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 = $editform->save_temp_file('imagefile')) {
 350         if (process_new_icon($context, 'group', 'icon', $group->id, $iconfile)) {
 351             $DB->set_field('groups', 'picture', 1, array('id'=>$group->id));
 352             $group->picture = 1;
 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     $data->name         = trim($data->name);
 379     if (isset($data->idnumber)) {
 380         $data->idnumber = trim($data->idnumber);
 381         if (($existing = groups_get_group_by_idnumber($data->courseid, $data->idnumber)) && $existing->id != $data->id) {
 382             throw new moodle_exception('idnumbertaken');
 383         }
 384     }
 385
 386     if ($editform and $editoroptions) {
 387         $data = file_postupdate_standard_editor($data, 'description', $editoroptions, $context, 'group', 'description', $data->id);
 388     }
 389
 390     $DB->update_record('groups', $data);
 391
 392     // Invalidate the group data.
 393     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($data->courseid));
 394
 395     $group = $DB->get_record('groups', array('id'=>$data->id));
 396
 397     if ($editform) {
 398         groups_update_group_icon($group, $data, $editform);
 399     }
 400
 401     // Trigger group event.
 402     $params = array(
 403         'context' => $context,
 404         'objectid' => $group->id
 405     );
 406     $event = \core\event\group_updated::create($params);
 407     $event->add_record_snapshot('groups', $group);
 408     $event->trigger();
 409
 410     return true;
 411 }
 412
 413 /**
 414  * Update grouping
 415  *
 416  * @param stdClass $data grouping properties (with magic quotes)
 417  * @param array $editoroptions
 418  * @return bool true or exception
 419  */
 420 function groups_update_grouping($data, $editoroptions=null) {
 421     global $DB;
 422     $data->timemodified = time();
 423     $data->name         = trim($data->name);
 424     if (isset($data->idnumber)) {
 425         $data->idnumber = trim($data->idnumber);
 426         if (($existing = groups_get_grouping_by_idnumber($data->courseid, $data->idnumber)) && $existing->id != $data->id) {
 427             throw new moodle_exception('idnumbertaken');
 428         }
 429     }
 430     if ($editoroptions !== null) {
 431         $data = file_postupdate_standard_editor($data, 'description', $editoroptions, $editoroptions['context'], 'grouping', 'description', $data->id);
 432     }
 433     $DB->update_record('groupings', $data);
 434
 435     // Invalidate the group data.
 436     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($data->courseid));
 437
 438     // Trigger group event.
 439     $params = array(
 440         'context' => context_course::instance($data->courseid),
 441         'objectid' => $data->id
 442     );
 443     $event = \core\event\grouping_updated::create($params);
 444     $event->trigger();
 445
 446     return true;
 447 }
 448
 449 /**
 450  * Delete a group best effort, first removing members and links with courses and groupings.
 451  * Removes group avatar too.
 452  *
 453  * @param mixed $grouporid The id of group to delete or full group object
 454  * @return bool True if deletion was successful, false otherwise
 455  */
 456 function groups_delete_group($grouporid) {
 457     global $CFG, $DB;
 458     require_once("$CFG->libdir/gdlib.php");
 459
 460     if (is_object($grouporid)) {
 461         $groupid = $grouporid->id;
 462         $group   = $grouporid;
 463     } else {
 464         $groupid = $grouporid;
 465         if (!$group = $DB->get_record('groups', array('id'=>$groupid))) {
 466             //silently ignore attempts to delete missing already deleted groups ;-)
 467             return true;
 468         }
 469     }
 470
 471     // delete group calendar events
 472     $DB->delete_records('event', array('groupid'=>$groupid));
 473     //first delete usage in groupings_groups
 474     $DB->delete_records('groupings_groups', array('groupid'=>$groupid));
 475     //delete members
 476     $DB->delete_records('groups_members', array('groupid'=>$groupid));
 477     //group itself last
 478     $DB->delete_records('groups', array('id'=>$groupid));
 479
 480     // Delete all files associated with this group
 481     $context = context_course::instance($group->courseid);
 482     $fs = get_file_storage();
 483     $fs->delete_area_files($context->id, 'group', 'description', $groupid);
 484     $fs->delete_area_files($context->id, 'group', 'icon', $groupid);
 485
 486     // Invalidate the grouping cache for the course
 487     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($group->courseid));
 488
 489     // Trigger group event.
 490     $params = array(
 491         'context' => $context,
 492         'objectid' => $groupid
 493     );
 494     $event = \core\event\group_deleted::create($params);
 495     $event->add_record_snapshot('groups', $group);
 496     $event->trigger();
 497
 498     return true;
 499 }
 500
 501 /**
 502  * Delete grouping
 503  *
 504  * @param int $groupingorid
 505  * @return bool success
 506  */
 507 function groups_delete_grouping($groupingorid) {
 508     global $DB;
 509
 510     if (is_object($groupingorid)) {
 511         $groupingid = $groupingorid->id;
 512         $grouping   = $groupingorid;
 513     } else {
 514         $groupingid = $groupingorid;
 515         if (!$grouping = $DB->get_record('groupings', array('id'=>$groupingorid))) {
 516             //silently ignore attempts to delete missing already deleted groupings ;-)
 517             return true;
 518         }
 519     }
 520
 521     //first delete usage in groupings_groups
 522     $DB->delete_records('groupings_groups', array('groupingid'=>$groupingid));
 523     // remove the default groupingid from course
 524     $DB->set_field('course', 'defaultgroupingid', 0, array('defaultgroupingid'=>$groupingid));
 525     // remove the groupingid from all course modules
 526     $DB->set_field('course_modules', 'groupingid', 0, array('groupingid'=>$groupingid));
 527     //group itself last
 528     $DB->delete_records('groupings', array('id'=>$groupingid));
 529
 530     $context = context_course::instance($grouping->courseid);
 531     $fs = get_file_storage();
 532     $files = $fs->get_area_files($context->id, 'grouping', 'description', $groupingid);
 533     foreach ($files as $file) {
 534         $file->delete();
 535     }
 536
 537     // Invalidate the grouping cache for the course
 538     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($grouping->courseid));
 539
 540     // Trigger group event.
 541     $params = array(
 542         'context' => $context,
 543         'objectid' => $groupingid
 544     );
 545     $event = \core\event\grouping_deleted::create($params);
 546     $event->add_record_snapshot('groupings', $grouping);
 547     $event->trigger();
 548
 549     return true;
 550 }
 551
 552 /**
 553  * Remove all users (or one user) from all groups in course
 554  *
 555  * @param int $courseid
 556  * @param int $userid 0 means all users
 557  * @param bool $showfeedback
 558  * @return bool success
 559  */
 560 function groups_delete_group_members($courseid, $userid=0, $showfeedback=false) {
 561     global $DB, $OUTPUT;
 562
 563     if (is_bool($userid)) {
 564         debugging('Incorrect userid function parameter');
 565         return false;
 566     }
 567
 568     // Select * so that the function groups_remove_member() gets the whole record.
 569     $groups = $DB->get_recordset('groups', array('courseid' => $courseid));
 570     foreach ($groups as $group) {
 571         if ($userid) {
 572             $userids = array($userid);
 573         } else {
 574             $userids = $DB->get_fieldset_select('groups_members', 'userid', 'groupid = :groupid', array('groupid' => $group->id));
 575         }
 576
 577         foreach ($userids as $id) {
 578             groups_remove_member($group, $id);
 579         }
 580     }
 581
 582     // TODO MDL-41312 Remove events_trigger_legacy('groups_members_removed').
 583     // This event is kept here for backwards compatibility, because it cannot be
 584     // translated to a new event as it is wrong.
 585     $eventdata = new stdClass();
 586     $eventdata->courseid = $courseid;
 587     $eventdata->userid   = $userid;
 588     events_trigger_legacy('groups_members_removed', $eventdata);
 589
 590     if ($showfeedback) {
 591         echo $OUTPUT->notification(get_string('deleted').' - '.get_string('groupmembers', 'group'), 'notifysuccess');
 592     }
 593
 594     return true;
 595 }
 596
 597 /**
 598  * Remove all groups from all groupings in course
 599  *
 600  * @param int $courseid
 601  * @param bool $showfeedback
 602  * @return bool success
 603  */
 604 function groups_delete_groupings_groups($courseid, $showfeedback=false) {
 605     global $DB, $OUTPUT;
 606
 607     $groupssql = "SELECT id FROM {groups} g WHERE g.courseid = ?";
 608     $results = $DB->get_recordset_select('groupings_groups', "groupid IN ($groupssql)",
 609         array($courseid), '', 'groupid, groupingid');
 610
 611     foreach ($results as $result) {
 612         groups_unassign_grouping($result->groupingid, $result->groupid, false);
 613     }
 614
 615     // Invalidate the grouping cache for the course
 616     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 617
 618     // TODO MDL-41312 Remove events_trigger_legacy('groups_groupings_groups_removed').
 619     // This event is kept here for backwards compatibility, because it cannot be
 620     // translated to a new event as it is wrong.
 621     events_trigger_legacy('groups_groupings_groups_removed', $courseid);
 622
 623     // no need to show any feedback here - we delete usually first groupings and then groups
 624
 625     return true;
 626 }
 627
 628 /**
 629  * Delete all groups from course
 630  *
 631  * @param int $courseid
 632  * @param bool $showfeedback
 633  * @return bool success
 634  */
 635 function groups_delete_groups($courseid, $showfeedback=false) {
 636     global $CFG, $DB, $OUTPUT;
 637
 638     $groups = $DB->get_recordset('groups', array('courseid' => $courseid));
 639     foreach ($groups as $group) {
 640         groups_delete_group($group);
 641     }
 642
 643     // Invalidate the grouping cache for the course
 644     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 645
 646     // TODO MDL-41312 Remove events_trigger_legacy('groups_groups_deleted').
 647     // This event is kept here for backwards compatibility, because it cannot be
 648     // translated to a new event as it is wrong.
 649     events_trigger_legacy('groups_groups_deleted', $courseid);
 650
 651     if ($showfeedback) {
 652         echo $OUTPUT->notification(get_string('deleted').' - '.get_string('groups', 'group'), 'notifysuccess');
 653     }
 654
 655     return true;
 656 }
 657
 658 /**
 659  * Delete all groupings from course
 660  *
 661  * @param int $courseid
 662  * @param bool $showfeedback
 663  * @return bool success
 664  */
 665 function groups_delete_groupings($courseid, $showfeedback=false) {
 666     global $DB, $OUTPUT;
 667
 668     $groupings = $DB->get_recordset_select('groupings', 'courseid = ?', array($courseid));
 669     foreach ($groupings as $grouping) {
 670         groups_delete_grouping($grouping);
 671     }
 672
 673     // Invalidate the grouping cache for the course.
 674     cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 675
 676     // TODO MDL-41312 Remove events_trigger_legacy('groups_groupings_deleted').
 677     // This event is kept here for backwards compatibility, because it cannot be
 678     // translated to a new event as it is wrong.
 679     events_trigger_legacy('groups_groupings_deleted', $courseid);
 680
 681     if ($showfeedback) {
 682         echo $OUTPUT->notification(get_string('deleted').' - '.get_string('groupings', 'group'), 'notifysuccess');
 683     }
 684
 685     return true;
 686 }
 687
 688 /* =================================== */
 689 /* various functions used by groups UI */
 690 /* =================================== */
 691
 692 /**
 693  * Obtains a list of the possible roles that group members might come from,
 694  * on a course. Generally this includes only profile roles.
 695  *
 696  * @param context $context Context of course
 697  * @return Array of role ID integers, or false if error/none.
 698  */
 699 function groups_get_possible_roles($context) {
 700     $roles = get_profile_roles($context);
 701     return array_keys($roles);
 702 }
 703
 704
 705 /**
 706  * Gets potential group members for grouping
 707  *
 708  * @param int $courseid The id of the course
 709  * @param int $roleid The role to select users from
 710  * @param int $cohortid restrict to cohort id
 711  * @param string $orderby The column to sort users by
 712  * @return array An array of the users
 713  */
 714 function groups_get_potential_members($courseid, $roleid = null, $cohortid = null, $orderby = 'lastname ASC, firstname ASC') {
 715     global $DB;
 716
 717     $context = context_course::instance($courseid);
 718
 719     list($esql, $params) = get_enrolled_sql($context);
 720
 721     if ($roleid) {
 722         // We are looking for all users with this role assigned in this context or higher.
 723         list($relatedctxsql, $relatedctxparams) = $DB->get_in_or_equal($context->get_parent_context_ids(true), SQL_PARAMS_NAMED, 'relatedctx');
 724
 725         $params = array_merge($params, $relatedctxparams, array('roleid' => $roleid));
 726         $where = "WHERE u.id IN (SELECT userid
 727                                    FROM {role_assignments}
 728                                   WHERE roleid = :roleid AND contextid $relatedctxsql)";
 729     } else {
 730         $where = "";
 731     }
 732
 733     if ($cohortid) {
 734         $cohortjoin = "JOIN {cohort_members} cm ON (cm.userid = u.id AND cm.cohortid = :cohortid)";
 735         $params['cohortid'] = $cohortid;
 736     } else {
 737         $cohortjoin = "";
 738     }
 739
 740     $allusernamefields = get_all_user_name_fields(true, 'u');
 741     $sql = "SELECT u.id, u.username, $allusernamefields, u.idnumber
 742               FROM {user} u
 743               JOIN ($esql) e ON e.id = u.id
 744        $cohortjoin
 745             $where
 746           ORDER BY $orderby";
 747
 748     return $DB->get_records_sql($sql, $params);
 749
 750 }
 751
 752 /**
 753  * Parse a group name for characters to replace
 754  *
 755  * @param string $format The format a group name will follow
 756  * @param int $groupnumber The number of the group to be used in the parsed format string
 757  * @return string the parsed format string
 758  */
 759 function groups_parse_name($format, $groupnumber) {
 760     if (strstr($format, '@') !== false) { // Convert $groupnumber to a character series
 761         $letter = 'A';
 762         for($i=0; $i<$groupnumber; $i++) {
 763             $letter++;
 764         }
 765         $str = str_replace('@', $letter, $format);
 766     } else {
 767         $str = str_replace('#', $groupnumber+1, $format);
 768     }
 769     return($str);
 770 }
 771
 772 /**
 773  * Assigns group into grouping
 774  *
 775  * @param int groupingid
 776  * @param int groupid
 777  * @param int $timeadded  The time the group was added to the grouping.
 778  * @param bool $invalidatecache If set to true the course group cache will be invalidated as well.
 779  * @return bool true or exception
 780  */
 781 function groups_assign_grouping($groupingid, $groupid, $timeadded = null, $invalidatecache = true) {
 782     global $DB;
 783
 784     if ($DB->record_exists('groupings_groups', array('groupingid'=>$groupingid, 'groupid'=>$groupid))) {
 785         return true;
 786     }
 787     $assign = new stdClass();
 788     $assign->groupingid = $groupingid;
 789     $assign->groupid    = $groupid;
 790     if ($timeadded != null) {
 791         $assign->timeadded = (integer)$timeadded;
 792     } else {
 793         $assign->timeadded = time();
 794     }
 795     $DB->insert_record('groupings_groups', $assign);
 796
 797     if ($invalidatecache) {
 798         // Invalidate the grouping cache for the course
 799         $courseid = $DB->get_field('groupings', 'courseid', array('id' => $groupingid));
 800         cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 801     }
 802
 803     return true;
 804 }
 805
 806 /**
 807  * Unassigns group from grouping
 808  *
 809  * @param int groupingid
 810  * @param int groupid
 811  * @param bool $invalidatecache If set to true the course group cache will be invalidated as well.
 812  * @return bool success
 813  */
 814 function groups_unassign_grouping($groupingid, $groupid, $invalidatecache = true) {
 815     global $DB;
 816     $DB->delete_records('groupings_groups', array('groupingid'=>$groupingid, 'groupid'=>$groupid));
 817
 818     if ($invalidatecache) {
 819         // Invalidate the grouping cache for the course
 820         $courseid = $DB->get_field('groupings', 'courseid', array('id' => $groupingid));
 821         cache_helper::invalidate_by_definition('core', 'groupdata', array(), array($courseid));
 822     }
 823
 824     return true;
 825 }
 826
 827 /**
 828  * Lists users in a group based on their role on the course.
 829  * Returns false if there's an error or there are no users in the group.
 830  * Otherwise returns an array of role ID => role data, where role data includes:
 831  * (role) $id, $shortname, $name
 832  * $users: array of objects for each user which include the specified fields
 833  * Users who do not have a role are stored in the returned array with key '-'
 834  * and pseudo-role details (including a name, 'No role'). Users with multiple
 835  * roles, same deal with key '*' and name 'Multiple roles'. You can find out
 836  * which roles each has by looking in the $roles array of the user object.
 837  *
 838  * @param int $groupid
 839  * @param int $courseid Course ID (should match the group's course)
 840  * @param string $fields List of fields from user table prefixed with u, default 'u.*'
 841  * @param string $sort SQL ORDER BY clause, default (when null passed) is what comes from users_order_by_sql.
 842  * @param string $extrawheretest extra SQL conditions ANDed with the existing where clause.
 843  * @param array $whereorsortparams any parameters required by $extrawheretest (named parameters).
 844  * @return array Complex array as described above
 845  */
 846 function groups_get_members_by_role($groupid, $courseid, $fields='u.*',
 847         $sort=null, $extrawheretest='', $whereorsortparams=array()) {
 848     global $DB;
 849
 850     // Retrieve information about all users and their roles on the course or
 851     // parent ('related') contexts
 852     $context = context_course::instance($courseid);
 853
 854     // We are looking for all users with this role assigned in this context or higher.
 855     list($relatedctxsql, $relatedctxparams) = $DB->get_in_or_equal($context->get_parent_context_ids(true), SQL_PARAMS_NAMED, 'relatedctx');
 856
 857     if ($extrawheretest) {
 858         $extrawheretest = ' AND ' . $extrawheretest;
 859     }
 860
 861     if (is_null($sort)) {
 862         list($sort, $sortparams) = users_order_by_sql('u');
 863         $whereorsortparams = array_merge($whereorsortparams, $sortparams);
 864     }
 865
 866     $sql = "SELECT r.id AS roleid, u.id AS userid, $fields
 867               FROM {groups_members} gm
 868               JOIN {user} u ON u.id = gm.userid
 869          LEFT JOIN {role_assignments} ra ON (ra.userid = u.id AND ra.contextid $relatedctxsql)
 870          LEFT JOIN {role} r ON r.id = ra.roleid
 871              WHERE gm.groupid=:mgroupid
 872                    ".$extrawheretest."
 873           ORDER BY r.sortorder, $sort";
 874     $whereorsortparams = array_merge($whereorsortparams, $relatedctxparams, array('mgroupid' => $groupid));
 875     $rs = $DB->get_recordset_sql($sql, $whereorsortparams);
 876
 877     return groups_calculate_role_people($rs, $context);
 878 }
 879
 880 /**
 881  * Internal function used by groups_get_members_by_role to handle the
 882  * results of a database query that includes a list of users and possible
 883  * roles on a course.
 884  *
 885  * @param moodle_recordset $rs The record set (may be false)
 886  * @param int $context ID of course context
 887  * @return array As described in groups_get_members_by_role
 888  */
 889 function groups_calculate_role_people($rs, $context) {
 890     global $CFG, $DB;
 891
 892     if (!$rs) {
 893         return array();
 894     }
 895
 896     $allroles = role_fix_names(get_all_roles($context), $context);
 897
 898     // Array of all involved roles
 899     $roles = array();
 900     // Array of all retrieved users
 901     $users = array();
 902     // Fill arrays
 903     foreach ($rs as $rec) {
 904         // Create information about user if this is a new one
 905         if (!array_key_exists($rec->userid, $users)) {
 906             // User data includes all the optional fields, but not any of the
 907             // stuff we added to get the role details
 908             $userdata = clone($rec);
 909             unset($userdata->roleid);
 910             unset($userdata->roleshortname);
 911             unset($userdata->rolename);
 912             unset($userdata->userid);
 913             $userdata->id = $rec->userid;
 914
 915             // Make an array to hold the list of roles for this user
 916             $userdata->roles = array();
 917             $users[$rec->userid] = $userdata;
 918         }
 919         // If user has a role...
 920         if (!is_null($rec->roleid)) {
 921             // Create information about role if this is a new one
 922             if (!array_key_exists($rec->roleid, $roles)) {
 923                 $role = $allroles[$rec->roleid];
 924                 $roledata = new stdClass();
 925                 $roledata->id        = $role->id;
 926                 $roledata->shortname = $role->shortname;
 927                 $roledata->name      = $role->localname;
 928                 $roledata->users = array();
 929                 $roles[$roledata->id] = $roledata;
 930             }
 931             // Record that user has role
 932             $users[$rec->userid]->roles[$rec->roleid] = $roles[$rec->roleid];
 933         }
 934     }
 935     $rs->close();
 936
 937     // Return false if there weren't any users
 938     if (count($users) == 0) {
 939         return false;
 940     }
 941
 942     // Add pseudo-role for multiple roles
 943     $roledata = new stdClass();
 944     $roledata->name = get_string('multipleroles','role');
 945     $roledata->users = array();
 946     $roles['*'] = $roledata;
 947
 948     $roledata = new stdClass();
 949     $roledata->name = get_string('noroles','role');
 950     $roledata->users = array();
 951     $roles[0] = $roledata;
 952
 953     // Now we rearrange the data to store users by role
 954     foreach ($users as $userid=>$userdata) {
 955         $rolecount = count($userdata->roles);
 956         if ($rolecount == 0) {
 957             // does not have any roles
 958             $roleid = 0;
 959         } else if($rolecount > 1) {
 960             $roleid = '*';
 961         } else {
 962             $userrole = reset($userdata->roles);
 963             $roleid = $userrole->id;
 964         }
 965         $roles[$roleid]->users[$userid] = $userdata;
 966     }
 967
 968     // Delete roles not used
 969     foreach ($roles as $key=>$roledata) {
 970         if (count($roledata->users)===0) {
 971             unset($roles[$key]);
 972         }
 973     }
 974
 975     // Return list of roles containing their users
 976     return $roles;
 977 }