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\RelPath;
  30 use Wikimedia\ScopedCallback;
  31
  32 /**
  33  * Abstraction for ResourceLoader modules, with name registration and maxage functionality.
  34  */
  35 abstract class ResourceLoaderModule implements LoggerAwareInterface {
  36         # Type of resource
  37         const TYPE_SCRIPTS = 'scripts';
  38         const TYPE_STYLES = 'styles';
  39         const TYPE_COMBINED = 'combined';
  40
  41         # Desired load type
  42         // Module only has styles (loaded via <style> or <link rel=stylesheet>)
  43         const LOAD_STYLES = 'styles';
  44         // Module may have other resources (loaded via mw.loader from a script)
  45         const LOAD_GENERAL = 'general';
  46
  47         # sitewide core module like a skin file or jQuery component
  48         const ORIGIN_CORE_SITEWIDE = 1;
  49
  50         # per-user module generated by the software
  51         const ORIGIN_CORE_INDIVIDUAL = 2;
  52
  53         # sitewide module generated from user-editable files, like MediaWiki:Common.js, or
  54         # modules accessible to multiple users, such as those generated by the Gadgets extension.
  55         const ORIGIN_USER_SITEWIDE = 3;
  56
  57         # per-user module generated from user-editable files, like User:Me/vector.js
  58         const ORIGIN_USER_INDIVIDUAL = 4;
  59
  60         # an access constant; make sure this is kept as the largest number in this group
  61         const ORIGIN_ALL = 10;
  62
  63         # script and style modules form a hierarchy of trustworthiness, with core modules like
  64         # skins and jQuery as most trustworthy, and user scripts as least trustworthy.  We can
  65         # limit the types of scripts and styles we allow to load on, say, sensitive special
  66         # pages like Special:UserLogin and Special:Preferences
  67         protected $origin = self::ORIGIN_CORE_SITEWIDE;
  68
  69         protected $name = null;
  70         protected $targets = [ 'desktop' ];
  71
  72         // In-object cache for file dependencies
  73         protected $fileDeps = [];
  74         // In-object cache for message blob (keyed by language)
  75         protected $msgBlobs = [];
  76         // In-object cache for version hash
  77         protected $versionHash = [];
  78         // In-object cache for module content
  79         protected $contents = [];
  80
  81         /**
  82          * @var Config
  83          */
  84         protected $config;
  85
  86         /**
  87          * @var array|bool
  88          */
  89         protected $deprecated = false;
  90
  91         /**
  92          * @var LoggerInterface
  93          */
  94         protected $logger;
  95
  96         /**
  97          * Get this module's name. This is set when the module is registered
  98          * with ResourceLoader::register()
  99          *
 100          * @return string|null Name (string) or null if no name was set
 101          */
 102         public function getName() {
 103                 return $this->name;
 104         }
 105
 106         /**
 107          * Set this module's name. This is called by ResourceLoader::register()
 108          * when registering the module. Other code should not call this.
 109          *
 110          * @param string $name
 111          */
 112         public function setName( $name ) {
 113                 $this->name = $name;
 114         }
 115
 116         /**
 117          * Get this module's origin. This is set when the module is registered
 118          * with ResourceLoader::register()
 119          *
 120          * @return int ResourceLoaderModule class constant, the subclass default
 121          *     if not set manually
 122          */
 123         public function getOrigin() {
 124                 return $this->origin;
 125         }
 126
 127         /**
 128          * @param ResourceLoaderContext $context
 129          * @return bool
 130          */
 131         public function getFlip( $context ) {
 132                 global $wgContLang;
 133
 134                 return $wgContLang->getDir() !== $context->getDirection();
 135         }
 136
 137         /**
 138          * Get JS representing deprecation information for the current module if available
 139          *
 140          * @return string JavaScript code
 141          */
 142         protected function getDeprecationInformation() {
 143                 $deprecationInfo = $this->deprecated;
 144                 if ( $deprecationInfo ) {
 145                         $name = $this->getName();
 146                         $warning = 'This page is using the deprecated ResourceLoader module "' . $name . '".';
 147                         if ( is_string( $deprecationInfo ) ) {
 148                                 $warning .= "\n" . $deprecationInfo;
 149                         }
 150                         return Xml::encodeJsCall(
 151                                 'mw.log.warn',
 152                                 [ $warning ]
 153                         );
 154                 } else {
 155                         return '';
 156                 }
 157         }
 158
 159         /**
 160          * Get all JS for this module for a given language and skin.
 161          * Includes all relevant JS except loader scripts.
 162          *
 163          * @param ResourceLoaderContext $context
 164          * @return string JavaScript code
 165          */
 166         public function getScript( ResourceLoaderContext $context ) {
 167                 // Stub, override expected
 168                 return '';
 169         }
 170
 171         /**
 172          * Takes named templates by the module and returns an array mapping.
 173          *
 174          * @return array of templates mapping template alias to content
 175          */
 176         public function getTemplates() {
 177                 // Stub, override expected.
 178                 return [];
 179         }
 180
 181         /**
 182          * @return Config
 183          * @since 1.24
 184          */
 185         public function getConfig() {
 186                 if ( $this->config === null ) {
 187                         // Ugh, fall back to default
 188                         $this->config = MediaWikiServices::getInstance()->getMainConfig();
 189                 }
 190
 191                 return $this->config;
 192         }
 193
 194         /**
 195          * @param Config $config
 196          * @since 1.24
 197          */
 198         public function setConfig( Config $config ) {
 199                 $this->config = $config;
 200         }
 201
 202         /**
 203          * @since 1.27
 204          * @param LoggerInterface $logger
 205          * @return null
 206          */
 207         public function setLogger( LoggerInterface $logger ) {
 208                 $this->logger = $logger;
 209         }
 210
 211         /**
 212          * @since 1.27
 213          * @return LoggerInterface
 214          */
 215         protected function getLogger() {
 216                 if ( !$this->logger ) {
 217                         $this->logger = new NullLogger();
 218                 }
 219                 return $this->logger;
 220         }
 221
 222         /**
 223          * Get the URL or URLs to load for this module's JS in debug mode.
 224          * The default behavior is to return a load.php?only=scripts URL for
 225          * the module, but file-based modules will want to override this to
 226          * load the files directly.
 227          *
 228          * This function is called only when 1) we're in debug mode, 2) there
 229          * is no only= parameter and 3) supportsURLLoading() returns true.
 230          * #2 is important to prevent an infinite loop, therefore this function
 231          * MUST return either an only= URL or a non-load.php URL.
 232          *
 233          * @param ResourceLoaderContext $context
 234          * @return array Array of URLs
 235          */
 236         public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
 237                 $resourceLoader = $context->getResourceLoader();
 238                 $derivative = new DerivativeResourceLoaderContext( $context );
 239                 $derivative->setModules( [ $this->getName() ] );
 240                 $derivative->setOnly( 'scripts' );
 241                 $derivative->setDebug( true );
 242
 243                 $url = $resourceLoader->createLoaderURL(
 244                         $this->getSource(),
 245                         $derivative
 246                 );
 247
 248                 return [ $url ];
 249         }
 250
 251         /**
 252          * Whether this module supports URL loading. If this function returns false,
 253          * getScript() will be used even in cases (debug mode, no only param) where
 254          * getScriptURLsForDebug() would normally be used instead.
 255          * @return bool
 256          */
 257         public function supportsURLLoading() {
 258                 return true;
 259         }
 260
 261         /**
 262          * Get all CSS for this module for a given skin.
 263          *
 264          * @param ResourceLoaderContext $context
 265          * @return array List of CSS strings or array of CSS strings keyed by media type.
 266          *  like [ 'screen' => '.foo { width: 0 }' ];
 267          *  or [ 'screen' => [ '.foo { width: 0 }' ] ];
 268          */
 269         public function getStyles( ResourceLoaderContext $context ) {
 270                 // Stub, override expected
 271                 return [];
 272         }
 273
 274         /**
 275          * Get the URL or URLs to load for this module's CSS in debug mode.
 276          * The default behavior is to return a load.php?only=styles URL for
 277          * the module, but file-based modules will want to override this to
 278          * load the files directly. See also getScriptURLsForDebug()
 279          *
 280          * @param ResourceLoaderContext $context
 281          * @return array [ mediaType => [ URL1, URL2, ... ], ... ]
 282          */
 283         public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
 284                 $resourceLoader = $context->getResourceLoader();
 285                 $derivative = new DerivativeResourceLoaderContext( $context );
 286                 $derivative->setModules( [ $this->getName() ] );
 287                 $derivative->setOnly( 'styles' );
 288                 $derivative->setDebug( true );
 289
 290                 $url = $resourceLoader->createLoaderURL(
 291                         $this->getSource(),
 292                         $derivative
 293                 );
 294
 295                 return [ 'all' => [ $url ] ];
 296         }
 297
 298         /**
 299          * Get the messages needed for this module.
 300          *
 301          * To get a JSON blob with messages, use MessageBlobStore::get()
 302          *
 303          * @return array List of message keys. Keys may occur more than once
 304          */
 305         public function getMessages() {
 306                 // Stub, override expected
 307                 return [];
 308         }
 309
 310         /**
 311          * Get the group this module is in.
 312          *
 313          * @return string Group name
 314          */
 315         public function getGroup() {
 316                 // Stub, override expected
 317                 return null;
 318         }
 319
 320         /**
 321          * Get the origin of this module. Should only be overridden for foreign modules.
 322          *
 323          * @return string Origin name, 'local' for local modules
 324          */
 325         public function getSource() {
 326                 // Stub, override expected
 327                 return 'local';
 328         }
 329
 330         /**
 331          * From where in the page HTML should this module be loaded?
 332          *
 333          * @deprecated since 1.29 Obsolete. All modules load async from `<head>`.
 334          * @return string
 335          */
 336         public function getPosition() {
 337                 return 'top';
 338         }
 339
 340         /**
 341          * Whether this module's JS expects to work without the client-side ResourceLoader module.
 342          * Returning true from this function will prevent mw.loader.state() call from being
 343          * appended to the bottom of the script.
 344          *
 345          * @return bool
 346          */
 347         public function isRaw() {
 348                 return false;
 349         }
 350
 351         /**
 352          * Get a list of modules this module depends on.
 353          *
 354          * Dependency information is taken into account when loading a module
 355          * on the client side.
 356          *
 357          * Note: It is expected that $context will be made non-optional in the near
 358          * future.
 359          *
 360          * @param ResourceLoaderContext $context
 361          * @return array List of module names as strings
 362          */
 363         public function getDependencies( ResourceLoaderContext $context = null ) {
 364                 // Stub, override expected
 365                 return [];
 366         }
 367
 368         /**
 369          * Get target(s) for the module, eg ['desktop'] or ['desktop', 'mobile']
 370          *
 371          * @return array Array of strings
 372          */
 373         public function getTargets() {
 374                 return $this->targets;
 375         }
 376
 377         /**
 378          * Get the module's load type.
 379          *
 380          * @since 1.28
 381          * @return string ResourceLoaderModule LOAD_* constant
 382          */
 383         public function getType() {
 384                 return self::LOAD_GENERAL;
 385         }
 386
 387         /**
 388          * Get the skip function.
 389          *
 390          * Modules that provide fallback functionality can provide a "skip function". This
 391          * function, if provided, will be passed along to the module registry on the client.
 392          * When this module is loaded (either directly or as a dependency of another module),
 393          * then this function is executed first. If the function returns true, the module will
 394          * instantly be considered "ready" without requesting the associated module resources.
 395          *
 396          * The value returned here must be valid javascript for execution in a private function.
 397          * It must not contain the "function () {" and "}" wrapper though.
 398          *
 399          * @return string|null A JavaScript function body returning a boolean value, or null
 400          */
 401         public function getSkipFunction() {
 402                 return null;
 403         }
 404
 405         /**
 406          * Get the files this module depends on indirectly for a given skin.
 407          *
 408          * These are only image files referenced by the module's stylesheet.
 409          *
 410          * @param ResourceLoaderContext $context
 411          * @return array List of files
 412          */
 413         protected function getFileDependencies( ResourceLoaderContext $context ) {
 414                 $vary = $context->getSkin() . '|' . $context->getLanguage();
 415
 416                 // Try in-object cache first
 417                 if ( !isset( $this->fileDeps[$vary] ) ) {
 418                         $dbr = wfGetDB( DB_REPLICA );
 419                         $deps = $dbr->selectField( 'module_deps',
 420                                 'md_deps',
 421                                 [
 422                                         'md_module' => $this->getName(),
 423                                         'md_skin' => $vary,
 424                                 ],
 425                                 __METHOD__
 426                         );
 427
 428                         if ( !is_null( $deps ) ) {
 429                                 $this->fileDeps[$vary] = self::expandRelativePaths(
 430                                         (array)FormatJson::decode( $deps, true )
 431                                 );
 432                         } else {
 433                                 $this->fileDeps[$vary] = [];
 434                         }
 435                 }
 436                 return $this->fileDeps[$vary];
 437         }
 438
 439         /**
 440          * Set in-object cache for file dependencies.
 441          *
 442          * This is used to retrieve data in batches. See ResourceLoader::preloadModuleInfo().
 443          * To save the data, use saveFileDependencies().
 444          *
 445          * @param ResourceLoaderContext $context
 446          * @param string[] $files Array of file names
 447          */
 448         public function setFileDependencies( ResourceLoaderContext $context, $files ) {
 449                 $vary = $context->getSkin() . '|' . $context->getLanguage();
 450                 $this->fileDeps[$vary] = $files;
 451         }
 452
 453         /**
 454          * Set the files this module depends on indirectly for a given skin.
 455          *
 456          * @since 1.27
 457          * @param ResourceLoaderContext $context
 458          * @param array $localFileRefs List of files
 459          */
 460         protected function saveFileDependencies( ResourceLoaderContext $context, $localFileRefs ) {
 461                 try {
 462                         // Related bugs and performance considerations:
 463                         // 1. Don't needlessly change the database value with the same list in a
 464                         //    different order or with duplicates.
 465                         // 2. Use relative paths to avoid ghost entries when $IP changes. (T111481)
 466                         // 3. Don't needlessly replace the database with the same value
 467                         //    just because $IP changed (e.g. when upgrading a wiki).
 468                         // 4. Don't create an endless replace loop on every request for this
 469                         //    module when '../' is used anywhere. Even though both are expanded
 470                         //    (one expanded by getFileDependencies from the DB, the other is
 471                         //    still raw as originally read by RL), the latter has not
 472                         //    been normalized yet.
 473
 474                         // Normalise
 475                         $localFileRefs = array_values( array_unique( $localFileRefs ) );
 476                         sort( $localFileRefs );
 477                         $localPaths = self::getRelativePaths( $localFileRefs );
 478
 479                         $storedPaths = self::getRelativePaths( $this->getFileDependencies( $context ) );
 480                         // If the list has been modified since last time we cached it, update the cache
 481                         if ( $localPaths !== $storedPaths ) {
 482                                 $vary = $context->getSkin() . '|' . $context->getLanguage();
 483                                 $cache = ObjectCache::getLocalClusterInstance();
 484                                 $key = $cache->makeKey( __METHOD__, $this->getName(), $vary );
 485                                 $scopeLock = $cache->getScopedLock( $key, 0 );
 486                                 if ( !$scopeLock ) {
 487                                         return; // T124649; avoid write slams
 488                                 }
 489
 490                                 $deps = FormatJson::encode( $localPaths );
 491                                 $dbw = wfGetDB( DB_MASTER );
 492                                 $dbw->upsert( 'module_deps',
 493                                         [
 494                                                 'md_module' => $this->getName(),
 495                                                 'md_skin' => $vary,
 496                                                 'md_deps' => $deps,
 497                                         ],
 498                                         [ 'md_module', 'md_skin' ],
 499                                         [
 500                                                 'md_deps' => $deps,
 501                                         ]
 502                                 );
 503
 504                                 if ( $dbw->trxLevel() ) {
 505                                         $dbw->onTransactionResolution(
 506                                                 function () use ( &$scopeLock ) {
 507                                                         ScopedCallback::consume( $scopeLock ); // release after commit
 508                                                 },
 509                                                 __METHOD__
 510                                         );
 511                                 }
 512                         }
 513                 } catch ( Exception $e ) {
 514                         wfDebugLog( 'resourceloader', __METHOD__ . ": failed to update DB: $e" );
 515                 }
 516         }
 517
 518         /**
 519          * Make file paths relative to MediaWiki directory.
 520          *
 521          * This is used to make file paths safe for storing in a database without the paths
 522          * becoming stale or incorrect when MediaWiki is moved or upgraded (T111481).
 523          *
 524          * @since 1.27
 525          * @param array $filePaths
 526          * @return array
 527          */
 528         public static function getRelativePaths( array $filePaths ) {
 529                 global $IP;
 530                 return array_map( function ( $path ) use ( $IP ) {
 531                         return RelPath::getRelativePath( $path, $IP );
 532                 }, $filePaths );
 533         }
 534
 535         /**
 536          * Expand directories relative to $IP.
 537          *
 538          * @since 1.27
 539          * @param array $filePaths
 540          * @return array
 541          */
 542         public static function expandRelativePaths( array $filePaths ) {
 543                 global $IP;
 544                 return array_map( function ( $path ) use ( $IP ) {
 545                         return RelPath::joinPath( $IP, $path );
 546                 }, $filePaths );
 547         }
 548
 549         /**
 550          * Get the hash of the message blob.
 551          *
 552          * @since 1.27
 553          * @param ResourceLoaderContext $context
 554          * @return string|null JSON blob or null if module has no messages
 555          */
 556         protected function getMessageBlob( ResourceLoaderContext $context ) {
 557                 if ( !$this->getMessages() ) {
 558                         // Don't bother consulting MessageBlobStore
 559                         return null;
 560                 }
 561                 // Message blobs may only vary language, not by context keys
 562                 $lang = $context->getLanguage();
 563                 if ( !isset( $this->msgBlobs[$lang] ) ) {
 564                         $this->getLogger()->warning( 'Message blob for {module} should have been preloaded', [
 565                                 'module' => $this->getName(),
 566                         ] );
 567                         $store = $context->getResourceLoader()->getMessageBlobStore();
 568                         $this->msgBlobs[$lang] = $store->getBlob( $this, $lang );
 569                 }
 570                 return $this->msgBlobs[$lang];
 571         }
 572
 573         /**
 574          * Set in-object cache for message blobs.
 575          *
 576          * Used to allow fetching of message blobs in batches. See ResourceLoader::preloadModuleInfo().
 577          *
 578          * @since 1.27
 579          * @param string|null $blob JSON blob or null
 580          * @param string $lang Language code
 581          */
 582         public function setMessageBlob( $blob, $lang ) {
 583                 $this->msgBlobs[$lang] = $blob;
 584         }
 585
 586         /**
 587          * Get headers to send as part of a module web response.
 588          *
 589          * It is not supported to send headers through this method that are
 590          * required to be unique or otherwise sent once in an HTTP response
 591          * because clients may make batch requests for multiple modules (as
 592          * is the default behaviour for ResourceLoader clients).
 593          *
 594          * For exclusive or aggregated headers, see ResourceLoader::sendResponseHeaders().
 595          *
 596          * @since 1.30
 597          * @param ResourceLoaderContext $context
 598          * @return string[] Array of HTTP response headers
 599          */
 600         final public function getHeaders( ResourceLoaderContext $context ) {
 601                 $headers = [];
 602
 603                 $formattedLinks = [];
 604                 foreach ( $this->getPreloadLinks( $context ) as $url => $attribs ) {
 605                         $link = "<{$url}>;rel=preload";
 606                         foreach ( $attribs as $key => $val ) {
 607                                 $link .= ";{$key}={$val}";
 608                         }
 609                         $formattedLinks[] = $link;
 610                 }
 611                 if ( $formattedLinks ) {
 612                         $headers[] = 'Link: ' . implode( ',', $formattedLinks );
 613                 }
 614
 615                 return $headers;
 616         }
 617
 618         /**
 619          * Get a list of resources that web browsers may preload.
 620          *
 621          * Behaviour of rel=preload link is specified at <https://www.w3.org/TR/preload/>.
 622          *
 623          * Use case for ResourceLoader originally part of T164299.
 624          *
 625          * @par Example
 626          * @code
 627          *     protected function getPreloadLinks() {
 628          *         return [
 629          *             'https://example.org/script.js' => [ 'as' => 'script' ],
 630          *             'https://example.org/image.png' => [ 'as' => 'image' ],
 631          *         ];
 632          *     }
 633          * @encode
 634          *
 635          * @par Example using HiDPI image variants
 636          * @code
 637          *     protected function getPreloadLinks() {
 638          *         return [
 639          *             'https://example.org/logo.png' => [
 640          *                 'as' => 'image',
 641          *                 'media' => 'not all and (min-resolution: 2dppx)',
 642          *             ],
 643          *             'https://example.org/logo@2x.png' => [
 644          *                 'as' => 'image',
 645          *                 'media' => '(min-resolution: 2dppx)',
 646          *             ],
 647          *         ];
 648          *     }
 649          * @encode
 650          *
 651          * @see ResourceLoaderModule::getHeaders
 652          * @since 1.30
 653          * @param ResourceLoaderContext $context
 654          * @return array Keyed by url, values must be an array containing
 655          *  at least an 'as' key. Optionally a 'media' key as well.
 656          */
 657         protected function getPreloadLinks( ResourceLoaderContext $context ) {
 658                 return [];
 659         }
 660
 661         /**
 662          * Get module-specific LESS variables, if any.
 663          *
 664          * @since 1.27
 665          * @param ResourceLoaderContext $context
 666          * @return array Module-specific LESS variables.
 667          */
 668         protected function getLessVars( ResourceLoaderContext $context ) {
 669                 return [];
 670         }
 671
 672         /**
 673          * Get an array of this module's resources. Ready for serving to the web.
 674          *
 675          * @since 1.26
 676          * @param ResourceLoaderContext $context
 677          * @return array
 678          */
 679         public function getModuleContent( ResourceLoaderContext $context ) {
 680                 $contextHash = $context->getHash();
 681                 // Cache this expensive operation. This calls builds the scripts, styles, and messages
 682                 // content which typically involves filesystem and/or database access.
 683                 if ( !array_key_exists( $contextHash, $this->contents ) ) {
 684                         $this->contents[$contextHash] = $this->buildContent( $context );
 685                 }
 686                 return $this->contents[$contextHash];
 687         }
 688
 689         /**
 690          * Bundle all resources attached to this module into an array.
 691          *
 692          * @since 1.26
 693          * @param ResourceLoaderContext $context
 694          * @return array
 695          */
 696         final protected function buildContent( ResourceLoaderContext $context ) {
 697                 $rl = $context->getResourceLoader();
 698                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 699                 $statStart = microtime( true );
 700
 701                 // Only include properties that are relevant to this context (e.g. only=scripts)
 702                 // and that are non-empty (e.g. don't include "templates" for modules without
 703                 // templates). This helps prevent invalidating cache for all modules when new
 704                 // optional properties are introduced.
 705                 $content = [];
 706
 707                 // Scripts
 708                 if ( $context->shouldIncludeScripts() ) {
 709                         // If we are in debug mode, we'll want to return an array of URLs if possible
 710                         // However, we can't do this if the module doesn't support it
 711                         // We also can't do this if there is an only= parameter, because we have to give
 712                         // the module a way to return a load.php URL without causing an infinite loop
 713                         if ( $context->getDebug() && !$context->getOnly() && $this->supportsURLLoading() ) {
 714                                 $scripts = $this->getScriptURLsForDebug( $context );
 715                         } else {
 716                                 $scripts = $this->getScript( $context );
 717                                 // Make the script safe to concatenate by making sure there is at least one
 718                                 // trailing new line at the end of the content. Previously, this looked for
 719                                 // a semi-colon instead, but that breaks concatenation if the semicolon
 720                                 // is inside a comment like "// foo();". Instead, simply use a
 721                                 // line break as separator which matches JavaScript native logic for implicitly
 722                                 // ending statements even if a semi-colon is missing.
 723                                 // Bugs: T29054, T162719.
 724                                 if ( is_string( $scripts )
 725                                         && strlen( $scripts )
 726                                         && substr( $scripts, -1 ) !== "\n"
 727                                 ) {
 728                                         $scripts .= "\n";
 729                                 }
 730                         }
 731                         $content['scripts'] = $scripts;
 732                 }
 733
 734                 // Styles
 735                 if ( $context->shouldIncludeStyles() ) {
 736                         $styles = [];
 737                         // Don't create empty stylesheets like [ '' => '' ] for modules
 738                         // that don't *have* any stylesheets (T40024).
 739                         $stylePairs = $this->getStyles( $context );
 740                         if ( count( $stylePairs ) ) {
 741                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 742                                 // See comment near shouldIncludeScripts() for more details
 743                                 if ( $context->getDebug() && !$context->getOnly() && $this->supportsURLLoading() ) {
 744                                         $styles = [
 745                                                 'url' => $this->getStyleURLsForDebug( $context )
 746                                         ];
 747                                 } else {
 748                                         // Minify CSS before embedding in mw.loader.implement call
 749                                         // (unless in debug mode)
 750                                         if ( !$context->getDebug() ) {
 751                                                 foreach ( $stylePairs as $media => $style ) {
 752                                                         // Can be either a string or an array of strings.
 753                                                         if ( is_array( $style ) ) {
 754                                                                 $stylePairs[$media] = [];
 755                                                                 foreach ( $style as $cssText ) {
 756                                                                         if ( is_string( $cssText ) ) {
 757                                                                                 $stylePairs[$media][] =
 758                                                                                         ResourceLoader::filter( 'minify-css', $cssText );
 759                                                                         }
 760                                                                 }
 761                                                         } elseif ( is_string( $style ) ) {
 762                                                                 $stylePairs[$media] = ResourceLoader::filter( 'minify-css', $style );
 763                                                         }
 764                                                 }
 765                                         }
 766                                         // Wrap styles into @media groups as needed and flatten into a numerical array
 767                                         $styles = [
 768                                                 'css' => $rl->makeCombinedStyles( $stylePairs )
 769                                         ];
 770                                 }
 771                         }
 772                         $content['styles'] = $styles;
 773                 }
 774
 775                 // Messages
 776                 $blob = $this->getMessageBlob( $context );
 777                 if ( $blob ) {
 778                         $content['messagesBlob'] = $blob;
 779                 }
 780
 781                 $templates = $this->getTemplates();
 782                 if ( $templates ) {
 783                         $content['templates'] = $templates;
 784                 }
 785
 786                 $headers = $this->getHeaders( $context );
 787                 if ( $headers ) {
 788                         $content['headers'] = $headers;
 789                 }
 790
 791                 $statTiming = microtime( true ) - $statStart;
 792                 $statName = strtr( $this->getName(), '.', '_' );
 793                 $stats->timing( "resourceloader_build.all", 1000 * $statTiming );
 794                 $stats->timing( "resourceloader_build.$statName", 1000 * $statTiming );
 795
 796                 return $content;
 797         }
 798
 799         /**
 800          * Get a string identifying the current version of this module in a given context.
 801          *
 802          * Whenever anything happens that changes the module's response (e.g. scripts, styles, and
 803          * messages) this value must change. This value is used to store module responses in cache.
 804          * (Both client-side and server-side.)
 805          *
 806          * It is not recommended to override this directly. Use getDefinitionSummary() instead.
 807          * If overridden, one must call the parent getVersionHash(), append data and re-hash.
 808          *
 809          * This method should be quick because it is frequently run by ResourceLoaderStartUpModule to
 810          * propagate changes to the client and effectively invalidate cache.
 811          *
 812          * For backward-compatibility, the following optional data providers are automatically included:
 813          *
 814          * - getModifiedTime()
 815          * - getModifiedHash()
 816          *
 817          * @since 1.26
 818          * @param ResourceLoaderContext $context
 819          * @return string Hash (should use ResourceLoader::makeHash)
 820          */
 821         public function getVersionHash( ResourceLoaderContext $context ) {
 822                 // The startup module produces a manifest with versions representing the entire module.
 823                 // Typically, the request for the startup module itself has only=scripts. That must apply
 824                 // only to the startup module content, and not to the module version computed here.
 825                 $context = new DerivativeResourceLoaderContext( $context );
 826                 $context->setModules( [] );
 827                 // Version hash must cover all resources, regardless of startup request itself.
 828                 $context->setOnly( null );
 829                 // Compute version hash based on content, not debug urls.
 830                 $context->setDebug( false );
 831
 832                 // Cache this somewhat expensive operation. Especially because some classes
 833                 // (e.g. startup module) iterate more than once over all modules to get versions.
 834                 $contextHash = $context->getHash();
 835                 if ( !array_key_exists( $contextHash, $this->versionHash ) ) {
 836                         if ( $this->enableModuleContentVersion() ) {
 837                                 // Detect changes directly
 838                                 $str = json_encode( $this->getModuleContent( $context ) );
 839                         } else {
 840                                 // Infer changes based on definition and other metrics
 841                                 $summary = $this->getDefinitionSummary( $context );
 842                                 if ( !isset( $summary['_cacheEpoch'] ) ) {
 843                                         throw new LogicException( 'getDefinitionSummary must call parent method' );
 844                                 }
 845                                 $str = json_encode( $summary );
 846
 847                                 $mtime = $this->getModifiedTime( $context );
 848                                 if ( $mtime !== null ) {
 849                                         // Support: MediaWiki 1.25 and earlier
 850                                         $str .= strval( $mtime );
 851                                 }
 852
 853                                 $mhash = $this->getModifiedHash( $context );
 854                                 if ( $mhash !== null ) {
 855                                         // Support: MediaWiki 1.25 and earlier
 856                                         $str .= strval( $mhash );
 857                                 }
 858                         }
 859
 860                         $this->versionHash[$contextHash] = ResourceLoader::makeHash( $str );
 861                 }
 862                 return $this->versionHash[$contextHash];
 863         }
 864
 865         /**
 866          * Whether to generate version hash based on module content.
 867          *
 868          * If a module requires database or file system access to build the module
 869          * content, consider disabling this in favour of manually tracking relevant
 870          * aspects in getDefinitionSummary(). See getVersionHash() for how this is used.
 871          *
 872          * @return bool
 873          */
 874         public function enableModuleContentVersion() {
 875                 return false;
 876         }
 877
 878         /**
 879          * Get the definition summary for this module.
 880          *
 881          * This is the method subclasses are recommended to use to track values in their
 882          * version hash. Call this in getVersionHash() and pass it to e.g. json_encode.
 883          *
 884          * Subclasses must call the parent getDefinitionSummary() and build on that.
 885          * It is recommended that each subclass appends its own new array. This prevents
 886          * clashes or accidental overwrites of existing keys and gives each subclass
 887          * its own scope for simple array keys.
 888          *
 889          * @code
 890          *     $summary = parent::getDefinitionSummary( $context );
 891          *     $summary[] = [
 892          *         'foo' => 123,
 893          *         'bar' => 'quux',
 894          *     ];
 895          *     return $summary;
 896          * @endcode
 897          *
 898          * Return an array containing values from all significant properties of this
 899          * module's definition.
 900          *
 901          * Be careful not to normalise too much. Especially preserve the order of things
 902          * that carry significance in getScript and getStyles (T39812).
 903          *
 904          * Avoid including things that are insiginificant (e.g. order of message keys is
 905          * insignificant and should be sorted to avoid unnecessary cache invalidation).
 906          *
 907          * This data structure must exclusively contain arrays and scalars as values (avoid
 908          * object instances) to allow simple serialisation using json_encode.
 909          *
 910          * If modules have a hash or timestamp from another source, that may be incuded as-is.
 911          *
 912          * A number of utility methods are available to help you gather data. These are not
 913          * called by default and must be included by the subclass' getDefinitionSummary().
 914          *
 915          * - getMessageBlob()
 916          *
 917          * @since 1.23
 918          * @param ResourceLoaderContext $context
 919          * @return array|null
 920          */
 921         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 922                 return [
 923                         '_class' => static::class,
 924                         '_cacheEpoch' => $this->getConfig()->get( 'CacheEpoch' ),
 925                 ];
 926         }
 927
 928         /**
 929          * Get this module's last modification timestamp for a given context.
 930          *
 931          * @deprecated since 1.26 Use getDefinitionSummary() instead
 932          * @param ResourceLoaderContext $context
 933          * @return int|null UNIX timestamp
 934          */
 935         public function getModifiedTime( ResourceLoaderContext $context ) {
 936                 return null;
 937         }
 938
 939         /**
 940          * Helper method for providing a version hash to getVersionHash().
 941          *
 942          * @deprecated since 1.26 Use getDefinitionSummary() instead
 943          * @param ResourceLoaderContext $context
 944          * @return string|null Hash
 945          */
 946         public function getModifiedHash( ResourceLoaderContext $context ) {
 947                 return null;
 948         }
 949
 950         /**
 951          * Back-compat dummy for old subclass implementations of getModifiedTime().
 952          *
 953          * This method used to use ObjectCache to track when a hash was first seen. That principle
 954          * stems from a time that ResourceLoader could only identify module versions by timestamp.
 955          * That is no longer the case. Use getDefinitionSummary() directly.
 956          *
 957          * @deprecated since 1.26 Superseded by getVersionHash()
 958          * @param ResourceLoaderContext $context
 959          * @return int UNIX timestamp
 960          */
 961         public function getHashMtime( ResourceLoaderContext $context ) {
 962                 if ( !is_string( $this->getModifiedHash( $context ) ) ) {
 963                         return 1;
 964                 }
 965                 // Dummy that is > 1
 966                 return 2;
 967         }
 968
 969         /**
 970          * Back-compat dummy for old subclass implementations of getModifiedTime().
 971          *
 972          * @since 1.23
 973          * @deprecated since 1.26 Superseded by getVersionHash()
 974          * @param ResourceLoaderContext $context
 975          * @return int UNIX timestamp
 976          */
 977         public function getDefinitionMtime( ResourceLoaderContext $context ) {
 978                 if ( $this->getDefinitionSummary( $context ) === null ) {
 979                         return 1;
 980                 }
 981                 // Dummy that is > 1
 982                 return 2;
 983         }
 984
 985         /**
 986          * Check whether this module is known to be empty. If a child class
 987          * has an easy and cheap way to determine that this module is
 988          * definitely going to be empty, it should override this method to
 989          * return true in that case. Callers may optimize the request for this
 990          * module away if this function returns true.
 991          * @param ResourceLoaderContext $context
 992          * @return bool
 993          */
 994         public function isKnownEmpty( ResourceLoaderContext $context ) {
 995                 return false;
 996         }
 997
 998         /**
 999          * Check whether this module should be embeded rather than linked
1000          *
1001          * Modules returning true here will be embedded rather than loaded by
1002          * ResourceLoaderClientHtml.
1003          *
1004          * @since 1.30
1005          * @param ResourceLoaderContext $context
1006          * @return bool
1007          */
1008         public function shouldEmbedModule( ResourceLoaderContext $context ) {
1009                 return $this->getGroup() === 'private';
1010         }
1011
1012         /** @var JSParser Lazy-initialized; use self::javaScriptParser() */
1013         private static $jsParser;
1014         private static $parseCacheVersion = 1;
1015
1016         /**
1017          * Validate a given script file; if valid returns the original source.
1018          * If invalid, returns replacement JS source that throws an exception.
1019          *
1020          * @param string $fileName
1021          * @param string $contents
1022          * @return string JS with the original, or a replacement error
1023          */
1024         protected function validateScriptFile( $fileName, $contents ) {
1025                 if ( !$this->getConfig()->get( 'ResourceLoaderValidateJS' ) ) {
1026                         return $contents;
1027                 }
1028                 $cache = ObjectCache::getMainWANInstance();
1029                 return $cache->getWithSetCallback(
1030                         $cache->makeGlobalKey(
1031                                 'resourceloader',
1032                                 'jsparse',
1033                                 self::$parseCacheVersion,
1034                                 md5( $contents ),
1035                                 $fileName
1036                         ),
1037                         $cache::TTL_WEEK,
1038                         function () use ( $contents, $fileName ) {
1039                                 $parser = self::javaScriptParser();
1040                                 try {
1041                                         $parser->parse( $contents, $fileName, 1 );
1042                                         $result = $contents;
1043                                 } catch ( Exception $e ) {
1044                                         // We'll save this to cache to avoid having to re-validate broken JS
1045                                         $err = $e->getMessage();
1046                                         $result = "mw.log.error(" .
1047                                                 Xml::encodeJsVar( "JavaScript parse error: $err" ) . ");";
1048                                 }
1049                                 return $result;
1050                         }
1051                 );
1052         }
1053
1054         /**
1055          * @return JSParser
1056          */
1057         protected static function javaScriptParser() {
1058                 if ( !self::$jsParser ) {
1059                         self::$jsParser = new JSParser();
1060                 }
1061                 return self::$jsParser;
1062         }
1063
1064         /**
1065          * Safe version of filemtime(), which doesn't throw a PHP warning if the file doesn't exist.
1066          * Defaults to 1.
1067          *
1068          * @param string $filePath File path
1069          * @return int UNIX timestamp
1070          */
1071         protected static function safeFilemtime( $filePath ) {
1072                 MediaWiki\suppressWarnings();
1073                 $mtime = filemtime( $filePath ) ?: 1;
1074                 MediaWiki\restoreWarnings();
1075                 return $mtime;
1076         }
1077
1078         /**
1079          * Compute a non-cryptographic string hash of a file's contents.
1080          * If the file does not exist or cannot be read, returns an empty string.
1081          *
1082          * @since 1.26 Uses MD4 instead of SHA1.
1083          * @param string $filePath File path
1084          * @return string Hash
1085          */
1086         protected static function safeFileHash( $filePath ) {
1087                 return FileContentsHasher::getFileContentsHash( $filePath );
1088         }
1089 }