Current Path : C:/Users/Mahmood/Desktop/moodle/mnet/service/enrol/ |
Current File : C:/Users/Mahmood/Desktop/moodle/mnet/service/enrol/locallib.php |
<?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 appname FROM {mnet_host} h JOIN {mnet_host2service} hs ON h.id = hs.hostid JOIN {mnet_service} s ON hs.serviceid = s.id JOIN {mnet_application} a ON h.applicationid = a.id WHERE s.name = 'mnet_enrol' AND h.deleted = 0 AND 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 appname FROM {mnet_host} h JOIN {mnet_host2service} hs ON h.id = hs.hostid JOIN {mnet_service} s ON hs.serviceid = s.id JOIN {mnet_application} a ON h.applicationid = a.id WHERE s.name = 'mnet_enrol' AND h.deleted = 0 AND 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 host require_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: currency if (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] = $course; } // prune stale data from cache if (!empty($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 data set_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-19219 return 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,id FROM {user} WHERE mnethostid = :mnetlocalhostid AND username $usql AND deleted = 0 AND confirmed = 1 ORDER BY $sort"; $usersbyusername = $DB->get_records_sql($sql, array_merge($params, $sortparams)); } else { $usersbyusername = array(); } // populate the returned list and update local cache of enrolment records foreach ($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] = $enrolment; } // prune stale enrolment records if (empty($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, $params); } // store the timestamp of the recent fetch, can be used for cache invalidate purposes set_config('lastfetchenrolments', time(), 'mnetservice_enrol'); // local cache successfully updated return true; } else { return serialize($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 {@link print_error()} * * 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} u JOIN {mnetservice_enrol_enrolments} e ON e.userid = u.id WHERE e.hostid = :hostid AND e.remotecourseid = :remotecourseid AND 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} u WHERE $wherecondition AND u.mnethostid = :mnetlocalhostid AND u.id $usql AND u.id NOT IN (SELECT e.userid FROM {mnetservice_enrol_enrolments} e WHERE (e.hostid = :hostid AND e.remotecourseid = :remotecourseid))"; list($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; } }