enrol/locallib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * This file contains the course_enrolment_manager class which is used to interface
  20  * with the functions that exist in enrollib.php in relation to a single course.
  21  *
  22  * @package    core
  23  * @subpackage enrol
  24  * @copyright  2010 Sam Hemelryk
  25  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26  */
  27
  28 defined('MOODLE_INTERNAL') || die();
  29
  30 /**
  31  * This class provides a targeted tied together means of interfacing the enrolment
  32  * tasks together with a course.
  33  *
  34  * It is provided as a convenience more than anything else.
  35  *
  36  * @copyright 2010 Sam Hemelryk
  37  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  38  */
  39 class course_enrolment_manager {
  40
  41     /**
  42      * The course context
  43      * @var stdClass
  44      */
  45     protected $context;
  46     /**
  47      * The course we are managing enrolments for
  48      * @var stdClass
  49      */
  50     protected $course = null;
  51     /**
  52      * Limits the focus of the manager to one enrolment plugin instance
  53      * @var string
  54      */
  55     protected $instancefilter = null;
  56
  57     /**
  58      * The total number of users enrolled in the course
  59      * Populated by course_enrolment_manager::get_total_users
  60      * @var int
  61      */
  62     protected $totalusers = null;
  63     /**
  64      * An array of users currently enrolled in the course
  65      * Populated by course_enrolment_manager::get_users
  66      * @var array
  67      */
  68     protected $users = array();
  69
  70     /**
  71      * An array of users who have roles within this course but who have not
  72      * been enrolled in the course
  73      * @var array
  74      */
  75     protected $otherusers = array();
  76
  77     /**
  78      * The total number of users who hold a role within the course but who
  79      * arn't enrolled.
  80      * @var int
  81      */
  82     protected $totalotherusers = null;
  83
  84     /**
  85      * The current moodle_page object
  86      * @var moodle_page
  87      */
  88     protected $moodlepage = null;
  89
  90     /**#@+
  91      * These variables are used to cache the information this class uses
  92      * please never use these directly instead use their get_ counterparts.
  93      * @access private
  94      * @var array
  95      */
  96     private $_instancessql = null;
  97     private $_instances = null;
  98     private $_inames = null;
  99     private $_plugins = null;
 100     private $_allplugins = null;
 101     private $_roles = null;
 102     private $_assignableroles = null;
 103     private $_assignablerolesothers = null;
 104     private $_groups = null;
 105     /**#@-*/
 106
 107     /**
 108      * Constructs the course enrolment manager
 109      *
 110      * @param moodle_page $moodlepage
 111      * @param stdClass $course
 112      * @param string $instancefilter
 113      */
 114     public function __construct(moodle_page $moodlepage, $course, $instancefilter = null) {
 115         $this->moodlepage = $moodlepage;
 116         $this->context = context_course::instance($course->id);
 117         $this->course = $course;
 118         $this->instancefilter = $instancefilter;
 119     }
 120
 121     /**
 122      * Returns the current moodle page
 123      * @return moodle_page
 124      */
 125     public function get_moodlepage() {
 126         return $this->moodlepage;
 127     }
 128
 129     /**
 130      * Returns the total number of enrolled users in the course.
 131      *
 132      * If a filter was specificed this will be the total number of users enrolled
 133      * in this course by means of that instance.
 134      *
 135      * @global moodle_database $DB
 136      * @return int
 137      */
 138     public function get_total_users() {
 139         global $DB;
 140         if ($this->totalusers === null) {
 141             list($instancessql, $params, $filter) = $this->get_instance_sql();
 142             $sqltotal = "SELECT COUNT(DISTINCT u.id)
 143                            FROM {user} u
 144                            JOIN {user_enrolments} ue ON (ue.userid = u.id  AND ue.enrolid $instancessql)
 145                            JOIN {enrol} e ON (e.id = ue.enrolid)";
 146             $this->totalusers = (int)$DB->count_records_sql($sqltotal, $params);
 147         }
 148         return $this->totalusers;
 149     }
 150
 151     /**
 152      * Returns the total number of enrolled users in the course.
 153      *
 154      * If a filter was specificed this will be the total number of users enrolled
 155      * in this course by means of that instance.
 156      *
 157      * @global moodle_database $DB
 158      * @return int
 159      */
 160     public function get_total_other_users() {
 161         global $DB;
 162         if ($this->totalotherusers === null) {
 163             list($ctxcondition, $params) = $DB->get_in_or_equal(get_parent_contexts($this->context, true), SQL_PARAMS_NAMED, 'ctx');
 164             $params['courseid'] = $this->course->id;
 165             $sql = "SELECT COUNT(DISTINCT u.id)
 166                       FROM {role_assignments} ra
 167                       JOIN {user} u ON u.id = ra.userid
 168                       JOIN {context} ctx ON ra.contextid = ctx.id
 169                  LEFT JOIN (
 170                            SELECT ue.id, ue.userid
 171                              FROM {user_enrolments} ue
 172                         LEFT JOIN {enrol} e ON e.id=ue.enrolid
 173                             WHERE e.courseid = :courseid
 174                          ) ue ON ue.userid=u.id
 175                      WHERE ctx.id $ctxcondition AND
 176                            ue.id IS NULL";
 177             $this->totalotherusers = (int)$DB->count_records_sql($sql, $params);
 178         }
 179         return $this->totalotherusers;
 180     }
 181
 182     /**
 183      * Gets all of the users enrolled in this course.
 184      *
 185      * If a filter was specified this will be the users who were enrolled
 186      * in this course by means of that instance.
 187      *
 188      * @global moodle_database $DB
 189      * @param string $sort
 190      * @param string $direction ASC or DESC
 191      * @param int $page First page should be 0
 192      * @param int $perpage Defaults to 25
 193      * @return array
 194      */
 195     public function get_users($sort, $direction='ASC', $page=0, $perpage=25) {
 196         global $DB;
 197         if ($direction !== 'ASC') {
 198             $direction = 'DESC';
 199         }
 200         $key = md5("$sort-$direction-$page-$perpage");
 201         if (!array_key_exists($key, $this->users)) {
 202             list($instancessql, $params, $filter) = $this->get_instance_sql();
 203             $extrafields = get_extra_user_fields($this->get_context());
 204             $extrafields[] = 'lastaccess';
 205             $ufields = user_picture::fields('u', $extrafields);
 206             $sql = "SELECT DISTINCT $ufields, ul.timeaccess AS lastseen
 207                       FROM {user} u
 208                       JOIN {user_enrolments} ue ON (ue.userid = u.id  AND ue.enrolid $instancessql)
 209                       JOIN {enrol} e ON (e.id = ue.enrolid)
 210                  LEFT JOIN {user_lastaccess} ul ON (ul.courseid = e.courseid AND ul.userid = u.id)";
 211             if ($sort === 'firstname') {
 212                 $sql .= " ORDER BY u.firstname $direction, u.lastname $direction";
 213             } else if ($sort === 'lastname') {
 214                 $sql .= " ORDER BY u.lastname $direction, u.firstname $direction";
 215             } else if ($sort === 'email') {
 216                 $sql .= " ORDER BY u.email $direction, u.lastname $direction, u.firstname $direction";
 217             } else if ($sort === 'lastseen') {
 218                 $sql .= " ORDER BY ul.timeaccess $direction, u.lastname $direction, u.firstname $direction";
 219             }
 220             $this->users[$key] = $DB->get_records_sql($sql, $params, $page*$perpage, $perpage);
 221         }
 222         return $this->users[$key];
 223     }
 224
 225     /**
 226      * Gets and array of other users.
 227      *
 228      * Other users are users who have been assigned roles or inherited roles
 229      * within this course but who have not been enrolled in the course
 230      *
 231      * @global moodle_database $DB
 232      * @param string $sort
 233      * @param string $direction
 234      * @param int $page
 235      * @param int $perpage
 236      * @return array
 237      */
 238     public function get_other_users($sort, $direction='ASC', $page=0, $perpage=25) {
 239         global $DB;
 240         if ($direction !== 'ASC') {
 241             $direction = 'DESC';
 242         }
 243         $key = md5("$sort-$direction-$page-$perpage");
 244         if (!array_key_exists($key, $this->otherusers)) {
 245             list($ctxcondition, $params) = $DB->get_in_or_equal(get_parent_contexts($this->context, true), SQL_PARAMS_NAMED, 'ctx');
 246             $params['courseid'] = $this->course->id;
 247             $params['cid'] = $this->course->id;
 248             $sql = "SELECT ra.id as raid, ra.contextid, ra.component, ctx.contextlevel, ra.roleid, u.*, ue.lastseen
 249                     FROM {role_assignments} ra
 250                     JOIN {user} u ON u.id = ra.userid
 251                     JOIN {context} ctx ON ra.contextid = ctx.id
 252                LEFT JOIN (
 253                        SELECT ue.id, ue.userid, ul.timeaccess AS lastseen
 254                          FROM {user_enrolments} ue
 255                     LEFT JOIN {enrol} e ON e.id=ue.enrolid
 256                     LEFT JOIN {user_lastaccess} ul ON (ul.courseid = e.courseid AND ul.userid = ue.userid)
 257                         WHERE e.courseid = :courseid
 258                        ) ue ON ue.userid=u.id
 259                    WHERE ctx.id $ctxcondition AND
 260                          ue.id IS NULL
 261                 ORDER BY u.$sort $direction, ctx.depth DESC";
 262             $this->otherusers[$key] = $DB->get_records_sql($sql, $params, $page*$perpage, $perpage);
 263         }
 264         return $this->otherusers[$key];
 265     }
 266
 267     /**
 268      * Helper method used by {@link get_potential_users()} and {@link search_other_users()}.
 269      *
 270      * @param string $search the search term, if any.
 271      * @param bool $searchanywhere Can the search term be anywhere, or must it be at the start.
 272      * @return array with three elements:
 273      *     string list of fields to SELECT,
 274      *     string contents of SQL WHERE clause,
 275      *     array query params. Note that the SQL snippets use named parameters.
 276      */
 277     protected function get_basic_search_conditions($search, $searchanywhere) {
 278         global $DB, $CFG;
 279
 280         // Add some additional sensible conditions
 281         $tests = array("u.id <> :guestid", 'u.deleted = 0', 'u.confirmed = 1');
 282         $params = array('guestid' => $CFG->siteguest);
 283         if (!empty($search)) {
 284             $conditions = get_extra_user_fields($this->get_context());
 285             $conditions[] = 'u.firstname';
 286             $conditions[] = 'u.lastname';
 287             $conditions[] = $DB->sql_fullname('u.firstname', 'u.lastname');
 288             if ($searchanywhere) {
 289                 $searchparam = '%' . $search . '%';
 290             } else {
 291                 $searchparam = $search . '%';
 292             }
 293             $i = 0;
 294             foreach ($conditions as $key => $condition) {
 295                 $conditions[$key] = $DB->sql_like($condition, ":con{$i}00", false);
 296                 $params["con{$i}00"] = $searchparam;
 297                 $i++;
 298             }
 299             $tests[] = '(' . implode(' OR ', $conditions) . ')';
 300         }
 301         $wherecondition = implode(' AND ', $tests);
 302
 303         $extrafields = get_extra_user_fields($this->get_context(), array('username', 'lastaccess'));
 304         $extrafields[] = 'username';
 305         $extrafields[] = 'lastaccess';
 306         $ufields = user_picture::fields('u', $extrafields);
 307
 308         return array($ufields, $params, $wherecondition);
 309     }
 310
 311     /**
 312      * Helper method used by {@link get_potential_users()} and {@link search_other_users()}.
 313      *
 314      * @param string $search the search string, if any.
 315      * @param string $fields the first bit of the SQL when returning some users.
 316      * @param string $countfields fhe first bit of the SQL when counting the users.
 317      * @param string $sql the bulk of the SQL statement.
 318      * @param array $params query parameters.
 319      * @param int $page which page number of the results to show.
 320      * @param int $perpage number of users per page.
 321      * @param int $addedenrollment number of users added to enrollment.
 322      * @return array with two elememts:
 323      *      int total number of users matching the search.
 324      *      array of user objects returned by the query.
 325      */
 326     protected function execute_search_queries($search, $fields, $countfields, $sql, array $params, $page, $perpage, $addedenrollment=0) {
 327         global $DB, $CFG;
 328
 329         list($sort, $sortparams) = users_order_by_sql('u', $search, $this->get_context());
 330         $order = ' ORDER BY ' . $sort;
 331
 332         $totalusers = $DB->count_records_sql($countfields . $sql, $params);
 333         $availableusers = $DB->get_records_sql($fields . $sql . $order,
 334                 array_merge($params, $sortparams), ($page*$perpage) - $addedenrollment, $perpage);
 335
 336         return array('totalusers' => $totalusers, 'users' => $availableusers);
 337     }
 338
 339     /**
 340      * Gets an array of the users that can be enrolled in this course.
 341      *
 342      * @global moodle_database $DB
 343      * @param int $enrolid
 344      * @param string $search
 345      * @param bool $searchanywhere
 346      * @param int $page Defaults to 0
 347      * @param int $perpage Defaults to 25
 348      * @param int $addedenrollment Defaults to 0
 349      * @return array Array(totalusers => int, users => array)
 350      */
 351     public function get_potential_users($enrolid, $search='', $searchanywhere=false, $page=0, $perpage=25, $addedenrollment=0) {
 352         global $DB;
 353
 354         list($ufields, $params, $wherecondition) = $this->get_basic_search_conditions($search, $searchanywhere);
 355
 356         $fields      = 'SELECT '.$ufields;
 357         $countfields = 'SELECT COUNT(1)';
 358         $sql = " FROM {user} u
 359             LEFT JOIN {user_enrolments} ue ON (ue.userid = u.id AND ue.enrolid = :enrolid)
 360                 WHERE $wherecondition
 361                       AND ue.id IS NULL";
 362         $params['enrolid'] = $enrolid;
 363
 364         return $this->execute_search_queries($search, $fields, $countfields, $sql, $params, $page, $perpage, $addedenrollment);
 365     }
 366
 367     /**
 368      * Searches other users and returns paginated results
 369      *
 370      * @global moodle_database $DB
 371      * @param string $search
 372      * @param bool $searchanywhere
 373      * @param int $page Starting at 0
 374      * @param int $perpage
 375      * @return array
 376      */
 377     public function search_other_users($search='', $searchanywhere=false, $page=0, $perpage=25) {
 378         global $DB, $CFG;
 379
 380         list($ufields, $params, $wherecondition) = $this->get_basic_search_conditions($search, $searchanywhere);
 381
 382         $fields      = 'SELECT ' . $ufields;
 383         $countfields = 'SELECT COUNT(u.id)';
 384         $sql   = " FROM {user} u
 385               LEFT JOIN {role_assignments} ra ON (ra.userid = u.id AND ra.contextid = :contextid)
 386                   WHERE $wherecondition
 387                     AND ra.id IS NULL";
 388         $params['contextid'] = $this->context->id;
 389
 390         return $this->execute_search_queries($search, $fields, $countfields, $sql, $params, $page, $perpage);
 391     }
 392
 393     /**
 394      * Gets an array containing some SQL to user for when selecting, params for
 395      * that SQL, and the filter that was used in constructing the sql.
 396      *
 397      * @global moodle_database $DB
 398      * @return string
 399      */
 400     protected function get_instance_sql() {
 401         global $DB;
 402         if ($this->_instancessql === null) {
 403             $instances = $this->get_enrolment_instances();
 404             $filter = $this->get_enrolment_filter();
 405             if ($filter && array_key_exists($filter, $instances)) {
 406                 $sql = " = :ifilter";
 407                 $params = array('ifilter'=>$filter);
 408             } else {
 409                 $filter = 0;
 410                 if ($instances) {
 411                     list($sql, $params) = $DB->get_in_or_equal(array_keys($this->get_enrolment_instances()), SQL_PARAMS_NAMED);
 412                 } else {
 413                     // no enabled instances, oops, we should probably say something
 414                     $sql = "= :never";
 415                     $params = array('never'=>-1);
 416                 }
 417             }
 418             $this->instancefilter = $filter;
 419             $this->_instancessql = array($sql, $params, $filter);
 420         }
 421         return $this->_instancessql;
 422     }
 423
 424     /**
 425      * Returns all of the enrolment instances for this course.
 426      *
 427      * NOTE: since 2.4 it includes instances of disabled plugins too.
 428      *
 429      * @return array
 430      */
 431     public function get_enrolment_instances() {
 432         if ($this->_instances === null) {
 433             $this->_instances = enrol_get_instances($this->course->id, false);
 434         }
 435         return $this->_instances;
 436     }
 437
 438     /**
 439      * Returns the names for all of the enrolment instances for this course.
 440      *
 441      * NOTE: since 2.4 it includes instances of disabled plugins too.
 442      *
 443      * @return array
 444      */
 445     public function get_enrolment_instance_names() {
 446         if ($this->_inames === null) {
 447             $instances = $this->get_enrolment_instances();
 448             $plugins = $this->get_enrolment_plugins(false);
 449             foreach ($instances as $key=>$instance) {
 450                 if (!isset($plugins[$instance->enrol])) {
 451                     // weird, some broken stuff in plugin
 452                     unset($instances[$key]);
 453                     continue;
 454                 }
 455                 $this->_inames[$key] = $plugins[$instance->enrol]->get_instance_name($instance);
 456             }
 457         }
 458         return $this->_inames;
 459     }
 460
 461     /**
 462      * Gets all of the enrolment plugins that are active for this course.
 463      *
 464      * @param bool $onlyenabled return only enabled enrol plugins
 465      * @return array
 466      */
 467     public function get_enrolment_plugins($onlyenabled = true) {
 468         if ($this->_plugins === null) {
 469             $this->_plugins = enrol_get_plugins(true);
 470         }
 471
 472         if ($onlyenabled) {
 473             return $this->_plugins;
 474         }
 475
 476         if ($this->_allplugins === null) {
 477             // Make sure we have the same objects in _allplugins and _plugins.
 478             $this->_allplugins = $this->_plugins;
 479             foreach (enrol_get_plugins(false) as $name=>$plugin) {
 480                 if (!isset($this->_allplugins[$name])) {
 481                     $this->_allplugins[$name] = $plugin;
 482                 }
 483             }
 484         }
 485
 486         return $this->_allplugins;
 487     }
 488
 489     /**
 490      * Gets all of the roles this course can contain.
 491      *
 492      * @return array
 493      */
 494     public function get_all_roles() {
 495         if ($this->_roles === null) {
 496             $this->_roles = role_fix_names(get_all_roles($this->context), $this->context);
 497         }
 498         return $this->_roles;
 499     }
 500
 501     /**
 502      * Gets all of the assignable roles for this course.
 503      *
 504      * @return array
 505      */
 506     public function get_assignable_roles($otherusers = false) {
 507         if ($this->_assignableroles === null) {
 508             $this->_assignableroles = get_assignable_roles($this->context, ROLENAME_ALIAS, false); // verifies unassign access control too
 509         }
 510
 511         if ($otherusers) {
 512             if (!is_array($this->_assignablerolesothers)) {
 513                 $this->_assignablerolesothers = array();
 514                 list($courseviewroles, $ignored) = get_roles_with_cap_in_context($this->context, 'moodle/course:view');
 515                 foreach ($this->_assignableroles as $roleid=>$role) {
 516                     if (isset($courseviewroles[$roleid])) {
 517                         $this->_assignablerolesothers[$roleid] = $role;
 518                     }
 519                 }
 520             }
 521             return $this->_assignablerolesothers;
 522         } else {
 523             return $this->_assignableroles;
 524         }
 525     }
 526
 527     /**
 528      * Gets all of the groups for this course.
 529      *
 530      * @return array
 531      */
 532     public function get_all_groups() {
 533         if ($this->_groups === null) {
 534             $this->_groups = groups_get_all_groups($this->course->id);
 535             foreach ($this->_groups as $gid=>$group) {
 536                 $this->_groups[$gid]->name = format_string($group->name);
 537             }
 538         }
 539         return $this->_groups;
 540     }
 541
 542     /**
 543      * Unenrols a user from the course given the users ue entry
 544      *
 545      * @global moodle_database $DB
 546      * @param stdClass $ue
 547      * @return bool
 548      */
 549     public function unenrol_user($ue) {
 550         global $DB;
 551         list ($instance, $plugin) = $this->get_user_enrolment_components($ue);
 552         if ($instance && $plugin && $plugin->allow_unenrol_user($instance, $ue) && has_capability("enrol/$instance->enrol:unenrol", $this->context)) {
 553             $plugin->unenrol_user($instance, $ue->userid);
 554             return true;
 555         }
 556         return false;
 557     }
 558
 559     /**
 560      * Given a user enrolment record this method returns the plugin and enrolment
 561      * instance that relate to it.
 562      *
 563      * @param stdClass|int $userenrolment
 564      * @return array array($instance, $plugin)
 565      */
 566     public function get_user_enrolment_components($userenrolment) {
 567         global $DB;
 568         if (is_numeric($userenrolment)) {
 569             $userenrolment = $DB->get_record('user_enrolments', array('id'=>(int)$userenrolment));
 570         }
 571         $instances = $this->get_enrolment_instances();
 572         $plugins = $this->get_enrolment_plugins(false);
 573         if (!$userenrolment || !isset($instances[$userenrolment->enrolid])) {
 574             return array(false, false);
 575         }
 576         $instance = $instances[$userenrolment->enrolid];
 577         $plugin = $plugins[$instance->enrol];
 578         return array($instance, $plugin);
 579     }
 580
 581     /**
 582      * Removes an assigned role from a user.
 583      *
 584      * @global moodle_database $DB
 585      * @param int $userid
 586      * @param int $roleid
 587      * @return bool
 588      */
 589     public function unassign_role_from_user($userid, $roleid) {
 590         global $DB;
 591         // Admins may unassign any role, others only those they could assign.
 592         if (!is_siteadmin() and !array_key_exists($roleid, $this->get_assignable_roles())) {
 593             if (defined('AJAX_SCRIPT')) {
 594                 throw new moodle_exception('invalidrole');
 595             }
 596             return false;
 597         }
 598         $user = $DB->get_record('user', array('id'=>$userid), '*', MUST_EXIST);
 599         $ras = $DB->get_records('role_assignments', array('contextid'=>$this->context->id, 'userid'=>$user->id, 'roleid'=>$roleid));
 600         foreach ($ras as $ra) {
 601             if ($ra->component) {
 602                 if (strpos($ra->component, 'enrol_') !== 0) {
 603                     continue;
 604                 }
 605                 if (!$plugin = enrol_get_plugin(substr($ra->component, 6))) {
 606                     continue;
 607                 }
 608                 if ($plugin->roles_protected()) {
 609                     continue;
 610                 }
 611             }
 612             role_unassign($ra->roleid, $ra->userid, $ra->contextid, $ra->component, $ra->itemid);
 613         }
 614         return true;
 615     }
 616
 617     /**
 618      * Assigns a role to a user.
 619      *
 620      * @param int $roleid
 621      * @param int $userid
 622      * @return int|false
 623      */
 624     public function assign_role_to_user($roleid, $userid) {
 625         require_capability('moodle/role:assign', $this->context);
 626         if (!array_key_exists($roleid, $this->get_assignable_roles())) {
 627             if (defined('AJAX_SCRIPT')) {
 628                 throw new moodle_exception('invalidrole');
 629             }
 630             return false;
 631         }
 632         return role_assign($roleid, $userid, $this->context->id, '', NULL);
 633     }
 634
 635     /**
 636      * Adds a user to a group
 637      *
 638      * @param stdClass $user
 639      * @param int $groupid
 640      * @return bool
 641      */
 642     public function add_user_to_group($user, $groupid) {
 643         require_capability('moodle/course:managegroups', $this->context);
 644         $group = $this->get_group($groupid);
 645         if (!$group) {
 646             return false;
 647         }
 648         return groups_add_member($group->id, $user->id);
 649     }
 650
 651     /**
 652      * Removes a user from a group
 653      *
 654      * @global moodle_database $DB
 655      * @param StdClass $user
 656      * @param int $groupid
 657      * @return bool
 658      */
 659     public function remove_user_from_group($user, $groupid) {
 660         global $DB;
 661         require_capability('moodle/course:managegroups', $this->context);
 662         $group = $this->get_group($groupid);
 663         if (!groups_remove_member_allowed($group, $user)) {
 664             return false;
 665         }
 666         if (!$group) {
 667             return false;
 668         }
 669         return groups_remove_member($group, $user);
 670     }
 671
 672     /**
 673      * Gets the requested group
 674      *
 675      * @param int $groupid
 676      * @return stdClass|int
 677      */
 678     public function get_group($groupid) {
 679         $groups = $this->get_all_groups();
 680         if (!array_key_exists($groupid, $groups)) {
 681             return false;
 682         }
 683         return $groups[$groupid];
 684     }
 685
 686     /**
 687      * Edits an enrolment
 688      *
 689      * @param stdClass $userenrolment
 690      * @param stdClass $data
 691      * @return bool
 692      */
 693     public function edit_enrolment($userenrolment, $data) {
 694         //Only allow editing if the user has the appropriate capability
 695         //Already checked in /enrol/users.php but checking again in case this function is called from elsewhere
 696         list($instance, $plugin) = $this->get_user_enrolment_components($userenrolment);
 697         if ($instance && $plugin && $plugin->allow_manage($instance) && has_capability("enrol/$instance->enrol:manage", $this->context)) {
 698             if (!isset($data->status)) {
 699                 $data->status = $userenrolment->status;
 700             }
 701             $plugin->update_user_enrol($instance, $userenrolment->userid, $data->status, $data->timestart, $data->timeend);
 702             return true;
 703         }
 704         return false;
 705     }
 706
 707     /**
 708      * Returns the current enrolment filter that is being applied by this class
 709      * @return string
 710      */
 711     public function get_enrolment_filter() {
 712         return $this->instancefilter;
 713     }
 714
 715     /**
 716      * Gets the roles assigned to this user that are applicable for this course.
 717      *
 718      * @param int $userid
 719      * @return array
 720      */
 721     public function get_user_roles($userid) {
 722         $roles = array();
 723         $ras = get_user_roles($this->context, $userid, true, 'c.contextlevel DESC, r.sortorder ASC');
 724         $plugins = $this->get_enrolment_plugins(false);
 725         foreach ($ras as $ra) {
 726             if ($ra->contextid != $this->context->id) {
 727                 if (!array_key_exists($ra->roleid, $roles)) {
 728                     $roles[$ra->roleid] = null;
 729                 }
 730                 // higher ras, course always takes precedence
 731                 continue;
 732             }
 733             if (array_key_exists($ra->roleid, $roles) && $roles[$ra->roleid] === false) {
 734                 continue;
 735             }
 736             $changeable = true;
 737             if ($ra->component) {
 738                 $changeable = false;
 739                 if (strpos($ra->component, 'enrol_') === 0) {
 740                     $plugin = substr($ra->component, 6);
 741                     if (isset($plugins[$plugin])) {
 742                         $changeable = !$plugins[$plugin]->roles_protected();
 743                     }
 744                 }
 745             }
 746
 747             $roles[$ra->roleid] = $changeable;
 748         }
 749         return $roles;
 750     }
 751
 752     /**
 753      * Gets the enrolments this user has in the course - including all suspended plugins and instances.
 754      *
 755      * @global moodle_database $DB
 756      * @param int $userid
 757      * @return array
 758      */
 759     public function get_user_enrolments($userid) {
 760         global $DB;
 761         list($instancessql, $params, $filter) = $this->get_instance_sql();
 762         $params['userid'] = $userid;
 763         $userenrolments = $DB->get_records_select('user_enrolments', "enrolid $instancessql AND userid = :userid", $params);
 764         $instances = $this->get_enrolment_instances();
 765         $plugins = $this->get_enrolment_plugins(false);
 766         $inames = $this->get_enrolment_instance_names();
 767         foreach ($userenrolments as &$ue) {
 768             $ue->enrolmentinstance     = $instances[$ue->enrolid];
 769             $ue->enrolmentplugin       = $plugins[$ue->enrolmentinstance->enrol];
 770             $ue->enrolmentinstancename = $inames[$ue->enrolmentinstance->id];
 771         }
 772         return $userenrolments;
 773     }
 774
 775     /**
 776      * Gets the groups this user belongs to
 777      *
 778      * @param int $userid
 779      * @return array
 780      */
 781     public function get_user_groups($userid) {
 782         return groups_get_all_groups($this->course->id, $userid, 0, 'g.id');
 783     }
 784
 785     /**
 786      * Retursn an array of params that would go into the URL to return to this
 787      * exact page.
 788      *
 789      * @return array
 790      */
 791     public function get_url_params() {
 792         $args = array(
 793             'id' => $this->course->id
 794         );
 795         if (!empty($this->instancefilter)) {
 796             $args['ifilter'] = $this->instancefilter;
 797         }
 798         return $args;
 799     }
 800
 801     /**
 802      * Returns the course this object is managing enrolments for
 803      *
 804      * @return stdClass
 805      */
 806     public function get_course() {
 807         return $this->course;
 808     }
 809
 810     /**
 811      * Returns the course context
 812      *
 813      * @return stdClass
 814      */
 815     public function get_context() {
 816         return $this->context;
 817     }
 818
 819     /**
 820      * Gets an array of other users in this course ready for display.
 821      *
 822      * Other users are users who have been assigned or inherited roles within this
 823      * course but have not been enrolled.
 824      *
 825      * @param core_enrol_renderer $renderer
 826      * @param moodle_url $pageurl
 827      * @param string $sort
 828      * @param string $direction ASC | DESC
 829      * @param int $page Starting from 0
 830      * @param int $perpage
 831      * @return array
 832      */
 833     public function get_other_users_for_display(core_enrol_renderer $renderer, moodle_url $pageurl, $sort, $direction, $page, $perpage) {
 834
 835         $userroles = $this->get_other_users($sort, $direction, $page, $perpage);
 836         $roles = $this->get_all_roles();
 837         $plugins = $this->get_enrolment_plugins(false);
 838
 839         $context    = $this->get_context();
 840         $now = time();
 841         $extrafields = get_extra_user_fields($context);
 842
 843         $users = array();
 844         foreach ($userroles as $userrole) {
 845             $contextid = $userrole->contextid;
 846             unset($userrole->contextid); // This would collide with user avatar.
 847             if (!array_key_exists($userrole->id, $users)) {
 848                 $users[$userrole->id] = $this->prepare_user_for_display($userrole, $extrafields, $now);
 849             }
 850             $a = new stdClass;
 851             $a->role = $roles[$userrole->roleid]->localname;
 852             if ($contextid == $this->context->id) {
 853                 $changeable = true;
 854                 if ($userrole->component) {
 855                     $changeable = false;
 856                     if (strpos($userrole->component, 'enrol_') === 0) {
 857                         $plugin = substr($userrole->component, 6);
 858                         if (isset($plugins[$plugin])) {
 859                             $changeable = !$plugin[$plugin]->roles_protected();
 860                         }
 861                     }
 862                 }
 863                 $roletext = get_string('rolefromthiscourse', 'enrol', $a);
 864             } else {
 865                 $changeable = false;
 866                 switch ($userrole->contextlevel) {
 867                     case CONTEXT_COURSE :
 868                         // Meta course
 869                         $roletext = get_string('rolefrommetacourse', 'enrol', $a);
 870                         break;
 871                     case CONTEXT_COURSECAT :
 872                         $roletext = get_string('rolefromcategory', 'enrol', $a);
 873                         break;
 874                     case CONTEXT_SYSTEM:
 875                     default:
 876                         $roletext = get_string('rolefromsystem', 'enrol', $a);
 877                         break;
 878                 }
 879             }
 880             if (!isset($users[$userrole->id]['roles'])) {
 881                 $users[$userrole->id]['roles'] = array();
 882             }
 883             $users[$userrole->id]['roles'][$userrole->roleid] = array(
 884                 'text' => $roletext,
 885                 'unchangeable' => !$changeable
 886             );
 887         }
 888         return $users;
 889     }
 890
 891     /**
 892      * Gets an array of users for display, this includes minimal user information
 893      * as well as minimal information on the users roles, groups, and enrolments.
 894      *
 895      * @param core_enrol_renderer $renderer
 896      * @param moodle_url $pageurl
 897      * @param int $sort
 898      * @param string $direction ASC or DESC
 899      * @param int $page
 900      * @param int $perpage
 901      * @return array
 902      */
 903     public function get_users_for_display(course_enrolment_manager $manager, $sort, $direction, $page, $perpage) {
 904         $pageurl = $manager->get_moodlepage()->url;
 905         $users = $this->get_users($sort, $direction, $page, $perpage);
 906
 907         $now = time();
 908         $straddgroup = get_string('addgroup', 'group');
 909         $strunenrol = get_string('unenrol', 'enrol');
 910         $stredit = get_string('edit');
 911
 912         $allroles   = $this->get_all_roles();
 913         $assignable = $this->get_assignable_roles();
 914         $allgroups  = $this->get_all_groups();
 915         $context    = $this->get_context();
 916         $canmanagegroups = has_capability('moodle/course:managegroups', $context);
 917
 918         $url = new moodle_url($pageurl, $this->get_url_params());
 919         $extrafields = get_extra_user_fields($context);
 920
 921         $enabledplugins = $this->get_enrolment_plugins(true);
 922
 923         $userdetails = array();
 924         foreach ($users as $user) {
 925             $details = $this->prepare_user_for_display($user, $extrafields, $now);
 926
 927             // Roles
 928             $details['roles'] = array();
 929             foreach ($this->get_user_roles($user->id) as $rid=>$rassignable) {
 930                 $unchangeable = !$rassignable;
 931                 if (!is_siteadmin() and !isset($assignable[$rid])) {
 932                     $unchangeable = true;
 933                 }
 934                 $details['roles'][$rid] = array('text'=>$allroles[$rid]->localname, 'unchangeable'=>$unchangeable);
 935             }
 936
 937             // Users
 938             $usergroups = $this->get_user_groups($user->id);
 939             $details['groups'] = array();
 940             foreach($usergroups as $gid=>$unused) {
 941                 $details['groups'][$gid] = $allgroups[$gid]->name;
 942             }
 943
 944             // Enrolments
 945             $details['enrolments'] = array();
 946             foreach ($this->get_user_enrolments($user->id) as $ue) {
 947                 if (!isset($enabledplugins[$ue->enrolmentinstance->enrol])) {
 948                     $details['enrolments'][$ue->id] = array(
 949                         'text' => $ue->enrolmentinstancename,
 950                         'period' => null,
 951                         'dimmed' =>  true,
 952                         'actions' => array()
 953                     );
 954                     continue;
 955                 } else if ($ue->timestart and $ue->timeend) {
 956                     $period = get_string('periodstartend', 'enrol', array('start'=>userdate($ue->timestart), 'end'=>userdate($ue->timeend)));
 957                     $periodoutside = ($ue->timestart && $ue->timeend && $now < $ue->timestart && $now > $ue->timeend);
 958                 } else if ($ue->timestart) {
 959                     $period = get_string('periodstart', 'enrol', userdate($ue->timestart));
 960                     $periodoutside = ($ue->timestart && $now < $ue->timestart);
 961                 } else if ($ue->timeend) {
 962                     $period = get_string('periodend', 'enrol', userdate($ue->timeend));
 963                     $periodoutside = ($ue->timeend && $now > $ue->timeend);
 964                 } else {
 965                     // If there is no start or end show when user was enrolled.
 966                     $period = get_string('periodnone', 'enrol', userdate($ue->timecreated));
 967                     $periodoutside = false;
 968                 }
 969                 $details['enrolments'][$ue->id] = array(
 970                     'text' => $ue->enrolmentinstancename,
 971                     'period' => $period,
 972                     'dimmed' =>  ($periodoutside or $ue->status != ENROL_USER_ACTIVE or $ue->enrolmentinstance->status != ENROL_INSTANCE_ENABLED),
 973                     'actions' => $ue->enrolmentplugin->get_user_enrolment_actions($manager, $ue)
 974                 );
 975             }
 976             $userdetails[$user->id] = $details;
 977         }
 978         return $userdetails;
 979     }
 980
 981     /**
 982      * Prepare a user record for display
 983      *
 984      * This function is called by both {@link get_users_for_display} and {@link get_other_users_for_display} to correctly
 985      * prepare user fields for display
 986      *
 987      * Please note that this function does not check capability for moodle/coures:viewhiddenuserfields
 988      *
 989      * @param object $user The user record
 990      * @param array $extrafields The list of fields as returned from get_extra_user_fields used to determine which
 991      * additional fields may be displayed
 992      * @param int $now The time used for lastaccess calculation
 993      * @return array The fields to be displayed including userid, courseid, picture, firstname, lastseen and any
 994      * additional fields from $extrafields
 995      */
 996     private function prepare_user_for_display($user, $extrafields, $now) {
 997         $details = array(
 998             'userid'    => $user->id,
 999             'courseid'  => $this->get_course()->id,
1000             'picture'   => new user_picture($user),
1001             'firstname' => fullname($user, has_capability('moodle/site:viewfullnames', $this->get_context())),
1002             'lastseen'  => get_string('never'),
1003         );
1004         foreach ($extrafields as $field) {
1005             $details[$field] = $user->{$field};
1006         }
1007
1008         if ($user->lastaccess) {
1009             $details['lastseen'] = format_time($now - $user->lastaccess);
1010         }
1011         return $details;
1012     }
1013
1014     public function get_manual_enrol_buttons() {
1015         $plugins = $this->get_enrolment_plugins(true); // Skip disabled plugins.
1016         $buttons = array();
1017         foreach ($plugins as $plugin) {
1018             $newbutton = $plugin->get_manual_enrol_button($this);
1019             if (is_array($newbutton)) {
1020                 $buttons += $newbutton;
1021             } else if ($newbutton instanceof enrol_user_button) {
1022                 $buttons[] = $newbutton;
1023             }
1024         }
1025         return $buttons;
1026     }
1027
1028     public function has_instance($enrolpluginname) {
1029         // Make sure manual enrolments instance exists
1030         foreach ($this->get_enrolment_instances() as $instance) {
1031             if ($instance->enrol == $enrolpluginname) {
1032                 return true;
1033             }
1034         }
1035         return false;
1036     }
1037
1038     /**
1039      * Returns the enrolment plugin that the course manager was being filtered to.
1040      *
1041      * If no filter was being applied then this function returns false.
1042      *
1043      * @return enrol_plugin
1044      */
1045     public function get_filtered_enrolment_plugin() {
1046         $instances = $this->get_enrolment_instances();
1047         $plugins = $this->get_enrolment_plugins(false);
1048
1049         if (empty($this->instancefilter) || !array_key_exists($this->instancefilter, $instances)) {
1050             return false;
1051         }
1052
1053         $instance = $instances[$this->instancefilter];
1054         return $plugins[$instance->enrol];
1055     }
1056
1057     /**
1058      * Returns and array of users + enrolment details.
1059      *
1060      * Given an array of user id's this function returns and array of user enrolments for those users
1061      * as well as enough user information to display the users name and picture for each enrolment.
1062      *
1063      * @global moodle_database $DB
1064      * @param array $userids
1065      * @return array
1066      */
1067     public function get_users_enrolments(array $userids) {
1068         global $DB;
1069
1070         $instances = $this->get_enrolment_instances();
1071         $plugins = $this->get_enrolment_plugins(false);
1072
1073         if  (!empty($this->instancefilter)) {
1074             $instancesql = ' = :instanceid';
1075             $instanceparams = array('instanceid' => $this->instancefilter);
1076         } else {
1077             list($instancesql, $instanceparams) = $DB->get_in_or_equal(array_keys($instances), SQL_PARAMS_NAMED, 'instanceid0000');
1078         }
1079
1080         $userfields = user_picture::fields('u');
1081         list($idsql, $idparams) = $DB->get_in_or_equal($userids, SQL_PARAMS_NAMED, 'userid0000');
1082
1083         list($sort, $sortparams) = users_order_by_sql('u');
1084
1085         $sql = "SELECT ue.id AS ueid, ue.status, ue.enrolid, ue.userid, ue.timestart, ue.timeend, ue.modifierid, ue.timecreated, ue.timemodified, $userfields
1086                   FROM {user_enrolments} ue
1087              LEFT JOIN {user} u ON u.id = ue.userid
1088                  WHERE ue.enrolid $instancesql AND
1089                        u.id $idsql
1090               ORDER BY $sort";
1091
1092         $rs = $DB->get_recordset_sql($sql, $idparams + $instanceparams + $sortparams);
1093         $users = array();
1094         foreach ($rs as $ue) {
1095             $user = user_picture::unalias($ue);
1096             $ue->id = $ue->ueid;
1097             unset($ue->ueid);
1098             if (!array_key_exists($user->id, $users)) {
1099                 $user->enrolments = array();
1100                 $users[$user->id] = $user;
1101             }
1102             $ue->enrolmentinstance = $instances[$ue->enrolid];
1103             $ue->enrolmentplugin = $plugins[$ue->enrolmentinstance->enrol];
1104             $users[$user->id]->enrolments[$ue->id] = $ue;
1105         }
1106         $rs->close();
1107         return $users;
1108     }
1109 }
1110
1111 /**
1112  * A button that is used to enrol users in a course
1113  *
1114  * @copyright 2010 Sam Hemelryk
1115  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1116  */
1117 class enrol_user_button extends single_button {
1118
1119     /**
1120      * An array containing JS YUI modules required by this button
1121      * @var array
1122      */
1123     protected $jsyuimodules = array();
1124
1125     /**
1126      * An array containing JS initialisation calls required by this button
1127      * @var array
1128      */
1129     protected $jsinitcalls = array();
1130
1131     /**
1132      * An array strings required by JS for this button
1133      * @var array
1134      */
1135     protected $jsstrings = array();
1136
1137     /**
1138      * Initialises the new enrol_user_button
1139      *
1140      * @staticvar int $count The number of enrol user buttons already created
1141      * @param moodle_url $url
1142      * @param string $label The text to display in the button
1143      * @param string $method Either post or get
1144      */
1145     public function __construct(moodle_url $url, $label, $method = 'post') {
1146         static $count = 0;
1147         $count ++;
1148         parent::__construct($url, $label, $method);
1149         $this->class = 'singlebutton enrolusersbutton';
1150         $this->formid = 'enrolusersbutton-'.$count;
1151     }
1152
1153     /**
1154      * Adds a YUI module call that will be added to the page when the button is used.
1155      *
1156      * @param string|array $modules One or more modules to require
1157      * @param string $function The JS function to call
1158      * @param array $arguments An array of arguments to pass to the function
1159      * @param string $galleryversion The YUI gallery version of any modules required
1160      * @param bool $ondomready If true the call is postponed until the DOM is finished loading
1161      */
1162     public function require_yui_module($modules, $function, array $arguments = null, $galleryversion = '2010.04.08-12-35', $ondomready = false) {
1163         $js = new stdClass;
1164         $js->modules = (array)$modules;
1165         $js->function = $function;
1166         $js->arguments = $arguments;
1167         $js->galleryversion = $galleryversion;
1168         $js->ondomready = $ondomready;
1169         $this->jsyuimodules[] = $js;
1170     }
1171
1172     /**
1173      * Adds a JS initialisation call to the page when the button is used.
1174      *
1175      * @param string $function The function to call
1176      * @param array $extraarguments An array of arguments to pass to the function
1177      * @param bool $ondomready If true the call is postponed until the DOM is finished loading
1178      * @param array $module A module definition
1179      */
1180     public function require_js_init_call($function, array $extraarguments = null, $ondomready = false, array $module = null) {
1181         $js = new stdClass;
1182         $js->function = $function;
1183         $js->extraarguments = $extraarguments;
1184         $js->ondomready = $ondomready;
1185         $js->module = $module;
1186         $this->jsinitcalls[] = $js;
1187     }
1188
1189     /**
1190      * Requires strings for JS that will be loaded when the button is used.
1191      *
1192      * @param type $identifiers
1193      * @param string $component
1194      * @param mixed $a
1195      */
1196     public function strings_for_js($identifiers, $component = 'moodle', $a = null) {
1197         $string = new stdClass;
1198         $string->identifiers = (array)$identifiers;
1199         $string->component = $component;
1200         $string->a = $a;
1201         $this->jsstrings[] = $string;
1202     }
1203
1204     /**
1205      * Initialises the JS that is required by this button
1206      *
1207      * @param moodle_page $page
1208      */
1209     public function initialise_js(moodle_page $page) {
1210         foreach ($this->jsyuimodules as $js) {
1211             $page->requires->yui_module($js->modules, $js->function, $js->arguments, $js->galleryversion, $js->ondomready);
1212         }
1213         foreach ($this->jsinitcalls as $js) {
1214             $page->requires->js_init_call($js->function, $js->extraarguments, $js->ondomready, $js->module);
1215         }
1216         foreach ($this->jsstrings as $string) {
1217             $page->requires->strings_for_js($string->identifiers, $string->component, $string->a);
1218         }
1219     }
1220 }
1221
1222 /**
1223  * User enrolment action
1224  *
1225  * This class is used to manage a renderable ue action such as editing an user enrolment or deleting
1226  * a user enrolment.
1227  *
1228  * @copyright  2011 Sam Hemelryk
1229  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1230  */
1231 class user_enrolment_action implements renderable {
1232
1233     /**
1234      * The icon to display for the action
1235      * @var pix_icon
1236      */
1237     protected $icon;
1238
1239     /**
1240      * The title for the action
1241      * @var string
1242      */
1243     protected $title;
1244
1245     /**
1246      * The URL to the action
1247      * @var moodle_url
1248      */
1249     protected $url;
1250
1251     /**
1252      * An array of HTML attributes
1253      * @var array
1254      */
1255     protected $attributes = array();
1256
1257     /**
1258      * Constructor
1259      * @param pix_icon $icon
1260      * @param string $title
1261      * @param moodle_url $url
1262      * @param array $attributes
1263      */
1264     public function __construct(pix_icon $icon, $title, $url, array $attributes = null) {
1265         $this->icon = $icon;
1266         $this->title = $title;
1267         $this->url = new moodle_url($url);
1268         if (!empty($attributes)) {
1269             $this->attributes = $attributes;
1270         }
1271         $this->attributes['title'] = $title;
1272     }
1273
1274     /**
1275      * Returns the icon for this action
1276      * @return pix_icon
1277      */
1278     public function get_icon() {
1279         return $this->icon;
1280     }
1281
1282     /**
1283      * Returns the title for this action
1284      * @return string
1285      */
1286     public function get_title() {
1287         return $this->title;
1288     }
1289
1290     /**
1291      * Returns the URL for this action
1292      * @return moodle_url
1293      */
1294     public function get_url() {
1295         return $this->url;
1296     }
1297
1298     /**
1299      * Returns the attributes to use for this action
1300      * @return array
1301      */
1302     public function get_attributes() {
1303         return $this->attributes;
1304     }
1305 }
1306
1307 class enrol_ajax_exception extends moodle_exception {
1308     /**
1309      * Constructor
1310      * @param string $errorcode The name of the string from error.php to print
1311      * @param string $module name of module
1312      * @param string $link The url where the user will be prompted to continue. If no url is provided the user will be directed to the site index page.
1313      * @param object $a Extra words and phrases that might be required in the error string
1314      * @param string $debuginfo optional debugging information
1315      */
1316     public function __construct($errorcode, $link = '', $a = NULL, $debuginfo = null) {
1317         parent::__construct($errorcode, 'enrol', $link, $a, $debuginfo);
1318     }
1319 }
1320
1321 /**
1322  * This class is used to manage a bulk operations for enrolment plugins.
1323  *
1324  * @copyright 2011 Sam Hemelryk
1325  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1326  */
1327 abstract class enrol_bulk_enrolment_operation {
1328
1329     /**
1330      * The course enrolment manager
1331      * @var course_enrolment_manager
1332      */
1333     protected $manager;
1334
1335     /**
1336      * The enrolment plugin to which this operation belongs
1337      * @var enrol_plugin
1338      */
1339     protected $plugin;
1340
1341     /**
1342      * Contructor
1343      * @param course_enrolment_manager $manager
1344      * @param stdClass $plugin
1345      */
1346     public function __construct(course_enrolment_manager $manager, enrol_plugin $plugin = null) {
1347         $this->manager = $manager;
1348         $this->plugin = $plugin;
1349     }
1350
1351     /**
1352      * Returns a moodleform used for this operation, or false if no form is required and the action
1353      * should be immediatly processed.
1354      *
1355      * @param moodle_url|string $defaultaction
1356      * @param mixed $defaultcustomdata
1357      * @return enrol_bulk_enrolment_change_form|moodleform|false
1358      */
1359     public function get_form($defaultaction = null, $defaultcustomdata = null) {
1360         return false;
1361     }
1362
1363     /**
1364      * Returns the title to use for this bulk operation
1365      *
1366      * @return string
1367      */
1368     abstract public function get_title();
1369
1370     /**
1371      * Returns the identifier for this bulk operation.
1372      * This should be the same identifier used by the plugins function when returning
1373      * all of its bulk operations.
1374      *
1375      * @return string
1376      */
1377     abstract public function get_identifier();
1378
1379     /**
1380      * Processes the bulk operation on the given users
1381      *
1382      * @param course_enrolment_manager $manager
1383      * @param array $users
1384      * @param stdClass $properties
1385      */
1386     abstract public function process(course_enrolment_manager $manager, array $users, stdClass $properties);
1387 }