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     if (!is_enrolled(context_course::instance($group->courseid), $userid)) {
  69         return false;
  70     }
  71
  72     if (groups_is_member($groupid, $userid)) {
  73         return true;
  74     }
  75
  76     $member = new stdClass();
  77     $member->groupid   = $groupid;
  78     $member->userid    = $userid;
  79     $member->timeadded = time();
  80     $member->component = '';
  81     $member->itemid = 0;
  82
  83     // Check the component exists if specified
  84     if (!empty($component)) {
  85         $dir = get_component_directory($component);
  86         if ($dir && is_dir($dir)) {
  87             // Component exists and can be used
  88             $member->component = $component;
  89             $member->itemid = $itemid;
  90         } else {
  91             throw new coding_exception('Invalid call to groups_add_member(). An invalid component was specified');
  92         }
  93     }
  94
  95     if ($itemid !== 0 && empty($member->component)) {
  96         // An itemid can only be specified if a valid component was found
  97         throw new coding_exception('Invalid call to groups_add_member(). A component must be specified if an itemid is given');
  98     }
  99
 100     $DB->insert_record('groups_members', $member);
 101
 102     //update group info
 103     $DB->set_field('groups', 'timemodified', $member->timeadded, array('id'=>$groupid));
 104
 105     //trigger groups events
 106     $eventdata = new stdClass();
 107     $eventdata->groupid = $groupid;
 108     $eventdata->userid  = $userid;
 109     $eventdata->component = $member->component;
 110     $eventdata->itemid = $member->itemid;
 111     events_trigger('groups_member_added', $eventdata);
 112
 113     return true;
 114 }
 115
 116 /**
 117  * Checks whether the current user is permitted (using the normal UI) to
 118  * remove a specific group member, assuming that they have access to remove
 119  * group members in general.
 120  *
 121  * For automatically-created group member entries, this checks with the
 122  * relevant plugin to see whether it is permitted. The default, if the plugin
 123  * doesn't provide a function, is true.
 124  *
 125  * For other entries (and any which have already been deleted/don't exist) it
 126  * just returns true.
 127  *
 128  * @param mixed $grouporid The group id or group object
 129  * @param mixed $userorid The user id or user object
 130  * @return bool True if permitted, false otherwise
 131  */
 132 function groups_remove_member_allowed($grouporid, $userorid) {
 133     global $DB;
 134
 135     if (is_object($userorid)) {
 136         $userid = $userorid->id;
 137     } else {
 138         $userid = $userorid;
 139     }
 140     if (is_object($grouporid)) {
 141         $groupid = $grouporid->id;
 142     } else {
 143         $groupid = $grouporid;
 144     }
 145
 146     // Get entry
 147     if (!($entry = $DB->get_record('groups_members',
 148             array('groupid' => $groupid, 'userid' => $userid), '*', IGNORE_MISSING))) {
 149         // If the entry does not exist, they are allowed to remove it (this
 150         // is consistent with groups_remove_member below).
 151         return true;
 152     }
 153
 154     // If the entry does not have a component value, they can remove it
 155     if (empty($entry->component)) {
 156         return true;
 157     }
 158
 159     // It has a component value, so we need to call a plugin function (if it
 160     // exists); the default is to allow removal
 161     return component_callback($entry->component, 'allow_group_member_remove',
 162             array($entry->itemid, $entry->groupid, $entry->userid), true);
 163 }
 164
 165 /**
 166  * Deletes the link between the specified user and group.
 167  *
 168  * @param mixed $grouporid  The group id or group object
 169  * @param mixed $userorid   The user id or user object
 170  * @return bool True if deletion was successful, false otherwise
 171  */
 172 function groups_remove_member($grouporid, $userorid) {
 173     global $DB;
 174
 175     if (is_object($userorid)) {
 176         $userid = $userorid->id;
 177         $user   = $userorid;
 178     } else {
 179         $userid = $userorid;
 180         $user = $DB->get_record('user', array('id'=>$userid), '*', MUST_EXIST);
 181     }
 182
 183     if (is_object($grouporid)) {
 184         $groupid = $grouporid->id;
 185         $group   = $grouporid;
 186     } else {
 187         $groupid = $grouporid;
 188         $group = $DB->get_record('groups', array('id'=>$groupid), '*', MUST_EXIST);
 189     }
 190
 191     if (!groups_is_member($groupid, $userid)) {
 192         return true;
 193     }
 194
 195     $DB->delete_records('groups_members', array('groupid'=>$groupid, 'userid'=>$userid));
 196
 197     //update group info
 198     $DB->set_field('groups', 'timemodified', time(), array('id'=>$groupid));
 199
 200     //trigger groups events
 201     $eventdata = new stdClass();
 202     $eventdata->groupid = $groupid;
 203     $eventdata->userid  = $userid;
 204     events_trigger('groups_member_removed', $eventdata);
 205
 206     return true;
 207 }
 208
 209 /**
 210  * Add a new group
 211  *
 212  * @param stdClass $data group properties
 213  * @param stdClass $editform
 214  * @param array $editoroptions
 215  * @return id of group or false if error
 216  */
 217 function groups_create_group($data, $editform = false, $editoroptions = false) {
 218     global $CFG, $DB;
 219
 220     //check that courseid exists
 221     $course = $DB->get_record('course', array('id' => $data->courseid), '*', MUST_EXIST);
 222     $context = context_course::instance($course->id);
 223
 224     $data->timecreated  = time();
 225     $data->timemodified = $data->timecreated;
 226     $data->name         = trim($data->name);
 227     if (isset($data->idnumber)) {
 228         $data->idnumber = trim($data->idnumber);
 229         if (groups_get_group_by_idnumber($course->id, $data->idnumber)) {
 230             throw new moodle_exception('idnumbertaken');
 231         }
 232     }
 233
 234     if ($editform and $editoroptions) {
 235         $data->description = $data->description_editor['text'];
 236         $data->descriptionformat = $data->description_editor['format'];
 237     }
 238
 239     $data->id = $DB->insert_record('groups', $data);
 240
 241     if ($editform and $editoroptions) {
 242         // Update description from editor with fixed files
 243         $data = file_postupdate_standard_editor($data, 'description', $editoroptions, $context, 'group', 'description', $data->id);
 244         $upd = new stdClass();
 245         $upd->id                = $data->id;
 246         $upd->description       = $data->description;
 247         $upd->descriptionformat = $data->descriptionformat;
 248         $DB->update_record('groups', $upd);
 249     }
 250
 251     $group = $DB->get_record('groups', array('id'=>$data->id));
 252
 253     if ($editform) {
 254         groups_update_group_icon($group, $data, $editform);
 255     }
 256
 257     //trigger groups events
 258     events_trigger('groups_group_created', $group);
 259
 260     return $group->id;
 261 }
 262
 263 /**
 264  * Add a new grouping
 265  *
 266  * @param stdClass $data grouping properties
 267  * @param array $editoroptions
 268  * @return id of grouping or false if error
 269  */
 270 function groups_create_grouping($data, $editoroptions=null) {
 271     global $DB;
 272
 273     $data->timecreated  = time();
 274     $data->timemodified = $data->timecreated;
 275     $data->name         = trim($data->name);
 276     if (isset($data->idnumber)) {
 277         $data->idnumber = trim($data->idnumber);
 278         if (groups_get_grouping_by_idnumber($data->courseid, $data->idnumber)) {
 279             throw new moodle_exception('idnumbertaken');
 280         }
 281     }
 282
 283     if ($editoroptions !== null) {
 284         $data->description = $data->description_editor['text'];
 285         $data->descriptionformat = $data->description_editor['format'];
 286     }
 287
 288     $id = $DB->insert_record('groupings', $data);
 289
 290     //trigger groups events
 291     $data->id = $id;
 292
 293     if ($editoroptions !== null) {
 294         $description = new stdClass;
 295         $description->id = $data->id;
 296         $description->description_editor = $data->description_editor;
 297         $description = file_postupdate_standard_editor($description, 'description', $editoroptions, $editoroptions['context'], 'grouping', 'description', $description->id);
 298         $DB->update_record('groupings', $description);
 299     }
 300
 301     events_trigger('groups_grouping_created', $data);
 302
 303     return $id;
 304 }
 305
 306 /**
 307  * Update the group icon from form data
 308  *
 309  * @param stdClass $group group information
 310  * @param stdClass $data
 311  * @param stdClass $editform
 312  */
 313 function groups_update_group_icon($group, $data, $editform) {
 314     global $CFG, $DB;
 315     require_once("$CFG->libdir/gdlib.php");
 316
 317     $fs = get_file_storage();
 318     $context = context_course::instance($group->courseid, MUST_EXIST);
 319
 320     //TODO: it would make sense to allow picture deleting too (skodak)
 321     if (!empty($CFG->gdversion)) {
 322         if ($iconfile = $editform->save_temp_file('imagefile')) {
 323             if (process_new_icon($context, 'group', 'icon', $group->id, $iconfile)) {
 324                 $DB->set_field('groups', 'picture', 1, array('id'=>$group->id));
 325                 $group->picture = 1;
 326             } else {
 327                 $fs->delete_area_files($context->id, 'group', 'icon', $group->id);
 328                 $DB->set_field('groups', 'picture', 0, array('id'=>$group->id));
 329                 $group->picture = 0;
 330             }
 331             @unlink($iconfile);
 332         }
 333     }
 334 }
 335
 336 /**
 337  * Update group
 338  *
 339  * @param stdClass $data group properties (with magic quotes)
 340  * @param stdClass $editform
 341  * @param array $editoroptions
 342  * @return bool true or exception
 343  */
 344 function groups_update_group($data, $editform = false, $editoroptions = false) {
 345     global $CFG, $DB;
 346
 347     $context = context_course::instance($data->courseid);
 348
 349     $data->timemodified = time();
 350     $data->name         = trim($data->name);
 351     if (isset($data->idnumber)) {
 352         $data->idnumber = trim($data->idnumber);
 353         if (($existing = groups_get_group_by_idnumber($data->courseid, $data->idnumber)) && $existing->id != $data->id) {
 354             throw new moodle_exception('idnumbertaken');
 355         }
 356     }
 357
 358     if ($editform and $editoroptions) {
 359         $data = file_postupdate_standard_editor($data, 'description', $editoroptions, $context, 'group', 'description', $data->id);
 360     }
 361
 362     $DB->update_record('groups', $data);
 363
 364     $group = $DB->get_record('groups', array('id'=>$data->id));
 365
 366     if ($editform) {
 367         groups_update_group_icon($group, $data, $editform);
 368     }
 369
 370     //trigger groups events
 371     events_trigger('groups_group_updated', $group);
 372
 373
 374     return true;
 375 }
 376
 377 /**
 378  * Update grouping
 379  *
 380  * @param stdClass $data grouping properties (with magic quotes)
 381  * @param array $editoroptions
 382  * @return bool true or exception
 383  */
 384 function groups_update_grouping($data, $editoroptions=null) {
 385     global $DB;
 386     $data->timemodified = time();
 387     $data->name         = trim($data->name);
 388     if (isset($data->idnumber)) {
 389         $data->idnumber = trim($data->idnumber);
 390         if (($existing = groups_get_grouping_by_idnumber($data->courseid, $data->idnumber)) && $existing->id != $data->id) {
 391             throw new moodle_exception('idnumbertaken');
 392         }
 393     }
 394     if ($editoroptions !== null) {
 395         $data = file_postupdate_standard_editor($data, 'description', $editoroptions, $editoroptions['context'], 'grouping', 'description', $data->id);
 396     }
 397     $DB->update_record('groupings', $data);
 398     //trigger groups events
 399     events_trigger('groups_grouping_updated', $data);
 400
 401     return true;
 402 }
 403
 404 /**
 405  * Delete a group best effort, first removing members and links with courses and groupings.
 406  * Removes group avatar too.
 407  *
 408  * @param mixed $grouporid The id of group to delete or full group object
 409  * @return bool True if deletion was successful, false otherwise
 410  */
 411 function groups_delete_group($grouporid) {
 412     global $CFG, $DB;
 413     require_once("$CFG->libdir/gdlib.php");
 414
 415     if (is_object($grouporid)) {
 416         $groupid = $grouporid->id;
 417         $group   = $grouporid;
 418     } else {
 419         $groupid = $grouporid;
 420         if (!$group = $DB->get_record('groups', array('id'=>$groupid))) {
 421             //silently ignore attempts to delete missing already deleted groups ;-)
 422             return true;
 423         }
 424     }
 425
 426     // delete group calendar events
 427     $DB->delete_records('event', array('groupid'=>$groupid));
 428     //first delete usage in groupings_groups
 429     $DB->delete_records('groupings_groups', array('groupid'=>$groupid));
 430     //delete members
 431     $DB->delete_records('groups_members', array('groupid'=>$groupid));
 432     //group itself last
 433     $DB->delete_records('groups', array('id'=>$groupid));
 434
 435     // Delete all files associated with this group
 436     $context = context_course::instance($group->courseid);
 437     $fs = get_file_storage();
 438     $fs->delete_area_files($context->id, 'group', 'description', $groupid);
 439     $fs->delete_area_files($context->id, 'group', 'icon', $groupid);
 440
 441     //trigger groups events
 442     events_trigger('groups_group_deleted', $group);
 443
 444     return true;
 445 }
 446
 447 /**
 448  * Delete grouping
 449  *
 450  * @param int $groupingorid
 451  * @return bool success
 452  */
 453 function groups_delete_grouping($groupingorid) {
 454     global $DB;
 455
 456     if (is_object($groupingorid)) {
 457         $groupingid = $groupingorid->id;
 458         $grouping   = $groupingorid;
 459     } else {
 460         $groupingid = $groupingorid;
 461         if (!$grouping = $DB->get_record('groupings', array('id'=>$groupingorid))) {
 462             //silently ignore attempts to delete missing already deleted groupings ;-)
 463             return true;
 464         }
 465     }
 466
 467     //first delete usage in groupings_groups
 468     $DB->delete_records('groupings_groups', array('groupingid'=>$groupingid));
 469     // remove the default groupingid from course
 470     $DB->set_field('course', 'defaultgroupingid', 0, array('defaultgroupingid'=>$groupingid));
 471     // remove the groupingid from all course modules
 472     $DB->set_field('course_modules', 'groupingid', 0, array('groupingid'=>$groupingid));
 473     //group itself last
 474     $DB->delete_records('groupings', array('id'=>$groupingid));
 475
 476     $context = context_course::instance($grouping->courseid);
 477     $fs = get_file_storage();
 478     $files = $fs->get_area_files($context->id, 'grouping', 'description', $groupingid);
 479     foreach ($files as $file) {
 480         $file->delete();
 481     }
 482
 483     //trigger groups events
 484     events_trigger('groups_grouping_deleted', $grouping);
 485
 486     return true;
 487 }
 488
 489 /**
 490  * Remove all users (or one user) from all groups in course
 491  *
 492  * @param int $courseid
 493  * @param int $userid 0 means all users
 494  * @param bool $showfeedback
 495  * @return bool success
 496  */
 497 function groups_delete_group_members($courseid, $userid=0, $showfeedback=false) {
 498     global $DB, $OUTPUT;
 499
 500     if (is_bool($userid)) {
 501         debugging('Incorrect userid function parameter');
 502         return false;
 503     }
 504
 505     $params = array('courseid'=>$courseid);
 506
 507     if ($userid) {
 508         $usersql = "AND userid = :userid";
 509         $params['userid'] = $userid;
 510     } else {
 511         $usersql = "";
 512     }
 513
 514     $groupssql = "SELECT id FROM {groups} g WHERE g.courseid = :courseid";
 515     $DB->delete_records_select('groups_members', "groupid IN ($groupssql) $usersql", $params);
 516
 517     //trigger groups events
 518     $eventdata = new stdClass();
 519     $eventdata->courseid = $courseid;
 520     $eventdata->userid   = $userid;
 521     events_trigger('groups_members_removed', $eventdata);
 522
 523     if ($showfeedback) {
 524         echo $OUTPUT->notification(get_string('deleted').' - '.get_string('groupmembers', 'group'), 'notifysuccess');
 525     }
 526
 527     return true;
 528 }
 529
 530 /**
 531  * Remove all groups from all groupings in course
 532  *
 533  * @param int $courseid
 534  * @param bool $showfeedback
 535  * @return bool success
 536  */
 537 function groups_delete_groupings_groups($courseid, $showfeedback=false) {
 538     global $DB, $OUTPUT;
 539
 540     $groupssql = "SELECT id FROM {groups} g WHERE g.courseid = ?";
 541     $DB->delete_records_select('groupings_groups', "groupid IN ($groupssql)", array($courseid));
 542
 543     //trigger groups events
 544     events_trigger('groups_groupings_groups_removed', $courseid);
 545
 546     // no need to show any feedback here - we delete usually first groupings and then groups
 547
 548     return true;
 549 }
 550
 551 /**
 552  * Delete all groups from course
 553  *
 554  * @param int $courseid
 555  * @param bool $showfeedback
 556  * @return bool success
 557  */
 558 function groups_delete_groups($courseid, $showfeedback=false) {
 559     global $CFG, $DB, $OUTPUT;
 560
 561     // delete any uses of groups
 562     // Any associated files are deleted as part of groups_delete_groupings_groups
 563     groups_delete_groupings_groups($courseid, $showfeedback);
 564     groups_delete_group_members($courseid, 0, $showfeedback);
 565
 566     // delete group pictures and descriptions
 567     $context = context_course::instance($courseid);
 568     $fs = get_file_storage();
 569     $fs->delete_area_files($context->id, 'group');
 570
 571     // delete group calendar events
 572     $groupssql = "SELECT id FROM {groups} g WHERE g.courseid = ?";
 573     $DB->delete_records_select('event', "groupid IN ($groupssql)", array($courseid));
 574
 575     $context = context_course::instance($courseid);
 576     $fs = get_file_storage();
 577     $fs->delete_area_files($context->id, 'group');
 578
 579     $DB->delete_records('groups', array('courseid'=>$courseid));
 580
 581     // trigger groups events
 582     events_trigger('groups_groups_deleted', $courseid);
 583
 584     if ($showfeedback) {
 585         echo $OUTPUT->notification(get_string('deleted').' - '.get_string('groups', 'group'), 'notifysuccess');
 586     }
 587
 588     return true;
 589 }
 590
 591 /**
 592  * Delete all groupings from course
 593  *
 594  * @param int $courseid
 595  * @param bool $showfeedback
 596  * @return bool success
 597  */
 598 function groups_delete_groupings($courseid, $showfeedback=false) {
 599     global $DB, $OUTPUT;
 600
 601     // delete any uses of groupings
 602     $sql = "DELETE FROM {groupings_groups}
 603              WHERE groupingid in (SELECT id FROM {groupings} g WHERE g.courseid = ?)";
 604     $DB->execute($sql, array($courseid));
 605
 606     // remove the default groupingid from course
 607     $DB->set_field('course', 'defaultgroupingid', 0, array('id'=>$courseid));
 608     // remove the groupingid from all course modules
 609     $DB->set_field('course_modules', 'groupingid', 0, array('course'=>$courseid));
 610
 611     // Delete all files associated with groupings for this course
 612     $context = context_course::instance($courseid);
 613     $fs = get_file_storage();
 614     $fs->delete_area_files($context->id, 'grouping');
 615
 616     $DB->delete_records('groupings', array('courseid'=>$courseid));
 617
 618     // trigger groups events
 619     events_trigger('groups_groupings_deleted', $courseid);
 620
 621     if ($showfeedback) {
 622         echo $OUTPUT->notification(get_string('deleted').' - '.get_string('groupings', 'group'), 'notifysuccess');
 623     }
 624
 625     return true;
 626 }
 627
 628 /* =================================== */
 629 /* various functions used by groups UI */
 630 /* =================================== */
 631
 632 /**
 633  * Obtains a list of the possible roles that group members might come from,
 634  * on a course. Generally this includes only profile roles.
 635  *
 636  * @param context $context Context of course
 637  * @return Array of role ID integers, or false if error/none.
 638  */
 639 function groups_get_possible_roles($context) {
 640     $roles = get_profile_roles($context);
 641     return array_keys($roles);
 642 }
 643
 644
 645 /**
 646  * Gets potential group members for grouping
 647  *
 648  * @param int $courseid The id of the course
 649  * @param int $roleid The role to select users from
 650  * @param int $cohortid restrict to cohort id
 651  * @param string $orderby The column to sort users by
 652  * @return array An array of the users
 653  */
 654 function groups_get_potential_members($courseid, $roleid = null, $cohortid = null, $orderby = 'lastname ASC, firstname ASC') {
 655     global $DB;
 656
 657     $context = context_course::instance($courseid);
 658
 659     // we are looking for all users with this role assigned in this context or higher
 660     $listofcontexts = get_related_contexts_string($context);
 661
 662     list($esql, $params) = get_enrolled_sql($context);
 663
 664     if ($roleid) {
 665         $params['roleid'] = $roleid;
 666         $where = "WHERE u.id IN (SELECT userid
 667                                    FROM {role_assignments}
 668                                   WHERE roleid = :roleid AND contextid $listofcontexts)";
 669     } else {
 670         $where = "";
 671     }
 672
 673     if ($cohortid) {
 674         $cohortjoin = "JOIN {cohort_members} cm ON (cm.userid = u.id AND cm.cohortid = :cohortid)";
 675         $params['cohortid'] = $cohortid;
 676     } else {
 677         $cohortjoin = "";
 678     }
 679
 680     $sql = "SELECT u.id, u.username, u.firstname, u.lastname, u.idnumber
 681               FROM {user} u
 682               JOIN ($esql) e ON e.id = u.id
 683        $cohortjoin
 684             $where
 685           ORDER BY $orderby";
 686
 687     return $DB->get_records_sql($sql, $params);
 688
 689 }
 690
 691 /**
 692  * Parse a group name for characters to replace
 693  *
 694  * @param string $format The format a group name will follow
 695  * @param int $groupnumber The number of the group to be used in the parsed format string
 696  * @return string the parsed format string
 697  */
 698 function groups_parse_name($format, $groupnumber) {
 699     if (strstr($format, '@') !== false) { // Convert $groupnumber to a character series
 700         $letter = 'A';
 701         for($i=0; $i<$groupnumber; $i++) {
 702             $letter++;
 703         }
 704         $str = str_replace('@', $letter, $format);
 705     } else {
 706         $str = str_replace('#', $groupnumber+1, $format);
 707     }
 708     return($str);
 709 }
 710
 711 /**
 712  * Assigns group into grouping
 713  *
 714  * @param int groupingid
 715  * @param int groupid
 716  * @param int $timeadded  The time the group was added to the grouping.
 717  * @return bool true or exception
 718  */
 719 function groups_assign_grouping($groupingid, $groupid, $timeadded = null) {
 720     global $DB;
 721
 722     if ($DB->record_exists('groupings_groups', array('groupingid'=>$groupingid, 'groupid'=>$groupid))) {
 723         return true;
 724     }
 725     $assign = new stdClass();
 726     $assign->groupingid = $groupingid;
 727     $assign->groupid    = $groupid;
 728     if ($timeadded != null) {
 729         $assign->timeadded = (integer)$timeadded;
 730     } else {
 731         $assign->timeadded = time();
 732     }
 733     $DB->insert_record('groupings_groups', $assign);
 734
 735     return true;
 736 }
 737
 738 /**
 739  * Unassigns group grom grouping
 740  *
 741  * @param int groupingid
 742  * @param int groupid
 743  * @return bool success
 744  */
 745 function groups_unassign_grouping($groupingid, $groupid) {
 746     global $DB;
 747     $DB->delete_records('groupings_groups', array('groupingid'=>$groupingid, 'groupid'=>$groupid));
 748
 749     return true;
 750 }
 751
 752 /**
 753  * Lists users in a group based on their role on the course.
 754  * Returns false if there's an error or there are no users in the group.
 755  * Otherwise returns an array of role ID => role data, where role data includes:
 756  * (role) $id, $shortname, $name
 757  * $users: array of objects for each user which include the specified fields
 758  * Users who do not have a role are stored in the returned array with key '-'
 759  * and pseudo-role details (including a name, 'No role'). Users with multiple
 760  * roles, same deal with key '*' and name 'Multiple roles'. You can find out
 761  * which roles each has by looking in the $roles array of the user object.
 762  *
 763  * @param int $groupid
 764  * @param int $courseid Course ID (should match the group's course)
 765  * @param string $fields List of fields from user table prefixed with u, default 'u.*'
 766  * @param string $sort SQL ORDER BY clause, default (when null passed) is what comes from users_order_by_sql.
 767  * @param string $extrawheretest extra SQL conditions ANDed with the existing where clause.
 768  * @param array $whereorsortparams any parameters required by $extrawheretest (named parameters).
 769  * @return array Complex array as described above
 770  */
 771 function groups_get_members_by_role($groupid, $courseid, $fields='u.*',
 772         $sort=null, $extrawheretest='', $whereorsortparams=array()) {
 773     global $CFG, $DB;
 774
 775     // Retrieve information about all users and their roles on the course or
 776     // parent ('related') contexts
 777     $context = context_course::instance($courseid);
 778
 779     if ($extrawheretest) {
 780         $extrawheretest = ' AND ' . $extrawheretest;
 781     }
 782
 783     if (is_null($sort)) {
 784         list($sort, $sortparams) = users_order_by_sql('u');
 785         $whereorsortparams = array_merge($whereorsortparams, $sortparams);
 786     }
 787
 788     $sql = "SELECT r.id AS roleid, u.id AS userid, $fields
 789               FROM {groups_members} gm
 790               JOIN {user} u ON u.id = gm.userid
 791          LEFT JOIN {role_assignments} ra ON (ra.userid = u.id AND ra.contextid ".get_related_contexts_string($context).")
 792          LEFT JOIN {role} r ON r.id = ra.roleid
 793              WHERE gm.groupid=:mgroupid
 794                    ".$extrawheretest."
 795           ORDER BY r.sortorder, $sort";
 796     $whereorsortparams['mgroupid'] = $groupid;
 797     $rs = $DB->get_recordset_sql($sql, $whereorsortparams);
 798
 799     return groups_calculate_role_people($rs, $context);
 800 }
 801
 802 /**
 803  * Internal function used by groups_get_members_by_role to handle the
 804  * results of a database query that includes a list of users and possible
 805  * roles on a course.
 806  *
 807  * @param moodle_recordset $rs The record set (may be false)
 808  * @param int $context ID of course context
 809  * @return array As described in groups_get_members_by_role
 810  */
 811 function groups_calculate_role_people($rs, $context) {
 812     global $CFG, $DB;
 813
 814     if (!$rs) {
 815         return array();
 816     }
 817
 818     $allroles = role_fix_names(get_all_roles($context), $context);
 819
 820     // Array of all involved roles
 821     $roles = array();
 822     // Array of all retrieved users
 823     $users = array();
 824     // Fill arrays
 825     foreach ($rs as $rec) {
 826         // Create information about user if this is a new one
 827         if (!array_key_exists($rec->userid, $users)) {
 828             // User data includes all the optional fields, but not any of the
 829             // stuff we added to get the role details
 830             $userdata = clone($rec);
 831             unset($userdata->roleid);
 832             unset($userdata->roleshortname);
 833             unset($userdata->rolename);
 834             unset($userdata->userid);
 835             $userdata->id = $rec->userid;
 836
 837             // Make an array to hold the list of roles for this user
 838             $userdata->roles = array();
 839             $users[$rec->userid] = $userdata;
 840         }
 841         // If user has a role...
 842         if (!is_null($rec->roleid)) {
 843             // Create information about role if this is a new one
 844             if (!array_key_exists($rec->roleid, $roles)) {
 845                 $role = $allroles[$rec->roleid];
 846                 $roledata = new stdClass();
 847                 $roledata->id        = $role->id;
 848                 $roledata->shortname = $role->shortname;
 849                 $roledata->name      = $role->localname;
 850                 $roledata->users = array();
 851                 $roles[$roledata->id] = $roledata;
 852             }
 853             // Record that user has role
 854             $users[$rec->userid]->roles[$rec->roleid] = $roles[$rec->roleid];
 855         }
 856     }
 857     $rs->close();
 858
 859     // Return false if there weren't any users
 860     if (count($users) == 0) {
 861         return false;
 862     }
 863
 864     // Add pseudo-role for multiple roles
 865     $roledata = new stdClass();
 866     $roledata->name = get_string('multipleroles','role');
 867     $roledata->users = array();
 868     $roles['*'] = $roledata;
 869
 870     $roledata = new stdClass();
 871     $roledata->name = get_string('noroles','role');
 872     $roledata->users = array();
 873     $roles[0] = $roledata;
 874
 875     // Now we rearrange the data to store users by role
 876     foreach ($users as $userid=>$userdata) {
 877         $rolecount = count($userdata->roles);
 878         if ($rolecount == 0) {
 879             // does not have any roles
 880             $roleid = 0;
 881         } else if($rolecount > 1) {
 882             $roleid = '*';
 883         } else {
 884             $userrole = reset($userdata->roles);
 885             $roleid = $userrole->id;
 886         }
 887         $roles[$roleid]->users[$userid] = $userdata;
 888     }
 889
 890     // Delete roles not used
 891     foreach ($roles as $key=>$roledata) {
 892         if (count($roledata->users)===0) {
 893             unset($roles[$key]);
 894         }
 895     }
 896
 897     // Return list of roles containing their users
 898     return $roles;
 899 }