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      * @global object
 272      * @uses COMPONENT_ERROR
 273      * @uses COMPONENT_UPTODATE
 274      * @uses COMPONENT_ERROR
 275      * @uses COMPONENT_INSTALLED
 276      * @return int COMPONENT_(ERROR | UPTODATE | INSTALLED)
 277      */
 278     function install() {
 279
 280         global $CFG;
 281
 282     /// Check requisites are passed
 283         if (!$this->requisitesok) {
 284             return COMPONENT_ERROR;
 285         }
 286     /// Confirm we need upgrade
 287         if ($this->need_upgrade() === COMPONENT_ERROR) {
 288             return COMPONENT_ERROR;
 289         } else if ($this->need_upgrade() === COMPONENT_UPTODATE) {
 290             $this->errorstring='componentisuptodate';
 291             return COMPONENT_UPTODATE;
 292         }
 293     /// Create temp directory if necesary
 294         if (!make_temp_directory('', false)) {
 295              $this->errorstring='cannotcreatetempdir';
 296              return COMPONENT_ERROR;
 297         }
 298     /// Download zip file and save it to temp
 299         if ($this->zippath) {
 300             $source = $this->sourcebase.'/'.$this->zippath.'/'.$this->zipfilename;
 301         } else {
 302             $source = $this->sourcebase.'/'.$this->zipfilename;
 303         }
 304
 305         $zipfile= $CFG->tempdir.'/'.$this->zipfilename;
 306
 307         if($contents = download_file_content($source)) {
 308             if ($file = fopen($zipfile, 'w')) {
 309                 if (!fwrite($file, $contents)) {
 310                     fclose($file);
 311                     $this->errorstring='cannotsavezipfile';
 312                     return COMPONENT_ERROR;
 313                 }
 314             } else {
 315                 $this->errorstring='cannotsavezipfile';
 316                 return COMPONENT_ERROR;
 317             }
 318             fclose($file);
 319         } else {
 320             $this->errorstring='cannotdownloadzipfile';
 321             return COMPONENT_ERROR;
 322         }
 323     /// Calculate its md5
 324         $new_md5 = md5($contents);
 325     /// Compare it with the remote md5 to check if we have the correct zip file
 326         if (!$remote_md5 = $this->get_component_md5()) {
 327             return COMPONENT_ERROR;
 328         }
 329         if ($new_md5 != $remote_md5) {
 330             $this->errorstring='downloadedfilecheckfailed';
 331             return COMPONENT_ERROR;
 332         }
 333     /// Move current revision to a safe place
 334         $destinationdir = $CFG->dataroot.'/'.$this->destpath;
 335         $destinationcomponent = $destinationdir.'/'.$this->componentname;
 336         @remove_dir($destinationcomponent.'_old');     // Deleting a possible old version.
 337
 338         // Moving to a safe place.
 339         @rename($destinationcomponent, $destinationcomponent.'_old');
 340
 341     /// Unzip new version
 342         if (!unzip_file($zipfile, $destinationdir, false)) {
 343         /// Error so, go back to the older
 344             @remove_dir($destinationcomponent);
 345             @rename ($destinationcomponent.'_old', $destinationcomponent);
 346             $this->errorstring='cannotunzipfile';
 347             return COMPONENT_ERROR;
 348         }
 349     /// Delete old component version
 350         @remove_dir($destinationcomponent.'_old');
 351     /// Create local md5
 352         if ($file = fopen($destinationcomponent.'/'.$this->componentname.'.md5', 'w')) {
 353             if (!fwrite($file, $new_md5)) {
 354                 fclose($file);
 355                 $this->errorstring='cannotsavemd5file';
 356                 return COMPONENT_ERROR;
 357             }
 358         } else  {
 359             $this->errorstring='cannotsavemd5file';
 360             return COMPONENT_ERROR;
 361         }
 362         fclose($file);
 363     /// Delete temp zip file
 364         @unlink($zipfile);
 365
 366         return COMPONENT_INSTALLED;
 367     }
 368
 369     /**
 370      * This function will detect if remote component needs to be installed
 371      * because it's different from the local one
 372      *
 373      * @uses COMPONENT_ERROR
 374      * @uses COMPONENT_UPTODATE
 375      * @uses COMPONENT_NEEDUPDATE
 376      * @return int COMPONENT_(ERROR | UPTODATE | NEEDUPDATE)
 377      */
 378     function need_upgrade() {
 379
 380     /// Check requisites are passed
 381         if (!$this->requisitesok) {
 382             return COMPONENT_ERROR;
 383         }
 384     /// Get local md5
 385         $local_md5 = $this->get_local_md5();
 386     /// Get remote md5
 387         if (!$remote_md5 = $this->get_component_md5()) {
 388             return COMPONENT_ERROR;
 389         }
 390     /// Return result
 391        if ($local_md5 == $remote_md5) {
 392            return COMPONENT_UPTODATE;
 393        } else {
 394            return COMPONENT_NEEDUPDATE;
 395        }
 396     }
 397
 398     /**
 399      * This function will change the zip file to install on the fly
 400      * to allow the class to process different components of the
 401      * same md5 file without intantiating more objects.
 402      *
 403      * @param string $newzipfilename New zip filename to process
 404      * @return boolean true/false
 405      */
 406     function change_zip_file($newzipfilename) {
 407
 408         $this->zipfilename = $newzipfilename;
 409         return $this->check_requisites();
 410     }
 411
 412     /**
 413      * This function will get the local md5 value of the installed
 414      * component.
 415      *
 416      * @global object
 417      * @return bool|string md5 of the local component (false on error)
 418      */
 419     function get_local_md5() {
 420         global $CFG;
 421
 422     /// Check requisites are passed
 423         if (!$this->requisitesok) {
 424             return false;
 425         }
 426
 427         $return_value = 'needtobeinstalled';   /// Fake value to force new installation
 428
 429     /// Calculate source to read
 430        $source = $CFG->dataroot.'/'.$this->destpath.'/'.$this->componentname.'/'.$this->componentname.'.md5';
 431     /// Read md5 value stored (if exists)
 432        if (file_exists($source)) {
 433            if ($temp = file_get_contents($source)) {
 434                $return_value = $temp;
 435            }
 436         }
 437         return $return_value;
 438     }
 439
 440     /**
 441      * This function will download the specified md5 file, looking for the
 442      * current componentname, returning its md5 field and storing extramd5info
 443      * if present. Also it caches results to cachedmd5components for better
 444      * performance in the same request.
 445      *
 446      * @return mixed md5 present in server (or false if error)
 447      */
 448     function get_component_md5() {
 449
 450     /// Check requisites are passed
 451         if (!$this->requisitesok) {
 452             return false;
 453         }
 454     /// Get all components of md5 file
 455         if (!$comp_arr = $this->get_all_components_md5()) {
 456             if (empty($this->errorstring)) {
 457                 $this->errorstring='cannotdownloadcomponents';
 458             }
 459             return false;
 460         }
 461     /// Search for the componentname component
 462         if (empty($comp_arr[$this->componentname]) || !$component = $comp_arr[$this->componentname]) {
 463              $this->errorstring='cannotfindcomponent';
 464              return false;
 465         }
 466     /// Check we have a valid md5
 467         if (empty($component[1]) || strlen($component[1]) != 32) {
 468             $this->errorstring='invalidmd5';
 469             return false;
 470         }
 471     /// Set the extramd5info field
 472         if (!empty($component[2])) {
 473             $this->extramd5info = $component[2];
 474         }
 475         return $component[1];
 476     }
 477
 478     /**
 479      * This function allows you to retrieve the complete array of components found in
 480      * the md5filename
 481      *
 482      * @return bool|array array of components in md5 file or false if error
 483      */
 484     function get_all_components_md5() {
 485
 486     /// Check requisites are passed
 487         if (!$this->requisitesok) {
 488             return false;
 489         }
 490
 491     /// Initialize components array
 492         $comp_arr = array();
 493
 494     /// Define and retrieve the full md5 file
 495         if ($this->zippath) {
 496             $source = $this->sourcebase.'/'.$this->zippath.'/'.$this->md5filename;
 497         } else {
 498             $source = $this->sourcebase.'/'.$this->md5filename;
 499         }
 500
 501     /// Check if we have downloaded the md5 file before (per request cache)
 502         if (!empty($this->cachedmd5components[$source])) {
 503             $comp_arr = $this->cachedmd5components[$source];
 504         } else {
 505         /// Not downloaded, let's do it now
 506             $availablecomponents = array();
 507
 508             if ($contents = download_file_content($source)) {
 509             /// Split text into lines
 510                 $lines=preg_split('/\r?\n/',$contents);
 511             /// Each line will be one component
 512                 foreach($lines as $line) {
 513                     $availablecomponents[] = explode(',', $line);
 514                 }
 515             /// If no components have been found, return error
 516                 if (empty($availablecomponents)) {
 517                     $this->errorstring='cannotdownloadcomponents';
 518                     return false;
 519                 }
 520             /// Build an associative array of components for easily search
 521             /// applying trim to avoid linefeeds and other...
 522                 $comp_arr = array();
 523                 foreach ($availablecomponents as $component) {
 524                 /// Avoid sometimes empty lines
 525                     if (empty($component[0])) {
 526                         continue;
 527                     }
 528                     $component[0]=trim($component[0]);
 529                     if (!empty($component[1])) {
 530                         $component[1]=trim($component[1]);
 531                     }
 532                     if (!empty($component[2])) {
 533                         $component[2]=trim($component[2]);
 534                     }
 535                     $comp_arr[$component[0]] = $component;
 536                 }
 537             /// Cache components
 538                 $this->cachedmd5components[$source] = $comp_arr;
 539             } else {
 540             /// Return error
 541                 $this->errorstring='remotedownloaderror';
 542                 return false;
 543             }
 544         }
 545     /// If there is no commponents or erros found, error
 546         if (!empty($this->errorstring)) {
 547              return false;
 548
 549         } else if (empty($comp_arr)) {
 550              $this->errorstring='cannotdownloadcomponents';
 551              return false;
 552         }
 553         return $comp_arr;
 554     }
 555
 556     /**
 557      * This function returns the errorstring
 558      *
 559      * @return string the error string
 560      */
 561     function get_error() {
 562         return $this->errorstring;
 563     }
 564
 565     /** This function returns the extramd5 field (optional in md5 file)
 566      *
 567      * @return string the extramd5 field
 568      */
 569     function get_extra_md5_field() {
 570         return $this->extramd5info;
 571     }
 572
 573 } /// End of component_installer class
 574
 575
 576 /**
 577  * Language packs installer
 578  *
 579  * This class wraps the functionality provided by {@link component_installer}
 580  * and adds support for installing a set of language packs.
 581  *
 582  * Given an array of required language packs, this class fetches them all
 583  * and installs them. It detects eventual dependencies and installs
 584  * all parent languages, too.
 585  *
 586  * @copyright 2011 David Mudrak <david@moodle.com>
 587  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 588  */
 589 class lang_installer {
 590
 591     /** lang pack was successfully downloaded and deployed */
 592     const RESULT_INSTALLED      = 'installed';
 593     /** lang pack was up-to-date so no download was needed */
 594     const RESULT_UPTODATE       = 'uptodate';
 595     /** there was a problem with downloading the lang pack */
 596     const RESULT_DOWNLOADERROR  = 'downloaderror';
 597
 598     /** @var array of languages to install */
 599     protected $queue = array();
 600     /** @var string the code of language being currently installed */
 601     protected $current;
 602     /** @var array of languages already installed by this instance */
 603     protected $done = array();
 604     /** @var string this Moodle major version */
 605     protected $version;
 606
 607     /**
 608      * Prepare the installer
 609      *
 610      * @param string|array $langcode a code of the language to install
 611      */
 612     public function __construct($langcode = '') {
 613         global $CFG;
 614
 615         $this->set_queue($langcode);
 616         $this->version = moodle_major_version(true);
 617
 618         if (!empty($CFG->langotherroot) and $CFG->langotherroot !== $CFG->dataroot . '/lang') {
 619             debugging('The in-built language pack installer does not support alternative location ' .
 620                 'of languages root directory. You are supposed to install and update your language '.
 621                 'packs on your own.');
 622         }
 623     }
 624
 625     /**
 626      * Sets the queue of language packs to be installed
 627      *
 628      * @param string|array $langcodes language code like 'cs' or a list of them
 629      */
 630     public function set_queue($langcodes) {
 631         if (is_array($langcodes)) {
 632             $this->queue = $langcodes;
 633         } else if (!empty($langcodes)) {
 634             $this->queue = array($langcodes);
 635         }
 636     }
 637
 638     /**
 639      * Runs the installer
 640      *
 641      * This method calls {@link self::install_language_pack} for every language in the
 642      * queue. If a dependency is detected, the parent language is added to the queue.
 643      *
 644      * @return array results, array of self::RESULT_xxx constants indexed by language code
 645      */
 646     public function run() {
 647
 648         $results = array();
 649
 650         while ($this->current = array_shift($this->queue)) {
 651
 652             if ($this->was_processed($this->current)) {
 653                 // do not repeat yourself
 654                 continue;
 655             }
 656
 657             if ($this->current === 'en') {
 658                 $this->mark_processed($this->current);
 659                 continue;
 660             }
 661
 662             $results[$this->current] = $this->install_language_pack($this->current);
 663
 664             if (in_array($results[$this->current], array(self::RESULT_INSTALLED, self::RESULT_UPTODATE))) {
 665                 if ($parentlang = $this->get_parent_language($this->current)) {
 666                     if (!$this->is_queued($parentlang) and !$this->was_processed($parentlang)) {
 667                         $this->add_to_queue($parentlang);
 668                     }
 669                 }
 670             }
 671
 672             $this->mark_processed($this->current);
 673         }
 674
 675         return $results;
 676     }
 677
 678     /**
 679      * Returns the URL where a given language pack can be downloaded
 680      *
 681      * Alternatively, if the parameter is empty, returns URL of the page with the
 682      * list of all available language packs.
 683      *
 684      * @param string $langcode language code like 'cs' or empty for unknown
 685      * @return string URL
 686      */
 687     public function lang_pack_url($langcode = '') {
 688
 689         if (empty($langcode)) {
 690             return 'https://download.moodle.org/langpack/'.$this->version.'/';
 691         } else {
 692             return 'https://download.moodle.org/download.php/langpack/'.$this->version.'/'.$langcode.'.zip';
 693         }
 694     }
 695
 696     /**
 697      * Returns the list of available language packs from download.moodle.org
 698      *
 699      * @return array|bool false if can not download
 700      */
 701     public function get_remote_list_of_languages() {
 702         $source = 'https://download.moodle.org/langpack/' . $this->version . '/languages.md5';
 703         $availablelangs = array();
 704
 705         if ($content = download_file_content($source)) {
 706             $alllines = explode("\n", $content);
 707             foreach($alllines as $line) {
 708                 if (!empty($line)){
 709                     $availablelangs[] = explode(',', $line);
 710                 }
 711             }
 712             return $availablelangs;
 713
 714         } else {
 715             return false;
 716         }
 717     }
 718
 719     // Internal implementation /////////////////////////////////////////////////
 720
 721     /**
 722      * Adds a language pack (or a list of them) to the queue
 723      *
 724      * @param string|array $langcodes code of the language to install or a list of them
 725      */
 726     protected function add_to_queue($langcodes) {
 727         if (is_array($langcodes)) {
 728             $this->queue = array_merge($this->queue, $langcodes);
 729         } else if (!empty($langcodes)) {
 730             $this->queue[] = $langcodes;
 731         }
 732     }
 733
 734     /**
 735      * Checks if the given language is queued or if the queue is empty
 736      *
 737      * @example $installer->is_queued('es');    // is Spanish going to be installed?
 738      * @example $installer->is_queued();        // is there a language queued?
 739      *
 740      * @param string $langcode language code or empty string for "any"
 741      * @return boolean
 742      */
 743     protected function is_queued($langcode = '') {
 744
 745         if (empty($langcode)) {
 746             return !empty($this->queue);
 747
 748         } else {
 749             return in_array($langcode, $this->queue);
 750         }
 751     }
 752
 753     /**
 754      * Checks if the given language has already been processed by this instance
 755      *
 756      * @see self::mark_processed()
 757      * @param string $langcode
 758      * @return boolean
 759      */
 760     protected function was_processed($langcode) {
 761         return isset($this->done[$langcode]);
 762     }
 763
 764     /**
 765      * Mark the given language pack as processed
 766      *
 767      * @see self::was_processed()
 768      * @param string $langcode
 769      */
 770     protected function mark_processed($langcode) {
 771         $this->done[$langcode] = 1;
 772     }
 773
 774     /**
 775      * Returns a parent language of the given installed language
 776      *
 777      * @param string $langcode
 778      * @return string parent language's code
 779      */
 780     protected function get_parent_language($langcode) {
 781         return get_parent_language($langcode);
 782     }
 783
 784     /**
 785      * Perform the actual language pack installation
 786      *
 787      * @uses component_installer
 788      * @param string $langcode
 789      * @return int return status
 790      */
 791     protected function install_language_pack($langcode) {
 792
 793         // initialise new component installer to process this language
 794         $installer = new component_installer('https://download.moodle.org', 'download.php/direct/langpack/' . $this->version,
 795             $langcode . '.zip', 'languages.md5', 'lang');
 796
 797         if (!$installer->requisitesok) {
 798             throw new lang_installer_exception('installer_requisites_check_failed');
 799         }
 800
 801         $status = $installer->install();
 802
 803         if ($status == COMPONENT_ERROR) {
 804             if ($installer->get_error() === 'remotedownloaderror') {
 805                 return self::RESULT_DOWNLOADERROR;
 806             } else {
 807                 throw new lang_installer_exception($installer->get_error(), $langcode);
 808             }
 809
 810         } else if ($status == COMPONENT_UPTODATE) {
 811             return self::RESULT_UPTODATE;
 812
 813         } else if ($status == COMPONENT_INSTALLED) {
 814             return self::RESULT_INSTALLED;
 815
 816         } else {
 817             throw new lang_installer_exception('unexpected_installer_result', $status);
 818         }
 819     }
 820 }
 821
 822
 823 /**
 824  * Exception thrown by {@link lang_installer}
 825  *
 826  * @copyright 2011 David Mudrak <david@moodle.com>
 827  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 828  */
 829 class lang_installer_exception extends moodle_exception {
 830
 831     public function __construct($errorcode, $debuginfo = null) {
 832         parent::__construct($errorcode, 'error', '', null, $debuginfo);
 833     }
 834 }