includes/resourceloader/ResourceLoaderModule.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  * @author Trevor Parscal
  20  * @author Roan Kattouw
  21  */
  22
  23 use MediaWiki\MediaWikiServices;
  24 use Psr\Log\LoggerAwareInterface;
  25 use Psr\Log\LoggerInterface;
  26 use Psr\Log\NullLogger;
  27 use Wikimedia\AtEase\AtEase;
  28 use Wikimedia\RelPath;
  29 use Wikimedia\ScopedCallback;
  30
  31 /**
  32  * Abstraction for ResourceLoader modules, with name registration and maxage functionality.
  33  *
  34  * @ingroup ResourceLoader
  35  * @since 1.17
  36  */
  37 abstract class ResourceLoaderModule implements LoggerAwareInterface {
  38         /** @var Config */
  39         protected $config;
  40         /** @var LoggerInterface */
  41         protected $logger;
  42
  43         /**
  44          * Script and style modules form a hierarchy of trustworthiness, with core modules
  45          * like skins and jQuery as most trustworthy, and user scripts as least trustworthy. We can
  46          * limit the types of scripts and styles we allow to load on, say, sensitive special
  47          * pages like Special:UserLogin and Special:Preferences
  48          * @var int
  49          */
  50         protected $origin = self::ORIGIN_CORE_SITEWIDE;
  51
  52         /** @var string|null Module name */
  53         protected $name = null;
  54         /** @var string[] What client platforms the module targets (e.g. desktop, mobile) */
  55         protected $targets = [ 'desktop' ];
  56
  57         /** @var array Map of (variant => indirect file dependencies) */
  58         protected $fileDeps = [];
  59         /** @var array Map of (language => in-object cache for message blob) */
  60         protected $msgBlobs = [];
  61         /** @var array Map of (context hash => cached module version hash) */
  62         protected $versionHash = [];
  63         /** @var array Map of (context hash => cached module content) */
  64         protected $contents = [];
  65
  66         /** @var string|bool Deprecation string or true if deprecated; false otherwise */
  67         protected $deprecated = false;
  68
  69         /** @var string Scripts only */
  70         const TYPE_SCRIPTS = 'scripts';
  71         /** @var string Styles only */
  72         const TYPE_STYLES = 'styles';
  73         /** @var string Scripts and styles */
  74         const TYPE_COMBINED = 'combined';
  75
  76         /** @var string Module only has styles (loaded via <style> or <link rel=stylesheet>) */
  77         const LOAD_STYLES = 'styles';
  78         /** @var string Module may have other resources (loaded via mw.loader from a script) */
  79         const LOAD_GENERAL = 'general';
  80
  81         /** @var int Sitewide core module like a skin file or jQuery component */
  82         const ORIGIN_CORE_SITEWIDE = 1;
  83         /** @var int Per-user module generated by the software */
  84         const ORIGIN_CORE_INDIVIDUAL = 2;
  85         /**
  86          * Sitewide module generated from user-editable files, like MediaWiki:Common.js,
  87          * or modules accessible to multiple users, such as those generated by the Gadgets extension.
  88          * @var int
  89          */
  90         const ORIGIN_USER_SITEWIDE = 3;
  91         /** @var int Per-user module generated from user-editable files, like User:Me/vector.js */
  92         const ORIGIN_USER_INDIVIDUAL = 4;
  93         /** @var int An access constant; make sure this is kept as the largest number in this group */
  94         const ORIGIN_ALL = 10;
  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( ResourceLoaderContext $context ) {
 132                 return MediaWikiServices::getInstance()->getContentLanguage()->getDir() !==
 133                         $context->getDirection();
 134         }
 135
 136         /**
 137          * Get JS representing deprecation information for the current module if available
 138          *
 139          * @return string JavaScript code
 140          */
 141         public function getDeprecationInformation() {
 142                 $deprecationInfo = $this->deprecated;
 143                 if ( $deprecationInfo ) {
 144                         $name = $this->getName();
 145                         $warning = 'This page is using the deprecated ResourceLoader module "' . $name . '".';
 146                         if ( is_string( $deprecationInfo ) ) {
 147                                 $warning .= "\n" . $deprecationInfo;
 148                         }
 149                         return 'mw.log.warn(' . ResourceLoader::encodeJsonForScript( $warning ) . ');';
 150                 } else {
 151                         return '';
 152                 }
 153         }
 154
 155         /**
 156          * Get all JS for this module for a given language and skin.
 157          * Includes all relevant JS except loader scripts.
 158          *
 159          * For "plain" script modules, this should return a string with JS code. For multi-file modules
 160          * where require() is used to load one file from another file, this should return an array
 161          * structured as follows:
 162          * [
 163          *     'files' => [
 164          *         'file1.js' => [ 'type' => 'script', 'content' => 'JS code' ],
 165          *         'file2.js' => [ 'type' => 'script', 'content' => 'JS code' ],
 166          *         'data.json' => [ 'type' => 'data', 'content' => array ]
 167          *     ],
 168          *     'main' => 'file1.js'
 169          * ]
 170          *
 171          * @param ResourceLoaderContext $context
 172          * @return string|array JavaScript code (string), or multi-file structure described above (array)
 173          */
 174         public function getScript( ResourceLoaderContext $context ) {
 175                 // Stub, override expected
 176                 return '';
 177         }
 178
 179         /**
 180          * Takes named templates by the module and returns an array mapping.
 181          *
 182          * @return string[] Array of templates mapping template alias to content
 183          */
 184         public function getTemplates() {
 185                 // Stub, override expected.
 186                 return [];
 187         }
 188
 189         /**
 190          * @return Config
 191          * @since 1.24
 192          */
 193         public function getConfig() {
 194                 if ( $this->config === null ) {
 195                         // Ugh, fall back to default
 196                         $this->config = MediaWikiServices::getInstance()->getMainConfig();
 197                 }
 198
 199                 return $this->config;
 200         }
 201
 202         /**
 203          * @param Config $config
 204          * @since 1.24
 205          */
 206         public function setConfig( Config $config ) {
 207                 $this->config = $config;
 208         }
 209
 210         /**
 211          * @since 1.27
 212          * @param LoggerInterface $logger
 213          */
 214         public function setLogger( LoggerInterface $logger ) {
 215                 $this->logger = $logger;
 216         }
 217
 218         /**
 219          * @since 1.27
 220          * @return LoggerInterface
 221          */
 222         protected function getLogger() {
 223                 if ( !$this->logger ) {
 224                         $this->logger = new NullLogger();
 225                 }
 226                 return $this->logger;
 227         }
 228
 229         /**
 230          * Get the URL or URLs to load for this module's JS in debug mode.
 231          * The default behavior is to return a load.php?only=scripts URL for
 232          * the module, but file-based modules will want to override this to
 233          * load the files directly.
 234          *
 235          * This function is called only when 1) we're in debug mode, 2) there
 236          * is no only= parameter and 3) supportsURLLoading() returns true.
 237          * #2 is important to prevent an infinite loop, therefore this function
 238          * MUST return either an only= URL or a non-load.php URL.
 239          *
 240          * @param ResourceLoaderContext $context
 241          * @return array Array of URLs
 242          */
 243         public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
 244                 $resourceLoader = $context->getResourceLoader();
 245                 $derivative = new DerivativeResourceLoaderContext( $context );
 246                 $derivative->setModules( [ $this->getName() ] );
 247                 $derivative->setOnly( 'scripts' );
 248                 $derivative->setDebug( true );
 249
 250                 $url = $resourceLoader->createLoaderURL(
 251                         $this->getSource(),
 252                         $derivative
 253                 );
 254
 255                 return [ $url ];
 256         }
 257
 258         /**
 259          * Whether this module supports URL loading. If this function returns false,
 260          * getScript() will be used even in cases (debug mode, no only param) where
 261          * getScriptURLsForDebug() would normally be used instead.
 262          * @return bool
 263          */
 264         public function supportsURLLoading() {
 265                 return true;
 266         }
 267
 268         /**
 269          * Get all CSS for this module for a given skin.
 270          *
 271          * @param ResourceLoaderContext $context
 272          * @return array List of CSS strings or array of CSS strings keyed by media type.
 273          *  like [ 'screen' => '.foo { width: 0 }' ];
 274          *  or [ 'screen' => [ '.foo { width: 0 }' ] ];
 275          */
 276         public function getStyles( ResourceLoaderContext $context ) {
 277                 // Stub, override expected
 278                 return [];
 279         }
 280
 281         /**
 282          * Get the URL or URLs to load for this module's CSS in debug mode.
 283          * The default behavior is to return a load.php?only=styles URL for
 284          * the module, but file-based modules will want to override this to
 285          * load the files directly. See also getScriptURLsForDebug()
 286          *
 287          * @param ResourceLoaderContext $context
 288          * @return array [ mediaType => [ URL1, URL2, ... ], ... ]
 289          */
 290         public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
 291                 $resourceLoader = $context->getResourceLoader();
 292                 $derivative = new DerivativeResourceLoaderContext( $context );
 293                 $derivative->setModules( [ $this->getName() ] );
 294                 $derivative->setOnly( 'styles' );
 295                 $derivative->setDebug( true );
 296
 297                 $url = $resourceLoader->createLoaderURL(
 298                         $this->getSource(),
 299                         $derivative
 300                 );
 301
 302                 return [ 'all' => [ $url ] ];
 303         }
 304
 305         /**
 306          * Get the messages needed for this module.
 307          *
 308          * To get a JSON blob with messages, use MessageBlobStore::get()
 309          *
 310          * @return array List of message keys. Keys may occur more than once
 311          */
 312         public function getMessages() {
 313                 // Stub, override expected
 314                 return [];
 315         }
 316
 317         /**
 318          * Get the group this module is in.
 319          *
 320          * @return string Group name
 321          */
 322         public function getGroup() {
 323                 // Stub, override expected
 324                 return null;
 325         }
 326
 327         /**
 328          * Get the source of this module. Should only be overridden for foreign modules.
 329          *
 330          * @return string Source name, 'local' for local modules
 331          */
 332         public function getSource() {
 333                 // Stub, override expected
 334                 return 'local';
 335         }
 336
 337         /**
 338          * Get a list of modules this module depends on.
 339          *
 340          * Dependency information is taken into account when loading a module
 341          * on the client side.
 342          *
 343          * Note: It is expected that $context will be made non-optional in the near
 344          * future.
 345          *
 346          * @param ResourceLoaderContext|null $context
 347          * @return array List of module names as strings
 348          */
 349         public function getDependencies( ResourceLoaderContext $context = null ) {
 350                 // Stub, override expected
 351                 return [];
 352         }
 353
 354         /**
 355          * Get target(s) for the module, eg ['desktop'] or ['desktop', 'mobile']
 356          *
 357          * @return array Array of strings
 358          */
 359         public function getTargets() {
 360                 return $this->targets;
 361         }
 362
 363         /**
 364          * Get the module's load type.
 365          *
 366          * @since 1.28
 367          * @return string ResourceLoaderModule LOAD_* constant
 368          */
 369         public function getType() {
 370                 return self::LOAD_GENERAL;
 371         }
 372
 373         /**
 374          * Get the skip function.
 375          *
 376          * Modules that provide fallback functionality can provide a "skip function". This
 377          * function, if provided, will be passed along to the module registry on the client.
 378          * When this module is loaded (either directly or as a dependency of another module),
 379          * then this function is executed first. If the function returns true, the module will
 380          * instantly be considered "ready" without requesting the associated module resources.
 381          *
 382          * The value returned here must be valid javascript for execution in a private function.
 383          * It must not contain the "function () {" and "}" wrapper though.
 384          *
 385          * @return string|null A JavaScript function body returning a boolean value, or null
 386          */
 387         public function getSkipFunction() {
 388                 return null;
 389         }
 390
 391         /**
 392          * Get the files this module depends on indirectly for a given skin.
 393          *
 394          * These are only image files referenced by the module's stylesheet.
 395          *
 396          * @param ResourceLoaderContext $context
 397          * @return array List of files
 398          */
 399         protected function getFileDependencies( ResourceLoaderContext $context ) {
 400                 $vary = self::getVary( $context );
 401
 402                 // Try in-object cache first
 403                 if ( !isset( $this->fileDeps[$vary] ) ) {
 404                         $dbr = wfGetDB( DB_REPLICA );
 405                         $deps = $dbr->selectField( 'module_deps',
 406                                 'md_deps',
 407                                 [
 408                                         'md_module' => $this->getName(),
 409                                         'md_skin' => $vary,
 410                                 ],
 411                                 __METHOD__
 412                         );
 413
 414                         if ( !is_null( $deps ) ) {
 415                                 $this->fileDeps[$vary] = self::expandRelativePaths(
 416                                         (array)json_decode( $deps, true )
 417                                 );
 418                         } else {
 419                                 $this->fileDeps[$vary] = [];
 420                         }
 421                 }
 422                 return $this->fileDeps[$vary];
 423         }
 424
 425         /**
 426          * Set in-object cache for file dependencies.
 427          *
 428          * This is used to retrieve data in batches. See ResourceLoader::preloadModuleInfo().
 429          * To save the data, use saveFileDependencies().
 430          *
 431          * @param ResourceLoaderContext $context
 432          * @param string[] $files Array of file names
 433          */
 434         public function setFileDependencies( ResourceLoaderContext $context, $files ) {
 435                 $vary = self::getVary( $context );
 436                 $this->fileDeps[$vary] = $files;
 437         }
 438
 439         /**
 440          * Set the files this module depends on indirectly for a given skin.
 441          *
 442          * @since 1.27
 443          * @param ResourceLoaderContext $context
 444          * @param array $localFileRefs List of files
 445          */
 446         protected function saveFileDependencies( ResourceLoaderContext $context, $localFileRefs ) {
 447                 try {
 448                         // Related bugs and performance considerations:
 449                         // 1. Don't needlessly change the database value with the same list in a
 450                         //    different order or with duplicates.
 451                         // 2. Use relative paths to avoid ghost entries when $IP changes. (T111481)
 452                         // 3. Don't needlessly replace the database with the same value
 453                         //    just because $IP changed (e.g. when upgrading a wiki).
 454                         // 4. Don't create an endless replace loop on every request for this
 455                         //    module when '../' is used anywhere. Even though both are expanded
 456                         //    (one expanded by getFileDependencies from the DB, the other is
 457                         //    still raw as originally read by RL), the latter has not
 458                         //    been normalized yet.
 459
 460                         // Normalise
 461                         $localFileRefs = array_values( array_unique( $localFileRefs ) );
 462                         sort( $localFileRefs );
 463                         $localPaths = self::getRelativePaths( $localFileRefs );
 464                         $storedPaths = self::getRelativePaths( $this->getFileDependencies( $context ) );
 465
 466                         if ( $localPaths === $storedPaths ) {
 467                                 // Unchanged. Avoid needless database query (especially master conn!).
 468                                 return;
 469                         }
 470
 471                         // The file deps list has changed, we want to update it.
 472                         $vary = self::getVary( $context );
 473                         $cache = ObjectCache::getLocalClusterInstance();
 474                         $key = $cache->makeKey( __METHOD__, $this->getName(), $vary );
 475                         $scopeLock = $cache->getScopedLock( $key, 0 );
 476                         if ( !$scopeLock ) {
 477                                 // Another request appears to be doing this update already.
 478                                 // Avoid write slams (T124649).
 479                                 return;
 480                         }
 481
 482                         // No needless escaping as this isn't HTML output.
 483                         // Only stored in the database and parsed in PHP.
 484                         $deps = json_encode( $localPaths, JSON_UNESCAPED_SLASHES );
 485                         $dbw = wfGetDB( DB_MASTER );
 486                         $dbw->upsert( 'module_deps',
 487                                 [
 488                                         'md_module' => $this->getName(),
 489                                         'md_skin' => $vary,
 490                                         'md_deps' => $deps,
 491                                 ],
 492                                 [ [ 'md_module', 'md_skin' ] ],
 493                                 [
 494                                         'md_deps' => $deps,
 495                                 ],
 496                                 __METHOD__
 497                         );
 498
 499                         if ( $dbw->trxLevel() ) {
 500                                 $dbw->onTransactionResolution(
 501                                         function () use ( &$scopeLock ) {
 502                                                 ScopedCallback::consume( $scopeLock ); // release after commit
 503                                         },
 504                                         __METHOD__
 505                                 );
 506                         }
 507                 } catch ( Exception $e ) {
 508                         // Probably a DB failure. Either the read query from getFileDependencies(),
 509                         // or the write query above.
 510                         wfDebugLog( 'resourceloader', __METHOD__ . ": failed to update DB: $e" );
 511                 }
 512         }
 513
 514         /**
 515          * Make file paths relative to MediaWiki directory.
 516          *
 517          * This is used to make file paths safe for storing in a database without the paths
 518          * becoming stale or incorrect when MediaWiki is moved or upgraded (T111481).
 519          *
 520          * @since 1.27
 521          * @param array $filePaths
 522          * @return array
 523          */
 524         public static function getRelativePaths( array $filePaths ) {
 525                 global $IP;
 526                 return array_map( function ( $path ) use ( $IP ) {
 527                         return RelPath::getRelativePath( $path, $IP );
 528                 }, $filePaths );
 529         }
 530
 531         /**
 532          * Expand directories relative to $IP.
 533          *
 534          * @since 1.27
 535          * @param array $filePaths
 536          * @return array
 537          */
 538         public static function expandRelativePaths( array $filePaths ) {
 539                 global $IP;
 540                 return array_map( function ( $path ) use ( $IP ) {
 541                         return RelPath::joinPath( $IP, $path );
 542                 }, $filePaths );
 543         }
 544
 545         /**
 546          * Get the hash of the message blob.
 547          *
 548          * @since 1.27
 549          * @param ResourceLoaderContext $context
 550          * @return string|null JSON blob or null if module has no messages
 551          */
 552         protected function getMessageBlob( ResourceLoaderContext $context ) {
 553                 if ( !$this->getMessages() ) {
 554                         // Don't bother consulting MessageBlobStore
 555                         return null;
 556                 }
 557                 // Message blobs may only vary language, not by context keys
 558                 $lang = $context->getLanguage();
 559                 if ( !isset( $this->msgBlobs[$lang] ) ) {
 560                         $this->getLogger()->warning( 'Message blob for {module} should have been preloaded', [
 561                                 'module' => $this->getName(),
 562                         ] );
 563                         $store = $context->getResourceLoader()->getMessageBlobStore();
 564                         $this->msgBlobs[$lang] = $store->getBlob( $this, $lang );
 565                 }
 566                 return $this->msgBlobs[$lang];
 567         }
 568
 569         /**
 570          * Set in-object cache for message blobs.
 571          *
 572          * Used to allow fetching of message blobs in batches. See ResourceLoader::preloadModuleInfo().
 573          *
 574          * @since 1.27
 575          * @param string|null $blob JSON blob or null
 576          * @param string $lang Language code
 577          */
 578         public function setMessageBlob( $blob, $lang ) {
 579                 $this->msgBlobs[$lang] = $blob;
 580         }
 581
 582         /**
 583          * Get headers to send as part of a module web response.
 584          *
 585          * It is not supported to send headers through this method that are
 586          * required to be unique or otherwise sent once in an HTTP response
 587          * because clients may make batch requests for multiple modules (as
 588          * is the default behaviour for ResourceLoader clients).
 589          *
 590          * For exclusive or aggregated headers, see ResourceLoader::sendResponseHeaders().
 591          *
 592          * @since 1.30
 593          * @param ResourceLoaderContext $context
 594          * @return string[] Array of HTTP response headers
 595          */
 596         final public function getHeaders( ResourceLoaderContext $context ) {
 597                 $headers = [];
 598
 599                 $formattedLinks = [];
 600                 foreach ( $this->getPreloadLinks( $context ) as $url => $attribs ) {
 601                         $link = "<{$url}>;rel=preload";
 602                         foreach ( $attribs as $key => $val ) {
 603                                 $link .= ";{$key}={$val}";
 604                         }
 605                         $formattedLinks[] = $link;
 606                 }
 607                 if ( $formattedLinks ) {
 608                         $headers[] = 'Link: ' . implode( ',', $formattedLinks );
 609                 }
 610
 611                 return $headers;
 612         }
 613
 614         /**
 615          * Get a list of resources that web browsers may preload.
 616          *
 617          * Behaviour of rel=preload link is specified at <https://www.w3.org/TR/preload/>.
 618          *
 619          * Use case for ResourceLoader originally part of T164299.
 620          *
 621          * @par Example
 622          * @code
 623          *     protected function getPreloadLinks() {
 624          *         return [
 625          *             'https://example.org/script.js' => [ 'as' => 'script' ],
 626          *             'https://example.org/image.png' => [ 'as' => 'image' ],
 627          *         ];
 628          *     }
 629          * @endcode
 630          *
 631          * @par Example using HiDPI image variants
 632          * @code
 633          *     protected function getPreloadLinks() {
 634          *         return [
 635          *             'https://example.org/logo.png' => [
 636          *                 'as' => 'image',
 637          *                 'media' => 'not all and (min-resolution: 2dppx)',
 638          *             ],
 639          *             'https://example.org/logo@2x.png' => [
 640          *                 'as' => 'image',
 641          *                 'media' => '(min-resolution: 2dppx)',
 642          *             ],
 643          *         ];
 644          *     }
 645          * @endcode
 646          *
 647          * @see ResourceLoaderModule::getHeaders
 648          * @since 1.30
 649          * @param ResourceLoaderContext $context
 650          * @return array Keyed by url, values must be an array containing
 651          *  at least an 'as' key. Optionally a 'media' key as well.
 652          */
 653         protected function getPreloadLinks( ResourceLoaderContext $context ) {
 654                 return [];
 655         }
 656
 657         /**
 658          * Get module-specific LESS variables, if any.
 659          *
 660          * @since 1.27
 661          * @param ResourceLoaderContext $context
 662          * @return array Module-specific LESS variables.
 663          */
 664         protected function getLessVars( ResourceLoaderContext $context ) {
 665                 return [];
 666         }
 667
 668         /**
 669          * Get an array of this module's resources. Ready for serving to the web.
 670          *
 671          * @since 1.26
 672          * @param ResourceLoaderContext $context
 673          * @return array
 674          */
 675         public function getModuleContent( ResourceLoaderContext $context ) {
 676                 $contextHash = $context->getHash();
 677                 // Cache this expensive operation. This calls builds the scripts, styles, and messages
 678                 // content which typically involves filesystem and/or database access.
 679                 if ( !array_key_exists( $contextHash, $this->contents ) ) {
 680                         $this->contents[$contextHash] = $this->buildContent( $context );
 681                 }
 682                 return $this->contents[$contextHash];
 683         }
 684
 685         /**
 686          * Bundle all resources attached to this module into an array.
 687          *
 688          * @since 1.26
 689          * @param ResourceLoaderContext $context
 690          * @return array
 691          */
 692         final protected function buildContent( ResourceLoaderContext $context ) {
 693                 $rl = $context->getResourceLoader();
 694                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 695                 $statStart = microtime( true );
 696
 697                 // This MUST build both scripts and styles, regardless of whether $context->getOnly()
 698                 // is 'scripts' or 'styles' because the result is used by getVersionHash which
 699                 // must be consistent regardless of the 'only' filter on the current request.
 700                 // Also, when introducing new module content resources (e.g. templates, headers),
 701                 // these should only be included in the array when they are non-empty so that
 702                 // existing modules not using them do not get their cache invalidated.
 703                 $content = [];
 704
 705                 // Scripts
 706                 // If we are in debug mode, we'll want to return an array of URLs if possible
 707                 // However, we can't do this if the module doesn't support it.
 708                 // We also can't do this if there is an only= parameter, because we have to give
 709                 // the module a way to return a load.php URL without causing an infinite loop
 710                 if ( $context->getDebug() && !$context->getOnly() && $this->supportsURLLoading() ) {
 711                         $scripts = $this->getScriptURLsForDebug( $context );
 712                 } else {
 713                         $scripts = $this->getScript( $context );
 714                         // Make the script safe to concatenate by making sure there is at least one
 715                         // trailing new line at the end of the content. Previously, this looked for
 716                         // a semi-colon instead, but that breaks concatenation if the semicolon
 717                         // is inside a comment like "// foo();". Instead, simply use a
 718                         // line break as separator which matches JavaScript native logic for implicitly
 719                         // ending statements even if a semi-colon is missing.
 720                         // Bugs: T29054, T162719.
 721                         if ( is_string( $scripts )
 722                                 && strlen( $scripts )
 723                                 && substr( $scripts, -1 ) !== "\n"
 724                         ) {
 725                                 $scripts .= "\n";
 726                         }
 727                 }
 728                 $content['scripts'] = $scripts;
 729
 730                 $styles = [];
 731                 // Don't create empty stylesheets like [ '' => '' ] for modules
 732                 // that don't *have* any stylesheets (T40024).
 733                 $stylePairs = $this->getStyles( $context );
 734                 if ( count( $stylePairs ) ) {
 735                         // If we are in debug mode without &only= set, we'll want to return an array of URLs
 736                         // See comment near shouldIncludeScripts() for more details
 737                         if ( $context->getDebug() && !$context->getOnly() && $this->supportsURLLoading() ) {
 738                                 $styles = [
 739                                         'url' => $this->getStyleURLsForDebug( $context )
 740                                 ];
 741                         } else {
 742                                 // Minify CSS before embedding in mw.loader.implement call
 743                                 // (unless in debug mode)
 744                                 if ( !$context->getDebug() ) {
 745                                         foreach ( $stylePairs as $media => $style ) {
 746                                                 // Can be either a string or an array of strings.
 747                                                 if ( is_array( $style ) ) {
 748                                                         $stylePairs[$media] = [];
 749                                                         foreach ( $style as $cssText ) {
 750                                                                 if ( is_string( $cssText ) ) {
 751                                                                         $stylePairs[$media][] =
 752                                                                                 ResourceLoader::filter( 'minify-css', $cssText );
 753                                                                 }
 754                                                         }
 755                                                 } elseif ( is_string( $style ) ) {
 756                                                         $stylePairs[$media] = ResourceLoader::filter( 'minify-css', $style );
 757                                                 }
 758                                         }
 759                                 }
 760                                 // Wrap styles into @media groups as needed and flatten into a numerical array
 761                                 $styles = [
 762                                         'css' => $rl->makeCombinedStyles( $stylePairs )
 763                                 ];
 764                         }
 765                 }
 766                 $content['styles'] = $styles;
 767
 768                 // Messages
 769                 $blob = $this->getMessageBlob( $context );
 770                 if ( $blob ) {
 771                         $content['messagesBlob'] = $blob;
 772                 }
 773
 774                 $templates = $this->getTemplates();
 775                 if ( $templates ) {
 776                         $content['templates'] = $templates;
 777                 }
 778
 779                 $headers = $this->getHeaders( $context );
 780                 if ( $headers ) {
 781                         $content['headers'] = $headers;
 782                 }
 783
 784                 $statTiming = microtime( true ) - $statStart;
 785                 $statName = strtr( $this->getName(), '.', '_' );
 786                 $stats->timing( "resourceloader_build.all", 1000 * $statTiming );
 787                 $stats->timing( "resourceloader_build.$statName", 1000 * $statTiming );
 788
 789                 return $content;
 790         }
 791
 792         /**
 793          * Get a string identifying the current version of this module in a given context.
 794          *
 795          * Whenever anything happens that changes the module's response (e.g. scripts, styles, and
 796          * messages) this value must change. This value is used to store module responses in cache.
 797          * (Both client-side and server-side.)
 798          *
 799          * It is not recommended to override this directly. Use getDefinitionSummary() instead.
 800          * If overridden, one must call the parent getVersionHash(), append data and re-hash.
 801          *
 802          * This method should be quick because it is frequently run by ResourceLoaderStartUpModule to
 803          * propagate changes to the client and effectively invalidate cache.
 804          *
 805          * @since 1.26
 806          * @param ResourceLoaderContext $context
 807          * @return string Hash (should use ResourceLoader::makeHash)
 808          */
 809         public function getVersionHash( ResourceLoaderContext $context ) {
 810                 // Cache this somewhat expensive operation. Especially because some classes
 811                 // (e.g. startup module) iterate more than once over all modules to get versions.
 812                 $contextHash = $context->getHash();
 813                 if ( !array_key_exists( $contextHash, $this->versionHash ) ) {
 814                         if ( $this->enableModuleContentVersion() ) {
 815                                 // Detect changes directly by hashing the module contents.
 816                                 $str = json_encode( $this->getModuleContent( $context ) );
 817                         } else {
 818                                 // Infer changes based on definition and other metrics
 819                                 $summary = $this->getDefinitionSummary( $context );
 820                                 if ( !isset( $summary['_class'] ) ) {
 821                                         throw new LogicException( 'getDefinitionSummary must call parent method' );
 822                                 }
 823                                 $str = json_encode( $summary );
 824                         }
 825
 826                         $this->versionHash[$contextHash] = ResourceLoader::makeHash( $str );
 827                 }
 828                 return $this->versionHash[$contextHash];
 829         }
 830
 831         /**
 832          * Whether to generate version hash based on module content.
 833          *
 834          * If a module requires database or file system access to build the module
 835          * content, consider disabling this in favour of manually tracking relevant
 836          * aspects in getDefinitionSummary(). See getVersionHash() for how this is used.
 837          *
 838          * @return bool
 839          */
 840         public function enableModuleContentVersion() {
 841                 return false;
 842         }
 843
 844         /**
 845          * Get the definition summary for this module.
 846          *
 847          * This is the method subclasses are recommended to use to track values in their
 848          * version hash. Call this in getVersionHash() and pass it to e.g. json_encode.
 849          *
 850          * Subclasses must call the parent getDefinitionSummary() and build on that.
 851          * It is recommended that each subclass appends its own new array. This prevents
 852          * clashes or accidental overwrites of existing keys and gives each subclass
 853          * its own scope for simple array keys.
 854          *
 855          * @code
 856          *     $summary = parent::getDefinitionSummary( $context );
 857          *     $summary[] = [
 858          *         'foo' => 123,
 859          *         'bar' => 'quux',
 860          *     ];
 861          *     return $summary;
 862          * @endcode
 863          *
 864          * Return an array containing values from all significant properties of this
 865          * module's definition.
 866          *
 867          * Be careful not to normalise too much. Especially preserve the order of things
 868          * that carry significance in getScript and getStyles (T39812).
 869          *
 870          * Avoid including things that are insiginificant (e.g. order of message keys is
 871          * insignificant and should be sorted to avoid unnecessary cache invalidation).
 872          *
 873          * This data structure must exclusively contain arrays and scalars as values (avoid
 874          * object instances) to allow simple serialisation using json_encode.
 875          *
 876          * If modules have a hash or timestamp from another source, that may be incuded as-is.
 877          *
 878          * A number of utility methods are available to help you gather data. These are not
 879          * called by default and must be included by the subclass' getDefinitionSummary().
 880          *
 881          * - getMessageBlob()
 882          *
 883          * @since 1.23
 884          * @param ResourceLoaderContext $context
 885          * @return array|null
 886          */
 887         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 888                 return [
 889                         '_class' => static::class,
 890                         // Make sure that when filter cache for minification is invalidated,
 891                         // we also change the HTTP urls and mw.loader.store keys (T176884).
 892                         '_cacheVersion' => ResourceLoader::CACHE_VERSION,
 893                 ];
 894         }
 895
 896         /**
 897          * Check whether this module is known to be empty. If a child class
 898          * has an easy and cheap way to determine that this module is
 899          * definitely going to be empty, it should override this method to
 900          * return true in that case. Callers may optimize the request for this
 901          * module away if this function returns true.
 902          * @param ResourceLoaderContext $context
 903          * @return bool
 904          */
 905         public function isKnownEmpty( ResourceLoaderContext $context ) {
 906                 return false;
 907         }
 908
 909         /**
 910          * Check whether this module should be embeded rather than linked
 911          *
 912          * Modules returning true here will be embedded rather than loaded by
 913          * ResourceLoaderClientHtml.
 914          *
 915          * @since 1.30
 916          * @param ResourceLoaderContext $context
 917          * @return bool
 918          */
 919         public function shouldEmbedModule( ResourceLoaderContext $context ) {
 920                 return $this->getGroup() === 'private';
 921         }
 922
 923         /** @var JSParser Lazy-initialized; use self::javaScriptParser() */
 924         private static $jsParser;
 925         private static $parseCacheVersion = 1;
 926
 927         /**
 928          * Validate a given script file; if valid returns the original source.
 929          * If invalid, returns replacement JS source that throws an exception.
 930          *
 931          * @param string $fileName
 932          * @param string $contents
 933          * @return string JS with the original, or a replacement error
 934          */
 935         protected function validateScriptFile( $fileName, $contents ) {
 936                 if ( !$this->getConfig()->get( 'ResourceLoaderValidateJS' ) ) {
 937                         return $contents;
 938                 }
 939                 $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
 940                 return $cache->getWithSetCallback(
 941                         $cache->makeGlobalKey(
 942                                 'resourceloader-jsparse',
 943                                 self::$parseCacheVersion,
 944                                 md5( $contents ),
 945                                 $fileName
 946                         ),
 947                         $cache::TTL_WEEK,
 948                         function () use ( $contents, $fileName ) {
 949                                 $parser = self::javaScriptParser();
 950                                 $err = null;
 951                                 try {
 952                                         AtEase::suppressWarnings();
 953                                         $parser->parse( $contents, $fileName, 1 );
 954                                 } catch ( Exception $e ) {
 955                                         $err = $e;
 956                                 } finally {
 957                                         AtEase::restoreWarnings();
 958                                 }
 959                                 if ( $err ) {
 960                                         // Send the error to the browser console client-side.
 961                                         // By returning this as replacement for the actual script,
 962                                         // we ensure modules are safe to load in a batch request,
 963                                         // without causing other unrelated modules to break.
 964                                         return 'mw.log.error(' .
 965                                                 Xml::encodeJsVar( 'JavaScript parse error: ' . $err->getMessage() ) .
 966                                                 ');';
 967                                 }
 968                                 return $contents;
 969                         }
 970                 );
 971         }
 972
 973         /**
 974          * @return JSParser
 975          */
 976         protected static function javaScriptParser() {
 977                 if ( !self::$jsParser ) {
 978                         self::$jsParser = new JSParser();
 979                 }
 980                 return self::$jsParser;
 981         }
 982
 983         /**
 984          * Safe version of filemtime(), which doesn't throw a PHP warning if the file doesn't exist.
 985          * Defaults to 1.
 986          *
 987          * @param string $filePath File path
 988          * @return int UNIX timestamp
 989          */
 990         protected static function safeFilemtime( $filePath ) {
 991                 AtEase::suppressWarnings();
 992                 $mtime = filemtime( $filePath ) ?: 1;
 993                 AtEase::restoreWarnings();
 994                 return $mtime;
 995         }
 996
 997         /**
 998          * Compute a non-cryptographic string hash of a file's contents.
 999          * If the file does not exist or cannot be read, returns an empty string.
1000          *
1001          * @since 1.26 Uses MD4 instead of SHA1.
1002          * @param string $filePath File path
1003          * @return string Hash
1004          */
1005         protected static function safeFileHash( $filePath ) {
1006                 return FileContentsHasher::getFileContentsHash( $filePath );
1007         }
1008
1009         /**
1010          * Get vary string.
1011          *
1012          * @internal For internal use only.
1013          * @param ResourceLoaderContext $context
1014          * @return string Vary string
1015          */
1016         public static function getVary( ResourceLoaderContext $context ) {
1017                 return implode( '|', [
1018                         $context->getSkin(),
1019                         $context->getLanguage(),
1020                 ] );
1021         }
1022 }