lib/grouplib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * @copyright  1999 onwards Martin Dougiamas  {@link http://moodle.com}
  20  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  21  * @package    core_group
  22  */
  23
  24 defined('MOODLE_INTERNAL') || die();
  25
  26 /**
  27  * Groups not used in course or activity
  28  */
  29 define('NOGROUPS', 0);
  30
  31 /**
  32  * Groups used, users do not see other groups
  33  */
  34 define('SEPARATEGROUPS', 1);
  35
  36 /**
  37  * Groups used, students see other groups
  38  */
  39 define('VISIBLEGROUPS', 2);
  40
  41
  42 /**
  43  * Determines if a group with a given groupid exists.
  44  *
  45  * @category group
  46  * @param int $groupid The groupid to check for
  47  * @return bool True if the group exists, false otherwise or if an error
  48  * occurred.
  49  */
  50 function groups_group_exists($groupid) {
  51     global $DB;
  52     return $DB->record_exists('groups', array('id'=>$groupid));
  53 }
  54
  55 /**
  56  * Gets the name of a group with a specified id
  57  *
  58  * @category group
  59  * @param int $groupid The id of the group
  60  * @return string The name of the group
  61  */
  62 function groups_get_group_name($groupid) {
  63     global $DB;
  64     return $DB->get_field('groups', 'name', array('id'=>$groupid));
  65 }
  66
  67 /**
  68  * Gets the name of a grouping with a specified id
  69  *
  70  * @category group
  71  * @param int $groupingid The id of the grouping
  72  * @return string The name of the grouping
  73  */
  74 function groups_get_grouping_name($groupingid) {
  75     global $DB;
  76     return $DB->get_field('groupings', 'name', array('id'=>$groupingid));
  77 }
  78
  79 /**
  80  * Returns the groupid of a group with the name specified for the course.
  81  * Group names should be unique in course
  82  *
  83  * @category group
  84  * @param int $courseid The id of the course
  85  * @param string $name name of group (without magic quotes)
  86  * @return int $groupid
  87  */
  88 function groups_get_group_by_name($courseid, $name) {
  89     $data = groups_get_course_data($courseid);
  90     foreach ($data->groups as $group) {
  91         if ($group->name == $name) {
  92             return $group->id;
  93         }
  94     }
  95     return false;
  96 }
  97
  98 /**
  99  * Returns the groupid of a group with the idnumber specified for the course.
 100  * Group idnumbers should be unique within course
 101  *
 102  * @category group
 103  * @param int $courseid The id of the course
 104  * @param string $idnumber idnumber of group
 105  * @return group object
 106  */
 107 function groups_get_group_by_idnumber($courseid, $idnumber) {
 108     if (empty($idnumber)) {
 109         return false;
 110     }
 111     $data = groups_get_course_data($courseid);
 112     foreach ($data->groups as $group) {
 113         if ($group->idnumber == $idnumber) {
 114             return $group;
 115         }
 116     }
 117     return false;
 118 }
 119
 120 /**
 121  * Returns the groupingid of a grouping with the name specified for the course.
 122  * Grouping names should be unique in course
 123  *
 124  * @category group
 125  * @param int $courseid The id of the course
 126  * @param string $name name of group (without magic quotes)
 127  * @return int $groupid
 128  */
 129 function groups_get_grouping_by_name($courseid, $name) {
 130     $data = groups_get_course_data($courseid);
 131     foreach ($data->groupings as $grouping) {
 132         if ($grouping->name == $name) {
 133             return $grouping->id;
 134         }
 135     }
 136     return false;
 137 }
 138
 139 /**
 140  * Returns the groupingid of a grouping with the idnumber specified for the course.
 141  * Grouping names should be unique within course
 142  *
 143  * @category group
 144  * @param int $courseid The id of the course
 145  * @param string $idnumber idnumber of the group
 146  * @return grouping object
 147  */
 148 function groups_get_grouping_by_idnumber($courseid, $idnumber) {
 149     if (empty($idnumber)) {
 150         return false;
 151     }
 152     $data = groups_get_course_data($courseid);
 153     foreach ($data->groupings as $grouping) {
 154         if ($grouping->idnumber == $idnumber) {
 155             return $grouping;
 156         }
 157     }
 158     return false;
 159 }
 160
 161 /**
 162  * Get the group object
 163  *
 164  * @category group
 165  * @param int $groupid ID of the group.
 166  * @param string $fields (default is all fields)
 167  * @param int $strictness (IGNORE_MISSING - default)
 168  * @return stdGlass group object
 169  */
 170 function groups_get_group($groupid, $fields='*', $strictness=IGNORE_MISSING) {
 171     global $DB;
 172     return $DB->get_record('groups', array('id'=>$groupid), $fields, $strictness);
 173 }
 174
 175 /**
 176  * Get the grouping object
 177  *
 178  * @category group
 179  * @param int $groupingid ID of the group.
 180  * @param string $fields
 181  * @param int $strictness (IGNORE_MISSING - default)
 182  * @return stdClass group object
 183  */
 184 function groups_get_grouping($groupingid, $fields='*', $strictness=IGNORE_MISSING) {
 185     global $DB;
 186     return $DB->get_record('groupings', array('id'=>$groupingid), $fields, $strictness);
 187 }
 188
 189 /**
 190  * Gets array of all groups in a specified course.
 191  *
 192  * @category group
 193  * @param int $courseid The id of the course.
 194  * @param mixed $userid optional user id or array of ids, returns only groups of the user.
 195  * @param int $groupingid optional returns only groups in the specified grouping.
 196  * @param string $fields
 197  * @return array Returns an array of the group objects (userid field returned if array in $userid)
 198  */
 199 function groups_get_all_groups($courseid, $userid=0, $groupingid=0, $fields='g.*') {
 200     global $DB;
 201
 202     // We need to check that we each field in the fields list belongs to the group table and that it has not being
 203     // aliased. If its something else we need to avoid the cache and run the query as who knows whats going on.
 204     $knownfields = true;
 205     if ($fields !== 'g.*') {
 206         // Quickly check if the first field is no longer g.id as using the
 207         // cache will return an array indexed differently than when expect
 208         if (strpos($fields, 'g.*') !== 0 && strpos($fields, 'g.id') !== 0) {
 209             $knownfields = false;
 210         } else {
 211             $fieldbits = explode(',', $fields);
 212             foreach ($fieldbits as $bit) {
 213                 $bit = trim($bit);
 214                 if (strpos($bit, 'g.') !== 0 or stripos($bit, ' AS ') !== false) {
 215                     $knownfields = false;
 216                     break;
 217                 }
 218             }
 219         }
 220     }
 221
 222     if (empty($userid) && $knownfields) {
 223         // We can use the cache.
 224         $data = groups_get_course_data($courseid);
 225         if (empty($groupingid)) {
 226             // All groups.. Easy!
 227             $groups = $data->groups;
 228         } else {
 229             $groups = array();
 230             foreach ($data->mappings as $mapping) {
 231                 if ($mapping->groupingid != $groupingid) {
 232                     continue;
 233                 }
 234                 if (isset($data->groups[$mapping->groupid])) {
 235                     $groups[$mapping->groupid] = $data->groups[$mapping->groupid];
 236                 }
 237             }
 238         }
 239         // Yay! We could use the cache. One more query saved.
 240         return $groups;
 241     }
 242
 243
 244     if (empty($userid)) {
 245         $userfrom  = "";
 246         $userwhere = "";
 247         $params = array();
 248
 249     } else {
 250         list($usql, $params) = $DB->get_in_or_equal($userid);
 251         $userfrom  = ", {groups_members} gm";
 252         $userwhere = "AND g.id = gm.groupid AND gm.userid $usql";
 253     }
 254
 255     if (!empty($groupingid)) {
 256         $groupingfrom  = ", {groupings_groups} gg";
 257         $groupingwhere = "AND g.id = gg.groupid AND gg.groupingid = ?";
 258         $params[] = $groupingid;
 259     } else {
 260         $groupingfrom  = "";
 261         $groupingwhere = "";
 262     }
 263
 264     array_unshift($params, $courseid);
 265
 266     return $DB->get_records_sql("SELECT $fields
 267                                    FROM {groups} g $userfrom $groupingfrom
 268                                   WHERE g.courseid = ? $userwhere $groupingwhere
 269                                ORDER BY name ASC", $params);
 270 }
 271
 272
 273 /**
 274  * Gets array of all groups in current user.
 275  *
 276  * @since Moodle 2.5
 277  * @category group
 278  * @return array Returns an array of the group objects.
 279  */
 280 function groups_get_my_groups() {
 281     global $DB, $USER;
 282     return $DB->get_records_sql("SELECT *
 283                                    FROM {groups_members} gm
 284                                    JOIN {groups} g
 285                                     ON g.id = gm.groupid
 286                                   WHERE gm.userid = ?
 287                                    ORDER BY name ASC", array($USER->id));
 288 }
 289
 290 /**
 291  * Returns info about user's groups in course.
 292  *
 293  * @category group
 294  * @param int $courseid
 295  * @param int $userid $USER if not specified
 296  * @return array Array[groupingid][groupid] including grouping id 0 which means all groups
 297  */
 298 function groups_get_user_groups($courseid, $userid=0) {
 299     global $USER, $DB;
 300
 301     if (empty($userid)) {
 302         $userid = $USER->id;
 303     }
 304
 305     $sql = "SELECT g.id, gg.groupingid
 306               FROM {groups} g
 307                    JOIN {groups_members} gm   ON gm.groupid = g.id
 308               LEFT JOIN {groupings_groups} gg ON gg.groupid = g.id
 309              WHERE gm.userid = ? AND g.courseid = ?";
 310     $params = array($userid, $courseid);
 311
 312     $rs = $DB->get_recordset_sql($sql, $params);
 313
 314     if (!$rs->valid()) {
 315         $rs->close(); // Not going to iterate (but exit), close rs
 316         return array('0' => array());
 317     }
 318
 319     $result    = array();
 320     $allgroups = array();
 321
 322     foreach ($rs as $group) {
 323         $allgroups[$group->id] = $group->id;
 324         if (is_null($group->groupingid)) {
 325             continue;
 326         }
 327         if (!array_key_exists($group->groupingid, $result)) {
 328             $result[$group->groupingid] = array();
 329         }
 330         $result[$group->groupingid][$group->id] = $group->id;
 331     }
 332     $rs->close();
 333
 334     $result['0'] = array_keys($allgroups); // all groups
 335
 336     return $result;
 337 }
 338
 339 /**
 340  * Gets an array of all groupings in a specified course. This value is cached
 341  * for a single course (so you can call it repeatedly for the same course
 342  * without a performance penalty).
 343  *
 344  * @category group
 345  * @param int $courseid return all groupings from course with this courseid
 346  * @return array Returns an array of the grouping objects (empty if none)
 347  */
 348 function groups_get_all_groupings($courseid) {
 349     $data = groups_get_course_data($courseid);
 350     return $data->groupings;
 351 }
 352
 353 /**
 354  * Determines if the user is a member of the given group.
 355  *
 356  * If $userid is null, use the global object.
 357  *
 358  * @category group
 359  * @param int $groupid The group to check for membership.
 360  * @param int $userid The user to check against the group.
 361  * @return bool True if the user is a member, false otherwise.
 362  */
 363 function groups_is_member($groupid, $userid=null) {
 364     global $USER, $DB;
 365
 366     if (!$userid) {
 367         $userid = $USER->id;
 368     }
 369
 370     return $DB->record_exists('groups_members', array('groupid'=>$groupid, 'userid'=>$userid));
 371 }
 372
 373 /**
 374  * Determines if current or specified is member of any active group in activity
 375  *
 376  * @category group
 377  * @staticvar array $cache
 378  * @param stdClass|cm_info $cm course module object
 379  * @param int $userid id of user, null means $USER->id
 380  * @return bool true if user member of at least one group used in activity
 381  */
 382 function groups_has_membership($cm, $userid=null) {
 383     global $CFG, $USER, $DB;
 384
 385     static $cache = array();
 386
 387     if (empty($userid)) {
 388         $userid = $USER->id;
 389     }
 390
 391     $cachekey = $userid.'|'.$cm->course.'|'.$cm->groupingid;
 392     if (isset($cache[$cachekey])) {
 393         return($cache[$cachekey]);
 394     }
 395
 396     if ($cm->groupingid) {
 397         // find out if member of any group in selected activity grouping
 398         $sql = "SELECT 'x'
 399                   FROM {groups_members} gm, {groupings_groups} gg
 400                  WHERE gm.userid = ? AND gm.groupid = gg.groupid AND gg.groupingid = ?";
 401         $params = array($userid, $cm->groupingid);
 402
 403     } else {
 404         // no grouping used - check all groups in course
 405         $sql = "SELECT 'x'
 406                   FROM {groups_members} gm, {groups} g
 407                  WHERE gm.userid = ? AND gm.groupid = g.id AND g.courseid = ?";
 408         $params = array($userid, $cm->course);
 409     }
 410
 411     $cache[$cachekey] = $DB->record_exists_sql($sql, $params);
 412
 413     return $cache[$cachekey];
 414 }
 415
 416 /**
 417  * Returns the users in the specified group.
 418  *
 419  * @category group
 420  * @param int $groupid The groupid to get the users for
 421  * @param int $fields The fields to return
 422  * @param int $sort optional sorting of returned users
 423  * @return array|bool Returns an array of the users for the specified
 424  * group or false if no users or an error returned.
 425  */
 426 function groups_get_members($groupid, $fields='u.*', $sort='lastname ASC') {
 427     global $DB;
 428
 429     return $DB->get_records_sql("SELECT $fields
 430                                    FROM {user} u, {groups_members} gm
 431                                   WHERE u.id = gm.userid AND gm.groupid = ?
 432                                ORDER BY $sort", array($groupid));
 433 }
 434
 435
 436 /**
 437  * Returns the users in the specified grouping.
 438  *
 439  * @category group
 440  * @param int $groupingid The groupingid to get the users for
 441  * @param string $fields The fields to return
 442  * @param string $sort optional sorting of returned users
 443  * @return array|bool Returns an array of the users for the specified
 444  * group or false if no users or an error returned.
 445  */
 446 function groups_get_grouping_members($groupingid, $fields='u.*', $sort='lastname ASC') {
 447     global $DB;
 448
 449     return $DB->get_records_sql("SELECT $fields
 450                                    FROM {user} u
 451                                      INNER JOIN {groups_members} gm ON u.id = gm.userid
 452                                      INNER JOIN {groupings_groups} gg ON gm.groupid = gg.groupid
 453                                   WHERE  gg.groupingid = ?
 454                                ORDER BY $sort", array($groupingid));
 455 }
 456
 457 /**
 458  * Returns effective groupmode used in course
 459  *
 460  * @category group
 461  * @param stdClass $course course object.
 462  * @return int group mode
 463  */
 464 function groups_get_course_groupmode($course) {
 465     return $course->groupmode;
 466 }
 467
 468 /**
 469  * Returns effective groupmode used in activity, course setting
 470  * overrides activity setting if groupmodeforce enabled.
 471  *
 472  * If $cm is an instance of cm_info it is easier to use $cm->effectivegroupmode
 473  *
 474  * @category group
 475  * @param cm_info|stdClass $cm the course module object. Only the ->course and ->groupmode need to be set.
 476  * @param stdClass $course object optional course object to improve perf
 477  * @return int group mode
 478  */
 479 function groups_get_activity_groupmode($cm, $course=null) {
 480     if ($cm instanceof cm_info) {
 481         return $cm->effectivegroupmode;
 482     }
 483     if (isset($course->id) and $course->id == $cm->course) {
 484         //ok
 485     } else {
 486         // Get course object (reuse $COURSE if possible).
 487         $course = get_course($cm->course, false);
 488     }
 489
 490     return empty($course->groupmodeforce) ? $cm->groupmode : $course->groupmode;
 491 }
 492
 493 /**
 494  * Print group menu selector for course level.
 495  *
 496  * @category group
 497  * @param stdClass $course course object
 498  * @param mixed $urlroot return address. Accepts either a string or a moodle_url
 499  * @param bool $return return as string instead of printing
 500  * @return mixed void or string depending on $return param
 501  */
 502 function groups_print_course_menu($course, $urlroot, $return=false) {
 503     global $USER, $OUTPUT;
 504
 505     if (!$groupmode = $course->groupmode) {
 506         if ($return) {
 507             return '';
 508         } else {
 509             return;
 510         }
 511     }
 512
 513     $context = context_course::instance($course->id);
 514     $aag = has_capability('moodle/site:accessallgroups', $context);
 515
 516     $usergroups = array();
 517     if ($groupmode == VISIBLEGROUPS or $aag) {
 518         $allowedgroups = groups_get_all_groups($course->id, 0, $course->defaultgroupingid);
 519         // Get user's own groups and put to the top.
 520         $usergroups = groups_get_all_groups($course->id, $USER->id, $course->defaultgroupingid);
 521     } else {
 522         $allowedgroups = groups_get_all_groups($course->id, $USER->id, $course->defaultgroupingid);
 523     }
 524
 525     $activegroup = groups_get_course_group($course, true, $allowedgroups);
 526
 527     $groupsmenu = array();
 528     if (!$allowedgroups or $groupmode == VISIBLEGROUPS or $aag) {
 529         $groupsmenu[0] = get_string('allparticipants');
 530     }
 531
 532     $groupsmenu += groups_sort_menu_options($allowedgroups, $usergroups);
 533
 534     if ($groupmode == VISIBLEGROUPS) {
 535         $grouplabel = get_string('groupsvisible');
 536     } else {
 537         $grouplabel = get_string('groupsseparate');
 538     }
 539
 540     if ($aag and $course->defaultgroupingid) {
 541         if ($grouping = groups_get_grouping($course->defaultgroupingid)) {
 542             $grouplabel = $grouplabel . ' (' . format_string($grouping->name) . ')';
 543         }
 544     }
 545
 546     if (count($groupsmenu) == 1) {
 547         $groupname = reset($groupsmenu);
 548         $output = $grouplabel.': '.$groupname;
 549     } else {
 550         $select = new single_select(new moodle_url($urlroot), 'group', $groupsmenu, $activegroup, null, 'selectgroup');
 551         $select->label = $grouplabel;
 552         $output = $OUTPUT->render($select);
 553     }
 554
 555     $output = '<div class="groupselector">'.$output.'</div>';
 556
 557     if ($return) {
 558         return $output;
 559     } else {
 560         echo $output;
 561     }
 562 }
 563
 564 /**
 565  * Turn an array of groups into an array of menu options.
 566  * @param array $groups of group objects.
 567  * @return array groupid => formatted group name.
 568  */
 569 function groups_list_to_menu($groups) {
 570     $groupsmenu = array();
 571     foreach ($groups as $group) {
 572         $groupsmenu[$group->id] = format_string($group->name);
 573     }
 574     return $groupsmenu;
 575 }
 576
 577 /**
 578  * Takes user's allowed groups and own groups and formats for use in group selector menu
 579  * If user has allowed groups + own groups will add to an optgroup
 580  * Own groups are removed from allowed groups
 581  * @param array $allowedgroups All groups user is allowed to see
 582  * @param array $usergroups Groups user belongs to
 583  * @return array
 584  */
 585 function groups_sort_menu_options($allowedgroups, $usergroups) {
 586     $useroptions = array();
 587     if ($usergroups) {
 588         $useroptions = groups_list_to_menu($usergroups);
 589
 590         // Remove user groups from other groups list.
 591         foreach ($usergroups as $group) {
 592             unset($allowedgroups[$group->id]);
 593         }
 594     }
 595
 596     $allowedoptions = array();
 597     if ($allowedgroups) {
 598         $allowedoptions = groups_list_to_menu($allowedgroups);
 599     }
 600
 601     if ($useroptions && $allowedoptions) {
 602         return array(
 603             1 => array(get_string('mygroups', 'group') => $useroptions),
 604             2 => array(get_string('othergroups', 'group') => $allowedoptions)
 605         );
 606     } else if ($useroptions) {
 607         return $useroptions;
 608     } else {
 609         return $allowedoptions;
 610     }
 611 }
 612
 613 /**
 614  * Generates html to print menu selector for course level, listing all groups.
 615  * Note: This api does not do any group mode check use groups_print_course_menu() instead if you want proper checks.
 616  *
 617  * @param stdclass          $course  course object.
 618  * @param string|moodle_url $urlroot return address. Accepts either a string or a moodle_url.
 619  * @param bool              $update  set this to true to update current active group based on the group param.
 620  * @param int               $activegroup Change group active to this group if $update set to true.
 621  *
 622  * @return string html or void
 623  */
 624 function groups_allgroups_course_menu($course, $urlroot, $update = false, $activegroup = 0) {
 625     global $SESSION, $OUTPUT, $USER;
 626
 627     $groupmode = groups_get_course_groupmode($course);
 628     $context = context_course::instance($course->id);
 629     $groupsmenu = array();
 630
 631     if (has_capability('moodle/site:accessallgroups', $context)) {
 632         $groupsmenu[0] = get_string('allparticipants');
 633         $allowedgroups = groups_get_all_groups($course->id, 0, $course->defaultgroupingid);
 634     } else {
 635         $allowedgroups = groups_get_all_groups($course->id, $USER->id, $course->defaultgroupingid);
 636     }
 637
 638     $groupsmenu += groups_list_to_menu($allowedgroups);
 639
 640     if ($update) {
 641         // Init activegroup array if necessary.
 642         if (!isset($SESSION->activegroup)) {
 643             $SESSION->activegroup = array();
 644         }
 645         if (!isset($SESSION->activegroup[$course->id])) {
 646             $SESSION->activegroup[$course->id] = array(SEPARATEGROUPS => array(), VISIBLEGROUPS => array(), 'aag' => array());
 647         }
 648         if (empty($groupsmenu[$activegroup])) {
 649             $activegroup = key($groupsmenu); // Force set to one of accessible groups.
 650         }
 651         $SESSION->activegroup[$course->id][$groupmode][$course->defaultgroupingid] = $activegroup;
 652     }
 653
 654     $grouplabel = get_string('groups');
 655     if (count($groupsmenu) == 0) {
 656         return '';
 657     } else if (count($groupsmenu) == 1) {
 658         $groupname = reset($groupsmenu);
 659         $output = $grouplabel.': '.$groupname;
 660     } else {
 661         $select = new single_select(new moodle_url($urlroot), 'group', $groupsmenu, $activegroup, null, 'selectgroup');
 662         $select->label = $grouplabel;
 663         $output = $OUTPUT->render($select);
 664     }
 665
 666     return $output;
 667
 668 }
 669
 670 /**
 671  * Print group menu selector for activity.
 672  *
 673  * @category group
 674  * @param stdClass|cm_info $cm course module object
 675  * @param string|moodle_url $urlroot return address that users get to if they choose an option;
 676  *   should include any parameters needed, e.g. "$CFG->wwwroot/mod/forum/view.php?id=34"
 677  * @param bool $return return as string instead of printing
 678  * @param bool $hideallparticipants If true, this prevents the 'All participants'
 679  *   option from appearing in cases where it normally would. This is intended for
 680  *   use only by activities that cannot display all groups together. (Note that
 681  *   selecting this option does not prevent groups_get_activity_group from
 682  *   returning 0; it will still do that if the user has chosen 'all participants'
 683  *   in another activity, or not chosen anything.)
 684  * @return mixed void or string depending on $return param
 685  */
 686 function groups_print_activity_menu($cm, $urlroot, $return=false, $hideallparticipants=false) {
 687     global $USER, $OUTPUT;
 688
 689     if ($urlroot instanceof moodle_url) {
 690         // no changes necessary
 691
 692     } else {
 693         if (strpos($urlroot, 'http') !== 0) { // Will also work for https
 694             // Display error if urlroot is not absolute (this causes the non-JS version to break)
 695             debugging('groups_print_activity_menu requires absolute URL for ' .
 696                       '$urlroot, not <tt>' . s($urlroot) . '</tt>. Example: ' .
 697                       'groups_print_activity_menu($cm, $CFG->wwwroot . \'/mod/mymodule/view.php?id=13\');',
 698                       DEBUG_DEVELOPER);
 699         }
 700         $urlroot = new moodle_url($urlroot);
 701     }
 702
 703     if (!$groupmode = groups_get_activity_groupmode($cm)) {
 704         if ($return) {
 705             return '';
 706         } else {
 707             return;
 708         }
 709     }
 710
 711     $context = context_module::instance($cm->id);
 712     $aag = has_capability('moodle/site:accessallgroups', $context);
 713
 714     $usergroups = array();
 715     if ($groupmode == VISIBLEGROUPS or $aag) {
 716         $allowedgroups = groups_get_all_groups($cm->course, 0, $cm->groupingid); // any group in grouping
 717         // Get user's own groups and put to the top.
 718         $usergroups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid);
 719     } else {
 720         $allowedgroups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid); // only assigned groups
 721     }
 722
 723     $activegroup = groups_get_activity_group($cm, true, $allowedgroups);
 724
 725     $groupsmenu = array();
 726     if ((!$allowedgroups or $groupmode == VISIBLEGROUPS or $aag) and !$hideallparticipants) {
 727         $groupsmenu[0] = get_string('allparticipants');
 728     }
 729
 730     $groupsmenu += groups_sort_menu_options($allowedgroups, $usergroups);
 731
 732     if ($groupmode == VISIBLEGROUPS) {
 733         $grouplabel = get_string('groupsvisible');
 734     } else {
 735         $grouplabel = get_string('groupsseparate');
 736     }
 737
 738     if ($aag and $cm->groupingid) {
 739         if ($grouping = groups_get_grouping($cm->groupingid)) {
 740             $grouplabel = $grouplabel . ' (' . format_string($grouping->name) . ')';
 741         }
 742     }
 743
 744     if (count($groupsmenu) == 1) {
 745         $groupname = reset($groupsmenu);
 746         $output = $grouplabel.': '.$groupname;
 747     } else {
 748         $select = new single_select($urlroot, 'group', $groupsmenu, $activegroup, null, 'selectgroup');
 749         $select->label = $grouplabel;
 750         $output = $OUTPUT->render($select);
 751     }
 752
 753     $output = '<div class="groupselector">'.$output.'</div>';
 754
 755     if ($return) {
 756         return $output;
 757     } else {
 758         echo $output;
 759     }
 760 }
 761
 762 /**
 763  * Returns group active in course, changes the group by default if 'group' page param present
 764  *
 765  * @category group
 766  * @param stdClass $course course bject
 767  * @param bool $update change active group if group param submitted
 768  * @param array $allowedgroups list of groups user may access (INTERNAL, to be used only from groups_print_course_menu())
 769  * @return mixed false if groups not used, int if groups used, 0 means all groups (access must be verified in SEPARATE mode)
 770  */
 771 function groups_get_course_group($course, $update=false, $allowedgroups=null) {
 772     global $USER, $SESSION;
 773
 774     if (!$groupmode = $course->groupmode) {
 775         // NOGROUPS used
 776         return false;
 777     }
 778
 779     $context = context_course::instance($course->id);
 780     if (has_capability('moodle/site:accessallgroups', $context)) {
 781         $groupmode = 'aag';
 782     }
 783
 784     if (!is_array($allowedgroups)) {
 785         if ($groupmode == VISIBLEGROUPS or $groupmode === 'aag') {
 786             $allowedgroups = groups_get_all_groups($course->id, 0, $course->defaultgroupingid);
 787         } else {
 788             $allowedgroups = groups_get_all_groups($course->id, $USER->id, $course->defaultgroupingid);
 789         }
 790     }
 791
 792     _group_verify_activegroup($course->id, $groupmode, $course->defaultgroupingid, $allowedgroups);
 793
 794     // set new active group if requested
 795     $changegroup = optional_param('group', -1, PARAM_INT);
 796     if ($update and $changegroup != -1) {
 797
 798         if ($changegroup == 0) {
 799             // do not allow changing to all groups without accessallgroups capability
 800             if ($groupmode == VISIBLEGROUPS or $groupmode === 'aag') {
 801                 $SESSION->activegroup[$course->id][$groupmode][$course->defaultgroupingid] = 0;
 802             }
 803
 804         } else {
 805             if ($allowedgroups and array_key_exists($changegroup, $allowedgroups)) {
 806                 $SESSION->activegroup[$course->id][$groupmode][$course->defaultgroupingid] = $changegroup;
 807             }
 808         }
 809     }
 810
 811     return $SESSION->activegroup[$course->id][$groupmode][$course->defaultgroupingid];
 812 }
 813
 814 /**
 815  * Returns group active in activity, changes the group by default if 'group' page param present
 816  *
 817  * @category group
 818  * @param stdClass|cm_info $cm course module object
 819  * @param bool $update change active group if group param submitted
 820  * @param array $allowedgroups list of groups user may access (INTERNAL, to be used only from groups_print_activity_menu())
 821  * @return mixed false if groups not used, int if groups used, 0 means all groups (access must be verified in SEPARATE mode)
 822  */
 823 function groups_get_activity_group($cm, $update=false, $allowedgroups=null) {
 824     global $USER, $SESSION;
 825
 826     if (!$groupmode = groups_get_activity_groupmode($cm)) {
 827         // NOGROUPS used
 828         return false;
 829     }
 830
 831     $context = context_module::instance($cm->id);
 832     if (has_capability('moodle/site:accessallgroups', $context)) {
 833         $groupmode = 'aag';
 834     }
 835
 836     if (!is_array($allowedgroups)) {
 837         if ($groupmode == VISIBLEGROUPS or $groupmode === 'aag') {
 838             $allowedgroups = groups_get_all_groups($cm->course, 0, $cm->groupingid);
 839         } else {
 840             $allowedgroups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid);
 841         }
 842     }
 843
 844     _group_verify_activegroup($cm->course, $groupmode, $cm->groupingid, $allowedgroups);
 845
 846     // set new active group if requested
 847     $changegroup = optional_param('group', -1, PARAM_INT);
 848     if ($update and $changegroup != -1) {
 849
 850         if ($changegroup == 0) {
 851             // allgroups visible only in VISIBLEGROUPS or when accessallgroups
 852             if ($groupmode == VISIBLEGROUPS or $groupmode === 'aag') {
 853                 $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid] = 0;
 854             }
 855
 856         } else {
 857             if ($allowedgroups and array_key_exists($changegroup, $allowedgroups)) {
 858                 $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid] = $changegroup;
 859             }
 860         }
 861     }
 862
 863     return $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid];
 864 }
 865
 866 /**
 867  * Gets a list of groups that the user is allowed to access within the
 868  * specified activity.
 869  *
 870  * @category group
 871  * @param stdClass|cm_info $cm Course-module
 872  * @param int $userid User ID (defaults to current user)
 873  * @return array An array of group objects, or false if none
 874  */
 875 function groups_get_activity_allowed_groups($cm,$userid=0) {
 876     // Use current user by default
 877     global $USER;
 878     if(!$userid) {
 879         $userid=$USER->id;
 880     }
 881
 882     // Get groupmode for activity, taking into account course settings
 883     $groupmode=groups_get_activity_groupmode($cm);
 884
 885     // If visible groups mode, or user has the accessallgroups capability,
 886     // then they can access all groups for the activity...
 887     $context = context_module::instance($cm->id);
 888     if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $context, $userid)) {
 889         return groups_get_all_groups($cm->course, 0, $cm->groupingid);
 890     } else {
 891         // ...otherwise they can only access groups they belong to
 892         return groups_get_all_groups($cm->course, $userid, $cm->groupingid);
 893     }
 894 }
 895
 896 /**
 897  * Determine if a given group is visible to user or not in a given context.
 898  *
 899  * @since Moodle 2.6
 900  * @param int      $groupid Group id to test. 0 for all groups.
 901  * @param stdClass $course  Course object.
 902  * @param stdClass $cm      Course module object.
 903  * @param int      $userid  user id to test against. Defaults to $USER.
 904  * @return boolean true if visible, false otherwise
 905  */
 906 function groups_group_visible($groupid, $course, $cm = null, $userid = null) {
 907     global $USER;
 908
 909     if (empty($userid)) {
 910         $userid = $USER->id;
 911     }
 912
 913     $groupmode = empty($cm) ? groups_get_course_groupmode($course) : groups_get_activity_groupmode($cm, $course);
 914     if ($groupmode == NOGROUPS || $groupmode == VISIBLEGROUPS) {
 915         // Groups are not used, or everything is visible, no need to go any further.
 916         return true;
 917     }
 918
 919     $context = empty($cm) ? context_course::instance($course->id) : context_module::instance($cm->id);
 920     if (has_capability('moodle/site:accessallgroups', $context, $userid)) {
 921         // User can see everything. Groupid = 0 is handled here as well.
 922         return true;
 923     } else if ($groupid != 0) {
 924         // Group mode is separate, and user doesn't have access all groups capability. Check if user can see requested group.
 925         $groups = empty($cm) ? groups_get_all_groups($course->id, $userid) : groups_get_activity_allowed_groups($cm, $userid);
 926         if (array_key_exists($groupid, $groups)) {
 927             // User can see the group.
 928             return true;
 929         }
 930     }
 931     return false;
 932 }
 933
 934 /**
 935  * Internal method, sets up $SESSION->activegroup and verifies previous value
 936  *
 937  * @param int $courseid
 938  * @param int|string $groupmode SEPARATEGROUPS, VISIBLEGROUPS or 'aag' (access all groups)
 939  * @param int $groupingid 0 means all groups
 940  * @param array $allowedgroups list of groups user can see
 941  */
 942 function _group_verify_activegroup($courseid, $groupmode, $groupingid, array $allowedgroups) {
 943     global $SESSION, $USER;
 944
 945     // init activegroup array if necessary
 946     if (!isset($SESSION->activegroup)) {
 947         $SESSION->activegroup = array();
 948     }
 949     if (!array_key_exists($courseid, $SESSION->activegroup)) {
 950         $SESSION->activegroup[$courseid] = array(SEPARATEGROUPS=>array(), VISIBLEGROUPS=>array(), 'aag'=>array());
 951     }
 952
 953     // make sure that the current group info is ok
 954     if (array_key_exists($groupingid, $SESSION->activegroup[$courseid][$groupmode]) and !array_key_exists($SESSION->activegroup[$courseid][$groupmode][$groupingid], $allowedgroups)) {
 955         // active group does not exist anymore or is 0
 956         if ($SESSION->activegroup[$courseid][$groupmode][$groupingid] > 0 or $groupmode == SEPARATEGROUPS) {
 957             // do not do this if all groups selected and groupmode is not separate
 958             unset($SESSION->activegroup[$courseid][$groupmode][$groupingid]);
 959         }
 960     }
 961
 962     // set up defaults if necessary
 963     if (!array_key_exists($groupingid, $SESSION->activegroup[$courseid][$groupmode])) {
 964         if ($groupmode == 'aag') {
 965             $SESSION->activegroup[$courseid][$groupmode][$groupingid] = 0; // all groups by default if user has accessallgroups
 966
 967         } else if ($allowedgroups) {
 968             if ($groupmode != SEPARATEGROUPS and $mygroups = groups_get_all_groups($courseid, $USER->id, $groupingid)) {
 969                 $firstgroup = reset($mygroups);
 970             } else {
 971                 $firstgroup = reset($allowedgroups);
 972             }
 973             $SESSION->activegroup[$courseid][$groupmode][$groupingid] = $firstgroup->id;
 974
 975         } else {
 976             // this happen when user not assigned into group in SEPARATEGROUPS mode or groups do not exist yet
 977             // mod authors must add extra checks for this when SEPARATEGROUPS mode used (such as when posting to forum)
 978             $SESSION->activegroup[$courseid][$groupmode][$groupingid] = 0;
 979         }
 980     }
 981 }
 982
 983 /**
 984  * Caches group data for a particular course to speed up subsequent requests.
 985  *
 986  * @param int $courseid The course id to cache data for.
 987  * @param cache $cache The cache if it has already been initialised. If not a new one will be created.
 988  * @return stdClass A data object containing groups, groupings, and mappings.
 989  */
 990 function groups_cache_groupdata($courseid, cache $cache = null) {
 991     global $DB;
 992
 993     if ($cache === null) {
 994         // Initialise a cache if we wern't given one.
 995         $cache = cache::make('core', 'groupdata');
 996     }
 997
 998     // Get the groups that belong to the course.
 999     $groups = $DB->get_records('groups', array('courseid' => $courseid), 'name ASC');
1000     // Get the groupings that belong to the course.
1001     $groupings = $DB->get_records('groupings', array('courseid' => $courseid), 'name ASC');
1002
1003     if (!is_array($groups)) {
1004         $groups = array();
1005     }
1006
1007     if (!is_array($groupings)) {
1008         $groupings = array();
1009     }
1010
1011     if (!empty($groupings)) {
1012         // Finally get the mappings between the two.
1013         list($insql, $params) = $DB->get_in_or_equal(array_keys($groupings));
1014         $mappings = $DB->get_records_sql("
1015                 SELECT gg.id, gg.groupingid, gg.groupid
1016                   FROM {groupings_groups} gg
1017                   JOIN {groups} g ON g.id = gg.groupid
1018                  WHERE gg.groupingid $insql
1019               ORDER BY g.name ASC", $params);
1020     } else {
1021         $mappings = array();
1022     }
1023
1024     // Prepare the data array.
1025     $data = new stdClass;
1026     $data->groups = $groups;
1027     $data->groupings = $groupings;
1028     $data->mappings = $mappings;
1029     // Cache the data.
1030     $cache->set($courseid, $data);
1031     // Finally return it so it can be used if desired.
1032     return $data;
1033 }
1034
1035 /**
1036  * Gets group data for a course.
1037  *
1038  * This returns an object with the following properties:
1039  *   - groups : An array of all the groups in the course.
1040  *   - groupings : An array of all the groupings within the course.
1041  *   - mappings : An array of group to grouping mappings.
1042  *
1043  * @param int $courseid The course id to get data for.
1044  * @param cache $cache The cache if it has already been initialised. If not a new one will be created.
1045  * @return stdClass
1046  */
1047 function groups_get_course_data($courseid, cache $cache = null) {
1048     if ($cache === null) {
1049         // Initialise a cache if we wern't given one.
1050         $cache = cache::make('core', 'groupdata');
1051     }
1052     // Try to retrieve it from the cache.
1053     $data = $cache->get($courseid);
1054     if ($data === false) {
1055         $data = groups_cache_groupdata($courseid, $cache);
1056     }
1057     return $data;
1058 }
1059
1060 /**
1061  * Determine if the current user can see at least one of the groups of the specified user.
1062  *
1063  * @param stdClass $course  Course object.
1064  * @param int $userid  user id to check against.
1065  * @param stdClass $cm Course module object. Optional, just for checking at activity level instead course one.
1066  * @return boolean true if visible, false otherwise
1067  * @since Moodle 2.9
1068  */
1069 function groups_user_groups_visible($course, $userid, $cm = null) {
1070     global $USER;
1071
1072     $groupmode = empty($cm) ? groups_get_course_groupmode($course) : groups_get_activity_groupmode($cm, $course);
1073     if ($groupmode == NOGROUPS || $groupmode == VISIBLEGROUPS) {
1074         // Groups are not used, or everything is visible, no need to go any further.
1075         return true;
1076     }
1077
1078     $context = empty($cm) ? context_course::instance($course->id) : context_module::instance($cm->id);
1079     if (has_capability('moodle/site:accessallgroups', $context)) {
1080         // User can see everything.
1081         return true;
1082     } else {
1083         // Group mode is separate, and user doesn't have access all groups capability.
1084         if (empty($cm)) {
1085             $usergroups = groups_get_all_groups($course->id, $userid);
1086             $currentusergroups = groups_get_all_groups($course->id, $USER->id);
1087         } else {
1088             $usergroups = groups_get_activity_allowed_groups($cm, $userid);
1089             $currentusergroups = groups_get_activity_allowed_groups($cm, $USER->id);
1090         }
1091
1092         $samegroups = array_intersect_key($currentusergroups, $usergroups);
1093         if (!empty($samegroups)) {
1094             // We share groups!
1095             return true;
1096         }
1097     }
1098     return false;
1099 }