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See Release Notes

  • Bug fixes for general core bugs in 3.11.x will end 14 Nov 2022 (12 months plus 6 months extension).
  • Bug fixes for security issues in 3.11.x will end 13 Nov 2023 (18 months plus 12 months extension).
  • PHP version: minimum PHP 7.3.0 Note: minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is supported too.
/repository/ -> lib.php (source)

Differences Between: [Versions 310 and 311] [Versions 311 and 400] [Versions 311 and 401] [Versions 38 and 311] [Versions 39 and 311]

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