cohort/externallib.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  * External cohort API
  19  *
  20  * @package    core_cohort
  21  * @category   external
  22  * @copyright  MediaTouch 2000 srl
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26 defined('MOODLE_INTERNAL') || die();
  27
  28 require_once("$CFG->libdir/externallib.php");
  29
  30 class core_cohort_external extends external_api {
  31
  32     /**
  33      * Returns description of method parameters
  34      *
  35      * @return external_function_parameters
  36      * @since Moodle 2.5
  37      */
  38     public static function create_cohorts_parameters() {
  39         return new external_function_parameters(
  40             array(
  41                 'cohorts' => new external_multiple_structure(
  42                     new external_single_structure(
  43                         array(
  44                             'categorytype' => new external_single_structure(
  45                                 array(
  46                                     'type' => new external_value(PARAM_TEXT, 'the name of the field: id (numeric value
  47                                         of course category id) or idnumber (alphanumeric value of idnumber course category)
  48                                         or system (value ignored)'),
  49                                     'value' => new external_value(PARAM_RAW, 'the value of the categorytype')
  50                                 )
  51                             ),
  52                             'name' => new external_value(PARAM_RAW, 'cohort name'),
  53                             'idnumber' => new external_value(PARAM_RAW, 'cohort idnumber'),
  54                             'description' => new external_value(PARAM_RAW, 'cohort description', VALUE_OPTIONAL),
  55                             'descriptionformat' => new external_format_value('description', VALUE_DEFAULT),
  56                             'visible' => new external_value(PARAM_BOOL, 'cohort visible', VALUE_OPTIONAL, true),
  57                         )
  58                     )
  59                 )
  60             )
  61         );
  62     }
  63
  64     /**
  65      * Create one or more cohorts
  66      *
  67      * @param array $cohorts An array of cohorts to create.
  68      * @return array An array of arrays
  69      * @since Moodle 2.5
  70      */
  71     public static function create_cohorts($cohorts) {
  72         global $CFG, $DB;
  73         require_once("$CFG->dirroot/cohort/lib.php");
  74
  75         $params = self::validate_parameters(self::create_cohorts_parameters(), array('cohorts' => $cohorts));
  76
  77         $transaction = $DB->start_delegated_transaction();
  78
  79         $syscontext = context_system::instance();
  80         $cohortids = array();
  81
  82         foreach ($params['cohorts'] as $cohort) {
  83             $cohort = (object)$cohort;
  84
  85             // Category type (context id).
  86             $categorytype = $cohort->categorytype;
  87             if (!in_array($categorytype['type'], array('idnumber', 'id', 'system'))) {
  88                 throw new invalid_parameter_exception('category type must be id, idnumber or system:' . $categorytype['type']);
  89             }
  90             if ($categorytype['type'] === 'system') {
  91                 $cohort->contextid = $syscontext->id;
  92             } else if ($catid = $DB->get_field('course_categories', 'id', array($categorytype['type'] => $categorytype['value']))) {
  93                 $catcontext = context_coursecat::instance($catid);
  94                 $cohort->contextid = $catcontext->id;
  95             } else {
  96                 throw new invalid_parameter_exception('category not exists: category '
  97                     .$categorytype['type'].' = '.$categorytype['value']);
  98             }
  99             // Make sure that the idnumber doesn't already exist.
 100             if ($DB->record_exists('cohort', array('idnumber' => $cohort->idnumber))) {
 101                 throw new invalid_parameter_exception('record already exists: idnumber='.$cohort->idnumber);
 102             }
 103             $context = context::instance_by_id($cohort->contextid, MUST_EXIST);
 104             if ($context->contextlevel != CONTEXT_COURSECAT and $context->contextlevel != CONTEXT_SYSTEM) {
 105                 throw new invalid_parameter_exception('Invalid context');
 106             }
 107             self::validate_context($context);
 108             require_capability('moodle/cohort:manage', $context);
 109
 110             // Validate format.
 111             $cohort->descriptionformat = external_validate_format($cohort->descriptionformat);
 112             $cohort->id = cohort_add_cohort($cohort);
 113
 114             list($cohort->description, $cohort->descriptionformat) =
 115                 external_format_text($cohort->description, $cohort->descriptionformat,
 116                         $context->id, 'cohort', 'description', $cohort->id);
 117             $cohortids[] = (array)$cohort;
 118         }
 119         $transaction->allow_commit();
 120
 121         return $cohortids;
 122     }
 123
 124     /**
 125      * Returns description of method result value
 126      *
 127      * @return external_description
 128      * @since Moodle 2.5
 129      */
 130     public static function create_cohorts_returns() {
 131         return new external_multiple_structure(
 132             new external_single_structure(
 133                 array(
 134                     'id' => new external_value(PARAM_INT, 'cohort id'),
 135                     'name' => new external_value(PARAM_RAW, 'cohort name'),
 136                     'idnumber' => new external_value(PARAM_RAW, 'cohort idnumber'),
 137                     'description' => new external_value(PARAM_RAW, 'cohort description'),
 138                     'descriptionformat' => new external_format_value('description'),
 139                     'visible' => new external_value(PARAM_BOOL, 'cohort visible'),
 140                 )
 141             )
 142         );
 143     }
 144
 145     /**
 146      * Returns description of method parameters
 147      *
 148      * @return external_function_parameters
 149      * @since Moodle 2.5
 150      */
 151     public static function delete_cohorts_parameters() {
 152         return new external_function_parameters(
 153             array(
 154                 'cohortids' => new external_multiple_structure(new external_value(PARAM_INT, 'cohort ID')),
 155             )
 156         );
 157     }
 158
 159     /**
 160      * Delete cohorts
 161      *
 162      * @param array $cohortids
 163      * @return null
 164      * @since Moodle 2.5
 165      */
 166     public static function delete_cohorts($cohortids) {
 167         global $CFG, $DB;
 168         require_once("$CFG->dirroot/cohort/lib.php");
 169
 170         $params = self::validate_parameters(self::delete_cohorts_parameters(), array('cohortids' => $cohortids));
 171
 172         $transaction = $DB->start_delegated_transaction();
 173
 174         foreach ($params['cohortids'] as $cohortid) {
 175             // Validate params.
 176             $cohortid = validate_param($cohortid, PARAM_INT);
 177             $cohort = $DB->get_record('cohort', array('id' => $cohortid), '*', MUST_EXIST);
 178
 179             // Now security checks.
 180             $context = context::instance_by_id($cohort->contextid, MUST_EXIST);
 181             if ($context->contextlevel != CONTEXT_COURSECAT and $context->contextlevel != CONTEXT_SYSTEM) {
 182                 throw new invalid_parameter_exception('Invalid context');
 183             }
 184             self::validate_context($context);
 185             require_capability('moodle/cohort:manage', $context);
 186             cohort_delete_cohort($cohort);
 187         }
 188         $transaction->allow_commit();
 189
 190         return null;
 191     }
 192
 193     /**
 194      * Returns description of method result value
 195      *
 196      * @return null
 197      * @since Moodle 2.5
 198      */
 199     public static function delete_cohorts_returns() {
 200         return null;
 201     }
 202
 203     /**
 204      * Returns description of method parameters
 205      *
 206      * @return external_function_parameters
 207      * @since Moodle 2.5
 208      */
 209     public static function get_cohorts_parameters() {
 210         return new external_function_parameters(
 211             array(
 212                 'cohortids' => new external_multiple_structure(new external_value(PARAM_INT, 'Cohort ID')
 213                     , 'List of cohort id. A cohort id is an integer.', VALUE_DEFAULT, array()),
 214             )
 215         );
 216     }
 217
 218     /**
 219      * Get cohorts definition specified by ids
 220      *
 221      * @param array $cohortids array of cohort ids
 222      * @return array of cohort objects (id, courseid, name)
 223      * @since Moodle 2.5
 224      */
 225     public static function get_cohorts($cohortids = array()) {
 226         global $DB;
 227
 228         $params = self::validate_parameters(self::get_cohorts_parameters(), array('cohortids' => $cohortids));
 229
 230         if (empty($cohortids)) {
 231             $cohorts = $DB->get_records('cohort');
 232         } else {
 233             $cohorts = $DB->get_records_list('cohort', 'id', $params['cohortids']);
 234         }
 235
 236         $cohortsinfo = array();
 237         foreach ($cohorts as $cohort) {
 238             // Now security checks.
 239             $context = context::instance_by_id($cohort->contextid, MUST_EXIST);
 240             if ($context->contextlevel != CONTEXT_COURSECAT and $context->contextlevel != CONTEXT_SYSTEM) {
 241                 throw new invalid_parameter_exception('Invalid context');
 242             }
 243             self::validate_context($context);
 244             if (!has_any_capability(array('moodle/cohort:manage', 'moodle/cohort:view'), $context)) {
 245                 throw new required_capability_exception($context, 'moodle/cohort:view', 'nopermissions', '');
 246             }
 247
 248             list($cohort->description, $cohort->descriptionformat) =
 249                 external_format_text($cohort->description, $cohort->descriptionformat,
 250                         $context->id, 'cohort', 'description', $cohort->id);
 251
 252             $cohortsinfo[] = (array) $cohort;
 253         }
 254         return $cohortsinfo;
 255     }
 256
 257
 258     /**
 259      * Returns description of method result value
 260      *
 261      * @return external_description
 262      * @since Moodle 2.5
 263      */
 264     public static function get_cohorts_returns() {
 265         return new external_multiple_structure(
 266             new external_single_structure(
 267                 array(
 268                     'id' => new external_value(PARAM_INT, 'ID of the cohort'),
 269                     'name' => new external_value(PARAM_RAW, 'cohort name'),
 270                     'idnumber' => new external_value(PARAM_RAW, 'cohort idnumber'),
 271                     'description' => new external_value(PARAM_RAW, 'cohort description'),
 272                     'descriptionformat' => new external_format_value('description'),
 273                     'visible' => new external_value(PARAM_BOOL, 'cohort visible'),
 274                 )
 275             )
 276         );
 277     }
 278
 279     /**
 280      * Returns description of method parameters
 281      *
 282      * @return external_function_parameters
 283      * @since Moodle 2.5
 284      */
 285     public static function update_cohorts_parameters() {
 286         return new external_function_parameters(
 287             array(
 288                 'cohorts' => new external_multiple_structure(
 289                     new external_single_structure(
 290                         array(
 291                             'id' => new external_value(PARAM_INT, 'ID of the cohort'),
 292                             'categorytype' => new external_single_structure(
 293                                 array(
 294                                     'type' => new external_value(PARAM_TEXT, 'the name of the field: id (numeric value
 295                                         of course category id) or idnumber (alphanumeric value of idnumber course category)
 296                                         or system (value ignored)'),
 297                                     'value' => new external_value(PARAM_RAW, 'the value of the categorytype')
 298                                 )
 299                             ),
 300                             'name' => new external_value(PARAM_RAW, 'cohort name'),
 301                             'idnumber' => new external_value(PARAM_RAW, 'cohort idnumber'),
 302                             'description' => new external_value(PARAM_RAW, 'cohort description', VALUE_OPTIONAL),
 303                             'descriptionformat' => new external_format_value('description', VALUE_DEFAULT),
 304                             'visible' => new external_value(PARAM_BOOL, 'cohort visible', VALUE_OPTIONAL),
 305                         )
 306                     )
 307                 )
 308             )
 309         );
 310     }
 311
 312     /**
 313      * Update cohorts
 314      *
 315      * @param array $cohorts
 316      * @return null
 317      * @since Moodle 2.5
 318      */
 319     public static function update_cohorts($cohorts) {
 320         global $CFG, $DB;
 321         require_once("$CFG->dirroot/cohort/lib.php");
 322
 323         $params = self::validate_parameters(self::update_cohorts_parameters(), array('cohorts' => $cohorts));
 324
 325         $transaction = $DB->start_delegated_transaction();
 326         $syscontext = context_system::instance();
 327
 328         foreach ($params['cohorts'] as $cohort) {
 329             $cohort = (object) $cohort;
 330
 331             if (trim($cohort->name) == '') {
 332                 throw new invalid_parameter_exception('Invalid cohort name');
 333             }
 334
 335             $oldcohort = $DB->get_record('cohort', array('id' => $cohort->id), '*', MUST_EXIST);
 336             $oldcontext = context::instance_by_id($oldcohort->contextid, MUST_EXIST);
 337             require_capability('moodle/cohort:manage', $oldcontext);
 338
 339             // Category type (context id).
 340             $categorytype = $cohort->categorytype;
 341             if (!in_array($categorytype['type'], array('idnumber', 'id', 'system'))) {
 342                 throw new invalid_parameter_exception('category type must be id, idnumber or system:' . $categorytype['type']);
 343             }
 344             if ($categorytype['type'] === 'system') {
 345                 $cohort->contextid = $syscontext->id;
 346             } else if ($catid = $DB->get_field('course_categories', 'id', array($categorytype['type'] => $categorytype['value']))) {
 347                 $cohort->contextid = $DB->get_field('context', 'id', array('instanceid' => $catid,
 348                     'contextlevel' => CONTEXT_COURSECAT));
 349             } else {
 350                 throw new invalid_parameter_exception('category not exists: category='.$categorytype['value']);
 351             }
 352
 353             if ($cohort->contextid != $oldcohort->contextid) {
 354                 $context = context::instance_by_id($cohort->contextid, MUST_EXIST);
 355                 if ($context->contextlevel != CONTEXT_COURSECAT and $context->contextlevel != CONTEXT_SYSTEM) {
 356                     throw new invalid_parameter_exception('Invalid context');
 357                 }
 358
 359                 self::validate_context($context);
 360                 require_capability('moodle/cohort:manage', $context);
 361             }
 362
 363             if (!empty($cohort->description)) {
 364                 $cohort->descriptionformat = external_validate_format($cohort->descriptionformat);
 365             }
 366
 367             cohort_update_cohort($cohort);
 368         }
 369
 370         $transaction->allow_commit();
 371
 372         return null;
 373     }
 374
 375     /**
 376      * Returns description of method result value
 377      *
 378      * @return null
 379      * @since Moodle 2.5
 380      */
 381     public static function update_cohorts_returns() {
 382         return null;
 383     }
 384
 385     /**
 386      * Returns description of method parameters
 387      *
 388      * @return external_function_parameters
 389      * @since Moodle 2.5
 390      */
 391     public static function add_cohort_members_parameters() {
 392         return new external_function_parameters (
 393             array(
 394                 'members' => new external_multiple_structure (
 395                     new external_single_structure (
 396                         array (
 397                             'cohorttype' => new external_single_structure (
 398                                 array(
 399                                     'type' => new external_value(PARAM_ALPHANUMEXT, 'The name of the field: id
 400                                         (numeric value of cohortid) or idnumber (alphanumeric value of idnumber) '),
 401                                     'value' => new external_value(PARAM_RAW, 'The value of the cohort')
 402                                 )
 403                             ),
 404                             'usertype' => new external_single_structure (
 405                                 array(
 406                                     'type' => new external_value(PARAM_ALPHANUMEXT, 'The name of the field: id
 407                                         (numeric value of id) or username (alphanumeric value of username) '),
 408                                     'value' => new external_value(PARAM_RAW, 'The value of the cohort')
 409                                 )
 410                             )
 411                         )
 412                     )
 413                 )
 414             )
 415         );
 416     }
 417
 418     /**
 419      * Add cohort members
 420      *
 421      * @param array $members of arrays with keys userid, cohortid
 422      * @since Moodle 2.5
 423      */
 424     public static function add_cohort_members($members) {
 425         global $CFG, $DB;
 426         require_once($CFG->dirroot."/cohort/lib.php");
 427
 428         $params = self::validate_parameters(self::add_cohort_members_parameters(), array('members' => $members));
 429
 430         $transaction = $DB->start_delegated_transaction();
 431         $warnings = array();
 432         foreach ($params['members'] as $member) {
 433             // Cohort parameters.
 434             $cohorttype = $member['cohorttype'];
 435             $cohortparam = array($cohorttype['type'] => $cohorttype['value']);
 436             // User parameters.
 437             $usertype = $member['usertype'];
 438             $userparam = array($usertype['type'] => $usertype['value']);
 439             try {
 440                 // Check parameters.
 441                 if ($cohorttype['type'] != 'id' && $cohorttype['type'] != 'idnumber') {
 442                     $warning = array();
 443                     $warning['warningcode'] = '1';
 444                     $warning['message'] = 'invalid parameter: cohortype='.$cohorttype['type'];
 445                     $warnings[] = $warning;
 446                     continue;
 447                 }
 448                 if ($usertype['type'] != 'id' && $usertype['type'] != 'username') {
 449                     $warning = array();
 450                     $warning['warningcode'] = '1';
 451                     $warning['message'] = 'invalid parameter: usertype='.$usertype['type'];
 452                     $warnings[] = $warning;
 453                     continue;
 454                 }
 455                 // Extract parameters.
 456                 if (!$cohortid = $DB->get_field('cohort', 'id', $cohortparam)) {
 457                     $warning = array();
 458                     $warning['warningcode'] = '2';
 459                     $warning['message'] = 'cohort '.$cohorttype['type'].'='.$cohorttype['value'].' not exists';
 460                     $warnings[] = $warning;
 461                     continue;
 462                 }
 463                 if (!$userid = $DB->get_field('user', 'id', array_merge($userparam, array('deleted' => 0,
 464                     'mnethostid' => $CFG->mnet_localhost_id)))) {
 465                     $warning = array();
 466                     $warning['warningcode'] = '2';
 467                     $warning['message'] = 'user '.$usertype['type'].'='.$usertype['value'].' not exists';
 468                     $warnings[] = $warning;
 469                     continue;
 470                 }
 471                 if ($DB->record_exists('cohort_members', array('cohortid' => $cohortid, 'userid' => $userid))) {
 472                     $warning = array();
 473                     $warning['warningcode'] = '3';
 474                     $warning['message'] = 'record already exists: cohort('.$cohorttype['type'].'='.$cohorttype['value'].' '.
 475                         $usertype['type'].'='.$usertype['value'].')';
 476                     $warnings[] = $warning;
 477                     continue;
 478                 }
 479                 $cohort = $DB->get_record('cohort', array('id'=>$cohortid), '*', MUST_EXIST);
 480                 $context = context::instance_by_id($cohort->contextid, MUST_EXIST);
 481                 if ($context->contextlevel != CONTEXT_COURSECAT and $context->contextlevel != CONTEXT_SYSTEM) {
 482                     $warning = array();
 483                     $warning['warningcode'] = '1';
 484                     $warning['message'] = 'Invalid context: '.$context->contextlevel;
 485                     $warnings[] = $warning;
 486                     continue;
 487                 }
 488                 self::validate_context($context);
 489             } catch (Exception $e) {
 490                 throw new moodle_exception('Error', 'cohort', '', $e->getMessage());
 491             }
 492             if (!has_any_capability(array('moodle/cohort:manage', 'moodle/cohort:assign'), $context)) {
 493                 throw new required_capability_exception($context, 'moodle/cohort:assign', 'nopermissions', '');
 494             }
 495             cohort_add_member($cohortid, $userid);
 496         }
 497         $transaction->allow_commit();
 498         // Return.
 499         $result = array();
 500         $result['warnings'] = $warnings;
 501         return $result;
 502     }
 503
 504     /**
 505      * Returns description of method result value
 506      *
 507      * @return null
 508      * @since Moodle 2.5
 509      */
 510     public static function add_cohort_members_returns() {
 511         return new external_single_structure(
 512             array(
 513                 'warnings' => new external_warnings()
 514             )
 515         );
 516     }
 517
 518     /**
 519      * Returns description of method parameters
 520      *
 521      * @return external_function_parameters
 522      * @since Moodle 2.5
 523      */
 524     public static function delete_cohort_members_parameters() {
 525         return new external_function_parameters(
 526             array(
 527                 'members' => new external_multiple_structure(
 528                     new external_single_structure(
 529                         array(
 530                             'cohortid' => new external_value(PARAM_INT, 'cohort record id'),
 531                             'userid' => new external_value(PARAM_INT, 'user id'),
 532                         )
 533                     )
 534                 )
 535             )
 536         );
 537     }
 538
 539     /**
 540      * Delete cohort members
 541      *
 542      * @param array $members of arrays with keys userid, cohortid
 543      * @since Moodle 2.5
 544      */
 545     public static function delete_cohort_members($members) {
 546         global $CFG, $DB;
 547         require_once("$CFG->dirroot/cohort/lib.php");
 548
 549         // Validate parameters.
 550         $params = self::validate_parameters(self::delete_cohort_members_parameters(), array('members' => $members));
 551
 552         $transaction = $DB->start_delegated_transaction();
 553
 554         foreach ($params['members'] as $member) {
 555             $cohortid = $member['cohortid'];
 556             $userid = $member['userid'];
 557
 558             $cohort = $DB->get_record('cohort', array('id' => $cohortid), '*', MUST_EXIST);
 559             $user = $DB->get_record('user', array('id' => $userid, 'deleted' => 0, 'mnethostid' => $CFG->mnet_localhost_id),
 560                 '*', MUST_EXIST);
 561
 562             // Now security checks.
 563             $context = context::instance_by_id($cohort->contextid, MUST_EXIST);
 564             if ($context->contextlevel != CONTEXT_COURSECAT and $context->contextlevel != CONTEXT_SYSTEM) {
 565                 throw new invalid_parameter_exception('Invalid context');
 566             }
 567             self::validate_context($context);
 568             if (!has_any_capability(array('moodle/cohort:manage', 'moodle/cohort:assign'), $context)) {
 569                 throw new required_capability_exception($context, 'moodle/cohort:assign', 'nopermissions', '');
 570             }
 571
 572             cohort_remove_member($cohort->id, $user->id);
 573         }
 574         $transaction->allow_commit();
 575     }
 576
 577     /**
 578      * Returns description of method result value
 579      *
 580      * @return null
 581      * @since Moodle 2.5
 582      */
 583     public static function delete_cohort_members_returns() {
 584         return null;
 585     }
 586
 587     /**
 588      * Returns description of method parameters
 589      *
 590      * @return external_function_parameters
 591      * @since Moodle 2.5
 592      */
 593     public static function get_cohort_members_parameters() {
 594         return new external_function_parameters(
 595             array(
 596                 'cohortids' => new external_multiple_structure(new external_value(PARAM_INT, 'Cohort ID')),
 597             )
 598         );
 599     }
 600
 601     /**
 602      * Return all members for a cohort
 603      *
 604      * @param array $cohortids array of cohort ids
 605      * @return array with cohort id keys containing arrays of user ids
 606      * @since Moodle 2.5
 607      */
 608     public static function get_cohort_members($cohortids) {
 609         global $DB;
 610         $params = self::validate_parameters(self::get_cohort_members_parameters(), array('cohortids' => $cohortids));
 611
 612         $members = array();
 613
 614         foreach ($params['cohortids'] as $cohortid) {
 615             // Validate params.
 616             $cohort = $DB->get_record('cohort', array('id' => $cohortid), '*', MUST_EXIST);
 617             // Now security checks.
 618             $context = context::instance_by_id($cohort->contextid, MUST_EXIST);
 619             if ($context->contextlevel != CONTEXT_COURSECAT and $context->contextlevel != CONTEXT_SYSTEM) {
 620                 throw new invalid_parameter_exception('Invalid context');
 621             }
 622             self::validate_context($context);
 623             if (!has_any_capability(array('moodle/cohort:manage', 'moodle/cohort:view'), $context)) {
 624                 throw new required_capability_exception($context, 'moodle/cohort:view', 'nopermissions', '');
 625             }
 626
 627             $cohortmembers = $DB->get_records_sql("SELECT u.id FROM {user} u, {cohort_members} cm
 628                 WHERE u.id = cm.userid AND cm.cohortid = ?
 629                 ORDER BY lastname ASC, firstname ASC", array($cohort->id));
 630             $members[] = array('cohortid' => $cohortid, 'userids' => array_keys($cohortmembers));
 631         }
 632         return $members;
 633     }
 634
 635     /**
 636      * Returns description of method result value
 637      *
 638      * @return external_description
 639      * @since Moodle 2.5
 640      */
 641     public static function get_cohort_members_returns() {
 642         return new external_multiple_structure(
 643             new external_single_structure(
 644                 array(
 645                     'cohortid' => new external_value(PARAM_INT, 'cohort record id'),
 646                     'userids' => new external_multiple_structure(new external_value(PARAM_INT, 'user id')),
 647                 )
 648             )
 649         );
 650     }
 651 }