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<?php// This file is part of Moodle - http://moodle.org///// Moodle is free software: you can redistribute it and/or modify// it under the terms of the GNU General Public License as published by// the Free Software Foundation, either version 3 of the License, or// (at your option) any later version.//// Moodle is distributed in the hope that it will be useful,// but WITHOUT ANY WARRANTY; without even the implied warranty of// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the// GNU General Public License for more details.//// You should have received a copy of the GNU General Public License// along with Moodle. If not, see <http://www.gnu.org/licenses/>./*** Provides various useful functionality to plugins that offer or use this MNet service** Remote enrolment service is used by enrol_mnet plugin which publishes the server side* methods. The client side is accessible from the admin tree.** @package mnetservice* @subpackage enrol* @copyright 2010 David Mudrak <david@moodle.com>* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later*/defined('MOODLE_INTERNAL') || die();require_once($CFG->dirroot . '/user/selector/lib.php');/*** Singleton providing various functionality usable by plugin(s) implementing this MNet service*/class mnetservice_enrol {/** @var mnetservice_enrol holds the singleton instance. */protected static $singleton;/** @var caches the result of {@link self::get_remote_subscribers()} */protected $cachesubscribers = null;/** @var caches the result of {@link self::get_remote_publishers()} */protected $cachepublishers = null;/*** This is singleton, use {@link mnetservice_enrol::get_instance()}*/protected function __construct() {}/*** @return mnetservice_enrol singleton instance*/public static function get_instance() {if (is_null(self::$singleton)) {self::$singleton = new self();}return self::$singleton;}/*** Is this service enabled?** Currently, this checks if whole MNet is available. In the future, additional* checks can be done. Probably the field 'offer' should be checked but it does* not seem to be used so far.** @todo move this to some parent class once we have such* @return bool*/public function is_available() {global $CFG;if (empty($CFG->mnet_dispatcher_mode) || $CFG->mnet_dispatcher_mode !== 'strict') {return false;}return true;}/*** Returns a list of remote servers that can enrol their users into our courses** We must publish MNet service 'mnet_enrol' for the peers to allow them to enrol* their users into our courses.** @todo once the MNet core is refactored this may be part of a parent class* @todo the name of the service should be changed to the name of this plugin* @return array*/public function get_remote_subscribers() {global $DB;if (is_null($this->cachesubscribers)) {$sql = "SELECT DISTINCT h.id, h.name AS hostname, h.wwwroot AS hosturl,a.display_name AS appnameFROM {mnet_host} hJOIN {mnet_host2service} hs ON h.id = hs.hostidJOIN {mnet_service} s ON hs.serviceid = s.idJOIN {mnet_application} a ON h.applicationid = a.idWHERE s.name = 'mnet_enrol'AND h.deleted = 0AND hs.publish = 1";$this->cachesubscribers = $DB->get_records_sql($sql);}return $this->cachesubscribers;}/*** Returns a list of remote servers that offer their courses for our users** We must subscribe MNet service 'mnet_enrol' for the peers to allow our users to enrol* into their courses.** @todo once the MNet core is refactored this may be part of a parent class* @todo the name of the service should be changed to the name of this plugin* @return array*/public function get_remote_publishers() {global $DB;if (is_null($this->cachepublishers)) {$sql = "SELECT DISTINCT h.id, h.name AS hostname, h.wwwroot AS hosturl,a.display_name AS appnameFROM {mnet_host} hJOIN {mnet_host2service} hs ON h.id = hs.hostidJOIN {mnet_service} s ON hs.serviceid = s.idJOIN {mnet_application} a ON h.applicationid = a.idWHERE s.name = 'mnet_enrol'AND h.deleted = 0AND hs.subscribe = 1";$this->cachepublishers = $DB->get_records_sql($sql);}return $this->cachepublishers;}/*** Fetches the information about the courses available on remote host for our students** The information about remote courses available for us is cached in {mnetservice_enrol_courses}.* This method either returns the cached information (typically when displaying the list to* students) or fetch fresh data via new XML-RPC request (which updates the local cache, too).* The lifetime of the cache is 1 day, so even if $usecache is set to true, the cache will be* re-populated if we did not fetch from any server (not only the currently requested one)* for some time.** @param id $mnethostid MNet remote host id* @param bool $usecache use cached data or invoke new XML-RPC?* @uses mnet_xmlrpc_client Invokes XML-RPC request if the cache is not used* @return array|string returned list or serialized array of mnet error messages*/public function get_remote_courses($mnethostid, $usecache=true) {global $CFG, $DB; // $CFG needed!$lastfetchcourses = get_config('mnetservice_enrol', 'lastfetchcourses');if (empty($lastfetchcourses) or (time()-$lastfetchcourses > DAYSECS)) {$usecache = false;}if ($usecache) {return $DB->get_records('mnetservice_enrol_courses', array('hostid' => $mnethostid), 'sortorder, shortname');}// do not use cache - fetch fresh list from remote MNet hostrequire_once $CFG->dirroot.'/mnet/xmlrpc/client.php';$peer = new mnet_peer();if (!$peer->set_id($mnethostid)) {return serialize(array('unknown mnet peer'));}$request = new mnet_xmlrpc_client();$request->set_method('enrol/mnet/enrol.php/available_courses');if ($request->send($peer)) {$list = array();$response = $request->response;// get the currently cached courses key'd on remote id - only need remoteid and id fields$cachedcourses = $DB->get_records('mnetservice_enrol_courses', array('hostid' => $mnethostid), 'remoteid', 'remoteid, id');foreach ($response as &$remote) {$course = new stdclass(); // record in our local cache$course->hostid = $mnethostid;$course->remoteid = (int)$remote['remoteid'];$course->categoryid = (int)$remote['cat_id'];$course->categoryname = substr($remote['cat_name'], 0, 255);$course->sortorder = (int)$remote['sortorder'];$course->fullname = substr($remote['fullname'], 0, 254);$course->shortname = substr($remote['shortname'], 0, 100);$course->idnumber = substr($remote['idnumber'], 0, 100);$course->summary = $remote['summary'];$course->summaryformat = empty($remote['summaryformat']) ? FORMAT_MOODLE : (int)$remote['summaryformat'];$course->startdate = (int)$remote['startdate'];$course->roleid = (int)$remote['defaultroleid'];$course->rolename = substr($remote['defaultrolename'], 0, 255);// We do not cache the following fields returned from peer in 2.0 any more// not cached: cat_description// not cached: cat_descriptionformat// not cached: cost// not cached: currencyif (empty($cachedcourses[$course->remoteid])) {$course->id = $DB->insert_record('mnetservice_enrol_courses', $course);} else {$course->id = $cachedcourses[$course->remoteid]->id;$DB->update_record('mnetservice_enrol_courses', $course);}$list[$course->remoteid] = $course;}// prune stale data from cacheif (!empty($cachedcourses)) {foreach ($cachedcourses as $cachedcourse) {if (!empty($list[$cachedcourse->remoteid])) {unset($cachedcourses[$cachedcourse->remoteid]);}}$staleremoteids = array_keys($cachedcourses);if (!empty($staleremoteids)) {list($sql, $params) = $DB->get_in_or_equal($staleremoteids, SQL_PARAMS_NAMED);$select = "hostid=:hostid AND remoteid $sql";$params['hostid'] = $mnethostid;$DB->delete_records_select('mnetservice_enrol_courses', $select, $params);}}// and return the fresh dataset_config('lastfetchcourses', time(), 'mnetservice_enrol');return $list;} else {return serialize($request->error);}}/*** Updates local cache about enrolments of our users in remote courses** The remote course must allow enrolments via our Remote enrolment service client.* Because of legacy design of data structure returned by XML-RPC code, only one* user enrolment per course is returned by 1.9 MNet servers. This may be an issue* if the user is enrolled multiple times by various enrolment plugins. MNet 2.0* servers do not use user name as array keys - they do not need to due to side* effect of MDL-19219.** @param id $mnethostid MNet remote host id* @param int $remotecourseid ID of the course at the remote host* @param bool $usecache use cached data or invoke new XML-RPC?* @uses mnet_xmlrpc_client Invokes XML-RPC request* @return bool|string true if success or serialized array of mnet error messages*/public function req_course_enrolments($mnethostid, $remotecourseid) {global $CFG, $DB; // $CFG needed!require_once $CFG->dirroot.'/mnet/xmlrpc/client.php';if (!$DB->record_exists('mnetservice_enrol_courses', array('hostid'=>$mnethostid, 'remoteid'=>$remotecourseid))) {return serialize(array('course not available for remote enrolments'));}$peer = new mnet_peer();if (!$peer->set_id($mnethostid)) {return serialize(array('unknown mnet peer'));}$request = new mnet_xmlrpc_client();$request->set_method('enrol/mnet/enrol.php/course_enrolments');$request->add_param($remotecourseid, 'int');if ($request->send($peer)) {$list = array();$response = $request->response;// prepare a table mapping usernames of our users to their ids$usernames = array();foreach ($response as $unused => $remote) {if (!isset($remote['username'])) {// see MDL-19219return serialize(array('remote host running old version of mnet server - does not return username attribute'));}if ($remote['username'] == 'guest') { // we can not use $CFG->siteguest here// do not try nasty things you bastard!continue;}$usernames[$remote['username']] = $remote['username'];}if (!empty($usernames)) {list($usql, $params) = $DB->get_in_or_equal($usernames, SQL_PARAMS_NAMED);list($sort, $sortparams) = users_order_by_sql();$params['mnetlocalhostid'] = $CFG->mnet_localhost_id;$sql = "SELECT username,idFROM {user}WHERE mnethostid = :mnetlocalhostidAND username $usqlAND deleted = 0AND confirmed = 1ORDER BY $sort";$usersbyusername = $DB->get_records_sql($sql, array_merge($params, $sortparams));} else {$usersbyusername = array();}// populate the returned list and update local cache of enrolment recordsforeach ($response as $remote) {if (empty($usersbyusername[$remote['username']])) {// we do not know this user or she is deleted or not confirmed or is 'guest'continue;}$enrolment = new stdclass();$enrolment->hostid = $mnethostid;$enrolment->userid = $usersbyusername[$remote['username']]->id;$enrolment->remotecourseid = $remotecourseid;$enrolment->rolename = $remote['name']; // $remote['shortname'] not used$enrolment->enroltime = $remote['timemodified'];$enrolment->enroltype = $remote['enrol'];$current = $DB->get_record('mnetservice_enrol_enrolments', array('hostid'=>$enrolment->hostid, 'userid'=>$enrolment->userid,'remotecourseid'=>$enrolment->remotecourseid, 'enroltype'=>$enrolment->enroltype), 'id, enroltime');if (empty($current)) {$enrolment->id = $DB->insert_record('mnetservice_enrol_enrolments', $enrolment);} else {$enrolment->id = $current->id;if ($current->enroltime != $enrolment->enroltime) {$DB->update_record('mnetservice_enrol_enrolments', $enrolment);}}$list[$enrolment->id] = $enrolment;}// prune stale enrolment recordsif (empty($list)) {$DB->delete_records('mnetservice_enrol_enrolments', array('hostid'=>$mnethostid, 'remotecourseid'=>$remotecourseid));} else {list($isql, $params) = $DB->get_in_or_equal(array_keys($list), SQL_PARAMS_NAMED, 'param', false);$params['hostid'] = $mnethostid;$params['remotecourseid'] = $remotecourseid;$select = "hostid = :hostid AND remotecourseid = :remotecourseid AND id $isql";$DB->delete_records_select('mnetservice_enrol_enrolments', $select, $params);}// store the timestamp of the recent fetch, can be used for cache invalidate purposesset_config('lastfetchenrolments', time(), 'mnetservice_enrol');// local cache successfully updatedreturn true;} else {return serialize($request->error);}}/*** Send request to enrol our user to the remote course** Updates our remote enrolments cache if the enrolment was successful.** @uses mnet_xmlrpc_client Invokes XML-RPC request* @param object $user our user* @param object $remotecourse record from mnetservice_enrol_courses table* @return true|string true if success, error message from the remote host otherwise*/public function req_enrol_user(stdclass $user, stdclass $remotecourse) {global $CFG, $DB;require_once($CFG->dirroot.'/mnet/xmlrpc/client.php');$peer = new mnet_peer();$peer->set_id($remotecourse->hostid);$request = new mnet_xmlrpc_client();$request->set_method('enrol/mnet/enrol.php/enrol_user');$request->add_param(mnet_strip_user((array)$user, mnet_fields_to_send($peer)));$request->add_param($remotecourse->remoteid);if ($request->send($peer) === true) {if ($request->response === true) {// cache the enrolment information in our table$enrolment = new stdclass();$enrolment->hostid = $peer->id;$enrolment->userid = $user->id;$enrolment->remotecourseid = $remotecourse->remoteid;$enrolment->enroltype = 'mnet';// $enrolment->rolename not known now, must be re-fetched// $enrolment->enroltime not known now, must be re-fetched$DB->insert_record('mnetservice_enrol_enrolments', $enrolment);return true;} else {return serialize(array('invalid response: '.print_r($request->response, true)));}} else {return serialize($request->error);}}/*** Send request to unenrol our user from the remote course** Updates our remote enrolments cache if the unenrolment was successful.** @uses mnet_xmlrpc_client Invokes XML-RPC request* @param object $user our user* @param object $remotecourse record from mnetservice_enrol_courses table* @return true|string true if success, error message from the remote host otherwise*/public function req_unenrol_user(stdclass $user, stdclass $remotecourse) {global $CFG, $DB;require_once($CFG->dirroot.'/mnet/xmlrpc/client.php');$peer = new mnet_peer();$peer->set_id($remotecourse->hostid);$request = new mnet_xmlrpc_client();$request->set_method('enrol/mnet/enrol.php/unenrol_user');$request->add_param($user->username);$request->add_param($remotecourse->remoteid);if ($request->send($peer) === true) {if ($request->response === true) {// clear the cached information$DB->delete_records('mnetservice_enrol_enrolments',array('hostid'=>$peer->id, 'userid'=>$user->id, 'remotecourseid'=>$remotecourse->remoteid, 'enroltype'=>'mnet'));return true;} else {return serialize(array('invalid response: '.print_r($request->response, true)));}} else {return serialize($request->error);}}/*** Prepares error messages returned by our XML-RPC requests to be send as debug info to {@see \moodle_exception()}** MNet client-side methods in this class return request error as serialized array.** @param string $error serialized array* @return string*/public function format_error_message($errormsg) {$errors = unserialize($errormsg);$output = 'mnet_xmlrpc_client request returned errors:'."\n";foreach ($errors as $error) {$output .= "$error\n";}return $output;}}/*** Selector of our users enrolled into remote course via enrol_mnet plugin*/class mnetservice_enrol_existing_users_selector extends user_selector_base {/** @var id of the MNet peer */protected $hostid;/** @var id of the course at the remote server */protected $remotecourseid;public function __construct($name, $options) {$this->hostid = $options['hostid'];$this->remotecourseid = $options['remotecourseid'];parent::__construct($name, $options);}/*** Find our users currently enrolled into the remote course** @param string $search* @return array*/public function find_users($search) {global $DB;list($wherecondition, $params) = $this->search_sql($search, 'u');$params['hostid'] = $this->hostid;$params['remotecourseid'] = $this->remotecourseid;$fields = "SELECT ".$this->required_fields_sql("u");$countfields = "SELECT COUNT(1)";$sql = " FROM {user} uJOIN {mnetservice_enrol_enrolments} e ON e.userid = u.idWHERE e.hostid = :hostid AND e.remotecourseid = :remotecourseidAND e.enroltype = 'mnet'AND $wherecondition";list($sort, $sortparams) = users_order_by_sql('u');$order = " ORDER BY $sort";if (!$this->is_validating()) {$potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);if ($potentialmemberscount > 100) {return $this->too_many_results($search, $potentialmemberscount);}}$availableusers = $DB->get_records_sql($fields . $sql . $order, array_merge($params, $sortparams));if (empty($availableusers)) {return array();}if ($search) {$groupname = get_string('enrolledusersmatching', 'enrol', $search);} else {$groupname = get_string('enrolledusers', 'enrol');}return array($groupname => $availableusers);}protected function get_options() {$options = parent::get_options();$options['hostid'] = $this->hostid;$options['remotecourseid'] = $this->remotecourseid;$options['file'] = 'mnet/service/enrol/locallib.php';return $options;}}/*** Selector of our users who could be enrolled into a remote course via their enrol_mnet*/class mnetservice_enrol_potential_users_selector extends user_selector_base {/** @var id of the MNet peer */protected $hostid;/** @var id of the course at the remote server */protected $remotecourseid;public function __construct($name, $options) {$this->hostid = $options['hostid'];$this->remotecourseid = $options['remotecourseid'];parent::__construct($name, $options);}/*** Find our users who could be enrolled into the remote course** Our users must have 'moodle/site:mnetlogintoremote' capability assigned.* Remote users, guests, deleted and not confirmed users are not returned.** @param string $search* @return array*/public function find_users($search) {global $CFG, $DB;$systemcontext = context_system::instance();$userids = get_users_by_capability($systemcontext, 'moodle/site:mnetlogintoremote', 'u.id');if (empty($userids)) {return array();}list($usql, $uparams) = $DB->get_in_or_equal(array_keys($userids), SQL_PARAMS_NAMED, 'uid');list($wherecondition, $params) = $this->search_sql($search, 'u');$params = array_merge($params, $uparams);$params['hostid'] = $this->hostid;$params['remotecourseid'] = $this->remotecourseid;$params['mnetlocalhostid'] = $CFG->mnet_localhost_id;$fields = "SELECT ".$this->required_fields_sql("u");$countfields = "SELECT COUNT(1)";$sql = " FROM {user} uWHERE $whereconditionAND u.mnethostid = :mnetlocalhostidAND u.id $usqlAND u.id NOT IN (SELECT e.useridFROM {mnetservice_enrol_enrolments} eWHERE (e.hostid = :hostid AND e.remotecourseid = :remotecourseid))";list($sort, $sortparams) = users_order_by_sql('u');$order = " ORDER BY $sort";if (!$this->is_validating()) {$potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);if ($potentialmemberscount > 100) {return $this->too_many_results($search, $potentialmemberscount);}}$availableusers = $DB->get_records_sql($fields . $sql . $order, array_merge($params, $sortparams));if (empty($availableusers)) {return array();}if ($search) {$groupname = get_string('enrolcandidatesmatching', 'enrol', $search);} else {$groupname = get_string('enrolcandidates', 'enrol');}return array($groupname => $availableusers);}protected function get_options() {$options = parent::get_options();$options['hostid'] = $this->hostid;$options['remotecourseid'] = $this->remotecourseid;$options['file'] = 'mnet/service/enrol/locallib.php';return $options;}}