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         $fieldbits = explode(',', $fields);
 207         foreach ($fieldbits as $bit) {
 208             $bit = trim($bit);
 209             if (strpos($bit, 'g.') !== 0 or stripos($bit, ' AS ') !== false) {
 210                 $knownfields = false;
 211                 break;
 212             }
 213         }
 214     }
 215
 216     if (empty($userid) && $knownfields) {
 217         // We can use the cache.
 218         $data = groups_get_course_data($courseid);
 219         if (empty($groupingid)) {
 220             // All groups.. Easy!
 221             $groups = $data->groups;
 222         } else {
 223             $groups = array();
 224             foreach ($data->mappings as $mapping) {
 225                 if ($mapping->groupingid != $groupingid) {
 226                     continue;
 227                 }
 228                 if (isset($data->groups[$mapping->groupid])) {
 229                     $groups[$mapping->groupid] = $data->groups[$mapping->groupid];
 230                 }
 231             }
 232         }
 233         // Yay! We could use the cache. One more query saved.
 234         return $groups;
 235     }
 236
 237
 238     if (empty($userid)) {
 239         $userfrom  = "";
 240         $userwhere = "";
 241         $params = array();
 242
 243     } else {
 244         list($usql, $params) = $DB->get_in_or_equal($userid);
 245         $userfrom  = ", {groups_members} gm";
 246         $userwhere = "AND g.id = gm.groupid AND gm.userid $usql";
 247     }
 248
 249     if (!empty($groupingid)) {
 250         $groupingfrom  = ", {groupings_groups} gg";
 251         $groupingwhere = "AND g.id = gg.groupid AND gg.groupingid = ?";
 252         $params[] = $groupingid;
 253     } else {
 254         $groupingfrom  = "";
 255         $groupingwhere = "";
 256     }
 257
 258     array_unshift($params, $courseid);
 259
 260     return $DB->get_records_sql("SELECT $fields
 261                                    FROM {groups} g $userfrom $groupingfrom
 262                                   WHERE g.courseid = ? $userwhere $groupingwhere
 263                                ORDER BY name ASC", $params);
 264 }
 265
 266
 267 /**
 268  * Gets array of all groups in current user.
 269  *
 270  * @since Moodle 2.5
 271  * @category group
 272  * @return array Returns an array of the group objects.
 273  */
 274 function groups_get_my_groups() {
 275     global $DB, $USER;
 276     return $DB->get_records_sql("SELECT *
 277                                    FROM {groups_members} gm
 278                                    JOIN {groups} g
 279                                     ON g.id = gm.groupid
 280                                   WHERE gm.userid = ?
 281                                    ORDER BY name ASC", array($USER->id));
 282 }
 283
 284 /**
 285  * Returns info about user's groups in course.
 286  *
 287  * @category group
 288  * @param int $courseid
 289  * @param int $userid $USER if not specified
 290  * @return array Array[groupingid][groupid] including grouping id 0 which means all groups
 291  */
 292 function groups_get_user_groups($courseid, $userid=0) {
 293     global $USER, $DB;
 294
 295     if (empty($userid)) {
 296         $userid = $USER->id;
 297     }
 298
 299     $sql = "SELECT g.id, gg.groupingid
 300               FROM {groups} g
 301                    JOIN {groups_members} gm   ON gm.groupid = g.id
 302               LEFT JOIN {groupings_groups} gg ON gg.groupid = g.id
 303              WHERE gm.userid = ? AND g.courseid = ?";
 304     $params = array($userid, $courseid);
 305
 306     $rs = $DB->get_recordset_sql($sql, $params);
 307
 308     if (!$rs->valid()) {
 309         $rs->close(); // Not going to iterate (but exit), close rs
 310         return array('0' => array());
 311     }
 312
 313     $result    = array();
 314     $allgroups = array();
 315
 316     foreach ($rs as $group) {
 317         $allgroups[$group->id] = $group->id;
 318         if (is_null($group->groupingid)) {
 319             continue;
 320         }
 321         if (!array_key_exists($group->groupingid, $result)) {
 322             $result[$group->groupingid] = array();
 323         }
 324         $result[$group->groupingid][$group->id] = $group->id;
 325     }
 326     $rs->close();
 327
 328     $result['0'] = array_keys($allgroups); // all groups
 329
 330     return $result;
 331 }
 332
 333 /**
 334  * Gets an array of all groupings in a specified course. This value is cached
 335  * for a single course (so you can call it repeatedly for the same course
 336  * without a performance penalty).
 337  *
 338  * @category group
 339  * @param int $courseid return all groupings from course with this courseid
 340  * @return array Returns an array of the grouping objects (empty if none)
 341  */
 342 function groups_get_all_groupings($courseid) {
 343     $data = groups_get_course_data($courseid);
 344     return $data->groupings;
 345 }
 346
 347 /**
 348  * Determines if the user is a member of the given group.
 349  *
 350  * If $userid is null, use the global object.
 351  *
 352  * @category group
 353  * @param int $groupid The group to check for membership.
 354  * @param int $userid The user to check against the group.
 355  * @return bool True if the user is a member, false otherwise.
 356  */
 357 function groups_is_member($groupid, $userid=null) {
 358     global $USER, $DB;
 359
 360     if (!$userid) {
 361         $userid = $USER->id;
 362     }
 363
 364     return $DB->record_exists('groups_members', array('groupid'=>$groupid, 'userid'=>$userid));
 365 }
 366
 367 /**
 368  * Determines if current or specified is member of any active group in activity
 369  *
 370  * @category group
 371  * @staticvar array $cache
 372  * @param cm_info $cm course module object
 373  * @param int $userid id of user, null means $USER->id
 374  * @return bool true if user member of at least one group used in activity
 375  */
 376 function groups_has_membership($cm, $userid=null) {
 377     global $CFG, $USER, $DB;
 378
 379     static $cache = array();
 380
 381     if (empty($userid)) {
 382         $userid = $USER->id;
 383     }
 384
 385     $cachekey = $userid.'|'.$cm->course.'|'.$cm->groupingid;
 386     if (isset($cache[$cachekey])) {
 387         return($cache[$cachekey]);
 388     }
 389
 390     if ($cm->groupingid) {
 391         // find out if member of any group in selected activity grouping
 392         $sql = "SELECT 'x'
 393                   FROM {groups_members} gm, {groupings_groups} gg
 394                  WHERE gm.userid = ? AND gm.groupid = gg.groupid AND gg.groupingid = ?";
 395         $params = array($userid, $cm->groupingid);
 396
 397     } else {
 398         // no grouping used - check all groups in course
 399         $sql = "SELECT 'x'
 400                   FROM {groups_members} gm, {groups} g
 401                  WHERE gm.userid = ? AND gm.groupid = g.id AND g.courseid = ?";
 402         $params = array($userid, $cm->course);
 403     }
 404
 405     $cache[$cachekey] = $DB->record_exists_sql($sql, $params);
 406
 407     return $cache[$cachekey];
 408 }
 409
 410 /**
 411  * Returns the users in the specified group.
 412  *
 413  * @category group
 414  * @param int $groupid The groupid to get the users for
 415  * @param int $fields The fields to return
 416  * @param int $sort optional sorting of returned users
 417  * @return array|bool Returns an array of the users for the specified
 418  * group or false if no users or an error returned.
 419  */
 420 function groups_get_members($groupid, $fields='u.*', $sort='lastname ASC') {
 421     global $DB;
 422
 423     return $DB->get_records_sql("SELECT $fields
 424                                    FROM {user} u, {groups_members} gm
 425                                   WHERE u.id = gm.userid AND gm.groupid = ?
 426                                ORDER BY $sort", array($groupid));
 427 }
 428
 429
 430 /**
 431  * Returns the users in the specified grouping.
 432  *
 433  * @category group
 434  * @param int $groupingid The groupingid to get the users for
 435  * @param string $fields The fields to return
 436  * @param string $sort optional sorting of returned users
 437  * @return array|bool Returns an array of the users for the specified
 438  * group or false if no users or an error returned.
 439  */
 440 function groups_get_grouping_members($groupingid, $fields='u.*', $sort='lastname ASC') {
 441     global $DB;
 442
 443     return $DB->get_records_sql("SELECT $fields
 444                                    FROM {user} u
 445                                      INNER JOIN {groups_members} gm ON u.id = gm.userid
 446                                      INNER JOIN {groupings_groups} gg ON gm.groupid = gg.groupid
 447                                   WHERE  gg.groupingid = ?
 448                                ORDER BY $sort", array($groupingid));
 449 }
 450
 451 /**
 452  * Returns effective groupmode used in course
 453  *
 454  * @category group
 455  * @param stdClass $course course object.
 456  * @return int group mode
 457  */
 458 function groups_get_course_groupmode($course) {
 459     return $course->groupmode;
 460 }
 461
 462 /**
 463  * Returns effective groupmode used in activity, course setting
 464  * overrides activity setting if groupmodeforce enabled.
 465  *
 466  * @category group
 467  * @param cm_info $cm the course module object. Only the ->course and ->groupmode need to be set.
 468  * @param stdClass $course object optional course object to improve perf
 469  * @return int group mode
 470  */
 471 function groups_get_activity_groupmode($cm, $course=null) {
 472     global $COURSE, $DB;
 473
 474     // get course object (reuse COURSE if possible)
 475     if (isset($course->id) and $course->id == $cm->course) {
 476         //ok
 477     } else if ($cm->course == $COURSE->id) {
 478         $course = $COURSE;
 479     } else {
 480         if (!$course = $DB->get_record('course', array('id'=>$cm->course))) {
 481             print_error('invalidcourseid');
 482         }
 483     }
 484
 485     return empty($course->groupmodeforce) ? $cm->groupmode : $course->groupmode;
 486 }
 487
 488 /**
 489  * Print group menu selector for course level.
 490  *
 491  * @category group
 492  * @param stdClass $course course object
 493  * @param mixed $urlroot return address. Accepts either a string or a moodle_url
 494  * @param bool $return return as string instead of printing
 495  * @return mixed void or string depending on $return param
 496  */
 497 function groups_print_course_menu($course, $urlroot, $return=false) {
 498     global $USER, $OUTPUT;
 499
 500     if (!$groupmode = $course->groupmode) {
 501         if ($return) {
 502             return '';
 503         } else {
 504             return;
 505         }
 506     }
 507
 508     $context = context_course::instance($course->id);
 509     $aag = has_capability('moodle/site:accessallgroups', $context);
 510
 511     if ($groupmode == VISIBLEGROUPS or $aag) {
 512         $allowedgroups = groups_get_all_groups($course->id, 0, $course->defaultgroupingid);
 513     } else {
 514         $allowedgroups = groups_get_all_groups($course->id, $USER->id, $course->defaultgroupingid);
 515     }
 516
 517     $activegroup = groups_get_course_group($course, true, $allowedgroups);
 518
 519     $groupsmenu = array();
 520     if (!$allowedgroups or $groupmode == VISIBLEGROUPS or $aag) {
 521         $groupsmenu[0] = get_string('allparticipants');
 522     }
 523
 524     if ($allowedgroups) {
 525         foreach ($allowedgroups as $group) {
 526             $groupsmenu[$group->id] = format_string($group->name);
 527         }
 528     }
 529
 530     if ($groupmode == VISIBLEGROUPS) {
 531         $grouplabel = get_string('groupsvisible');
 532     } else {
 533         $grouplabel = get_string('groupsseparate');
 534     }
 535
 536     if ($aag and $course->defaultgroupingid) {
 537         if ($grouping = groups_get_grouping($course->defaultgroupingid)) {
 538             $grouplabel = $grouplabel . ' (' . format_string($grouping->name) . ')';
 539         }
 540     }
 541
 542     if (count($groupsmenu) == 1) {
 543         $groupname = reset($groupsmenu);
 544         $output = $grouplabel.': '.$groupname;
 545     } else {
 546         $select = new single_select(new moodle_url($urlroot), 'group', $groupsmenu, $activegroup, null, 'selectgroup');
 547         $select->label = $grouplabel;
 548         $output = $OUTPUT->render($select);
 549     }
 550
 551     $output = '<div class="groupselector">'.$output.'</div>';
 552
 553     if ($return) {
 554         return $output;
 555     } else {
 556         echo $output;
 557     }
 558 }
 559
 560 /**
 561  * Print group menu selector for activity.
 562  *
 563  * @category group
 564  * @param stdClass $cm course module object
 565  * @param string|moodle_url $urlroot return address that users get to if they choose an option;
 566  *   should include any parameters needed, e.g. "$CFG->wwwroot/mod/forum/view.php?id=34"
 567  * @param bool $return return as string instead of printing
 568  * @param bool $hideallparticipants If true, this prevents the 'All participants'
 569  *   option from appearing in cases where it normally would. This is intended for
 570  *   use only by activities that cannot display all groups together. (Note that
 571  *   selecting this option does not prevent groups_get_activity_group from
 572  *   returning 0; it will still do that if the user has chosen 'all participants'
 573  *   in another activity, or not chosen anything.)
 574  * @return mixed void or string depending on $return param
 575  */
 576 function groups_print_activity_menu($cm, $urlroot, $return=false, $hideallparticipants=false) {
 577     global $USER, $OUTPUT;
 578
 579     if ($urlroot instanceof moodle_url) {
 580         // no changes necessary
 581
 582     } else {
 583         if (strpos($urlroot, 'http') !== 0) { // Will also work for https
 584             // Display error if urlroot is not absolute (this causes the non-JS version to break)
 585             debugging('groups_print_activity_menu requires absolute URL for ' .
 586                       '$urlroot, not <tt>' . s($urlroot) . '</tt>. Example: ' .
 587                       'groups_print_activity_menu($cm, $CFG->wwwroot . \'/mod/mymodule/view.php?id=13\');',
 588                       DEBUG_DEVELOPER);
 589         }
 590         $urlroot = new moodle_url($urlroot);
 591     }
 592
 593     if (!$groupmode = groups_get_activity_groupmode($cm)) {
 594         if ($return) {
 595             return '';
 596         } else {
 597             return;
 598         }
 599     }
 600
 601     $context = context_module::instance($cm->id);
 602     $aag = has_capability('moodle/site:accessallgroups', $context);
 603
 604     if ($groupmode == VISIBLEGROUPS or $aag) {
 605         $allowedgroups = groups_get_all_groups($cm->course, 0, $cm->groupingid); // any group in grouping
 606     } else {
 607         $allowedgroups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid); // only assigned groups
 608     }
 609
 610     $activegroup = groups_get_activity_group($cm, true, $allowedgroups);
 611
 612     $groupsmenu = array();
 613     if ((!$allowedgroups or $groupmode == VISIBLEGROUPS or $aag) and !$hideallparticipants) {
 614         $groupsmenu[0] = get_string('allparticipants');
 615     }
 616
 617     if ($allowedgroups) {
 618         foreach ($allowedgroups as $group) {
 619             $groupsmenu[$group->id] = format_string($group->name);
 620         }
 621     }
 622
 623     if ($groupmode == VISIBLEGROUPS) {
 624         $grouplabel = get_string('groupsvisible');
 625     } else {
 626         $grouplabel = get_string('groupsseparate');
 627     }
 628
 629     if ($aag and $cm->groupingid) {
 630         if ($grouping = groups_get_grouping($cm->groupingid)) {
 631             $grouplabel = $grouplabel . ' (' . format_string($grouping->name) . ')';
 632         }
 633     }
 634
 635     if (count($groupsmenu) == 1) {
 636         $groupname = reset($groupsmenu);
 637         $output = $grouplabel.': '.$groupname;
 638     } else {
 639         $select = new single_select($urlroot, 'group', $groupsmenu, $activegroup, null, 'selectgroup');
 640         $select->label = $grouplabel;
 641         $output = $OUTPUT->render($select);
 642     }
 643
 644     $output = '<div class="groupselector">'.$output.'</div>';
 645
 646     if ($return) {
 647         return $output;
 648     } else {
 649         echo $output;
 650     }
 651 }
 652
 653 /**
 654  * Returns group active in course, changes the group by default if 'group' page param present
 655  *
 656  * @category group
 657  * @param stdClass $course course bject
 658  * @param bool $update change active group if group param submitted
 659  * @param array $allowedgroups list of groups user may access (INTERNAL, to be used only from groups_print_course_menu())
 660  * @return mixed false if groups not used, int if groups used, 0 means all groups (access must be verified in SEPARATE mode)
 661  */
 662 function groups_get_course_group($course, $update=false, $allowedgroups=null) {
 663     global $USER, $SESSION;
 664
 665     if (!$groupmode = $course->groupmode) {
 666         // NOGROUPS used
 667         return false;
 668     }
 669
 670     $context = context_course::instance($course->id);
 671     if (has_capability('moodle/site:accessallgroups', $context)) {
 672         $groupmode = 'aag';
 673     }
 674
 675     if (!is_array($allowedgroups)) {
 676         if ($groupmode == VISIBLEGROUPS or $groupmode === 'aag') {
 677             $allowedgroups = groups_get_all_groups($course->id, 0, $course->defaultgroupingid);
 678         } else {
 679             $allowedgroups = groups_get_all_groups($course->id, $USER->id, $course->defaultgroupingid);
 680         }
 681     }
 682
 683     _group_verify_activegroup($course->id, $groupmode, $course->defaultgroupingid, $allowedgroups);
 684
 685     // set new active group if requested
 686     $changegroup = optional_param('group', -1, PARAM_INT);
 687     if ($update and $changegroup != -1) {
 688
 689         if ($changegroup == 0) {
 690             // do not allow changing to all groups without accessallgroups capability
 691             if ($groupmode == VISIBLEGROUPS or $groupmode === 'aag') {
 692                 $SESSION->activegroup[$course->id][$groupmode][$course->defaultgroupingid] = 0;
 693             }
 694
 695         } else {
 696             if ($allowedgroups and array_key_exists($changegroup, $allowedgroups)) {
 697                 $SESSION->activegroup[$course->id][$groupmode][$course->defaultgroupingid] = $changegroup;
 698             }
 699         }
 700     }
 701
 702     return $SESSION->activegroup[$course->id][$groupmode][$course->defaultgroupingid];
 703 }
 704
 705 /**
 706  * Returns group active in activity, changes the group by default if 'group' page param present
 707  *
 708  * @category group
 709  * @param stdClass $cm course module object
 710  * @param bool $update change active group if group param submitted
 711  * @param array $allowedgroups list of groups user may access (INTERNAL, to be used only from groups_print_activity_menu())
 712  * @return mixed false if groups not used, int if groups used, 0 means all groups (access must be verified in SEPARATE mode)
 713  */
 714 function groups_get_activity_group($cm, $update=false, $allowedgroups=null) {
 715     global $USER, $SESSION;
 716
 717     if (!$groupmode = groups_get_activity_groupmode($cm)) {
 718         // NOGROUPS used
 719         return false;
 720     }
 721
 722     $context = context_module::instance($cm->id);
 723     if (has_capability('moodle/site:accessallgroups', $context)) {
 724         $groupmode = 'aag';
 725     }
 726
 727     if (!is_array($allowedgroups)) {
 728         if ($groupmode == VISIBLEGROUPS or $groupmode === 'aag') {
 729             $allowedgroups = groups_get_all_groups($cm->course, 0, $cm->groupingid);
 730         } else {
 731             $allowedgroups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid);
 732         }
 733     }
 734
 735     _group_verify_activegroup($cm->course, $groupmode, $cm->groupingid, $allowedgroups);
 736
 737     // set new active group if requested
 738     $changegroup = optional_param('group', -1, PARAM_INT);
 739     if ($update and $changegroup != -1) {
 740
 741         if ($changegroup == 0) {
 742             // allgroups visible only in VISIBLEGROUPS or when accessallgroups
 743             if ($groupmode == VISIBLEGROUPS or $groupmode === 'aag') {
 744                 $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid] = 0;
 745             }
 746
 747         } else {
 748             if ($allowedgroups and array_key_exists($changegroup, $allowedgroups)) {
 749                 $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid] = $changegroup;
 750             }
 751         }
 752     }
 753
 754     return $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid];
 755 }
 756
 757 /**
 758  * Gets a list of groups that the user is allowed to access within the
 759  * specified activity.
 760  *
 761  * @category group
 762  * @param stdClass $cm Course-module
 763  * @param int $userid User ID (defaults to current user)
 764  * @return array An array of group objects, or false if none
 765  */
 766 function groups_get_activity_allowed_groups($cm,$userid=0) {
 767     // Use current user by default
 768     global $USER;
 769     if(!$userid) {
 770         $userid=$USER->id;
 771     }
 772
 773     // Get groupmode for activity, taking into account course settings
 774     $groupmode=groups_get_activity_groupmode($cm);
 775
 776     // If visible groups mode, or user has the accessallgroups capability,
 777     // then they can access all groups for the activity...
 778     $context = context_module::instance($cm->id);
 779     if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $context)) {
 780         return groups_get_all_groups($cm->course, 0, $cm->groupingid);
 781     } else {
 782         // ...otherwise they can only access groups they belong to
 783         return groups_get_all_groups($cm->course, $userid, $cm->groupingid);
 784     }
 785 }
 786
 787 /**
 788  * Determine if a course module is currently visible to a user
 789  *
 790  * $USER If $userid is null, use the global object.
 791  *
 792  * @category group
 793  * @param stdClass $cm The course module
 794  * @param int $userid The user to check against the group.
 795  * @return bool True if the user can view the course module, false otherwise.
 796  */
 797 function groups_course_module_visible($cm, $userid=null) {
 798     global $CFG, $USER;
 799
 800     if (empty($userid)) {
 801         $userid = $USER->id;
 802     }
 803     if (empty($CFG->enablegroupmembersonly)) {
 804         return true;
 805     }
 806     if (empty($cm->groupmembersonly)) {
 807         return true;
 808     }
 809     if (has_capability('moodle/site:accessallgroups', context_module::instance($cm->id), $userid) or groups_has_membership($cm, $userid)) {
 810         return true;
 811     }
 812     return false;
 813 }
 814
 815 /**
 816  * Internal method, sets up $SESSION->activegroup and verifies previous value
 817  *
 818  * @param int $courseid
 819  * @param int|string $groupmode SEPARATEGROUPS, VISIBLEGROUPS or 'aag' (access all groups)
 820  * @param int $groupingid 0 means all groups
 821  * @param array $allowedgroups list of groups user can see
 822  */
 823 function _group_verify_activegroup($courseid, $groupmode, $groupingid, array $allowedgroups) {
 824     global $SESSION, $USER;
 825
 826     // init activegroup array if necessary
 827     if (!isset($SESSION->activegroup)) {
 828         $SESSION->activegroup = array();
 829     }
 830     if (!array_key_exists($courseid, $SESSION->activegroup)) {
 831         $SESSION->activegroup[$courseid] = array(SEPARATEGROUPS=>array(), VISIBLEGROUPS=>array(), 'aag'=>array());
 832     }
 833
 834     // make sure that the current group info is ok
 835     if (array_key_exists($groupingid, $SESSION->activegroup[$courseid][$groupmode]) and !array_key_exists($SESSION->activegroup[$courseid][$groupmode][$groupingid], $allowedgroups)) {
 836         // active group does not exist anymore or is 0
 837         if ($SESSION->activegroup[$courseid][$groupmode][$groupingid] > 0 or $groupmode == SEPARATEGROUPS) {
 838             // do not do this if all groups selected and groupmode is not separate
 839             unset($SESSION->activegroup[$courseid][$groupmode][$groupingid]);
 840         }
 841     }
 842
 843     // set up defaults if necessary
 844     if (!array_key_exists($groupingid, $SESSION->activegroup[$courseid][$groupmode])) {
 845         if ($groupmode == 'aag') {
 846             $SESSION->activegroup[$courseid][$groupmode][$groupingid] = 0; // all groups by default if user has accessallgroups
 847
 848         } else if ($allowedgroups) {
 849             if ($groupmode != SEPARATEGROUPS and $mygroups = groups_get_all_groups($courseid, $USER->id, $groupingid)) {
 850                 $firstgroup = reset($mygroups);
 851             } else {
 852                 $firstgroup = reset($allowedgroups);
 853             }
 854             $SESSION->activegroup[$courseid][$groupmode][$groupingid] = $firstgroup->id;
 855
 856         } else {
 857             // this happen when user not assigned into group in SEPARATEGROUPS mode or groups do not exist yet
 858             // mod authors must add extra checks for this when SEPARATEGROUPS mode used (such as when posting to forum)
 859             $SESSION->activegroup[$courseid][$groupmode][$groupingid] = 0;
 860         }
 861     }
 862 }
 863
 864 /**
 865  * Caches group data for a particular course to speed up subsequent requests.
 866  *
 867  * @param int $courseid The course id to cache data for.
 868  * @param cache $cache The cache if it has already been initialised. If not a new one will be created.
 869  * @return stdClass A data object containing groups, groupings, and mappings.
 870  */
 871 function groups_cache_groupdata($courseid, cache $cache = null) {
 872     global $DB;
 873
 874     if ($cache === null) {
 875         // Initialise a cache if we wern't given one.
 876         $cache = cache::make('core', 'groupdata');
 877     }
 878
 879     // Get the groups that belong to the course.
 880     $groups = $DB->get_records('groups', array('courseid' => $courseid), 'name ASC');
 881     // Get the groupings that belong to the course.
 882     $groupings = $DB->get_records('groupings', array('courseid' => $courseid), 'name ASC');
 883
 884     if (!is_array($groups)) {
 885         $groups = array();
 886     }
 887
 888     if (!is_array($groupings)) {
 889         $groupings = array();
 890     }
 891
 892     if (!empty($groupings)) {
 893         // Finally get the mappings between the two.
 894         $mappings = $DB->get_records_list('groupings_groups', 'groupingid', array_keys($groupings), '', 'id,groupingid,groupid');
 895     } else {
 896         $mappings = array();
 897     }
 898
 899     // Prepare the data array.
 900     $data = new stdClass;
 901     $data->groups = $groups;
 902     $data->groupings = $groupings;
 903     $data->mappings = $mappings;
 904     // Cache the data.
 905     $cache->set($courseid, $data);
 906     // Finally return it so it can be used if desired.
 907     return $data;
 908 }
 909
 910 /**
 911  * Gets group data for a course.
 912  *
 913  * This returns an object with the following properties:
 914  *   - groups : An array of all the groups in the course.
 915  *   - groupings : An array of all the groupings within the course.
 916  *   - mappings : An array of group to grouping mappings.
 917  *
 918  * @param int $courseid The course id to get data for.
 919  * @param cache $cache The cache if it has already been initialised. If not a new one will be created.
 920  * @return stdClass
 921  */
 922 function groups_get_course_data($courseid, cache $cache = null) {
 923     if ($cache === null) {
 924         // Initialise a cache if we wern't given one.
 925         $cache = cache::make('core', 'groupdata');
 926     }
 927     // Try to retrieve it from the cache.
 928     $data = $cache->get($courseid);
 929     if ($data === false) {
 930         $data = groups_cache_groupdata($courseid, $cache);
 931     }
 932     return $data;
 933 }