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Differences Between: [Versions 310 and 402] [Versions 311 and 402] [Versions 39 and 402] [Versions 400 and 402] [Versions 401 and 402] [Versions 402 and 403]

   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   * This file contains classes used to manage the repository plugins in Moodle
  19   *
  20   * @since Moodle 2.0
  21   * @package   core_repository
  22   * @copyright 2009 Dongsheng Cai {@link http://dongsheng.org}
  23   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24   */
  25  
  26  defined('MOODLE_INTERNAL') || die();
  27  require_once($CFG->libdir . '/filelib.php');
  28  require_once($CFG->libdir . '/formslib.php');
  29  
  30  define('FILE_EXTERNAL',  1);
  31  define('FILE_INTERNAL',  2);
  32  define('FILE_REFERENCE', 4);
  33  define('FILE_CONTROLLED_LINK', 8);
  34  
  35  define('RENAME_SUFFIX', '_2');
  36  
  37  /**
  38   * This class is used to manage repository plugins
  39   *
  40   * A repository_type is a repository plug-in. It can be Box.net, Flick-r, ...
  41   * A repository type can be edited, sorted and hidden. It is mandatory for an
  42   * administrator to create a repository type in order to be able to create
  43   * some instances of this type.
  44   * Coding note:
  45   * - a repository_type object is mapped to the "repository" database table
  46   * - "typename" attibut maps the "type" database field. It is unique.
  47   * - general "options" for a repository type are saved in the config_plugin table
  48   * - when you delete a repository, all instances are deleted, and general
  49   *   options are also deleted from database
  50   * - When you create a type for a plugin that can't have multiple instances, a
  51   *   instance is automatically created.
  52   *
  53   * @package   core_repository
  54   * @copyright 2009 Jerome Mouneyrac
  55   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  56   */
  57  class repository_type implements cacheable_object {
  58  
  59  
  60      /**
  61       * Type name (no whitespace) - A type name is unique
  62       * Note: for a user-friendly type name see get_readablename()
  63       * @var String
  64       */
  65      private $_typename;
  66  
  67  
  68      /**
  69       * Options of this type
  70       * They are general options that any instance of this type would share
  71       * e.g. API key
  72       * These options are saved in config_plugin table
  73       * @var array
  74       */
  75      private $_options;
  76  
  77  
  78      /**
  79       * Is the repository type visible or hidden
  80       * If false (hidden): no instances can be created, edited, deleted, showned , used...
  81       * @var boolean
  82       */
  83      private $_visible;
  84  
  85  
  86      /**
  87       * 0 => not ordered, 1 => first position, 2 => second position...
  88       * A not order type would appear in first position (should never happened)
  89       * @var integer
  90       */
  91      private $_sortorder;
  92  
  93      /**
  94       * Return if the instance is visible in a context
  95       *
  96       * @todo check if the context visibility has been overwritten by the plugin creator
  97       *       (need to create special functions to be overvwritten in repository class)
  98       * @param stdClass $context context
  99       * @return bool
 100       */
 101      public function get_contextvisibility($context) {
 102          global $USER;
 103  
 104          if ($context->contextlevel == CONTEXT_COURSE) {
 105              return $this->_options['enablecourseinstances'];
 106          }
 107  
 108          if ($context->contextlevel == CONTEXT_USER) {
 109              return $this->_options['enableuserinstances'];
 110          }
 111  
 112          //the context is SITE
 113          return true;
 114      }
 115  
 116  
 117  
 118      /**
 119       * repository_type constructor
 120       *
 121       * @param int $typename
 122       * @param array $typeoptions
 123       * @param bool $visible
 124       * @param int $sortorder (don't really need set, it will be during create() call)
 125       */
 126      public function __construct($typename = '', $typeoptions = array(), $visible = true, $sortorder = 0) {
 127          global $CFG;
 128  
 129          //set type attributs
 130          $this->_typename = $typename;
 131          $this->_visible = $visible;
 132          $this->_sortorder = $sortorder;
 133  
 134          //set options attribut
 135          $this->_options = array();
 136          $options = repository::static_function($typename, 'get_type_option_names');
 137          //check that the type can be setup
 138          if (!empty($options)) {
 139              //set the type options
 140              foreach ($options as $config) {
 141                  if (array_key_exists($config, $typeoptions)) {
 142                      $this->_options[$config] = $typeoptions[$config];
 143                  }
 144              }
 145          }
 146  
 147          //retrieve visibility from option
 148          if (array_key_exists('enablecourseinstances',$typeoptions)) {
 149              $this->_options['enablecourseinstances'] = $typeoptions['enablecourseinstances'];
 150          } else {
 151               $this->_options['enablecourseinstances'] = 0;
 152          }
 153  
 154          if (array_key_exists('enableuserinstances',$typeoptions)) {
 155              $this->_options['enableuserinstances'] = $typeoptions['enableuserinstances'];
 156          } else {
 157               $this->_options['enableuserinstances'] = 0;
 158          }
 159  
 160      }
 161  
 162      /**
 163       * Get the type name (no whitespace)
 164       * For a human readable name, use get_readablename()
 165       *
 166       * @return string the type name
 167       */
 168      public function get_typename() {
 169          return $this->_typename;
 170      }
 171  
 172      /**
 173       * Return a human readable and user-friendly type name
 174       *
 175       * @return string user-friendly type name
 176       */
 177      public function get_readablename() {
 178          return get_string('pluginname','repository_'.$this->_typename);
 179      }
 180  
 181      /**
 182       * Return general options
 183       *
 184       * @return array the general options
 185       */
 186      public function get_options() {
 187          return $this->_options;
 188      }
 189  
 190      /**
 191       * Return visibility
 192       *
 193       * @return bool
 194       */
 195      public function get_visible() {
 196          return $this->_visible;
 197      }
 198  
 199      /**
 200       * Return order / position of display in the file picker
 201       *
 202       * @return int
 203       */
 204      public function get_sortorder() {
 205          return $this->_sortorder;
 206      }
 207  
 208      /**
 209       * Create a repository type (the type name must not already exist)
 210       * @param bool $silent throw exception?
 211       * @return mixed return int if create successfully, return false if
 212       */
 213      public function create($silent = false) {
 214          global $DB;
 215  
 216          //check that $type has been set
 217          $timmedtype = trim($this->_typename);
 218          if (empty($timmedtype)) {
 219              throw new repository_exception('emptytype', 'repository');
 220          }
 221  
 222          //set sortorder as the last position in the list
 223          if (!isset($this->_sortorder) || $this->_sortorder == 0 ) {
 224              $sql = "SELECT MAX(sortorder) FROM {repository}";
 225              $this->_sortorder = 1 + $DB->get_field_sql($sql);
 226          }
 227  
 228          //only create a new type if it doesn't already exist
 229          $existingtype = $DB->get_record('repository', array('type'=>$this->_typename));
 230          if (!$existingtype) {
 231              //create the type
 232              $newtype = new stdClass();
 233              $newtype->type = $this->_typename;
 234              $newtype->visible = $this->_visible;
 235              $newtype->sortorder = $this->_sortorder;
 236              $plugin_id = $DB->insert_record('repository', $newtype);
 237              //save the options in DB
 238              $this->update_options();
 239  
 240              $instanceoptionnames = repository::static_function($this->_typename, 'get_instance_option_names');
 241  
 242              //if the plugin type has no multiple instance (e.g. has no instance option name) so it wont
 243              //be possible for the administrator to create a instance
 244              //in this case we need to create an instance
 245              if (empty($instanceoptionnames)) {
 246                  $instanceoptions = array();
 247                  if (empty($this->_options['pluginname'])) {
 248                      // when moodle trying to install some repo plugin automatically
 249                      // this option will be empty, get it from language string when display
 250                      $instanceoptions['name'] = '';
 251                  } else {
 252                      // when admin trying to add a plugin manually, he will type a name
 253                      // for it
 254                      $instanceoptions['name'] = $this->_options['pluginname'];
 255                  }
 256                  repository::static_function($this->_typename, 'create', $this->_typename, 0, context_system::instance(), $instanceoptions);
 257              }
 258              //run plugin_init function
 259              if (!repository::static_function($this->_typename, 'plugin_init')) {
 260                  $this->update_visibility(false);
 261                  if (!$silent) {
 262                      throw new repository_exception('cannotinitplugin', 'repository');
 263                  }
 264              }
 265  
 266              cache::make('core', 'repositories')->purge();
 267              if(!empty($plugin_id)) {
 268                  // return plugin_id if create successfully
 269                  return $plugin_id;
 270              } else {
 271                  return false;
 272              }
 273  
 274          } else {
 275              if (!$silent) {
 276                  throw new repository_exception('existingrepository', 'repository');
 277              }
 278              // If plugin existed, return false, tell caller no new plugins were created.
 279              return false;
 280          }
 281      }
 282  
 283  
 284      /**
 285       * Update plugin options into the config_plugin table
 286       *
 287       * @param array $options
 288       * @return bool
 289       */
 290      public function update_options($options = null) {
 291          global $DB;
 292          $classname = 'repository_' . $this->_typename;
 293          $instanceoptions = repository::static_function($this->_typename, 'get_instance_option_names');
 294          if (empty($instanceoptions)) {
 295              // update repository instance name if this plugin type doesn't have muliti instances
 296              $params = array();
 297              $params['type'] = $this->_typename;
 298              $instances = repository::get_instances($params);
 299              $instance = array_pop($instances);
 300              if ($instance) {
 301                  $DB->set_field('repository_instances', 'name', $options['pluginname'], array('id'=>$instance->id));
 302              }
 303              unset($options['pluginname']);
 304          }
 305  
 306          if (!empty($options)) {
 307              $this->_options = $options;
 308          }
 309  
 310          foreach ($this->_options as $name => $value) {
 311              set_config($name, $value, $this->_typename);
 312          }
 313  
 314          cache::make('core', 'repositories')->purge();
 315          return true;
 316      }
 317  
 318      /**
 319       * Update visible database field with the value given as parameter
 320       * or with the visible value of this object
 321       * This function is private.
 322       * For public access, have a look to switch_and_update_visibility()
 323       *
 324       * @param bool $visible
 325       * @return bool
 326       */
 327      private function update_visible($visible = null) {
 328          global $DB;
 329  
 330          if (!empty($visible)) {
 331              $this->_visible = $visible;
 332          }
 333          else if (!isset($this->_visible)) {
 334              throw new repository_exception('updateemptyvisible', 'repository');
 335          }
 336  
 337          cache::make('core', 'repositories')->purge();
 338          return $DB->set_field('repository', 'visible', $this->_visible, array('type'=>$this->_typename));
 339      }
 340  
 341      /**
 342       * Update database sortorder field with the value given as parameter
 343       * or with the sortorder value of this object
 344       * This function is private.
 345       * For public access, have a look to move_order()
 346       *
 347       * @param int $sortorder
 348       * @return bool
 349       */
 350      private function update_sortorder($sortorder = null) {
 351          global $DB;
 352  
 353          if (!empty($sortorder) && $sortorder!=0) {
 354              $this->_sortorder = $sortorder;
 355          }
 356          //if sortorder is not set, we set it as the ;ast position in the list
 357          else if (!isset($this->_sortorder) || $this->_sortorder == 0 ) {
 358              $sql = "SELECT MAX(sortorder) FROM {repository}";
 359              $this->_sortorder = 1 + $DB->get_field_sql($sql);
 360          }
 361  
 362          cache::make('core', 'repositories')->purge();
 363          return $DB->set_field('repository', 'sortorder', $this->_sortorder, array('type'=>$this->_typename));
 364      }
 365  
 366      /**
 367       * Change order of the type with its adjacent upper or downer type
 368       * (database fields are updated)
 369       * Algorithm details:
 370       * 1. retrieve all types in an array. This array is sorted by sortorder,
 371       * and the array keys start from 0 to X (incremented by 1)
 372       * 2. switch sortorder values of this type and its adjacent type
 373       *
 374       * @param string $move "up" or "down"
 375       */
 376      public function move_order($move) {
 377          global $DB;
 378  
 379          $types = repository::get_types();    // retrieve all types
 380  
 381          // retrieve this type into the returned array
 382          $i = 0;
 383          while (!isset($indice) && $i<count($types)) {
 384              if ($types[$i]->get_typename() == $this->_typename) {
 385                  $indice = $i;
 386              }
 387              $i++;
 388          }
 389  
 390          // retrieve adjacent indice
 391          switch ($move) {
 392              case "up":
 393                  $adjacentindice = $indice - 1;
 394              break;
 395              case "down":
 396                  $adjacentindice = $indice + 1;
 397              break;
 398              default:
 399              throw new repository_exception('movenotdefined', 'repository');
 400          }
 401  
 402          //switch sortorder of this type and the adjacent type
 403          //TODO: we could reset sortorder for all types. This is not as good in performance term, but
 404          //that prevent from wrong behaviour on a screwed database. As performance are not important in this particular case
 405          //it worth to change the algo.
 406          if ($adjacentindice>=0 && !empty($types[$adjacentindice])) {
 407              $DB->set_field('repository', 'sortorder', $this->_sortorder, array('type'=>$types[$adjacentindice]->get_typename()));
 408              $this->update_sortorder($types[$adjacentindice]->get_sortorder());
 409          }
 410      }
 411  
 412      /**
 413       * 1. Change visibility to the value chosen
 414       * 2. Update the type
 415       *
 416       * @param bool $visible
 417       * @return bool
 418       */
 419      public function update_visibility($visible = null) {
 420          if (is_bool($visible)) {
 421              $this->_visible = $visible;
 422          } else {
 423              $this->_visible = !$this->_visible;
 424          }
 425          return $this->update_visible();
 426      }
 427  
 428  
 429      /**
 430       * Delete a repository_type (general options are removed from config_plugin
 431       * table, and all instances are deleted)
 432       *
 433       * @param bool $downloadcontents download external contents if exist
 434       * @return bool
 435       */
 436      public function delete($downloadcontents = false) {
 437          global $DB;
 438  
 439          //delete all instances of this type
 440          $params = array();
 441          $params['context'] = array();
 442          $params['onlyvisible'] = false;
 443          $params['type'] = $this->_typename;
 444          $instances = repository::get_instances($params);
 445          foreach ($instances as $instance) {
 446              $instance->delete($downloadcontents);
 447          }
 448  
 449          //delete all general options
 450          foreach ($this->_options as $name => $value) {
 451              set_config($name, null, $this->_typename);
 452          }
 453  
 454          cache::make('core', 'repositories')->purge();
 455          try {
 456              $DB->delete_records('repository', array('type' => $this->_typename));
 457          } catch (dml_exception $ex) {
 458              return false;
 459          }
 460          return true;
 461      }
 462  
 463      /**
 464       * Prepares the repository type to be cached. Implements method from cacheable_object interface.
 465       *
 466       * @return array
 467       */
 468      public function prepare_to_cache() {
 469          return array(
 470              'typename' => $this->_typename,
 471              'typeoptions' => $this->_options,
 472              'visible' => $this->_visible,
 473              'sortorder' => $this->_sortorder
 474          );
 475      }
 476  
 477      /**
 478       * Restores repository type from cache. Implements method from cacheable_object interface.
 479       *
 480       * @return array
 481       */
 482      public static function wake_from_cache($data) {
 483          return new repository_type($data['typename'], $data['typeoptions'], $data['visible'], $data['sortorder']);
 484      }
 485  }
 486  
 487  /**
 488   * This is the base class of the repository class.
 489   *
 490   * To create repository plugin, see: {@link https://moodledev.io/docs/apis/plugintypes/repository}
 491   * See an example: repository_dropbox
 492   *
 493   * @package   core_repository
 494   * @copyright 2009 Dongsheng Cai {@link http://dongsheng.org}
 495   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 496   */
 497  abstract class repository implements cacheable_object {
 498      /**
 499       * Timeout in seconds for downloading the external file into moodle
 500       * @deprecated since Moodle 2.7, please use $CFG->repositorygetfiletimeout instead
 501       */
 502      const GETFILE_TIMEOUT = 30;
 503  
 504      /**
 505       * Timeout in seconds for syncronising the external file size
 506       * @deprecated since Moodle 2.7, please use $CFG->repositorysyncfiletimeout instead
 507       */
 508      const SYNCFILE_TIMEOUT = 1;
 509  
 510      /**
 511       * Timeout in seconds for downloading an image file from external repository during syncronisation
 512       * @deprecated since Moodle 2.7, please use $CFG->repositorysyncimagetimeout instead
 513       */
 514      const SYNCIMAGE_TIMEOUT = 3;
 515  
 516      // $disabled can be set to true to disable a plugin by force
 517      // example: self::$disabled = true
 518      /** @var bool force disable repository instance */
 519      public $disabled = false;
 520      /** @var int repository instance id */
 521      public $id;
 522      /** @var context current context */
 523      public $context;
 524      /** @var array repository options */
 525      public $options;
 526      /** @var bool Whether or not the repository instance is editable */
 527      public $readonly;
 528      /** @var int return types */
 529      public $returntypes;
 530      /** @var stdClass repository instance database record */
 531      public $instance;
 532      /** @var string Type of repository (webdav, google_docs, dropbox, ...). Read from $this->get_typename(). */
 533      protected $typename;
 534      /** @var string instance name. */
 535      public $name;
 536      /** @var bool true if the super construct is called, otherwise false. */
 537      public $super_called;
 538  
 539      /**
 540       * Constructor
 541       *
 542       * @param int $repositoryid repository instance id
 543       * @param int|stdClass $context a context id or context object
 544       * @param array $options repository options
 545       * @param int $readonly indicate this repo is readonly or not
 546       */
 547      public function __construct($repositoryid, $context = SYSCONTEXTID, $options = array(), $readonly = 0) {
 548          global $DB;
 549          $this->id = $repositoryid;
 550          if (is_object($context)) {
 551              $this->context = $context;
 552          } else {
 553              $this->context = context::instance_by_id($context);
 554          }
 555          $cache = cache::make('core', 'repositories');
 556          if (($this->instance = $cache->get('i:'. $this->id)) === false) {
 557              $this->instance = $DB->get_record_sql("SELECT i.*, r.type AS repositorytype, r.sortorder, r.visible
 558                        FROM {repository} r, {repository_instances} i
 559                       WHERE i.typeid = r.id and i.id = ?", array('id' => $this->id));
 560              $cache->set('i:'. $this->id, $this->instance);
 561          }
 562          $this->readonly = $readonly;
 563          $this->options = array();
 564  
 565          if (is_array($options)) {
 566              // The get_option() method will get stored options in database.
 567              $options = array_merge($this->get_option(), $options);
 568          } else {
 569              $options = $this->get_option();
 570          }
 571          foreach ($options as $n => $v) {
 572              $this->options[$n] = $v;
 573          }
 574          $this->name = $this->get_name();
 575          $this->returntypes = $this->supported_returntypes();
 576          $this->super_called = true;
 577      }
 578  
 579      /**
 580       * Get repository instance using repository id
 581       *
 582       * Note that this function does not check permission to access repository contents
 583       *
 584       * @throws repository_exception
 585       *
 586       * @param int $repositoryid repository instance ID
 587       * @param context|int $context context instance or context ID where this repository will be used
 588       * @param array $options additional repository options
 589       * @return repository
 590       */
 591      public static function get_repository_by_id($repositoryid, $context, $options = array()) {
 592          global $CFG, $DB;
 593          $cache = cache::make('core', 'repositories');
 594          if (!is_object($context)) {
 595              $context = context::instance_by_id($context);
 596          }
 597          $cachekey = 'rep:'. $repositoryid. ':'. $context->id. ':'. serialize($options);
 598          if ($repository = $cache->get($cachekey)) {
 599              return $repository;
 600          }
 601  
 602          if (!$record = $cache->get('i:'. $repositoryid)) {
 603              $sql = "SELECT i.*, r.type AS repositorytype, r.visible, r.sortorder
 604                        FROM {repository_instances} i
 605                        JOIN {repository} r ON r.id = i.typeid
 606                       WHERE i.id = ?";
 607              if (!$record = $DB->get_record_sql($sql, array($repositoryid))) {
 608                  throw new repository_exception('invalidrepositoryid', 'repository');
 609              }
 610              $cache->set('i:'. $record->id, $record);
 611          }
 612  
 613          $type = $record->repositorytype;
 614          if (file_exists($CFG->dirroot . "/repository/$type/lib.php")) {
 615              require_once($CFG->dirroot . "/repository/$type/lib.php");
 616              $classname = 'repository_' . $type;
 617              $options['type'] = $type;
 618              $options['typeid'] = $record->typeid;
 619              $options['visible'] = $record->visible;
 620              if (empty($options['name'])) {
 621                  $options['name'] = $record->name;
 622              }
 623              $repository = new $classname($repositoryid, $context, $options, $record->readonly);
 624              if (empty($repository->super_called)) {
 625                  // to make sure the super construct is called
 626                  debugging('parent::__construct must be called by '.$type.' plugin.');
 627              }
 628              $cache->set($cachekey, $repository);
 629              return $repository;
 630          } else {
 631              throw new repository_exception('invalidplugin', 'repository');
 632          }
 633      }
 634  
 635      /**
 636       * Returns the type name of the repository.
 637       *
 638       * @return string type name of the repository.
 639       * @since  Moodle 2.5
 640       */
 641      public function get_typename() {
 642          if (empty($this->typename)) {
 643              $matches = array();
 644              if (!preg_match("/^repository_(.*)$/", get_class($this), $matches)) {
 645                  throw new coding_exception('The class name of a repository should be repository_<typeofrepository>, '.
 646                          'e.g. repository_dropbox');
 647              }
 648              $this->typename = $matches[1];
 649          }
 650          return $this->typename;
 651      }
 652  
 653      /**
 654       * Get a repository type object by a given type name.
 655       *
 656       * @static
 657       * @param string $typename the repository type name
 658       * @return repository_type|bool
 659       */
 660      public static function get_type_by_typename($typename) {
 661          global $DB;
 662          $cache = cache::make('core', 'repositories');
 663          if (($repositorytype = $cache->get('typename:'. $typename)) === false) {
 664              $repositorytype = null;
 665              if ($record = $DB->get_record('repository', array('type' => $typename))) {
 666                  $repositorytype = new repository_type($record->type, (array)get_config($record->type), $record->visible, $record->sortorder);
 667                  $cache->set('typeid:'. $record->id, $repositorytype);
 668              }
 669              $cache->set('typename:'. $typename, $repositorytype);
 670          }
 671          return $repositorytype;
 672      }
 673  
 674      /**
 675       * Get the repository type by a given repository type id.
 676       *
 677       * @static
 678       * @param int $id the type id
 679       * @return object
 680       */
 681      public static function get_type_by_id($id) {
 682          global $DB;
 683          $cache = cache::make('core', 'repositories');
 684          if (($repositorytype = $cache->get('typeid:'. $id)) === false) {
 685              $repositorytype = null;
 686              if ($record = $DB->get_record('repository', array('id' => $id))) {
 687                  $repositorytype = new repository_type($record->type, (array)get_config($record->type), $record->visible, $record->sortorder);
 688                  $cache->set('typename:'. $record->type, $repositorytype);
 689              }
 690              $cache->set('typeid:'. $id, $repositorytype);
 691          }
 692          return $repositorytype;
 693      }
 694  
 695      /**
 696       * Return all repository types ordered by sortorder field
 697       * first repository type in returnedarray[0], second repository type in returnedarray[1], ...
 698       *
 699       * @static
 700       * @param bool $visible can return types by visiblity, return all types if null
 701       * @return array Repository types
 702       */
 703      public static function get_types($visible=null) {
 704          global $DB, $CFG;
 705          $cache = cache::make('core', 'repositories');
 706          if (!$visible) {
 707              $typesnames = $cache->get('types');
 708          } else {
 709              $typesnames = $cache->get('typesvis');
 710          }
 711          $types = array();
 712          if ($typesnames === false) {
 713              $typesnames = array();
 714              $vistypesnames = array();
 715              if ($records = $DB->get_records('repository', null ,'sortorder')) {
 716                  foreach($records as $type) {
 717                      if (($repositorytype = $cache->get('typename:'. $type->type)) === false) {
 718                          // Create new instance of repository_type.
 719                          if (file_exists($CFG->dirroot . '/repository/'. $type->type .'/lib.php')) {
 720                              $repositorytype = new repository_type($type->type, (array)get_config($type->type), $type->visible, $type->sortorder);
 721                              $cache->set('typeid:'. $type->id, $repositorytype);
 722                              $cache->set('typename:'. $type->type, $repositorytype);
 723                          }
 724                      }
 725                      if ($repositorytype) {
 726                          if (empty($visible) || $repositorytype->get_visible()) {
 727                              $types[] = $repositorytype;
 728                              $vistypesnames[] = $repositorytype->get_typename();
 729                          }
 730                          $typesnames[] = $repositorytype->get_typename();
 731                      }
 732                  }
 733              }
 734              $cache->set('types', $typesnames);
 735              $cache->set('typesvis', $vistypesnames);
 736          } else {
 737              foreach ($typesnames as $typename) {
 738                  $types[] = self::get_type_by_typename($typename);
 739              }
 740          }
 741          return $types;
 742      }
 743  
 744      /**
 745       * Checks if user has a capability to view the current repository.
 746       *
 747       * @return bool true when the user can, otherwise throws an exception.
 748       * @throws repository_exception when the user does not meet the requirements.
 749       */
 750      public final function check_capability() {
 751          global $USER;
 752  
 753          // The context we are on.
 754          $currentcontext = $this->context;
 755  
 756          // Ensure that the user can view the repository in the current context.
 757          $can = has_capability('repository/'.$this->get_typename().':view', $currentcontext);
 758  
 759          // Context in which the repository has been created.
 760          $repocontext = context::instance_by_id($this->instance->contextid);
 761  
 762          // Prevent access to private repositories when logged in as.
 763          if ($can && \core\session\manager::is_loggedinas()) {
 764              if ($this->contains_private_data() || $repocontext->contextlevel == CONTEXT_USER) {
 765                  $can = false;
 766              }
 767          }
 768  
 769          // We are going to ensure that the current context was legit, and reliable to check
 770          // the capability against. (No need to do that if we already cannot).
 771          if ($can) {
 772              if ($repocontext->contextlevel == CONTEXT_USER) {
 773                  // The repository is a user instance, ensure we're the right user to access it!
 774                  if ($repocontext->instanceid != $USER->id) {
 775                      $can = false;
 776                  }
 777              } else if ($repocontext->contextlevel == CONTEXT_COURSE) {
 778                  // The repository is a course one. Let's check that we are on the right course.
 779                  if (in_array($currentcontext->contextlevel, array(CONTEXT_COURSE, CONTEXT_MODULE, CONTEXT_BLOCK))) {
 780                      $coursecontext = $currentcontext->get_course_context();
 781                      if ($coursecontext->instanceid != $repocontext->instanceid) {
 782                          $can = false;
 783                      }
 784                  } else {
 785                      // We are on a parent context, therefore it's legit to check the permissions
 786                      // in the current context.
 787                  }
 788              } else {
 789                  // Nothing to check here, system instances can have different permissions on different
 790                  // levels. We do not want to prevent URL hack here, because it does not make sense to
 791                  // prevent a user to access a repository in a context if it's accessible in another one.
 792              }
 793          }
 794  
 795          if ($can) {
 796              return true;
 797          }
 798  
 799          throw new repository_exception('nopermissiontoaccess', 'repository');
 800      }
 801  
 802      /**
 803       * Check if file already exists in draft area.
 804       *
 805       * @static
 806       * @param int $itemid of the draft area.
 807       * @param string $filepath path to the file.
 808       * @param string $filename file name.
 809       * @return bool
 810       */
 811      public static function draftfile_exists($itemid, $filepath, $filename) {
 812          global $USER;
 813          $fs = get_file_storage();
 814          $usercontext = context_user::instance($USER->id);
 815          return $fs->file_exists($usercontext->id, 'user', 'draft', $itemid, $filepath, $filename);
 816      }
 817  
 818      /**
 819       * Parses the moodle file reference and returns an instance of stored_file
 820       *
 821       * @param string $reference reference to the moodle internal file as retruned by
 822       *        {@link repository::get_file_reference()} or {@link file_storage::pack_reference()}
 823       * @return stored_file|null
 824       */
 825      public static function get_moodle_file($reference) {
 826          $params = file_storage::unpack_reference($reference, true);
 827          $fs = get_file_storage();
 828          return $fs->get_file($params['contextid'], $params['component'], $params['filearea'],
 829                      $params['itemid'], $params['filepath'], $params['filename']);
 830      }
 831  
 832      /**
 833       * Repository method to make sure that user can access particular file.
 834       *
 835       * This is checked when user tries to pick the file from repository to deal with
 836       * potential parameter substitutions is request
 837       *
 838       * @param string $source source of the file, returned by repository as 'source' and received back from user (not cleaned)
 839       * @return bool whether the file is accessible by current user
 840       */
 841      public function file_is_accessible($source) {
 842          if ($this->has_moodle_files()) {
 843              $reference = $this->get_file_reference($source);
 844              try {
 845                  $params = file_storage::unpack_reference($reference, true);
 846              } catch (file_reference_exception $e) {
 847                  return false;
 848              }
 849              $browser = get_file_browser();
 850              $context = context::instance_by_id($params['contextid']);
 851              $file_info = $browser->get_file_info($context, $params['component'], $params['filearea'],
 852                      $params['itemid'], $params['filepath'], $params['filename']);
 853              return !empty($file_info);
 854          }
 855          return true;
 856      }
 857  
 858      /**
 859       * This function is used to copy a moodle file to draft area.
 860       *
 861       * It DOES NOT check if the user is allowed to access this file because the actual file
 862       * can be located in the area where user does not have access to but there is an alias
 863       * to this file in the area where user CAN access it.
 864       * {@link file_is_accessible} should be called for alias location before calling this function.
 865       *
 866       * @param string $source The metainfo of file, it is base64 encoded php serialized data
 867       * @param stdClass|array $filerecord contains itemid, filepath, filename and optionally other
 868       *      attributes of the new file
 869       * @param int $maxbytes maximum allowed size of file, -1 if unlimited. If size of file exceeds
 870       *      the limit, the file_exception is thrown.
 871       * @param int $areamaxbytes the maximum size of the area. A file_exception is thrown if the
 872       *      new file will reach the limit.
 873       * @return array The information about the created file
 874       */
 875      public function copy_to_area($source, $filerecord, $maxbytes = -1, $areamaxbytes = FILE_AREA_MAX_BYTES_UNLIMITED) {
 876          global $USER;
 877          $fs = get_file_storage();
 878  
 879          if ($this->has_moodle_files() == false) {
 880              throw new coding_exception('Only repository used to browse moodle files can use repository::copy_to_area()');
 881          }
 882  
 883          $user_context = context_user::instance($USER->id);
 884  
 885          $filerecord = (array)$filerecord;
 886          // make sure the new file will be created in user draft area
 887          $filerecord['component'] = 'user';
 888          $filerecord['filearea'] = 'draft';
 889          $filerecord['contextid'] = $user_context->id;
 890          $draftitemid = $filerecord['itemid'];
 891          $new_filepath = $filerecord['filepath'];
 892          $new_filename = $filerecord['filename'];
 893  
 894          // the file needs to copied to draft area
 895          $stored_file = self::get_moodle_file($source);
 896          if ($maxbytes != -1 && $stored_file->get_filesize() > $maxbytes) {
 897              $maxbytesdisplay = display_size($maxbytes, 0);
 898              throw new file_exception('maxbytesfile', (object) array('file' => $filerecord['filename'],
 899                                                                      'size' => $maxbytesdisplay));
 900          }
 901          // Validate the size of the draft area.
 902          if (file_is_draft_area_limit_reached($draftitemid, $areamaxbytes, $stored_file->get_filesize())) {
 903              throw new file_exception('maxareabytes');
 904          }
 905  
 906          if (repository::draftfile_exists($draftitemid, $new_filepath, $new_filename)) {
 907              // create new file
 908              $unused_filename = repository::get_unused_filename($draftitemid, $new_filepath, $new_filename);
 909              $filerecord['filename'] = $unused_filename;
 910              $fs->create_file_from_storedfile($filerecord, $stored_file);
 911              $event = array();
 912              $event['event'] = 'fileexists';
 913              $event['newfile'] = new stdClass;
 914              $event['newfile']->filepath = $new_filepath;
 915              $event['newfile']->filename = $unused_filename;
 916              $event['newfile']->url = moodle_url::make_draftfile_url($draftitemid, $new_filepath, $unused_filename)->out();
 917              $event['existingfile'] = new stdClass;
 918              $event['existingfile']->filepath = $new_filepath;
 919              $event['existingfile']->filename = $new_filename;
 920              $event['existingfile']->url = moodle_url::make_draftfile_url($draftitemid, $new_filepath, $new_filename)->out();
 921              return $event;
 922          } else {
 923              $fs->create_file_from_storedfile($filerecord, $stored_file);
 924              $info = array();
 925              $info['itemid'] = $draftitemid;
 926              $info['file'] = $new_filename;
 927              $info['title'] = $new_filename;
 928              $info['contextid'] = $user_context->id;
 929              $info['url'] = moodle_url::make_draftfile_url($draftitemid, $new_filepath, $new_filename)->out();
 930              $info['filesize'] = $stored_file->get_filesize();
 931              return $info;
 932          }
 933      }
 934  
 935      /**
 936       * Get an unused filename from the current draft area.
 937       *
 938       * Will check if the file ends with ([0-9]) and increase the number.
 939       *
 940       * @static
 941       * @param int $itemid draft item ID.
 942       * @param string $filepath path to the file.
 943       * @param string $filename name of the file.
 944       * @return string an unused file name.
 945       */
 946      public static function get_unused_filename($itemid, $filepath, $filename) {
 947          global $USER;
 948          $contextid = context_user::instance($USER->id)->id;
 949          $fs = get_file_storage();
 950          return $fs->get_unused_filename($contextid, 'user', 'draft', $itemid, $filepath, $filename);
 951      }
 952  
 953      /**
 954       * Append a suffix to filename.
 955       *
 956       * @static
 957       * @param string $filename
 958       * @return string
 959       * @deprecated since 2.5
 960       */
 961      public static function append_suffix($filename) {
 962          debugging('The function repository::append_suffix() has been deprecated. Use repository::get_unused_filename() instead.',
 963              DEBUG_DEVELOPER);
 964          $pathinfo = pathinfo($filename);
 965          if (empty($pathinfo['extension'])) {
 966              return $filename . RENAME_SUFFIX;
 967          } else {
 968              return $pathinfo['filename'] . RENAME_SUFFIX . '.' . $pathinfo['extension'];
 969          }
 970      }
 971  
 972      /**
 973       * Return all types that you a user can create/edit and which are also visible
 974       * Note: Mostly used in order to know if at least one editable type can be set
 975       *
 976       * @static
 977       * @param stdClass $context the context for which we want the editable types
 978       * @return array types
 979       */
 980      public static function get_editable_types($context = null) {
 981  
 982          if (empty($context)) {
 983              $context = context_system::instance();
 984          }
 985  
 986          $types= repository::get_types(true);
 987          $editabletypes = array();
 988          foreach ($types as $type) {
 989              $instanceoptionnames = repository::static_function($type->get_typename(), 'get_instance_option_names');
 990              if (!empty($instanceoptionnames)) {
 991                  if ($type->get_contextvisibility($context)) {
 992                      $editabletypes[]=$type;
 993                  }
 994               }
 995          }
 996          return $editabletypes;
 997      }
 998  
 999      /**
1000       * Return repository instances
1001       *
1002       * @static
1003       * @param array $args Array containing the following keys:
1004       *           currentcontext : instance of context (default system context)
1005       *           context : array of instances of context (default empty array)
1006       *           onlyvisible : bool (default true)
1007       *           type : string return instances of this type only
1008       *           accepted_types : string|array return instances that contain files of those types (*, web_image, .pdf, ...)
1009       *           return_types : int combination of FILE_INTERNAL & FILE_EXTERNAL & FILE_REFERENCE & FILE_CONTROLLED_LINK.
1010       *                          0 means every type. The default is FILE_INTERNAL | FILE_EXTERNAL.
1011       *           userid : int if specified, instances belonging to other users will not be returned
1012       *
1013       * @return array repository instances
1014       */
1015      public static function get_instances($args = array()) {
1016          global $DB, $CFG, $USER;
1017  
1018          // Fill $args attributes with default values unless specified
1019          if (isset($args['currentcontext'])) {
1020              if ($args['currentcontext'] instanceof context) {
1021                  $current_context = $args['currentcontext'];
1022              } else {
1023                  debugging('currentcontext passed to repository::get_instances was ' .
1024                          'not a context object. Using system context instead, but ' .
1025                          'you should probably fix your code.', DEBUG_DEVELOPER);
1026                  $current_context = context_system::instance();
1027              }
1028          } else {
1029              $current_context = context_system::instance();
1030          }
1031          $args['currentcontext'] = $current_context->id;
1032          $contextids = array();
1033          if (!empty($args['context'])) {
1034              foreach ($args['context'] as $context) {
1035                  $contextids[] = $context->id;
1036              }
1037          }
1038          $args['context'] = $contextids;
1039          if (!isset($args['onlyvisible'])) {
1040              $args['onlyvisible'] = true;
1041          }
1042          if (!isset($args['return_types'])) {
1043              $args['return_types'] = FILE_INTERNAL | FILE_EXTERNAL;
1044          }
1045          if (!isset($args['type'])) {
1046              $args['type'] = null;
1047          }
1048          if (empty($args['disable_types']) || !is_array($args['disable_types'])) {
1049              $args['disable_types'] = null;
1050          }
1051          if (empty($args['userid']) || !is_numeric($args['userid'])) {
1052              $args['userid'] = null;
1053          }
1054          if (!isset($args['accepted_types']) || (is_array($args['accepted_types']) && in_array('*', $args['accepted_types']))) {
1055              $args['accepted_types'] = '*';
1056          }
1057          ksort($args);
1058          $cachekey = 'all:'. serialize($args);
1059  
1060          // Check if we have cached list of repositories with the same query
1061          $cache = cache::make('core', 'repositories');
1062          if (($cachedrepositories = $cache->get($cachekey)) !== false) {
1063              // convert from cacheable_object_array to array
1064              $repositories = array();
1065              foreach ($cachedrepositories as $repository) {
1066                  $repositories[$repository->id] = $repository;
1067              }
1068              return $repositories;
1069          }
1070  
1071          // Prepare DB SQL query to retrieve repositories
1072          $params = array();
1073          $sql = "SELECT i.*, r.type AS repositorytype, r.sortorder, r.visible
1074                    FROM {repository} r, {repository_instances} i
1075                   WHERE i.typeid = r.id ";
1076  
1077          if ($args['disable_types']) {
1078              list($types, $p) = $DB->get_in_or_equal($args['disable_types'], SQL_PARAMS_NAMED, 'distype', false);
1079              $sql .= " AND r.type $types";
1080              $params = array_merge($params, $p);
1081          }
1082  
1083          if ($args['userid']) {
1084              $sql .= " AND (i.userid = 0 or i.userid = :userid)";
1085              $params['userid'] = $args['userid'];
1086          }
1087  
1088          if ($args['context']) {
1089              list($ctxsql, $p2) = $DB->get_in_or_equal($args['context'], SQL_PARAMS_NAMED, 'ctx');
1090              $sql .= " AND i.contextid $ctxsql";
1091              $params = array_merge($params, $p2);
1092          }
1093  
1094          if ($args['onlyvisible'] == true) {
1095              $sql .= " AND r.visible = 1";
1096          }
1097  
1098          if ($args['type'] !== null) {
1099              $sql .= " AND r.type = :type";
1100              $params['type'] = $args['type'];
1101          }
1102          $sql .= " ORDER BY r.sortorder, i.name";
1103  
1104          if (!$records = $DB->get_records_sql($sql, $params)) {
1105              $records = array();
1106          }
1107  
1108          $repositories = array();
1109          // Sortorder should be unique, which is not true if we use $record->sortorder
1110          // and there are multiple instances of any repository type
1111          $sortorder = 1;
1112          foreach ($records as $record) {
1113              $cache->set('i:'. $record->id, $record);
1114              if (!file_exists($CFG->dirroot . '/repository/'. $record->repositorytype.'/lib.php')) {
1115                  continue;
1116              }
1117              $repository = self::get_repository_by_id($record->id, $current_context);
1118              $repository->options['sortorder'] = $sortorder++;
1119  
1120              $is_supported = true;
1121  
1122              // check mimetypes
1123              if ($args['accepted_types'] !== '*' and $repository->supported_filetypes() !== '*') {
1124                  $accepted_ext = file_get_typegroup('extension', $args['accepted_types']);
1125                  $supported_ext = file_get_typegroup('extension', $repository->supported_filetypes());
1126                  $valid_ext = array_intersect($accepted_ext, $supported_ext);
1127                  $is_supported = !empty($valid_ext);
1128              }
1129              // Check return values.
1130              if (!empty($args['return_types']) && !($repository->supported_returntypes() & $args['return_types'])) {
1131                  $is_supported = false;
1132              }
1133  
1134              if (!$args['onlyvisible'] || ($repository->is_visible() && !$repository->disabled)) {
1135                  // check capability in current context
1136                  $capability = has_capability('repository/'.$record->repositorytype.':view', $current_context);
1137                  if ($record->repositorytype == 'coursefiles') {
1138                      // coursefiles plugin needs managefiles permission
1139                      $capability = $capability && has_capability('moodle/course:managefiles', $current_context);
1140                  }
1141                  if ($is_supported && $capability) {
1142                      $repositories[$repository->id] = $repository;
1143                  }
1144              }
1145          }
1146          $cache->set($cachekey, new cacheable_object_array($repositories));
1147          return $repositories;
1148      }
1149  
1150      /**
1151       * Get single repository instance for administrative actions
1152       *
1153       * Do not use this function to access repository contents, because it
1154       * does not set the current context
1155       *
1156       * @see repository::get_repository_by_id()
1157       *
1158       * @static
1159       * @param integer $id repository instance id
1160       * @return repository
1161       */
1162      public static function get_instance($id) {
1163          return self::get_repository_by_id($id, context_system::instance());
1164      }
1165  
1166      /**
1167       * Call a static function. Any additional arguments than plugin and function will be passed through.
1168       *
1169       * @static
1170       * @param string $plugin repository plugin name
1171       * @param string $function function name
1172       * @return mixed
1173       */
1174      public static function static_function($plugin, $function) {
1175          global $CFG;
1176  
1177          //check that the plugin exists
1178          $typedirectory = $CFG->dirroot . '/repository/'. $plugin . '/lib.php';
1179          if (!file_exists($typedirectory)) {
1180              //throw new repository_exception('invalidplugin', 'repository');
1181              return false;
1182          }
1183  
1184          $args = func_get_args();
1185          if (count($args) <= 2) {
1186              $args = array();
1187          } else {
1188              array_shift($args);
1189              array_shift($args);
1190          }
1191  
1192          require_once($typedirectory);
1193          return call_user_func_array(array('repository_' . $plugin, $function), $args);
1194      }
1195  
1196      /**
1197       * Scan file, throws exception in case of infected file.
1198       *
1199       * Please note that the scanning engine must be able to access the file,
1200       * permissions of the file are not modified here!
1201       *
1202       * @static
1203       * @deprecated since Moodle 3.0
1204       * @param string $thefile
1205       * @param string $filename name of the file
1206       * @param bool $deleteinfected
1207       */
1208      public static function antivir_scan_file($thefile, $filename, $deleteinfected) {
1209          debugging('Please upgrade your code to use \core\antivirus\manager::scan_file instead', DEBUG_DEVELOPER);
1210          \core\antivirus\manager::scan_file($thefile, $filename, $deleteinfected);
1211      }
1212  
1213      /**
1214       * Repository method to serve the referenced file
1215       *
1216       * @see send_stored_file
1217       *
1218       * @param stored_file $storedfile the file that contains the reference
1219       * @param int $lifetime Number of seconds before the file should expire from caches (null means $CFG->filelifetime)
1220       * @param int $filter 0 (default)=no filtering, 1=all files, 2=html files only
1221       * @param bool $forcedownload If true (default false), forces download of file rather than view in browser/plugin
1222       * @param array $options additional options affecting the file serving
1223       */
1224      public function send_file($storedfile, $lifetime=null , $filter=0, $forcedownload=false, array $options = null) {
1225          if ($this->has_moodle_files()) {
1226              $fs = get_file_storage();
1227              $params = file_storage::unpack_reference($storedfile->get_reference(), true);
1228              $srcfile = null;
1229              if (is_array($params)) {
1230                  $srcfile = $fs->get_file($params['contextid'], $params['component'], $params['filearea'],
1231                          $params['itemid'], $params['filepath'], $params['filename']);
1232              }
1233              if (empty($options)) {
1234                  $options = array();
1235              }
1236              if (!isset($options['filename'])) {
1237                  $options['filename'] = $storedfile->get_filename();
1238              }
1239              if (!$srcfile) {
1240                  send_file_not_found();
1241              } else {
1242                  send_stored_file($srcfile, $lifetime, $filter, $forcedownload, $options);
1243              }
1244          } else {
1245              throw new coding_exception("Repository plugin must implement send_file() method.");
1246          }
1247      }
1248  
1249      /**
1250       * Return human readable reference information
1251       *
1252       * @param string $reference value of DB field files_reference.reference
1253       * @param int $filestatus status of the file, 0 - ok, 666 - source missing
1254       * @return string
1255       */
1256      public function get_reference_details($reference, $filestatus = 0) {
1257          if ($this->has_moodle_files()) {
1258              $fileinfo = null;
1259              $params = file_storage::unpack_reference($reference, true);
1260              if (is_array($params)) {
1261                  $context = context::instance_by_id($params['contextid'], IGNORE_MISSING);
1262                  if ($context) {
1263                      $browser = get_file_browser();
1264                      $fileinfo = $browser->get_file_info($context, $params['component'], $params['filearea'], $params['itemid'], $params['filepath'], $params['filename']);
1265                  }
1266              }
1267              if (empty($fileinfo)) {
1268                  if ($filestatus == 666) {
1269                      if (is_siteadmin() || ($context && has_capability('moodle/course:managefiles', $context))) {
1270                          return get_string('lostsource', 'repository',
1271                                  $params['contextid']. '/'. $params['component']. '/'. $params['filearea']. '/'. $params['itemid']. $params['filepath']. $params['filename']);
1272                      } else {
1273                          return get_string('lostsource', 'repository', '');
1274                      }
1275                  }
1276                  return get_string('undisclosedsource', 'repository');
1277              } else {
1278                  return $fileinfo->get_readable_fullname();
1279              }
1280          }
1281          return '';
1282      }
1283  
1284      /**
1285       * Cache file from external repository by reference
1286       * {@link repository::get_file_reference()}
1287       * {@link repository::get_file()}
1288       * Invoked at MOODLE/repository/repository_ajax.php
1289       *
1290       * @param string $reference this reference is generated by
1291       *                          repository::get_file_reference()
1292       * @param stored_file $storedfile created file reference
1293       */
1294      public function cache_file_by_reference($reference, $storedfile) {
1295      }
1296  
1297      /**
1298       * reference_file_selected
1299       *
1300       * This function is called when a controlled link file is selected in a file picker and the form is
1301       * saved. The expected behaviour for repositories supporting controlled links is to
1302       * - copy the file to the moodle system account
1303       * - put it in a folder that reflects the context it is being used
1304       * - make sure the sharing permissions are correct (read-only with the link)
1305       * - return a new reference string pointing to the newly copied file.
1306       *
1307       * @param string $reference this reference is generated by
1308       *                          repository::get_file_reference()
1309       * @param context $context the target context for this new file.
1310       * @param string $component the target component for this new file.
1311       * @param string $filearea the target filearea for this new file.
1312       * @param string $itemid the target itemid for this new file.
1313       * @return string updated reference (final one before it's saved to db).
1314       */
1315      public function reference_file_selected($reference, $context, $component, $filearea, $itemid) {
1316          return $reference;
1317      }
1318  
1319      /**
1320       * Return the source information
1321       *
1322       * The result of the function is stored in files.source field. It may be analysed
1323       * when the source file is lost or repository may use it to display human-readable
1324       * location of reference original.
1325       *
1326       * This method is called when file is picked for the first time only. When file
1327       * (either copy or a reference) is already in moodle and it is being picked
1328       * again to another file area (also as a copy or as a reference), the value of
1329       * files.source is copied.
1330       *
1331       * @param string $source source of the file, returned by repository as 'source' and received back from user (not cleaned)
1332       * @return string|null
1333       */
1334      public function get_file_source_info($source) {
1335          if ($this->has_moodle_files()) {
1336              $reference = $this->get_file_reference($source);
1337              return $this->get_reference_details($reference, 0);
1338          }
1339          return $source;
1340      }
1341  
1342      /**
1343       * Move file from download folder to file pool using FILE API
1344       *
1345       * @todo MDL-28637
1346       * @static
1347       * @param string $thefile file path in download folder
1348       * @param stdClass $record
1349       * @return array containing the following keys:
1350       *           icon
1351       *           file
1352       *           id
1353       *           url
1354       */
1355      public static function move_to_filepool($thefile, $record) {
1356          global $DB, $CFG, $USER, $OUTPUT;
1357  
1358          // scan for viruses if possible, throws exception if problem found
1359          // TODO: MDL-28637 this repository_no_delete is a bloody hack!
1360          \core\antivirus\manager::scan_file($thefile, $record->filename, empty($CFG->repository_no_delete));
1361  
1362          $fs = get_file_storage();
1363          // If file name being used.
1364          if (repository::draftfile_exists($record->itemid, $record->filepath, $record->filename)) {
1365              $draftitemid = $record->itemid;
1366              $new_filename = repository::get_unused_filename($draftitemid, $record->filepath, $record->filename);
1367              $old_filename = $record->filename;
1368              // Create a tmp file.
1369              $record->filename = $new_filename;
1370              $newfile = $fs->create_file_from_pathname($record, $thefile);
1371              $event = array();
1372              $event['event'] = 'fileexists';
1373              $event['newfile'] = new stdClass;
1374              $event['newfile']->filepath = $record->filepath;
1375              $event['newfile']->filename = $new_filename;
1376              $event['newfile']->url = moodle_url::make_draftfile_url($draftitemid, $record->filepath, $new_filename)->out();
1377  
1378              $event['existingfile'] = new stdClass;
1379              $event['existingfile']->filepath = $record->filepath;
1380              $event['existingfile']->filename = $old_filename;
1381              $event['existingfile']->url      = moodle_url::make_draftfile_url($draftitemid, $record->filepath, $old_filename)->out();
1382              return $event;
1383          }
1384          if ($file = $fs->create_file_from_pathname($record, $thefile)) {
1385              if (empty($CFG->repository_no_delete)) {
1386                  $delete = unlink($thefile);
1387                  unset($CFG->repository_no_delete);
1388              }
1389              return array(
1390                  'url'=>moodle_url::make_draftfile_url($file->get_itemid(), $file->get_filepath(), $file->get_filename())->out(),
1391                  'id'=>$file->get_itemid(),
1392                  'file'=>$file->get_filename(),
1393                  'icon' => $OUTPUT->image_url(file_extension_icon($thefile, 32))->out(),
1394              );
1395          } else {
1396              return null;
1397          }
1398      }
1399  
1400      /**
1401       * Builds a tree of files This function is then called recursively.
1402       *
1403       * @static
1404       * @todo take $search into account, and respect a threshold for dynamic loading
1405       * @param file_info $fileinfo an object returned by file_browser::get_file_info()
1406       * @param string $search searched string
1407       * @param bool $dynamicmode no recursive call is done when in dynamic mode
1408       * @param array $list the array containing the files under the passed $fileinfo
1409       * @return int the number of files found
1410       */
1411      public static function build_tree($fileinfo, $search, $dynamicmode, &$list) {
1412          global $CFG, $OUTPUT;
1413  
1414          $filecount = 0;
1415          $children = $fileinfo->get_children();
1416  
1417          foreach ($children as $child) {
1418              $filename = $child->get_visible_name();
1419              $filesize = $child->get_filesize();
1420              $filesize = $filesize ? display_size($filesize) : '';
1421              $filedate = $child->get_timemodified();
1422              $filedate = $filedate ? userdate($filedate) : '';
1423              $filetype = $child->get_mimetype();
1424  
1425              if ($child->is_directory()) {
1426                  $path = array();
1427                  $level = $child->get_parent();
1428                  while ($level) {
1429                      $params = $level->get_params();
1430                      $path[] = array($params['filepath'], $level->get_visible_name());
1431                      $level = $level->get_parent();
1432                  }
1433  
1434                  $tmp = array(
1435                      'title' => $child->get_visible_name(),
1436                      'size' => 0,
1437                      'date' => $filedate,
1438                      'path' => array_reverse($path),
1439                      'thumbnail' => $OUTPUT->image_url(file_folder_icon(90))->out(false)
1440                  );
1441  
1442                  //if ($dynamicmode && $child->is_writable()) {
1443                  //    $tmp['children'] = array();
1444                  //} else {
1445                      // if folder name matches search, we send back all files contained.
1446                  $_search = $search;
1447                  if ($search && stristr($tmp['title'], $search) !== false) {
1448                      $_search = false;
1449                  }
1450                  $tmp['children'] = array();
1451                  $_filecount = repository::build_tree($child, $_search, $dynamicmode, $tmp['children']);
1452                  if ($search && $_filecount) {
1453                      $tmp['expanded'] = 1;
1454                  }
1455  
1456                  //}
1457  
1458                  if (!$search || $_filecount || (stristr($tmp['title'], $search) !== false)) {
1459                      $filecount += $_filecount;
1460                      $list[] = $tmp;
1461                  }
1462  
1463              } else { // not a directory
1464                  // skip the file, if we're in search mode and it's not a match
1465                  if ($search && (stristr($filename, $search) === false)) {
1466                      continue;
1467                  }
1468                  $params = $child->get_params();
1469                  $source = serialize(array($params['contextid'], $params['component'], $params['filearea'], $params['itemid'], $params['filepath'], $params['filename']));
1470                  $list[] = array(
1471                      'title' => $filename,
1472                      'size' => $filesize,
1473                      'date' => $filedate,
1474                      //'source' => $child->get_url(),
1475                      'source' => base64_encode($source),
1476                      'icon'=>$OUTPUT->image_url(file_file_icon($child, 24))->out(false),
1477                      'thumbnail'=>$OUTPUT->image_url(file_file_icon($child, 90))->out(false),
1478                  );
1479                  $filecount++;
1480              }
1481          }
1482  
1483          return $filecount;
1484      }
1485  
1486      /**
1487       * Display a repository instance list (with edit/delete/create links)
1488       *
1489       * @static
1490       * @param stdClass $context the context for which we display the instance
1491       * @param string $typename if set, we display only one type of instance
1492       */
1493      public static function display_instances_list($context, $typename = null) {
1494          global $CFG, $USER, $OUTPUT;
1495  
1496          $output = $OUTPUT->box_start('generalbox');
1497          //if the context is SYSTEM, so we call it from administration page
1498          $admin = ($context->id == SYSCONTEXTID) ? true : false;
1499          if ($admin) {
1500              $baseurl = new moodle_url('/admin/repositoryinstance.php');
1501              $output .= $OUTPUT->heading(get_string('siteinstances', 'repository'));
1502          } else {
1503              $baseurl = new moodle_url('/repository/manage_instances.php', ['contextid' => $context->id]);
1504          }
1505  
1506          $namestr = get_string('name');
1507          $pluginstr = get_string('plugin', 'repository');
1508          $settingsstr = get_string('settings');
1509          $deletestr = get_string('delete');
1510          // Retrieve list of instances. In administration context we want to display all
1511          // instances of a type, even if this type is not visible. In course/user context we
1512          // want to display only visible instances, but for every type types. The repository::get_instances()
1513          // third parameter displays only visible type.
1514          $params = array();
1515          $params['context'] = array($context);
1516          $params['currentcontext'] = $context;
1517          $params['return_types'] = 0;
1518          $params['onlyvisible'] = !$admin;
1519          $params['type']        = $typename;
1520          $instances = repository::get_instances($params);
1521          $instancesnumber = count($instances);
1522          $alreadyplugins = array();
1523  
1524          $table = new html_table();
1525          $table->head = array($namestr, $pluginstr, $settingsstr, $deletestr);
1526          $table->align = array('left', 'left', 'center','center');
1527          $table->data = array();
1528  
1529          $updowncount = 1;
1530  
1531          foreach ($instances as $i) {
1532              $settings = '';
1533              $delete = '';
1534  
1535              $type = repository::get_type_by_id($i->options['typeid']);
1536  
1537              if ($type->get_contextvisibility($context)) {
1538                  if (!$i->readonly) {
1539  
1540                      $settingurl = new moodle_url($baseurl);
1541                      $settingurl->param('type', $i->options['type']);
1542                      $settingurl->param('edit', $i->id);
1543                      $settings .= html_writer::link($settingurl, $settingsstr);
1544  
1545                      $deleteurl = new moodle_url($baseurl);
1546                      $deleteurl->param('delete', $i->id);
1547                      $deleteurl->param('type', $i->options['type']);
1548                      $delete .= html_writer::link($deleteurl, $deletestr);
1549                  }
1550              }
1551  
1552              $type = repository::get_type_by_id($i->options['typeid']);
1553              $table->data[] = array(format_string($i->name), $type->get_readablename(), $settings, $delete);
1554  
1555              //display a grey row if the type is defined as not visible
1556              if (isset($type) && !$type->get_visible()) {
1557                  $table->rowclasses[] = 'dimmed_text';
1558              } else {
1559                  $table->rowclasses[] = '';
1560              }
1561  
1562              if (!in_array($i->name, $alreadyplugins)) {
1563                  $alreadyplugins[] = $i->name;
1564              }
1565          }
1566          $output .= html_writer::table($table);
1567          $instancehtml = '<div>';
1568          $addable = 0;
1569  
1570          //if no type is set, we can create all type of instance
1571          if (!$typename) {
1572              $instancehtml .= '<h3>';
1573              $instancehtml .= get_string('createrepository', 'repository');
1574              $instancehtml .= '</h3><ul>';
1575              $types = repository::get_editable_types($context);
1576              foreach ($types as $type) {
1577                  if (!empty($type) && $type->get_visible()) {
1578                      // If the user does not have the permission to view the repository, it won't be displayed in
1579                      // the list of instances. Hiding the link to create new instances will prevent the
1580                      // user from creating them without being able to find them afterwards, which looks like a bug.
1581                      if (!has_capability('repository/'.$type->get_typename().':view', $context)) {
1582                          continue;
1583                      }
1584                      $instanceoptionnames = repository::static_function($type->get_typename(), 'get_instance_option_names');
1585                      if (!empty($instanceoptionnames)) {
1586                          $baseurl->param('new', $type->get_typename());
1587                          $instancehtml .= '<li><a href="'.$baseurl->out().'">'.get_string('createxxinstance', 'repository', get_string('pluginname', 'repository_'.$type->get_typename())).  '</a></li>';
1588                          $baseurl->remove_params('new');
1589                          $addable++;
1590                      }
1591                  }
1592              }
1593              $instancehtml .= '</ul>';
1594  
1595          } else {
1596              $instanceoptionnames = repository::static_function($typename, 'get_instance_option_names');
1597              if (!empty($instanceoptionnames)) {   //create a unique type of instance
1598                  $addable = 1;
1599                  $baseurl->param('new', $typename);
1600                  $output .= $OUTPUT->single_button($baseurl, get_string('createinstance', 'repository'), 'get');
1601                  $baseurl->remove_params('new');
1602              }
1603          }
1604  
1605          if ($addable) {
1606              $instancehtml .= '</div>';
1607              $output .= $instancehtml;
1608          }
1609  
1610          $output .= $OUTPUT->box_end();
1611  
1612          //print the list + creation links
1613          print($output);
1614      }
1615  
1616      /**
1617       * Prepare file reference information
1618       *
1619       * @param string $source source of the file, returned by repository as 'source' and received back from user (not cleaned)
1620       * @return string file reference, ready to be stored
1621       */
1622      public function get_file_reference($source) {
1623          if ($source && $this->has_moodle_files()) {
1624              $params = @json_decode(base64_decode($source), true);
1625              if (!is_array($params) || empty($params['contextid'])) {
1626                  throw new repository_exception('invalidparams', 'repository');
1627              }
1628              $params = array(
1629                  'component' => empty($params['component']) ? ''   : clean_param($params['component'], PARAM_COMPONENT),
1630                  'filearea'  => empty($params['filearea'])  ? ''   : clean_param($params['filearea'], PARAM_AREA),
1631                  'itemid'    => empty($params['itemid'])    ? 0    : clean_param($params['itemid'], PARAM_INT),
1632                  'filename'  => empty($params['filename'])  ? null : clean_param($params['filename'], PARAM_FILE),
1633                  'filepath'  => empty($params['filepath'])  ? null : clean_param($params['filepath'], PARAM_PATH),
1634                  'contextid' => clean_param($params['contextid'], PARAM_INT)
1635              );
1636              // Check if context exists.
1637              if (!context::instance_by_id($params['contextid'], IGNORE_MISSING)) {
1638                  throw new repository_exception('invalidparams', 'repository');
1639              }
1640              return file_storage::pack_reference($params);
1641          }
1642          return $source;
1643      }
1644  
1645      /**
1646       * Get a unique file path in which to save the file.
1647       *
1648       * The filename returned will be removed at the end of the request and
1649       * should not be relied upon to exist in subsequent requests.
1650       *
1651       * @param string $filename file name
1652       * @return file path
1653       */
1654      public function prepare_file($filename) {
1655          if (empty($filename)) {
1656              $filename = 'file';
1657          }
1658          return sprintf('%s/%s', make_request_directory(), $filename);
1659      }
1660  
1661      /**
1662       * Does this repository used to browse moodle files?
1663       *
1664       * @return bool
1665       */
1666      public function has_moodle_files() {
1667          return false;
1668      }
1669  
1670      /**
1671       * Return file URL, for most plugins, the parameter is the original
1672       * url, but some plugins use a file id, so we need this function to
1673       * convert file id to original url.
1674       *
1675       * @param string $url the url of file
1676       * @return string
1677       */
1678      public function get_link($url) {
1679          return $url;
1680      }
1681  
1682      /**
1683       * Downloads a file from external repository and saves it in temp dir
1684       *
1685       * Function get_file() must be implemented by repositories that support returntypes
1686       * FILE_INTERNAL or FILE_REFERENCE. It is invoked to pick up the file and copy it
1687       * to moodle. This function is not called for moodle repositories, the function
1688       * {@link repository::copy_to_area()} is used instead.
1689       *
1690       * This function can be overridden by subclass if the files.reference field contains
1691       * not just URL or if request should be done differently.
1692       *
1693       * @see curl
1694       * @throws file_exception when error occured
1695       *
1696       * @param string $url the content of files.reference field, in this implementaion
1697       * it is asssumed that it contains the string with URL of the file
1698       * @param string $filename filename (without path) to save the downloaded file in the
1699       * temporary directory, if omitted or file already exists the new filename will be generated
1700       * @return array with elements:
1701       *   path: internal location of the file
1702       *   url: URL to the source (from parameters)
1703       */
1704      public function get_file($url, $filename = '') {
1705          global $CFG;
1706  
1707          $path = $this->prepare_file($filename);
1708          $c = new curl;
1709  
1710          $result = $c->download_one($url, null, array('filepath' => $path, 'timeout' => $CFG->repositorygetfiletimeout));
1711          if ($result !== true) {
1712              throw new moodle_exception('errorwhiledownload', 'repository', '', $result);
1713          }
1714          return array('path'=>$path, 'url'=>$url);
1715      }
1716  
1717      /**
1718       * Downloads the file from external repository and saves it in moodle filepool.
1719       * This function is different from {@link repository::sync_reference()} because it has
1720       * bigger request timeout and always downloads the content.
1721       *
1722       * This function is invoked when we try to unlink the file from the source and convert
1723       * a reference into a true copy.
1724       *
1725       * @throws exception when file could not be imported
1726       *
1727       * @param stored_file $file
1728       * @param int $maxbytes throw an exception if file size is bigger than $maxbytes (0 means no limit)
1729       */
1730      public function import_external_file_contents(stored_file $file, $maxbytes = 0) {
1731          if (!$file->is_external_file()) {
1732              // nothing to import if the file is not a reference
1733              return;
1734          } else if ($file->get_repository_id() != $this->id) {
1735              // error
1736              debugging('Repository instance id does not match');
1737              return;
1738          } else if ($this->has_moodle_files()) {
1739              // files that are references to local files are already in moodle filepool
1740              // just validate the size
1741              if ($maxbytes > 0 && $file->get_filesize() > $maxbytes) {
1742                  $maxbytesdisplay = display_size($maxbytes, 0);
1743                  throw new file_exception('maxbytesfile', (object) array('file' => $file->get_filename(),
1744                                                                          'size' => $maxbytesdisplay));
1745              }
1746              return;
1747          } else {
1748              if ($maxbytes > 0 && $file->get_filesize() > $maxbytes) {
1749                  // note that stored_file::get_filesize() also calls synchronisation
1750                  $maxbytesdisplay = display_size($maxbytes, 0);
1751                  throw new file_exception('maxbytesfile', (object) array('file' => $file->get_filename(),
1752                                                                          'size' => $maxbytesdisplay));
1753              }
1754              $fs = get_file_storage();
1755  
1756              // If a file has been downloaded, the file record should report both a positive file
1757              // size, and a contenthash which does not related to empty content.
1758              // If thereis no file size, or the contenthash is for an empty file, then the file has
1759              // yet to be successfully downloaded.
1760              $contentexists = $file->get_filesize() && !$file->compare_to_string('');
1761  
1762              if (!$file->get_status() && $contentexists) {
1763                  // we already have the content in moodle filepool and it was synchronised recently.
1764                  // Repositories may overwrite it if they want to force synchronisation anyway!
1765                  return;
1766              } else {
1767                  // attempt to get a file
1768                  try {
1769                      $fileinfo = $this->get_file($file->get_reference());
1770                      if (isset($fileinfo['path'])) {
1771                          $file->set_synchronised_content_from_file($fileinfo['path']);
1772                      } else {
1773                          throw new moodle_exception('errorwhiledownload', 'repository', '', '');
1774                      }
1775                  } catch (Exception $e) {
1776                      if ($contentexists) {
1777                          // better something than nothing. We have a copy of file. It's sync time
1778                          // has expired but it is still very likely that it is the last version
1779                      } else {
1780                          throw($e);
1781                      }
1782                  }
1783              }
1784          }
1785      }
1786  
1787      /**
1788       * Return size of a file in bytes.
1789       *
1790       * @param string $source encoded and serialized data of file
1791       * @return int file size in bytes
1792       */
1793      public function get_file_size($source) {
1794          // TODO MDL-33297 remove this function completely?
1795          $browser    = get_file_browser();
1796          $params     = unserialize(base64_decode($source));
1797          $contextid  = clean_param($params['contextid'], PARAM_INT);
1798          $fileitemid = clean_param($params['itemid'], PARAM_INT);
1799          $filename   = clean_param($params['filename'], PARAM_FILE);
1800          $filepath   = clean_param($params['filepath'], PARAM_PATH);
1801          $filearea   = clean_param($params['filearea'], PARAM_AREA);
1802          $component  = clean_param($params['component'], PARAM_COMPONENT);
1803          $context    = context::instance_by_id($contextid);
1804          $file_info  = $browser->get_file_info($context, $component, $filearea, $fileitemid, $filepath, $filename);
1805          if (!empty($file_info)) {
1806              $filesize = $file_info->get_filesize();
1807          } else {
1808              $filesize = null;
1809          }
1810          return $filesize;
1811      }
1812  
1813      /**
1814       * Return is the instance is visible
1815       * (is the type visible ? is the context enable ?)
1816       *
1817       * @return bool
1818       */
1819      public function is_visible() {
1820          $type = repository::get_type_by_id($this->options['typeid']);
1821          $instanceoptions = repository::static_function($type->get_typename(), 'get_instance_option_names');
1822  
1823          if ($type->get_visible()) {
1824              //if the instance is unique so it's visible, otherwise check if the instance has a enabled context
1825              if (empty($instanceoptions) || $type->get_contextvisibility(context::instance_by_id($this->instance->contextid))) {
1826                  return true;
1827              }
1828          }
1829  
1830          return false;
1831      }
1832  
1833      /**
1834       * Can the instance be edited by the current user?
1835       *
1836       * The property $readonly must not be used within this method because
1837       * it only controls if the options from self::get_instance_option_names()
1838       * can be edited.
1839       *
1840       * @return bool true if the user can edit the instance.
1841       * @since Moodle 2.5
1842       */
1843      public final function can_be_edited_by_user() {
1844          global $USER;
1845  
1846          // We need to be able to explore the repository.
1847          try {
1848              $this->check_capability();
1849          } catch (repository_exception $e) {
1850              return false;
1851          }
1852  
1853          $repocontext = context::instance_by_id($this->instance->contextid);
1854          if ($repocontext->contextlevel == CONTEXT_USER && $repocontext->instanceid != $USER->id) {
1855              // If the context of this instance is a user context, we need to be this user.
1856              return false;
1857          } else if ($repocontext->contextlevel == CONTEXT_MODULE && !has_capability('moodle/course:update', $repocontext)) {
1858              // We need to have permissions on the course to edit the instance.
1859              return false;
1860          } else if ($repocontext->contextlevel == CONTEXT_SYSTEM && !has_capability('moodle/site:config', $repocontext)) {
1861              // Do not meet the requirements for the context system.
1862              return false;
1863          }
1864  
1865          return true;
1866      }
1867  
1868      /**
1869       * Return the name of this instance, can be overridden.
1870       *
1871       * @return string
1872       */
1873      public function get_name() {
1874          if ($name = $this->instance->name) {
1875              return $name;
1876          } else {
1877              return get_string('pluginname', 'repository_' . $this->get_typename());
1878          }
1879      }
1880  
1881      /**
1882       * Is this repository accessing private data?
1883       *
1884       * This function should return true for the repositories which access external private
1885       * data from a user. This is the case for repositories such as Dropbox, Google Docs or Box.net
1886       * which authenticate the user and then store the auth token.
1887       *
1888       * Of course, many repositories store 'private data', but we only want to set
1889       * contains_private_data() to repositories which are external to Moodle and shouldn't be accessed
1890       * to by the users having the capability to 'login as' someone else. For instance, the repository
1891       * 'Private files' is not considered as private because it's part of Moodle.
1892       *
1893       * You should not set contains_private_data() to true on repositories which allow different types
1894       * of instances as the levels other than 'user' are, by definition, not private. Also
1895       * the user instances will be protected when they need to.
1896       *
1897       * @return boolean True when the repository accesses private external data.
1898       * @since  Moodle 2.5
1899       */
1900      public function contains_private_data() {
1901          return true;
1902      }
1903  
1904      /**
1905       * What kind of files will be in this repository?
1906       *
1907       * @return array return '*' means this repository support any files, otherwise
1908       *               return mimetypes of files, it can be an array
1909       */
1910      public function supported_filetypes() {
1911          // return array('text/plain', 'image/gif');
1912          return '*';
1913      }
1914  
1915      /**
1916       * Tells how the file can be picked from this repository
1917       *
1918       * Maximum value is FILE_INTERNAL | FILE_EXTERNAL | FILE_REFERENCE
1919       *
1920       * @return int
1921       */
1922      public function supported_returntypes() {
1923          return (FILE_INTERNAL | FILE_EXTERNAL);
1924      }
1925  
1926      /**
1927       * Tells how the file can be picked from this repository
1928       *
1929       * Maximum value is FILE_INTERNAL | FILE_EXTERNAL | FILE_REFERENCE
1930       *
1931       * @return int
1932       */
1933      public function default_returntype() {
1934          return FILE_INTERNAL;
1935      }
1936  
1937      /**
1938       * Provide repository instance information for Ajax
1939       *
1940       * @return stdClass
1941       */
1942      final public function get_meta() {
1943          global $CFG, $OUTPUT;
1944          $meta = new stdClass();
1945          $meta->id   = $this->id;
1946          $meta->name = format_string($this->get_name());
1947          $meta->type = $this->get_typename();
1948          $meta->icon = $OUTPUT->image_url('icon', 'repository_'.$meta->type)->out(false);
1949          $meta->supported_types = file_get_typegroup('extension', $this->supported_filetypes());
1950          $meta->return_types = $this->supported_returntypes();
1951          $meta->defaultreturntype = $this->default_returntype();
1952          $meta->sortorder = $this->options['sortorder'];
1953          return $meta;
1954      }
1955  
1956      /**
1957       * Create an instance for this plug-in
1958       *
1959       * @static
1960       * @param string $type the type of the repository
1961       * @param int $userid the user id
1962       * @param stdClass $context the context
1963       * @param array $params the options for this instance
1964       * @param int $readonly whether to create it readonly or not (defaults to not)
1965       * @return mixed
1966       */
1967      public static function create($type, $userid, $context, $params, $readonly=0) {
1968          global $CFG, $DB;
1969          $params = (array)$params;
1970          require_once($CFG->dirroot . '/repository/'. $type . '/lib.php');
1971          $classname = 'repository_' . $type;
1972          if ($repo = $DB->get_record('repository', array('type'=>$type))) {
1973              $record = new stdClass();
1974              $record->name = $params['name'];
1975              $record->typeid = $repo->id;
1976              $record->timecreated  = time();
1977              $record->timemodified = time();
1978              $record->contextid = $context->id;
1979              $record->readonly = $readonly;
1980              $record->userid    = $userid;
1981              $id = $DB->insert_record('repository_instances', $record);
1982              cache::make('core', 'repositories')->purge();
1983              $options = array();
1984              $configs = call_user_func($classname . '::get_instance_option_names');
1985              if (!empty($configs)) {
1986                  foreach ($configs as $config) {
1987                      if (isset($params[$config])) {
1988                          $options[$config] = $params[$config];
1989                      } else {
1990                          $options[$config] = null;
1991                      }
1992                  }
1993              }
1994  
1995              if (!empty($id)) {
1996                  unset($options['name']);
1997                  $instance = repository::get_instance($id);
1998                  $instance->set_option($options);
1999                  return $id;
2000              } else {
2001                  return null;
2002              }
2003          } else {
2004              return null;
2005          }
2006      }
2007  
2008      /**
2009       * delete a repository instance
2010       *
2011       * @param bool $downloadcontents
2012       * @return bool
2013       */
2014      final public function delete($downloadcontents = false) {
2015          global $DB;
2016          if ($downloadcontents) {
2017              $this->convert_references_to_local();
2018          } else {
2019              $this->remove_files();
2020          }
2021          cache::make('core', 'repositories')->purge();
2022          try {
2023              $DB->delete_records('repository_instances', array('id'=>$this->id));
2024              $DB->delete_records('repository_instance_config', array('instanceid'=>$this->id));
2025          } catch (dml_exception $ex) {
2026              return false;
2027          }
2028          return true;
2029      }
2030  
2031      /**
2032       * Delete all the instances associated to a context.
2033       *
2034       * This method is intended to be a callback when deleting
2035       * a course or a user to delete all the instances associated
2036       * to their context. The usual way to delete a single instance
2037       * is to use {@link self::delete()}.
2038       *
2039       * @param int $contextid context ID.
2040       * @param boolean $downloadcontents true to convert references to hard copies.
2041       * @return void
2042       */
2043      final public static function delete_all_for_context($contextid, $downloadcontents = true) {
2044          global $DB;
2045          $repoids = $DB->get_fieldset_select('repository_instances', 'id', 'contextid = :contextid', array('contextid' => $contextid));
2046          if ($downloadcontents) {
2047              foreach ($repoids as $repoid) {
2048                  $repo = repository::get_repository_by_id($repoid, $contextid);
2049                  $repo->convert_references_to_local();
2050              }
2051          }
2052          cache::make('core', 'repositories')->purge();
2053          $DB->delete_records_list('repository_instances', 'id', $repoids);
2054          $DB->delete_records_list('repository_instance_config', 'instanceid', $repoids);
2055      }
2056  
2057      /**
2058       * Hide/Show a repository
2059       *
2060       * @param string $hide
2061       * @return bool
2062       */
2063      final public function hide($hide = 'toggle') {
2064          global $DB;
2065          if ($entry = $DB->get_record('repository', array('id'=>$this->id))) {
2066              if ($hide === 'toggle' ) {
2067                  if (!empty($entry->visible)) {
2068                      $entry->visible = 0;
2069                  } else {
2070                      $entry->visible = 1;
2071                  }
2072              } else {
2073                  if (!empty($hide)) {
2074                      $entry->visible = 0;
2075                  } else {
2076                      $entry->visible = 1;
2077                  }
2078              }
2079              return $DB->update_record('repository', $entry);
2080          }
2081          return false;
2082      }
2083  
2084      /**
2085       * Save settings for repository instance
2086       * $repo->set_option(array('api_key'=>'f2188bde132', 'name'=>'dongsheng'));
2087       *
2088       * @param array $options settings
2089       * @return bool
2090       */
2091      public function set_option($options = array()) {
2092          global $DB;
2093  
2094          if (!empty($options['name'])) {
2095              $r = new stdClass();
2096              $r->id   = $this->id;
2097              $r->name = $options['name'];
2098              $DB->update_record('repository_instances', $r);
2099              unset($options['name']);
2100          }
2101          foreach ($options as $name=>$value) {
2102              if ($id = $DB->get_field('repository_instance_config', 'id', array('name'=>$name, 'instanceid'=>$this->id))) {
2103                  $DB->set_field('repository_instance_config', 'value', $value, array('id'=>$id));
2104              } else {
2105                  $config = new stdClass();
2106                  $config->instanceid = $this->id;
2107                  $config->name   = $name;
2108                  $config->value  = $value;
2109                  $DB->insert_record('repository_instance_config', $config);
2110              }
2111          }
2112          cache::make('core', 'repositories')->purge();
2113          return true;
2114      }
2115  
2116      /**
2117       * Get settings for repository instance.
2118       *
2119       * @param string $config a specific option to get.
2120       * @return mixed returns an array of options. If $config is not empty, then it returns that option,
2121       *               or null if the option does not exist.
2122       */
2123      public function get_option($config = '') {
2124          global $DB;
2125          $cache = cache::make('core', 'repositories');
2126          if (($entries = $cache->get('ops:'. $this->id)) === false) {
2127              $entries = $DB->get_records('repository_instance_config', array('instanceid' => $this->id));
2128              $cache->set('ops:'. $this->id, $entries);
2129          }
2130  
2131          $ret = array();
2132          foreach($entries as $entry) {
2133              $ret[$entry->name] = $entry->value;
2134          }
2135  
2136          if (!empty($config)) {
2137              if (isset($ret[$config])) {
2138                  return $ret[$config];
2139              } else {
2140                  return null;
2141              }
2142          } else {
2143              return $ret;
2144          }
2145      }
2146  
2147      /**
2148       * Filter file listing to display specific types
2149       *
2150       * @param array $value
2151       * @return bool
2152       */
2153      public function filter($value) {
2154          $accepted_types = optional_param_array('accepted_types', '', PARAM_RAW);
2155          if (isset($value['children'])) {
2156              return true; // always return directories
2157          } else {
2158              if ($accepted_types == '*' or empty($accepted_types)
2159                  or (is_array($accepted_types) and in_array('*', $accepted_types))) {
2160                  return true;
2161              } else {
2162                  foreach ($accepted_types as $ext) {
2163                      if (preg_match('#'.$ext.'$#i', $value['title'])) {
2164                          return true;
2165                      }
2166                  }
2167              }
2168          }
2169          return false;
2170      }
2171  
2172      /**
2173       * Given a path, and perhaps a search, get a list of files.
2174       *
2175       * See details on {@link https://moodledev.io/docs/apis/plugintypes/repository}
2176       *
2177       * @param string $path this parameter can a folder name, or a identification of folder
2178       * @param string $page the page number of file list
2179       * @return array the list of files, including meta infomation, containing the following keys
2180       *           manage, url to manage url
2181       *           client_id
2182       *           login, login form
2183       *           repo_id, active repository id
2184       *           login_btn_action, the login button action
2185       *           login_btn_label, the login button label
2186       *           total, number of results
2187       *           perpage, items per page
2188       *           page
2189       *           pages, total pages
2190       *           issearchresult, is it a search result?
2191       *           list, file list
2192       *           path, current path and parent path
2193       */
2194      public function get_listing($path = '', $page = '') {
2195      }
2196  
2197  
2198      /**
2199       * Prepare the breadcrumb.
2200       *
2201       * @param array $breadcrumb contains each element of the breadcrumb.
2202       * @return array of breadcrumb elements.
2203       * @since Moodle 2.3.3
2204       */
2205      protected static function prepare_breadcrumb($breadcrumb) {
2206          global $OUTPUT;
2207          $foldericon = $OUTPUT->image_url(file_folder_icon(24))->out(false);
2208          $len = count($breadcrumb);
2209          for ($i = 0; $i < $len; $i++) {
2210              if (is_array($breadcrumb[$i]) && !isset($breadcrumb[$i]['icon'])) {
2211                  $breadcrumb[$i]['icon'] = $foldericon;
2212              } else if (is_object($breadcrumb[$i]) && !isset($breadcrumb[$i]->icon)) {
2213                  $breadcrumb[$i]->icon = $foldericon;
2214              }
2215          }
2216          return $breadcrumb;
2217      }
2218  
2219      /**
2220       * Prepare the file/folder listing.
2221       *
2222       * @param array $list of files and folders.
2223       * @return array of files and folders.
2224       * @since Moodle 2.3.3
2225       */
2226      protected static function prepare_list($list) {
2227          global $OUTPUT;
2228          $foldericon = $OUTPUT->image_url(file_folder_icon(24))->out(false);
2229  
2230          // Reset the array keys because non-numeric keys will create an object when converted to JSON.
2231          $list = array_values($list);
2232  
2233          $len = count($list);
2234          for ($i = 0; $i < $len; $i++) {
2235              if (is_object($list[$i])) {
2236                  $file = (array)$list[$i];
2237                  $converttoobject = true;
2238              } else {
2239                  $file =& $list[$i];
2240                  $converttoobject = false;
2241              }
2242  
2243              if (isset($file['source'])) {
2244                  $file['sourcekey'] = sha1($file['source'] . self::get_secret_key() . sesskey());
2245              }
2246  
2247              if (isset($file['size'])) {
2248                  $file['size'] = (int)$file['size'];
2249                  $file['size_f'] = display_size($file['size']);
2250              }
2251              if (isset($file['license']) && get_string_manager()->string_exists($file['license'], 'license')) {
2252                  $file['license_f'] = get_string($file['license'], 'license');
2253              }
2254              if (isset($file['image_width']) && isset($file['image_height'])) {
2255                  $a = array('width' => $file['image_width'], 'height' => $file['image_height']);
2256                  $file['dimensions'] = get_string('imagesize', 'repository', (object)$a);
2257              }
2258              foreach (array('date', 'datemodified', 'datecreated') as $key) {
2259                  if (!isset($file[$key]) && isset($file['date'])) {
2260                      $file[$key] = $file['date'];
2261                  }
2262                  if (isset($file[$key])) {
2263                      // must be UNIX timestamp
2264                      $file[$key] = (int)$file[$key];
2265                      if (!$file[$key]) {
2266                          unset($file[$key]);
2267                      } else {
2268                          $file[$key.'_f'] = userdate($file[$key], get_string('strftimedatetime', 'langconfig'));
2269                          $file[$key.'_f_s'] = userdate($file[$key], get_string('strftimedatetimeshort', 'langconfig'));
2270                      }
2271                  }
2272              }
2273              $isfolder = (array_key_exists('children', $file) || (isset($file['type']) && $file['type'] == 'folder'));
2274              $filename = null;
2275              if (isset($file['title'])) {
2276                  $filename = $file['title'];
2277              }
2278              else if (isset($file['fullname'])) {
2279                  $filename = $file['fullname'];
2280              }
2281              if (!isset($file['mimetype']) && !$isfolder && $filename) {
2282                  $file['mimetype'] = get_mimetype_description(array('filename' => $filename));
2283              }
2284              if (!isset($file['icon'])) {
2285                  if ($isfolder) {
2286                      $file['icon'] = $foldericon;
2287                  } else if ($filename) {
2288                      $file['icon'] = $OUTPUT->image_url(file_extension_icon($filename, 24))->out(false);
2289                  }
2290              }
2291  
2292              // Recursively loop over children.
2293              if (isset($file['children'])) {
2294                  $file['children'] = self::prepare_list($file['children']);
2295              }
2296  
2297              // Convert the array back to an object.
2298              if ($converttoobject) {
2299                  $list[$i] = (object)$file;
2300              }
2301          }
2302          return $list;
2303      }
2304  
2305      /**
2306       * Prepares list of files before passing it to AJAX, makes sure data is in the correct
2307       * format and stores formatted values.
2308       *
2309       * @param array|stdClass $listing result of get_listing() or search() or file_get_drafarea_files()
2310       * @return stdClass
2311       */
2312      public static function prepare_listing($listing) {
2313          $wasobject = false;
2314          if (is_object($listing)) {
2315              $listing = (array) $listing;
2316              $wasobject = true;
2317          }
2318  
2319          // Prepare the breadcrumb, passed as 'path'.
2320          if (isset($listing['path']) && is_array($listing['path'])) {
2321              $listing['path'] = self::prepare_breadcrumb($listing['path']);
2322          }
2323  
2324          // Prepare the listing of objects.
2325          if (isset($listing['list']) && is_array($listing['list'])) {
2326              $listing['list'] = self::prepare_list($listing['list']);
2327          }
2328  
2329          // Convert back to an object.
2330          if ($wasobject) {
2331              $listing = (object) $listing;
2332          }
2333          return $listing;
2334      }
2335  
2336      /**
2337       * Search files in repository
2338       * When doing global search, $search_text will be used as
2339       * keyword.
2340       *
2341       * @param string $search_text search key word
2342       * @param int $page page
2343       * @return mixed see {@link repository::get_listing()}
2344       */
2345      public function search($search_text, $page = 0) {
2346          $list = array();
2347          $list['list'] = array();
2348          return false;
2349      }
2350  
2351      /**
2352       * Logout from repository instance
2353       * By default, this function will return a login form
2354       *
2355       * @return string
2356       */
2357      public function logout(){
2358          return $this->print_login();
2359      }
2360  
2361      /**
2362       * To check whether the user is logged in.
2363       *
2364       * @return bool
2365       */
2366      public function check_login(){
2367          return true;
2368      }
2369  
2370  
2371      /**
2372       * Show the login screen, if required
2373       *
2374       * @return string
2375       */
2376      public function print_login(){
2377          return $this->get_listing();
2378      }
2379  
2380      /**
2381       * Show the search screen, if required
2382       *
2383       * @return string
2384       */
2385      public function print_search() {
2386          global $PAGE;
2387          $renderer = $PAGE->get_renderer('core', 'files');
2388          return $renderer->repository_default_searchform();
2389      }
2390  
2391      /**
2392       * For oauth like external authentication, when external repository direct user back to moodle,
2393       * this function will be called to set up token and token_secret
2394       */
2395      public function callback() {
2396      }
2397  
2398      /**
2399       * is it possible to do glboal search?
2400       *
2401       * @return bool
2402       */
2403      public function global_search() {
2404          return false;
2405      }
2406  
2407      /**
2408       * Defines operations that happen occasionally on cron
2409       *
2410       * @return bool
2411       */
2412      public function cron() {
2413          return true;
2414      }
2415  
2416      /**
2417       * function which is run when the type is created (moodle administrator add the plugin)
2418       *
2419       * @return bool success or fail?
2420       */
2421      public static function plugin_init() {
2422          return true;
2423      }
2424  
2425      /**
2426       * Edit/Create Admin Settings Moodle form
2427       *
2428       * @param MoodleQuickForm $mform Moodle form (passed by reference)
2429       * @param string $classname repository class name
2430       */
2431      public static function type_config_form($mform, $classname = 'repository') {
2432          $instnaceoptions = call_user_func(array($classname, 'get_instance_option_names'), $mform, $classname);
2433          if (empty($instnaceoptions)) {
2434              // this plugin has only one instance
2435              // so we need to give it a name
2436              // it can be empty, then moodle will look for instance name from language string
2437              $mform->addElement('text', 'pluginname', get_string('pluginname', 'repository'), array('size' => '40'));
2438              $mform->addElement('static', 'pluginnamehelp', '', get_string('pluginnamehelp', 'repository'));
2439              $mform->setType('pluginname', PARAM_TEXT);
2440          }
2441      }
2442  
2443      /**
2444       * Validate Admin Settings Moodle form
2445       *
2446       * @static
2447       * @param moodleform $mform Moodle form (passed by reference)
2448       * @param array $data array of ("fieldname"=>value) of submitted data
2449       * @param array $errors array of ("fieldname"=>errormessage) of errors
2450       * @return array array of errors
2451       */
2452      public static function type_form_validation($mform, $data, $errors) {
2453          return $errors;
2454      }
2455  
2456  
2457      /**
2458       * Edit/Create Instance Settings Moodle form
2459       *
2460       * @param moodleform $mform Moodle form (passed by reference)
2461       */
2462      public static function instance_config_form($mform) {
2463      }
2464  
2465      /**
2466       * Return names of the general options.
2467       * By default: no general option name
2468       *
2469       * @return array
2470       */
2471      public static function get_type_option_names() {
2472          return array('pluginname');
2473      }
2474  
2475      /**
2476       * Return names of the instance options.
2477       * By default: no instance option name
2478       *
2479       * @return array
2480       */
2481      public static function get_instance_option_names() {
2482          return array();
2483      }
2484  
2485      /**
2486       * Validate repository plugin instance form
2487       *
2488       * @param moodleform $mform moodle form
2489       * @param array $data form data
2490       * @param array $errors errors
2491       * @return array errors
2492       */
2493      public static function instance_form_validation($mform, $data, $errors) {
2494          return $errors;
2495      }
2496  
2497      /**
2498       * Create a shorten filename
2499       *
2500       * @param string $str filename
2501       * @param int $maxlength max file name length
2502       * @return string short filename
2503       */
2504      public function get_short_filename($str, $maxlength) {
2505          if (core_text::strlen($str) >= $maxlength) {
2506              return trim(core_text::substr($str, 0, $maxlength)).'...';
2507          } else {
2508              return $str;
2509          }
2510      }
2511  
2512      /**
2513       * Overwrite an existing file
2514       *
2515       * @param int $itemid
2516       * @param string $filepath
2517       * @param string $filename
2518       * @param string $newfilepath
2519       * @param string $newfilename
2520       * @return bool
2521       */
2522      public static function overwrite_existing_draftfile($itemid, $filepath, $filename, $newfilepath, $newfilename) {
2523          global $USER;
2524          $fs = get_file_storage();
2525          $user_context = context_user::instance($USER->id);
2526          if ($file = $fs->get_file($user_context->id, 'user', 'draft', $itemid, $filepath, $filename)) {
2527              if ($tempfile = $fs->get_file($user_context->id, 'user', 'draft', $itemid, $newfilepath, $newfilename)) {
2528                  // Remember original file source field.
2529                  $source = @unserialize($file->get_source());
2530                  // Remember the original sortorder.
2531                  $sortorder = $file->get_sortorder();
2532                  if ($tempfile->is_external_file()) {
2533                      // New file is a reference. Check that existing file does not have any other files referencing to it
2534                      if (isset($source->original) && $fs->search_references_count($source->original)) {
2535                          return (object)array('error' => get_string('errordoublereference', 'repository'));
2536                      }
2537                  }
2538                  // delete existing file to release filename
2539                  $file->delete();
2540                  // create new file
2541                  $newfile = $fs->create_file_from_storedfile(array('filepath'=>$filepath, 'filename'=>$filename), $tempfile);
2542                  // Preserve original file location (stored in source field) for handling references
2543                  if (isset($source->original)) {
2544                      if (!($newfilesource = @unserialize($newfile->get_source()))) {
2545                          $newfilesource = new stdClass();
2546                      }
2547                      $newfilesource->original = $source->original;
2548                      $newfile->set_source(serialize($newfilesource));
2549                  }
2550                  $newfile->set_sortorder($sortorder);
2551                  // remove temp file
2552                  $tempfile->delete();
2553                  return true;
2554              }
2555          }
2556          return false;
2557      }
2558  
2559      /**
2560       * Updates a file in draft filearea.
2561       *
2562       * This function can only update fields filepath, filename, author, license.
2563       * If anything (except filepath) is updated, timemodified is set to current time.
2564       * If filename or filepath is updated the file unconnects from it's origin
2565       * and therefore all references to it will be converted to copies when
2566       * filearea is saved.
2567       *
2568       * @param int $draftid
2569       * @param string $filepath path to the directory containing the file, or full path in case of directory
2570       * @param string $filename name of the file, or '.' in case of directory
2571       * @param array $updatedata array of fields to change (only filename, filepath, license and/or author can be updated)
2572       * @throws moodle_exception if for any reason file can not be updated (file does not exist, target already exists, etc.)
2573       */
2574      public static function update_draftfile($draftid, $filepath, $filename, $updatedata) {
2575          global $USER;
2576          $fs = get_file_storage();
2577          $usercontext = context_user::instance($USER->id);
2578          // make sure filename and filepath are present in $updatedata
2579          $updatedata = $updatedata + array('filepath' => $filepath, 'filename' => $filename);
2580          $filemodified = false;
2581          if (!$file = $fs->get_file($usercontext->id, 'user', 'draft', $draftid, $filepath, $filename)) {
2582              if ($filename === '.') {
2583                  throw new moodle_exception('foldernotfound', 'repository');
2584              } else {
2585                  throw new moodle_exception('filenotfound', 'error');
2586              }
2587          }
2588          if (!$file->is_directory()) {
2589              // This is a file
2590              if ($updatedata['filepath'] !== $filepath || $updatedata['filename'] !== $filename) {
2591                  // Rename/move file: check that target file name does not exist.
2592                  if ($fs->file_exists($usercontext->id, 'user', 'draft', $draftid, $updatedata['filepath'], $updatedata['filename'])) {
2593                      throw new moodle_exception('fileexists', 'repository');
2594                  }
2595                  if (($filesource = @unserialize($file->get_source())) && isset($filesource->original)) {
2596                      unset($filesource->original);
2597                      $file->set_source(serialize($filesource));
2598                  }
2599                  $file->rename($updatedata['filepath'], $updatedata['filename']);
2600                  // timemodified is updated only when file is renamed and not updated when file is moved.
2601                  $filemodified = $filemodified || ($updatedata['filename'] !== $filename);
2602              }
2603              if (array_key_exists('license', $updatedata) && $updatedata['license'] !== $file->get_license()) {
2604                  // Update license and timemodified.
2605                  $file->set_license($updatedata['license']);
2606                  $filemodified = true;
2607              }
2608              if (array_key_exists('author', $updatedata) && $updatedata['author'] !== $file->get_author()) {
2609                  // Update author and timemodified.
2610                  $file->set_author($updatedata['author']);
2611                  $filemodified = true;
2612              }
2613              // Update timemodified:
2614              if ($filemodified) {
2615                  $file->set_timemodified(time());
2616              }
2617          } else {
2618              // This is a directory - only filepath can be updated for a directory (it was moved).
2619              if ($updatedata['filepath'] === $filepath) {
2620                  // nothing to update
2621                  return;
2622              }
2623              if ($fs->file_exists($usercontext->id, 'user', 'draft', $draftid, $updatedata['filepath'], '.')) {
2624                  // bad luck, we can not rename if something already exists there
2625                  throw new moodle_exception('folderexists', 'repository');
2626              }
2627              $xfilepath = preg_quote($filepath, '|');
2628              if (preg_match("|^$xfilepath|", $updatedata['filepath'])) {
2629                  // we can not move folder to it's own subfolder
2630                  throw new moodle_exception('folderrecurse', 'repository');
2631              }
2632  
2633              // If directory changed the name, update timemodified.
2634              $filemodified = (basename(rtrim($file->get_filepath(), '/')) !== basename(rtrim($updatedata['filepath'], '/')));
2635  
2636              // Now update directory and all children.
2637              $files = $fs->get_area_files($usercontext->id, 'user', 'draft', $draftid);
2638              foreach ($files as $f) {
2639                  if (preg_match("|^$xfilepath|", $f->get_filepath())) {
2640                      $path = preg_replace("|^$xfilepath|", $updatedata['filepath'], $f->get_filepath());
2641                      if (($filesource = @unserialize($f->get_source())) && isset($filesource->original)) {
2642                          // unset original so the references are not shown any more
2643                          unset($filesource->original);
2644                          $f->set_source(serialize($filesource));
2645                      }
2646                      $f->rename($path, $f->get_filename());
2647                      if ($filemodified && $f->get_filepath() === $updatedata['filepath'] && $f->get_filename() === $filename) {
2648                          $f->set_timemodified(time());
2649                      }
2650                  }
2651              }
2652          }
2653      }
2654  
2655      /**
2656       * Delete a temp file from draft area
2657       *
2658       * @param int $draftitemid
2659       * @param string $filepath
2660       * @param string $filename
2661       * @return bool
2662       */
2663      public static function delete_tempfile_from_draft($draftitemid, $filepath, $filename) {
2664          global $USER;
2665          $fs = get_file_storage();
2666          $user_context = context_user::instance($USER->id);
2667          if ($file = $fs->get_file($user_context->id, 'user', 'draft', $draftitemid, $filepath, $filename)) {
2668              $file->delete();
2669              return true;
2670          } else {
2671              return false;
2672          }
2673      }
2674  
2675      /**
2676       * Find all external files in this repo and import them
2677       */
2678      public function convert_references_to_local() {
2679          $fs = get_file_storage();
2680          $files = $fs->get_external_files($this->id);
2681          foreach ($files as $storedfile) {
2682              $fs->import_external_file($storedfile);
2683          }
2684      }
2685  
2686      /**
2687       * Find all external files linked to this repository and delete them.
2688       */
2689      public function remove_files() {
2690          $fs = get_file_storage();
2691          $files = $fs->get_external_files($this->id);
2692          foreach ($files as $storedfile) {
2693              $storedfile->delete();
2694          }
2695      }
2696  
2697      /**
2698       * Function repository::reset_caches() is deprecated, cache is handled by MUC now.
2699       * @deprecated since Moodle 2.6 MDL-42016 - please do not use this function any more.
2700       */
2701      public static function reset_caches() {
2702          throw new coding_exception('Function repository::reset_caches() can not be used any more, cache is handled by MUC now.');
2703      }
2704  
2705      /**
2706       * Function repository::sync_external_file() is deprecated. Use repository::sync_reference instead
2707       *
2708       * @deprecated since Moodle 2.6 MDL-42016 - please do not use this function any more.
2709       * @see repository::sync_reference()
2710       */
2711      public static function sync_external_file($file, $resetsynchistory = false) {
2712          throw new coding_exception('Function repository::sync_external_file() can not be used any more. ' .
2713              'Use repository::sync_reference instead.');
2714      }
2715  
2716      /**
2717       * Performs synchronisation of an external file if the previous one has expired.
2718       *
2719       * This function must be implemented for external repositories supporting
2720       * FILE_REFERENCE, it is called for existing aliases when their filesize,
2721       * contenthash or timemodified are requested. It is not called for internal
2722       * repositories (see {@link repository::has_moodle_files()}), references to
2723       * internal files are updated immediately when source is modified.
2724       *
2725       * Referenced files may optionally keep their content in Moodle filepool (for
2726       * thumbnail generation or to be able to serve cached copy). In this
2727       * case both contenthash and filesize need to be synchronized. Otherwise repositories
2728       * should use contenthash of empty file and correct filesize in bytes.
2729       *
2730       * Note that this function may be run for EACH file that needs to be synchronised at the
2731       * moment. If anything is being downloaded or requested from external sources there
2732       * should be a small timeout. The synchronisation is performed to update the size of
2733       * the file and/or to update image and re-generated image preview. There is nothing
2734       * fatal if syncronisation fails but it is fatal if syncronisation takes too long
2735       * and hangs the script generating a page.
2736       *
2737       * Note: If you wish to call $file->get_filesize(), $file->get_contenthash() or
2738       * $file->get_timemodified() make sure that recursion does not happen.
2739       *
2740       * Called from {@link stored_file::sync_external_file()}
2741       *
2742       * @uses stored_file::set_missingsource()
2743       * @uses stored_file::set_synchronized()
2744       * @param stored_file $file
2745       * @return bool false when file does not need synchronisation, true if it was synchronised
2746       */
2747      public function sync_reference(stored_file $file) {
2748          if ($file->get_repository_id() != $this->id) {
2749              // This should not really happen because the function can be called from stored_file only.
2750              return false;
2751          }
2752  
2753          if ($this->has_moodle_files()) {
2754              // References to local files need to be synchronised only once.
2755              // Later they will be synchronised automatically when the source is changed.
2756              if ($file->get_referencelastsync()) {
2757                  return false;
2758              }
2759              $fs = get_file_storage();
2760              $params = file_storage::unpack_reference($file->get_reference(), true);
2761              if (!is_array($params) || !($storedfile = $fs->get_file($params['contextid'],
2762                      $params['component'], $params['filearea'], $params['itemid'], $params['filepath'],
2763                      $params['filename']))) {
2764                  $file->set_missingsource();
2765              } else {
2766                  $file->set_synchronized($storedfile->get_contenthash(), $storedfile->get_filesize(), 0, $storedfile->get_timemodified());
2767              }
2768              return true;
2769          }
2770  
2771          return false;
2772      }
2773  
2774      /**
2775       * Build draft file's source field
2776       *
2777       * {@link file_restore_source_field_from_draft_file()}
2778       * XXX: This is a hack for file manager (MDL-28666)
2779       * For newly created  draft files we have to construct
2780       * source filed in php serialized data format.
2781       * File manager needs to know the original file information before copying
2782       * to draft area, so we append these information in mdl_files.source field
2783       *
2784       * @param string $source
2785       * @return string serialised source field
2786       */
2787      public static function build_source_field($source) {
2788          $sourcefield = new stdClass;
2789          $sourcefield->source = $source;
2790          return serialize($sourcefield);
2791      }
2792  
2793      /**
2794       * Prepares the repository to be cached. Implements method from cacheable_object interface.
2795       *
2796       * @return array
2797       */
2798      public function prepare_to_cache() {
2799          return array(
2800              'class' => get_class($this),
2801              'id' => $this->id,
2802              'ctxid' => $this->context->id,
2803              'options' => $this->options,
2804              'readonly' => $this->readonly
2805          );
2806      }
2807  
2808      /**
2809       * Restores the repository from cache. Implements method from cacheable_object interface.
2810       *
2811       * @return array
2812       */
2813      public static function wake_from_cache($data) {
2814          $classname = $data['class'];
2815          return new $classname($data['id'], $data['ctxid'], $data['options'], $data['readonly']);
2816      }
2817  
2818      /**
2819       * Gets a file relative to this file in the repository and sends it to the browser.
2820       * Used to allow relative file linking within a repository without creating file records
2821       * for linked files
2822       *
2823       * Repositories that overwrite this must be very careful - see filesystem repository for example.
2824       *
2825       * @param stored_file $mainfile The main file we are trying to access relative files for.
2826       * @param string $relativepath the relative path to the file we are trying to access.
2827       *
2828       */
2829      public function send_relative_file(stored_file $mainfile, $relativepath) {
2830          // This repository hasn't implemented this so send_file_not_found.
2831          send_file_not_found();
2832      }
2833  
2834      /**
2835       * helper function to check if the repository supports send_relative_file.
2836       *
2837       * @return true|false
2838       */
2839      public function supports_relative_file() {
2840          return false;
2841      }
2842  
2843      /**
2844       * Helper function to indicate if this repository uses post requests for uploading files.
2845       *
2846       * @deprecated since Moodle 3.2, 3.1.1, 3.0.5
2847       * @return bool
2848       */
2849      public function uses_post_requests() {
2850          debugging('The method repository::uses_post_requests() is deprecated and must not be used anymore.', DEBUG_DEVELOPER);
2851          return false;
2852      }
2853  
2854      /**
2855       * Generate a secret key to be used for passing sensitive information around.
2856       *
2857       * @return string repository secret key.
2858       */
2859      final static public function get_secret_key() {
2860          global $CFG;
2861  
2862          if (!isset($CFG->reposecretkey)) {
2863              set_config('reposecretkey', time() . random_string(32));
2864          }
2865          return $CFG->reposecretkey;
2866      }
2867  }
2868  
2869  /**
2870   * Exception class for repository api
2871   *
2872   * @since Moodle 2.0
2873   * @package   core_repository
2874   * @copyright 2009 Dongsheng Cai {@link http://dongsheng.org}
2875   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
2876   */
2877  class repository_exception extends moodle_exception {
2878  }
2879  
2880  /**
2881   * This is a class used to define a repository instance form
2882   *
2883   * @since Moodle 2.0
2884   * @package   core_repository
2885   * @copyright 2009 Dongsheng Cai {@link http://dongsheng.org}
2886   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
2887   */
2888  final class repository_instance_form extends moodleform {
2889      /** @var stdClass repository instance */
2890      protected $instance;
2891      /** @var string repository plugin type */
2892      protected $plugin;
2893      /** @var string repository type ID */
2894      protected $typeid;
2895      /** @var string repository context ID */
2896      protected $contextid;
2897  
2898      /**
2899       * Added defaults to moodle form
2900       */
2901      protected function add_defaults() {
2902          $mform =& $this->_form;
2903          $strrequired = get_string('required');
2904  
2905          $mform->addElement('hidden', 'edit',  ($this->instance) ? $this->instance->id : 0);
2906          $mform->setType('edit', PARAM_INT);
2907          $mform->addElement('hidden', 'new',   $this->plugin);
2908          $mform->setType('new', PARAM_ALPHANUMEXT);
2909          $mform->addElement('hidden', 'plugin', $this->plugin);
2910          $mform->setType('plugin', PARAM_PLUGIN);
2911          $mform->addElement('hidden', 'typeid', $this->typeid);
2912          $mform->setType('typeid', PARAM_INT);
2913          $mform->addElement('hidden', 'contextid', $this->contextid);
2914          $mform->setType('contextid', PARAM_INT);
2915  
2916          $mform->addElement('text', 'name', get_string('name'), 'maxlength="100" size="30"');
2917          $mform->addRule('name', $strrequired, 'required', null, 'client');
2918          $mform->setType('name', PARAM_TEXT);
2919      }
2920  
2921      /**
2922       * Define moodle form elements
2923       */
2924      public function definition() {
2925          global $CFG;
2926          // type of plugin, string
2927          $this->plugin = $this->_customdata['plugin'];
2928          $this->typeid = $this->_customdata['typeid'];
2929          $this->contextid = $this->_customdata['contextid'];
2930          $this->instance = (isset($this->_customdata['instance'])
2931                  && is_subclass_of($this->_customdata['instance'], 'repository'))
2932              ? $this->_customdata['instance'] : null;
2933  
2934          $mform =& $this->_form;
2935  
2936          $this->add_defaults();
2937  
2938          // Add instance config options.
2939          $result = repository::static_function($this->plugin, 'instance_config_form', $mform);
2940          if ($result === false) {
2941              // Remove the name element if no other config options.
2942              $mform->removeElement('name');
2943          }
2944          if ($this->instance) {
2945              $data = array();
2946              $data['name'] = $this->instance->name;
2947              if (!$this->instance->readonly) {
2948                  // and set the data if we have some.
2949                  foreach ($this->instance->get_instance_option_names() as $config) {
2950                      if (!empty($this->instance->options[$config])) {
2951                          $data[$config] = $this->instance->options[$config];
2952                       } else {
2953                          $data[$config] = '';
2954                       }
2955                  }
2956              }
2957              $this->set_data($data);
2958          }
2959  
2960          if ($result === false) {
2961              $mform->addElement('cancel');
2962          } else {
2963              $this->add_action_buttons(true, get_string('save','repository'));
2964          }
2965      }
2966  
2967      /**
2968       * Validate moodle form data
2969       *
2970       * @param array $data form data
2971       * @param array $files files in form
2972       * @return array errors
2973       */
2974      public function validation($data, $files) {
2975          global $DB;
2976          $errors = array();
2977          $plugin = $this->_customdata['plugin'];
2978          $instance = (isset($this->_customdata['instance'])
2979                  && is_subclass_of($this->_customdata['instance'], 'repository'))
2980              ? $this->_customdata['instance'] : null;
2981  
2982          if (!$instance) {
2983              $errors = repository::static_function($plugin, 'instance_form_validation', $this, $data, $errors);
2984          } else {
2985              $errors = $instance->instance_form_validation($this, $data, $errors);
2986          }
2987  
2988          $sql = "SELECT count('x')
2989                    FROM {repository_instances} i, {repository} r
2990                   WHERE r.type=:plugin AND r.id=i.typeid AND i.name=:name AND i.contextid=:contextid";
2991          $params = array('name' => $data['name'], 'plugin' => $this->plugin, 'contextid' => $this->contextid);
2992          if ($instance) {
2993              $sql .= ' AND i.id != :instanceid';
2994              $params['instanceid'] = $instance->id;
2995          }
2996          if ($DB->count_records_sql($sql, $params) > 0) {
2997              $errors['name'] = get_string('erroruniquename', 'repository');
2998          }
2999  
3000          return $errors;
3001      }
3002  }
3003  
3004  /**
3005   * This is a class used to define a repository type setting form
3006   *
3007   * @since Moodle 2.0
3008   * @package   core_repository
3009   * @copyright 2009 Dongsheng Cai {@link http://dongsheng.org}
3010   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
3011   */
3012  final class repository_type_form extends moodleform {
3013      /** @var stdClass repository instance */
3014      protected $instance;
3015      /** @var string repository plugin name */
3016      protected $plugin;
3017      /** @var string action */
3018      protected $action;
3019      /** @var string plugin name */
3020      protected $pluginname;
3021  
3022      /**
3023       * Definition of the moodleform
3024       */
3025      public function definition() {
3026          global $CFG;
3027          // type of plugin, string
3028          $this->plugin = $this->_customdata['plugin'];
3029          $this->instance = (isset($this->_customdata['instance'])
3030                  && is_a($this->_customdata['instance'], 'repository_type'))
3031              ? $this->_customdata['instance'] : null;
3032  
3033          $this->action = $this->_customdata['action'];
3034          $this->pluginname = $this->_customdata['pluginname'];
3035          $mform =& $this->_form;
3036          $strrequired = get_string('required');
3037  
3038          $mform->addElement('hidden', 'action', $this->action);
3039          $mform->setType('action', PARAM_TEXT);
3040          $mform->addElement('hidden', 'repos', $this->plugin);
3041          $mform->setType('repos', PARAM_PLUGIN);
3042  
3043          // let the plugin add its specific fields
3044          $classname = 'repository_' . $this->plugin;
3045          require_once($CFG->dirroot . '/repository/' . $this->plugin . '/lib.php');
3046          //add "enable course/user instances" checkboxes if multiple instances are allowed
3047          $instanceoptionnames = repository::static_function($this->plugin, 'get_instance_option_names');
3048  
3049          $result = call_user_func(array($classname, 'type_config_form'), $mform, $classname);
3050  
3051          if (!empty($instanceoptionnames)) {
3052              $sm = get_string_manager();
3053              $component = 'repository';
3054              if ($sm->string_exists('enablecourseinstances', 'repository_' . $this->plugin)) {
3055                  $component .= ('_' . $this->plugin);
3056              }
3057              $mform->addElement('checkbox', 'enablecourseinstances', get_string('enablecourseinstances', $component));
3058              $mform->setType('enablecourseinstances', PARAM_BOOL);
3059  
3060              $component = 'repository';
3061              if ($sm->string_exists('enableuserinstances', 'repository_' . $this->plugin)) {
3062                  $component .= ('_' . $this->plugin);
3063              }
3064              $mform->addElement('checkbox', 'enableuserinstances', get_string('enableuserinstances', $component));
3065              $mform->setType('enableuserinstances', PARAM_BOOL);
3066          }
3067  
3068          // set the data if we have some.
3069          if ($this->instance) {
3070              $data = array();
3071              $option_names = call_user_func(array($classname,'get_type_option_names'));
3072              if (!empty($instanceoptionnames)){
3073                  $option_names[] = 'enablecourseinstances';
3074                  $option_names[] = 'enableuserinstances';
3075              }
3076  
3077              $instanceoptions = $this->instance->get_options();
3078              foreach ($option_names as $config) {
3079                  if (!empty($instanceoptions[$config])) {
3080                      $data[$config] = $instanceoptions[$config];
3081                  } else {
3082                      $data[$config] = '';
3083                  }
3084              }
3085              // XXX: set plugin name for plugins which doesn't have muliti instances
3086              if (empty($instanceoptionnames)){
3087                  $data['pluginname'] = $this->pluginname;
3088              }
3089              $this->set_data($data);
3090          }
3091  
3092          $this->add_action_buttons(true, get_string('save','repository'));
3093      }
3094  
3095      /**
3096       * Validate moodle form data
3097       *
3098       * @param array $data moodle form data
3099       * @param array $files
3100       * @return array errors
3101       */
3102      public function validation($data, $files) {
3103          $errors = array();
3104          $plugin = $this->_customdata['plugin'];
3105          $instance = (isset($this->_customdata['instance'])
3106                  && is_subclass_of($this->_customdata['instance'], 'repository'))
3107              ? $this->_customdata['instance'] : null;
3108          if (!$instance) {
3109              $errors = repository::static_function($plugin, 'type_form_validation', $this, $data, $errors);
3110          } else {
3111              $errors = $instance->type_form_validation($this, $data, $errors);
3112          }
3113  
3114          return $errors;
3115      }
3116  }
3117  
3118  /**
3119   * Generate all options needed by filepicker
3120   *
3121   * @param stdClass $args including following keys
3122   *          context
3123   *          accepted_types
3124   *          return_types
3125   *
3126   * @return stdClass the list of repository instances, including meta infomation, containing the following keys
3127   *          externallink
3128   *          repositories
3129   *          accepted_types
3130   */
3131  function initialise_filepicker($args) {
3132      global $CFG, $USER, $PAGE;
3133      static $templatesinitialized = array();
3134      require_once($CFG->libdir . '/licenselib.php');
3135  
3136      $return = new stdClass();
3137  
3138      $licenses = license_manager::get_licenses();
3139  
3140      if (!empty($CFG->sitedefaultlicense)) {
3141          $return->defaultlicense = $CFG->sitedefaultlicense;
3142      }
3143  
3144      $return->licenses = $licenses;
3145  
3146      $return->author = fullname($USER);
3147  
3148      if (empty($args->context)) {
3149          $context = $PAGE->context;
3150      } else {
3151          $context = $args->context;
3152      }
3153      $disable_types = array();
3154      if (!empty($args->disable_types)) {
3155          $disable_types = $args->disable_types;
3156      }
3157  
3158      $user_context = context_user::instance($USER->id);
3159  
3160      list($context, $course, $cm) = get_context_info_array($context->id);
3161      $contexts = array($user_context, context_system::instance());
3162      if (!empty($course)) {
3163          // adding course context
3164          $contexts[] = context_course::instance($course->id);
3165      }
3166      $externallink = (int)get_config(null, 'repositoryallowexternallinks');
3167      $repositories = repository::get_instances(array(
3168          'context'=>$contexts,
3169          'currentcontext'=> $context,
3170          'accepted_types'=>$args->accepted_types,
3171          'return_types'=>$args->return_types,
3172          'disable_types'=>$disable_types
3173      ));
3174  
3175      $return->repositories = array();
3176  
3177      if (empty($externallink)) {
3178          $return->externallink = false;
3179      } else {
3180          $return->externallink = true;
3181      }
3182  
3183      $return->rememberuserlicensepref = (bool) get_config(null, 'rememberuserlicensepref');
3184  
3185      $return->userprefs = array();
3186      $return->userprefs['recentrepository'] = get_user_preferences('filepicker_recentrepository', '');
3187      $return->userprefs['recentlicense'] = get_user_preferences('filepicker_recentlicense', '');
3188      $return->userprefs['recentviewmode'] = get_user_preferences('filepicker_recentviewmode', '');
3189  
3190      user_preference_allow_ajax_update('filepicker_recentrepository', PARAM_INT);
3191      user_preference_allow_ajax_update('filepicker_recentlicense', PARAM_SAFEDIR);
3192      user_preference_allow_ajax_update('filepicker_recentviewmode', PARAM_INT);
3193  
3194  
3195      // provided by form element
3196      $return->accepted_types = file_get_typegroup('extension', $args->accepted_types);
3197      $return->return_types = $args->return_types;
3198      $templates = array();
3199      foreach ($repositories as $repository) {
3200          $meta = $repository->get_meta();
3201          // Please note that the array keys for repositories are used within
3202          // JavaScript a lot, the key NEEDS to be the repository id.
3203          $return->repositories[$repository->id] = $meta;
3204          // Register custom repository template if it has one
3205          if(method_exists($repository, 'get_upload_template') && !array_key_exists('uploadform_' . $meta->type, $templatesinitialized)) {
3206              $templates['uploadform_' . $meta->type] = $repository->get_upload_template();
3207              $templatesinitialized['uploadform_' . $meta->type] = true;
3208          }
3209      }
3210      if (!array_key_exists('core', $templatesinitialized)) {
3211          // we need to send each filepicker template to the browser just once
3212          $fprenderer = $PAGE->get_renderer('core', 'files');
3213          $templates = array_merge($templates, $fprenderer->filepicker_js_templates());
3214          $templatesinitialized['core'] = true;
3215      }
3216      if (sizeof($templates)) {
3217          $PAGE->requires->js_init_call('M.core_filepicker.set_templates', array($templates), true);
3218      }
3219      return $return;
3220  }
3221  
3222  /**
3223   * Convenience function to handle deletion of files.
3224   *
3225   * @param object $context The context where the delete is called
3226   * @param string $component component
3227   * @param string $filearea filearea
3228   * @param int $itemid the item id
3229   * @param array $files Array of files object with each item having filename/filepath as values
3230   * @return array $return Array of strings matching up to the parent directory of the deleted files
3231   * @throws coding_exception
3232   */
3233  function repository_delete_selected_files($context, string $component, string $filearea, $itemid, array $files) {
3234      $fs = get_file_storage();
3235      $return = [];
3236  
3237      foreach ($files as $selectedfile) {
3238          $filename = clean_filename($selectedfile->filename);
3239          $filepath = clean_param($selectedfile->filepath, PARAM_PATH);
3240          $filepath = file_correct_filepath($filepath);
3241  
3242          if ($storedfile = $fs->get_file($context->id, $component, $filearea, $itemid, $filepath, $filename)) {
3243              $parentpath = $storedfile->get_parent_directory()->get_filepath();
3244              if ($storedfile->is_directory()) {
3245                  $files = $fs->get_directory_files($context->id, $component, $filearea, $itemid, $filepath, true);
3246                  foreach ($files as $file) {
3247                      $file->delete();
3248                  }
3249                  $storedfile->delete();
3250                  $return[$parentpath] = "";
3251              } else {
3252                  if ($result = $storedfile->delete()) {
3253                      $return[$parentpath] = "";
3254                  }
3255              }
3256          }
3257      }
3258  
3259      return $return;
3260  }
3261  
3262  /**
3263   * Convenience function to handle deletion of files.
3264   *
3265   * @param object $context The context where the delete is called
3266   * @param string $component component
3267   * @param string $filearea filearea
3268   * @param int $itemid the item id
3269   * @param array $files Array of files object with each item having filename/filepath as values
3270   * @return array $return Array of strings matching up to the parent directory of the deleted files
3271   * @throws coding_exception
3272   */
3273  function repository_download_selected_files($context, string $component, string $filearea, $itemid, array $files) {
3274      global $USER;
3275      $return = false;
3276  
3277      $zipper = get_file_packer('application/zip');
3278      $fs = get_file_storage();
3279      // Archive compressed file to an unused draft area.
3280      $newdraftitemid = file_get_unused_draft_itemid();
3281      $filestoarchive = [];
3282  
3283      foreach ($files as $selectedfile) {
3284          $filename = $selectedfile->filename ? clean_filename($selectedfile->filename) : '.'; // Default to '.' for root.
3285          $filepath = clean_param($selectedfile->filepath, PARAM_PATH); // Default to '/' for downloadall.
3286          $filepath = file_correct_filepath($filepath);
3287          $area = file_get_draft_area_info($itemid, $filepath);
3288          if ($area['filecount'] == 0 && $area['foldercount'] == 0) {
3289              continue;
3290          }
3291  
3292          $storedfile = $fs->get_file($context->id, $component, $filearea, $itemid, $filepath, $filename);
3293          // If it is empty we are downloading a directory.
3294          $archivefile = $storedfile->get_filename();
3295          if (!$filename || $filename == '.' ) {
3296              $foldername = explode('/', trim($filepath, '/'));
3297              $folder = trim(array_pop($foldername), '/');
3298              $archivefile = $folder ?? '/';
3299          }
3300  
3301          $filestoarchive[$archivefile] = $storedfile;
3302      }
3303      $zippedfile = get_string('files') . '.zip';
3304      if ($newfile =
3305          $zipper->archive_to_storage(
3306              $filestoarchive,
3307              $context->id,
3308              $component,
3309              $filearea,
3310              $newdraftitemid,
3311              "/",
3312              $zippedfile, $USER->id)
3313      ) {
3314          $return = new stdClass();
3315          $return->fileurl = moodle_url::make_draftfile_url($newdraftitemid, '/', $zippedfile)->out();
3316          $return->filepath = $filepath;
3317      }
3318  
3319      return $return;
3320  }