repository/lib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18
  19 /**
  20  * This file contains classes used to manage the repository plugins in Moodle
  21  * and was introduced as part of the changes occuring in Moodle 2.0
  22  *
  23  * @since 2.0
  24  * @package    core
  25  * @subpackage repository
  26  * @copyright  2009 Dongsheng Cai <dongsheng@moodle.com>
  27  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  28  */
  29
  30 require_once(dirname(dirname(__FILE__)) . '/config.php');
  31 require_once($CFG->libdir . '/filelib.php');
  32 require_once($CFG->libdir . '/formslib.php');
  33
  34 define('FILE_EXTERNAL', 1);
  35 define('FILE_INTERNAL', 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 moodlecore
  54  * @subpackage repository
  55  * @copyright 2009 Jerome Mouneyrac
  56  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  57  */
  58 class repository_type {
  59
  60
  61     /**
  62      * Type name (no whitespace) - A type name is unique
  63      * Note: for a user-friendly type name see get_readablename()
  64      * @var String
  65      */
  66     private $_typename;
  67
  68
  69     /**
  70      * Options of this type
  71      * They are general options that any instance of this type would share
  72      * e.g. API key
  73      * These options are saved in config_plugin table
  74      * @var array
  75      */
  76     private $_options;
  77
  78
  79     /**
  80      * Is the repository type visible or hidden
  81      * If false (hidden): no instances can be created, edited, deleted, showned , used...
  82      * @var boolean
  83      */
  84     private $_visible;
  85
  86
  87     /**
  88      * 0 => not ordered, 1 => first position, 2 => second position...
  89      * A not order type would appear in first position (should never happened)
  90      * @var integer
  91      */
  92     private $_sortorder;
  93
  94      /**
  95      * Return if the instance is visible in a context
  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 objet $context - context
  99      * @return boolean
 100      */
 101     public function get_contextvisibility($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      * @global object $CFG
 121      * @param integer $typename
 122      * @param array $typeoptions
 123      * @param boolean $visible
 124      * @param integer $sortorder (don't really need set, it will be during create() call)
 125      */
 126     public function __construct($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      * @return String the type name
 166      */
 167     public function get_typename() {
 168         return $this->_typename;
 169     }
 170
 171     /**
 172      * Return a human readable and user-friendly type name
 173      * @return string user-friendly type name
 174      */
 175     public function get_readablename() {
 176         return get_string('pluginname','repository_'.$this->_typename);
 177     }
 178
 179     /**
 180      * Return general options
 181      * @return array the general options
 182      */
 183     public function get_options() {
 184         return $this->_options;
 185     }
 186
 187     /**
 188      * Return visibility
 189      * @return boolean
 190      */
 191     public function get_visible() {
 192         return $this->_visible;
 193     }
 194
 195     /**
 196      * Return order / position of display in the file picker
 197      * @return integer
 198      */
 199     public function get_sortorder() {
 200         return $this->_sortorder;
 201     }
 202
 203     /**
 204      * Create a repository type (the type name must not already exist)
 205      * @param boolean throw exception?
 206      * @return mixed return int if create successfully, return false if
 207      *         any errors
 208      * @global object $DB
 209      */
 210     public function create($silent = false) {
 211         global $DB;
 212
 213         //check that $type has been set
 214         $timmedtype = trim($this->_typename);
 215         if (empty($timmedtype)) {
 216             throw new repository_exception('emptytype', 'repository');
 217         }
 218
 219         //set sortorder as the last position in the list
 220         if (!isset($this->_sortorder) || $this->_sortorder == 0 ) {
 221             $sql = "SELECT MAX(sortorder) FROM {repository}";
 222             $this->_sortorder = 1 + $DB->get_field_sql($sql);
 223         }
 224
 225         //only create a new type if it doesn't already exist
 226         $existingtype = $DB->get_record('repository', array('type'=>$this->_typename));
 227         if (!$existingtype) {
 228             //create the type
 229             $newtype = new stdClass();
 230             $newtype->type = $this->_typename;
 231             $newtype->visible = $this->_visible;
 232             $newtype->sortorder = $this->_sortorder;
 233             $plugin_id = $DB->insert_record('repository', $newtype);
 234             //save the options in DB
 235             $this->update_options();
 236
 237             $instanceoptionnames = repository::static_function($this->_typename, 'get_instance_option_names');
 238
 239             //if the plugin type has no multiple instance (e.g. has no instance option name) so it wont
 240             //be possible for the administrator to create a instance
 241             //in this case we need to create an instance
 242             if (empty($instanceoptionnames)) {
 243                 $instanceoptions = array();
 244                 if (empty($this->_options['pluginname'])) {
 245                     // when moodle trying to install some repo plugin automatically
 246                     // this option will be empty, get it from language string when display
 247                     $instanceoptions['name'] = '';
 248                 } else {
 249                     // when admin trying to add a plugin manually, he will type a name
 250                     // for it
 251                     $instanceoptions['name'] = $this->_options['pluginname'];
 252                 }
 253                 repository::static_function($this->_typename, 'create', $this->_typename, 0, get_system_context(), $instanceoptions);
 254             }
 255             //run plugin_init function
 256             if (!repository::static_function($this->_typename, 'plugin_init')) {
 257                 if (!$silent) {
 258                     throw new repository_exception('cannotinitplugin', 'repository');
 259                 }
 260             }
 261
 262             if(!empty($plugin_id)) {
 263                 // return plugin_id if create successfully
 264                 return $plugin_id;
 265             } else {
 266                 return false;
 267             }
 268
 269         } else {
 270             if (!$silent) {
 271                 throw new repository_exception('existingrepository', 'repository');
 272             }
 273             // If plugin existed, return false, tell caller no new plugins were created.
 274             return false;
 275         }
 276     }
 277
 278
 279     /**
 280      * Update plugin options into the config_plugin table
 281      * @param array $options
 282      * @return boolean
 283      */
 284     public function update_options($options = null) {
 285         global $DB;
 286         $classname = 'repository_' . $this->_typename;
 287         $instanceoptions = repository::static_function($this->_typename, 'get_instance_option_names');
 288         if (empty($instanceoptions)) {
 289             // update repository instance name if this plugin type doesn't have muliti instances
 290             $params = array();
 291             $params['type'] = $this->_typename;
 292             $instances = repository::get_instances($params);
 293             $instance = array_pop($instances);
 294             if ($instance) {
 295                 $DB->set_field('repository_instances', 'name', $options['pluginname'], array('id'=>$instance->id));
 296             }
 297             unset($options['pluginname']);
 298         }
 299
 300         if (!empty($options)) {
 301             $this->_options = $options;
 302         }
 303
 304         foreach ($this->_options as $name => $value) {
 305             set_config($name, $value, $this->_typename);
 306         }
 307
 308         return true;
 309     }
 310
 311     /**
 312      * Update visible database field with the value given as parameter
 313      * or with the visible value of this object
 314      * This function is private.
 315      * For public access, have a look to switch_and_update_visibility()
 316      * @global object $DB
 317      * @param boolean $visible
 318      * @return boolean
 319      */
 320     private function update_visible($visible = null) {
 321         global $DB;
 322
 323         if (!empty($visible)) {
 324             $this->_visible = $visible;
 325         }
 326         else if (!isset($this->_visible)) {
 327             throw new repository_exception('updateemptyvisible', 'repository');
 328         }
 329
 330         return $DB->set_field('repository', 'visible', $this->_visible, array('type'=>$this->_typename));
 331     }
 332
 333     /**
 334      * Update database sortorder field with the value given as parameter
 335      * or with the sortorder value of this object
 336      * This function is private.
 337      * For public access, have a look to move_order()
 338      * @global object $DB
 339      * @param integer $sortorder
 340      * @return boolean
 341      */
 342     private function update_sortorder($sortorder = null) {
 343         global $DB;
 344
 345         if (!empty($sortorder) && $sortorder!=0) {
 346             $this->_sortorder = $sortorder;
 347         }
 348         //if sortorder is not set, we set it as the ;ast position in the list
 349         else if (!isset($this->_sortorder) || $this->_sortorder == 0 ) {
 350             $sql = "SELECT MAX(sortorder) FROM {repository}";
 351             $this->_sortorder = 1 + $DB->get_field_sql($sql);
 352         }
 353
 354         return $DB->set_field('repository', 'sortorder', $this->_sortorder, array('type'=>$this->_typename));
 355     }
 356
 357     /**
 358      * Change order of the type with its adjacent upper or downer type
 359      * (database fields are updated)
 360      * Algorithm details:
 361      * 1. retrieve all types in an array. This array is sorted by sortorder,
 362      * and the array keys start from 0 to X (incremented by 1)
 363      * 2. switch sortorder values of this type and its adjacent type
 364      * @global object $DB
 365      * @param string $move "up" or "down"
 366      */
 367     public function move_order($move) {
 368         global $DB;
 369
 370         $types = repository::get_types();    // retrieve all types
 371
 372     /// retrieve this type into the returned array
 373         $i = 0;
 374         while (!isset($indice) && $i<count($types)) {
 375             if ($types[$i]->get_typename() == $this->_typename) {
 376                 $indice = $i;
 377             }
 378             $i++;
 379         }
 380
 381     /// retrieve adjacent indice
 382         switch ($move) {
 383             case "up":
 384                 $adjacentindice = $indice - 1;
 385             break;
 386             case "down":
 387                 $adjacentindice = $indice + 1;
 388             break;
 389             default:
 390             throw new repository_exception('movenotdefined', 'repository');
 391         }
 392
 393         //switch sortorder of this type and the adjacent type
 394         //TODO: we could reset sortorder for all types. This is not as good in performance term, but
 395         //that prevent from wrong behaviour on a screwed database. As performance are not important in this particular case
 396         //it worth to change the algo.
 397         if ($adjacentindice>=0 && !empty($types[$adjacentindice])) {
 398             $DB->set_field('repository', 'sortorder', $this->_sortorder, array('type'=>$types[$adjacentindice]->get_typename()));
 399             $this->update_sortorder($types[$adjacentindice]->get_sortorder());
 400         }
 401     }
 402
 403     /**
 404      * 1. Change visibility to the value chosen
 405      *
 406      * 2. Update the type
 407      * @return boolean
 408      */
 409     public function update_visibility($visible = null) {
 410         if (is_bool($visible)) {
 411             $this->_visible = $visible;
 412         } else {
 413             $this->_visible = !$this->_visible;
 414         }
 415         return $this->update_visible();
 416     }
 417
 418
 419     /**
 420      * Delete a repository_type (general options are removed from config_plugin
 421      * table, and all instances are deleted)
 422      * @global object $DB
 423      * @return boolean
 424      */
 425     public function delete() {
 426         global $DB;
 427
 428         //delete all instances of this type
 429         $params = array();
 430         $params['context'] = array();
 431         $params['onlyvisible'] = false;
 432         $params['type'] = $this->_typename;
 433         $instances = repository::get_instances($params);
 434         foreach ($instances as $instance) {
 435             $instance->delete();
 436         }
 437
 438         //delete all general options
 439         foreach ($this->_options as $name => $value) {
 440             set_config($name, null, $this->_typename);
 441         }
 442
 443         return $DB->delete_records('repository', array('type' => $this->_typename));
 444     }
 445 }
 446
 447 /**
 448  * This is the base class of the repository class
 449  *
 450  * To use repository plugin, see:
 451  * http://docs.moodle.org/en/Development:Repository_How_to_Create_Plugin
 452  * class repository is an abstract class, some functions must be implemented in subclass.
 453  * See an example: repository/boxnet/lib.php
 454  *
 455  * A few notes:
 456  *   // for ajax file picker, this will print a json string to tell file picker
 457  *   // how to build a login form
 458  *   $repo->print_login();
 459  *   // for ajax file picker, this will return a files list.
 460  *   $repo->get_listing();
 461  *   // this function will be used for non-javascript version.
 462  *   $repo->print_listing();
 463  *   // print a search box
 464  *   $repo->print_search();
 465  *
 466  * @package moodlecore
 467  * @subpackage repository
 468  * @copyright 2009 Dongsheng Cai <dongsheng@moodle.com>
 469  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 470  */
 471 abstract class repository {
 472     // $disabled can be set to true to disable a plugin by force
 473     // example: self::$disabled = true
 474     public $disabled = false;
 475     public $id;
 476     /** @var object current context */
 477     public $context;
 478     public $options;
 479     public $readonly;
 480     public $returntypes;
 481     /** @var object repository instance database record */
 482     public $instance;
 483     /**
 484      * 1. Initialize context and options
 485      * 2. Accept necessary parameters
 486      *
 487      * @param integer $repositoryid repository instance id
 488      * @param integer|object a context id or context object
 489      * @param array $options repository options
 490      */
 491     public function __construct($repositoryid, $context = SYSCONTEXTID, $options = array(), $readonly = 0) {
 492         global $DB;
 493         $this->id = $repositoryid;
 494         if (is_object($context)) {
 495             $this->context = $context;
 496         } else {
 497             $this->context = get_context_instance_by_id($context);
 498         }
 499         $this->instance = $DB->get_record('repository_instances', array('id'=>$this->id));
 500         $this->readonly = $readonly;
 501         $this->options = array();
 502
 503         if (is_array($options)) {
 504             $options = array_merge($this->get_option(), $options);
 505         } else {
 506             $options = $this->get_option();
 507         }
 508         foreach ($options as $n => $v) {
 509             $this->options[$n] = $v;
 510         }
 511         $this->name = $this->get_name();
 512         $this->returntypes = $this->supported_returntypes();
 513         $this->super_called = true;
 514     }
 515
 516     /**
 517      * Get a repository type object by a given type name.
 518      * @global object $DB
 519      * @param string $typename the repository type name
 520      * @return repository_type|bool
 521      */
 522     public static function get_type_by_typename($typename) {
 523         global $DB;
 524
 525         if (!$record = $DB->get_record('repository',array('type' => $typename))) {
 526             return false;
 527         }
 528
 529         return new repository_type($typename, (array)get_config($typename), $record->visible, $record->sortorder);
 530     }
 531
 532     /**
 533      * Get the repository type by a given repository type id.
 534      * @global object $DB
 535      * @param int $id the type id
 536      * @return object
 537      */
 538     public static function get_type_by_id($id) {
 539         global $DB;
 540
 541         if (!$record = $DB->get_record('repository',array('id' => $id))) {
 542             return false;
 543         }
 544
 545         return new repository_type($record->type, (array)get_config($record->type), $record->visible, $record->sortorder);
 546     }
 547
 548     /**
 549      * Return all repository types ordered by sortorder field
 550      * first repository type in returnedarray[0], second repository type in returnedarray[1], ...
 551      * @global object $DB
 552      * @global object $CFG
 553      * @param boolean $visible can return types by visiblity, return all types if null
 554      * @return array Repository types
 555      */
 556     public static function get_types($visible=null) {
 557         global $DB, $CFG;
 558
 559         $types = array();
 560         $params = null;
 561         if (!empty($visible)) {
 562             $params = array('visible' => $visible);
 563         }
 564         if ($records = $DB->get_records('repository',$params,'sortorder')) {
 565             foreach($records as $type) {
 566                 if (file_exists($CFG->dirroot . '/repository/'. $type->type .'/lib.php')) {
 567                     $types[] = new repository_type($type->type, (array)get_config($type->type), $type->visible, $type->sortorder);
 568                 }
 569             }
 570         }
 571
 572         return $types;
 573     }
 574
 575     /**
 576      * To check if the context id is valid
 577      * @global object $USER
 578      * @param int $contextid
 579      * @return boolean
 580      */
 581     public static function check_capability($contextid, $instance) {
 582         $context = get_context_instance_by_id($contextid);
 583         $capability = has_capability('repository/'.$instance->type.':view', $context);
 584         if (!$capability) {
 585             throw new repository_exception('nopermissiontoaccess', 'repository');
 586         }
 587     }
 588
 589     /**
 590      * Return all types that you a user can create/edit and which are also visible
 591      * Note: Mostly used in order to know if at least one editable type can be set
 592      * @param object $context the context for which we want the editable types
 593      * @return array types
 594      */
 595     public static function get_editable_types($context = null) {
 596
 597         if (empty($context)) {
 598             $context = get_system_context();
 599         }
 600
 601         $types= repository::get_types(true);
 602         $editabletypes = array();
 603         foreach ($types as $type) {
 604             $instanceoptionnames = repository::static_function($type->get_typename(), 'get_instance_option_names');
 605             if (!empty($instanceoptionnames)) {
 606                 if ($type->get_contextvisibility($context)) {
 607                     $editabletypes[]=$type;
 608                 }
 609              }
 610         }
 611         return $editabletypes;
 612     }
 613
 614     /**
 615      * Return repository instances
 616      * @global object $DB
 617      * @global object $CFG
 618      * @global object $USER
 619      *
 620      * @param array $args Array containing the following keys:
 621      *           currentcontext
 622      *           context
 623      *           onlyvisible
 624      *           type
 625      *           accepted_types
 626      *           return_types
 627      *           userid
 628      *
 629      * @return array repository instances
 630      */
 631     public static function get_instances($args = array()) {
 632         global $DB, $CFG, $USER;
 633
 634         if (isset($args['currentcontext'])) {
 635             $current_context = $args['currentcontext'];
 636         } else {
 637             $current_context = null;
 638         }
 639
 640         if (!empty($args['context'])) {
 641             $contexts = $args['context'];
 642         } else {
 643             $contexts = array();
 644         }
 645
 646         $onlyvisible = isset($args['onlyvisible']) ? $args['onlyvisible'] : true;
 647         $returntypes = isset($args['return_types']) ? $args['return_types'] : 3;
 648         $type        = isset($args['type']) ? $args['type'] : null;
 649
 650         $params = array();
 651         $sql = "SELECT i.*, r.type AS repositorytype, r.sortorder, r.visible
 652                   FROM {repository} r, {repository_instances} i
 653                  WHERE i.typeid = r.id ";
 654
 655         if (!empty($args['disable_types']) && is_array($args['disable_types'])) {
 656             list($types, $p) = $DB->get_in_or_equal($args['disable_types'], SQL_PARAMS_QM, 'param0000', false);
 657             $sql .= " AND r.type $types";
 658             $params = array_merge($params, $p);
 659         }
 660
 661         if (!empty($args['userid']) && is_numeric($args['userid'])) {
 662             $sql .= " AND (i.userid = 0 or i.userid = ?)";
 663             $params[] = $args['userid'];
 664         }
 665
 666         foreach ($contexts as $context) {
 667             if (empty($firstcontext)) {
 668                 $firstcontext = true;
 669                 $sql .= " AND ((i.contextid = ?)";
 670             } else {
 671                 $sql .= " OR (i.contextid = ?)";
 672             }
 673             $params[] = $context->id;
 674         }
 675
 676         if (!empty($firstcontext)) {
 677            $sql .=')';
 678         }
 679
 680         if ($onlyvisible == true) {
 681             $sql .= " AND (r.visible = 1)";
 682         }
 683
 684         if (isset($type)) {
 685             $sql .= " AND (r.type = ?)";
 686             $params[] = $type;
 687         }
 688         $sql .= " ORDER BY r.sortorder, i.name";
 689
 690         if (!$records = $DB->get_records_sql($sql, $params)) {
 691             $records = array();
 692         }
 693
 694         $repositories = array();
 695         $ft = new filetype_parser();
 696         if (isset($args['accepted_types'])) {
 697             $accepted_types = $args['accepted_types'];
 698         } else {
 699             $accepted_types = '*';
 700         }
 701         foreach ($records as $record) {
 702             if (!file_exists($CFG->dirroot . '/repository/'. $record->repositorytype.'/lib.php')) {
 703                 continue;
 704             }
 705             require_once($CFG->dirroot . '/repository/'. $record->repositorytype.'/lib.php');
 706             $options['visible'] = $record->visible;
 707             $options['type']    = $record->repositorytype;
 708             $options['typeid']  = $record->typeid;
 709             // tell instance what file types will be accepted by file picker
 710             $classname = 'repository_' . $record->repositorytype;
 711
 712             $repository = new $classname($record->id, $record->contextid, $options, $record->readonly);
 713
 714             $is_supported = true;
 715
 716             if (empty($repository->super_called)) {
 717                 // to make sure the super construct is called
 718                 debugging('parent::__construct must be called by '.$record->repositorytype.' plugin.');
 719             } else {
 720                 // check mimetypes
 721                 if ($accepted_types !== '*' and $repository->supported_filetypes() !== '*') {
 722                     $accepted_types = $ft->get_extensions($accepted_types);
 723                     $supported_filetypes = $ft->get_extensions($repository->supported_filetypes());
 724
 725                     $is_supported = false;
 726                     foreach  ($supported_filetypes as $type) {
 727                         if (in_array($type, $accepted_types)) {
 728                             $is_supported = true;
 729                         }
 730                     }
 731
 732                 }
 733                 // check return values
 734                 if ($returntypes !== 3 and $repository->supported_returntypes() !== 3) {
 735                     $type = $repository->supported_returntypes();
 736                     if ($type & $returntypes) {
 737                         //
 738                     } else {
 739                         $is_supported = false;
 740                     }
 741                 }
 742
 743                 if (!$onlyvisible || ($repository->is_visible() && !$repository->disabled)) {
 744                     // check capability in current context
 745                     if (!empty($current_context)) {
 746                         $capability = has_capability('repository/'.$record->repositorytype.':view', $current_context);
 747                     } else {
 748                         $capability = has_capability('repository/'.$record->repositorytype.':view', get_system_context());
 749                     }
 750                     if ($record->repositorytype == 'coursefiles') {
 751                         // coursefiles plugin needs managefiles permission
 752                         $capability = $capability && has_capability('moodle/course:managefiles', $current_context);
 753                     }
 754                     if ($is_supported && $capability) {
 755                         $repositories[$repository->id] = $repository;
 756                     }
 757                 }
 758             }
 759         }
 760         return $repositories;
 761     }
 762
 763     /**
 764      * Get single repository instance
 765      * @global object $DB
 766      * @global object $CFG
 767      * @param integer $id repository id
 768      * @return object repository instance
 769      */
 770     public static function get_instance($id) {
 771         global $DB, $CFG;
 772         $sql = "SELECT i.*, r.type AS repositorytype, r.visible
 773                   FROM {repository} r
 774                   JOIN {repository_instances} i ON i.typeid = r.id
 775                  WHERE i.id = ?";
 776
 777         if (!$instance = $DB->get_record_sql($sql, array($id))) {
 778             return false;
 779         }
 780         require_once($CFG->dirroot . '/repository/'. $instance->repositorytype.'/lib.php');
 781         $classname = 'repository_' . $instance->repositorytype;
 782         $options['typeid'] = $instance->typeid;
 783         $options['type']   = $instance->repositorytype;
 784         $options['name']   = $instance->name;
 785         $obj = new $classname($instance->id, $instance->contextid, $options, $instance->readonly);
 786         if (empty($obj->super_called)) {
 787             debugging('parent::__construct must be called by '.$classname.' plugin.');
 788         }
 789         return $obj;
 790     }
 791
 792     /**
 793      * Call a static function. Any additional arguments than plugin and function will be passed through.
 794      * @global object $CFG
 795      * @param string $plugin
 796      * @param string $function
 797      * @return mixed
 798      */
 799     public static function static_function($plugin, $function) {
 800         global $CFG;
 801
 802         //check that the plugin exists
 803         $typedirectory = $CFG->dirroot . '/repository/'. $plugin . '/lib.php';
 804         if (!file_exists($typedirectory)) {
 805             //throw new repository_exception('invalidplugin', 'repository');
 806             return false;
 807         }
 808
 809         $pname = null;
 810         if (is_object($plugin) || is_array($plugin)) {
 811             $plugin = (object)$plugin;
 812             $pname = $plugin->name;
 813         } else {
 814             $pname = $plugin;
 815         }
 816
 817         $args = func_get_args();
 818         if (count($args) <= 2) {
 819             $args = array();
 820         } else {
 821             array_shift($args);
 822             array_shift($args);
 823         }
 824
 825         require_once($typedirectory);
 826         return call_user_func_array(array('repository_' . $plugin, $function), $args);
 827     }
 828
 829     /**
 830      * Move file from download folder to file pool using FILE API
 831      * @global object $DB
 832      * @global object $CFG
 833      * @global object $USER
 834      * @global object $OUTPUT
 835      * @param string $thefile file path in download folder
 836      * @param object $record
 837      * @return array containing the following keys:
 838      *           icon
 839      *           file
 840      *           id
 841      *           url
 842      */
 843     public static function move_to_filepool($thefile, $record) {
 844         global $DB, $CFG, $USER, $OUTPUT;
 845         if ($record->filepath !== '/') {
 846             $record->filepath = trim($record->filepath, '/');
 847             $record->filepath = '/'.$record->filepath.'/';
 848         }
 849         $context = get_context_instance(CONTEXT_USER, $USER->id);
 850         $now = time();
 851
 852         $record->contextid = $context->id;
 853         $record->component = 'user';
 854         $record->filearea  = 'draft';
 855         $record->timecreated  = $now;
 856         $record->timemodified = $now;
 857         $record->userid       = $USER->id;
 858         $record->mimetype     = mimeinfo('type', $thefile);
 859         if(!is_numeric($record->itemid)) {
 860             $record->itemid = 0;
 861         }
 862         $fs = get_file_storage();
 863         if ($existingfile = $fs->get_file($context->id, $record->component, $record->filearea, $record->itemid, $record->filepath, $record->filename)) {
 864             throw new moodle_exception('fileexists');
 865         }
 866         if ($file = $fs->create_file_from_pathname($record, $thefile)) {
 867             if (empty($CFG->repository_no_delete)) {
 868                 $delete = unlink($thefile);
 869                 unset($CFG->repository_no_delete);
 870             }
 871             return array(
 872                 'url'=>moodle_url::make_draftfile_url($file->get_itemid(), $file->get_filepath(), $file->get_filename())->out(),
 873                 'id'=>$file->get_itemid(),
 874                 'file'=>$file->get_filename(),
 875                 'icon' => $OUTPUT->pix_url(file_extension_icon($thefile, 32))->out(),
 876             );
 877         } else {
 878             return null;
 879         }
 880     }
 881
 882     /**
 883      * Builds a tree of files This function is
 884      * then called recursively.
 885      *
 886      * @param $fileinfo an object returned by file_browser::get_file_info()
 887      * @param $search searched string
 888      * @param $dynamicmode bool no recursive call is done when in dynamic mode
 889      * @param $list - the array containing the files under the passed $fileinfo
 890      * @returns int the number of files found
 891      *
 892      * todo: take $search into account, and respect a threshold for dynamic loading
 893      */
 894     public static function build_tree($fileinfo, $search, $dynamicmode, &$list) {
 895         global $CFG, $OUTPUT;
 896
 897         $filecount = 0;
 898         $children = $fileinfo->get_children();
 899
 900         foreach ($children as $child) {
 901             $filename = $child->get_visible_name();
 902             $filesize = $child->get_filesize();
 903             $filesize = $filesize ? display_size($filesize) : '';
 904             $filedate = $child->get_timemodified();
 905             $filedate = $filedate ? userdate($filedate) : '';
 906             $filetype = $child->get_mimetype();
 907
 908             if ($child->is_directory()) {
 909                 $path = array();
 910                 $level = $child->get_parent();
 911                 while ($level) {
 912                     $params = $level->get_params();
 913                     $path[] = array($params['filepath'], $level->get_visible_name());
 914                     $level = $level->get_parent();
 915                 }
 916
 917                 $tmp = array(
 918                     'title' => $child->get_visible_name(),
 919                     'size' => 0,
 920                     'date' => $filedate,
 921                     'path' => array_reverse($path),
 922                     'thumbnail' => $OUTPUT->pix_url('f/folder-32')
 923                 );
 924
 925                 //if ($dynamicmode && $child->is_writable()) {
 926                 //    $tmp['children'] = array();
 927                 //} else {
 928                     // if folder name matches search, we send back all files contained.
 929                 $_search = $search;
 930                 if ($search && stristr($tmp['title'], $search) !== false) {
 931                     $_search = false;
 932                 }
 933                 $tmp['children'] = array();
 934                 $_filecount = repository::build_tree($child, $_search, $dynamicmode, $tmp['children']);
 935                 if ($search && $_filecount) {
 936                     $tmp['expanded'] = 1;
 937                 }
 938
 939                 //}
 940
 941                 if (!$search || $_filecount || (stristr($tmp['title'], $search) !== false)) {
 942                     $filecount += $_filecount;
 943                     $list[] = $tmp;
 944                 }
 945
 946             } else { // not a directory
 947                 // skip the file, if we're in search mode and it's not a match
 948                 if ($search && (stristr($filename, $search) === false)) {
 949                     continue;
 950                 }
 951                 $params = $child->get_params();
 952                 $source = serialize(array($params['contextid'], $params['component'], $params['filearea'], $params['itemid'], $params['filepath'], $params['filename']));
 953                 $list[] = array(
 954                     'title' => $filename,
 955                     'size' => $filesize,
 956                     'date' => $filedate,
 957                     //'source' => $child->get_url(),
 958                     'source' => base64_encode($source),
 959                     'thumbnail'=>$OUTPUT->pix_url(file_extension_icon($filename, 32)),
 960                 );
 961                 $filecount++;
 962             }
 963         }
 964
 965         return $filecount;
 966     }
 967
 968
 969     /**
 970      * Display a repository instance list (with edit/delete/create links)
 971      * @global object $CFG
 972      * @global object $USER
 973      * @global object $OUTPUT
 974      * @param object $context the context for which we display the instance
 975      * @param string $typename if set, we display only one type of instance
 976      */
 977     public static function display_instances_list($context, $typename = null) {
 978         global $CFG, $USER, $OUTPUT;
 979
 980         $output = $OUTPUT->box_start('generalbox');
 981         //if the context is SYSTEM, so we call it from administration page
 982         $admin = ($context->id == SYSCONTEXTID) ? true : false;
 983         if ($admin) {
 984             $baseurl = new moodle_url('/'.$CFG->admin.'/repositoryinstance.php', array('sesskey'=>sesskey()));
 985             $output .= $OUTPUT->heading(get_string('siteinstances', 'repository'));
 986         } else {
 987             $baseurl = new moodle_url('/repository/manage_instances.php', array('contextid'=>$context->id, 'sesskey'=>sesskey()));
 988         }
 989         $url = $baseurl;
 990
 991         $namestr = get_string('name');
 992         $pluginstr = get_string('plugin', 'repository');
 993         $settingsstr = get_string('settings');
 994         $deletestr = get_string('delete');
 995         //retrieve list of instances. In administration context we want to display all
 996         //instances of a type, even if this type is not visible. In course/user context we
 997         //want to display only visible instances, but for every type types. The repository::get_instances()
 998         //third parameter displays only visible type.
 999         $params = array();
1000         $params['context'] = array($context, get_system_context());
1001         $params['currentcontext'] = $context;
1002         $params['onlyvisible'] = !$admin;
1003         $params['type']        = $typename;
1004         $instances = repository::get_instances($params);
1005         $instancesnumber = count($instances);
1006         $alreadyplugins = array();
1007
1008         $table = new html_table();
1009         $table->head = array($namestr, $pluginstr, $settingsstr, $deletestr);
1010         $table->align = array('left', 'left', 'center','center');
1011         $table->data = array();
1012
1013         $updowncount = 1;
1014
1015         foreach ($instances as $i) {
1016             $settings = '';
1017             $delete = '';
1018
1019             $type = repository::get_type_by_id($i->options['typeid']);
1020
1021             if ($type->get_contextvisibility($context)) {
1022                 if (!$i->readonly) {
1023
1024                     $url->param('type', $i->options['type']);
1025                     $url->param('edit', $i->id);
1026                     $settings .= html_writer::link($url, $settingsstr);
1027
1028                     $url->remove_params('edit');
1029                     $url->param('delete', $i->id);
1030                     $delete .= html_writer::link($url, $deletestr);
1031
1032                     $url->remove_params('type');
1033                 }
1034             }
1035
1036             $type = repository::get_type_by_id($i->options['typeid']);
1037             $table->data[] = array($i->name, $type->get_readablename(), $settings, $delete);
1038
1039             //display a grey row if the type is defined as not visible
1040             if (isset($type) && !$type->get_visible()) {
1041                 $table->rowclasses[] = 'dimmed_text';
1042             } else {
1043                 $table->rowclasses[] = '';
1044             }
1045
1046             if (!in_array($i->name, $alreadyplugins)) {
1047                 $alreadyplugins[] = $i->name;
1048             }
1049         }
1050         $output .= html_writer::table($table);
1051         $instancehtml = '<div>';
1052         $addable = 0;
1053
1054         //if no type is set, we can create all type of instance
1055         if (!$typename) {
1056             $instancehtml .= '<h3>';
1057             $instancehtml .= get_string('createrepository', 'repository');
1058             $instancehtml .= '</h3><ul>';
1059             $types = repository::get_editable_types($context);
1060             foreach ($types as $type) {
1061                 if (!empty($type) && $type->get_visible()) {
1062                     $instanceoptionnames = repository::static_function($type->get_typename(), 'get_instance_option_names');
1063                     if (!empty($instanceoptionnames)) {
1064                         $baseurl->param('new', $type->get_typename());
1065                         $instancehtml .= '<li><a href="'.$baseurl->out().'">'.get_string('createxxinstance', 'repository', get_string('pluginname', 'repository_'.$type->get_typename())).  '</a></li>';
1066                         $baseurl->remove_params('new');
1067                         $addable++;
1068                     }
1069                 }
1070             }
1071             $instancehtml .= '</ul>';
1072
1073         } else {
1074             $instanceoptionnames = repository::static_function($typename, 'get_instance_option_names');
1075             if (!empty($instanceoptionnames)) {   //create a unique type of instance
1076                 $addable = 1;
1077                 $baseurl->param('new', $typename);
1078                 $instancehtml .= "<form action='".$baseurl->out()."' method='post'>
1079                     <p><input type='submit' value='".get_string('createinstance', 'repository')."'/></p>
1080                     </form>";
1081                 $baseurl->remove_params('new');
1082             }
1083         }
1084
1085         if ($addable) {
1086             $instancehtml .= '</div>';
1087             $output .= $instancehtml;
1088         }
1089
1090         $output .= $OUTPUT->box_end();
1091
1092         //print the list + creation links
1093         print($output);
1094     }
1095
1096     /**
1097      * Decide where to save the file, can be overwriten by subclass
1098      * @param string filename
1099      */
1100     public function prepare_file($filename) {
1101         global $CFG;
1102         if (!file_exists($CFG->dataroot.'/temp/download')) {
1103             mkdir($CFG->dataroot.'/temp/download/', $CFG->directorypermissions, true);
1104         }
1105         if (is_dir($CFG->dataroot.'/temp/download')) {
1106             $dir = $CFG->dataroot.'/temp/download/';
1107         }
1108         if (empty($filename)) {
1109             $filename = uniqid('repo').'_'.time().'.tmp';
1110         }
1111         if (file_exists($dir.$filename)) {
1112             $filename = uniqid('m').$filename;
1113         }
1114         return $dir.$filename;
1115     }
1116
1117     /**
1118      * Return file URL, for most plugins, the parameter is the original
1119      * url, but some plugins use a file id, so we need this function to
1120      * convert file id to original url.
1121      *
1122      * @param string $url the url of file
1123      * @return string
1124      */
1125     public function get_link($url) {
1126         return $url;
1127     }
1128
1129     /**
1130      * Download a file, this function can be overridden by
1131      * subclass.
1132      *
1133      * @global object $CFG
1134      * @param string $url the url of file
1135      * @param string $filename save location
1136      * @return string the location of the file
1137      * @see curl package
1138      */
1139     public function get_file($url, $filename = '') {
1140         global $CFG;
1141         $path = $this->prepare_file($filename);
1142         $fp = fopen($path, 'w');
1143         $c = new curl;
1144         $c->download(array(array('url'=>$url, 'file'=>$fp)));
1145         return array('path'=>$path, 'url'=>$url);
1146     }
1147
1148     /**
1149      * Return is the instance is visible
1150      * (is the type visible ? is the context enable ?)
1151      * @return boolean
1152      */
1153     public function is_visible() {
1154         $type = repository::get_type_by_id($this->options['typeid']);
1155         $instanceoptions = repository::static_function($type->get_typename(), 'get_instance_option_names');
1156
1157         if ($type->get_visible()) {
1158             //if the instance is unique so it's visible, otherwise check if the instance has a enabled context
1159             if (empty($instanceoptions) || $type->get_contextvisibility($this->context)) {
1160                 return true;
1161             }
1162         }
1163
1164         return false;
1165     }
1166
1167     /**
1168      * Return the name of this instance, can be overridden.
1169      * @global object $DB
1170      * @return string
1171      */
1172     public function get_name() {
1173         global $DB;
1174         if ( $name = $this->instance->name ) {
1175             return $name;
1176         } else {
1177             return get_string('pluginname', 'repository_' . $this->options['type']);
1178         }
1179     }
1180
1181     /**
1182      * what kind of files will be in this repository?
1183      * @return array return '*' means this repository support any files, otherwise
1184      *               return mimetypes of files, it can be an array
1185      */
1186     public function supported_filetypes() {
1187         // return array('text/plain', 'image/gif');
1188         return '*';
1189     }
1190
1191     /**
1192      * does it return a file url or a item_id
1193      * @return string
1194      */
1195     public function supported_returntypes() {
1196         return (FILE_INTERNAL | FILE_EXTERNAL);
1197     }
1198
1199     /**
1200      * Provide repository instance information for Ajax
1201      * @global object $CFG
1202      * @return object
1203      */
1204     final public function get_meta() {
1205         global $CFG, $OUTPUT;
1206         $ft = new filetype_parser;
1207         $meta = new stdClass();
1208         $meta->id   = $this->id;
1209         $meta->name = $this->get_name();
1210         $meta->type = $this->options['type'];
1211         $meta->icon = $OUTPUT->pix_url('icon', 'repository_'.$meta->type)->out(false);
1212         $meta->supported_types = $ft->get_extensions($this->supported_filetypes());
1213         $meta->return_types = $this->supported_returntypes();
1214         return $meta;
1215     }
1216
1217     /**
1218      * Create an instance for this plug-in
1219      * @global object $CFG
1220      * @global object $DB
1221      * @param string $type the type of the repository
1222      * @param integer $userid the user id
1223      * @param object $context the context
1224      * @param array $params the options for this instance
1225      * @param integer $readonly whether to create it readonly or not (defaults to not)
1226      * @return mixed
1227      */
1228     public static function create($type, $userid, $context, $params, $readonly=0) {
1229         global $CFG, $DB;
1230         $params = (array)$params;
1231         require_once($CFG->dirroot . '/repository/'. $type . '/lib.php');
1232         $classname = 'repository_' . $type;
1233         if ($repo = $DB->get_record('repository', array('type'=>$type))) {
1234             $record = new stdClass();
1235             $record->name = $params['name'];
1236             $record->typeid = $repo->id;
1237             $record->timecreated  = time();
1238             $record->timemodified = time();
1239             $record->contextid = $context->id;
1240             $record->readonly = $readonly;
1241             $record->userid    = $userid;
1242             $id = $DB->insert_record('repository_instances', $record);
1243             $options = array();
1244             $configs = call_user_func($classname . '::get_instance_option_names');
1245             if (!empty($configs)) {
1246                 foreach ($configs as $config) {
1247                     $options[$config] = $params[$config];
1248                 }
1249             }
1250
1251             if (!empty($id)) {
1252                 unset($options['name']);
1253                 $instance = repository::get_instance($id);
1254                 $instance->set_option($options);
1255                 return $id;
1256             } else {
1257                 return null;
1258             }
1259         } else {
1260             return null;
1261         }
1262     }
1263
1264     /**
1265      * delete a repository instance
1266      * @global object $DB
1267      * @return mixed
1268      */
1269     final public function delete() {
1270         global $DB;
1271         $DB->delete_records('repository_instances', array('id'=>$this->id));
1272         $DB->delete_records('repository_instance_config', array('instanceid'=>$this->id));
1273         return true;
1274     }
1275
1276     /**
1277      * Hide/Show a repository
1278      * @global object $DB
1279      * @param string $hide
1280      * @return boolean
1281      */
1282     final public function hide($hide = 'toggle') {
1283         global $DB;
1284         if ($entry = $DB->get_record('repository', array('id'=>$this->id))) {
1285             if ($hide === 'toggle' ) {
1286                 if (!empty($entry->visible)) {
1287                     $entry->visible = 0;
1288                 } else {
1289                     $entry->visible = 1;
1290                 }
1291             } else {
1292                 if (!empty($hide)) {
1293                     $entry->visible = 0;
1294                 } else {
1295                     $entry->visible = 1;
1296                 }
1297             }
1298             return $DB->update_record('repository', $entry);
1299         }
1300         return false;
1301     }
1302
1303     /**
1304      * Save settings for repository instance
1305      * $repo->set_option(array('api_key'=>'f2188bde132', 'name'=>'dongsheng'));
1306      * @global object $DB
1307      * @param array $options settings
1308      * @return int Id of the record
1309      */
1310     public function set_option($options = array()) {
1311         global $DB;
1312
1313         if (!empty($options['name'])) {
1314             $r = new stdClass();
1315             $r->id   = $this->id;
1316             $r->name = $options['name'];
1317             $DB->update_record('repository_instances', $r);
1318             unset($options['name']);
1319         }
1320         foreach ($options as $name=>$value) {
1321             if ($id = $DB->get_field('repository_instance_config', 'id', array('name'=>$name, 'instanceid'=>$this->id))) {
1322                 $DB->set_field('repository_instance_config', 'value', $value, array('id'=>$id));
1323             } else {
1324                 $config = new stdClass();
1325                 $config->instanceid = $this->id;
1326                 $config->name   = $name;
1327                 $config->value  = $value;
1328                 $DB->insert_record('repository_instance_config', $config);
1329             }
1330         }
1331         return true;
1332     }
1333
1334     /**
1335      * Get settings for repository instance
1336      * @global object $DB
1337      * @param string $config
1338      * @return array Settings
1339      */
1340     public function get_option($config = '') {
1341         global $DB;
1342         $entries = $DB->get_records('repository_instance_config', array('instanceid'=>$this->id));
1343         $ret = array();
1344         if (empty($entries)) {
1345             return $ret;
1346         }
1347         foreach($entries as $entry) {
1348             $ret[$entry->name] = $entry->value;
1349         }
1350         if (!empty($config)) {
1351             if (isset($ret[$config])) {
1352                 return $ret[$config];
1353             } else {
1354                 return null;
1355             }
1356         } else {
1357             return $ret;
1358         }
1359     }
1360
1361     public function filter(&$value) {
1362         $pass = false;
1363         $accepted_types = optional_param('accepted_types', '', PARAM_RAW);
1364         $ft = new filetype_parser;
1365         //$ext = $ft->get_extensions($this->supported_filetypes());
1366         if (isset($value['children'])) {
1367             $pass = true;
1368             if (!empty($value['children'])) {
1369                 $value['children'] = array_filter($value['children'], array($this, 'filter'));
1370             }
1371         } else {
1372             if ($accepted_types == '*' or empty($accepted_types)
1373                 or (is_array($accepted_types) and in_array('*', $accepted_types))) {
1374                 $pass = true;
1375             } elseif (is_array($accepted_types)) {
1376                 foreach ($accepted_types as $type) {
1377                     $extensions = $ft->get_extensions($type);
1378                     if (!is_array($extensions)) {
1379                         $pass = true;
1380                     } else {
1381                         foreach ($extensions as $ext) {
1382                             if (preg_match('#'.$ext.'$#', $value['title'])) {
1383                                 $pass = true;
1384                             }
1385                         }
1386                     }
1387                 }
1388             }
1389         }
1390         return $pass;
1391     }
1392
1393     /**
1394      * Given a path, and perhaps a search, get a list of files.
1395      *
1396      * See details on http://docs.moodle.org/en/Development:Repository_plugins
1397      *
1398      * @param string $path, this parameter can
1399      * a folder name, or a identification of folder
1400      * @param string $page, the page number of file list
1401      * @return array the list of files, including meta infomation, containing the following keys
1402      *           manage, url to manage url
1403      *           client_id
1404      *           login, login form
1405      *           repo_id, active repository id
1406      *           login_btn_action, the login button action
1407      *           login_btn_label, the login button label
1408      *           total, number of results
1409      *           perpage, items per page
1410      *           page
1411      *           pages, total pages
1412      *           issearchresult, is it a search result?
1413      *           list, file list
1414      *           path, current path and parent path
1415      */
1416     public function get_listing($path = '', $page = '') {
1417     }
1418
1419     /**
1420      * Search files in repository
1421      * When doing global search, $search_text will be used as
1422      * keyword.
1423      *
1424      * @return mixed, see get_listing()
1425      */
1426     public function search($search_text) {
1427         $list = array();
1428         $list['list'] = array();
1429         return false;
1430     }
1431
1432     /**
1433      * Logout from repository instance
1434      * By default, this function will return a login form
1435      *
1436      * @return string
1437      */
1438     public function logout(){
1439         return $this->print_login();
1440     }
1441
1442     /**
1443      * To check whether the user is logged in.
1444      *
1445      * @return boolean
1446      */
1447     public function check_login(){
1448         return true;
1449     }
1450
1451
1452     /**
1453      * Show the login screen, if required
1454      */
1455     public function print_login(){
1456         return $this->get_listing();
1457     }
1458
1459     /**
1460      * Show the search screen, if required
1461      * @return null
1462      */
1463     public function print_search() {
1464         $str = '';
1465         $str .= '<input type="hidden" name="repo_id" value="'.$this->id.'" />';
1466         $str .= '<input type="hidden" name="ctx_id" value="'.$this->context->id.'" />';
1467         $str .= '<input type="hidden" name="seekey" value="'.sesskey().'" />';
1468         $str .= '<label>'.get_string('keyword', 'repository').': </label><br/><input name="s" value="" /><br/>';
1469         return $str;
1470     }
1471
1472     /**
1473      * For oauth like external authentication, when external repository direct user back to moodle,
1474      * this funciton will be called to set up token and token_secret
1475      */
1476     public function callback() {
1477     }
1478
1479     /**
1480      * is it possible to do glboal search?
1481      * @return boolean
1482      */
1483     public function global_search() {
1484         return false;
1485     }
1486
1487     /**
1488      * Defines operations that happen occasionally on cron
1489      * @return boolean
1490      */
1491     public function cron() {
1492         return true;
1493     }
1494
1495     /**
1496      * function which is run when the type is created (moodle administrator add the plugin)
1497      * @return boolean success or fail?
1498      */
1499     public static function plugin_init() {
1500         return true;
1501     }
1502
1503     /**
1504      * Edit/Create Admin Settings Moodle form
1505      * @param object $mform Moodle form (passed by reference)
1506      * @param string $classname repository class name
1507      */
1508     public function type_config_form($mform, $classname = 'repository') {
1509         $instnaceoptions = call_user_func(array($classname, 'get_instance_option_names'), $mform, $classname);
1510         if (empty($instnaceoptions)) {
1511             // this plugin has only one instance
1512             // so we need to give it a name
1513             // it can be empty, then moodle will look for instance name from language string
1514             $mform->addElement('text', 'pluginname', get_string('pluginname', 'repository'), array('size' => '40'));
1515             $mform->addElement('static', 'pluginnamehelp', '', get_string('pluginnamehelp', 'repository'));
1516         }
1517     }
1518
1519     /**
1520      * Edit/Create Instance Settings Moodle form
1521      * @param object $mform Moodle form (passed by reference)
1522      */
1523     public function instance_config_form($mform) {
1524     }
1525
1526     /**
1527      * Return names of the general options
1528      * By default: no general option name
1529      * @return array
1530      */
1531     public static function get_type_option_names() {
1532         return array('pluginname');
1533     }
1534
1535     /**
1536      * Return names of the instance options
1537      * By default: no instance option name
1538      * @return array
1539      */
1540     public static function get_instance_option_names() {
1541         return array();
1542     }
1543
1544     public static function instance_form_validation($mform, $data, $errors) {
1545         return $errors;
1546     }
1547
1548     public function get_short_filename($str, $maxlength) {
1549         if (strlen($str) >= $maxlength) {
1550             return trim(substr($str, 0, $maxlength)).'...';
1551         } else {
1552             return $str;
1553         }
1554     }
1555 }
1556
1557 /**
1558  * Exception class for repository api
1559  *
1560  * @since 2.0
1561  * @package moodlecore
1562  * @subpackage repository
1563  * @copyright 2009 Dongsheng Cai <dongsheng@moodle.com>
1564  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1565  */
1566 class repository_exception extends moodle_exception {
1567 }
1568
1569 /**
1570  * This is a class used to define a repository instance form
1571  *
1572  * @since 2.0
1573  * @package moodlecore
1574  * @subpackage repository
1575  * @copyright 2009 Dongsheng Cai <dongsheng@moodle.com>
1576  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1577  */
1578 final class repository_instance_form extends moodleform {
1579     protected $instance;
1580     protected $plugin;
1581     protected function add_defaults() {
1582         $mform =& $this->_form;
1583         $strrequired = get_string('required');
1584
1585         $mform->addElement('hidden', 'edit',  ($this->instance) ? $this->instance->id : 0);
1586         $mform->setType('edit', PARAM_INT);
1587         $mform->addElement('hidden', 'new',   $this->plugin);
1588         $mform->setType('new', PARAM_FORMAT);
1589         $mform->addElement('hidden', 'plugin', $this->plugin);
1590         $mform->setType('plugin', PARAM_SAFEDIR);
1591         $mform->addElement('hidden', 'typeid', $this->typeid);
1592         $mform->setType('typeid', PARAM_INT);
1593         $mform->addElement('hidden', 'contextid', $this->contextid);
1594         $mform->setType('contextid', PARAM_INT);
1595
1596         $mform->addElement('text', 'name', get_string('name'), 'maxlength="100" size="30"');
1597         $mform->addRule('name', $strrequired, 'required', null, 'client');
1598     }
1599
1600     public function definition() {
1601         global $CFG;
1602         // type of plugin, string
1603         $this->plugin = $this->_customdata['plugin'];
1604         $this->typeid = $this->_customdata['typeid'];
1605         $this->contextid = $this->_customdata['contextid'];
1606         $this->instance = (isset($this->_customdata['instance'])
1607                 && is_subclass_of($this->_customdata['instance'], 'repository'))
1608             ? $this->_customdata['instance'] : null;
1609
1610         $mform =& $this->_form;
1611
1612         $this->add_defaults();
1613         //add fields
1614         if (!$this->instance) {
1615             $result = repository::static_function($this->plugin, 'instance_config_form', $mform);
1616             if ($result === false) {
1617                 $mform->removeElement('name');
1618             }
1619         } else {
1620             $data = array();
1621             $data['name'] = $this->instance->name;
1622             if (!$this->instance->readonly) {
1623                 $result = $this->instance->instance_config_form($mform);
1624                 if ($result === false) {
1625                     $mform->removeElement('name');
1626                 }
1627                 // and set the data if we have some.
1628                 foreach ($this->instance->get_instance_option_names() as $config) {
1629                     if (!empty($this->instance->options[$config])) {
1630                         $data[$config] = $this->instance->options[$config];
1631                      } else {
1632                         $data[$config] = '';
1633                      }
1634                 }
1635             }
1636             $this->set_data($data);
1637         }
1638
1639         if ($result === false) {
1640             $mform->addElement('cancel');
1641         } else {
1642             $this->add_action_buttons(true, get_string('save','repository'));
1643         }
1644     }
1645
1646     public function validation($data) {
1647         global $DB;
1648         $errors = array();
1649         $plugin = $this->_customdata['plugin'];
1650         $instance = (isset($this->_customdata['instance'])
1651                 && is_subclass_of($this->_customdata['instance'], 'repository'))
1652             ? $this->_customdata['instance'] : null;
1653         if (!$instance) {
1654             $errors = repository::static_function($plugin, 'instance_form_validation', $this, $data, $errors);
1655         } else {
1656             $errors = $instance->instance_form_validation($this, $data, $errors);
1657         }
1658
1659         $sql = "SELECT count('x')
1660                   FROM {repository_instances} i, {repository} r
1661                  WHERE r.type=:plugin AND r.id=i.typeid AND i.name=:name";
1662         if ($DB->count_records_sql($sql, array('name' => $data['name'], 'plugin' => $data['plugin'])) > 1) {
1663             $errors['name'] = get_string('erroruniquename', 'repository');
1664         }
1665
1666         return $errors;
1667     }
1668 }
1669
1670 /**
1671  * This is a class used to define a repository type setting form
1672  *
1673  * @since 2.0
1674  * @package moodlecore
1675  * @subpackage repository
1676  * @copyright 2009 Dongsheng Cai <dongsheng@moodle.com>
1677  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1678  */
1679 final class repository_type_form extends moodleform {
1680     protected $instance;
1681     protected $plugin;
1682     protected $action;
1683
1684     /**
1685      * Definition of the moodleform
1686      * @global object $CFG
1687      */
1688     public function definition() {
1689         global $CFG;
1690         // type of plugin, string
1691         $this->plugin = $this->_customdata['plugin'];
1692         $this->instance = (isset($this->_customdata['instance'])
1693                 && is_a($this->_customdata['instance'], 'repository_type'))
1694             ? $this->_customdata['instance'] : null;
1695
1696         $this->action = $this->_customdata['action'];
1697         $this->pluginname = $this->_customdata['pluginname'];
1698         $mform =& $this->_form;
1699         $strrequired = get_string('required');
1700
1701         $mform->addElement('hidden', 'action', $this->action);
1702         $mform->setType('action', PARAM_TEXT);
1703         $mform->addElement('hidden', 'repos', $this->plugin);
1704         $mform->setType('repos', PARAM_SAFEDIR);
1705
1706         // let the plugin add its specific fields
1707         $classname = 'repository_' . $this->plugin;
1708         require_once($CFG->dirroot . '/repository/' . $this->plugin . '/lib.php');
1709         //add "enable course/user instances" checkboxes if multiple instances are allowed
1710         $instanceoptionnames = repository::static_function($this->plugin, 'get_instance_option_names');
1711
1712         $result = call_user_func(array($classname, 'type_config_form'), $mform, $classname);
1713
1714         if (!empty($instanceoptionnames)) {
1715             $sm = get_string_manager();
1716             $component = 'repository';
1717             if ($sm->string_exists('enablecourseinstances', 'repository_' . $this->plugin)) {
1718                 $component .= ('_' . $this->plugin);
1719             }
1720             $mform->addElement('checkbox', 'enablecourseinstances', get_string('enablecourseinstances', $component));
1721
1722             $component = 'repository';
1723             if ($sm->string_exists('enableuserinstances', 'repository_' . $this->plugin)) {
1724                 $component .= ('_' . $this->plugin);
1725             }
1726             $mform->addElement('checkbox', 'enableuserinstances', get_string('enableuserinstances', $component));
1727         }
1728
1729         // set the data if we have some.
1730         if ($this->instance) {
1731             $data = array();
1732             $option_names = call_user_func(array($classname,'get_type_option_names'));
1733             if (!empty($instanceoptionnames)){
1734                 $option_names[] = 'enablecourseinstances';
1735                 $option_names[] = 'enableuserinstances';
1736             }
1737
1738             $instanceoptions = $this->instance->get_options();
1739             foreach ($option_names as $config) {
1740                 if (!empty($instanceoptions[$config])) {
1741                     $data[$config] = $instanceoptions[$config];
1742                 } else {
1743                     $data[$config] = '';
1744                 }
1745             }
1746             // XXX: set plugin name for plugins which doesn't have muliti instances
1747             if (empty($instanceoptionnames)){
1748                 $data['pluginname'] = $this->pluginname;
1749             }
1750             $this->set_data($data);
1751         }
1752
1753         $this->add_action_buttons(true, get_string('save','repository'));
1754     }
1755 }
1756
1757 /**
1758  * Generate all options needed by filepicker
1759  *
1760  * @param array $args, including following keys
1761  *          context
1762  *          accepted_types
1763  *          return_types
1764  *
1765  * @return array the list of repository instances, including meta infomation, containing the following keys
1766  *          externallink
1767  *          repositories
1768  *          accepted_types
1769  */
1770 function initialise_filepicker($args) {
1771     global $CFG, $USER, $PAGE, $OUTPUT;
1772     require_once($CFG->libdir . '/licenselib.php');
1773
1774     $return = new stdClass();
1775     $licenses = array();
1776     if (!empty($CFG->licenses)) {
1777         $array = explode(',', $CFG->licenses);
1778         foreach ($array as $license) {
1779             $l = new stdClass();
1780             $l->shortname = $license;
1781             $l->fullname = get_string($license, 'license');
1782             $licenses[] = $l;
1783         }
1784     }
1785     if (!empty($CFG->sitedefaultlicense)) {
1786         $return->defaultlicense = $CFG->sitedefaultlicense;
1787     }
1788
1789     $return->licenses = $licenses;
1790
1791     $return->author = fullname($USER);
1792
1793     $ft = new filetype_parser();
1794     if (empty($args->context)) {
1795         $context = $PAGE->context;
1796     } else {
1797         $context = $args->context;
1798     }
1799     $disable_types = array();
1800     if (!empty($args->disable_types)) {
1801         $disable_types = $args->disable_types;
1802     }
1803
1804     $user_context = get_context_instance(CONTEXT_USER, $USER->id);
1805
1806     list($context, $course, $cm) = get_context_info_array($context->id);
1807     $contexts = array($user_context, get_system_context());
1808     if (!empty($course)) {
1809         // adding course context
1810         $contexts[] = get_context_instance(CONTEXT_COURSE, $course->id);
1811     }
1812     $externallink = (int)get_config(null, 'repositoryallowexternallinks');
1813     $repositories = repository::get_instances(array(
1814         'context'=>$contexts,
1815         'currentcontext'=> $context,
1816         'accepted_types'=>$args->accepted_types,
1817         'return_types'=>$args->return_types,
1818         'disable_types'=>$disable_types
1819     ));
1820
1821     $return->repositories = array();
1822
1823     if (empty($externallink)) {
1824         $return->externallink = false;
1825     } else {
1826         $return->externallink = true;
1827     }
1828
1829     // provided by form element
1830     $return->accepted_types = $ft->get_extensions($args->accepted_types);
1831     $return->return_types = $args->return_types;
1832     foreach ($repositories as $repository) {
1833         $meta = $repository->get_meta();
1834         $return->repositories[$repository->id] = $meta;
1835     }
1836     return $return;
1837 }