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 $messageid;
 181         }
 182     }
 183
 184     // Fetch enabled processors.
 185     // If we are dealing with a message some processors may want to handle it regardless of user and site settings.
 186     if (empty($savemessage->notification)) {
 187         $processors = array_filter(get_message_processors(false), function($processor) {
 188             if ($processor->object->force_process_messages()) {
 189                 return true;
 190             }
 191
 192             return ($processor->enabled && $processor->configured);
 193         });
 194     } else {
 195         $processors = get_message_processors(true);
 196     }
 197
 198     // Preset variables
 199     $processorlist = array();
 200     // Fill in the array of processors to be used based on default and user preferences
 201     foreach ($processors as $processor) {
 202         // Skip adding processors for internal user, if processor doesn't support sending message to internal user.
 203         if (!$usertoisrealuser && !$processor->object->can_send_to_any_users()) {
 204             continue;
 205         }
 206
 207         // First find out permissions
 208         $defaultpreference = $processor->name.'_provider_'.$preferencebase.'_permitted';
 209         if (isset($defaultpreferences->{$defaultpreference})) {
 210             $permitted = $defaultpreferences->{$defaultpreference};
 211         } else {
 212             // MDL-25114 They supplied an $eventdata->component $eventdata->name combination which doesn't
 213             // exist in the message_provider table (thus there is no default settings for them).
 214             $preferrormsg = "Could not load preference $defaultpreference. Make sure the component and name you supplied
 215                     to message_send() are valid.";
 216             throw new coding_exception($preferrormsg);
 217         }
 218
 219         // Find out if user has configured this output
 220         // Some processors cannot function without settings from the user
 221         $userisconfigured = $processor->object->is_user_configured($eventdata->userto);
 222
 223         // DEBUG: notify if we are forcing unconfigured output
 224         if ($permitted == 'forced' && !$userisconfigured) {
 225             debugging('Attempt to force message delivery to user who has "'.$processor->name.'" output unconfigured', DEBUG_NORMAL);
 226         }
 227
 228         // Populate the list of processors we will be using
 229         if (empty($savemessage->notification) && $processor->object->force_process_messages()) {
 230             $processorlist[] = $processor->name;
 231         } else if ($permitted == 'forced' && $userisconfigured) {
 232             // An admin is forcing users to use this message processor. Use this processor unconditionally.
 233             $processorlist[] = $processor->name;
 234         } else if ($permitted == 'permitted' && $userisconfigured && !$eventdata->userto->emailstop) {
 235             // User has not disabled notifications
 236             // See if user set any notification preferences, otherwise use site default ones
 237             $userpreferencename = 'message_provider_'.$preferencebase.'_'.$userstate;
 238             if ($userpreference = get_user_preferences($userpreferencename, null, $eventdata->userto)) {
 239                 if (in_array($processor->name, explode(',', $userpreference))) {
 240                     $processorlist[] = $processor->name;
 241                 }
 242             } else if (isset($defaultpreferences->{$userpreferencename})) {
 243                 if (in_array($processor->name, explode(',', $defaultpreferences->{$userpreferencename}))) {
 244                     $processorlist[] = $processor->name;
 245                 }
 246             }
 247         }
 248     }
 249
 250     // Only cache messages, not notifications.
 251     if (empty($savemessage->notification)) {
 252         // Cache the timecreated value of the last message between these two users.
 253         $cache = cache::make('core', 'message_time_last_message_between_users');
 254         $key = \core_message\helper::get_last_message_time_created_cache_key($savemessage->useridfrom,
 255             $savemessage->useridto);
 256         $cache->set($key, $savemessage->timecreated);
 257     }
 258
 259     // Store unread message just in case we get a fatal error any time later.
 260     $savemessage->id = $DB->insert_record('message', $savemessage);
 261     $eventdata->savedmessageid = $savemessage->id;
 262
 263     // Let the manager do the sending or buffering when db transaction in progress.
 264     return \core\message\manager::send_message($eventdata, $savemessage, $processorlist);
 265 }
 266
 267
 268 /**
 269  * Updates the message_providers table with the current set of message providers
 270  *
 271  * @param string $component For example 'moodle', 'mod_forum' or 'block_quiz_results'
 272  * @return boolean True on success
 273  */
 274 function message_update_providers($component='moodle') {
 275     global $DB;
 276
 277     // load message providers from files
 278     $fileproviders = message_get_providers_from_file($component);
 279
 280     // load message providers from the database
 281     $dbproviders = message_get_providers_from_db($component);
 282
 283     foreach ($fileproviders as $messagename => $fileprovider) {
 284
 285         if (!empty($dbproviders[$messagename])) {   // Already exists in the database
 286             // check if capability has changed
 287             if ($dbproviders[$messagename]->capability == $fileprovider['capability']) {  // Same, so ignore
 288                 // exact same message provider already present in db, ignore this entry
 289                 unset($dbproviders[$messagename]);
 290                 continue;
 291
 292             } else {                                // Update existing one
 293                 $provider = new stdClass();
 294                 $provider->id         = $dbproviders[$messagename]->id;
 295                 $provider->capability = $fileprovider['capability'];
 296                 $DB->update_record('message_providers', $provider);
 297                 unset($dbproviders[$messagename]);
 298                 continue;
 299             }
 300
 301         } else {             // New message provider, add it
 302
 303             $provider = new stdClass();
 304             $provider->name       = $messagename;
 305             $provider->component  = $component;
 306             $provider->capability = $fileprovider['capability'];
 307
 308             $transaction = $DB->start_delegated_transaction();
 309             $DB->insert_record('message_providers', $provider);
 310             message_set_default_message_preference($component, $messagename, $fileprovider);
 311             $transaction->allow_commit();
 312         }
 313     }
 314
 315     foreach ($dbproviders as $dbprovider) {  // Delete old ones
 316         $DB->delete_records('message_providers', array('id' => $dbprovider->id));
 317         $DB->delete_records_select('config_plugins', "plugin = 'message' AND ".$DB->sql_like('name', '?', false), array("%_provider_{$component}_{$dbprovider->name}_%"));
 318         $DB->delete_records_select('user_preferences', $DB->sql_like('name', '?', false), array("message_provider_{$component}_{$dbprovider->name}_%"));
 319         cache_helper::invalidate_by_definition('core', 'config', array(), 'message');
 320     }
 321
 322     return true;
 323 }
 324
 325 /**
 326  * This function populates default message preferences for all existing providers
 327  * when the new message processor is added.
 328  *
 329  * @param string $processorname The name of message processor plugin (e.g. 'email', 'jabber')
 330  * @throws invalid_parameter_exception if $processorname does not exist in the database
 331  */
 332 function message_update_processors($processorname) {
 333     global $DB;
 334
 335     // validate if our processor exists
 336     $processor = $DB->get_records('message_processors', array('name' => $processorname));
 337     if (empty($processor)) {
 338         throw new invalid_parameter_exception();
 339     }
 340
 341     $providers = $DB->get_records_sql('SELECT DISTINCT component FROM {message_providers}');
 342
 343     $transaction = $DB->start_delegated_transaction();
 344     foreach ($providers as $provider) {
 345         // load message providers from files
 346         $fileproviders = message_get_providers_from_file($provider->component);
 347         foreach ($fileproviders as $messagename => $fileprovider) {
 348             message_set_default_message_preference($provider->component, $messagename, $fileprovider, $processorname);
 349         }
 350     }
 351     $transaction->allow_commit();
 352 }
 353
 354 /**
 355  * Setting default messaging preferences for particular message provider
 356  *
 357  * @param  string $component   The name of component (e.g. moodle, mod_forum, etc.)
 358  * @param  string $messagename The name of message provider
 359  * @param  array  $fileprovider The value of $messagename key in the array defined in plugin messages.php
 360  * @param  string $processorname The optional name of message processor
 361  */
 362 function message_set_default_message_preference($component, $messagename, $fileprovider, $processorname='') {
 363     global $DB;
 364
 365     // Fetch message processors
 366     $condition = null;
 367     // If we need to process a particular processor, set the select condition
 368     if (!empty($processorname)) {
 369        $condition = array('name' => $processorname);
 370     }
 371     $processors = $DB->get_records('message_processors', $condition);
 372
 373     // load default messaging preferences
 374     $defaultpreferences = get_message_output_default_preferences();
 375
 376     // Setting default preference
 377     $componentproviderbase = $component.'_'.$messagename;
 378     $loggedinpref = array();
 379     $loggedoffpref = array();
 380     // set 'permitted' preference first for each messaging processor
 381     foreach ($processors as $processor) {
 382         $preferencename = $processor->name.'_provider_'.$componentproviderbase.'_permitted';
 383         // if we do not have this setting yet, set it
 384         if (!isset($defaultpreferences->{$preferencename})) {
 385             // determine plugin default settings
 386             $plugindefault = 0;
 387             if (isset($fileprovider['defaults'][$processor->name])) {
 388                 $plugindefault = $fileprovider['defaults'][$processor->name];
 389             }
 390             // get string values of the settings
 391             list($permitted, $loggedin, $loggedoff) = translate_message_default_setting($plugindefault, $processor->name);
 392             // store default preferences for current processor
 393             set_config($preferencename, $permitted, 'message');
 394             // save loggedin/loggedoff settings
 395             if ($loggedin) {
 396                 $loggedinpref[] = $processor->name;
 397             }
 398             if ($loggedoff) {
 399                 $loggedoffpref[] = $processor->name;
 400             }
 401         }
 402     }
 403     // now set loggedin/loggedoff preferences
 404     if (!empty($loggedinpref)) {
 405         $preferencename = 'message_provider_'.$componentproviderbase.'_loggedin';
 406         if (isset($defaultpreferences->{$preferencename})) {
 407             // We have the default preferences for this message provider, which
 408             // likely means that we have been adding a new processor. Add defaults
 409             // to exisitng preferences.
 410             $loggedinpref = array_merge($loggedinpref, explode(',', $defaultpreferences->{$preferencename}));
 411         }
 412         set_config($preferencename, join(',', $loggedinpref), 'message');
 413     }
 414     if (!empty($loggedoffpref)) {
 415         $preferencename = 'message_provider_'.$componentproviderbase.'_loggedoff';
 416         if (isset($defaultpreferences->{$preferencename})) {
 417             // We have the default preferences for this message provider, which
 418             // likely means that we have been adding a new processor. Add defaults
 419             // to exisitng preferences.
 420             $loggedoffpref = array_merge($loggedoffpref, explode(',', $defaultpreferences->{$preferencename}));
 421         }
 422         set_config($preferencename, join(',', $loggedoffpref), 'message');
 423     }
 424 }
 425
 426 /**
 427  * Returns the active providers for the user specified, based on capability
 428  *
 429  * @param int $userid id of user
 430  * @return array An array of message providers
 431  */
 432 function message_get_providers_for_user($userid) {
 433     global $DB, $CFG;
 434
 435     $providers = get_message_providers();
 436
 437     // Ensure user is not allowed to configure instantmessage if it is globally disabled.
 438     if (!$CFG->messaging) {
 439         foreach ($providers as $providerid => $provider) {
 440             if ($provider->name == 'instantmessage') {
 441                 unset($providers[$providerid]);
 442                 break;
 443             }
 444         }
 445     }
 446
 447     // If the component is an enrolment plugin, check it is enabled
 448     foreach ($providers as $providerid => $provider) {
 449         list($type, $name) = core_component::normalize_component($provider->component);
 450         if ($type == 'enrol' && !enrol_is_enabled($name)) {
 451             unset($providers[$providerid]);
 452         }
 453     }
 454
 455     // Now we need to check capabilities. We need to eliminate the providers
 456     // where the user does not have the corresponding capability anywhere.
 457     // Here we deal with the common simple case of the user having the
 458     // capability in the system context. That handles $CFG->defaultuserroleid.
 459     // For the remaining providers/capabilities, we need to do a more complex
 460     // query involving all overrides everywhere.
 461     $unsureproviders = array();
 462     $unsurecapabilities = array();
 463     $systemcontext = context_system::instance();
 464     foreach ($providers as $providerid => $provider) {
 465         if (empty($provider->capability) || has_capability($provider->capability, $systemcontext, $userid)) {
 466             // The provider is relevant to this user.
 467             continue;
 468         }
 469
 470         $unsureproviders[$providerid] = $provider;
 471         $unsurecapabilities[$provider->capability] = 1;
 472         unset($providers[$providerid]);
 473     }
 474
 475     if (empty($unsureproviders)) {
 476         // More complex checks are not required.
 477         return $providers;
 478     }
 479
 480     // Now check the unsure capabilities.
 481     list($capcondition, $params) = $DB->get_in_or_equal(
 482             array_keys($unsurecapabilities), SQL_PARAMS_NAMED);
 483     $params['userid'] = $userid;
 484
 485     $sql = "SELECT DISTINCT rc.capability, 1
 486
 487               FROM {role_assignments} ra
 488               JOIN {context} actx ON actx.id = ra.contextid
 489               JOIN {role_capabilities} rc ON rc.roleid = ra.roleid
 490               JOIN {context} cctx ON cctx.id = rc.contextid
 491
 492              WHERE ra.userid = :userid
 493                AND rc.capability $capcondition
 494                AND rc.permission > 0
 495                AND (".$DB->sql_concat('actx.path', "'/'")." LIKE ".$DB->sql_concat('cctx.path', "'/%'").
 496                " OR ".$DB->sql_concat('cctx.path', "'/'")." LIKE ".$DB->sql_concat('actx.path', "'/%'").")";
 497
 498     if (!empty($CFG->defaultfrontpageroleid)) {
 499         $frontpagecontext = context_course::instance(SITEID);
 500
 501         list($capcondition2, $params2) = $DB->get_in_or_equal(
 502                 array_keys($unsurecapabilities), SQL_PARAMS_NAMED);
 503         $params = array_merge($params, $params2);
 504         $params['frontpageroleid'] = $CFG->defaultfrontpageroleid;
 505         $params['frontpagepathpattern'] = $frontpagecontext->path . '/';
 506
 507         $sql .= "
 508              UNION
 509
 510             SELECT DISTINCT rc.capability, 1
 511
 512               FROM {role_capabilities} rc
 513               JOIN {context} cctx ON cctx.id = rc.contextid
 514
 515              WHERE rc.roleid = :frontpageroleid
 516                AND rc.capability $capcondition2
 517                AND rc.permission > 0
 518                AND ".$DB->sql_concat('cctx.path', "'/'")." LIKE :frontpagepathpattern";
 519     }
 520
 521     $relevantcapabilities = $DB->get_records_sql_menu($sql, $params);
 522
 523     // Add back any providers based on the detailed capability check.
 524     foreach ($unsureproviders as $providerid => $provider) {
 525         if (array_key_exists($provider->capability, $relevantcapabilities)) {
 526             $providers[$providerid] = $provider;
 527         }
 528     }
 529
 530     return $providers;
 531 }
 532
 533 /**
 534  * Gets the message providers that are in the database for this component.
 535  *
 536  * This is an internal function used within messagelib.php
 537  *
 538  * @see message_update_providers()
 539  * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 540  * @return array An array of message providers
 541  */
 542 function message_get_providers_from_db($component) {
 543     global $DB;
 544
 545     return $DB->get_records('message_providers', array('component'=>$component), '', 'name, id, component, capability');  // Name is unique per component
 546 }
 547
 548 /**
 549  * Loads the messages definitions for a component from file
 550  *
 551  * If no messages are defined for the component, return an empty array.
 552  * This is an internal function used within messagelib.php
 553  *
 554  * @see message_update_providers()
 555  * @see message_update_processors()
 556  * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 557  * @return array An array of message providers or empty array if not exists
 558  */
 559 function message_get_providers_from_file($component) {
 560     $defpath = core_component::get_component_directory($component).'/db/messages.php';
 561
 562     $messageproviders = array();
 563
 564     if (file_exists($defpath)) {
 565         require($defpath);
 566     }
 567
 568     foreach ($messageproviders as $name => $messageprovider) {   // Fix up missing values if required
 569         if (empty($messageprovider['capability'])) {
 570             $messageproviders[$name]['capability'] = NULL;
 571         }
 572         if (empty($messageprovider['defaults'])) {
 573             $messageproviders[$name]['defaults'] = array();
 574         }
 575     }
 576
 577     return $messageproviders;
 578 }
 579
 580 /**
 581  * Remove all message providers for particular component and corresponding settings
 582  *
 583  * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 584  * @return void
 585  */
 586 function message_provider_uninstall($component) {
 587     global $DB;
 588
 589     $transaction = $DB->start_delegated_transaction();
 590     $DB->delete_records('message_providers', array('component' => $component));
 591     $DB->delete_records_select('config_plugins', "plugin = 'message' AND ".$DB->sql_like('name', '?', false), array("%_provider_{$component}_%"));
 592     $DB->delete_records_select('user_preferences', $DB->sql_like('name', '?', false), array("message_provider_{$component}_%"));
 593     $transaction->allow_commit();
 594     // Purge all messaging settings from the caches. They are stored by plugin so we have to clear all message settings.
 595     cache_helper::invalidate_by_definition('core', 'config', array(), 'message');
 596 }
 597
 598 /**
 599  * Uninstall a message processor
 600  *
 601  * @param string $name A message processor name like 'email', 'jabber'
 602  */
 603 function message_processor_uninstall($name) {
 604     global $DB;
 605
 606     $transaction = $DB->start_delegated_transaction();
 607     $DB->delete_records('message_processors', array('name' => $name));
 608     $DB->delete_records_select('config_plugins', "plugin = ?", array("message_{$name}"));
 609     // delete permission preferences only, we do not care about loggedin/loggedoff
 610     // defaults, they will be removed on the next attempt to update the preferences
 611     $DB->delete_records_select('config_plugins', "plugin = 'message' AND ".$DB->sql_like('name', '?', false), array("{$name}_provider_%"));
 612     $transaction->allow_commit();
 613     // Purge all messaging settings from the caches. They are stored by plugin so we have to clear all message settings.
 614     cache_helper::invalidate_by_definition('core', 'config', array(), array('message', "message_{$name}"));
 615 }