includes/resourceloader/ResourceLoaderModule.php

   1 <?php
   2 /**
   3  * Abstraction for ResourceLoader modules.
   4  *
   5  * This program 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 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program 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 along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Trevor Parscal
  22  * @author Roan Kattouw
  23  */
  24
  25 use MediaWiki\MediaWikiServices;
  26 use Psr\Log\LoggerAwareInterface;
  27 use Psr\Log\LoggerInterface;
  28 use Psr\Log\NullLogger;
  29 use Wikimedia\AtEase\AtEase;
  30 use Wikimedia\RelPath;
  31 use Wikimedia\ScopedCallback;
  32
  33 /**
  34  * Abstraction for ResourceLoader modules, with name registration and maxage functionality.
  35  */
  36 abstract class ResourceLoaderModule implements LoggerAwareInterface {
  37         /** @var Config */
  38         protected $config;
  39         /** @var LoggerInterface */
  40         protected $logger;
  41
  42         /**
  43          * Script and style modules form a hierarchy of trustworthiness, with core modules
  44          * like skins and jQuery as most trustworthy, and user scripts as least trustworthy. We can
  45          * limit the types of scripts and styles we allow to load on, say, sensitive special
  46          * pages like Special:UserLogin and Special:Preferences
  47          * @var int
  48          */
  49         protected $origin = self::ORIGIN_CORE_SITEWIDE;
  50
  51         /** @var string|null Module name */
  52         protected $name = null;
  53         /** @var string[] What client platforms the module targets (e.g. desktop, mobile) */
  54         protected $targets = [ 'desktop' ];
  55
  56         /** @var array Map of (variant => indirect file dependencies) */
  57         protected $fileDeps = [];
  58         /** @var array Map of (language => in-object cache for message blob) */
  59         protected $msgBlobs = [];
  60         /** @var array Map of (context hash => cached module version hash) */
  61         protected $versionHash = [];
  62         /** @var array Map of (context hash => cached module content) */
  63         protected $contents = [];
  64
  65         /** @var string|bool Deprecation string or true if deprecated; false otherwise */
  66         protected $deprecated = false;
  67
  68         /** @var string Scripts only */
  69         const TYPE_SCRIPTS = 'scripts';
  70         /** @var string Styles only */
  71         const TYPE_STYLES = 'styles';
  72         /** @var string Scripts and styles */
  73         const TYPE_COMBINED = 'combined';
  74
  75         /** @var string Module only has styles (loaded via <style> or <link rel=stylesheet>) */
  76         const LOAD_STYLES = 'styles';
  77         /** @var string Module may have other resources (loaded via mw.loader from a script) */
  78         const LOAD_GENERAL = 'general';
  79
  80         /** @var int Sitewide core module like a skin file or jQuery component */
  81         const ORIGIN_CORE_SITEWIDE = 1;
  82         /** @var int Per-user module generated by the software */
  83         const ORIGIN_CORE_INDIVIDUAL = 2;
  84         /**
  85          * Sitewide module generated from user-editable files, like MediaWiki:Common.js,
  86          * or modules accessible to multiple users, such as those generated by the Gadgets extension.
  87          * @var int
  88          */
  89         const ORIGIN_USER_SITEWIDE = 3;
  90         /** @var int Per-user module generated from user-editable files, like User:Me/vector.js */
  91         const ORIGIN_USER_INDIVIDUAL = 4;
  92         /** @var int An access constant; make sure this is kept as the largest number in this group */
  93         const ORIGIN_ALL = 10;
  94
  95         /**
  96          * Get this module's name. This is set when the module is registered
  97          * with ResourceLoader::register()
  98          *
  99          * @return string|null Name (string) or null if no name was set
 100          */
 101         public function getName() {
 102                 return $this->name;
 103         }
 104
 105         /**
 106          * Set this module's name. This is called by ResourceLoader::register()
 107          * when registering the module. Other code should not call this.
 108          *
 109          * @param string $name
 110          */
 111         public function setName( $name ) {
 112                 $this->name = $name;
 113         }
 114
 115         /**
 116          * Get this module's origin. This is set when the module is registered
 117          * with ResourceLoader::register()
 118          *
 119          * @return int ResourceLoaderModule class constant, the subclass default
 120          *     if not set manually
 121          */
 122         public function getOrigin() {
 123                 return $this->origin;
 124         }
 125
 126         /**
 127          * @param ResourceLoaderContext $context
 128          * @return bool
 129          */
 130         public function getFlip( $context ) {
 131                 return MediaWikiServices::getInstance()->getContentLanguage()->getDir() !==
 132                         $context->getDirection();
 133         }
 134
 135         /**
 136          * Get JS representing deprecation information for the current module if available
 137          *
 138          * @return string JavaScript code
 139          */
 140         public function getDeprecationInformation() {
 141                 $deprecationInfo = $this->deprecated;
 142                 if ( $deprecationInfo ) {
 143                         $name = $this->getName();
 144                         $warning = 'This page is using the deprecated ResourceLoader module "' . $name . '".';
 145                         if ( is_string( $deprecationInfo ) ) {
 146                                 $warning .= "\n" . $deprecationInfo;
 147                         }
 148                         return 'mw.log.warn(' . ResourceLoader::encodeJsonForScript( $warning ) . ');';
 149                 } else {
 150                         return '';
 151                 }
 152         }
 153
 154         /**
 155          * Get all JS for this module for a given language and skin.
 156          * Includes all relevant JS except loader scripts.
 157          *
 158          * For "plain" script modules, this should return a string with JS code. For multi-file modules
 159          * where require() is used to load one file from another file, this should return an array
 160          * structured as follows:
 161          * [
 162          *     'files' => [
 163          *         'file1.js' => [ 'type' => 'script', 'content' => 'JS code' ],
 164          *         'file2.js' => [ 'type' => 'script', 'content' => 'JS code' ],
 165          *         'data.json' => [ 'type' => 'data', 'content' => array ]
 166          *     ],
 167          *     'main' => 'file1.js'
 168          * ]
 169          *
 170          * @param ResourceLoaderContext $context
 171          * @return string|array JavaScript code (string), or multi-file structure described above (array)
 172          */
 173         public function getScript( ResourceLoaderContext $context ) {
 174                 // Stub, override expected
 175                 return '';
 176         }
 177
 178         /**
 179          * Takes named templates by the module and returns an array mapping.
 180          *
 181          * @return string[] Array of templates mapping template alias to content
 182          */
 183         public function getTemplates() {
 184                 // Stub, override expected.
 185                 return [];
 186         }
 187
 188         /**
 189          * @return Config
 190          * @since 1.24
 191          */
 192         public function getConfig() {
 193                 if ( $this->config === null ) {
 194                         // Ugh, fall back to default
 195                         $this->config = MediaWikiServices::getInstance()->getMainConfig();
 196                 }
 197
 198                 return $this->config;
 199         }
 200
 201         /**
 202          * @param Config $config
 203          * @since 1.24
 204          */
 205         public function setConfig( Config $config ) {
 206                 $this->config = $config;
 207         }
 208
 209         /**
 210          * @since 1.27
 211          * @param LoggerInterface $logger
 212          */
 213         public function setLogger( LoggerInterface $logger ) {
 214                 $this->logger = $logger;
 215         }
 216
 217         /**
 218          * @since 1.27
 219          * @return LoggerInterface
 220          */
 221         protected function getLogger() {
 222                 if ( !$this->logger ) {
 223                         $this->logger = new NullLogger();
 224                 }
 225                 return $this->logger;
 226         }
 227
 228         /**
 229          * Get the URL or URLs to load for this module's JS in debug mode.
 230          * The default behavior is to return a load.php?only=scripts URL for
 231          * the module, but file-based modules will want to override this to
 232          * load the files directly.
 233          *
 234          * This function is called only when 1) we're in debug mode, 2) there
 235          * is no only= parameter and 3) supportsURLLoading() returns true.
 236          * #2 is important to prevent an infinite loop, therefore this function
 237          * MUST return either an only= URL or a non-load.php URL.
 238          *
 239          * @param ResourceLoaderContext $context
 240          * @return array Array of URLs
 241          */
 242         public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
 243                 $resourceLoader = $context->getResourceLoader();
 244                 $derivative = new DerivativeResourceLoaderContext( $context );
 245                 $derivative->setModules( [ $this->getName() ] );
 246                 $derivative->setOnly( 'scripts' );
 247                 $derivative->setDebug( true );
 248
 249                 $url = $resourceLoader->createLoaderURL(
 250                         $this->getSource(),
 251                         $derivative
 252                 );
 253
 254                 return [ $url ];
 255         }
 256
 257         /**
 258          * Whether this module supports URL loading. If this function returns false,
 259          * getScript() will be used even in cases (debug mode, no only param) where
 260          * getScriptURLsForDebug() would normally be used instead.
 261          * @return bool
 262          */
 263         public function supportsURLLoading() {
 264                 return true;
 265         }
 266
 267         /**
 268          * Get all CSS for this module for a given skin.
 269          *
 270          * @param ResourceLoaderContext $context
 271          * @return array List of CSS strings or array of CSS strings keyed by media type.
 272          *  like [ 'screen' => '.foo { width: 0 }' ];
 273          *  or [ 'screen' => [ '.foo { width: 0 }' ] ];
 274          */
 275         public function getStyles( ResourceLoaderContext $context ) {
 276                 // Stub, override expected
 277                 return [];
 278         }
 279
 280         /**
 281          * Get the URL or URLs to load for this module's CSS in debug mode.
 282          * The default behavior is to return a load.php?only=styles URL for
 283          * the module, but file-based modules will want to override this to
 284          * load the files directly. See also getScriptURLsForDebug()
 285          *
 286          * @param ResourceLoaderContext $context
 287          * @return array [ mediaType => [ URL1, URL2, ... ], ... ]
 288          */
 289         public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
 290                 $resourceLoader = $context->getResourceLoader();
 291                 $derivative = new DerivativeResourceLoaderContext( $context );
 292                 $derivative->setModules( [ $this->getName() ] );
 293                 $derivative->setOnly( 'styles' );
 294                 $derivative->setDebug( true );
 295
 296                 $url = $resourceLoader->createLoaderURL(
 297                         $this->getSource(),
 298                         $derivative
 299                 );
 300
 301                 return [ 'all' => [ $url ] ];
 302         }
 303
 304         /**
 305          * Get the messages needed for this module.
 306          *
 307          * To get a JSON blob with messages, use MessageBlobStore::get()
 308          *
 309          * @return array List of message keys. Keys may occur more than once
 310          */
 311         public function getMessages() {
 312                 // Stub, override expected
 313                 return [];
 314         }
 315
 316         /**
 317          * Get the group this module is in.
 318          *
 319          * @return string Group name
 320          */
 321         public function getGroup() {
 322                 // Stub, override expected
 323                 return null;
 324         }
 325
 326         /**
 327          * Get the source of this module. Should only be overridden for foreign modules.
 328          *
 329          * @return string Source name, 'local' for local modules
 330          */
 331         public function getSource() {
 332                 // Stub, override expected
 333                 return 'local';
 334         }
 335
 336         /**
 337          * Get a list of modules this module depends on.
 338          *
 339          * Dependency information is taken into account when loading a module
 340          * on the client side.
 341          *
 342          * Note: It is expected that $context will be made non-optional in the near
 343          * future.
 344          *
 345          * @param ResourceLoaderContext|null $context
 346          * @return array List of module names as strings
 347          */
 348         public function getDependencies( ResourceLoaderContext $context = null ) {
 349                 // Stub, override expected
 350                 return [];
 351         }
 352
 353         /**
 354          * Get target(s) for the module, eg ['desktop'] or ['desktop', 'mobile']
 355          *
 356          * @return array Array of strings
 357          */
 358         public function getTargets() {
 359                 return $this->targets;
 360         }
 361
 362         /**
 363          * Get the module's load type.
 364          *
 365          * @since 1.28
 366          * @return string ResourceLoaderModule LOAD_* constant
 367          */
 368         public function getType() {
 369                 return self::LOAD_GENERAL;
 370         }
 371
 372         /**
 373          * Get the skip function.
 374          *
 375          * Modules that provide fallback functionality can provide a "skip function". This
 376          * function, if provided, will be passed along to the module registry on the client.
 377          * When this module is loaded (either directly or as a dependency of another module),
 378          * then this function is executed first. If the function returns true, the module will
 379          * instantly be considered "ready" without requesting the associated module resources.
 380          *
 381          * The value returned here must be valid javascript for execution in a private function.
 382          * It must not contain the "function () {" and "}" wrapper though.
 383          *
 384          * @return string|null A JavaScript function body returning a boolean value, or null
 385          */
 386         public function getSkipFunction() {
 387                 return null;
 388         }
 389
 390         /**
 391          * Get the files this module depends on indirectly for a given skin.
 392          *
 393          * These are only image files referenced by the module's stylesheet.
 394          *
 395          * @param ResourceLoaderContext $context
 396          * @return array List of files
 397          */
 398         protected function getFileDependencies( ResourceLoaderContext $context ) {
 399                 $vary = self::getVary( $context );
 400
 401                 // Try in-object cache first
 402                 if ( !isset( $this->fileDeps[$vary] ) ) {
 403                         $dbr = wfGetDB( DB_REPLICA );
 404                         $deps = $dbr->selectField( 'module_deps',
 405                                 'md_deps',
 406                                 [
 407                                         'md_module' => $this->getName(),
 408                                         'md_skin' => $vary,
 409                                 ],
 410                                 __METHOD__
 411                         );
 412
 413                         if ( !is_null( $deps ) ) {
 414                                 $this->fileDeps[$vary] = self::expandRelativePaths(
 415                                         (array)json_decode( $deps, true )
 416                                 );
 417                         } else {
 418                                 $this->fileDeps[$vary] = [];
 419                         }
 420                 }
 421                 return $this->fileDeps[$vary];
 422         }
 423
 424         /**
 425          * Set in-object cache for file dependencies.
 426          *
 427          * This is used to retrieve data in batches. See ResourceLoader::preloadModuleInfo().
 428          * To save the data, use saveFileDependencies().
 429          *
 430          * @param ResourceLoaderContext $context
 431          * @param string[] $files Array of file names
 432          */
 433         public function setFileDependencies( ResourceLoaderContext $context, $files ) {
 434                 $vary = self::getVary( $context );
 435                 $this->fileDeps[$vary] = $files;
 436         }
 437
 438         /**
 439          * Set the files this module depends on indirectly for a given skin.
 440          *
 441          * @since 1.27
 442          * @param ResourceLoaderContext $context
 443          * @param array $localFileRefs List of files
 444          */
 445         protected function saveFileDependencies( ResourceLoaderContext $context, $localFileRefs ) {
 446                 try {
 447                         // Related bugs and performance considerations:
 448                         // 1. Don't needlessly change the database value with the same list in a
 449                         //    different order or with duplicates.
 450                         // 2. Use relative paths to avoid ghost entries when $IP changes. (T111481)
 451                         // 3. Don't needlessly replace the database with the same value
 452                         //    just because $IP changed (e.g. when upgrading a wiki).
 453                         // 4. Don't create an endless replace loop on every request for this
 454                         //    module when '../' is used anywhere. Even though both are expanded
 455                         //    (one expanded by getFileDependencies from the DB, the other is
 456                         //    still raw as originally read by RL), the latter has not
 457                         //    been normalized yet.
 458
 459                         // Normalise
 460                         $localFileRefs = array_values( array_unique( $localFileRefs ) );
 461                         sort( $localFileRefs );
 462                         $localPaths = self::getRelativePaths( $localFileRefs );
 463                         $storedPaths = self::getRelativePaths( $this->getFileDependencies( $context ) );
 464
 465                         if ( $localPaths === $storedPaths ) {
 466                                 // Unchanged. Avoid needless database query (especially master conn!).
 467                                 return;
 468                         }
 469
 470                         // The file deps list has changed, we want to update it.
 471                         $vary = self::getVary( $context );
 472                         $cache = ObjectCache::getLocalClusterInstance();
 473                         $key = $cache->makeKey( __METHOD__, $this->getName(), $vary );
 474                         $scopeLock = $cache->getScopedLock( $key, 0 );
 475                         if ( !$scopeLock ) {
 476                                 // Another request appears to be doing this update already.
 477                                 // Avoid write slams (T124649).
 478                                 return;
 479                         }
 480
 481                         // No needless escaping as this isn't HTML output.
 482                         // Only stored in the database and parsed in PHP.
 483                         $deps = json_encode( $localPaths, JSON_UNESCAPED_SLASHES );
 484                         $dbw = wfGetDB( DB_MASTER );
 485                         $dbw->upsert( 'module_deps',
 486                                 [
 487                                         'md_module' => $this->getName(),
 488                                         'md_skin' => $vary,
 489                                         'md_deps' => $deps,
 490                                 ],
 491                                 [ [ 'md_module', 'md_skin' ] ],
 492                                 [
 493                                         'md_deps' => $deps,
 494                                 ],
 495                                 __METHOD__
 496                         );
 497
 498                         if ( $dbw->trxLevel() ) {
 499                                 $dbw->onTransactionResolution(
 500                                         function () use ( &$scopeLock ) {
 501                                                 ScopedCallback::consume( $scopeLock ); // release after commit
 502                                         },
 503                                         __METHOD__
 504                                 );
 505                         }
 506                 } catch ( Exception $e ) {
 507                         // Probably a DB failure. Either the read query from getFileDependencies(),
 508                         // or the write query above.
 509                         wfDebugLog( 'resourceloader', __METHOD__ . ": failed to update DB: $e" );
 510                 }
 511         }
 512
 513         /**
 514          * Make file paths relative to MediaWiki directory.
 515          *
 516          * This is used to make file paths safe for storing in a database without the paths
 517          * becoming stale or incorrect when MediaWiki is moved or upgraded (T111481).
 518          *
 519          * @since 1.27
 520          * @param array $filePaths
 521          * @return array
 522          */
 523         public static function getRelativePaths( array $filePaths ) {
 524                 global $IP;
 525                 return array_map( function ( $path ) use ( $IP ) {
 526                         return RelPath::getRelativePath( $path, $IP );
 527                 }, $filePaths );
 528         }
 529
 530         /**
 531          * Expand directories relative to $IP.
 532          *
 533          * @since 1.27
 534          * @param array $filePaths
 535          * @return array
 536          */
 537         public static function expandRelativePaths( array $filePaths ) {
 538                 global $IP;
 539                 return array_map( function ( $path ) use ( $IP ) {
 540                         return RelPath::joinPath( $IP, $path );
 541                 }, $filePaths );
 542         }
 543
 544         /**
 545          * Get the hash of the message blob.
 546          *
 547          * @since 1.27
 548          * @param ResourceLoaderContext $context
 549          * @return string|null JSON blob or null if module has no messages
 550          */
 551         protected function getMessageBlob( ResourceLoaderContext $context ) {
 552                 if ( !$this->getMessages() ) {
 553                         // Don't bother consulting MessageBlobStore
 554                         return null;
 555                 }
 556                 // Message blobs may only vary language, not by context keys
 557                 $lang = $context->getLanguage();
 558                 if ( !isset( $this->msgBlobs[$lang] ) ) {
 559                         $this->getLogger()->warning( 'Message blob for {module} should have been preloaded', [
 560                                 'module' => $this->getName(),
 561                         ] );
 562                         $store = $context->getResourceLoader()->getMessageBlobStore();
 563                         $this->msgBlobs[$lang] = $store->getBlob( $this, $lang );
 564                 }
 565                 return $this->msgBlobs[$lang];
 566         }
 567
 568         /**
 569          * Set in-object cache for message blobs.
 570          *
 571          * Used to allow fetching of message blobs in batches. See ResourceLoader::preloadModuleInfo().
 572          *
 573          * @since 1.27
 574          * @param string|null $blob JSON blob or null
 575          * @param string $lang Language code
 576          */
 577         public function setMessageBlob( $blob, $lang ) {
 578                 $this->msgBlobs[$lang] = $blob;
 579         }
 580
 581         /**
 582          * Get headers to send as part of a module web response.
 583          *
 584          * It is not supported to send headers through this method that are
 585          * required to be unique or otherwise sent once in an HTTP response
 586          * because clients may make batch requests for multiple modules (as
 587          * is the default behaviour for ResourceLoader clients).
 588          *
 589          * For exclusive or aggregated headers, see ResourceLoader::sendResponseHeaders().
 590          *
 591          * @since 1.30
 592          * @param ResourceLoaderContext $context
 593          * @return string[] Array of HTTP response headers
 594          */
 595         final public function getHeaders( ResourceLoaderContext $context ) {
 596                 $headers = [];
 597
 598                 $formattedLinks = [];
 599                 foreach ( $this->getPreloadLinks( $context ) as $url => $attribs ) {
 600                         $link = "<{$url}>;rel=preload";
 601                         foreach ( $attribs as $key => $val ) {
 602                                 $link .= ";{$key}={$val}";
 603                         }
 604                         $formattedLinks[] = $link;
 605                 }
 606                 if ( $formattedLinks ) {
 607                         $headers[] = 'Link: ' . implode( ',', $formattedLinks );
 608                 }
 609
 610                 return $headers;
 611         }
 612
 613         /**
 614          * Get a list of resources that web browsers may preload.
 615          *
 616          * Behaviour of rel=preload link is specified at <https://www.w3.org/TR/preload/>.
 617          *
 618          * Use case for ResourceLoader originally part of T164299.
 619          *
 620          * @par Example
 621          * @code
 622          *     protected function getPreloadLinks() {
 623          *         return [
 624          *             'https://example.org/script.js' => [ 'as' => 'script' ],
 625          *             'https://example.org/image.png' => [ 'as' => 'image' ],
 626          *         ];
 627          *     }
 628          * @endcode
 629          *
 630          * @par Example using HiDPI image variants
 631          * @code
 632          *     protected function getPreloadLinks() {
 633          *         return [
 634          *             'https://example.org/logo.png' => [
 635          *                 'as' => 'image',
 636          *                 'media' => 'not all and (min-resolution: 2dppx)',
 637          *             ],
 638          *             'https://example.org/logo@2x.png' => [
 639          *                 'as' => 'image',
 640          *                 'media' => '(min-resolution: 2dppx)',
 641          *             ],
 642          *         ];
 643          *     }
 644          * @endcode
 645          *
 646          * @see ResourceLoaderModule::getHeaders
 647          * @since 1.30
 648          * @param ResourceLoaderContext $context
 649          * @return array Keyed by url, values must be an array containing
 650          *  at least an 'as' key. Optionally a 'media' key as well.
 651          */
 652         protected function getPreloadLinks( ResourceLoaderContext $context ) {
 653                 return [];
 654         }
 655
 656         /**
 657          * Get module-specific LESS variables, if any.
 658          *
 659          * @since 1.27
 660          * @param ResourceLoaderContext $context
 661          * @return array Module-specific LESS variables.
 662          */
 663         protected function getLessVars( ResourceLoaderContext $context ) {
 664                 return [];
 665         }
 666
 667         /**
 668          * Get an array of this module's resources. Ready for serving to the web.
 669          *
 670          * @since 1.26
 671          * @param ResourceLoaderContext $context
 672          * @return array
 673          */
 674         public function getModuleContent( ResourceLoaderContext $context ) {
 675                 $contextHash = $context->getHash();
 676                 // Cache this expensive operation. This calls builds the scripts, styles, and messages
 677                 // content which typically involves filesystem and/or database access.
 678                 if ( !array_key_exists( $contextHash, $this->contents ) ) {
 679                         $this->contents[$contextHash] = $this->buildContent( $context );
 680                 }
 681                 return $this->contents[$contextHash];
 682         }
 683
 684         /**
 685          * Bundle all resources attached to this module into an array.
 686          *
 687          * @since 1.26
 688          * @param ResourceLoaderContext $context
 689          * @return array
 690          */
 691         final protected function buildContent( ResourceLoaderContext $context ) {
 692                 $rl = $context->getResourceLoader();
 693                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 694                 $statStart = microtime( true );
 695
 696                 // This MUST build both scripts and styles, regardless of whether $context->getOnly()
 697                 // is 'scripts' or 'styles' because the result is used by getVersionHash which
 698                 // must be consistent regardless of the 'only' filter on the current request.
 699                 // Also, when introducing new module content resources (e.g. templates, headers),
 700                 // these should only be included in the array when they are non-empty so that
 701                 // existing modules not using them do not get their cache invalidated.
 702                 $content = [];
 703
 704                 // Scripts
 705                 // If we are in debug mode, we'll want to return an array of URLs if possible
 706                 // However, we can't do this if the module doesn't support it.
 707                 // We also can't do this if there is an only= parameter, because we have to give
 708                 // the module a way to return a load.php URL without causing an infinite loop
 709                 if ( $context->getDebug() && !$context->getOnly() && $this->supportsURLLoading() ) {
 710                         $scripts = $this->getScriptURLsForDebug( $context );
 711                 } else {
 712                         $scripts = $this->getScript( $context );
 713                         // Make the script safe to concatenate by making sure there is at least one
 714                         // trailing new line at the end of the content. Previously, this looked for
 715                         // a semi-colon instead, but that breaks concatenation if the semicolon
 716                         // is inside a comment like "// foo();". Instead, simply use a
 717                         // line break as separator which matches JavaScript native logic for implicitly
 718                         // ending statements even if a semi-colon is missing.
 719                         // Bugs: T29054, T162719.
 720                         if ( is_string( $scripts )
 721                                 && strlen( $scripts )
 722                                 && substr( $scripts, -1 ) !== "\n"
 723                         ) {
 724                                 $scripts .= "\n";
 725                         }
 726                 }
 727                 $content['scripts'] = $scripts;
 728
 729                 $styles = [];
 730                 // Don't create empty stylesheets like [ '' => '' ] for modules
 731                 // that don't *have* any stylesheets (T40024).
 732                 $stylePairs = $this->getStyles( $context );
 733                 if ( count( $stylePairs ) ) {
 734                         // If we are in debug mode without &only= set, we'll want to return an array of URLs
 735                         // See comment near shouldIncludeScripts() for more details
 736                         if ( $context->getDebug() && !$context->getOnly() && $this->supportsURLLoading() ) {
 737                                 $styles = [
 738                                         'url' => $this->getStyleURLsForDebug( $context )
 739                                 ];
 740                         } else {
 741                                 // Minify CSS before embedding in mw.loader.implement call
 742                                 // (unless in debug mode)
 743                                 if ( !$context->getDebug() ) {
 744                                         foreach ( $stylePairs as $media => $style ) {
 745                                                 // Can be either a string or an array of strings.
 746                                                 if ( is_array( $style ) ) {
 747                                                         $stylePairs[$media] = [];
 748                                                         foreach ( $style as $cssText ) {
 749                                                                 if ( is_string( $cssText ) ) {
 750                                                                         $stylePairs[$media][] =
 751                                                                                 ResourceLoader::filter( 'minify-css', $cssText );
 752                                                                 }
 753                                                         }
 754                                                 } elseif ( is_string( $style ) ) {
 755                                                         $stylePairs[$media] = ResourceLoader::filter( 'minify-css', $style );
 756                                                 }
 757                                         }
 758                                 }
 759                                 // Wrap styles into @media groups as needed and flatten into a numerical array
 760                                 $styles = [
 761                                         'css' => $rl->makeCombinedStyles( $stylePairs )
 762                                 ];
 763                         }
 764                 }
 765                 $content['styles'] = $styles;
 766
 767                 // Messages
 768                 $blob = $this->getMessageBlob( $context );
 769                 if ( $blob ) {
 770                         $content['messagesBlob'] = $blob;
 771                 }
 772
 773                 $templates = $this->getTemplates();
 774                 if ( $templates ) {
 775                         $content['templates'] = $templates;
 776                 }
 777
 778                 $headers = $this->getHeaders( $context );
 779                 if ( $headers ) {
 780                         $content['headers'] = $headers;
 781                 }
 782
 783                 $statTiming = microtime( true ) - $statStart;
 784                 $statName = strtr( $this->getName(), '.', '_' );
 785                 $stats->timing( "resourceloader_build.all", 1000 * $statTiming );
 786                 $stats->timing( "resourceloader_build.$statName", 1000 * $statTiming );
 787
 788                 return $content;
 789         }
 790
 791         /**
 792          * Get a string identifying the current version of this module in a given context.
 793          *
 794          * Whenever anything happens that changes the module's response (e.g. scripts, styles, and
 795          * messages) this value must change. This value is used to store module responses in cache.
 796          * (Both client-side and server-side.)
 797          *
 798          * It is not recommended to override this directly. Use getDefinitionSummary() instead.
 799          * If overridden, one must call the parent getVersionHash(), append data and re-hash.
 800          *
 801          * This method should be quick because it is frequently run by ResourceLoaderStartUpModule to
 802          * propagate changes to the client and effectively invalidate cache.
 803          *
 804          * @since 1.26
 805          * @param ResourceLoaderContext $context
 806          * @return string Hash (should use ResourceLoader::makeHash)
 807          */
 808         public function getVersionHash( ResourceLoaderContext $context ) {
 809                 // Cache this somewhat expensive operation. Especially because some classes
 810                 // (e.g. startup module) iterate more than once over all modules to get versions.
 811                 $contextHash = $context->getHash();
 812                 if ( !array_key_exists( $contextHash, $this->versionHash ) ) {
 813                         if ( $this->enableModuleContentVersion() ) {
 814                                 // Detect changes directly by hashing the module contents.
 815                                 $str = json_encode( $this->getModuleContent( $context ) );
 816                         } else {
 817                                 // Infer changes based on definition and other metrics
 818                                 $summary = $this->getDefinitionSummary( $context );
 819                                 if ( !isset( $summary['_class'] ) ) {
 820                                         throw new LogicException( 'getDefinitionSummary must call parent method' );
 821                                 }
 822                                 $str = json_encode( $summary );
 823                         }
 824
 825                         $this->versionHash[$contextHash] = ResourceLoader::makeHash( $str );
 826                 }
 827                 return $this->versionHash[$contextHash];
 828         }
 829
 830         /**
 831          * Whether to generate version hash based on module content.
 832          *
 833          * If a module requires database or file system access to build the module
 834          * content, consider disabling this in favour of manually tracking relevant
 835          * aspects in getDefinitionSummary(). See getVersionHash() for how this is used.
 836          *
 837          * @return bool
 838          */
 839         public function enableModuleContentVersion() {
 840                 return false;
 841         }
 842
 843         /**
 844          * Get the definition summary for this module.
 845          *
 846          * This is the method subclasses are recommended to use to track values in their
 847          * version hash. Call this in getVersionHash() and pass it to e.g. json_encode.
 848          *
 849          * Subclasses must call the parent getDefinitionSummary() and build on that.
 850          * It is recommended that each subclass appends its own new array. This prevents
 851          * clashes or accidental overwrites of existing keys and gives each subclass
 852          * its own scope for simple array keys.
 853          *
 854          * @code
 855          *     $summary = parent::getDefinitionSummary( $context );
 856          *     $summary[] = [
 857          *         'foo' => 123,
 858          *         'bar' => 'quux',
 859          *     ];
 860          *     return $summary;
 861          * @endcode
 862          *
 863          * Return an array containing values from all significant properties of this
 864          * module's definition.
 865          *
 866          * Be careful not to normalise too much. Especially preserve the order of things
 867          * that carry significance in getScript and getStyles (T39812).
 868          *
 869          * Avoid including things that are insiginificant (e.g. order of message keys is
 870          * insignificant and should be sorted to avoid unnecessary cache invalidation).
 871          *
 872          * This data structure must exclusively contain arrays and scalars as values (avoid
 873          * object instances) to allow simple serialisation using json_encode.
 874          *
 875          * If modules have a hash or timestamp from another source, that may be incuded as-is.
 876          *
 877          * A number of utility methods are available to help you gather data. These are not
 878          * called by default and must be included by the subclass' getDefinitionSummary().
 879          *
 880          * - getMessageBlob()
 881          *
 882          * @since 1.23
 883          * @param ResourceLoaderContext $context
 884          * @return array|null
 885          */
 886         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 887                 return [
 888                         '_class' => static::class,
 889                         // Make sure that when filter cache for minification is invalidated,
 890                         // we also change the HTTP urls and mw.loader.store keys (T176884).
 891                         '_cacheVersion' => ResourceLoader::CACHE_VERSION,
 892                 ];
 893         }
 894
 895         /**
 896          * Check whether this module is known to be empty. If a child class
 897          * has an easy and cheap way to determine that this module is
 898          * definitely going to be empty, it should override this method to
 899          * return true in that case. Callers may optimize the request for this
 900          * module away if this function returns true.
 901          * @param ResourceLoaderContext $context
 902          * @return bool
 903          */
 904         public function isKnownEmpty( ResourceLoaderContext $context ) {
 905                 return false;
 906         }
 907
 908         /**
 909          * Check whether this module should be embeded rather than linked
 910          *
 911          * Modules returning true here will be embedded rather than loaded by
 912          * ResourceLoaderClientHtml.
 913          *
 914          * @since 1.30
 915          * @param ResourceLoaderContext $context
 916          * @return bool
 917          */
 918         public function shouldEmbedModule( ResourceLoaderContext $context ) {
 919                 return $this->getGroup() === 'private';
 920         }
 921
 922         /** @var JSParser Lazy-initialized; use self::javaScriptParser() */
 923         private static $jsParser;
 924         private static $parseCacheVersion = 1;
 925
 926         /**
 927          * Validate a given script file; if valid returns the original source.
 928          * If invalid, returns replacement JS source that throws an exception.
 929          *
 930          * @param string $fileName
 931          * @param string $contents
 932          * @return string JS with the original, or a replacement error
 933          */
 934         protected function validateScriptFile( $fileName, $contents ) {
 935                 if ( !$this->getConfig()->get( 'ResourceLoaderValidateJS' ) ) {
 936                         return $contents;
 937                 }
 938                 $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
 939                 return $cache->getWithSetCallback(
 940                         $cache->makeGlobalKey(
 941                                 'resourceloader-jsparse',
 942                                 self::$parseCacheVersion,
 943                                 md5( $contents ),
 944                                 $fileName
 945                         ),
 946                         $cache::TTL_WEEK,
 947                         function () use ( $contents, $fileName ) {
 948                                 $parser = self::javaScriptParser();
 949                                 $err = null;
 950                                 try {
 951                                         AtEase::suppressWarnings();
 952                                         $parser->parse( $contents, $fileName, 1 );
 953                                 } catch ( Exception $e ) {
 954                                         $err = $e;
 955                                 } finally {
 956                                         AtEase::restoreWarnings();
 957                                 }
 958                                 if ( $err ) {
 959                                         // Send the error to the browser console client-side.
 960                                         // By returning this as replacement for the actual script,
 961                                         // we ensure modules are safe to load in a batch request,
 962                                         // without causing other unrelated modules to break.
 963                                         return 'mw.log.error(' .
 964                                                 Xml::encodeJsVar( 'JavaScript parse error: ' . $err->getMessage() ) .
 965                                                 ');';
 966                                 }
 967                                 return $contents;
 968                         }
 969                 );
 970         }
 971
 972         /**
 973          * @return JSParser
 974          */
 975         protected static function javaScriptParser() {
 976                 if ( !self::$jsParser ) {
 977                         self::$jsParser = new JSParser();
 978                 }
 979                 return self::$jsParser;
 980         }
 981
 982         /**
 983          * Safe version of filemtime(), which doesn't throw a PHP warning if the file doesn't exist.
 984          * Defaults to 1.
 985          *
 986          * @param string $filePath File path
 987          * @return int UNIX timestamp
 988          */
 989         protected static function safeFilemtime( $filePath ) {
 990                 AtEase::suppressWarnings();
 991                 $mtime = filemtime( $filePath ) ?: 1;
 992                 AtEase::restoreWarnings();
 993                 return $mtime;
 994         }
 995
 996         /**
 997          * Compute a non-cryptographic string hash of a file's contents.
 998          * If the file does not exist or cannot be read, returns an empty string.
 999          *
1000          * @since 1.26 Uses MD4 instead of SHA1.
1001          * @param string $filePath File path
1002          * @return string Hash
1003          */
1004         protected static function safeFileHash( $filePath ) {
1005                 return FileContentsHasher::getFileContentsHash( $filePath );
1006         }
1007
1008         /**
1009          * Get vary string.
1010          *
1011          * @internal For internal use only.
1012          * @param ResourceLoaderContext $context
1013          * @return string Vary string
1014          */
1015         public static function getVary( ResourceLoaderContext $context ) {
1016                 return implode( '|', [
1017                         $context->getSkin(),
1018                         $context->getLanguage(),
1019                 ] );
1020         }
1021 }