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See Release Notes

  • Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
  • Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
  • PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.

Differences Between: [Versions 310 and 402] [Versions 311 and 402] [Versions 39 and 402] [Versions 400 and 402] [Versions 401 and 402]

   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  use core_external\external_api;
  18  use core_external\external_format_value;
  19  use core_external\external_function_parameters;
  20  use core_external\external_multiple_structure;
  21  use core_external\external_single_structure;
  22  use core_external\external_value;
  23  use core_external\external_warnings;
  24  use core_external\util;
  25  
  26  /**
  27   * External notes API
  28   *
  29   * @package    core_notes
  30   * @category   external
  31   * @copyright  2011 Jerome Mouneyrac
  32   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  33   */
  34  
  35  defined('MOODLE_INTERNAL') || die();
  36  
  37  require_once($CFG->dirroot . "/notes/lib.php");
  38  
  39  /**
  40   * Notes external functions
  41   *
  42   * @package    core_notes
  43   * @category   external
  44   * @copyright  2011 Jerome Mouneyrac
  45   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  46   * @since Moodle 2.2
  47   */
  48  class core_notes_external extends external_api {
  49  
  50      /**
  51       * Returns description of method parameters
  52       *
  53       * @return external_function_parameters
  54       * @since Moodle 2.2
  55       */
  56      public static function create_notes_parameters() {
  57          return new external_function_parameters(
  58              array(
  59                  'notes' => new external_multiple_structure(
  60                      new external_single_structure(
  61                          array(
  62                              'userid' => new external_value(PARAM_INT, 'id of the user the note is about'),
  63                              'publishstate' => new external_value(PARAM_ALPHA, '\'personal\', \'course\' or \'site\''),
  64                              'courseid' => new external_value(PARAM_INT, 'course id of the note (in Moodle a note can only be created into a course, even for site and personal notes)'),
  65                              'text' => new external_value(PARAM_RAW, 'the text of the message - text or HTML'),
  66                              'format' => new external_format_value('text', VALUE_DEFAULT),
  67                              'clientnoteid' => new external_value(PARAM_ALPHANUMEXT, 'your own client id for the note. If this id is provided, the fail message id will be returned to you', VALUE_OPTIONAL),
  68                          )
  69                      )
  70                  )
  71              )
  72          );
  73      }
  74  
  75      /**
  76       * Create notes about some users
  77       * Note: code should be matching the /notes/edit.php checks
  78       * and the /user/addnote.php checks. (they are similar cheks)
  79       *
  80       * @param array $notes  An array of notes to create.
  81       * @return array (success infos and fail infos)
  82       * @since Moodle 2.2
  83       */
  84      public static function create_notes($notes = array()) {
  85          global $CFG, $DB;
  86  
  87          $params = self::validate_parameters(self::create_notes_parameters(), array('notes' => $notes));
  88  
  89          // Check if note system is enabled.
  90          if (!$CFG->enablenotes) {
  91              throw new moodle_exception('notesdisabled', 'notes');
  92          }
  93  
  94          // Retrieve all courses.
  95          $courseids = array();
  96          foreach ($params['notes'] as $note) {
  97              $courseids[] = $note['courseid'];
  98          }
  99          $courses = $DB->get_records_list("course", "id", $courseids);
 100  
 101          // Retrieve all users of the notes.
 102          $userids = array();
 103          foreach ($params['notes'] as $note) {
 104              $userids[] = $note['userid'];
 105          }
 106          list($sqluserids, $sqlparams) = $DB->get_in_or_equal($userids, SQL_PARAMS_NAMED, 'userid_');
 107          $users = $DB->get_records_select("user", "id " . $sqluserids . " AND deleted = 0", $sqlparams);
 108  
 109          $resultnotes = array();
 110          foreach ($params['notes'] as $note) {
 111  
 112              $success = true;
 113              $resultnote = array(); // The infos about the success of the operation.
 114  
 115              // Check the course exists.
 116              if (empty($courses[$note['courseid']])) {
 117                  $success = false;
 118                  $errormessage = get_string('invalidcourseid', 'error');
 119              } else {
 120                  // Ensure the current user is allowed to run this function.
 121                  $context = context_course::instance($note['courseid']);
 122                  self::validate_context($context);
 123                  require_capability('moodle/notes:manage', $context);
 124              }
 125  
 126              // Check the user exists.
 127              if (empty($users[$note['userid']])) {
 128                  $success = false;
 129                  $errormessage = get_string('invaliduserid', 'notes', $note['userid']);
 130              }
 131  
 132              // Build the resultnote.
 133              if (isset($note['clientnoteid'])) {
 134                  $resultnote['clientnoteid'] = $note['clientnoteid'];
 135              }
 136  
 137              if ($success) {
 138                  // Now we can create the note.
 139                  $dbnote = new stdClass;
 140                  $dbnote->courseid = $note['courseid'];
 141                  $dbnote->userid = $note['userid'];
 142                  // Need to support 'html' and 'text' format values for backward compatibility.
 143                  switch (strtolower($note['format'])) {
 144                      case 'html':
 145                          $textformat = FORMAT_HTML;
 146                          break;
 147                      case 'text':
 148                          $textformat = FORMAT_PLAIN;
 149                      default:
 150                          $textformat = util::validate_format($note['format']);
 151                          break;
 152                  }
 153                  $dbnote->content = $note['text'];
 154                  $dbnote->format = $textformat;
 155  
 156                  // Get the state ('personal', 'course', 'site').
 157                  switch ($note['publishstate']) {
 158                      case 'personal':
 159                          $dbnote->publishstate = NOTES_STATE_DRAFT;
 160                          break;
 161                      case 'course':
 162                          $dbnote->publishstate = NOTES_STATE_PUBLIC;
 163                          break;
 164                      case 'site':
 165                          $dbnote->publishstate = NOTES_STATE_SITE;
 166                          $dbnote->courseid = SITEID;
 167                          break;
 168                      default:
 169                          break;
 170                  }
 171  
 172                  // TODO MDL-31119 performance improvement - if possible create a bulk functions for saving multiple notes at once
 173                  if (note_save($dbnote)) { // Note_save attribut an id in case of success.
 174                      $success = $dbnote->id;
 175                  }
 176  
 177                  $resultnote['noteid'] = $success;
 178              } else {
 179                  // WARNINGS: for backward compatibility we return this errormessage.
 180                  //          We should have thrown exceptions as these errors prevent results to be returned.
 181                  // See http://docs.moodle.org/dev/Errors_handling_in_web_services#When_to_send_a_warning_on_the_server_side .
 182                  $resultnote['noteid'] = -1;
 183                  $resultnote['errormessage'] = $errormessage;
 184              }
 185  
 186              $resultnotes[] = $resultnote;
 187          }
 188  
 189          return $resultnotes;
 190      }
 191  
 192      /**
 193       * Returns description of method result value
 194       *
 195       * @return \core_external\external_description
 196       * @since Moodle 2.2
 197       */
 198      public static function create_notes_returns() {
 199          return new external_multiple_structure(
 200              new external_single_structure(
 201                  array(
 202                      'clientnoteid' => new external_value(PARAM_ALPHANUMEXT, 'your own id for the note', VALUE_OPTIONAL),
 203                      'noteid' => new external_value(PARAM_INT, 'ID of the created note when successful, -1 when failed'),
 204                      'errormessage' => new external_value(PARAM_TEXT, 'error message - if failed', VALUE_OPTIONAL)
 205                  )
 206              )
 207          );
 208      }
 209  
 210      /**
 211       * Returns description of delete_notes parameters
 212       *
 213       * @return external_function_parameters
 214       * @since Moodle 2.5
 215       */
 216      public static function delete_notes_parameters() {
 217          return new external_function_parameters(
 218              array(
 219                  "notes"=> new external_multiple_structure(
 220                      new external_value(PARAM_INT, 'ID of the note to be deleted'), 'Array of Note Ids to be deleted.'
 221                  )
 222              )
 223          );
 224      }
 225  
 226      /**
 227       * Delete notes about users.
 228       * Note: code should be matching the /notes/delete.php checks.
 229       *
 230       * @param array $notes An array of ids for the notes to delete.
 231       * @return null
 232       * @since Moodle 2.5
 233       */
 234      public static function delete_notes($notes = array()) {
 235          global $CFG;
 236  
 237          $params = self::validate_parameters(self::delete_notes_parameters(), array('notes' => $notes));
 238  
 239          // Check if note system is enabled.
 240          if (!$CFG->enablenotes) {
 241              throw new moodle_exception('notesdisabled', 'notes');
 242          }
 243          $warnings = array();
 244          foreach ($params['notes'] as $noteid) {
 245              $note = note_load($noteid);
 246              if (isset($note->id)) {
 247                  // Ensure the current user is allowed to run this function.
 248                  $context = context_course::instance($note->courseid);
 249                  self::validate_context($context);
 250                  require_capability('moodle/notes:manage', $context);
 251                  note_delete($note);
 252              } else {
 253                  $warnings[] = array('item'=>'note', 'itemid'=>$noteid, 'warningcode'=>'badid', 'message'=>'Note does not exist');
 254              }
 255          }
 256          return $warnings;
 257      }
 258  
 259      /**
 260       * Returns description of delete_notes result value.
 261       *
 262       * @return \core_external\external_description
 263       * @since Moodle 2.5
 264       */
 265      public static function delete_notes_returns() {
 266          return  new external_warnings('item is always \'note\'',
 267                              'When errorcode is savedfailed the note could not be modified.' .
 268                              'When errorcode is badparam, an incorrect parameter was provided.' .
 269                              'When errorcode is badid, the note does not exist',
 270                              'errorcode can be badparam (incorrect parameter), savedfailed (could not be modified), or badid (note does not exist)');
 271  
 272      }
 273  
 274      /**
 275       * Returns description of get_notes parameters.
 276       *
 277       * @return external_function_parameters
 278       * @since Moodle 2.5
 279       */
 280      public static function get_notes_parameters() {
 281          return new external_function_parameters(
 282              array(
 283                  "notes"=> new external_multiple_structure(
 284                      new external_value(PARAM_INT, 'ID of the note to be retrieved'), 'Array of Note Ids to be retrieved.'
 285                  )
 286              )
 287          );
 288      }
 289  
 290      /**
 291       * Get notes about users.
 292       *
 293       * @param array $notes An array of ids for the notes to retrieve.
 294       * @return null
 295       * @since Moodle 2.5
 296       */
 297      public static function get_notes($notes) {
 298          global $CFG;
 299  
 300          $params = self::validate_parameters(self::get_notes_parameters(), array('notes' => $notes));
 301          // Check if note system is enabled.
 302          if (!$CFG->enablenotes) {
 303              throw new moodle_exception('notesdisabled', 'notes');
 304          }
 305          $resultnotes = array();
 306          foreach ($params['notes'] as $noteid) {
 307              $resultnote = array();
 308  
 309              $note = note_load($noteid);
 310              if (isset($note->id)) {
 311                  // Ensure the current user is allowed to run this function.
 312                  $context = context_course::instance($note->courseid);
 313                  self::validate_context($context);
 314                  require_capability('moodle/notes:view', $context);
 315                  list($gotnote['text'], $gotnote['format']) = util::format_text($note->content,
 316                                                                                    $note->format,
 317                                                                                    $context->id,
 318                                                                                    'notes',
 319                                                                                    '',
 320                                                                                    '');
 321                  $gotnote['noteid'] = $note->id;
 322                  $gotnote['userid'] = $note->userid;
 323                  $gotnote['publishstate'] = $note->publishstate;
 324                  $gotnote['courseid'] = $note->courseid;
 325                  $resultnotes["notes"][] = $gotnote;
 326              } else {
 327                  $resultnotes["warnings"][] = array('item' => 'note',
 328                                                     'itemid' => $noteid,
 329                                                     'warningcode' => 'badid',
 330                                                     'message' => 'Note does not exist');
 331              }
 332          }
 333          return $resultnotes;
 334      }
 335  
 336      /**
 337       * Returns description of get_notes result value.
 338       *
 339       * @return \core_external\external_description
 340       * @since Moodle 2.5
 341       */
 342      public static function get_notes_returns() {
 343          return new external_single_structure(
 344              array(
 345                  'notes' => new external_multiple_structure(
 346                      new external_single_structure(
 347                          array(
 348                              'noteid' => new external_value(PARAM_INT, 'id of the note', VALUE_OPTIONAL),
 349                              'userid' => new external_value(PARAM_INT, 'id of the user the note is about', VALUE_OPTIONAL),
 350                              'publishstate' => new external_value(PARAM_ALPHA, '\'personal\', \'course\' or \'site\'', VALUE_OPTIONAL),
 351                              'courseid' => new external_value(PARAM_INT, 'course id of the note', VALUE_OPTIONAL),
 352                              'text' => new external_value(PARAM_RAW, 'the text of the message - text or HTML', VALUE_OPTIONAL),
 353                              'format' => new external_format_value('text', VALUE_OPTIONAL),
 354                          ), 'note'
 355                      )
 356                   ),
 357                   'warnings' => new external_warnings('item is always \'note\'',
 358                          'When errorcode is savedfailed the note could not be modified.' .
 359                          'When errorcode is badparam, an incorrect parameter was provided.' .
 360                          'When errorcode is badid, the note does not exist',
 361                          'errorcode can be badparam (incorrect parameter), savedfailed (could not be modified), or badid (note does not exist)')
 362              )
 363          );
 364      }
 365  
 366      /**
 367       * Returns description of update_notes parameters.
 368       *
 369       * @return external_function_parameters
 370       * @since Moodle 2.5
 371       */
 372      public static function update_notes_parameters() {
 373          return new external_function_parameters(
 374              array(
 375                  'notes' => new external_multiple_structure(
 376                      new external_single_structure(
 377                          array(
 378                              'id' => new external_value(PARAM_INT, 'id of the note'),
 379                              'publishstate' => new external_value(PARAM_ALPHA, '\'personal\', \'course\' or \'site\''),
 380                              'text' => new external_value(PARAM_RAW, 'the text of the message - text or HTML'),
 381                              'format' => new external_format_value('text', VALUE_DEFAULT),
 382                          )
 383                      ), "Array of Notes", VALUE_DEFAULT, array()
 384                  )
 385              )
 386          );
 387      }
 388  
 389      /**
 390       * Update notes about users.
 391       *
 392       * @param array $notes An array of ids for the notes to update.
 393       * @return array fail infos.
 394       * @since Moodle 2.2
 395       */
 396      public static function update_notes($notes = array()) {
 397          global $CFG, $DB;
 398  
 399          $params = self::validate_parameters(self::update_notes_parameters(), array('notes' => $notes));
 400  
 401          // Check if note system is enabled.
 402          if (!$CFG->enablenotes) {
 403              throw new moodle_exception('notesdisabled', 'notes');
 404          }
 405  
 406          $warnings = array();
 407          foreach ($params['notes'] as $note) {
 408              $notedetails = note_load($note['id']);
 409              if (isset($notedetails->id)) {
 410                  // Ensure the current user is allowed to run this function.
 411                  $context = context_course::instance($notedetails->courseid);
 412                  self::validate_context($context);
 413                  require_capability('moodle/notes:manage', $context);
 414  
 415                  $dbnote = new stdClass;
 416                  $dbnote->id = $note['id'];
 417                  $dbnote->content = $note['text'];
 418                  $dbnote->format = util::validate_format($note['format']);
 419                  // Get the state ('personal', 'course', 'site').
 420                  switch ($note['publishstate']) {
 421                      case 'personal':
 422                          $dbnote->publishstate = NOTES_STATE_DRAFT;
 423                          break;
 424                      case 'course':
 425                          $dbnote->publishstate = NOTES_STATE_PUBLIC;
 426                          break;
 427                      case 'site':
 428                          $dbnote->publishstate = NOTES_STATE_SITE;
 429                          $dbnote->courseid = SITEID;
 430                          break;
 431                      default:
 432                          $warnings[] = array('item' => 'note',
 433                                              'itemid' => $note["id"],
 434                                              'warningcode' => 'badparam',
 435                                              'message' => 'Provided publishstate incorrect');
 436                          break;
 437                  }
 438                  if (!note_save($dbnote)) {
 439                      $warnings[] = array('item' => 'note',
 440                                          'itemid' => $note["id"],
 441                                          'warningcode' => 'savedfailed',
 442                                          'message' => 'Note could not be modified');
 443                  }
 444              } else {
 445                  $warnings[] = array('item' => 'note',
 446                                      'itemid' => $note["id"],
 447                                      'warningcode' => 'badid',
 448                                      'message' => 'Note does not exist');
 449              }
 450          }
 451          return $warnings;
 452      }
 453  
 454      /**
 455       * Returns description of update_notes result value.
 456       *
 457       * @return \core_external\external_description
 458       * @since Moodle 2.5
 459       */
 460      public static function update_notes_returns() {
 461          return new external_warnings('item is always \'note\'',
 462                              'When errorcode is savedfailed the note could not be modified.' .
 463                              'When errorcode is badparam, an incorrect parameter was provided.' .
 464                              'When errorcode is badid, the note does not exist',
 465                              'errorcode can be badparam (incorrect parameter), savedfailed (could not be modified), or badid (note does not exist)');
 466      }
 467  
 468      /**
 469       * Returns description of method parameters
 470       *
 471       * @return external_function_parameters
 472       * @since Moodle 2.9
 473       */
 474      public static function get_course_notes_parameters() {
 475          return new external_function_parameters(
 476              array(
 477                  'courseid' => new external_value(PARAM_INT, 'course id, 0 for SITE'),
 478                  'userid'   => new external_value(PARAM_INT, 'user id', VALUE_DEFAULT, 0),
 479              )
 480          );
 481      }
 482  
 483      /**
 484       * Create a notes list
 485       *
 486       * @param int $courseid ID of the Course
 487       * @param stdClass $context context object
 488       * @param int $userid ID of the User
 489       * @param int $state
 490       * @param int $author
 491       * @return array of notes
 492       * @since Moodle 2.9
 493       */
 494      protected static function create_note_list($courseid, $context, $userid, $state, $author = 0) {
 495          $results = [];
 496          $notes = note_list($courseid, $userid, $state, $author);
 497          foreach ($notes as $key => $note) {
 498              $note = (array)$note;
 499              [$note['content'], $note['format']] = util::format_text(
 500                  $note['content'],
 501                  $note['format'],
 502                  $context->id,
 503                  '',
 504                  '',
 505                  0
 506              );
 507              $results[$key] = $note;
 508          }
 509          return $results;
 510      }
 511  
 512      /**
 513       * Get a list of course notes
 514       *
 515       * @param int $courseid ID of the Course
 516       * @param int $userid ID of the User
 517       * @return array of site, course and personal notes and warnings
 518       * @since Moodle 2.9
 519       * @throws moodle_exception
 520       */
 521      public static function get_course_notes($courseid, $userid = 0) {
 522          global $CFG, $USER;
 523  
 524          if (empty($CFG->enablenotes)) {
 525              throw new moodle_exception('notesdisabled', 'notes');
 526          }
 527  
 528          $warnings = array();
 529          $arrayparams = array(
 530              'courseid' => $courseid,
 531              'userid'   => $userid,
 532          );
 533          $params = self::validate_parameters(self::get_course_notes_parameters(), $arrayparams);
 534  
 535          if (empty($params['courseid'])) {
 536              $params['courseid'] = SITEID;
 537          }
 538          $user = null;
 539          if (!empty($params['userid'])) {
 540              $user = core_user::get_user($params['userid'], '*', MUST_EXIST);
 541              core_user::require_active_user($user);
 542          }
 543  
 544          $course = get_course($params['courseid']);
 545  
 546          $systemcontext = context_system::instance();
 547          $canmanagesystemnotes = has_capability('moodle/notes:manage', $systemcontext);
 548  
 549          if ($course->id == SITEID) {
 550              $context = $systemcontext;
 551              $canmanagecoursenotes = $canmanagesystemnotes;
 552          } else {
 553              $context = context_course::instance($course->id);
 554              $canmanagecoursenotes = has_capability('moodle/notes:manage', $context);
 555          }
 556          self::validate_context($context);
 557  
 558          $sitenotes = array();
 559          $coursenotes = array();
 560          $personalnotes = array();
 561  
 562          if ($course->id != SITEID) {
 563  
 564              require_capability('moodle/notes:view', $context);
 565              $sitenotes = self::create_note_list(0, $systemcontext, $params['userid'], NOTES_STATE_SITE);
 566              $coursenotes = self::create_note_list($course->id, $context, $params['userid'], NOTES_STATE_PUBLIC);
 567              $personalnotes = self::create_note_list($course->id, $context, $params['userid'], NOTES_STATE_DRAFT,
 568                                                          $USER->id);
 569          } else {
 570              if (has_capability('moodle/notes:view', $context)) {
 571                  $sitenotes = self::create_note_list(0, $context, $params['userid'], NOTES_STATE_SITE);
 572              }
 573              // It returns notes only for a specific user!
 574              if (!empty($user)) {
 575                  $usercourses = enrol_get_users_courses($user->id, true);
 576                  foreach ($usercourses as $c) {
 577                      // All notes at course level, only if we have capability on every course.
 578                      if (has_capability('moodle/notes:view', context_course::instance($c->id))) {
 579                          $coursenotes += self::create_note_list($c->id, $context, $params['userid'], NOTES_STATE_PUBLIC);
 580                      }
 581                  }
 582              }
 583          }
 584  
 585          $results = array(
 586              'sitenotes'     => $sitenotes,
 587              'coursenotes'   => $coursenotes,
 588              'personalnotes' => $personalnotes,
 589              'canmanagesystemnotes' => $canmanagesystemnotes,
 590              'canmanagecoursenotes' => $canmanagecoursenotes,
 591              'warnings'      => $warnings
 592          );
 593          return $results;
 594  
 595      }
 596  
 597      /**
 598       * Returns array of note structure
 599       *
 600       * @return \core_external\external_description
 601       * @since Moodle 2.9
 602       */
 603      protected static function get_note_structure() {
 604          return array(
 605                       'id'           => new external_value(PARAM_INT, 'id of this note'),
 606                       'courseid'     => new external_value(PARAM_INT, 'id of the course'),
 607                       'userid'       => new external_value(PARAM_INT, 'user id'),
 608                       'content'      => new external_value(PARAM_RAW, 'the content text formated'),
 609                       'format'       => new external_format_value('content'),
 610                       'created'      => new external_value(PARAM_INT, 'time created (timestamp)'),
 611                       'lastmodified' => new external_value(PARAM_INT, 'time of last modification (timestamp)'),
 612                       'usermodified' => new external_value(PARAM_INT, 'user id of the creator of this note'),
 613                       'publishstate' => new external_value(PARAM_ALPHA, "state of the note (i.e. draft, public, site) ")
 614          );
 615      }
 616  
 617      /**
 618       * Returns description of method result value
 619       *
 620       * @return \core_external\external_description
 621       * @since Moodle 2.9
 622       */
 623      public static function get_course_notes_returns() {
 624          return new external_single_structure(
 625              array(
 626                  'sitenotes' => new external_multiple_structure(
 627                      new external_single_structure(self::get_note_structure() , ''), 'site notes', VALUE_OPTIONAL
 628                  ),
 629                  'coursenotes' => new external_multiple_structure(
 630                      new external_single_structure(self::get_note_structure() , ''), 'couse notes', VALUE_OPTIONAL
 631                  ),
 632                  'personalnotes' => new external_multiple_structure(
 633                      new external_single_structure(self::get_note_structure() , ''), 'personal notes', VALUE_OPTIONAL
 634                  ),
 635                  'canmanagesystemnotes' => new external_value(PARAM_BOOL, 'Whether the user can manage notes at system level.',
 636                      VALUE_OPTIONAL),
 637                  'canmanagecoursenotes' => new external_value(PARAM_BOOL, 'Whether the user can manage notes at the given course.',
 638                      VALUE_OPTIONAL),
 639                  'warnings' => new external_warnings()
 640              ), 'notes'
 641          );
 642      }
 643  
 644      /**
 645       * Returns description of method parameters
 646       *
 647       * @return external_function_parameters
 648       * @since Moodle 2.9
 649       */
 650      public static function view_notes_parameters() {
 651          return new external_function_parameters(
 652              array(
 653                  'courseid' => new external_value(PARAM_INT, 'course id, 0 for notes at system level'),
 654                  'userid' => new external_value(PARAM_INT, 'user id, 0 means view all the user notes', VALUE_DEFAULT, 0)
 655              )
 656          );
 657      }
 658  
 659      /**
 660       * Simulates the web interface view of notes/index.php: trigger events
 661       *
 662       * @param int $courseid id of the course
 663       * @param int $userid id of the user
 664       * @return array of warnings and status result
 665       * @since Moodle 2.9
 666       * @throws moodle_exception
 667       */
 668      public static function view_notes($courseid, $userid = 0) {
 669          global $CFG;
 670          require_once($CFG->dirroot . "/notes/lib.php");
 671  
 672          if (empty($CFG->enablenotes)) {
 673              throw new moodle_exception('notesdisabled', 'notes');
 674          }
 675  
 676          $warnings = array();
 677          $arrayparams = array(
 678              'courseid' => $courseid,
 679              'userid' => $userid
 680          );
 681          $params = self::validate_parameters(self::view_notes_parameters(), $arrayparams);
 682  
 683          if (empty($params['courseid'])) {
 684              $params['courseid'] = SITEID;
 685          }
 686  
 687          $course = get_course($params['courseid']);
 688  
 689          if ($course->id == SITEID) {
 690              $context = context_system::instance();
 691          } else {
 692              $context = context_course::instance($course->id);
 693          }
 694  
 695          // First of all, validate the context before do further permission checks.
 696          self::validate_context($context);
 697          require_capability('moodle/notes:view', $context);
 698  
 699          if (!empty($params['userid'])) {
 700              $user = core_user::get_user($params['userid'], '*', MUST_EXIST);
 701              core_user::require_active_user($user);
 702  
 703              if ($course->id != SITEID and !can_access_course($course, $user, '', true)) {
 704                  throw new moodle_exception('notenrolledprofile');
 705              }
 706          }
 707  
 708          note_view($context, $params['userid']);
 709  
 710          $result = array();
 711          $result['status'] = true;
 712          $result['warnings'] = $warnings;
 713          return $result;
 714  
 715      }
 716  
 717      /**
 718       * Returns description of method result value
 719       *
 720       * @return \core_external\external_description
 721       * @since Moodle 2.9
 722       */
 723      public static function view_notes_returns() {
 724          return new external_single_structure(
 725              array(
 726                  'status' => new external_value(PARAM_BOOL, 'status: true if success'),
 727                  'warnings' => new external_warnings()
 728              )
 729          );
 730      }
 731  
 732  }