_unique($contextids), SQL_PARAMS_NAMED, 'context');
1532         $params = array_merge($params, $contextparams);
1533
1534         // Everyone who has a role assignment in this course or higher.
1535         // TODO: add enabled enrolment join here (skodak)
1536         $users = $DB->get_records_sql("SELECT DISTINCT $ufields, mc.id as contactlistid, mc.blocked
1537                                          FROM {user} u
1538                                          JOIN {role_assignments} ra ON ra.userid = u.id
1539                                          LEFT JOIN {message_contacts} mc
1540                                               ON mc.contactid = u.id AND mc.userid = :userid
1541                                         WHERE u.deleted = '0' AND u.confirmed = '1'
1542                                               AND (".$DB->sql_like($fullname, ':query', false).")
1543                                               AND ra.contextid $contextwhere
1544                                               $except
1545                                        $order", $params);
1546
1547         return $users;
1548     }
1549 }
1550
1551 /**
1552  * Search a user's messages
1553  *
1554  * Returns a list of posts found using an array of search terms
1555  * eg   word  +word -word
1556  *
1557  * @param array $searchterms an array of search terms (strings)
1558  * @param bool $fromme include messages from the user?
1559  * @param bool $tome include messages to the user?
1560  * @param mixed $courseid SITEID for admins searching all messages. Other behaviour not yet implemented
1561  * @param int $userid the user ID of the current user
1562  * @return mixed An array of messages or false if no matching messages were found
1563  */
1564 function message_search($searchterms, $fromme=true, $tome=true, $courseid='none', $userid=0) {
1565     global $CFG, $USER, $DB;
1566
1567     // If user is searching all messages check they are allowed to before doing anything else.
1568     if ($courseid == SITEID && !has_capability('moodle/site:readallmessages', context_system::instance())) {
1569         print_error('accessdenied','admin');
1570     }
1571
1572     // If no userid sent then assume current user.
1573     if ($userid == 0) $userid = $USER->id;
1574
1575     // Some differences in SQL syntax.
1576     if ($DB->sql_regex_supported()) {
1577         $REGEXP    = $DB->sql_regex(true);
1578         $NOTREGEXP = $DB->sql_regex(false);
1579     }
1580
1581     $searchcond = array();
1582     $params = array();
1583     $i = 0;
1584
1585     // Preprocess search terms to check whether we have at least 1 eligible search term.
1586     // If we do we can drop words around it like 'a'.
1587     $dropshortwords = false;
1588     foreach ($searchterms as $searchterm) {
1589         if (strlen($searchterm) >= 2) {
1590             $dropshortwords = true;
1591         }
1592     }
1593
1594     foreach ($searchterms as $searchterm) {
1595         $i++;
1596
1597         $NOT = false; // Initially we aren't going to perform NOT LIKE searches, only MSSQL and Oracle.
1598
1599         if ($dropshortwords && strlen($searchterm) < 2) {
1600             continue;
1601         }
1602         // Under Oracle and MSSQL, trim the + and - operators and perform simpler LIKE search.
1603         if (!$DB->sql_regex_supported()) {
1604             if (substr($searchterm, 0, 1) == '-') {
1605                 $NOT = true;
1606             }
1607             $searchterm = trim($searchterm, '+-');
1608         }
1609
1610         if (substr($searchterm,0,1) == "+") {
1611             $searchterm = substr($searchterm,1);
1612             $searchterm = preg_quote($searchterm, '|');
1613             $searchcond[] = "m.fullmessage $REGEXP :ss$i";
1614             $params['ss'.$i] = "(^|[^a-zA-Z0-9])$searchterm([^a-zA-Z0-9]|$)";
1615
1616         } else if (substr($searchterm,0,1) == "-") {
1617             $searchterm = substr($searchterm,1);
1618             $searchterm = preg_quote($searchterm, '|');
1619             $searchcond[] = "m.fullmessage $NOTREGEXP :ss$i";
1620             $params['ss'.$i] = "(^|[^a-zA-Z0-9])$searchterm([^a-zA-Z0-9]|$)";
1621
1622         } else {
1623             $searchcond[] = $DB->sql_like("m.fullmessage", ":ss$i", false, true, $NOT);
1624             $params['ss'.$i] = "%$searchterm%";
1625         }
1626     }
1627
1628     if (empty($searchcond)) {
1629         $searchcond = " ".$DB->sql_like('m.fullmessage', ':ss1', false);
1630         $params['ss1'] = "%";
1631     } else {
1632         $searchcond = implode(" AND ", $searchcond);
1633     }
1634
1635     // There are several possibilities
1636     // 1. courseid = SITEID : The admin is searching messages by all users
1637     // 2. courseid = ??     : A teacher is searching messages by users in
1638     //                        one of their courses - currently disabled
1639     // 3. courseid = none   : User is searching their own messages;
1640     //    a.  Messages from user
1641     //    b.  Messages to user
1642     //    c.  Messages to and from user
1643
1644     if ($courseid == SITEID) { // Admin is searching all messages.
1645         $m_read   = $DB->get_records_sql("SELECT m.id, m.useridto, m.useridfrom, m.smallmessage, m.fullmessage, m.timecreated
1646                                             FROM {message_read} m
1647                                            WHERE $searchcond", $params, 0, MESSAGE_SEARCH_MAX_RESULTS);
1648         $m_unread = $DB->get_records_sql("SELECT m.id, m.useridto, m.useridfrom, m.smallmessage, m.fullmessage, m.timecreated
1649                                             FROM {message} m
1650                                            WHERE $searchcond", $params, 0, MESSAGE_SEARCH_MAX_RESULTS);
1651
1652     } else if ($courseid !== 'none') {
1653         // This has not been implemented due to security concerns.
1654         $m_read   = array();
1655         $m_unread = array();
1656
1657     } else {
1658
1659         if ($fromme and $tome) {
1660             $searchcond .= " AND (m.useridfrom=:userid1 OR m.useridto=:userid2)";
1661             $params['userid1'] = $userid;
1662             $params['userid2'] = $userid;
1663
1664         } else if ($fromme) {
1665             $searchcond .= " AND m.useridfrom=:userid";
1666             $params['userid'] = $userid;
1667
1668         } else if ($tome) {
1669             $searchcond .= " AND m.useridto=:userid";
1670             $params['userid'] = $userid;
1671         }
1672
1673         $m_read   = $DB->get_records_sql("SELECT m.id, m.useridto, m.useridfrom, m.smallmessage, m.fullmessage, m.timecreated
1674                                             FROM {message_read} m
1675                                            WHERE $searchcond", $params, 0, MESSAGE_SEARCH_MAX_RESULTS);
1676         $m_unread = $DB->get_records_sql("SELECT m.id, m.useridto, m.useridfrom, m.smallmessage, m.fullmessage, m.timecreated
1677                                             FROM {message} m
1678                                            WHERE $searchcond", $params, 0, MESSAGE_SEARCH_MAX_RESULTS);
1679
1680     }
1681
1682     /// The keys may be duplicated in $m_read and $m_unread so we can't
1683     /// do a simple concatenation
1684     $messages = array();
1685     foreach ($m_read as $m) {
1686         $messages[] = $m;
1687     }
1688     foreach ($m_unread as $m) {
1689         $messages[] = $m;
1690     }
1691
1692     return (empty($messages)) ? false : $messages;
1693 }
1694
1695 /**
1696  * Given a message object that we already know has a long message
1697  * this function truncates the message nicely to the first
1698  * sane place between $CFG->forum_longpost and $CFG->forum_shortpost
1699  *
1700  * @param string $message the message
1701  * @param int $minlength the minimum length to trim the message to
1702  * @return string the shortened message
1703  */
1704 function message_shorten_message($message, $minlength = 0) {
1705     $i = 0;
1706     $tag = false;
1707     $length = strlen($message);
1708     $count = 0;
1709     $stopzone = false;
1710     $truncate = 0;
1711     if ($minlength == 0) $minlength = MESSAGE_SHORTLENGTH;
1712
1713
1714     for ($i=0; $i<$length; $i++) {
1715         $char = $message[$i];
1716
1717         switch ($char) {
1718             case "<":
1719                 $tag = true;
1720                 break;
1721             case ">":
1722                 $tag = false;
1723                 break;
1724             default:
1725                 if (!$tag) {
1726                     if ($stopzone) {
1727                         if ($char == '.' or $char == ' ') {
1728                             $truncate = $i+1;
1729                             break 2;
1730                         }
1731                     }
1732                     $count++;
1733                 }
1734                 break;
1735         }
1736         if (!$stopzone) {
1737             if ($count > $minlength) {
1738                 $stopzone = true;
1739             }
1740         }
1741     }
1742
1743     if (!$truncate) {
1744         $truncate = $i;
1745     }
1746
1747     return substr($message, 0, $truncate);
1748 }
1749
1750
1751 /**
1752  * Given a string and an array of keywords, this function looks
1753  * for the first keyword in the string, and then chops out a
1754  * small section from the text that shows that word in context.
1755  *
1756  * @param string $message the text to search
1757  * @param array $keywords array of keywords to find
1758  */
1759 function message_get_fragment($message, $keywords) {
1760
1761     $fullsize = 160;
1762     $halfsize = (int)($fullsize/2);
1763
1764     $message = strip_tags($message);
1765
1766     foreach ($keywords as $keyword) {  // Just get the first one
1767         if ($keyword !== '') {
1768             break;
1769         }
1770     }
1771     if (empty($keyword)) {   // None found, so just return start of message
1772         return message_shorten_message($message, 30);
1773     }
1774
1775     $leadin = $leadout = '';
1776
1777 /// Find the start of the fragment
1778     $start = 0;
1779     $length = strlen($message);
1780
1781     $pos = strpos($message, $keyword);
1782     if ($pos > $halfsize) {
1783         $start = $pos - $halfsize;
1784         $leadin = '...';
1785     }
1786 /// Find the end of the fragment
1787     $end = $start + $fullsize;
1788     if ($end > $length) {
1789         $end = $length;
1790     } else {
1791         $leadout = '...';
1792     }
1793
1794 /// Pull out the fragment and format it
1795
1796     $fragment = substr($message, $start, $end - $start);
1797     $fragment = $leadin.highlight(implode(' ',$keywords), $fragment).$leadout;
1798     return $fragment;
1799 }
1800
1801 /**
1802  * Retrieve the messages between two users
1803  *
1804  * @param object $user1 the current user
1805  * @param object $user2 the other user
1806  * @param int $limitnum the maximum number of messages to retrieve
1807  * @param bool $viewingnewmessages are we currently viewing new messages?
1808  */
1809 function message_get_history($user1, $user2, $limitnum=0, $viewingnewmessages=false) {
1810     global $DB, $CFG;
1811
1812     $messages = array();
1813
1814     //we want messages sorted oldest to newest but if getting a subset of messages we need to sort
1815     //desc to get the last $limitnum messages then flip the order in php
1816     $sort = 'asc';
1817     if ($limitnum>0) {
1818         $sort = 'desc';
1819     }
1820
1821     $notificationswhere = null;
1822     //we have just moved new messages to read. If theyre here to see new messages dont hide notifications
1823     if (!$viewingnewmessages && $CFG->messaginghidereadnotifications) {
1824         $notificationswhere = 'AND notification=0';
1825     }
1826
1827     //prevent notifications of your own actions appearing in your own message history
1828     $ownnotificationwhere = ' AND NOT (useridfrom=? AND notification=1)';
1829
1830     if ($messages_read = $DB->get_records_select('message_read', "((useridto = ? AND useridfrom = ?) OR
1831                                                     (useridto = ? AND useridfrom = ?)) $notificationswhere $ownnotificationwhere",
1832                                                     array($user1->id, $user2->id, $user2->id, $user1->id, $user1->id),
1833                                                     "timecreated $sort", '*', 0, $limitnum)) {
1834         foreach ($messages_read as $message) {
1835             $messages[] = $message;
1836         }
1837     }
1838     if ($messages_new =  $DB->get_records_select('message', "((useridto = ? AND useridfrom = ?) OR
1839                                                     (useridto = ? AND useridfrom = ?)) $ownnotificationwhere",
1840                                                     array($user1->id, $user2->id, $user2->id, $user1->id, $user1->id),
1841                                                     "timecreated $sort", '*', 0, $limitnum)) {
1842         foreach ($messages_new as $message) {
1843             $messages[] = $message;
1844         }
1845     }
1846
1847     $result = collatorlib::asort_objects_by_property($messages, 'timecreated', collatorlib::SORT_NUMERIC);
1848
1849     //if we only want the last $limitnum messages
1850     $messagecount = count($messages);
1851     if ($limitnum > 0 && $messagecount > $limitnum) {
1852         $messages = array_slice($messages, $messagecount - $limitnum, $limitnum, true);
1853     }
1854
1855     return $messages;
1856 }
1857
1858 /**
1859  * Print the message history between two users
1860  *
1861  * @param object $user1 the current user
1862  * @param object $user2 the other user
1863  * @param string $search search terms to highlight
1864  * @param int $messagelimit maximum number of messages to return
1865  * @param string $messagehistorylink the html for the message history link or false
1866  * @param bool $viewingnewmessages are we currently viewing new messages?
1867  */
1868 function message_print_message_history($user1, $user2 ,$search = '', $messagelimit = 0, $messagehistorylink = false, $viewingnewmessages = false, $showactionlinks = true) {
1869     global $CFG, $OUTPUT;
1870
1871     echo $OUTPUT->box_start('center');
1872     echo html_writer::start_tag('table', array('cellpadding' => '10', 'class' => 'message_user_pictures'));
1873     echo html_writer::start_tag('tr');
1874
1875     echo html_writer::start_tag('td', array('align' => 'center', 'id' => 'user1'));
1876     echo $OUTPUT->user_picture($user1, array('size' => 100, 'courseid' => SITEID));
1877     echo html_writer::tag('div', fullname($user1), array('class' => 'heading'));
1878     echo html_writer::end_tag('td');
1879
1880     echo html_writer::start_tag('td', array('align' => 'center'));
1881     echo html_writer::empty_tag('img', array('src' => $OUTPUT->pix_url('i/twoway'), 'alt' => ''));
1882     echo html_writer::end_tag('td');
1883
1884     echo html_writer::start_tag('td', array('align' => 'center', 'id' => 'user2'));
1885     echo $OUTPUT->user_picture($user2, array('size' => 100, 'courseid' => SITEID));
1886     echo html_writer::tag('div', fullname($user2), array('class' => 'heading'));
1887
1888     if ($showactionlinks && isset($user2->iscontact) && isset($user2->isblocked)) {
1889
1890         $script = null;
1891         $text = true;
1892         $icon = false;
1893
1894         $strcontact = message_get_contact_add_remove_link($user2->iscontact, $user2->isblocked, $user2, $script, $text, $icon);
1895         $strblock   = message_get_contact_block_link($user2->iscontact, $user2->isblocked, $user2, $script, $text, $icon);
1896         $useractionlinks = $strcontact.'&nbsp;|'.$strblock;
1897
1898         echo html_writer::tag('div', $useractionlinks, array('class' => 'useractionlinks'));
1899     }
1900
1901     echo html_writer::end_tag('td');
1902     echo html_writer::end_tag('tr');
1903     echo html_writer::end_tag('table');
1904     echo $OUTPUT->box_end();
1905
1906     if (!empty($messagehistorylink)) {
1907         echo $messagehistorylink;
1908     }
1909
1910     /// Get all the messages and print them
1911     if ($messages = message_get_history($user1, $user2, $messagelimit, $viewingnewmessages)) {
1912         $tablecontents = '';
1913
1914         $current = new stdClass();
1915         $current->mday = '';
1916         $current->month = '';
1917         $current->year = '';
1918         $messagedate = get_string('strftimetime');
1919         $blockdate   = get_string('strftimedaydate');
1920         foreach ($messages as $message) {
1921             if ($message->notification) {
1922                 $notificationclass = ' notification';
1923             } else {
1924                 $notificationclass = null;
1925             }
1926             $date = usergetdate($message->timecreated);
1927             if ($current->mday != $date['mday'] | $current->month != $date['month'] | $current->year != $date['year']) {
1928                 $current->mday = $date['mday'];
1929                 $current->month = $date['month'];
1930                 $current->year = $date['year'];
1931
1932                 $datestring = html_writer::empty_tag('a', array('name' => $date['year'].$date['mon'].$date['mday']));
1933                 $tablecontents .= html_writer::tag('div', $datestring, array('class' => 'mdl-align heading'));
1934
1935                 $tablecontents .= $OUTPUT->heading(userdate($message->timecreated, $blockdate), 4, 'mdl-align');
1936             }
1937
1938             $formatted_message = $side = null;
1939             if ($message->useridfrom == $user1->id) {
1940                 $formatted_message = message_format_message($message, $messagedate, $search, 'me');
1941                 $side = 'left';
1942             } else {
1943                 $formatted_message = message_format_message($message, $messagedate, $search, 'other');
1944                 $side = 'right';
1945             }
1946             $tablecontents .= html_writer::tag('div', $formatted_message, array('class' => "mdl-left $side $notificationclass"));
1947         }
1948
1949         echo html_writer::nonempty_tag('div', $tablecontents, array('class' => 'mdl-left messagehistory'));
1950     } else {
1951         echo html_writer::nonempty_tag('div', '('.get_string('nomessagesfound', 'message').')', array('class' => 'mdl-align messagehistory'));
1952     }
1953 }
1954
1955 /**
1956  * Format a message for display in the message history
1957  *
1958  * @param object $message the message object
1959  * @param string $format optional date format
1960  * @param string $keywords keywords to highlight
1961  * @param string $class CSS class to apply to the div around the message
1962  * @return string the formatted message
1963  */
1964 function message_format_message($message, $format='', $keywords='', $class='other') {
1965
1966     static $dateformat;
1967
1968     //if we haven't previously set the date format or they've supplied a new one
1969     if ( empty($dateformat) || (!empty($format) && $dateformat != $format) ) {
1970         if ($format) {
1971             $dateformat = $format;
1972         } else {
1973             $dateformat = get_string('strftimedatetimeshort');
1974         }
1975     }
1976     $time = userdate($message->timecreated, $dateformat);
1977     $options = new stdClass();
1978     $options->para = false;
1979
1980     //if supplied display small messages as fullmessage may contain boilerplate text that shouldnt appear in the messaging UI
1981     if (!empty($message->smallmessage)) {
1982         $messagetext = $message->smallmessage;
1983     } else {
1984         $messagetext = $message->fullmessage;
1985     }
1986     if ($message->fullmessageformat == FORMAT_HTML) {
1987         //dont escape html tags by calling s() if html format or they will display in the UI
1988         $messagetext = html_to_text(format_text($messagetext, $message->fullmessageformat, $options));
1989     } else {
1990         $messagetext = format_text(s($messagetext), $message->fullmessageformat, $options);
1991     }
1992
1993     $messagetext .= message_format_contexturl($message);
1994
1995     if ($keywords) {
1996         $messagetext = highlight($keywords, $messagetext);
1997     }
1998
1999     return <<<TEMPLATE
2000 <div class='message $class'>
2001     <a name="m'.{$message->id}.'"></a>
2002     <span class="message-meta"><span class="time">$time</span></span>: <span class="text">$messagetext</span>
2003 </div>
2004 TEMPLATE;
2005 }
2006
2007 /**
2008  * Format a the context url and context url name of a message for display
2009  *
2010  * @param object $message the message object
2011  * @return string the formatted string
2012  */
2013 function message_format_contexturl($message) {
2014     $s = null;
2015
2016     if (!empty($message->contexturl)) {
2017         $displaytext = null;
2018         if (!empty($message->contexturlname)) {
2019             $displaytext= $message->contexturlname;
2020         } else {
2021             $displaytext= $message->contexturl;
2022         }
2023         $s .= html_writer::start_tag('div',array('class' => 'messagecontext'));
2024             $s .= get_string('view').': '.html_writer::tag('a', $displaytext, array('href' => $message->contexturl));
2025         $s .= html_writer::end_tag('div');
2026     }
2027
2028     return $s;
2029 }
2030
2031 /**
2032  * Send a message from one user to another. Will be delivered according to the message recipients messaging preferences
2033  *
2034  * @param object $userfrom the message sender
2035  * @param object $userto the message recipient
2036  * @param string $message the message
2037  * @param int $format message format such as FORMAT_PLAIN or FORMAT_HTML
2038  * @return int|false the ID of the new message or false
2039  */
2040 function message_post_message($userfrom, $userto, $message, $format) {
2041     global $SITE, $CFG, $USER;
2042
2043     $eventdata = new stdClass();
2044     $eventdata->component        = 'moodle';
2045     $eventdata->name             = 'instantmessage';
2046     $eventdata->userfrom         = $userfrom;
2047     $eventdata->userto           = $userto;
2048
2049     //using string manager directly so that strings in the message will be in the message recipients language rather than the senders
2050     $eventdata->subject          = get_string_manager()->get_string('unreadnewmessage', 'message', fullname($userfrom), $userto->lang);
2051
2052     if ($format == FORMAT_HTML) {
2053         $eventdata->fullmessagehtml  = $message;
2054         //some message processors may revert to sending plain text even if html is supplied
2055         //so we keep both plain and html versions if we're intending to send html
2056         $eventdata->fullmessage = html_to_text($eventdata->fullmessagehtml);
2057     } else {
2058         $eventdata->fullmessage      = $message;
2059         $eventdata->fullmessagehtml  = '';
2060     }
2061
2062     $eventdata->fullmessageformat = $format;
2063     $eventdata->smallmessage     = $message;//store the message unfiltered. Clean up on output.
2064
2065     $s = new stdClass();
2066     $s->sitename = format_string($SITE->shortname, true, array('context' => context_course::instance(SITEID)));
2067     $s->url = $CFG->wwwroot.'/message/index.php?user='.$userto->id.'&id='.$userfrom->id;
2068
2069     $emailtagline = get_string_manager()->get_string('emailtagline', 'message', $s, $userto->lang);
2070     if (!empty($eventdata->fullmessage)) {
2071         $eventdata->fullmessage .= "\n\n---------------------------------------------------------------------\n".$emailtagline;
2072     }
2073     if (!empty($eventdata->fullmessagehtml)) {
2074         $eventdata->fullmessagehtml .= "<br /><br />---------------------------------------------------------------------<br />".$emailtagline;
2075     }
2076
2077     $eventdata->timecreated     = time();
2078     return message_send($eventdata);
2079 }
2080
2081 /**
2082  * Print a row of contactlist displaying user picture, messages waiting and
2083  * block links etc
2084  *
2085  * @param object $contact contact object containing all fields required for $OUTPUT->user_picture()
2086  * @param bool $incontactlist is the user a contact of ours?
2087  * @param bool $isblocked is the user blocked?
2088  * @param string $selectcontacturl the url to send the user to when a contact's name is clicked
2089  * @param bool $showactionlinks display action links next to the other users (add contact, block user etc)
2090  * @param object $selecteduser the user the current user is viewing (if any). They will be highlighted.
2091  * @return void
2092  */
2093 function message_print_contactlist_user($contact, $incontactlist = true, $isblocked = false, $selectcontacturl = null, $showactionlinks = true, $selecteduser=null) {
2094     global $OUTPUT, $USER;
2095     $fullname  = fullname($contact);
2096     $fullnamelink  = $fullname;
2097
2098     $linkclass = '';
2099     if (!empty($selecteduser) && $contact->id == $selecteduser->id) {
2100         $linkclass = 'messageselecteduser';
2101     }
2102
2103     // Are there any unread messages for this contact?
2104     if ($contact->messagecount > 0 ){
2105         $fullnamelink = '<strong>'.$fullnamelink.' ('.$contact->messagecount.')</strong>';
2106     }
2107
2108     $strcontact = $strblock = $strhistory = null;
2109
2110     if ($showactionlinks) {
2111         $strcontact = message_get_contact_add_remove_link($incontactlist, $isblocked, $contact);
2112         $strblock   = message_get_contact_block_link($incontactlist, $isblocked, $contact);
2113         $strhistory = message_history_link($USER->id, $contact->id, true, '', '', 'icon');
2114     }
2115
2116     echo html_writer::start_tag('tr');
2117     echo html_writer::start_tag('td', array('class' => 'pix'));
2118     echo $OUTPUT->user_picture($contact, array('size' => 20, 'courseid' => SITEID));
2119     echo html_writer::end_tag('td');
2120
2121     echo html_writer::start_tag('td', array('class' => 'contact'));
2122
2123     $popupoptions = array(
2124             'height' => MESSAGE_DISCUSSION_HEIGHT,
2125             'width' => MESSAGE_DISCUSSION_WIDTH,
2126             'menubar' => false,
2127             'location' => false,
2128             'status' => true,
2129             'scrollbars' => true,
2130             'resizable' => true);
2131
2132     $link = $action = null;
2133     if (!empty($selectcontacturl)) {
2134         $link = new moodle_url($selectcontacturl.'&user2='.$contact->id);
2135     } else {
2136         //can $selectcontacturl be removed and maybe the be removed and hardcoded?
2137         $link = new moodle_url("/message/index.php?id=$contact->id");
2138         $action = new popup_action('click', $link, "message_$contact->id", $popupoptions);
2139     }
2140     echo $OUTPUT->action_link($link, $fullnamelink, $action, array('class' => $linkclass,'title' => get_string('sendmessageto', 'message', $fullname)));
2141
2142     echo html_writer::end_tag('td');
2143
2144     echo html_writer::tag('td', '&nbsp;'.$strcontact.$strblock.'&nbsp;'.$strhistory, array('class' => 'link'));
2145
2146     echo html_writer::end_tag('tr');
2147 }
2148
2149 /**
2150  * Constructs the add/remove contact link to display next to other users
2151  *
2152  * @param bool $incontactlist is the user a contact
2153  * @param bool $isblocked is the user blocked
2154  * @param stdClass $contact contact object
2155  * @param string $script the URL to send the user to when the link is clicked. If null, the current page.
2156  * @param bool $text include text next to the icons?
2157  * @param bool $icon include a graphical icon?
2158  * @return string
2159  */
2160 function message_get_contact_add_remove_link($incontactlist, $isblocked, $contact, $script=null, $text=false, $icon=true) {
2161     $strcontact = '';
2162
2163     if($incontactlist){
2164         $strcontact = message_contact_link($contact->id, 'remove', true, $script, $text, $icon);
2165     } else if ($isblocked) {
2166         $strcontact = message_contact_link($contact->id, 'add', true, $script, $text, $icon);
2167     } else{
2168         $strcontact = message_contact_link($contact->id, 'add', true, $script, $text, $icon);
2169     }
2170
2171     return $strcontact;
2172 }
2173
2174 /**
2175  * Constructs the block contact link to display next to other users
2176  *
2177  * @param bool $incontactlist is the user a contact?
2178  * @param bool $isblocked is the user blocked?
2179  * @param stdClass $contact contact object
2180  * @param string $script the URL to send the user to when the link is clicked. If null, the current page.
2181  * @param bool $text include text next to the icons?
2182  * @param bool $icon include a graphical icon?
2183  * @return string
2184  */
2185 function message_get_contact_block_link($incontactlist, $isblocked, $contact, $script=null, $text=false, $icon=true) {
2186     $strblock   = '';
2187
2188     //commented out to allow the user to block a contact without having to remove them first
2189     /*if ($incontactlist) {
2190         //$strblock = '';
2191     } else*/
2192     if ($isblocked) {
2193         $strblock   = '&nbsp;'.message_contact_link($contact->id, 'unblock', true, $script, $text, $icon);
2194     } else{
2195         $strblock   = '&nbsp;'.message_contact_link($contact->id, 'block', true, $script, $text, $icon);
2196     }
2197
2198     return $strblock;
2199 }
2200
2201 /**
2202  * Moves messages from a particular user from the message table (unread messages) to message_read
2203  * This is typically only used when a user is deleted
2204  *
2205  * @param object $userid User id
2206  * @return boolean success
2207  */
2208 function message_move_userfrom_unread2read($userid) {
2209     global $DB;
2210
2211     // move all unread messages from message table to message_read
2212     if ($messages = $DB->get_records_select('message', 'useridfrom = ?', array($userid), 'timecreated')) {
2213         foreach ($messages as $message) {
2214             message_mark_message_read($message, 0); //set timeread to 0 as the message was never read
2215         }
2216     }
2217     return true;
2218 }
2219
2220 /**
2221  * marks ALL messages being sent from $fromuserid to $touserid as read
2222  *
2223  * @param int $touserid the id of the message recipient
2224  * @param int $fromuserid the id of the message sender
2225  * @return void
2226  */
2227 function message_mark_messages_read($touserid, $fromuserid){
2228     global $DB;
2229
2230     $sql = 'SELECT m.* FROM {message} m WHERE m.useridto=:useridto AND m.useridfrom=:useridfrom';
2231     $messages = $DB->get_recordset_sql($sql, array('useridto' => $touserid,'useridfrom' => $fromuserid));
2232
2233     foreach ($messages as $message) {
2234         message_mark_message_read($message, time());
2235     }
2236
2237     $messages->close();
2238 }
2239
2240 /**
2241  * Mark a single message as read
2242  *
2243  * @param stdClass $message An object with an object property ie $message->id which is an id in the message table
2244  * @param int $timeread the timestamp for when the message should be marked read. Usually time().
2245  * @param bool $messageworkingempty Is the message_working table already confirmed empty for this message?
2246  * @return int the ID of the message in the message_read table
2247  */
2248 function message_mark_message_read($message, $timeread, $messageworkingempty=false) {
2249     global $DB;
2250
2251     $message->timeread = $timeread;
2252
2253     $messageid = $message->id;
2254     unset($message->id);//unset because it will get a new id on insert into message_read
2255
2256     //If any processors have pending actions abort them
2257     if (!$messageworkingempty) {
2258         $DB->delete_records('message_working', array('unreadmessageid' => $messageid));
2259     }
2260     $messagereadid = $DB->insert_record('message_read', $message);
2261     $DB->delete_records('message', array('id' => $messageid));
2262     return $messagereadid;
2263 }
2264
2265 /**
2266  * A helper function that prints a formatted heading
2267  *
2268  * @param string $title the heading to display
2269  * @param int $colspan
2270  * @return void
2271  */
2272 function message_print_heading($title, $colspan=3) {
2273     echo html_writer::start_tag('tr');
2274     echo html_writer::tag('td', $title, array('colspan' => $colspan, 'class' => 'heading'));
2275     echo html_writer::end_tag('tr');
2276 }
2277
2278 /**
2279  * Get all message processors, validate corresponding plugin existance and
2280  * system configuration
2281  *
2282  * @param bool $ready only return ready-to-use processors
2283  * @return mixed $processors array of objects containing information on message processors
2284  */
2285 function get_message_processors($ready = false) {
2286     global $DB, $CFG;
2287
2288     static $processors;
2289
2290     if (empty($processors)) {
2291         // Get all processors, ensure the name column is the first so it will be the array key
2292         $processors = $DB->get_records('message_processors', null, 'name DESC', 'name, id, enabled');
2293         foreach ($processors as &$processor){
2294             $processorfile = $CFG->dirroot. '/message/output/'.$processor->name.'/message_output_'.$processor->name.'.php';
2295             if (is_readable($processorfile)) {
2296                 include_once($processorfile);
2297                 $processclass = 'message_output_' . $processor->name;
2298                 if (class_exists($processclass)) {
2299                     $pclass = new $processclass();
2300                     $processor->object = $pclass;
2301                     $processor->configured = 0;
2302                     if ($pclass->is_system_configured()) {
2303                         $processor->configured = 1;
2304                     }
2305                     $processor->hassettings = 0;
2306                     if (is_readable($CFG->dirroot.'/message/output/'.$processor->name.'/settings.php')) {
2307                         $processor->hassettings = 1;
2308                     }
2309                     $processor->available = 1;
2310                 } else {
2311                     print_error('errorcallingprocessor', 'message');
2312                 }
2313             } else {
2314                 $processor->available = 0;
2315             }
2316         }
2317     }
2318     if ($ready) {
2319         // Filter out enabled and system_configured processors
2320         $readyprocessors = $processors;
2321         foreach ($readyprocessors as $readyprocessor) {
2322             if (!($readyprocessor->enabled && $readyprocessor->configured)) {
2323                 unset($readyprocessors[$readyprocessor->name]);
2324             }
2325         }
2326         return $readyprocessors;
2327     }
2328
2329     return $processors;
2330 }
2331
2332 /**
2333  * Get all message providers, validate their plugin existance and
2334  * system configuration
2335  *
2336  * @return mixed $processors array of objects containing information on message processors
2337  */
2338 function get_message_providers() {
2339     global $CFG, $DB;
2340     require_once($CFG->libdir . '/pluginlib.php');
2341     $pluginman = plugin_manager::instance();
2342
2343     $providers = $DB->get_records('message_providers', null, 'name');
2344
2345     // Remove all the providers whose plugins are disabled or don't exist
2346     foreach ($providers as $providerid => $provider) {
2347         $plugin = $pluginman->get_plugin_info($provider->component);
2348         if ($plugin) {
2349             if ($plugin->get_status() === plugin_manager::PLUGIN_STATUS_MISSING) {
2350                 unset($providers[$providerid]);   // Plugins does not exist
2351                 continue;
2352             }
2353             if ($plugin->is_enabled() === false) {
2354                 unset($providers[$providerid]);   // Plugin disabled
2355                 continue;
2356             }
2357         }
2358     }
2359     return $providers;
2360 }
2361
2362 /**
2363  * Get an instance of the message_output class for one of the output plugins.
2364  * @param string $type the message output type. E.g. 'email' or 'jabber'.
2365  * @return message_output message_output the requested class.
2366  */
2367 function get_message_processor($type) {
2368     global $CFG;
2369
2370     // Note, we cannot use the get_message_processors function here, becaues this
2371     // code is called during install after installing each messaging plugin, and
2372     // get_message_processors caches the list of installed plugins.
2373
2374     $processorfile = $CFG->dirroot . "/message/output/{$type}/message_output_{$type}.php";
2375     if (!is_readable($processorfile)) {
2376         throw new coding_exception('Unknown message processor type ' . $type);
2377     }
2378
2379     include_once($processorfile);
2380
2381     $processclass = 'message_output_' . $type;
2382     if (!class_exists($processclass)) {
2383         throw new coding_exception('Message processor ' . $type .
2384                 ' does not define the right class');
2385     }
2386
2387     return new $processclass();
2388 }
2389
2390 /**
2391  * Get messaging outputs default (site) preferences
2392  *
2393  * @return object $processors object containing information on message processors
2394  */
2395 function get_message_output_default_preferences() {
2396     return get_config('message');
2397 }
2398
2399 /**
2400  * Translate message default settings from binary value to the array of string
2401  * representing the settings to be stored. Also validate the provided value and
2402  * use default if it is malformed.
2403  *
2404  * @param  int    $plugindefault Default setting suggested by plugin
2405  * @param  string $processorname The name of processor
2406  * @return array  $settings array of strings in the order: $permitted, $loggedin, $loggedoff.
2407  */
2408 function translate_message_default_setting($plugindefault, $processorname) {
2409     // Preset translation arrays
2410     $permittedvalues = array(
2411         0x04 => 'disallowed',
2412         0x08 => 'permitted',
2413         0x0c => 'forced',
2414     );
2415
2416     $loggedinstatusvalues = array(
2417         0x00 => null, // use null if loggedin/loggedoff is not defined
2418         0x01 => 'loggedin',
2419         0x02 => 'loggedoff',
2420     );
2421
2422     // define the default setting
2423     $processor = get_message_processor($processorname);
2424     $default = $processor->get_default_messaging_settings();
2425
2426     // Validate the value. It should not exceed the maximum size
2427     if (!is_int($plugindefault) || ($plugindefault > 0x0f)) {
2428         debugging(get_string('errortranslatingdefault', 'message'));
2429         $plugindefault = $default;
2430     }
2431     // Use plugin default setting of 'permitted' is 0
2432     if (!($plugindefault & MESSAGE_PERMITTED_MASK)) {
2433         $plugindefault = $default;
2434     }
2435
2436     $permitted = $permittedvalues[$plugindefault & MESSAGE_PERMITTED_MASK];
2437     $loggedin = $loggedoff = null;
2438
2439     if (($plugindefault & MESSAGE_PERMITTED_MASK) == MESSAGE_PERMITTED) {
2440         $loggedin = $loggedinstatusvalues[$plugindefault & MESSAGE_DEFAULT_LOGGEDIN];
2441         $loggedoff = $loggedinstatusvalues[$plugindefault & MESSAGE_DEFAULT_LOGGEDOFF];
2442     }
2443
2444     return array($permitted, $loggedin, $loggedoff);
2445 }
2446
2447 /**
2448  * Return a list of page types
2449  * @param string $pagetype current page type
2450  * @param stdClass $parentcontext Block's parent context
2451  * @param stdClass $currentcontext Current context of block
2452  */
2453 function message_page_type_list($pagetype, $parentcontext, $currentcontext) {
2454     return array('messages-*'=>get_string('page-message-x', 'message'));
2455 }
2456
2457 /**
2458  * Is $USER one of the supplied users?
2459  *
2460  * $user2 will be null if viewing a user's recent conversations
2461  *
2462  * @param stdClass the first user
2463  * @param stdClass the second user or null
2464  * @return bool True if the current user is one of either $user1 or $user2
2465  */
2466 function message_current_user_is_involved($user1, $user2) {
2467     global $USER;
2468
2469     if (empty($user1->id) || (!empty($user2) && empty($user2->id))) {
2470         throw new coding_exception('Invalid user object detected. Missing id.');
2471     }
2472
2473     if ($user1->id != $USER->id && (empty($user2) || $user2->id != $USER->id)) {
2474         return false;
2475     }
2476     return true;
2477 }