cohort/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  * Cohort related management functions, this file needs to be included manually.
  19  *
  20  * @package    core_cohort
  21  * @copyright  2010 Petr Skoda  {@link http://skodak.org}
  22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 defined('MOODLE_INTERNAL') || die();
  26
  27 define('COHORT_ALL', 0);
  28 define('COHORT_COUNT_MEMBERS', 1);
  29 define('COHORT_COUNT_ENROLLED_MEMBERS', 3);
  30 define('COHORT_WITH_MEMBERS_ONLY', 5);
  31 define('COHORT_WITH_ENROLLED_MEMBERS_ONLY', 17);
  32 define('COHORT_WITH_NOTENROLLED_MEMBERS_ONLY', 23);
  33
  34 /**
  35  * Add new cohort.
  36  *
  37  * @param  stdClass $cohort
  38  * @return int new cohort id
  39  */
  40 function cohort_add_cohort($cohort) {
  41     global $DB, $CFG;
  42
  43     if (!isset($cohort->name)) {
  44         throw new coding_exception('Missing cohort name in cohort_add_cohort().');
  45     }
  46     if (!isset($cohort->idnumber)) {
  47         $cohort->idnumber = NULL;
  48     }
  49     if (!isset($cohort->description)) {
  50         $cohort->description = '';
  51     }
  52     if (!isset($cohort->descriptionformat)) {
  53         $cohort->descriptionformat = FORMAT_HTML;
  54     }
  55     if (!isset($cohort->visible)) {
  56         $cohort->visible = 1;
  57     }
  58     if (empty($cohort->component)) {
  59         $cohort->component = '';
  60     }
  61     if (empty($CFG->allowcohortthemes) && isset($cohort->theme)) {
  62         unset($cohort->theme);
  63     }
  64     if (empty($cohort->theme) || empty($CFG->allowcohortthemes)) {
  65         $cohort->theme = '';
  66     }
  67     if (!isset($cohort->timecreated)) {
  68         $cohort->timecreated = time();
  69     }
  70     if (!isset($cohort->timemodified)) {
  71         $cohort->timemodified = $cohort->timecreated;
  72     }
  73
  74     $cohort->id = $DB->insert_record('cohort', $cohort);
  75
  76     $event = \core\event\cohort_created::create(array(
  77         'context' => context::instance_by_id($cohort->contextid),
  78         'objectid' => $cohort->id,
  79     ));
  80     $event->add_record_snapshot('cohort', $cohort);
  81     $event->trigger();
  82
  83     return $cohort->id;
  84 }
  85
  86 /**
  87  * Update existing cohort.
  88  * @param  stdClass $cohort
  89  * @return void
  90  */
  91 function cohort_update_cohort($cohort) {
  92     global $DB, $CFG;
  93     if (property_exists($cohort, 'component') and empty($cohort->component)) {
  94         // prevent NULLs
  95         $cohort->component = '';
  96     }
  97     // Only unset the cohort theme if allowcohortthemes is enabled to prevent the value from being overwritten.
  98     if (empty($CFG->allowcohortthemes) && isset($cohort->theme)) {
  99         unset($cohort->theme);
 100     }
 101     $cohort->timemodified = time();
 102     $DB->update_record('cohort', $cohort);
 103
 104     $event = \core\event\cohort_updated::create(array(
 105         'context' => context::instance_by_id($cohort->contextid),
 106         'objectid' => $cohort->id,
 107     ));
 108     $event->trigger();
 109 }
 110
 111 /**
 112  * Delete cohort.
 113  * @param  stdClass $cohort
 114  * @return void
 115  */
 116 function cohort_delete_cohort($cohort) {
 117     global $DB;
 118
 119     if ($cohort->component) {
 120         // TODO: add component delete callback
 121     }
 122
 123     $DB->delete_records('cohort_members', array('cohortid'=>$cohort->id));
 124     $DB->delete_records('cohort', array('id'=>$cohort->id));
 125
 126     // Notify the competency subsystem.
 127     \core_competency\api::hook_cohort_deleted($cohort);
 128
 129     $event = \core\event\cohort_deleted::create(array(
 130         'context' => context::instance_by_id($cohort->contextid),
 131         'objectid' => $cohort->id,
 132     ));
 133     $event->add_record_snapshot('cohort', $cohort);
 134     $event->trigger();
 135 }
 136
 137 /**
 138  * Somehow deal with cohorts when deleting course category,
 139  * we can not just delete them because they might be used in enrol
 140  * plugins or referenced in external systems.
 141  * @param  stdClass|core_course_category $category
 142  * @return void
 143  */
 144 function cohort_delete_category($category) {
 145     global $DB;
 146     // TODO: make sure that cohorts are really, really not used anywhere and delete, for now just move to parent or system context
 147
 148     $oldcontext = context_coursecat::instance($category->id);
 149
 150     if ($category->parent and $parent = $DB->get_record('course_categories', array('id'=>$category->parent))) {
 151         $parentcontext = context_coursecat::instance($parent->id);
 152         $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
 153         $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$parentcontext->id);
 154     } else {
 155         $syscontext = context_system::instance();
 156         $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
 157         $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$syscontext->id);
 158     }
 159
 160     $DB->execute($sql, $params);
 161 }
 162
 163 /**
 164  * Add cohort member
 165  * @param  int $cohortid
 166  * @param  int $userid
 167  * @return void
 168  */
 169 function cohort_add_member($cohortid, $userid) {
 170     global $DB;
 171     if ($DB->record_exists('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid))) {
 172         // No duplicates!
 173         return;
 174     }
 175     $record = new stdClass();
 176     $record->cohortid  = $cohortid;
 177     $record->userid    = $userid;
 178     $record->timeadded = time();
 179     $DB->insert_record('cohort_members', $record);
 180
 181     $cohort = $DB->get_record('cohort', array('id' => $cohortid), '*', MUST_EXIST);
 182
 183     $event = \core\event\cohort_member_added::create(array(
 184         'context' => context::instance_by_id($cohort->contextid),
 185         'objectid' => $cohortid,
 186         'relateduserid' => $userid,
 187     ));
 188     $event->add_record_snapshot('cohort', $cohort);
 189     $event->trigger();
 190 }
 191
 192 /**
 193  * Remove cohort member
 194  * @param  int $cohortid
 195  * @param  int $userid
 196  * @return void
 197  */
 198 function cohort_remove_member($cohortid, $userid) {
 199     global $DB;
 200     $DB->delete_records('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid));
 201
 202     $cohort = $DB->get_record('cohort', array('id' => $cohortid), '*', MUST_EXIST);
 203
 204     $event = \core\event\cohort_member_removed::create(array(
 205         'context' => context::instance_by_id($cohort->contextid),
 206         'objectid' => $cohortid,
 207         'relateduserid' => $userid,
 208     ));
 209     $event->add_record_snapshot('cohort', $cohort);
 210     $event->trigger();
 211 }
 212
 213 /**
 214  * Is this user a cohort member?
 215  * @param int $cohortid
 216  * @param int $userid
 217  * @return bool
 218  */
 219 function cohort_is_member($cohortid, $userid) {
 220     global $DB;
 221
 222     return $DB->record_exists('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid));
 223 }
 224
 225 /**
 226  * Returns the list of cohorts visible to the current user in the given course.
 227  *
 228  * The following fields are returned in each record: id, name, contextid, idnumber, visible
 229  * Fields memberscnt and enrolledcnt will be also returned if requested
 230  *
 231  * @param context $currentcontext
 232  * @param int $withmembers one of the COHORT_XXX constants that allows to return non empty cohorts only
 233  *      or cohorts with enroled/not enroled users, or just return members count
 234  * @param int $offset
 235  * @param int $limit
 236  * @param string $search
 237  * @return array
 238  */
 239 function cohort_get_available_cohorts($currentcontext, $withmembers = 0, $offset = 0, $limit = 25, $search = '') {
 240     global $DB;
 241
 242     $params = array();
 243
 244     // Build context subquery. Find the list of parent context where user is able to see any or visible-only cohorts.
 245     // Since this method is normally called for the current course all parent contexts are already preloaded.
 246     $contextsany = array_filter($currentcontext->get_parent_context_ids(),
 247         function($a) {
 248             return has_capability("moodle/cohort:view", context::instance_by_id($a));
 249         });
 250     $contextsvisible = array_diff($currentcontext->get_parent_context_ids(), $contextsany);
 251     if (empty($contextsany) && empty($contextsvisible)) {
 252         // User does not have any permissions to view cohorts.
 253         return array();
 254     }
 255     $subqueries = array();
 256     if (!empty($contextsany)) {
 257         list($parentsql, $params1) = $DB->get_in_or_equal($contextsany, SQL_PARAMS_NAMED, 'ctxa');
 258         $subqueries[] = 'c.contextid ' . $parentsql;
 259         $params = array_merge($params, $params1);
 260     }
 261     if (!empty($contextsvisible)) {
 262         list($parentsql, $params1) = $DB->get_in_or_equal($contextsvisible, SQL_PARAMS_NAMED, 'ctxv');
 263         $subqueries[] = '(c.visible = 1 AND c.contextid ' . $parentsql. ')';
 264         $params = array_merge($params, $params1);
 265     }
 266     $wheresql = '(' . implode(' OR ', $subqueries) . ')';
 267
 268     // Build the rest of the query.
 269     $fromsql = "";
 270     $fieldssql = 'c.id, c.name, c.contextid, c.idnumber, c.visible';
 271     $groupbysql = '';
 272     $havingsql = '';
 273     if ($withmembers) {
 274         $fieldssql .= ', s.memberscnt';
 275         $subfields = "c.id, COUNT(DISTINCT cm.userid) AS memberscnt";
 276         $groupbysql = " GROUP BY c.id";
 277         $fromsql = " LEFT JOIN {cohort_members} cm ON cm.cohortid = c.id ";
 278         if (in_array($withmembers,
 279                 array(COHORT_COUNT_ENROLLED_MEMBERS, COHORT_WITH_ENROLLED_MEMBERS_ONLY, COHORT_WITH_NOTENROLLED_MEMBERS_ONLY))) {
 280             list($esql, $params2) = get_enrolled_sql($currentcontext);
 281             $fromsql .= " LEFT JOIN ($esql) u ON u.id = cm.userid ";
 282             $params = array_merge($params2, $params);
 283             $fieldssql .= ', s.enrolledcnt';
 284             $subfields .= ', COUNT(DISTINCT u.id) AS enrolledcnt';
 285         }
 286         if ($withmembers == COHORT_WITH_MEMBERS_ONLY) {
 287             $havingsql = " HAVING COUNT(DISTINCT cm.userid) > 0";
 288         } else if ($withmembers == COHORT_WITH_ENROLLED_MEMBERS_ONLY) {
 289             $havingsql = " HAVING COUNT(DISTINCT u.id) > 0";
 290         } else if ($withmembers == COHORT_WITH_NOTENROLLED_MEMBERS_ONLY) {
 291             $havingsql = " HAVING COUNT(DISTINCT cm.userid) > COUNT(DISTINCT u.id)";
 292         }
 293     }
 294     if ($search) {
 295         list($searchsql, $searchparams) = cohort_get_search_query($search);
 296         $wheresql .= ' AND ' . $searchsql;
 297         $params = array_merge($params, $searchparams);
 298     }
 299
 300     if ($withmembers) {
 301         $sql = "SELECT " . str_replace('c.', 'cohort.', $fieldssql) . "
 302                   FROM {cohort} cohort
 303                   JOIN (SELECT $subfields
 304                           FROM {cohort} c $fromsql
 305                          WHERE $wheresql $groupbysql $havingsql
 306                         ) s ON cohort.id = s.id
 307               ORDER BY cohort.name, cohort.idnumber";
 308     } else {
 309         $sql = "SELECT $fieldssql
 310                   FROM {cohort} c $fromsql
 311                  WHERE $wheresql
 312               ORDER BY c.name, c.idnumber";
 313     }
 314
 315     return $DB->get_records_sql($sql, $params, $offset, $limit);
 316 }
 317
 318 /**
 319  * Check if cohort exists and user is allowed to access it from the given context.
 320  *
 321  * @param stdClass|int $cohortorid cohort object or id
 322  * @param context $currentcontext current context (course) where visibility is checked
 323  * @return boolean
 324  */
 325 function cohort_can_view_cohort($cohortorid, $currentcontext) {
 326     global $DB;
 327     if (is_numeric($cohortorid)) {
 328         $cohort = $DB->get_record('cohort', array('id' => $cohortorid), 'id, contextid, visible');
 329     } else {
 330         $cohort = $cohortorid;
 331     }
 332
 333     if ($cohort && in_array($cohort->contextid, $currentcontext->get_parent_context_ids())) {
 334         if ($cohort->visible) {
 335             return true;
 336         }
 337         $cohortcontext = context::instance_by_id($cohort->contextid);
 338         if (has_capability('moodle/cohort:view', $cohortcontext)) {
 339             return true;
 340         }
 341     }
 342     return false;
 343 }
 344
 345 /**
 346  * Get a cohort by id. Also does a visibility check and returns false if the user cannot see this cohort.
 347  *
 348  * @param stdClass|int $cohortorid cohort object or id
 349  * @param context $currentcontext current context (course) where visibility is checked
 350  * @return stdClass|boolean
 351  */
 352 function cohort_get_cohort($cohortorid, $currentcontext) {
 353     global $DB;
 354     if (is_numeric($cohortorid)) {
 355         $cohort = $DB->get_record('cohort', array('id' => $cohortorid), 'id, contextid, visible');
 356     } else {
 357         $cohort = $cohortorid;
 358     }
 359
 360     if ($cohort && in_array($cohort->contextid, $currentcontext->get_parent_context_ids())) {
 361         if ($cohort->visible) {
 362             return $cohort;
 363         }
 364         $cohortcontext = context::instance_by_id($cohort->contextid);
 365         if (has_capability('moodle/cohort:view', $cohortcontext)) {
 366             return $cohort;
 367         }
 368     }
 369     return false;
 370 }
 371
 372 /**
 373  * Produces a part of SQL query to filter cohorts by the search string
 374  *
 375  * Called from {@link cohort_get_cohorts()}, {@link cohort_get_all_cohorts()} and {@link cohort_get_available_cohorts()}
 376  *
 377  * @access private
 378  *
 379  * @param string $search search string
 380  * @param string $tablealias alias of cohort table in the SQL query (highly recommended if other tables are used in query)
 381  * @return array of two elements - SQL condition and array of named parameters
 382  */
 383 function cohort_get_search_query($search, $tablealias = '') {
 384     global $DB;
 385     $params = array();
 386     if (empty($search)) {
 387         // This function should not be called if there is no search string, just in case return dummy query.
 388         return array('1=1', $params);
 389     }
 390     if ($tablealias && substr($tablealias, -1) !== '.') {
 391         $tablealias .= '.';
 392     }
 393     $searchparam = '%' . $DB->sql_like_escape($search) . '%';
 394     $conditions = array();
 395     $fields = array('name', 'idnumber', 'description');
 396     $cnt = 0;
 397     foreach ($fields as $field) {
 398         $conditions[] = $DB->sql_like($tablealias . $field, ':csearch' . $cnt, false);
 399         $params['csearch' . $cnt] = $searchparam;
 400         $cnt++;
 401     }
 402     $sql = '(' . implode(' OR ', $conditions) . ')';
 403     return array($sql, $params);
 404 }
 405
 406 /**
 407  * Get all the cohorts defined in given context.
 408  *
 409  * The function does not check user capability to view/manage cohorts in the given context
 410  * assuming that it has been already verified.
 411  *
 412  * @param int $contextid
 413  * @param int $page number of the current page
 414  * @param int $perpage items per page
 415  * @param string $search search string
 416  * @return array    Array(totalcohorts => int, cohorts => array, allcohorts => int)
 417  */
 418 function cohort_get_cohorts($contextid, $page = 0, $perpage = 25, $search = '') {
 419     global $DB;
 420
 421     $fields = "SELECT *";
 422     $countfields = "SELECT COUNT(1)";
 423     $sql = " FROM {cohort}
 424              WHERE contextid = :contextid";
 425     $params = array('contextid' => $contextid);
 426     $order = " ORDER BY name ASC, idnumber ASC";
 427
 428     if (!empty($search)) {
 429         list($searchcondition, $searchparams) = cohort_get_search_query($search);
 430         $sql .= ' AND ' . $searchcondition;
 431         $params = array_merge($params, $searchparams);
 432     }
 433
 434     $totalcohorts = $allcohorts = $DB->count_records('cohort', array('contextid' => $contextid));
 435     if (!empty($search)) {
 436         $totalcohorts = $DB->count_records_sql($countfields . $sql, $params);
 437     }
 438     $cohorts = $DB->get_records_sql($fields . $sql . $order, $params, $page*$perpage, $perpage);
 439
 440     return array('totalcohorts' => $totalcohorts, 'cohorts' => $cohorts, 'allcohorts' => $allcohorts);
 441 }
 442
 443 /**
 444  * Get all the cohorts defined anywhere in system.
 445  *
 446  * The function assumes that user capability to view/manage cohorts on system level
 447  * has already been verified. This function only checks if such capabilities have been
 448  * revoked in child (categories) contexts.
 449  *
 450  * @param int $page number of the current page
 451  * @param int $perpage items per page
 452  * @param string $search search string
 453  * @return array    Array(totalcohorts => int, cohorts => array, allcohorts => int)
 454  */
 455 function cohort_get_all_cohorts($page = 0, $perpage = 25, $search = '') {
 456     global $DB;
 457
 458     $fields = "SELECT c.*, ".context_helper::get_preload_record_columns_sql('ctx');
 459     $countfields = "SELECT COUNT(*)";
 460     $sql = " FROM {cohort} c
 461              JOIN {context} ctx ON ctx.id = c.contextid ";
 462     $params = array();
 463     $wheresql = '';
 464
 465     if ($excludedcontexts = cohort_get_invisible_contexts()) {
 466         list($excludedsql, $excludedparams) = $DB->get_in_or_equal($excludedcontexts, SQL_PARAMS_NAMED, 'excl', false);
 467         $wheresql = ' WHERE c.contextid '.$excludedsql;
 468         $params = array_merge($params, $excludedparams);
 469     }
 470
 471     $totalcohorts = $allcohorts = $DB->count_records_sql($countfields . $sql . $wheresql, $params);
 472
 473     if (!empty($search)) {
 474         list($searchcondition, $searchparams) = cohort_get_search_query($search, 'c');
 475         $wheresql .= ($wheresql ? ' AND ' : ' WHERE ') . $searchcondition;
 476         $params = array_merge($params, $searchparams);
 477         $totalcohorts = $DB->count_records_sql($countfields . $sql . $wheresql, $params);
 478     }
 479
 480     $order = " ORDER BY c.name ASC, c.idnumber ASC";
 481     $cohorts = $DB->get_records_sql($fields . $sql . $wheresql . $order, $params, $page*$perpage, $perpage);
 482
 483     // Preload used contexts, they will be used to check view/manage/assign capabilities and display categories names.
 484     foreach (array_keys($cohorts) as $key) {
 485         context_helper::preload_from_record($cohorts[$key]);
 486     }
 487
 488     return array('totalcohorts' => $totalcohorts, 'cohorts' => $cohorts, 'allcohorts' => $allcohorts);
 489 }
 490
 491 /**
 492  * Get all the cohorts where the given user is member of.
 493  *
 494  * @param int $userid
 495  * @return array Array
 496  */
 497 function cohort_get_user_cohorts($userid) {
 498     global $DB;
 499
 500     $sql = 'SELECT c.*
 501               FROM {cohort} c
 502               JOIN {cohort_members} cm ON c.id = cm.cohortid
 503              WHERE cm.userid = ? AND c.visible = 1';
 504     return $DB->get_records_sql($sql, array($userid));
 505 }
 506
 507 /**
 508  * Get the user cohort theme.
 509  *
 510  * If the user is member of one cohort, will return this cohort theme (if defined).
 511  * If the user is member of 2 or more cohorts, will return the theme if all them have the same
 512  * theme (null themes are ignored).
 513  *
 514  * @param int $userid
 515  * @return string|null
 516  */
 517 function cohort_get_user_cohort_theme($userid) {
 518     $cohorts = cohort_get_user_cohorts($userid);
 519     $theme = null;
 520     foreach ($cohorts as $cohort) {
 521         if (!empty($cohort->theme)) {
 522             if (null === $theme) {
 523                 $theme = $cohort->theme;
 524             } else if ($theme != $cohort->theme) {
 525                 return null;
 526             }
 527         }
 528     }
 529     return $theme;
 530 }
 531
 532 /**
 533  * Returns list of contexts where cohorts are present but current user does not have capability to view/manage them.
 534  *
 535  * This function is called from {@link cohort_get_all_cohorts()} to ensure correct pagination in rare cases when user
 536  * is revoked capability in child contexts. It assumes that user's capability to view/manage cohorts on system
 537  * level has already been verified.
 538  *
 539  * @access private
 540  *
 541  * @return array array of context ids
 542  */
 543 function cohort_get_invisible_contexts() {
 544     global $DB;
 545     if (is_siteadmin()) {
 546         // Shortcut, admin can do anything and can not be prohibited from any context.
 547         return array();
 548     }
 549     $records = $DB->get_recordset_sql("SELECT DISTINCT ctx.id, ".context_helper::get_preload_record_columns_sql('ctx')." ".
 550         "FROM {context} ctx JOIN {cohort} c ON ctx.id = c.contextid ");
 551     $excludedcontexts = array();
 552     foreach ($records as $ctx) {
 553         context_helper::preload_from_record($ctx);
 554         if (context::instance_by_id($ctx->id) == context_system::instance()) {
 555             continue; // System context cohorts should be available and permissions already checked.
 556         }
 557         if (!has_any_capability(array('moodle/cohort:manage', 'moodle/cohort:view'), context::instance_by_id($ctx->id))) {
 558             $excludedcontexts[] = $ctx->id;
 559         }
 560     }
 561     $records->close();
 562     return $excludedcontexts;
 563 }
 564
 565 /**
 566  * Returns navigation controls (tabtree) to be displayed on cohort management pages
 567  *
 568  * @param context $context system or category context where cohorts controls are about to be displayed
 569  * @param moodle_url $currenturl
 570  * @return null|renderable
 571  */
 572 function cohort_edit_controls(context $context, moodle_url $currenturl) {
 573     $tabs = array();
 574     $currenttab = 'view';
 575     $viewurl = new moodle_url('/cohort/index.php', array('contextid' => $context->id));
 576     if (($searchquery = $currenturl->get_param('search'))) {
 577         $viewurl->param('search', $searchquery);
 578     }
 579     if ($context->contextlevel == CONTEXT_SYSTEM) {
 580         $tabs[] = new tabobject('view', new moodle_url($viewurl, array('showall' => 0)), get_string('systemcohorts', 'cohort'));
 581         $tabs[] = new tabobject('viewall', new moodle_url($viewurl, array('showall' => 1)), get_string('allcohorts', 'cohort'));
 582         if ($currenturl->get_param('showall')) {
 583             $currenttab = 'viewall';
 584         }
 585     } else {
 586         $tabs[] = new tabobject('view', $viewurl, get_string('cohorts', 'cohort'));
 587     }
 588     if (has_capability('moodle/cohort:manage', $context)) {
 589         $addurl = new moodle_url('/cohort/edit.php', array('contextid' => $context->id));
 590         $tabs[] = new tabobject('addcohort', $addurl, get_string('addcohort', 'cohort'));
 591         if ($currenturl->get_path() === $addurl->get_path() && !$currenturl->param('id')) {
 592             $currenttab = 'addcohort';
 593         }
 594
 595         $uploadurl = new moodle_url('/cohort/upload.php', array('contextid' => $context->id));
 596         $tabs[] = new tabobject('uploadcohorts', $uploadurl, get_string('uploadcohorts', 'cohort'));
 597         if ($currenturl->get_path() === $uploadurl->get_path()) {
 598             $currenttab = 'uploadcohorts';
 599         }
 600     }
 601     if (count($tabs) > 1) {
 602         return new tabtree($tabs, $currenttab);
 603     }
 604     return null;
 605 }
 606
 607 /**
 608  * Implements callback inplace_editable() allowing to edit values in-place
 609  *
 610  * @param string $itemtype
 611  * @param int $itemid
 612  * @param mixed $newvalue
 613  * @return \core\output\inplace_editable
 614  */
 615 function core_cohort_inplace_editable($itemtype, $itemid, $newvalue) {
 616     if ($itemtype === 'cohortname') {
 617         return \core_cohort\output\cohortname::update($itemid, $newvalue);
 618     } else if ($itemtype === 'cohortidnumber') {
 619         return \core_cohort\output\cohortidnumber::update($itemid, $newvalue);
 620     }
 621 }
 622
 623 /**
 624  * Returns a list of valid themes which can be displayed in a selector.
 625  *
 626  * @return array as (string)themename => (string)get_string_theme
 627  */
 628 function cohort_get_list_of_themes() {
 629     $themes = array();
 630     $allthemes = get_list_of_themes();
 631     foreach ($allthemes as $key => $theme) {
 632         if (empty($theme->hidefromselector)) {
 633             $themes[$key] = get_string('pluginname', 'theme_'.$theme->name);
 634         }
 635     }
 636     return $themes;
 637 }