group/lib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 /**
  19  * Extra library for groups and groupings.
  20  *
  21  * @copyright 2006 The Open University, J.White AT open.ac.uk, Petr Skoda (skodak)
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  * @package   core_group
  24  */
  25
  26 /*
  27  * INTERNAL FUNCTIONS - to be used by moodle core only
  28  * require_once $CFG->dirroot.'/group/lib.php' must be used
  29  */
  30
  31 /**
  32  * Adds a specified user to a group
  33  *
  34  * @param mixed $grouporid  The group id or group object
  35  * @param mixed $userorid   The user id or user object
  36  * @param string $component Optional component name e.g. 'enrol_imsenterprise'
  37  * @param int $itemid Optional itemid associated with component
  38  * @return bool True if user added successfully or the user is already a
  39  * member of the group, false otherwise.
  40  */
  41 function groups_add_member($grouporid, $userorid, $component=null, $itemid=0) {
  42     global $DB;
  43
  44     if (is_object($userorid)) {
  45         $userid = $userorid->id;
  46         $user   = $userorid;
  47         if (!isset($user->deleted)) {
  48             $user = $DB->get_record('user', array('id'=>$userid), '*', MUST_EXIST);
  49         }
  50     } else {
  51         $userid = $userorid;
  52         $user = $DB->get_record('user', array('id'=>$userid), '*', MUST_EXIST);
  53     }
  54
  55     if ($user->deleted) {
  56         return false;
  57     }
  58
  59     if (is_object($grouporid)) {
  60         $groupid = $grouporid->id;
  61         $group   = $grouporid;
  62     } else {
  63         $groupid = $grouporid;
  64         $group = $DB->get_record('groups', array('id'=>$groupid), '*', MUST_EXIST);
  65     }
  66
  67     // Check if the user a participant of the group course.
  68     $context = context_course::instance($group->courseid);
  69     if (!is_enrolled($context, $userid)) {
  70         return false;
  71     }
  72
  73     if (groups_is_member($groupid, $userid)) {
  74         return true;
  75     }
  76
  77     $member = new stdClass();
  78     $member->groupid   = $groupid;
  79     $member->userid    = $userid;
  80     $member->timeadded = time();
  81     $member->component = '';
  82     $member->itemid = 0;
  83
  84     // Check the component exists if specified
  85     if (!empty($component)) {
  86         $dir = core_component::get_component_directory($component);
  87         if ($dir && is_dir($dir)) {
  88             // Component exists and can be used
  89             $member->component = $component;
  90             $member->itemid = $itemid;
  91         } else {
  92             throw new coding_exception('Invalid call to groups_add_member(). An invalid component was specified');
  93         }
  94     }
  95
  96     if ($itemid !== 0 && empty($member->component)) {
  97         // An itemid can only be specified if a valid component was found
  98         throw new coding_exception('Invalid call to groups_add_member(). A component must be specified if an itemid is given');
  99     }
 100
 101     $DB->insert_record('groups_members', $member);
 102
 103     // Update group info, and group object.
 104     $DB->set_field('groups', 'timemodified', $member->timeadded, array('id'=>$groupid));
 105     $group->timemodified = $member->timeadded;
 106
 107     // Trigger group event.
 108     $params = array(
 109         'context' => $context,
 110         'objectid' => $groupid,
 111         'relateduserid' => $userid,
 112         'other' => array(
 113             'component' => $member->component,
 114             'itemid' => $member->itemid
 115         )
 116     );
 117     $event = \core\event\group_member_added::create($params);
 118     $event->add_record_snapshot('groups', $group);
 119     $event->trigger();
 120
 121     return true;
 122 }
 123
 124 /**
 125  * Checks whether the current user is permitted (using the normal UI) to
 126  * remove a specific group member, assuming that they have access to remove
 127  * group members in general.
 128  *
 129  * For automatically-created group member entries, this checks with the
 130  * relevant plugin to see whether it is permitted. The default, if the plugin
 131  * doesn't provide a function, is true.
 132  *
 133  * For other entries (and any which have already been deleted/don't exist) it
 134  * just returns true.
 135  *
 136  * @param mixed $grouporid The group id or group object
 137  * @param mixed $userorid The user id or user object
 138  * @return bool True if permitted, false otherwise
 139  */
 140 function groups_remove_member_allowed($grouporid, $userorid) {
 141     global $DB;
 142
 143     if (is_object($userorid)) {
 144         $userid = $userorid->id;
 145     } else {
 146         $userid = $userorid;
 147     }
 148     if (is_object($grouporid)) {
 149         $groupid = $grouporid->id;
 150     } else {
 151         $groupid = $grouporid;
 152     }
 153
 154     // Get entry
 155     if (!($entry = $DB->get_record('groups_members',
 156             array('groupid' => $groupid, 'userid' => $userid), '*', IGNORE_MISSING))) {
 157         // If the entry does not exist, they are allowed to remove it (this
 158         // is consistent with groups_remove_member below).
 159         return true;
 160     }
 161
 162     // If the entry does not have a component value, they can remove it
 163     if (empty($entry->component)) {
 164         return true;
 165     }
 166
 167     // It has a component value, so we need to call a plugin function (if it
 168     // exists); the default is to allow removal
 169     return component_callback($entry->component, 'allow_group_member_remove',
 170             array($entry->itemid, $entry->groupid, $entry->userid), true);
 171 }
 172
 173 /**
 174  * Deletes the link between the specified user and group.
 175  *
 176  * @param mixed $grouporid  The group id or group object
 177  * @param mixed $userorid   The user id or user object
 178  * @return bool True if deletion was successful, false otherwise
 179  */
 180 function groups_remove_member($grouporid, $userorid) {
 181     global $DB;
 182
 183     if (is_object($userorid)) {
 184         $userid = $userorid->id;
 185     } else {
 186         $userid = $userorid;
 187     }
 188
 189     if (is_object($grouporid)) {
 190         $groupid = $grouporid->id;
 191         $group   = $grouporid;
 192     } else {
 193         $groupid = $grouporid;
 194         $group = $DB->get_record('groups', array('id'=>$groupid), '*', MUST_EXIST);
 195     }
 196
 197     if (!groups_is_member($groupid, $userid)) {
 198         return true;
 199     }
 200
 201     $DB->delete_records('groups_members', array('groupid'=>$groupid, 'userid'=>$userid));
 202
 203     // Update group info.
 204     $time = time();
 205     $DB->set_field('groups', 'timemodified', $time, array('id' => $groupid));
 206     $group->timemodified = $time;
 207
 208     // Trigger group event.
 209     $params = array(
 210         'context' => context_course::instance($group->courseid),
 211         'objectid' => $groupid,
 212         'relateduserid' => $userid
 213     );
 214     $event = \core\event\group_member_removed::create($params);
 215     $event->add_record_snapshot('groups', $group);
 216     $event->trigger();
 217
 218     return true;
 219 }
 220
 221 /**
 222  * Add a new group
 223  *
 224  * @param stdClass $data group properties
 225  * @param stdClass $editform
 226  * @param array $editoroptions
 227  * @return id of group or false if error
 228  */
 229 function groups_create_group($data, $editform = false, $editoroptions = false) {
 230     global $CFG, $DB;
 231
 232     //check that courseid exists
 233     $course = $DB->get_record('course', array('id' => $data->courseid), '*', MUST_EXIST);
 234     $context = context_course::instance($course->id);
 235
 236     $data->timecreated  = time();
 237     $data->timemodified = $data->timecreated;
 238     $data->name         = trim($data->name);
 239     if (isset($data->idnumber)) {
 240         $data->idnumber = trim($data->idnumber);
 241         if (groups_get_group_by_idnumber($course->id, $data->idnumber)) {
 242             throw new moodle_exception('idnumbertaken');
 243         }
 244     }
 245
 246     if ($editform and $editoroptions) {
 247         $data->description = $data->description_editor['text'];
 248         $data->descriptionformat = $data->description_editor['format'];
 249     }
 250
 251     $data->id = $DB->insert_record('groups', $data);
 252
 253     if ($editform and $editoroptions) {
 254         // Update description from editor with fixed files
 255         $data = file_postupdate_standard_editor($data, 'description', $editoroptions, $context, 'group', 'description', $data->id);
 256         $upd = new stdClass();
 257         $upd->id                = $data->id;
 258         $upd->description       = $data->description;
 259         $upd->descriptionformat = $data->descriptionformat;
 260         $DB->update_record('groups', $upd);
 261     }
 262
 263     $group = $DB->get_record('groups', array('id'=>$data->id));
 264
 265     if ($editform) {
 266         groups_update_group_icon($group, $data, $editform);
 267     }
 268
 269     // Invalidate the grouping cache for the course
 270     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($course->id));
 271
 272     // Trigger group event.
 273     $params = array(
 274         'context' => $context,
 275         'objectid' => $group->id
 276     );
 277     $event = \core\event\group_created::create($params);
 278     $event->add_record_snapshot('groups', $group);
 279     $event->trigger();
 280
 281     return $group->id;
 282 }
 283
 284 /**
 285  * Add a new grouping
 286  *
 287  * @param stdClass $data grouping properties
 288  * @param array $editoroptions
 289  * @return id of grouping or false if error
 290  */
 291 function groups_create_grouping($data, $editoroptions=null) {
 292     global $DB;
 293
 294     $data->timecreated  = time();
 295     $data->timemodified = $data->timecreated;
 296     $data->name         = trim($data->name);
 297     if (isset($data->idnumber)) {
 298         $data->idnumber = trim($data->idnumber);
 299         if (groups_get_grouping_by_idnumber($data->courseid, $data->idnumber)) {
 300             throw new moodle_exception('idnumbertaken');
 301         }
 302     }
 303
 304     if ($editoroptions !== null) {
 305         $data->description = $data->description_editor['text'];
 306         $data->descriptionformat = $data->description_editor['format'];
 307     }
 308
 309     $id = $DB->insert_record('groupings', $data);
 310     $data->id = $id;
 311
 312     if ($editoroptions !== null) {
 313         $description = new stdClass;
 314         $description->id = $data->id;
 315         $description->description_editor = $data->description_editor;
 316         $description = file_postupdate_standard_editor($description, 'description', $editoroptions, $editoroptions['context'], 'grouping', 'description', $description->id);
 317         $DB->update_record('groupings', $description);
 318     }
 319
 320     // Invalidate the grouping cache for the course
 321     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($data->courseid));
 322
 323     // Trigger group event.
 324     $params = array(
 325         'context' => context_course::instance($data->courseid),
 326         'objectid' => $id
 327     );
 328     $event = \core\event\grouping_created::create($params);
 329     $event->trigger();
 330
 331     return $id;
 332 }
 333
 334 /**
 335  * Update the group icon from form data
 336  *
 337  * @param stdClass $group group information
 338  * @param stdClass $data
 339  * @param stdClass $editform
 340  */
 341 function groups_update_group_icon($group, $data, $editform) {
 342     global $CFG, $DB;
 343     require_once("$CFG->libdir/gdlib.php");
 344
 345     $fs = get_file_storage();
 346     $context = context_course::instance($group->courseid, MUST_EXIST);
 347
 348     //TODO: it would make sense to allow picture deleting too (skodak)
 349     if ($iconfile = $editform->save_temp_file('imagefile')) {
 350         if ($rev = process_new_icon($context, 'group', 'icon', $group->id, $iconfile)) {
 351             $DB->set_field('groups', 'picture', $rev, array('id'=>$group->id));
 352             $group->picture = $rev;
 353         } else {
 354             $fs->delete_area_files($context->id, 'group', 'icon', $group->id);
 355             $DB->set_field('groups', 'picture', 0, array('id'=>$group->id));
 356             $group->picture = 0;
 357         }
 358         @unlink($iconfile);
 359         // Invalidate the group data as we've updated the group record.
 360         cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($group->courseid));
 361     }
 362 }
 363
 364 /**
 365  * Update group
 366  *
 367  * @param stdClass $data group properties (with magic quotes)
 368  * @param stdClass $editform
 369  * @param array $editoroptions
 370  * @return bool true or exception
 371  */
 372 function groups_update_group($data, $editform = false, $editoroptions = false) {
 373     global $CFG, $DB;
 374
 375     $context = context_course::instance($data->courseid);
 376
 377     $data->timemodified = time();
 378     if (isset($data->name)) {
 379         $data->name = trim($data->name);
 380     }
 381     if (isset($data->idnumber)) {
 382         $data->idnumber = trim($data->idnumber);
 383         if (($existing = groups_get_group_by_idnumber($data->courseid, $data->idnumber)) && $existing->id != $data->id) {
 384             throw new moodle_exception('idnumbertaken');
 385         }
 386     }
 387
 388     if ($editform and $editoroptions) {
 389         $data = file_postupdate_standard_editor($data, 'description', $editoroptions, $context, 'group', 'description', $data->id);
 390     }
 391
 392     $DB->update_record('groups', $data);
 393
 394     // Invalidate the group data.
 395     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($data->courseid));
 396
 397     $group = $DB->get_record('groups', array('id'=>$data->id));
 398
 399     if ($editform) {
 400         groups_update_group_icon($group, $data, $editform);
 401     }
 402
 403     // Trigger group event.
 404     $params = array(
 405         'context' => $context,
 406         'objectid' => $group->id
 407     );
 408     $event = \core\event\group_updated::create($params);
 409     $event->add_record_snapshot('groups', $group);
 410     $event->trigger();
 411
 412     return true;
 413 }
 414
 415 /**
 416  * Update grouping
 417  *
 418  * @param stdClass $data grouping properties (with magic quotes)
 419  * @param array $editoroptions
 420  * @return bool true or exception
 421  */
 422 function groups_update_grouping($data, $editoroptions=null) {
 423     global $DB;
 424     $data->timemodified = time();
 425     if (isset($data->name)) {
 426         $data->name = trim($data->name);
 427     }
 428     if (isset($data->idnumber)) {
 429         $data->idnumber = trim($data->idnumber);
 430         if (($existing = groups_get_grouping_by_idnumber($data->courseid, $data->idnumber)) && $existing->id != $data->id) {
 431             throw new moodle_exception('idnumbertaken');
 432         }
 433     }
 434     if ($editoroptions !== null) {
 435         $data = file_postupdate_standard_editor($data, 'description', $editoroptions, $editoroptions['context'], 'grouping', 'description', $data->id);
 436     }
 437     $DB->update_record('groupings', $data);
 438
 439     // Invalidate the group data.
 440     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($data->courseid));
 441
 442     // Trigger group event.
 443     $params = array(
 444         'context' => context_course::instance($data->courseid),
 445         'objectid' => $data->id
 446     );
 447     $event = \core\event\grouping_updated::create($params);
 448     $event->trigger();
 449
 450     return true;
 451 }
 452
 453 /**
 454  * Delete a group best effort, first removing members and links with courses and groupings.
 455  * Removes group avatar too.
 456  *
 457  * @param mixed $grouporid The id of group to delete or full group object
 458  * @return bool True if deletion was successful, false otherwise
 459  */
 460 function groups_delete_group($grouporid) {
 461     global $CFG, $DB;
 462     require_once("$CFG->libdir/gdlib.php");
 463
 464     if (is_object($grouporid)) {
 465         $groupid = $grouporid->id;
 466         $group   = $grouporid;
 467     } else {
 468         $groupid = $grouporid;
 469         if (!$group = $DB->get_record('groups', array('id'=>$groupid))) {
 470             //silently ignore attempts to delete missing already deleted groups ;-)
 471             return true;
 472         }
 473     }
 474
 475     // delete group calendar events
 476     $DB->delete_records('event', array('groupid'=>$groupid));
 477     //first delete usage in groupings_groups
 478     $DB->delete_records('groupings_groups', array('groupid'=>$groupid));
 479     //delete members
 480     $DB->delete_records('groups_members', array('groupid'=>$groupid));
 481     //group itself last
 482     $DB->delete_records('groups', array('id'=>$groupid));
 483
 484     // Delete all files associated with this group
 485     $context = context_course::instance($group->courseid);
 486     $fs = get_file_storage();
 487     $fs->delete_area_files($context->id, 'group', 'description', $groupid);
 488     $fs->delete_area_files($context->id, 'group', 'icon', $groupid);
 489
 490     // Invalidate the grouping cache for the course
 491     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($group->courseid));
 492
 493     // Trigger group event.
 494     $params = array(
 495         'context' => $context,
 496         'objectid' => $groupid
 497     );
 498     $event = \core\event\group_deleted::create($params);
 499     $event->add_record_snapshot('groups', $group);
 500     $event->trigger();
 501
 502     return true;
 503 }
 504
 505 /**
 506  * Delete grouping
 507  *
 508  * @param int $groupingorid
 509  * @return bool success
 510  */
 511 function groups_delete_grouping($groupingorid) {
 512     global $DB;
 513
 514     if (is_object($groupingorid)) {
 515         $groupingid = $groupingorid->id;
 516         $grouping   = $groupingorid;
 517     } else {
 518         $groupingid = $groupingorid;
 519         if (!$grouping = $DB->get_record('groupings', array('id'=>$groupingorid))) {
 520             //silently ignore attempts to delete missing already deleted groupings ;-)
 521             return true;
 522         }
 523     }
 524
 525     //first delete usage in groupings_groups
 526     $DB->delete_records('groupings_groups', array('groupingid'=>$groupingid));
 527     // remove the default groupingid from course
 528     $DB->set_field('course', 'defaultgroupingid', 0, array('defaultgroupingid'=>$groupingid));
 529     // remove the groupingid from all course modules
 530     $DB->set_field('course_modules', 'groupingid', 0, array('groupingid'=>$groupingid));
 531     //group itself last
 532     $DB->delete_records('groupings', array('id'=>$groupingid));
 533
 534     $context = context_course::instance($grouping->courseid);
 535     $fs = get_file_storage();
 536     $files = $fs->get_area_files($context->id, 'grouping', 'description', $groupingid);
 537     foreach ($files as $file) {
 538         $file->delete();
 539     }
 540
 541     // Invalidate the grouping cache for the course
 542     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($grouping->courseid));
 543
 544     // Trigger group event.
 545     $params = array(
 546         'context' => $context,
 547         'objectid' => $groupingid
 548     );
 549     $event = \core\event\grouping_deleted::create($params);
 550     $event->add_record_snapshot('groupings', $grouping);
 551     $event->trigger();
 552
 553     return true;
 554 }
 555
 556 /**
 557  * Remove all users (or one user) from all groups in course
 558  *
 559  * @param int $courseid
 560  * @param int $userid 0 means all users
 561  * @param bool $showfeedback
 562  * @return bool success
 563  */
 564 function groups_delete_group_members($courseid, $userid=0, $showfeedback=false) {
 565     global $DB, $OUTPUT;
 566
 567     if (is_bool($userid)) {
 568         debugging('Incorrect userid function parameter');
 569         return false;
 570     }
 571
 572     // Select * so that the function groups_remove_member() gets the whole record.
 573     $groups = $DB->get_recordset('groups', array('courseid' => $courseid));
 574     foreach ($groups as $group) {
 575         if ($userid) {
 576             $userids = array($userid);
 577         } else {
 578             $userids = $DB->get_fieldset_select('groups_members', 'userid', 'groupid = :groupid', array('groupid' => $group->id));
 579         }
 580
 581         foreach ($userids as $id) {
 582             groups_remove_member($group, $id);
 583         }
 584     }
 585
 586     // TODO MDL-41312 Remove events_trigger_legacy('groups_members_removed').
 587     // This event is kept here for backwards compatibility, because it cannot be
 588     // translated to a new event as it is wrong.
 589     $eventdata = new stdClass();
 590     $eventdata->courseid = $courseid;
 591     $eventdata->userid   = $userid;
 592     events_trigger_legacy('groups_members_removed', $eventdata);
 593
 594     if ($showfeedback) {
 595         echo $OUTPUT->notification(get_string('deleted').' - '.get_string('groupmembers', 'group'), 'notifysuccess');
 596     }
 597
 598     return true;
 599 }
 600
 601 /**
 602  * Remove all groups from all groupings in course
 603  *
 604  * @param int $courseid
 605  * @param bool $showfeedback
 606  * @return bool success
 607  */
 608 function groups_delete_groupings_groups($courseid, $showfeedback=false) {
 609     global $DB, $OUTPUT;
 610
 611     $groupssql = "SELECT id FROM {groups} g WHERE g.courseid = ?";
 612     $results = $DB->get_recordset_select('groupings_groups', "groupid IN ($groupssql)",
 613         array($courseid), '', 'groupid, groupingid');
 614
 615     foreach ($results as $result) {
 616         groups_unassign_grouping($result->groupingid, $result->groupid, false);
 617     }
 618
 619     // Invalidate the grouping cache for the course
 620     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 621
 622     // TODO MDL-41312 Remove events_trigger_legacy('groups_groupings_groups_removed').
 623     // This event is kept here for backwards compatibility, because it cannot be
 624     // translated to a new event as it is wrong.
 625     events_trigger_legacy('groups_groupings_groups_removed', $courseid);
 626
 627     // no need to show any feedback here - we delete usually first groupings and then groups
 628
 629     return true;
 630 }
 631
 632 /**
 633  * Delete all groups from course
 634  *
 635  * @param int $courseid
 636  * @param bool $showfeedback
 637  * @return bool success
 638  */
 639 function groups_delete_groups($courseid, $showfeedback=false) {
 640     global $CFG, $DB, $OUTPUT;
 641
 642     $groups = $DB->get_recordset('groups', array('courseid' => $courseid));
 643     foreach ($groups as $group) {
 644         groups_delete_group($group);
 645     }
 646
 647     // Invalidate the grouping cache for the course
 648     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 649
 650     // TODO MDL-41312 Remove events_trigger_legacy('groups_groups_deleted').
 651     // This event is kept here for backwards compatibility, because it cannot be
 652     // translated to a new event as it is wrong.
 653     events_trigger_legacy('groups_groups_deleted', $courseid);
 654
 655     if ($showfeedback) {
 656         echo $OUTPUT->notification(get_string('deleted').' - '.get_string('groups', 'group'), 'notifysuccess');
 657     }
 658
 659     return true;
 660 }
 661
 662 /**
 663  * Delete all groupings from course
 664  *
 665  * @param int $courseid
 666  * @param bool $showfeedback
 667  * @return bool success
 668  */
 669 function groups_delete_groupings($courseid, $showfeedback=false) {
 670     global $DB, $OUTPUT;
 671
 672     $groupings = $DB->get_recordset_select('groupings', 'courseid = ?', array($courseid));
 673     foreach ($groupings as $grouping) {
 674         groups_delete_grouping($grouping);
 675     }
 676
 677     // Invalidate the grouping cache for the course.
 678     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 679
 680     // TODO MDL-41312 Remove events_trigger_legacy('groups_groupings_deleted').
 681     // This event is kept here for backwards compatibility, because it cannot be
 682     // translated to a new event as it is wrong.
 683     events_trigger_legacy('groups_groupings_deleted', $courseid);
 684
 685     if ($showfeedback) {
 686         echo $OUTPUT->notification(get_string('deleted').' - '.get_string('groupings', 'group'), 'notifysuccess');
 687     }
 688
 689     return true;
 690 }
 691
 692 /* =================================== */
 693 /* various functions used by groups UI */
 694 /* =================================== */
 695
 696 /**
 697  * Obtains a list of the possible roles that group members might come from,
 698  * on a course. Generally this includes only profile roles.
 699  *
 700  * @param context $context Context of course
 701  * @return Array of role ID integers, or false if error/none.
 702  */
 703 function groups_get_possible_roles($context) {
 704     $roles = get_profile_roles($context);
 705     return array_keys($roles);
 706 }
 707
 708
 709 /**
 710  * Gets potential group members for grouping
 711  *
 712  * @param int $courseid The id of the course
 713  * @param int $roleid The role to select users from
 714  * @param mixed $source restrict to cohort, grouping or group id
 715  * @param string $orderby The column to sort users by
 716  * @param int $notingroup restrict to users not in existing groups
 717  * @return array An array of the users
 718  */
 719 function groups_get_potential_members($courseid, $roleid = null, $source = null,
 720                                       $orderby = 'lastname ASC, firstname ASC',
 721                                       $notingroup = null) {
 722     global $DB;
 723
 724     $context = context_course::instance($courseid);
 725
 726     list($esql, $params) = get_enrolled_sql($context);
 727
 728     $notingroupsql = "";
 729     if ($notingroup) {
 730         // We want to eliminate users that are already associated with a course group.
 731         $notingroupsql = "u.id NOT IN (SELECT userid
 732                                          FROM {groups_members}
 733                                         WHERE groupid IN (SELECT id
 734                                                             FROM {groups}
 735                                                            WHERE courseid = :courseid))";
 736         $params['courseid'] = $courseid;
 737     }
 738
 739     if ($roleid) {
 740         // We are looking for all users with this role assigned in this context or higher.
 741         list($relatedctxsql, $relatedctxparams) = $DB->get_in_or_equal($context->get_parent_context_ids(true),
 742                                                                        SQL_PARAMS_NAMED,
 743                                                                        'relatedctx');
 744
 745         $params = array_merge($params, $relatedctxparams, array('roleid' => $roleid));
 746         $where = "WHERE u.id IN (SELECT userid
 747                                    FROM {role_assignments}
 748                                   WHERE roleid = :roleid AND contextid $relatedctxsql)";
 749         $where .= $notingroup ? "AND $notingroupsql" : "";
 750     } else if ($notingroup) {
 751         $where = "WHERE $notingroupsql";
 752     } else {
 753         $where = "";
 754     }
 755
 756     $sourcejoin = "";
 757     if (is_int($source)) {
 758         $sourcejoin .= "JOIN {cohort_members} cm ON (cm.userid = u.id AND cm.cohortid = :cohortid) ";
 759         $params['cohortid'] = $source;
 760     } else {
 761         // Auto-create groups from an existing cohort membership.
 762         if (isset($source['cohortid'])) {
 763             $sourcejoin .= "JOIN {cohort_members} cm ON (cm.userid = u.id AND cm.cohortid = :cohortid) ";
 764             $params['cohortid'] = $source['cohortid'];
 765         }
 766         // Auto-create groups from an existing group membership.
 767         if (isset($source['groupid'])) {
 768             $sourcejoin .= "JOIN {groups_members} gp ON (gp.userid = u.id AND gp.groupid = :groupid) ";
 769             $params['groupid'] = $source['groupid'];
 770         }
 771         // Auto-create groups from an existing grouping membership.
 772         if (isset($source['groupingid'])) {
 773             $sourcejoin .= "JOIN {groupings_groups} gg ON gg.groupingid = :groupingid ";
 774             $sourcejoin .= "JOIN {groups_members} gm ON (gm.userid = u.id AND gm.groupid = gg.groupid) ";
 775             $params['groupingid'] = $source['groupingid'];
 776         }
 777     }
 778
 779     $allusernamefields = get_all_user_name_fields(true, 'u');
 780     $sql = "SELECT DISTINCT u.id, u.username, $allusernamefields, u.idnumber
 781               FROM {user} u
 782               JOIN ($esql) e ON e.id = u.id
 783        $sourcejoin
 784             $where
 785           ORDER BY $orderby";
 786
 787     return $DB->get_records_sql($sql, $params);
 788
 789 }
 790
 791 /**
 792  * Parse a group name for characters to replace
 793  *
 794  * @param string $format The format a group name will follow
 795  * @param int $groupnumber The number of the group to be used in the parsed format string
 796  * @return string the parsed format string
 797  */
 798 function groups_parse_name($format, $groupnumber) {
 799     if (strstr($format, '@') !== false) { // Convert $groupnumber to a character series
 800         $letter = 'A';
 801         for($i=0; $i<$groupnumber; $i++) {
 802             $letter++;
 803         }
 804         $str = str_replace('@', $letter, $format);
 805     } else {
 806         $str = str_replace('#', $groupnumber+1, $format);
 807     }
 808     return($str);
 809 }
 810
 811 /**
 812  * Assigns group into grouping
 813  *
 814  * @param int groupingid
 815  * @param int groupid
 816  * @param int $timeadded  The time the group was added to the grouping.
 817  * @param bool $invalidatecache If set to true the course group cache will be invalidated as well.
 818  * @return bool true or exception
 819  */
 820 function groups_assign_grouping($groupingid, $groupid, $timeadded = null, $invalidatecache = true) {
 821     global $DB;
 822
 823     if ($DB->record_exists('groupings_groups', array('groupingid'=>$groupingid, 'groupid'=>$groupid))) {
 824         return true;
 825     }
 826     $assign = new stdClass();
 827     $assign->groupingid = $groupingid;
 828     $assign->groupid    = $groupid;
 829     if ($timeadded != null) {
 830         $assign->timeadded = (integer)$timeadded;
 831     } else {
 832         $assign->timeadded = time();
 833     }
 834     $DB->insert_record('groupings_groups', $assign);
 835
 836     if ($invalidatecache) {
 837         // Invalidate the grouping cache for the course
 838         $courseid = $DB->get_field('groupings', 'courseid', array('id' => $groupingid));
 839         cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 840     }
 841
 842     return true;
 843 }
 844
 845 /**
 846  * Unassigns group from grouping
 847  *
 848  * @param int groupingid
 849  * @param int groupid
 850  * @param bool $invalidatecache If set to true the course group cache will be invalidated as well.
 851  * @return bool success
 852  */
 853 function groups_unassign_grouping($groupingid, $groupid, $invalidatecache = true) {
 854     global $DB;
 855     $DB->delete_records('groupings_groups', array('groupingid'=>$groupingid, 'groupid'=>$groupid));
 856
 857     if ($invalidatecache) {
 858         // Invalidate the grouping cache for the course
 859         $courseid = $DB->get_field('groupings', 'courseid', array('id' => $groupingid));
 860         cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 861     }
 862
 863     return true;
 864 }
 865
 866 /**
 867  * Lists users in a group based on their role on the course.
 868  * Returns false if there's an error or there are no users in the group.
 869  * Otherwise returns an array of role ID => role data, where role data includes:
 870  * (role) $id, $shortname, $name
 871  * $users: array of objects for each user which include the specified fields
 872  * Users who do not have a role are stored in the returned array with key '-'
 873  * and pseudo-role details (including a name, 'No role'). Users with multiple
 874  * roles, same deal with key '*' and name 'Multiple roles'. You can find out
 875  * which roles each has by looking in the $roles array of the user object.
 876  *
 877  * @param int $groupid
 878  * @param int $courseid Course ID (should match the group's course)
 879  * @param string $fields List of fields from user table prefixed with u, default 'u.*'
 880  * @param string $sort SQL ORDER BY clause, default (when null passed) is what comes from users_order_by_sql.
 881  * @param string $extrawheretest extra SQL conditions ANDed with the existing where clause.
 882  * @param array $whereorsortparams any parameters required by $extrawheretest (named parameters).
 883  * @return array Complex array as described above
 884  */
 885 function groups_get_members_by_role($groupid, $courseid, $fields='u.*',
 886         $sort=null, $extrawheretest='', $whereorsortparams=array()) {
 887     global $DB;
 888
 889     // Retrieve information about all users and their roles on the course or
 890     // parent ('related') contexts
 891     $context = context_course::instance($courseid);
 892
 893     // We are looking for all users with this role assigned in this context or higher.
 894     list($relatedctxsql, $relatedctxparams) = $DB->get_in_or_equal($context->get_parent_context_ids(true), SQL_PARAMS_NAMED, 'relatedctx');
 895
 896     if ($extrawheretest) {
 897         $extrawheretest = ' AND ' . $extrawheretest;
 898     }
 899
 900     if (is_null($sort)) {
 901         list($sort, $sortparams) = users_order_by_sql('u');
 902         $whereorsortparams = array_merge($whereorsortparams, $sortparams);
 903     }
 904
 905     $sql = "SELECT r.id AS roleid, u.id AS userid, $fields
 906               FROM {groups_members} gm
 907               JOIN {user} u ON u.id = gm.userid
 908          LEFT JOIN {role_assignments} ra ON (ra.userid = u.id AND ra.contextid $relatedctxsql)
 909          LEFT JOIN {role} r ON r.id = ra.roleid
 910              WHERE gm.groupid=:mgroupid
 911                    ".$extrawheretest."
 912           ORDER BY r.sortorder, $sort";
 913     $whereorsortparams = array_merge($whereorsortparams, $relatedctxparams, array('mgroupid' => $groupid));
 914     $rs = $DB->get_recordset_sql($sql, $whereorsortparams);
 915
 916     return groups_calculate_role_people($rs, $context);
 917 }
 918
 919 /**
 920  * Internal function used by groups_get_members_by_role to handle the
 921  * results of a database query that includes a list of users and possible
 922  * roles on a course.
 923  *
 924  * @param moodle_recordset $rs The record set (may be false)
 925  * @param int $context ID of course context
 926  * @return array As described in groups_get_members_by_role
 927  */
 928 function groups_calculate_role_people($rs, $context) {
 929     global $CFG, $DB;
 930
 931     if (!$rs) {
 932         return array();
 933     }
 934
 935     $allroles = role_fix_names(get_all_roles($context), $context);
 936
 937     // Array of all involved roles
 938     $roles = array();
 939     // Array of all retrieved users
 940     $users = array();
 941     // Fill arrays
 942     foreach ($rs as $rec) {
 943         // Create information about user if this is a new one
 944         if (!array_key_exists($rec->userid, $users)) {
 945             // User data includes all the optional fields, but not any of the
 946             // stuff we added to get the role details
 947             $userdata = clone($rec);
 948             unset($userdata->roleid);
 949             unset($userdata->roleshortname);
 950             unset($userdata->rolename);
 951             unset($userdata->userid);
 952             $userdata->id = $rec->userid;
 953
 954             // Make an array to hold the list of roles for this user
 955             $userdata->roles = array();
 956             $users[$rec->userid] = $userdata;
 957         }
 958         // If user has a role...
 959         if (!is_null($rec->roleid)) {
 960             // Create information about role if this is a new one
 961             if (!array_key_exists($rec->roleid, $roles)) {
 962                 $role = $allroles[$rec->roleid];
 963                 $roledata = new stdClass();
 964                 $roledata->id        = $role->id;
 965                 $roledata->shortname = $role->shortname;
 966                 $roledata->name      = $role->localname;
 967                 $roledata->users = array();
 968                 $roles[$roledata->id] = $roledata;
 969             }
 970             // Record that user has role
 971             $users[$rec->userid]->roles[$rec->roleid] = $roles[$rec->roleid];
 972         }
 973     }
 974     $rs->close();
 975
 976     // Return false if there weren't any users
 977     if (count($users) == 0) {
 978         return false;
 979     }
 980
 981     // Add pseudo-role for multiple roles
 982     $roledata = new stdClass();
 983     $roledata->name = get_string('multipleroles','role');
 984     $roledata->users = array();
 985     $roles['*'] = $roledata;
 986
 987     $roledata = new stdClass();
 988     $roledata->name = get_string('noroles','role');
 989     $roledata->users = array();
 990     $roles[0] = $roledata;
 991
 992     // Now we rearrange the data to store users by role
 993     foreach ($users as $userid=>$userdata) {
 994         $rolecount = count($userdata->roles);
 995         if ($rolecount == 0) {
 996             // does not have any roles
 997             $roleid = 0;
 998         } else if($rolecount > 1) {
 999             $roleid = '*';
1000         } else {
1001             $userrole = reset($userdata->roles);
1002             $roleid = $userrole->id;
1003         }
1004         $roles[$roleid]->users[$userid] = $userdata;
1005     }
1006
1007     // Delete roles not used
1008     foreach ($roles as $key=>$roledata) {
1009         if (count($roledata->users)===0) {
1010             unset($roles[$key]);
1011         }
1012     }
1013
1014     // Return list of roles containing their users
1015     return $roles;
1016 }