lib/componentlib.class.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  * This library includes all the necessary stuff to use the one-click
  20  * download and install feature of Moodle, used to keep updated some
  21  * items like languages, pear, enviroment... i.e, components.
  22  *
  23  * It has been developed harcoding some important limits that are
  24  * explained below:
  25  *    - It only can check, download and install items under moodledata.
  26  *    - Every downloadeable item must be one zip file.
  27  *    - The zip file root content must be 1 directory, i.e, everything
  28  *      is stored under 1 directory.
  29  *    - Zip file name and root directory must have the same name (but
  30  *      the .zip extension, of course).
  31  *    - Every .zip file must be defined in one .md5 file that will be
  32  *      stored in the same remote directory than the .zip file.
  33  *    - The name of such .md5 file is free, although it's recommended
  34  *      to use the same name than the .zip (that's the default
  35  *      assumption if no specified).
  36  *    - Every remote .md5 file will be a comma separated (CVS) file where each
  37  *      line will follow this format:
  38  *        - Field 1: name of the zip file (without extension). Mandatory.
  39  *        - Field 2: md5 of the zip file. Mandatory.
  40  *        - Field 3: whatever you want (or need). Optional.
  41  *    -Every local .md5 file will:
  42  *        - Have the zip file name (without the extension) plus -md5
  43  *        - Will reside inside the expanded zip file dir
  44  *        - Will contain the md5 od the latest installed component
  45  * With all these details present, the process will perform this tasks:
  46  *    - Perform security checks. Only admins are allowed to use this for now.
  47  *    - Read the .md5 file from source (1).
  48  *    - Extract the correct line for the .zip being requested.
  49  *    - Compare it with the local .md5 file (2).
  50  *    - If different:
  51  *        - Download the newer .zip file from source.
  52  *        - Calculate its md5 (3).
  53  *        - Compare (1) and (3).
  54  *        - If equal:
  55  *            - Delete old directory.
  56  *            - Uunzip the newer .zip file.
  57  *            - Create the new local .md5 file.
  58  *            - Delete the .zip file.
  59  *        - If different:
  60  *            - ERROR. Old package won't be modified. We shouldn't
  61  *              reach here ever.
  62  *    - If component download is not possible, a message text about how to do
  63  *      the process manually (remotedownloaderror) must be displayed to explain it.
  64  *
  65  * General Usage:
  66  *
  67  * To install one component:
  68  * <code>
  69  *     require_once($CFG->libdir.'/componentlib.class.php');
  70  *     if ($cd = new component_installer('https://download.moodle.org', 'langpack/2.0',
  71  *                                       'es.zip', 'languages.md5', 'lang')) {
  72  *         $status = $cd->install(); //returns COMPONENT_(ERROR | UPTODATE | INSTALLED)
  73  *         switch ($status) {
  74  *             case COMPONENT_ERROR:
  75  *                 if ($cd->get_error() == 'remotedownloaderror') {
  76  *                     $a = new stdClass();
  77  *                     $a->url = 'https://download.moodle.org/langpack/2.0/es.zip';
  78  *                     $a->dest= $CFG->dataroot.'/lang';
  79  *                     print_error($cd->get_error(), 'error', '', $a);
  80  *                 } else {
  81  *                     print_error($cd->get_error(), 'error');
  82  *                 }
  83  *                 break;
  84  *             case COMPONENT_UPTODATE:
  85  *                 //Print error string or whatever you want to do
  86  *                 break;
  87  *             case COMPONENT_INSTALLED:
  88  *                 //Print/do whatever you want
  89  *                 break;
  90  *             default:
  91  *                 //We shouldn't reach this point
  92  *         }
  93  *     } else {
  94  *         //We shouldn't reach this point
  95  *     }
  96  * </code>
  97  *
  98  * To switch of component (maintaining the rest of settings):
  99  * <code>
 100  *     $status = $cd->change_zip_file('en.zip'); //returns boolean false on error
 101  * </code>
 102  *
 103  * To retrieve all the components in one remote md5 file
 104  * <code>
 105  *     $components = $cd->get_all_components_md5();  //returns boolean false on error, array instead
 106  * </code>
 107  *
 108  * To check if current component needs to be updated
 109  * <code>
 110  *     $status = $cd->need_upgrade();  //returns COMPONENT_(ERROR | UPTODATE | NEEDUPDATE)
 111  * </code>
 112  *
 113  * To get the 3rd field of the md5 file (optional)
 114  * <code>
 115  *     $field = $cd->get_extra_md5_field();  //returns string (empty if not exists)
 116  * </code>
 117  *
 118  * For all the error situations the $cd->get_error() method should return always the key of the
 119  * error to be retrieved by one standard get_string() call against the error.php lang file.
 120  *
 121  * That's all!
 122  *
 123  * @package   core
 124  * @copyright (C) 2001-3001 Eloy Lafuente (stronk7) {@link http://contiento.com}
 125  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 126  */
 127
 128 defined('MOODLE_INTERNAL') || die();
 129
 130  /**
 131   * @global object $CFG
 132   * @name $CFG
 133   */
 134 global $CFG;
 135 require_once($CFG->libdir.'/filelib.php');
 136
 137 // Some needed constants
 138 define('COMPONENT_ERROR',           0);
 139 define('COMPONENT_UPTODATE',        1);
 140 define('COMPONENT_NEEDUPDATE',      2);
 141 define('COMPONENT_INSTALLED',       3);
 142
 143 /**
 144  * This class is used to check, download and install items from
 145  * download.moodle.org to the moodledata directory.
 146  *
 147  * It always return true/false in all their public methods to say if
 148  * execution has ended succesfuly or not. If there is any problem
 149  * its getError() method can be called, returning one error string
 150  * to be used with the standard get/print_string() functions.
 151  *
 152  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 153  * @package moodlecore
 154  */
 155 class component_installer {
 156     /**
 157      * @var string
 158      */
 159     var $sourcebase;   /// Full http URL, base for downloadable items
 160     var $zippath;      /// Relative path (from sourcebase) where the
 161                        /// downloadeable item resides.
 162     var $zipfilename;  /// Name of the .zip file to be downloaded
 163     var $md5filename;  /// Name of the .md5 file to be read
 164     var $componentname;/// Name of the component. Must be the zip name without
 165                        /// the extension. And it defines a lot of things:
 166                        /// the md5 line to search for, the default m5 file name
 167                        /// and the name of the root dir stored inside the zip file
 168     var $destpath;     /// Relative path (from moodledata) where the .zip
 169                        /// file will be expanded.
 170     var $errorstring;  /// Latest error produced. It will contain one lang string key.
 171     var $extramd5info; /// Contents of the optional third field in the .md5 file.
 172     var $requisitesok; /// Flag to see if requisites check has been passed ok.
 173     /**
 174      * @var array
 175      */
 176     var $cachedmd5components; /// Array of cached components to avoid to
 177                               /// download the same md5 file more than once per request.
 178
 179     /**
 180      * Standard constructor of the class. It will initialize all attributes.
 181      * without performing any check at all.
 182      *
 183      * @param string $sourcebase Full http URL, base for downloadeable items
 184      * @param string $zippath Relative path (from sourcebase) where the
 185      *               downloadeable item resides
 186      * @param string $zipfilename Name of the .zip file to be downloaded
 187      * @param string $md5filename Name of the .md5 file to be read (default '' = same
 188      *               than zipfilename)
 189      * @param string $destpath Relative path (from moodledata) where the .zip file will
 190      *               be expanded (default='' = moodledataitself)
 191      * @return object
 192      */
 193     public function __construct($sourcebase, $zippath, $zipfilename, $md5filename='', $destpath='') {
 194
 195         $this->sourcebase   = $sourcebase;
 196         $this->zippath      = $zippath;
 197         $this->zipfilename  = $zipfilename;
 198         $this->md5filename  = $md5filename;
 199         $this->componentname= '';
 200         $this->destpath     = $destpath;
 201         $this->errorstring  = '';
 202         $this->extramd5info = '';
 203         $this->requisitesok = false;
 204         $this->cachedmd5components = array();
 205
 206         $this->check_requisites();
 207     }
 208
 209     /**
 210      * Old syntax of class constructor. Deprecated in PHP7.
 211      *
 212      * @deprecated since Moodle 3.1
 213      */
 214     public function component_installer($sourcebase, $zippath, $zipfilename, $md5filename='', $destpath='') {
 215         debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
 216         self::__construct($sourcebase, $zippath, $zipfilename, $md5filename, $destpath);
 217     }
 218
 219     /**
 220      * This function will check if everything is properly set to begin
 221      * one installation. Also, it will check for required settings
 222      * and will fill everything as needed.
 223      *
 224      * @global object
 225      * @return boolean true/false (plus detailed error in errorstring)
 226      */
 227     function check_requisites() {
 228         global $CFG;
 229
 230         $this->requisitesok = false;
 231
 232     /// Check that everything we need is present
 233         if (empty($this->sourcebase) || empty($this->zipfilename)) {
 234             $this->errorstring='missingrequiredfield';
 235             return false;
 236         }
 237     /// Check for correct sourcebase (this will be out in the future)
 238         if (!PHPUNIT_TEST and $this->sourcebase != 'https://download.moodle.org') {
 239             $this->errorstring='wrongsourcebase';
 240             return false;
 241         }
 242     /// Check the zip file is a correct one (by extension)
 243         if (stripos($this->zipfilename, '.zip') === false) {
 244             $this->errorstring='wrongzipfilename';
 245             return false;
 246         }
 247     /// Check that exists under dataroot
 248         if (!empty($this->destpath)) {
 249             if (!file_exists($CFG->dataroot.'/'.$this->destpath)) {
 250                 $this->errorstring='wrongdestpath';
 251                 return false;
 252             }
 253         }
 254     /// Calculate the componentname
 255         $pos = stripos($this->zipfilename, '.zip');
 256         $this->componentname = substr($this->zipfilename, 0, $pos);
 257     /// Calculate md5filename if it's empty
 258         if (empty($this->md5filename)) {
 259             $this->md5filename = $this->componentname.'.md5';
 260         }
 261     /// Set the requisites passed flag
 262         $this->requisitesok = true;
 263         return true;
 264     }
 265
 266     /**
 267      * This function will perform the full installation if needed, i.e.
 268      * compare md5 values, download, unzip, install and regenerate
 269      * local md5 file
 270      *
 271      * @uses COMPONENT_ERROR
 272      * @uses COMPONENT_UPTODATE
 273      * @uses COMPONENT_ERROR
 274      * @uses COMPONENT_INSTALLED
 275      * @return int COMPONENT_(ERROR | UPTODATE | INSTALLED)
 276      */
 277     public function install() {
 278         global $CFG;
 279
 280     /// Check requisites are passed
 281         if (!$this->requisitesok) {
 282             return COMPONENT_ERROR;
 283         }
 284     /// Confirm we need upgrade
 285         if ($this->need_upgrade() === COMPONENT_ERROR) {
 286             return COMPONENT_ERROR;
 287         } else if ($this->need_upgrade() === COMPONENT_UPTODATE) {
 288             $this->errorstring='componentisuptodate';
 289             return COMPONENT_UPTODATE;
 290         }
 291     /// Create temp directory if necesary
 292         if (!make_temp_directory('', false)) {
 293              $this->errorstring='cannotcreatetempdir';
 294              return COMPONENT_ERROR;
 295         }
 296     /// Download zip file and save it to temp
 297         if ($this->zippath) {
 298             $source = $this->sourcebase.'/'.$this->zippath.'/'.$this->zipfilename;
 299         } else {
 300             $source = $this->sourcebase.'/'.$this->zipfilename;
 301         }
 302
 303         $zipfile= $CFG->tempdir.'/'.$this->zipfilename;
 304
 305         if($contents = download_file_content($source)) {
 306             if ($file = fopen($zipfile, 'w')) {
 307                 if (!fwrite($file, $contents)) {
 308                     fclose($file);
 309                     $this->errorstring='cannotsavezipfile';
 310                     return COMPONENT_ERROR;
 311                 }
 312             } else {
 313                 $this->errorstring='cannotsavezipfile';
 314                 return COMPONENT_ERROR;
 315             }
 316             fclose($file);
 317         } else {
 318             $this->errorstring='cannotdownloadzipfile';
 319             return COMPONENT_ERROR;
 320         }
 321     /// Calculate its md5
 322         $new_md5 = md5($contents);
 323     /// Compare it with the remote md5 to check if we have the correct zip file
 324         if (!$remote_md5 = $this->get_component_md5()) {
 325             return COMPONENT_ERROR;
 326         }
 327         if ($new_md5 != $remote_md5) {
 328             $this->errorstring='downloadedfilecheckfailed';
 329             return COMPONENT_ERROR;
 330         }
 331
 332         // Move current revision to a safe place.
 333         $destinationdir = $CFG->dataroot . '/' . $this->destpath;
 334         $destinationcomponent = $destinationdir . '/' . $this->componentname;
 335         $destinationcomponentold = $destinationcomponent . '_old';
 336         @remove_dir($destinationcomponentold);     // Deleting a possible old version.
 337
 338         // Moving to a safe place.
 339         @rename($destinationcomponent, $destinationcomponentold);
 340
 341         // Unzip new version.
 342         $packer = get_file_packer('application/zip');
 343         $unzipsuccess = $packer->extract_to_pathname($zipfile, $destinationdir, null, null, true);
 344         if (!$unzipsuccess) {
 345             @remove_dir($destinationcomponent);
 346             @rename($destinationcomponentold, $destinationcomponent);
 347             $this->errorstring = 'cannotunzipfile';
 348             return COMPONENT_ERROR;
 349         }
 350
 351         // Delete old component version.
 352         @remove_dir($destinationcomponentold);
 353
 354         // Create local md5.
 355         if ($file = fopen($destinationcomponent.'/'.$this->componentname.'.md5', 'w')) {
 356             if (!fwrite($file, $new_md5)) {
 357                 fclose($file);
 358                 $this->errorstring='cannotsavemd5file';
 359                 return COMPONENT_ERROR;
 360             }
 361         } else  {
 362             $this->errorstring='cannotsavemd5file';
 363             return COMPONENT_ERROR;
 364         }
 365         fclose($file);
 366     /// Delete temp zip file
 367         @unlink($zipfile);
 368
 369         return COMPONENT_INSTALLED;
 370     }
 371
 372     /**
 373      * This function will detect if remote component needs to be installed
 374      * because it's different from the local one
 375      *
 376      * @uses COMPONENT_ERROR
 377      * @uses COMPONENT_UPTODATE
 378      * @uses COMPONENT_NEEDUPDATE
 379      * @return int COMPONENT_(ERROR | UPTODATE | NEEDUPDATE)
 380      */
 381     function need_upgrade() {
 382
 383     /// Check requisites are passed
 384         if (!$this->requisitesok) {
 385             return COMPONENT_ERROR;
 386         }
 387     /// Get local md5
 388         $local_md5 = $this->get_local_md5();
 389     /// Get remote md5
 390         if (!$remote_md5 = $this->get_component_md5()) {
 391             return COMPONENT_ERROR;
 392         }
 393     /// Return result
 394        if ($local_md5 == $remote_md5) {
 395            return COMPONENT_UPTODATE;
 396        } else {
 397            return COMPONENT_NEEDUPDATE;
 398        }
 399     }
 400
 401     /**
 402      * This function will change the zip file to install on the fly
 403      * to allow the class to process different components of the
 404      * same md5 file without intantiating more objects.
 405      *
 406      * @param string $newzipfilename New zip filename to process
 407      * @return boolean true/false
 408      */
 409     function change_zip_file($newzipfilename) {
 410
 411         $this->zipfilename = $newzipfilename;
 412         return $this->check_requisites();
 413     }
 414
 415     /**
 416      * This function will get the local md5 value of the installed
 417      * component.
 418      *
 419      * @global object
 420      * @return bool|string md5 of the local component (false on error)
 421      */
 422     function get_local_md5() {
 423         global $CFG;
 424
 425     /// Check requisites are passed
 426         if (!$this->requisitesok) {
 427             return false;
 428         }
 429
 430         $return_value = 'needtobeinstalled';   /// Fake value to force new installation
 431
 432     /// Calculate source to read
 433        $source = $CFG->dataroot.'/'.$this->destpath.'/'.$this->componentname.'/'.$this->componentname.'.md5';
 434     /// Read md5 value stored (if exists)
 435        if (file_exists($source)) {
 436            if ($temp = file_get_contents($source)) {
 437                $return_value = $temp;
 438            }
 439         }
 440         return $return_value;
 441     }
 442
 443     /**
 444      * This function will download the specified md5 file, looking for the
 445      * current componentname, returning its md5 field and storing extramd5info
 446      * if present. Also it caches results to cachedmd5components for better
 447      * performance in the same request.
 448      *
 449      * @return mixed md5 present in server (or false if error)
 450      */
 451     function get_component_md5() {
 452
 453     /// Check requisites are passed
 454         if (!$this->requisitesok) {
 455             return false;
 456         }
 457     /// Get all components of md5 file
 458         if (!$comp_arr = $this->get_all_components_md5()) {
 459             if (empty($this->errorstring)) {
 460                 $this->errorstring='cannotdownloadcomponents';
 461             }
 462             return false;
 463         }
 464     /// Search for the componentname component
 465         if (empty($comp_arr[$this->componentname]) || !$component = $comp_arr[$this->componentname]) {
 466              $this->errorstring='cannotfindcomponent';
 467              return false;
 468         }
 469     /// Check we have a valid md5
 470         if (empty($component[1]) || strlen($component[1]) != 32) {
 471             $this->errorstring='invalidmd5';
 472             return false;
 473         }
 474     /// Set the extramd5info field
 475         if (!empty($component[2])) {
 476             $this->extramd5info = $component[2];
 477         }
 478         return $component[1];
 479     }
 480
 481     /**
 482      * This function allows you to retrieve the complete array of components found in
 483      * the md5filename
 484      *
 485      * @return bool|array array of components in md5 file or false if error
 486      */
 487     function get_all_components_md5() {
 488
 489     /// Check requisites are passed
 490         if (!$this->requisitesok) {
 491             return false;
 492         }
 493
 494     /// Initialize components array
 495         $comp_arr = array();
 496
 497     /// Define and retrieve the full md5 file
 498         if ($this->zippath) {
 499             $source = $this->sourcebase.'/'.$this->zippath.'/'.$this->md5filename;
 500         } else {
 501             $source = $this->sourcebase.'/'.$this->md5filename;
 502         }
 503
 504     /// Check if we have downloaded the md5 file before (per request cache)
 505         if (!empty($this->cachedmd5components[$source])) {
 506             $comp_arr = $this->cachedmd5components[$source];
 507         } else {
 508         /// Not downloaded, let's do it now
 509             $availablecomponents = array();
 510
 511             if ($contents = download_file_content($source)) {
 512             /// Split text into lines
 513                 $lines=preg_split('/\r?\n/',$contents);
 514             /// Each line will be one component
 515                 foreach($lines as $line) {
 516                     $availablecomponents[] = explode(',', $line);
 517                 }
 518             /// If no components have been found, return error
 519                 if (empty($availablecomponents)) {
 520                     $this->errorstring='cannotdownloadcomponents';
 521                     return false;
 522                 }
 523             /// Build an associative array of components for easily search
 524             /// applying trim to avoid linefeeds and other...
 525                 $comp_arr = array();
 526                 foreach ($availablecomponents as $component) {
 527                 /// Avoid sometimes empty lines
 528                     if (empty($component[0])) {
 529                         continue;
 530                     }
 531                     $component[0]=trim($component[0]);
 532                     if (!empty($component[1])) {
 533                         $component[1]=trim($component[1]);
 534                     }
 535                     if (!empty($component[2])) {
 536                         $component[2]=trim($component[2]);
 537                     }
 538                     $comp_arr[$component[0]] = $component;
 539                 }
 540             /// Cache components
 541                 $this->cachedmd5components[$source] = $comp_arr;
 542             } else {
 543             /// Return error
 544                 $this->errorstring='remotedownloaderror';
 545                 return false;
 546             }
 547         }
 548     /// If there is no commponents or erros found, error
 549         if (!empty($this->errorstring)) {
 550              return false;
 551
 552         } else if (empty($comp_arr)) {
 553              $this->errorstring='cannotdownloadcomponents';
 554              return false;
 555         }
 556         return $comp_arr;
 557     }
 558
 559     /**
 560      * This function returns the errorstring
 561      *
 562      * @return string the error string
 563      */
 564     function get_error() {
 565         return $this->errorstring;
 566     }
 567
 568     /** This function returns the extramd5 field (optional in md5 file)
 569      *
 570      * @return string the extramd5 field
 571      */
 572     function get_extra_md5_field() {
 573         return $this->extramd5info;
 574     }
 575
 576 } /// End of component_installer class
 577
 578
 579 /**
 580  * Language packs installer
 581  *
 582  * This class wraps the functionality provided by {@link component_installer}
 583  * and adds support for installing a set of language packs.
 584  *
 585  * Given an array of required language packs, this class fetches them all
 586  * and installs them. It detects eventual dependencies and installs
 587  * all parent languages, too.
 588  *
 589  * @copyright 2011 David Mudrak <david@moodle.com>
 590  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 591  */
 592 class lang_installer {
 593
 594     /** lang pack was successfully downloaded and deployed */
 595     const RESULT_INSTALLED      = 'installed';
 596     /** lang pack was up-to-date so no download was needed */
 597     const RESULT_UPTODATE       = 'uptodate';
 598     /** there was a problem with downloading the lang pack */
 599     const RESULT_DOWNLOADERROR  = 'downloaderror';
 600
 601     /** @var array of languages to install */
 602     protected $queue = array();
 603     /** @var string the code of language being currently installed */
 604     protected $current;
 605     /** @var array of languages already installed by this instance */
 606     protected $done = array();
 607     /** @var string this Moodle major version */
 608     protected $version;
 609
 610     /**
 611      * Prepare the installer
 612      *
 613      * @param string|array $langcode a code of the language to install
 614      */
 615     public function __construct($langcode = '') {
 616         global $CFG;
 617
 618         $this->set_queue($langcode);
 619         $this->version = moodle_major_version(true);
 620
 621         if (!empty($CFG->langotherroot) and $CFG->langotherroot !== $CFG->dataroot . '/lang') {
 622             debugging('The in-built language pack installer does not support alternative location ' .
 623                 'of languages root directory. You are supposed to install and update your language '.
 624                 'packs on your own.');
 625         }
 626     }
 627
 628     /**
 629      * Sets the queue of language packs to be installed
 630      *
 631      * @param string|array $langcodes language code like 'cs' or a list of them
 632      */
 633     public function set_queue($langcodes) {
 634         if (is_array($langcodes)) {
 635             $this->queue = $langcodes;
 636         } else if (!empty($langcodes)) {
 637             $this->queue = array($langcodes);
 638         }
 639     }
 640
 641     /**
 642      * Runs the installer
 643      *
 644      * This method calls {@link self::install_language_pack} for every language in the
 645      * queue. If a dependency is detected, the parent language is added to the queue.
 646      *
 647      * @return array results, array of self::RESULT_xxx constants indexed by language code
 648      */
 649     public function run() {
 650
 651         $results = array();
 652
 653         while ($this->current = array_shift($this->queue)) {
 654
 655             if ($this->was_processed($this->current)) {
 656                 // do not repeat yourself
 657                 continue;
 658             }
 659
 660             if ($this->current === 'en') {
 661                 $this->mark_processed($this->current);
 662                 continue;
 663             }
 664
 665             $results[$this->current] = $this->install_language_pack($this->current);
 666
 667             if (in_array($results[$this->current], array(self::RESULT_INSTALLED, self::RESULT_UPTODATE))) {
 668                 if ($parentlang = $this->get_parent_language($this->current)) {
 669                     if (!$this->is_queued($parentlang) and !$this->was_processed($parentlang)) {
 670                         $this->add_to_queue($parentlang);
 671                     }
 672                 }
 673             }
 674
 675             $this->mark_processed($this->current);
 676         }
 677
 678         return $results;
 679     }
 680
 681     /**
 682      * Returns the URL where a given language pack can be downloaded
 683      *
 684      * Alternatively, if the parameter is empty, returns URL of the page with the
 685      * list of all available language packs.
 686      *
 687      * @param string $langcode language code like 'cs' or empty for unknown
 688      * @return string URL
 689      */
 690     public function lang_pack_url($langcode = '') {
 691
 692         if (empty($langcode)) {
 693             return 'https://download.moodle.org/langpack/'.$this->version.'/';
 694         } else {
 695             return 'https://download.moodle.org/download.php/langpack/'.$this->version.'/'.$langcode.'.zip';
 696         }
 697     }
 698
 699     /**
 700      * Returns the list of available language packs from download.moodle.org
 701      *
 702      * @return array|bool false if can not download
 703      */
 704     public function get_remote_list_of_languages() {
 705         $source = 'https://download.moodle.org/langpack/' . $this->version . '/languages.md5';
 706         $availablelangs = array();
 707
 708         if ($content = download_file_content($source)) {
 709             $alllines = explode("\n", $content);
 710             foreach($alllines as $line) {
 711                 if (!empty($line)){
 712                     $availablelangs[] = explode(',', $line);
 713                 }
 714             }
 715             return $availablelangs;
 716
 717         } else {
 718             return false;
 719         }
 720     }
 721
 722     // Internal implementation /////////////////////////////////////////////////
 723
 724     /**
 725      * Adds a language pack (or a list of them) to the queue
 726      *
 727      * @param string|array $langcodes code of the language to install or a list of them
 728      */
 729     protected function add_to_queue($langcodes) {
 730         if (is_array($langcodes)) {
 731             $this->queue = array_merge($this->queue, $langcodes);
 732         } else if (!empty($langcodes)) {
 733             $this->queue[] = $langcodes;
 734         }
 735     }
 736
 737     /**
 738      * Checks if the given language is queued or if the queue is empty
 739      *
 740      * @example $installer->is_queued('es');    // is Spanish going to be installed?
 741      * @example $installer->is_queued();        // is there a language queued?
 742      *
 743      * @param string $langcode language code or empty string for "any"
 744      * @return boolean
 745      */
 746     protected function is_queued($langcode = '') {
 747
 748         if (empty($langcode)) {
 749             return !empty($this->queue);
 750
 751         } else {
 752             return in_array($langcode, $this->queue);
 753         }
 754     }
 755
 756     /**
 757      * Checks if the given language has already been processed by this instance
 758      *
 759      * @see self::mark_processed()
 760      * @param string $langcode
 761      * @return boolean
 762      */
 763     protected function was_processed($langcode) {
 764         return isset($this->done[$langcode]);
 765     }
 766
 767     /**
 768      * Mark the given language pack as processed
 769      *
 770      * @see self::was_processed()
 771      * @param string $langcode
 772      */
 773     protected function mark_processed($langcode) {
 774         $this->done[$langcode] = 1;
 775     }
 776
 777     /**
 778      * Returns a parent language of the given installed language
 779      *
 780      * @param string $langcode
 781      * @return string parent language's code
 782      */
 783     protected function get_parent_language($langcode) {
 784         return get_parent_language($langcode);
 785     }
 786
 787     /**
 788      * Perform the actual language pack installation
 789      *
 790      * @uses component_installer
 791      * @param string $langcode
 792      * @return int return status
 793      */
 794     protected function install_language_pack($langcode) {
 795
 796         // initialise new component installer to process this language
 797         $installer = new component_installer('https://download.moodle.org', 'download.php/direct/langpack/' . $this->version,
 798             $langcode . '.zip', 'languages.md5', 'lang');
 799
 800         if (!$installer->requisitesok) {
 801             throw new lang_installer_exception('installer_requisites_check_failed');
 802         }
 803
 804         $status = $installer->install();
 805
 806         if ($status == COMPONENT_ERROR) {
 807             if ($installer->get_error() === 'remotedownloaderror') {
 808                 return self::RESULT_DOWNLOADERROR;
 809             } else {
 810                 throw new lang_installer_exception($installer->get_error(), $langcode);
 811             }
 812
 813         } else if ($status == COMPONENT_UPTODATE) {
 814             return self::RESULT_UPTODATE;
 815
 816         } else if ($status == COMPONENT_INSTALLED) {
 817             return self::RESULT_INSTALLED;
 818
 819         } else {
 820             throw new lang_installer_exception('unexpected_installer_result', $status);
 821         }
 822     }
 823 }
 824
 825
 826 /**
 827  * Exception thrown by {@link lang_installer}
 828  *
 829  * @copyright 2011 David Mudrak <david@moodle.com>
 830  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 831  */
 832 class lang_installer_exception extends moodle_exception {
 833
 834     public function __construct($errorcode, $debuginfo = null) {
 835         parent::__construct($errorcode, 'error', '', null, $debuginfo);
 836     }
 837 }