lib/messagelib.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  * Functions for interacting with the message system
  19  *
  20  * @package   core_message
  21  * @copyright 2008 Luis Rodrigues and Martin Dougiamas
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 defined('MOODLE_INTERNAL') || die();
  26
  27 require_once(__DIR__ . '/../message/lib.php');
  28
  29 /**
  30  * Called when a message provider wants to send a message.
  31  * This functions checks the message recipient's message processor configuration then
  32  * sends the message to the configured processors
  33  *
  34  * Required parameters of the $eventdata object:
  35  *  component string component name. must exist in message_providers
  36  *  name string message type name. must exist in message_providers
  37  *  userfrom object|int the user sending the message
  38  *  userto object|int the message recipient
  39  *  subject string the message subject
  40  *  fullmessage string the full message in a given format
  41  *  fullmessageformat int the format if the full message (FORMAT_MOODLE, FORMAT_HTML, ..)
  42  *  fullmessagehtml string the full version (the message processor will choose with one to use)
  43  *  smallmessage string the small version of the message
  44  *
  45  * Optional parameters of the $eventdata object:
  46  *  notification bool should the message be considered as a notification rather than a personal message
  47  *  contexturl string if this is a notification then you can specify a url to view the event. For example the forum post the user is being notified of.
  48  *  contexturlname string the display text for contexturl
  49  *
  50  * Note: processor failure is is not reported as false return value,
  51  *       earlier versions did not do it consistently either.
  52  *
  53  * @todo MDL-55449 Drop support for stdClass in Moodle 3.6
  54  * @category message
  55  * @param \core\message\message $eventdata information about the message (component, userfrom, userto, ...)
  56  * @return mixed the integer ID of the new message or false if there was a problem with submitted data
  57  */
  58 function message_send($eventdata) {
  59     global $CFG, $DB;
  60
  61     // TODO MDL-55449 Drop support for stdClass in Moodle 3.6.
  62     if ($eventdata instanceof \stdClass) {
  63         if (!isset($eventdata->courseid)) {
  64             $eventdata->courseid = null;
  65         }
  66
  67         debugging('eventdata as \stdClass is deprecated. Please use core\message\message instead.', DEBUG_DEVELOPER);
  68     }
  69
  70     //new message ID to return
  71     $messageid = false;
  72
  73     // Fetch default (site) preferences
  74     $defaultpreferences = get_message_output_default_preferences();
  75     $preferencebase = $eventdata->component.'_'.$eventdata->name;
  76     // If message provider is disabled then don't do any processing.
  77     if (!empty($defaultpreferences->{$preferencebase.'_disable'})) {
  78         return $messageid;
  79     }
  80
  81     // By default a message is a notification. Only personal/private messages aren't notifications.
  82     if (!isset($eventdata->notification)) {
  83         $eventdata->notification = 1;
  84     }
  85
  86     if (!is_object($eventdata->userto)) {
  87         $eventdata->userto = core_user::get_user($eventdata->userto);
  88     }
  89     if (!is_object($eventdata->userfrom)) {
  90         $eventdata->userfrom = core_user::get_user($eventdata->userfrom);
  91     }
  92     if (!$eventdata->userto) {
  93         debugging('Attempt to send msg to unknown user', DEBUG_NORMAL);
  94         return false;
  95     }
  96     if (!$eventdata->userfrom) {
  97         debugging('Attempt to send msg from unknown user', DEBUG_NORMAL);
  98         return false;
  99     }
 100
 101     // Verify all necessary data fields are present.
 102     if (!isset($eventdata->userto->auth) or !isset($eventdata->userto->suspended)
 103             or !isset($eventdata->userto->deleted) or !isset($eventdata->userto->emailstop)) {
 104
 105         debugging('Necessary properties missing in userto object, fetching full record', DEBUG_DEVELOPER);
 106         $eventdata->userto = core_user::get_user($eventdata->userto->id);
 107     }
 108
 109     $usertoisrealuser = (core_user::is_real_user($eventdata->userto->id) != false);
 110     // If recipient is internal user (noreply user), and emailstop is set then don't send any msg.
 111     if (!$usertoisrealuser && !empty($eventdata->userto->emailstop)) {
 112         debugging('Attempt to send msg to internal (noreply) user', DEBUG_NORMAL);
 113         return false;
 114     }
 115
 116     //after how long inactive should the user be considered logged off?
 117     if (isset($CFG->block_online_users_timetosee)) {
 118         $timetoshowusers = $CFG->block_online_users_timetosee * 60;
 119     } else {
 120         $timetoshowusers = 300;//5 minutes
 121     }
 122
 123     // Work out if the user is logged in or not
 124     if (!empty($eventdata->userto->lastaccess) && (time()-$timetoshowusers) < $eventdata->userto->lastaccess) {
 125         $userstate = 'loggedin';
 126     } else {
 127         $userstate = 'loggedoff';
 128     }
 129
 130     // Create the message object
 131     $savemessage = new stdClass();
 132     $savemessage->courseid          = $eventdata->courseid;
 133     $savemessage->useridfrom        = $eventdata->userfrom->id;
 134     $savemessage->useridto          = $eventdata->userto->id;
 135     $savemessage->subject           = $eventdata->subject;
 136     $savemessage->fullmessage       = $eventdata->fullmessage;
 137     $savemessage->fullmessageformat = $eventdata->fullmessageformat;
 138     $savemessage->fullmessagehtml   = $eventdata->fullmessagehtml;
 139     $savemessage->smallmessage      = $eventdata->smallmessage;
 140     $savemessage->notification      = $eventdata->notification;
 141     $savemessage->eventtype         = $eventdata->name;
 142     $savemessage->component         = $eventdata->component;
 143
 144     if (!empty($eventdata->contexturl)) {
 145         $savemessage->contexturl = (string)$eventdata->contexturl;
 146     } else {
 147         $savemessage->contexturl = null;
 148     }
 149
 150     if (!empty($eventdata->contexturlname)) {
 151         $savemessage->contexturlname = (string)$eventdata->contexturlname;
 152     } else {
 153         $savemessage->contexturlname = null;
 154     }
 155
 156     $savemessage->timecreated = time();
 157
 158     if (PHPUNIT_TEST and class_exists('phpunit_util')) {
 159         // Add some more tests to make sure the normal code can actually work.
 160         $componentdir = core_component::get_component_directory($eventdata->component);
 161         if (!$componentdir or !is_dir($componentdir)) {
 162             throw new coding_exception('Invalid component specified in message-send(): '.$eventdata->component);
 163         }
 164         if (!file_exists("$componentdir/db/messages.php")) {
 165             throw new coding_exception("$eventdata->component does not contain db/messages.php necessary for message_send()");
 166         }
 167         $messageproviders = null;
 168         include("$componentdir/db/messages.php");
 169         if (!isset($messageproviders[$eventdata->name])) {
 170             throw new coding_exception("Missing messaging defaults for event '$eventdata->name' in '$eventdata->component' messages.php file");
 171         }
 172         unset($componentdir);
 173         unset($messageproviders);
 174         // Now ask phpunit if it wants to catch this message.
 175         if (phpunit_util::is_redirecting_messages()) {
 176             $savemessage->timeread = time();
 177             $messageid = $DB->insert_record('message_read', $savemessage);
 178             $message = $DB->get_record('message_read', array('id'=>$messageid));
 179             phpunit_util::message_sent($message);
 180             return $messageid;
 181         }
 182     }
 183
 184     // Fetch enabled processors
 185     $processors = get_message_processors(true);
 186
 187     // Preset variables
 188     $processorlist = array();
 189     // Fill in the array of processors to be used based on default and user preferences
 190     foreach ($processors as $processor) {
 191         // Skip adding processors for internal user, if processor doesn't support sending message to internal user.
 192         if (!$usertoisrealuser && !$processor->object->can_send_to_any_users()) {
 193             continue;
 194         }
 195
 196         // First find out permissions
 197         $defaultpreference = $processor->name.'_provider_'.$preferencebase.'_permitted';
 198         if (isset($defaultpreferences->{$defaultpreference})) {
 199             $permitted = $defaultpreferences->{$defaultpreference};
 200         } else {
 201             // MDL-25114 They supplied an $eventdata->component $eventdata->name combination which doesn't
 202             // exist in the message_provider table (thus there is no default settings for them).
 203             $preferrormsg = "Could not load preference $defaultpreference. Make sure the component and name you supplied
 204                     to message_send() are valid.";
 205             throw new coding_exception($preferrormsg);
 206         }
 207
 208         // Find out if user has configured this output
 209         // Some processors cannot function without settings from the user
 210         $userisconfigured = $processor->object->is_user_configured($eventdata->userto);
 211
 212         // DEBUG: notify if we are forcing unconfigured output
 213         if ($permitted == 'forced' && !$userisconfigured) {
 214             debugging('Attempt to force message delivery to user who has "'.$processor->name.'" output unconfigured', DEBUG_NORMAL);
 215         }
 216
 217         // Populate the list of processors we will be using
 218         if ($permitted == 'forced' && $userisconfigured) {
 219             // An admin is forcing users to use this message processor. Use this processor unconditionally.
 220             $processorlist[] = $processor->name;
 221         } else if ($permitted == 'permitted' && $userisconfigured && !$eventdata->userto->emailstop) {
 222             // User has not disabled notifications
 223             // See if user set any notification preferences, otherwise use site default ones
 224             $userpreferencename = 'message_provider_'.$preferencebase.'_'.$userstate;
 225             if ($userpreference = get_user_preferences($userpreferencename, null, $eventdata->userto)) {
 226                 if (in_array($processor->name, explode(',', $userpreference))) {
 227                     $processorlist[] = $processor->name;
 228                 }
 229             } else if (isset($defaultpreferences->{$userpreferencename})) {
 230                 if (in_array($processor->name, explode(',', $defaultpreferences->{$userpreferencename}))) {
 231                     $processorlist[] = $processor->name;
 232                 }
 233             }
 234         }
 235     }
 236
 237     // Store unread message just in case we get a fatal error any time later.
 238     $savemessage->id = $DB->insert_record('message', $savemessage);
 239     $eventdata->savedmessageid = $savemessage->id;
 240
 241     // Let the manager do the sending or buffering when db transaction in progress.
 242     return \core\message\manager::send_message($eventdata, $savemessage, $processorlist);
 243 }
 244
 245
 246 /**
 247  * Updates the message_providers table with the current set of message providers
 248  *
 249  * @param string $component For example 'moodle', 'mod_forum' or 'block_quiz_results'
 250  * @return boolean True on success
 251  */
 252 function message_update_providers($component='moodle') {
 253     global $DB;
 254
 255     // load message providers from files
 256     $fileproviders = message_get_providers_from_file($component);
 257
 258     // load message providers from the database
 259     $dbproviders = message_get_providers_from_db($component);
 260
 261     foreach ($fileproviders as $messagename => $fileprovider) {
 262
 263         if (!empty($dbproviders[$messagename])) {   // Already exists in the database
 264             // check if capability has changed
 265             if ($dbproviders[$messagename]->capability == $fileprovider['capability']) {  // Same, so ignore
 266                 // exact same message provider already present in db, ignore this entry
 267                 unset($dbproviders[$messagename]);
 268                 continue;
 269
 270             } else {                                // Update existing one
 271                 $provider = new stdClass();
 272                 $provider->id         = $dbproviders[$messagename]->id;
 273                 $provider->capability = $fileprovider['capability'];
 274                 $DB->update_record('message_providers', $provider);
 275                 unset($dbproviders[$messagename]);
 276                 continue;
 277             }
 278
 279         } else {             // New message provider, add it
 280
 281             $provider = new stdClass();
 282             $provider->name       = $messagename;
 283             $provider->component  = $component;
 284             $provider->capability = $fileprovider['capability'];
 285
 286             $transaction = $DB->start_delegated_transaction();
 287             $DB->insert_record('message_providers', $provider);
 288             message_set_default_message_preference($component, $messagename, $fileprovider);
 289             $transaction->allow_commit();
 290         }
 291     }
 292
 293     foreach ($dbproviders as $dbprovider) {  // Delete old ones
 294         $DB->delete_records('message_providers', array('id' => $dbprovider->id));
 295         $DB->delete_records_select('config_plugins', "plugin = 'message' AND ".$DB->sql_like('name', '?', false), array("%_provider_{$component}_{$dbprovider->name}_%"));
 296         $DB->delete_records_select('user_preferences', $DB->sql_like('name', '?', false), array("message_provider_{$component}_{$dbprovider->name}_%"));
 297         cache_helper::invalidate_by_definition('core', 'config', array(), 'message');
 298     }
 299
 300     return true;
 301 }
 302
 303 /**
 304  * This function populates default message preferences for all existing providers
 305  * when the new message processor is added.
 306  *
 307  * @param string $processorname The name of message processor plugin (e.g. 'email', 'jabber')
 308  * @throws invalid_parameter_exception if $processorname does not exist in the database
 309  */
 310 function message_update_processors($processorname) {
 311     global $DB;
 312
 313     // validate if our processor exists
 314     $processor = $DB->get_records('message_processors', array('name' => $processorname));
 315     if (empty($processor)) {
 316         throw new invalid_parameter_exception();
 317     }
 318
 319     $providers = $DB->get_records_sql('SELECT DISTINCT component FROM {message_providers}');
 320
 321     $transaction = $DB->start_delegated_transaction();
 322     foreach ($providers as $provider) {
 323         // load message providers from files
 324         $fileproviders = message_get_providers_from_file($provider->component);
 325         foreach ($fileproviders as $messagename => $fileprovider) {
 326             message_set_default_message_preference($provider->component, $messagename, $fileprovider, $processorname);
 327         }
 328     }
 329     $transaction->allow_commit();
 330 }
 331
 332 /**
 333  * Setting default messaging preferences for particular message provider
 334  *
 335  * @param  string $component   The name of component (e.g. moodle, mod_forum, etc.)
 336  * @param  string $messagename The name of message provider
 337  * @param  array  $fileprovider The value of $messagename key in the array defined in plugin messages.php
 338  * @param  string $processorname The optional name of message processor
 339  */
 340 function message_set_default_message_preference($component, $messagename, $fileprovider, $processorname='') {
 341     global $DB;
 342
 343     // Fetch message processors
 344     $condition = null;
 345     // If we need to process a particular processor, set the select condition
 346     if (!empty($processorname)) {
 347        $condition = array('name' => $processorname);
 348     }
 349     $processors = $DB->get_records('message_processors', $condition);
 350
 351     // load default messaging preferences
 352     $defaultpreferences = get_message_output_default_preferences();
 353
 354     // Setting default preference
 355     $componentproviderbase = $component.'_'.$messagename;
 356     $loggedinpref = array();
 357     $loggedoffpref = array();
 358     // set 'permitted' preference first for each messaging processor
 359     foreach ($processors as $processor) {
 360         $preferencename = $processor->name.'_provider_'.$componentproviderbase.'_permitted';
 361         // if we do not have this setting yet, set it
 362         if (!isset($defaultpreferences->{$preferencename})) {
 363             // determine plugin default settings
 364             $plugindefault = 0;
 365             if (isset($fileprovider['defaults'][$processor->name])) {
 366                 $plugindefault = $fileprovider['defaults'][$processor->name];
 367             }
 368             // get string values of the settings
 369             list($permitted, $loggedin, $loggedoff) = translate_message_default_setting($plugindefault, $processor->name);
 370             // store default preferences for current processor
 371             set_config($preferencename, $permitted, 'message');
 372             // save loggedin/loggedoff settings
 373             if ($loggedin) {
 374                 $loggedinpref[] = $processor->name;
 375             }
 376             if ($loggedoff) {
 377                 $loggedoffpref[] = $processor->name;
 378             }
 379         }
 380     }
 381     // now set loggedin/loggedoff preferences
 382     if (!empty($loggedinpref)) {
 383         $preferencename = 'message_provider_'.$componentproviderbase.'_loggedin';
 384         if (isset($defaultpreferences->{$preferencename})) {
 385             // We have the default preferences for this message provider, which
 386             // likely means that we have been adding a new processor. Add defaults
 387             // to exisitng preferences.
 388             $loggedinpref = array_merge($loggedinpref, explode(',', $defaultpreferences->{$preferencename}));
 389         }
 390         set_config($preferencename, join(',', $loggedinpref), 'message');
 391     }
 392     if (!empty($loggedoffpref)) {
 393         $preferencename = 'message_provider_'.$componentproviderbase.'_loggedoff';
 394         if (isset($defaultpreferences->{$preferencename})) {
 395             // We have the default preferences for this message provider, which
 396             // likely means that we have been adding a new processor. Add defaults
 397             // to exisitng preferences.
 398             $loggedoffpref = array_merge($loggedoffpref, explode(',', $defaultpreferences->{$preferencename}));
 399         }
 400         set_config($preferencename, join(',', $loggedoffpref), 'message');
 401     }
 402 }
 403
 404 /**
 405  * Returns the active providers for the user specified, based on capability
 406  *
 407  * @param int $userid id of user
 408  * @return array An array of message providers
 409  */
 410 function message_get_providers_for_user($userid) {
 411     global $DB, $CFG;
 412
 413     $providers = get_message_providers();
 414
 415     // Ensure user is not allowed to configure instantmessage if it is globally disabled.
 416     if (!$CFG->messaging) {
 417         foreach ($providers as $providerid => $provider) {
 418             if ($provider->name == 'instantmessage') {
 419                 unset($providers[$providerid]);
 420                 break;
 421             }
 422         }
 423     }
 424
 425     // If the component is an enrolment plugin, check it is enabled
 426     foreach ($providers as $providerid => $provider) {
 427         list($type, $name) = core_component::normalize_component($provider->component);
 428         if ($type == 'enrol' && !enrol_is_enabled($name)) {
 429             unset($providers[$providerid]);
 430         }
 431     }
 432
 433     // Now we need to check capabilities. We need to eliminate the providers
 434     // where the user does not have the corresponding capability anywhere.
 435     // Here we deal with the common simple case of the user having the
 436     // capability in the system context. That handles $CFG->defaultuserroleid.
 437     // For the remaining providers/capabilities, we need to do a more complex
 438     // query involving all overrides everywhere.
 439     $unsureproviders = array();
 440     $unsurecapabilities = array();
 441     $systemcontext = context_system::instance();
 442     foreach ($providers as $providerid => $provider) {
 443         if (empty($provider->capability) || has_capability($provider->capability, $systemcontext, $userid)) {
 444             // The provider is relevant to this user.
 445             continue;
 446         }
 447
 448         $unsureproviders[$providerid] = $provider;
 449         $unsurecapabilities[$provider->capability] = 1;
 450         unset($providers[$providerid]);
 451     }
 452
 453     if (empty($unsureproviders)) {
 454         // More complex checks are not required.
 455         return $providers;
 456     }
 457
 458     // Now check the unsure capabilities.
 459     list($capcondition, $params) = $DB->get_in_or_equal(
 460             array_keys($unsurecapabilities), SQL_PARAMS_NAMED);
 461     $params['userid'] = $userid;
 462
 463     $sql = "SELECT DISTINCT rc.capability, 1
 464
 465               FROM {role_assignments} ra
 466               JOIN {context} actx ON actx.id = ra.contextid
 467               JOIN {role_capabilities} rc ON rc.roleid = ra.roleid
 468               JOIN {context} cctx ON cctx.id = rc.contextid
 469
 470              WHERE ra.userid = :userid
 471                AND rc.capability $capcondition
 472                AND rc.permission > 0
 473                AND (".$DB->sql_concat('actx.path', "'/'")." LIKE ".$DB->sql_concat('cctx.path', "'/%'").
 474                " OR ".$DB->sql_concat('cctx.path', "'/'")." LIKE ".$DB->sql_concat('actx.path', "'/%'").")";
 475
 476     if (!empty($CFG->defaultfrontpageroleid)) {
 477         $frontpagecontext = context_course::instance(SITEID);
 478
 479         list($capcondition2, $params2) = $DB->get_in_or_equal(
 480                 array_keys($unsurecapabilities), SQL_PARAMS_NAMED);
 481         $params = array_merge($params, $params2);
 482         $params['frontpageroleid'] = $CFG->defaultfrontpageroleid;
 483         $params['frontpagepathpattern'] = $frontpagecontext->path . '/';
 484
 485         $sql .= "
 486              UNION
 487
 488             SELECT DISTINCT rc.capability, 1
 489
 490               FROM {role_capabilities} rc
 491               JOIN {context} cctx ON cctx.id = rc.contextid
 492
 493              WHERE rc.roleid = :frontpageroleid
 494                AND rc.capability $capcondition2
 495                AND rc.permission > 0
 496                AND ".$DB->sql_concat('cctx.path', "'/'")." LIKE :frontpagepathpattern";
 497     }
 498
 499     $relevantcapabilities = $DB->get_records_sql_menu($sql, $params);
 500
 501     // Add back any providers based on the detailed capability check.
 502     foreach ($unsureproviders as $providerid => $provider) {
 503         if (array_key_exists($provider->capability, $relevantcapabilities)) {
 504             $providers[$providerid] = $provider;
 505         }
 506     }
 507
 508     return $providers;
 509 }
 510
 511 /**
 512  * Gets the message providers that are in the database for this component.
 513  *
 514  * This is an internal function used within messagelib.php
 515  *
 516  * @see message_update_providers()
 517  * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 518  * @return array An array of message providers
 519  */
 520 function message_get_providers_from_db($component) {
 521     global $DB;
 522
 523     return $DB->get_records('message_providers', array('component'=>$component), '', 'name, id, component, capability');  // Name is unique per component
 524 }
 525
 526 /**
 527  * Loads the messages definitions for a component from file
 528  *
 529  * If no messages are defined for the component, return an empty array.
 530  * This is an internal function used within messagelib.php
 531  *
 532  * @see message_update_providers()
 533  * @see message_update_processors()
 534  * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 535  * @return array An array of message providers or empty array if not exists
 536  */
 537 function message_get_providers_from_file($component) {
 538     $defpath = core_component::get_component_directory($component).'/db/messages.php';
 539
 540     $messageproviders = array();
 541
 542     if (file_exists($defpath)) {
 543         require($defpath);
 544     }
 545
 546     foreach ($messageproviders as $name => $messageprovider) {   // Fix up missing values if required
 547         if (empty($messageprovider['capability'])) {
 548             $messageproviders[$name]['capability'] = NULL;
 549         }
 550         if (empty($messageprovider['defaults'])) {
 551             $messageproviders[$name]['defaults'] = array();
 552         }
 553     }
 554
 555     return $messageproviders;
 556 }
 557
 558 /**
 559  * Remove all message providers for particular component and corresponding settings
 560  *
 561  * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 562  * @return void
 563  */
 564 function message_provider_uninstall($component) {
 565     global $DB;
 566
 567     $transaction = $DB->start_delegated_transaction();
 568     $DB->delete_records('message_providers', array('component' => $component));
 569     $DB->delete_records_select('config_plugins', "plugin = 'message' AND ".$DB->sql_like('name', '?', false), array("%_provider_{$component}_%"));
 570     $DB->delete_records_select('user_preferences', $DB->sql_like('name', '?', false), array("message_provider_{$component}_%"));
 571     $transaction->allow_commit();
 572     // Purge all messaging settings from the caches. They are stored by plugin so we have to clear all message settings.
 573     cache_helper::invalidate_by_definition('core', 'config', array(), 'message');
 574 }
 575
 576 /**
 577  * Uninstall a message processor
 578  *
 579  * @param string $name A message processor name like 'email', 'jabber'
 580  */
 581 function message_processor_uninstall($name) {
 582     global $DB;
 583
 584     $transaction = $DB->start_delegated_transaction();
 585     $DB->delete_records('message_processors', array('name' => $name));
 586     $DB->delete_records_select('config_plugins', "plugin = ?", array("message_{$name}"));
 587     // delete permission preferences only, we do not care about loggedin/loggedoff
 588     // defaults, they will be removed on the next attempt to update the preferences
 589     $DB->delete_records_select('config_plugins', "plugin = 'message' AND ".$DB->sql_like('name', '?', false), array("{$name}_provider_%"));
 590     $transaction->allow_commit();
 591     // Purge all messaging settings from the caches. They are stored by plugin so we have to clear all message settings.
 592     cache_helper::invalidate_by_definition('core', 'config', array(), array('message', "message_{$name}"));
 593 }