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Differences Between: [Versions 310 and 402] [Versions 311 and 402] [Versions 400 and 402]

   1  <?php
   2  // This file is part of Moodle - http://moodle.org/
   3  //
   4  // Moodle is free software: you can redistribute it and/or modify
   5  // it under the terms of the GNU General Public License as published by
   6  // the Free Software Foundation, either version 3 of the License, or
   7  // (at your option) any later version.
   8  //
   9  // Moodle is distributed in the hope that it will be useful,
  10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  // GNU General Public License for more details.
  13  //
  14  // You should have received a copy of the GNU General Public License
  15  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16  
  17  /**
  18   * Zip writer wrapper.
  19   *
  20   * @package     core
  21   * @copyright   2020 Simey Lameze <simey@moodle.com>
  22   * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  namespace core\content\export;
  25  
  26  use context;
  27  use context_system;
  28  use moodle_url;
  29  use stdClass;
  30  use stored_file;
  31  
  32  /**
  33   * Zip writer wrapper.
  34   *
  35   * @copyright   2020 Simey Lameze <simey@moodle.com>
  36   * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  37   */
  38  class zipwriter {
  39  
  40      /** @var int Maximum folder length name for a context */
  41      const MAX_CONTEXT_NAME_LENGTH = 32;
  42  
  43      /** @var \ZipStream\ZipStream */
  44      protected $archive;
  45  
  46      /** @var int Max file size of an individual file in the archive */
  47      protected $maxfilesize = 1 * 1024 * 1024 * 10;
  48  
  49      /** @var resource File resource for the file handle for a file-based zip stream */
  50      protected $zipfilehandle = null;
  51  
  52      /** @var string File path for a file-based zip stream */
  53      protected $zipfilepath = null;
  54  
  55      /** @var context The context to use as a base for export */
  56      protected $rootcontext = null;
  57  
  58      /** @var array The files in the zip */
  59      protected $filesinzip = [];
  60  
  61      /** @var bool Whether page requirements needed for HTML pages have been added */
  62      protected $pagerequirementsadded = false;
  63  
  64      /** @var stdClass The course relating to the root context */
  65      protected $course;
  66  
  67      /** @var context The context of the course for the root contect */
  68      protected $coursecontext;
  69  
  70      /**
  71       * zipwriter constructor.
  72       *
  73       * @param \ZipStream\ZipStream $archive
  74       * @param stdClass|null $options
  75       */
  76      public function __construct(\ZipStream\ZipStream $archive, stdClass $options = null) {
  77          $this->archive = $archive;
  78          if ($options) {
  79              $this->parse_options($options);
  80          }
  81  
  82          $this->rootcontext = context_system::instance();
  83      }
  84  
  85      /**
  86       * Set a root context for use during the export.
  87       *
  88       * This is primarily used for creating paths within the archive relative to the root context.
  89       *
  90       * @param   context $rootcontext
  91       */
  92      public function set_root_context(context $rootcontext): void {
  93          $this->rootcontext = $rootcontext;
  94      }
  95  
  96      /**
  97       * Get the course object for the root context.
  98       *
  99       * @return  stdClass
 100       */
 101      protected function get_course(): stdClass {
 102          if ($this->course && ($this->coursecontext !== $this->rootcontext->get_course_context())) {
 103              $this->coursecontext = null;
 104              $this->course = null;
 105          }
 106          if (empty($this->course)) {
 107              $this->coursecontext = $this->rootcontext->get_course_context();
 108              $this->course = get_course($this->coursecontext->instanceid);
 109          }
 110  
 111          return $this->course;
 112      }
 113  
 114      /**
 115       * Parse options.
 116       *
 117       * @param stdClass $options
 118       */
 119      protected function parse_options(stdClass $options): void {
 120          if (property_exists($options, 'maxfilesize')) {
 121              $this->maxfilesize = $options->maxfilesize;
 122          }
 123      }
 124  
 125      /**
 126       * Finish writing the zip footer.
 127       */
 128      public function finish(): void {
 129          $this->archive->finish();
 130  
 131          if ($this->zipfilehandle) {
 132              fclose($this->zipfilehandle);
 133          }
 134      }
 135  
 136      /**
 137       * Get the stream writer.
 138       *
 139       * @param string $filename
 140       * @param stdClass|null $exportoptions
 141       * @return static
 142       */
 143      public static function get_stream_writer(string $filename, stdClass $exportoptions = null) {
 144          $options = new \ZipStream\Option\Archive();
 145          $options->setSendHttpHeaders(true);
 146          $archive = new \ZipStream\ZipStream($filename, $options);
 147  
 148          $zipwriter = new static($archive, $exportoptions);
 149  
 150          \core\session\manager::write_close();
 151          return $zipwriter;
 152      }
 153  
 154      /**
 155       * Get the file writer.
 156       *
 157       * @param string $filename
 158       * @param stdClass|null $exportoptions
 159       * @return static
 160       */
 161      public static function get_file_writer(string $filename, stdClass $exportoptions = null) {
 162          $options = new \ZipStream\Option\Archive();
 163  
 164          $dir = make_request_directory();
 165          $filepath = $dir . "/$filename";
 166          $fh = fopen($filepath, 'w');
 167  
 168          $options->setOutputStream($fh);
 169          $options->setSendHttpHeaders(false);
 170          $archive = new \ZipStream\ZipStream($filename, $options);
 171  
 172          $zipwriter = new static($archive, $exportoptions);
 173  
 174          $zipwriter->zipfilehandle = $fh;
 175          $zipwriter->zipfilepath = $filepath;
 176  
 177          \core\session\manager::write_close();
 178          return $zipwriter;
 179      }
 180  
 181      /**
 182       * Get the file path for a file-based zip writer.
 183       *
 184       * If this is not a file-based writer then no value is returned.
 185       *
 186       * @return  null|string
 187       */
 188      public function get_file_path(): ?string {
 189          return $this->zipfilepath;
 190      }
 191  
 192      /**
 193       * Add a file from the File Storage API.
 194       *
 195       * @param   context $context
 196       * @param   string $filepathinzip
 197       * @param   stored_file $file The file to add
 198       */
 199      public function add_file_from_stored_file(
 200          context $context,
 201          string $filepathinzip,
 202          stored_file $file
 203      ): void {
 204          $fullfilepathinzip = $this->get_context_path($context, $filepathinzip);
 205  
 206          if ($file->get_filesize() <= $this->maxfilesize) {
 207              $filehandle = $file->get_content_file_handle();
 208              $this->archive->addFileFromStream($fullfilepathinzip, $filehandle);
 209              fclose($filehandle);
 210  
 211              $this->filesinzip[] = $fullfilepathinzip;
 212          }
 213      }
 214  
 215      /**
 216       * Add a file from string content.
 217       *
 218       * @param   context $context
 219       * @param   string $filepathinzip
 220       * @param   string $content
 221       */
 222      public function add_file_from_string(
 223          context $context,
 224          string $filepathinzip,
 225          string $content
 226      ): void {
 227          $fullfilepathinzip = $this->get_context_path($context, $filepathinzip);
 228  
 229          $this->archive->addFile($fullfilepathinzip, $content);
 230  
 231          $this->filesinzip[] = $fullfilepathinzip;
 232      }
 233  
 234      /**
 235       * Create a file based on a Mustache Template and associated data.
 236       *
 237       * @param   context $context
 238       * @param   string $filepathinzip
 239       * @param   string $template
 240       * @param   stdClass $templatedata
 241       */
 242      public function add_file_from_template(
 243          context $context,
 244          string $filepathinzip,
 245          string $template,
 246          stdClass $templatedata
 247      ): void {
 248          global $CFG, $PAGE, $SITE, $USER;
 249  
 250          $exportedcourse = $this->get_course();
 251          $courselink = (new moodle_url('/course/view.php', ['id' => $exportedcourse->id]))->out(false);
 252          $coursename = format_string($exportedcourse->fullname, true, ['context' => $this->coursecontext]);
 253  
 254          $this->add_template_requirements();
 255  
 256          $templatedata->global = (object) [
 257              'righttoleft' => right_to_left(),
 258              'language' => get_html_lang_attribute_value(current_language()),
 259              'sitename' => format_string($SITE->fullname, true, ['context' => context_system::instance()]),
 260              'siteurl' => $CFG->wwwroot,
 261              'pathtotop' => $this->get_relative_context_path($context, $this->rootcontext, '/'),
 262              'contentexportfooter' => get_string('contentexport_footersummary', 'core', (object) [
 263                  'courselink' => $courselink,
 264                  'coursename' => $coursename,
 265                  'userfullname' => fullname($USER),
 266                  'date' => userdate(time()),
 267              ]),
 268              'contentexportsummary' => get_string('contentexport_coursesummary', 'core', (object) [
 269                  'courselink' => $courselink,
 270                  'coursename' => $coursename,
 271                  'date' => userdate(time()),
 272              ]),
 273              'coursename' => $coursename,
 274              'courseshortname' => $exportedcourse->shortname,
 275              'courselink' => $courselink,
 276              'exportdate' => userdate(time()),
 277              'maxfilesize' => display_size($this->maxfilesize, 0),
 278          ];
 279  
 280          $renderer = $PAGE->get_renderer('core');
 281          $this->add_file_from_string($context, $filepathinzip, $renderer->render_from_template($template, $templatedata));
 282      }
 283  
 284      /**
 285       * Ensure that all requirements for a templated page are present.
 286       *
 287       * This includes CSS, and any other similar content.
 288       */
 289      protected function add_template_requirements(): void {
 290          if ($this->pagerequirementsadded) {
 291              return;
 292          }
 293  
 294          // CSS required.
 295          $this->add_content_from_dirroot('/theme/boost/style/moodle.css', 'shared/moodle.css');
 296  
 297          $this->pagerequirementsadded = true;
 298      }
 299  
 300      /**
 301       * Add content from the dirroot into the specified path in the zip file.
 302       *
 303       * @param   string $dirrootpath
 304       * @param   string $pathinzip
 305       */
 306      protected function add_content_from_dirroot(string $dirrootpath, string $pathinzip): void {
 307          global $CFG;
 308  
 309          $this->archive->addFileFromPath(
 310              $this->get_context_path($this->rootcontext, $pathinzip),
 311              "{$CFG->dirroot}/{$dirrootpath}"
 312          );
 313      }
 314  
 315      /**
 316       * Check whether the file was actually added to the archive.
 317       *
 318       * @param   context $context
 319       * @param   string $filepathinzip
 320       * @return  bool
 321       */
 322      public function is_file_in_archive(context $context, string $filepathinzip): bool {
 323          $fullfilepathinzip = $this->get_context_path($context, $filepathinzip);
 324  
 325          return in_array($fullfilepathinzip, $this->filesinzip);
 326      }
 327  
 328      /**
 329       * Get the full path to the context within the zip.
 330       *
 331       * @param   context $context
 332       * @param   string $filepathinzip
 333       * @return  string
 334       */
 335      public function get_context_path(context $context, string $filepathinzip): string {
 336          if (!$context->is_child_of($this->rootcontext, true)) {
 337              throw new \coding_exception("Unexpected path requested");
 338          }
 339  
 340          // Fetch the path from the course down.
 341          $parentcontexts = array_filter(
 342              $context->get_parent_contexts(true),
 343              function(context $curcontext): bool {
 344                  return $curcontext->is_child_of($this->rootcontext, true);
 345              }
 346          );
 347  
 348          foreach (array_reverse($parentcontexts) as $curcontext) {
 349              $path[] = $this->get_context_folder_name($curcontext);
 350          }
 351  
 352          $path[] = $filepathinzip;
 353  
 354          $finalpath = implode(DIRECTORY_SEPARATOR, $path);
 355  
 356          // Remove relative paths (./).
 357          $finalpath = str_replace('./', '/', $finalpath);
 358  
 359          // De-duplicate slashes.
 360          $finalpath = str_replace('//', '/', $finalpath);
 361  
 362          // Remove leading /.
 363          ltrim($finalpath, '/');
 364  
 365          return $this->sanitise_filename($finalpath);
 366      }
 367  
 368      /**
 369       * Get a relative path to the specified context path.
 370       *
 371       * @param   context $rootcontext
 372       * @param   context $targetcontext
 373       * @param   string $filepathinzip
 374       * @return  string
 375       */
 376      public function get_relative_context_path(context $rootcontext, context $targetcontext, string $filepathinzip): string {
 377          $path = [];
 378          if ($targetcontext === $rootcontext) {
 379              $lookupcontexts = [];
 380          } else if ($targetcontext->is_child_of($rootcontext, true)) {
 381              // Fetch the path from the course down.
 382              $lookupcontexts = array_filter(
 383                  $targetcontext->get_parent_contexts(true),
 384                  function(context $curcontext): bool {
 385                      return $curcontext->is_child_of($this->rootcontext, false);
 386                  }
 387              );
 388  
 389              foreach ($lookupcontexts as $curcontext) {
 390                  array_unshift($path, $this->get_context_folder_name($curcontext));
 391              }
 392          } else if ($targetcontext->is_parent_of($rootcontext, true)) {
 393              $lookupcontexts = $targetcontext->get_parent_contexts(true);
 394              $path[] = '..';
 395          }
 396  
 397          $path[] = $filepathinzip;
 398          $relativepath = implode(DIRECTORY_SEPARATOR, $path);
 399  
 400          // De-duplicate slashes and remove leading /.
 401          $relativepath = ltrim(preg_replace('#/+#', '/', $relativepath), '/');
 402  
 403          if (substr($relativepath, 0, 1) !== '.') {
 404              $relativepath = "./{$relativepath}";
 405          }
 406  
 407          return $this->sanitise_filename($relativepath);
 408      }
 409  
 410      /**
 411       * Sanitise the file path, removing any unsuitable characters.
 412       *
 413       * @param   string $filepath
 414       * @return  string
 415       */
 416      protected function sanitise_filename(string $filepath): string {
 417          // The filename must be sanitised in the same as the parent ZipStream library.
 418          return \ZipStream\File::filterFilename($filepath);
 419      }
 420  
 421      /**
 422       * Get the name of the folder for the specified context.
 423       *
 424       * @param   context $context
 425       * @return  string
 426       */
 427      protected function get_context_folder_name(context $context): string {
 428          // Replace spaces with underscores, or they will be removed completely when cleaning.
 429          $contextname = str_replace(' ', '_', $context->get_context_name());
 430  
 431          // Clean the context name of all but basic characters, as some systems don't support unicode within zip structure.
 432          $shortenedname = shorten_text(
 433              clean_param($contextname, PARAM_SAFEDIR),
 434              self::MAX_CONTEXT_NAME_LENGTH,
 435              true
 436          );
 437  
 438          return "{$shortenedname}_.{$context->id}";
 439      }
 440  
 441      /**
 442       * Rewrite any pluginfile URLs in the content.
 443       *
 444       * @param   context $context
 445       * @param   string $content
 446       * @param   string $component
 447       * @param   string $filearea
 448       * @param   null|int $pluginfileitemid The itemid to use in the pluginfile URL when composing any required URLs
 449       * @return  string
 450       */
 451      protected function rewrite_other_pluginfile_urls(
 452          context $context,
 453          string $content,
 454          string $component,
 455          string $filearea,
 456          ?int $pluginfileitemid
 457      ): string {
 458          // The pluginfile URLs should have been rewritten when the files were exported, but if any file was too large it
 459          // may not have been included.
 460          // In that situation use a tokenpluginfile URL.
 461  
 462          if (strpos($content, '@@PLUGINFILE@@/') !== false) {
 463              // Some files could not be rewritten.
 464              // Use a tokenurl pluginfile for those.
 465              $content = file_rewrite_pluginfile_urls(
 466                  $content,
 467                  'pluginfile.php',
 468                  $context->id,
 469                  $component,
 470                  $filearea,
 471                  $pluginfileitemid,
 472                  [
 473                      'includetoken' => true,
 474                  ]
 475              );
 476          }
 477  
 478          return $content;
 479      }
 480  
 481      /**
 482       * Export files releating to this text area.
 483       *
 484       * @param   context $context
 485       * @param   string $subdir The sub directory to export any files to
 486       * @param   string $content
 487       * @param   string $component
 488       * @param   string $filearea
 489       * @param   int $fileitemid The itemid as used in the Files API
 490       * @param   null|int $pluginfileitemid The itemid to use in the pluginfile URL when composing any required URLs
 491       * @return  exported_item
 492       */
 493      public function add_pluginfiles_for_content(
 494          context $context,
 495          string $subdir,
 496          string $content,
 497          string $component,
 498          string $filearea,
 499          int $fileitemid,
 500          ?int $pluginfileitemid
 501      ): exported_item {
 502          // Export all of the files for this text area.
 503          $fs = get_file_storage();
 504          $files = $fs->get_area_files($context->id, $component, $filearea, $fileitemid);
 505  
 506          $result = new exported_item();
 507          foreach ($files as $file) {
 508              if ($file->is_directory()) {
 509                  continue;
 510              }
 511  
 512              $filepathinzip = self::get_filepath_for_file($file, $subdir, false);
 513              $this->add_file_from_stored_file(
 514                  $context,
 515                  $filepathinzip,
 516                  $file
 517              );
 518  
 519              if ($this->is_file_in_archive($context, $filepathinzip)) {
 520                  // Attempt to rewrite any @@PLUGINFILE@@ URLs for this file in the content.
 521                  $searchpath = "@@PLUGINFILE@@" . $file->get_filepath() . rawurlencode($file->get_filename());
 522                  if (strpos($content, $searchpath) !== false) {
 523                      $content = str_replace($searchpath, self::get_filepath_for_file($file, $subdir, true), $content);
 524                      $result->add_file($filepathinzip, true);
 525                  } else {
 526                      $result->add_file($filepathinzip, false);
 527                  }
 528              }
 529  
 530          }
 531  
 532          $content = $this->rewrite_other_pluginfile_urls($context, $content, $component, $filearea, $pluginfileitemid);
 533          $result->set_content($content);
 534  
 535          return $result;
 536      }
 537  
 538      /**
 539       * Get the filepath for the specified stored_file.
 540       *
 541       * @param   stored_file $file
 542       * @param   string $parentdir Any parent directory to place this file in
 543       * @param   bool $escape
 544       * @return  string
 545       */
 546      protected static function get_filepath_for_file(stored_file $file, string $parentdir, bool $escape): string {
 547          $path = [];
 548  
 549          $filepath = sprintf(
 550              '%s/%s/%s/%s',
 551              $parentdir,
 552              $file->get_filearea(),
 553              $file->get_filepath(),
 554              $file->get_filename()
 555          );
 556  
 557          if ($escape) {
 558              foreach (explode('/', $filepath) as $dirname) {
 559                  $path[] = rawurlencode($dirname);
 560              }
 561              $filepath = implode('/', $path);
 562          }
 563  
 564          return ltrim(preg_replace('#/+#', '/', $filepath), '/');
 565      }
 566  
 567  }