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  * @category message
  54  * @param \core\message\message $eventdata information about the message (component, userfrom, userto, ...)
  55  * @return mixed the integer ID of the new message or false if there was a problem with submitted data
  56  */
  57 function message_send(\core\message\message $eventdata) {
  58     global $CFG, $DB, $SITE;
  59
  60     //new message ID to return
  61     $messageid = false;
  62
  63     // Fetch default (site) preferences
  64     $defaultpreferences = get_message_output_default_preferences();
  65     $preferencebase = $eventdata->component.'_'.$eventdata->name;
  66
  67     // If the message provider is disabled via preferences, then don't send the message.
  68     if (!empty($defaultpreferences->{$preferencebase.'_disable'})) {
  69         return $messageid;
  70     }
  71
  72     // By default a message is a notification. Only personal/private messages aren't notifications.
  73     if (!isset($eventdata->notification)) {
  74         $eventdata->notification = 1;
  75     }
  76
  77     if (!is_object($eventdata->userfrom)) {
  78         $eventdata->userfrom = core_user::get_user($eventdata->userfrom);
  79     }
  80     if (!$eventdata->userfrom) {
  81         debugging('Attempt to send msg from unknown user', DEBUG_NORMAL);
  82         return false;
  83     }
  84
  85     // Legacy messages (FROM a single user TO a single user) must be converted into conversation messages.
  86     // Then, these will be passed through the conversation messages code below.
  87     if (!$eventdata->notification && !$eventdata->convid) {
  88         // If messaging is disabled at the site level, then the 'instantmessage' provider is always disabled.
  89         // Given this is the only 'message' type message provider, we can exit now if this is the case.
  90         // Don't waste processing time trying to work out the other conversation member, if it's an individual
  91         // conversation, just throw a generic debugging notice and return.
  92         if (empty($CFG->messaging) || $eventdata->component !== 'moodle' || $eventdata->name !== 'instantmessage') {
  93             debugging('Attempt to send msg from a provider '.$eventdata->component.'/'.$eventdata->name.
  94                 ' that is inactive or not allowed for the user id='.$eventdata->userto->id, DEBUG_NORMAL);
  95             return false;
  96         }
  97
  98         if (!is_object($eventdata->userto)) {
  99             $eventdata->userto = core_user::get_user($eventdata->userto);
 100         }
 101         if (!$eventdata->userto) {
 102             debugging('Attempt to send msg to unknown user', DEBUG_NORMAL);
 103             return false;
 104         }
 105
 106         // Verify all necessary data fields are present.
 107         if (!isset($eventdata->userto->auth) or !isset($eventdata->userto->suspended)
 108             or !isset($eventdata->userto->deleted) or !isset($eventdata->userto->emailstop)) {
 109
 110             debugging('Necessary properties missing in userto object, fetching full record', DEBUG_DEVELOPER);
 111             $eventdata->userto = core_user::get_user($eventdata->userto->id);
 112         }
 113
 114         $usertoisrealuser = (core_user::is_real_user($eventdata->userto->id) != false);
 115         // If recipient is internal user (noreply user), and emailstop is set then don't send any msg.
 116         if (!$usertoisrealuser && !empty($eventdata->userto->emailstop)) {
 117             debugging('Attempt to send msg to internal (noreply) user', DEBUG_NORMAL);
 118             return false;
 119         }
 120
 121         if (!$conversationid = \core_message\api::get_conversation_between_users([$eventdata->userfrom->id,
 122                                                                                   $eventdata->userto->id])) {
 123             $conversation = \core_message\api::create_conversation(
 124                 \core_message\api::MESSAGE_CONVERSATION_TYPE_INDIVIDUAL,
 125                 [
 126                     $eventdata->userfrom->id,
 127                     $eventdata->userto->id
 128                 ]
 129             );
 130         }
 131         // We either have found a conversation, or created one.
 132         $conversationid = $conversationid ? $conversationid : $conversation->id;
 133         $eventdata->convid = $conversationid;
 134     }
 135
 136     // This is a message directed to a conversation, not a specific user as was the way in legacy messaging.
 137     // The above code has adapted the legacy messages into conversation messages.
 138     // We must call send_message_to_conversation(), which handles per-member processor iteration and triggers
 139     // a per-conversation event.
 140     // All eventdata for messages should now have a convid, as we fixed this above.
 141     if (!$eventdata->notification) {
 142
 143         // Only one message will be saved to the DB.
 144         $conversationid = $eventdata->convid;
 145         $table = 'messages';
 146         $tabledata = new stdClass();
 147         $tabledata->courseid = $eventdata->courseid;
 148         $tabledata->useridfrom = $eventdata->userfrom->id;
 149         $tabledata->conversationid = $conversationid;
 150         $tabledata->subject = $eventdata->subject;
 151         $tabledata->fullmessage = $eventdata->fullmessage;
 152         $tabledata->fullmessageformat = $eventdata->fullmessageformat;
 153         $tabledata->fullmessagehtml = $eventdata->fullmessagehtml;
 154         $tabledata->smallmessage = $eventdata->smallmessage;
 155         $tabledata->timecreated = time();
 156
 157         if ($messageid = message_handle_phpunit_redirection($eventdata, $table, $tabledata)) {
 158             return $messageid;
 159         }
 160
 161         // Cache messages.
 162         if (!empty($eventdata->convid)) {
 163             // Cache the timecreated value of the last message in this conversation.
 164             $cache = cache::make('core', 'message_time_last_message_between_users');
 165             $key = \core_message\helper::get_last_message_time_created_cache_key($eventdata->convid);
 166             $cache->set($key, $tabledata->timecreated);
 167         }
 168
 169         // Store unread message just in case we get a fatal error any time later.
 170         $tabledata->id = $DB->insert_record($table, $tabledata);
 171         $eventdata->savedmessageid = $tabledata->id;
 172
 173         return \core\message\manager::send_message_to_conversation($eventdata, $tabledata);
 174     }
 175
 176     // Else the message is a notification.
 177     if (!is_object($eventdata->userto)) {
 178         $eventdata->userto = core_user::get_user($eventdata->userto);
 179     }
 180     if (!$eventdata->userto) {
 181         debugging('Attempt to send msg to unknown user', DEBUG_NORMAL);
 182         return false;
 183     }
 184
 185     // If the provider's component is disabled or the user can't receive messages from it, don't send the message.
 186     $isproviderallowed = false;
 187     foreach (message_get_providers_for_user($eventdata->userto->id) as $provider) {
 188         if ($provider->component === $eventdata->component && $provider->name === $eventdata->name) {
 189             $isproviderallowed = true;
 190             break;
 191         }
 192     }
 193     if (!$isproviderallowed) {
 194         debugging('Attempt to send msg from a provider '.$eventdata->component.'/'.$eventdata->name.
 195             ' that is inactive or not allowed for the user id='.$eventdata->userto->id, DEBUG_NORMAL);
 196         return false;
 197     }
 198
 199     // Verify all necessary data fields are present.
 200     if (!isset($eventdata->userto->auth) or !isset($eventdata->userto->suspended)
 201             or !isset($eventdata->userto->deleted) or !isset($eventdata->userto->emailstop)) {
 202
 203         debugging('Necessary properties missing in userto object, fetching full record', DEBUG_DEVELOPER);
 204         $eventdata->userto = core_user::get_user($eventdata->userto->id);
 205     }
 206
 207     $usertoisrealuser = (core_user::is_real_user($eventdata->userto->id) != false);
 208     // If recipient is internal user (noreply user), and emailstop is set then don't send any msg.
 209     if (!$usertoisrealuser && !empty($eventdata->userto->emailstop)) {
 210         debugging('Attempt to send msg to internal (noreply) user', DEBUG_NORMAL);
 211         return false;
 212     }
 213
 214     //after how long inactive should the user be considered logged off?
 215     if (isset($CFG->block_online_users_timetosee)) {
 216         $timetoshowusers = $CFG->block_online_users_timetosee * 60;
 217     } else {
 218         $timetoshowusers = 300;//5 minutes
 219     }
 220
 221     // Work out if the user is logged in or not
 222     if (!empty($eventdata->userto->lastaccess) && (time()-$timetoshowusers) < $eventdata->userto->lastaccess) {
 223         $userstate = 'loggedin';
 224     } else {
 225         $userstate = 'loggedoff';
 226     }
 227
 228     // Check if we are creating a notification or message.
 229     $table = 'notifications';
 230
 231     $tabledata = new stdClass();
 232     $tabledata->useridfrom = $eventdata->userfrom->id;
 233     $tabledata->useridto = $eventdata->userto->id;
 234     $tabledata->subject = $eventdata->subject;
 235     $tabledata->fullmessage = $eventdata->fullmessage;
 236     $tabledata->fullmessageformat = $eventdata->fullmessageformat;
 237     $tabledata->fullmessagehtml = $eventdata->fullmessagehtml;
 238     $tabledata->smallmessage = $eventdata->smallmessage;
 239     $tabledata->eventtype = $eventdata->name;
 240     $tabledata->component = $eventdata->component;
 241     $tabledata->timecreated = time();
 242     if (!empty($eventdata->contexturl)) {
 243         $tabledata->contexturl = (string)$eventdata->contexturl;
 244     } else {
 245         $tabledata->contexturl = null;
 246     }
 247
 248     if (!empty($eventdata->contexturlname)) {
 249         $tabledata->contexturlname = (string)$eventdata->contexturlname;
 250     } else {
 251         $tabledata->contexturlname = null;
 252     }
 253
 254     if ($messageid = message_handle_phpunit_redirection($eventdata, $table, $tabledata)) {
 255         return $messageid;
 256     }
 257
 258     // Fetch enabled processors.
 259     $processors = get_message_processors(true);
 260
 261     // Preset variables
 262     $processorlist = array();
 263     // Fill in the array of processors to be used based on default and user preferences
 264     foreach ($processors as $processor) {
 265         // Skip adding processors for internal user, if processor doesn't support sending message to internal user.
 266         if (!$usertoisrealuser && !$processor->object->can_send_to_any_users()) {
 267             continue;
 268         }
 269
 270         // First find out permissions
 271         $defaultpreference = $processor->name.'_provider_'.$preferencebase.'_permitted';
 272         if (isset($defaultpreferences->{$defaultpreference})) {
 273             $permitted = $defaultpreferences->{$defaultpreference};
 274         } else {
 275             // MDL-25114 They supplied an $eventdata->component $eventdata->name combination which doesn't
 276             // exist in the message_provider table (thus there is no default settings for them).
 277             $preferrormsg = "Could not load preference $defaultpreference. Make sure the component and name you supplied
 278                     to message_send() are valid.";
 279             throw new coding_exception($preferrormsg);
 280         }
 281
 282         // Find out if user has configured this output
 283         // Some processors cannot function without settings from the user
 284         $userisconfigured = $processor->object->is_user_configured($eventdata->userto);
 285
 286         // DEBUG: notify if we are forcing unconfigured output
 287         if ($permitted == 'forced' && !$userisconfigured) {
 288             debugging('Attempt to force message delivery to user who has "'.$processor->name.'" output unconfigured', DEBUG_NORMAL);
 289         }
 290
 291         // Populate the list of processors we will be using
 292         if ($permitted == 'forced' && $userisconfigured) {
 293             // An admin is forcing users to use this message processor. Use this processor unconditionally.
 294             $processorlist[] = $processor->name;
 295         } else if ($permitted == 'permitted' && $userisconfigured && !$eventdata->userto->emailstop) {
 296             // User has not disabled notifications
 297             // See if user set any notification preferences, otherwise use site default ones
 298             $userpreferencename = 'message_provider_'.$preferencebase.'_'.$userstate;
 299             if ($userpreference = get_user_preferences($userpreferencename, null, $eventdata->userto)) {
 300                 if (in_array($processor->name, explode(',', $userpreference))) {
 301                     $processorlist[] = $processor->name;
 302                 }
 303             } else if (isset($defaultpreferences->{$userpreferencename})) {
 304                 if (in_array($processor->name, explode(',', $defaultpreferences->{$userpreferencename}))) {
 305                     $processorlist[] = $processor->name;
 306                 }
 307             }
 308         }
 309     }
 310
 311     // Store unread message just in case we get a fatal error any time later.
 312     $tabledata->id = $DB->insert_record($table, $tabledata);
 313     $eventdata->savedmessageid = $tabledata->id;
 314
 315     // Let the manager do the sending or buffering when db transaction in progress.
 316     return \core\message\manager::send_message($eventdata, $tabledata, $processorlist);
 317 }
 318
 319 /**
 320  * Helper method containing the PHPUnit specific code, used to redirect and capture messages/notifications.
 321  *
 322  * @param \core\message\message $eventdata the message object
 323  * @param string $table the table to store the tabledata in, either messages or notifications.
 324  * @param stdClass $tabledata the data to be stored when creating the message/notification.
 325  * @return int the id of the stored message.
 326  */
 327 function message_handle_phpunit_redirection(\core\message\message $eventdata, string $table, \stdClass $tabledata) {
 328     global $DB;
 329     if (PHPUNIT_TEST and class_exists('phpunit_util')) {
 330         // Add some more tests to make sure the normal code can actually work.
 331         $componentdir = core_component::get_component_directory($eventdata->component);
 332         if (!$componentdir or !is_dir($componentdir)) {
 333             throw new coding_exception('Invalid component specified in message-send(): '.$eventdata->component);
 334         }
 335         if (!file_exists("$componentdir/db/messages.php")) {
 336             throw new coding_exception("$eventdata->component does not contain db/messages.php necessary for message_send()");
 337         }
 338         $messageproviders = null;
 339         include("$componentdir/db/messages.php");
 340         if (!isset($messageproviders[$eventdata->name])) {
 341             throw new coding_exception("Missing messaging defaults for event '$eventdata->name' in '$eventdata->component' " .
 342                 "messages.php file");
 343         }
 344         unset($componentdir);
 345         unset($messageproviders);
 346         // Now ask phpunit if it wants to catch this message.
 347         if (phpunit_util::is_redirecting_messages()) {
 348             $messageid = $DB->insert_record($table, $tabledata);
 349             $message = $DB->get_record($table, array('id' => $messageid));
 350
 351             if ($eventdata->notification) {
 352                 // Add the useridto attribute for BC.
 353                 $message->useridto = $eventdata->userto->id;
 354
 355                 // Mark the notification as read.
 356                 \core_message\api::mark_notification_as_read($message);
 357             } else {
 358                 // Add the useridto attribute for BC.
 359                 if (isset($eventdata->userto)) {
 360                     $message->useridto = $eventdata->userto->id;
 361                 }
 362                 // Mark the message as read for each of the other users.
 363                 $sql = "SELECT u.*
 364                   FROM {message_conversation_members} mcm
 365                   JOIN {user} u
 366                     ON (mcm.conversationid = :convid AND u.id = mcm.userid AND u.id != :userid)";
 367                 $otherusers = $DB->get_records_sql($sql, ['convid' => $eventdata->convid, 'userid' => $eventdata->userfrom->id]);
 368                 foreach ($otherusers as $othermember) {
 369                     \core_message\api::mark_message_as_read($othermember->id, $message);
 370                 }
 371             }
 372
 373             // Unit tests need this detail.
 374             $message->notification = $eventdata->notification;
 375             phpunit_util::message_sent($message);
 376             return $messageid;
 377         }
 378     }
 379 }
 380
 381 /**
 382  * Updates the message_providers table with the current set of message providers
 383  *
 384  * @param string $component For example 'moodle', 'mod_forum' or 'block_quiz_results'
 385  * @return boolean True on success
 386  */
 387 function message_update_providers($component='moodle') {
 388     global $DB;
 389
 390     // load message providers from files
 391     $fileproviders = message_get_providers_from_file($component);
 392
 393     // load message providers from the database
 394     $dbproviders = message_get_providers_from_db($component);
 395
 396     foreach ($fileproviders as $messagename => $fileprovider) {
 397
 398         if (!empty($dbproviders[$messagename])) {   // Already exists in the database
 399             // check if capability has changed
 400             if ($dbproviders[$messagename]->capability == $fileprovider['capability']) {  // Same, so ignore
 401                 // exact same message provider already present in db, ignore this entry
 402                 unset($dbproviders[$messagename]);
 403                 continue;
 404
 405             } else {                                // Update existing one
 406                 $provider = new stdClass();
 407                 $provider->id         = $dbproviders[$messagename]->id;
 408                 $provider->capability = $fileprovider['capability'];
 409                 $DB->update_record('message_providers', $provider);
 410                 unset($dbproviders[$messagename]);
 411                 continue;
 412             }
 413
 414         } else {             // New message provider, add it
 415
 416             $provider = new stdClass();
 417             $provider->name       = $messagename;
 418             $provider->component  = $component;
 419             $provider->capability = $fileprovider['capability'];
 420
 421             $transaction = $DB->start_delegated_transaction();
 422             $DB->insert_record('message_providers', $provider);
 423             message_set_default_message_preference($component, $messagename, $fileprovider);
 424             $transaction->allow_commit();
 425         }
 426     }
 427
 428     foreach ($dbproviders as $dbprovider) {  // Delete old ones
 429         $DB->delete_records('message_providers', array('id' => $dbprovider->id));
 430         $DB->delete_records_select('config_plugins', "plugin = 'message' AND ".$DB->sql_like('name', '?', false), array("%_provider_{$component}_{$dbprovider->name}_%"));
 431         $DB->delete_records_select('user_preferences', $DB->sql_like('name', '?', false), array("message_provider_{$component}_{$dbprovider->name}_%"));
 432         cache_helper::invalidate_by_definition('core', 'config', array(), 'message');
 433     }
 434
 435     return true;
 436 }
 437
 438 /**
 439  * This function populates default message preferences for all existing providers
 440  * when the new message processor is added.
 441  *
 442  * @param string $processorname The name of message processor plugin (e.g. 'email', 'jabber')
 443  * @throws invalid_parameter_exception if $processorname does not exist in the database
 444  */
 445 function message_update_processors($processorname) {
 446     global $DB;
 447
 448     // validate if our processor exists
 449     $processor = $DB->get_records('message_processors', array('name' => $processorname));
 450     if (empty($processor)) {
 451         throw new invalid_parameter_exception();
 452     }
 453
 454     $providers = $DB->get_records_sql('SELECT DISTINCT component FROM {message_providers}');
 455
 456     $transaction = $DB->start_delegated_transaction();
 457     foreach ($providers as $provider) {
 458         // load message providers from files
 459         $fileproviders = message_get_providers_from_file($provider->component);
 460         foreach ($fileproviders as $messagename => $fileprovider) {
 461             message_set_default_message_preference($provider->component, $messagename, $fileprovider, $processorname);
 462         }
 463     }
 464     $transaction->allow_commit();
 465 }
 466
 467 /**
 468  * Setting default messaging preferences for particular message provider
 469  *
 470  * @param  string $component   The name of component (e.g. moodle, mod_forum, etc.)
 471  * @param  string $messagename The name of message provider
 472  * @param  array  $fileprovider The value of $messagename key in the array defined in plugin messages.php
 473  * @param  string $processorname The optional name of message processor
 474  */
 475 function message_set_default_message_preference($component, $messagename, $fileprovider, $processorname='') {
 476     global $DB;
 477
 478     // Fetch message processors
 479     $condition = null;
 480     // If we need to process a particular processor, set the select condition
 481     if (!empty($processorname)) {
 482        $condition = array('name' => $processorname);
 483     }
 484     $processors = $DB->get_records('message_processors', $condition);
 485
 486     // load default messaging preferences
 487     $defaultpreferences = get_message_output_default_preferences();
 488
 489     // Setting default preference
 490     $componentproviderbase = $component.'_'.$messagename;
 491     $loggedinpref = array();
 492     $loggedoffpref = array();
 493     // set 'permitted' preference first for each messaging processor
 494     foreach ($processors as $processor) {
 495         $preferencename = $processor->name.'_provider_'.$componentproviderbase.'_permitted';
 496         // if we do not have this setting yet, set it
 497         if (!isset($defaultpreferences->{$preferencename})) {
 498             // determine plugin default settings
 499             $plugindefault = 0;
 500             if (isset($fileprovider['defaults'][$processor->name])) {
 501                 $plugindefault = $fileprovider['defaults'][$processor->name];
 502             }
 503             // get string values of the settings
 504             list($permitted, $loggedin, $loggedoff) = translate_message_default_setting($plugindefault, $processor->name);
 505             // store default preferences for current processor
 506             set_config($preferencename, $permitted, 'message');
 507             // save loggedin/loggedoff settings
 508             if ($loggedin) {
 509                 $loggedinpref[] = $processor->name;
 510             }
 511             if ($loggedoff) {
 512                 $loggedoffpref[] = $processor->name;
 513             }
 514         }
 515     }
 516     // now set loggedin/loggedoff preferences
 517     if (!empty($loggedinpref)) {
 518         $preferencename = 'message_provider_'.$componentproviderbase.'_loggedin';
 519         if (isset($defaultpreferences->{$preferencename})) {
 520             // We have the default preferences for this message provider, which
 521             // likely means that we have been adding a new processor. Add defaults
 522             // to exisitng preferences.
 523             $loggedinpref = array_merge($loggedinpref, explode(',', $defaultpreferences->{$preferencename}));
 524         }
 525         set_config($preferencename, join(',', $loggedinpref), 'message');
 526     }
 527     if (!empty($loggedoffpref)) {
 528         $preferencename = 'message_provider_'.$componentproviderbase.'_loggedoff';
 529         if (isset($defaultpreferences->{$preferencename})) {
 530             // We have the default preferences for this message provider, which
 531             // likely means that we have been adding a new processor. Add defaults
 532             // to exisitng preferences.
 533             $loggedoffpref = array_merge($loggedoffpref, explode(',', $defaultpreferences->{$preferencename}));
 534         }
 535         set_config($preferencename, join(',', $loggedoffpref), 'message');
 536     }
 537 }
 538
 539 /**
 540  * Returns the active providers for the user specified, based on capability
 541  *
 542  * @param int $userid id of user
 543  * @return array An array of message providers
 544  */
 545 function message_get_providers_for_user($userid) {
 546     global $DB, $CFG;
 547
 548     $providers = get_message_providers();
 549
 550     // Ensure user is not allowed to configure instantmessage if it is globally disabled.
 551     if (!$CFG->messaging) {
 552         foreach ($providers as $providerid => $provider) {
 553             if ($provider->name == 'instantmessage') {
 554                 unset($providers[$providerid]);
 555                 break;
 556             }
 557         }
 558     }
 559
 560     // If the component is an enrolment plugin, check it is enabled
 561     foreach ($providers as $providerid => $provider) {
 562         list($type, $name) = core_component::normalize_component($provider->component);
 563         if ($type == 'enrol' && !enrol_is_enabled($name)) {
 564             unset($providers[$providerid]);
 565         }
 566     }
 567
 568     // Now we need to check capabilities. We need to eliminate the providers
 569     // where the user does not have the corresponding capability anywhere.
 570     // Here we deal with the common simple case of the user having the
 571     // capability in the system context. That handles $CFG->defaultuserroleid.
 572     // For the remaining providers/capabilities, we need to do a more complex
 573     // query involving all overrides everywhere.
 574     $unsureproviders = array();
 575     $unsurecapabilities = array();
 576     $systemcontext = context_system::instance();
 577     foreach ($providers as $providerid => $provider) {
 578         if (empty($provider->capability) || has_capability($provider->capability, $systemcontext, $userid)) {
 579             // The provider is relevant to this user.
 580             continue;
 581         }
 582
 583         $unsureproviders[$providerid] = $provider;
 584         $unsurecapabilities[$provider->capability] = 1;
 585         unset($providers[$providerid]);
 586     }
 587
 588     if (empty($unsureproviders)) {
 589         // More complex checks are not required.
 590         return $providers;
 591     }
 592
 593     // Now check the unsure capabilities.
 594     list($capcondition, $params) = $DB->get_in_or_equal(
 595             array_keys($unsurecapabilities), SQL_PARAMS_NAMED);
 596     $params['userid'] = $userid;
 597
 598     $sql = "SELECT DISTINCT rc.capability, 1
 599
 600               FROM {role_assignments} ra
 601               JOIN {context} actx ON actx.id = ra.contextid
 602               JOIN {role_capabilities} rc ON rc.roleid = ra.roleid
 603               JOIN {context} cctx ON cctx.id = rc.contextid
 604
 605              WHERE ra.userid = :userid
 606                AND rc.capability $capcondition
 607                AND rc.permission > 0
 608                AND (".$DB->sql_concat('actx.path', "'/'")." LIKE ".$DB->sql_concat('cctx.path', "'/%'").
 609                " OR ".$DB->sql_concat('cctx.path', "'/'")." LIKE ".$DB->sql_concat('actx.path', "'/%'").")";
 610
 611     if (!empty($CFG->defaultfrontpageroleid)) {
 612         $frontpagecontext = context_course::instance(SITEID);
 613
 614         list($capcondition2, $params2) = $DB->get_in_or_equal(
 615                 array_keys($unsurecapabilities), SQL_PARAMS_NAMED);
 616         $params = array_merge($params, $params2);
 617         $params['frontpageroleid'] = $CFG->defaultfrontpageroleid;
 618         $params['frontpagepathpattern'] = $frontpagecontext->path . '/';
 619
 620         $sql .= "
 621              UNION
 622
 623             SELECT DISTINCT rc.capability, 1
 624
 625               FROM {role_capabilities} rc
 626               JOIN {context} cctx ON cctx.id = rc.contextid
 627
 628              WHERE rc.roleid = :frontpageroleid
 629                AND rc.capability $capcondition2
 630                AND rc.permission > 0
 631                AND ".$DB->sql_concat('cctx.path', "'/'")." LIKE :frontpagepathpattern";
 632     }
 633
 634     $relevantcapabilities = $DB->get_records_sql_menu($sql, $params);
 635
 636     // Add back any providers based on the detailed capability check.
 637     foreach ($unsureproviders as $providerid => $provider) {
 638         if (array_key_exists($provider->capability, $relevantcapabilities)) {
 639             $providers[$providerid] = $provider;
 640         }
 641     }
 642
 643     return $providers;
 644 }
 645
 646 /**
 647  * Gets the message providers that are in the database for this component.
 648  *
 649  * This is an internal function used within messagelib.php
 650  *
 651  * @see message_update_providers()
 652  * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 653  * @return array An array of message providers
 654  */
 655 function message_get_providers_from_db($component) {
 656     global $DB;
 657
 658     return $DB->get_records('message_providers', array('component'=>$component), '', 'name, id, component, capability');  // Name is unique per component
 659 }
 660
 661 /**
 662  * Loads the messages definitions for a component from file
 663  *
 664  * If no messages are defined for the component, return an empty array.
 665  * This is an internal function used within messagelib.php
 666  *
 667  * @see message_update_providers()
 668  * @see message_update_processors()
 669  * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 670  * @return array An array of message providers or empty array if not exists
 671  */
 672 function message_get_providers_from_file($component) {
 673     $defpath = core_component::get_component_directory($component).'/db/messages.php';
 674
 675     $messageproviders = array();
 676
 677     if (file_exists($defpath)) {
 678         require($defpath);
 679     }
 680
 681     foreach ($messageproviders as $name => $messageprovider) {   // Fix up missing values if required
 682         if (empty($messageprovider['capability'])) {
 683             $messageproviders[$name]['capability'] = NULL;
 684         }
 685         if (empty($messageprovider['defaults'])) {
 686             $messageproviders[$name]['defaults'] = array();
 687         }
 688     }
 689
 690     return $messageproviders;
 691 }
 692
 693 /**
 694  * Remove all message providers for particular component and corresponding settings
 695  *
 696  * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 697  * @return void
 698  */
 699 function message_provider_uninstall($component) {
 700     global $DB;
 701
 702     $transaction = $DB->start_delegated_transaction();
 703     $DB->delete_records('message_providers', array('component' => $component));
 704     $DB->delete_records_select('config_plugins', "plugin = 'message' AND ".$DB->sql_like('name', '?', false), array("%_provider_{$component}_%"));
 705     $DB->delete_records_select('user_preferences', $DB->sql_like('name', '?', false), array("message_provider_{$component}_%"));
 706     $transaction->allow_commit();
 707     // Purge all messaging settings from the caches. They are stored by plugin so we have to clear all message settings.
 708     cache_helper::invalidate_by_definition('core', 'config', array(), 'message');
 709 }
 710
 711 /**
 712  * Uninstall a message processor
 713  *
 714  * @param string $name A message processor name like 'email', 'jabber'
 715  */
 716 function message_processor_uninstall($name) {
 717     global $DB;
 718
 719     $transaction = $DB->start_delegated_transaction();
 720     $DB->delete_records('message_processors', array('name' => $name));
 721     $DB->delete_records_select('config_plugins', "plugin = ?", array("message_{$name}"));
 722     // delete permission preferences only, we do not care about loggedin/loggedoff
 723     // defaults, they will be removed on the next attempt to update the preferences
 724     $DB->delete_records_select('config_plugins', "plugin = 'message' AND ".$DB->sql_like('name', '?', false), array("{$name}_provider_%"));
 725     $transaction->allow_commit();
 726     // Purge all messaging settings from the caches. They are stored by plugin so we have to clear all message settings.
 727     cache_helper::invalidate_by_definition('core', 'config', array(), array('message', "message_{$name}"));
 728 }