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          * @param ResourceLoaderContext|null $context Missing $context is deprecated in 1.34
 140          * @return string JavaScript code
 141          */
 142         public function getDeprecationInformation( ResourceLoaderContext $context = null ) {
 143                 if ( $context === null ) {
 144                         wfDeprecated( __METHOD__ . ' without a ResourceLoader context', '1.34' );
 145                 }
 146                 $deprecationInfo = $this->deprecated;
 147                 if ( $deprecationInfo ) {
 148                         $name = $this->getName();
 149                         $warning = 'This page is using the deprecated ResourceLoader module "' . $name . '".';
 150                         if ( is_string( $deprecationInfo ) ) {
 151                                 $warning .= "\n" . $deprecationInfo;
 152                         }
 153                         if ( $context === null ) {
 154                                 return 'mw.log.warn(' . ResourceLoader::encodeJsonForScript( $warning ) . ');';
 155                         }
 156                         return 'mw.log.warn(' . $context->encodeJson( $warning ) . ');';
 157                 } else {
 158                         return '';
 159                 }
 160         }
 161
 162         /**
 163          * Get all JS for this module for a given language and skin.
 164          * Includes all relevant JS except loader scripts.
 165          *
 166          * For "plain" script modules, this should return a string with JS code. For multi-file modules
 167          * where require() is used to load one file from another file, this should return an array
 168          * structured as follows:
 169          * [
 170          *     'files' => [
 171          *         'file1.js' => [ 'type' => 'script', 'content' => 'JS code' ],
 172          *         'file2.js' => [ 'type' => 'script', 'content' => 'JS code' ],
 173          *         'data.json' => [ 'type' => 'data', 'content' => array ]
 174          *     ],
 175          *     'main' => 'file1.js'
 176          * ]
 177          *
 178          * @param ResourceLoaderContext $context
 179          * @return string|array JavaScript code (string), or multi-file structure described above (array)
 180          */
 181         public function getScript( ResourceLoaderContext $context ) {
 182                 // Stub, override expected
 183                 return '';
 184         }
 185
 186         /**
 187          * Takes named templates by the module and returns an array mapping.
 188          *
 189          * @return string[] Array of templates mapping template alias to content
 190          */
 191         public function getTemplates() {
 192                 // Stub, override expected.
 193                 return [];
 194         }
 195
 196         /**
 197          * @return Config
 198          * @since 1.24
 199          */
 200         public function getConfig() {
 201                 if ( $this->config === null ) {
 202                         // Ugh, fall back to default
 203                         $this->config = MediaWikiServices::getInstance()->getMainConfig();
 204                 }
 205
 206                 return $this->config;
 207         }
 208
 209         /**
 210          * @param Config $config
 211          * @since 1.24
 212          */
 213         public function setConfig( Config $config ) {
 214                 $this->config = $config;
 215         }
 216
 217         /**
 218          * @since 1.27
 219          * @param LoggerInterface $logger
 220          */
 221         public function setLogger( LoggerInterface $logger ) {
 222                 $this->logger = $logger;
 223         }
 224
 225         /**
 226          * @since 1.27
 227          * @return LoggerInterface
 228          */
 229         protected function getLogger() {
 230                 if ( !$this->logger ) {
 231                         $this->logger = new NullLogger();
 232                 }
 233                 return $this->logger;
 234         }
 235
 236         /**
 237          * Get the URL or URLs to load for this module's JS in debug mode.
 238          * The default behavior is to return a load.php?only=scripts URL for
 239          * the module, but file-based modules will want to override this to
 240          * load the files directly.
 241          *
 242          * This function is called only when 1) we're in debug mode, 2) there
 243          * is no only= parameter and 3) supportsURLLoading() returns true.
 244          * #2 is important to prevent an infinite loop, therefore this function
 245          * MUST return either an only= URL or a non-load.php URL.
 246          *
 247          * @param ResourceLoaderContext $context
 248          * @return array Array of URLs
 249          */
 250         public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
 251                 $resourceLoader = $context->getResourceLoader();
 252                 $derivative = new DerivativeResourceLoaderContext( $context );
 253                 $derivative->setModules( [ $this->getName() ] );
 254                 $derivative->setOnly( 'scripts' );
 255                 $derivative->setDebug( true );
 256
 257                 $url = $resourceLoader->createLoaderURL(
 258                         $this->getSource(),
 259                         $derivative
 260                 );
 261
 262                 return [ $url ];
 263         }
 264
 265         /**
 266          * Whether this module supports URL loading. If this function returns false,
 267          * getScript() will be used even in cases (debug mode, no only param) where
 268          * getScriptURLsForDebug() would normally be used instead.
 269          * @return bool
 270          */
 271         public function supportsURLLoading() {
 272                 return true;
 273         }
 274
 275         /**
 276          * Get all CSS for this module for a given skin.
 277          *
 278          * @param ResourceLoaderContext $context
 279          * @return array List of CSS strings or array of CSS strings keyed by media type.
 280          *  like [ 'screen' => '.foo { width: 0 }' ];
 281          *  or [ 'screen' => [ '.foo { width: 0 }' ] ];
 282          */
 283         public function getStyles( ResourceLoaderContext $context ) {
 284                 // Stub, override expected
 285                 return [];
 286         }
 287
 288         /**
 289          * Get the URL or URLs to load for this module's CSS in debug mode.
 290          * The default behavior is to return a load.php?only=styles URL for
 291          * the module, but file-based modules will want to override this to
 292          * load the files directly. See also getScriptURLsForDebug()
 293          *
 294          * @param ResourceLoaderContext $context
 295          * @return array [ mediaType => [ URL1, URL2, ... ], ... ]
 296          */
 297         public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
 298                 $resourceLoader = $context->getResourceLoader();
 299                 $derivative = new DerivativeResourceLoaderContext( $context );
 300                 $derivative->setModules( [ $this->getName() ] );
 301                 $derivative->setOnly( 'styles' );
 302                 $derivative->setDebug( true );
 303
 304                 $url = $resourceLoader->createLoaderURL(
 305                         $this->getSource(),
 306                         $derivative
 307                 );
 308
 309                 return [ 'all' => [ $url ] ];
 310         }
 311
 312         /**
 313          * Get the messages needed for this module.
 314          *
 315          * To get a JSON blob with messages, use MessageBlobStore::get()
 316          *
 317          * @return array List of message keys. Keys may occur more than once
 318          */
 319         public function getMessages() {
 320                 // Stub, override expected
 321                 return [];
 322         }
 323
 324         /**
 325          * Get the group this module is in.
 326          *
 327          * @return string Group name
 328          */
 329         public function getGroup() {
 330                 // Stub, override expected
 331                 return null;
 332         }
 333
 334         /**
 335          * Get the source of this module. Should only be overridden for foreign modules.
 336          *
 337          * @return string Source name, 'local' for local modules
 338          */
 339         public function getSource() {
 340                 // Stub, override expected
 341                 return 'local';
 342         }
 343
 344         /**
 345          * Get a list of modules this module depends on.
 346          *
 347          * Dependency information is taken into account when loading a module
 348          * on the client side.
 349          *
 350          * Note: It is expected that $context will be made non-optional in the near
 351          * future.
 352          *
 353          * @param ResourceLoaderContext|null $context
 354          * @return array List of module names as strings
 355          */
 356         public function getDependencies( ResourceLoaderContext $context = null ) {
 357                 // Stub, override expected
 358                 return [];
 359         }
 360
 361         /**
 362          * Get target(s) for the module, eg ['desktop'] or ['desktop', 'mobile']
 363          *
 364          * @return array Array of strings
 365          */
 366         public function getTargets() {
 367                 return $this->targets;
 368         }
 369
 370         /**
 371          * Get the module's load type.
 372          *
 373          * @since 1.28
 374          * @return string ResourceLoaderModule LOAD_* constant
 375          */
 376         public function getType() {
 377                 return self::LOAD_GENERAL;
 378         }
 379
 380         /**
 381          * Get the skip function.
 382          *
 383          * Modules that provide fallback functionality can provide a "skip function". This
 384          * function, if provided, will be passed along to the module registry on the client.
 385          * When this module is loaded (either directly or as a dependency of another module),
 386          * then this function is executed first. If the function returns true, the module will
 387          * instantly be considered "ready" without requesting the associated module resources.
 388          *
 389          * The value returned here must be valid javascript for execution in a private function.
 390          * It must not contain the "function () {" and "}" wrapper though.
 391          *
 392          * @return string|null A JavaScript function body returning a boolean value, or null
 393          */
 394         public function getSkipFunction() {
 395                 return null;
 396         }
 397
 398         /**
 399          * Get the files this module depends on indirectly for a given skin.
 400          *
 401          * These are only image files referenced by the module's stylesheet.
 402          *
 403          * @param ResourceLoaderContext $context
 404          * @return array List of files
 405          */
 406         protected function getFileDependencies( ResourceLoaderContext $context ) {
 407                 $vary = self::getVary( $context );
 408
 409                 // Try in-object cache first
 410                 if ( !isset( $this->fileDeps[$vary] ) ) {
 411                         $dbr = wfGetDB( DB_REPLICA );
 412                         $deps = $dbr->selectField( 'module_deps',
 413                                 'md_deps',
 414                                 [
 415                                         'md_module' => $this->getName(),
 416                                         'md_skin' => $vary,
 417                                 ],
 418                                 __METHOD__
 419                         );
 420
 421                         if ( !is_null( $deps ) ) {
 422                                 $this->fileDeps[$vary] = self::expandRelativePaths(
 423                                         (array)json_decode( $deps, true )
 424                                 );
 425                         } else {
 426                                 $this->fileDeps[$vary] = [];
 427                         }
 428                 }
 429                 return $this->fileDeps[$vary];
 430         }
 431
 432         /**
 433          * Set in-object cache for file dependencies.
 434          *
 435          * This is used to retrieve data in batches. See ResourceLoader::preloadModuleInfo().
 436          * To save the data, use saveFileDependencies().
 437          *
 438          * @param ResourceLoaderContext $context
 439          * @param string[] $files Array of file names
 440          */
 441         public function setFileDependencies( ResourceLoaderContext $context, $files ) {
 442                 $vary = self::getVary( $context );
 443                 $this->fileDeps[$vary] = $files;
 444         }
 445
 446         /**
 447          * Set the files this module depends on indirectly for a given skin.
 448          *
 449          * @since 1.27
 450          * @param ResourceLoaderContext $context
 451          * @param array $localFileRefs List of files
 452          */
 453         protected function saveFileDependencies( ResourceLoaderContext $context, $localFileRefs ) {
 454                 try {
 455                         // Related bugs and performance considerations:
 456                         // 1. Don't needlessly change the database value with the same list in a
 457                         //    different order or with duplicates.
 458                         // 2. Use relative paths to avoid ghost entries when $IP changes. (T111481)
 459                         // 3. Don't needlessly replace the database with the same value
 460                         //    just because $IP changed (e.g. when upgrading a wiki).
 461                         // 4. Don't create an endless replace loop on every request for this
 462                         //    module when '../' is used anywhere. Even though both are expanded
 463                         //    (one expanded by getFileDependencies from the DB, the other is
 464                         //    still raw as originally read by RL), the latter has not
 465                         //    been normalized yet.
 466
 467                         // Normalise
 468                         $localFileRefs = array_values( array_unique( $localFileRefs ) );
 469                         sort( $localFileRefs );
 470                         $localPaths = self::getRelativePaths( $localFileRefs );
 471                         $storedPaths = self::getRelativePaths( $this->getFileDependencies( $context ) );
 472
 473                         if ( $localPaths === $storedPaths ) {
 474                                 // Unchanged. Avoid needless database query (especially master conn!).
 475                                 return;
 476                         }
 477
 478                         // The file deps list has changed, we want to update it.
 479                         $vary = self::getVary( $context );
 480                         $cache = ObjectCache::getLocalClusterInstance();
 481                         $key = $cache->makeKey( __METHOD__, $this->getName(), $vary );
 482                         $scopeLock = $cache->getScopedLock( $key, 0 );
 483                         if ( !$scopeLock ) {
 484                                 // Another request appears to be doing this update already.
 485                                 // Avoid write slams (T124649).
 486                                 return;
 487                         }
 488
 489                         // No needless escaping as this isn't HTML output.
 490                         // Only stored in the database and parsed in PHP.
 491                         $deps = json_encode( $localPaths, JSON_UNESCAPED_SLASHES );
 492                         $dbw = wfGetDB( DB_MASTER );
 493                         $dbw->upsert( 'module_deps',
 494                                 [
 495                                         'md_module' => $this->getName(),
 496                                         'md_skin' => $vary,
 497                                         'md_deps' => $deps,
 498                                 ],
 499                                 [ [ 'md_module', 'md_skin' ] ],
 500                                 [
 501                                         'md_deps' => $deps,
 502                                 ],
 503                                 __METHOD__
 504                         );
 505
 506                         if ( $dbw->trxLevel() ) {
 507                                 $dbw->onTransactionResolution(
 508                                         function () use ( &$scopeLock ) {
 509                                                 ScopedCallback::consume( $scopeLock ); // release after commit
 510                                         },
 511                                         __METHOD__
 512                                 );
 513                         }
 514                 } catch ( Exception $e ) {
 515                         // Probably a DB failure. Either the read query from getFileDependencies(),
 516                         // or the write query above.
 517                         wfDebugLog( 'resourceloader', __METHOD__ . ": failed to update DB: $e" );
 518                 }
 519         }
 520
 521         /**
 522          * Make file paths relative to MediaWiki directory.
 523          *
 524          * This is used to make file paths safe for storing in a database without the paths
 525          * becoming stale or incorrect when MediaWiki is moved or upgraded (T111481).
 526          *
 527          * @since 1.27
 528          * @param array $filePaths
 529          * @return array
 530          */
 531         public static function getRelativePaths( array $filePaths ) {
 532                 global $IP;
 533                 return array_map( function ( $path ) use ( $IP ) {
 534                         return RelPath::getRelativePath( $path, $IP );
 535                 }, $filePaths );
 536         }
 537
 538         /**
 539          * Expand directories relative to $IP.
 540          *
 541          * @since 1.27
 542          * @param array $filePaths
 543          * @return array
 544          */
 545         public static function expandRelativePaths( array $filePaths ) {
 546                 global $IP;
 547                 return array_map( function ( $path ) use ( $IP ) {
 548                         return RelPath::joinPath( $IP, $path );
 549                 }, $filePaths );
 550         }
 551
 552         /**
 553          * Get the hash of the message blob.
 554          *
 555          * @since 1.27
 556          * @param ResourceLoaderContext $context
 557          * @return string|null JSON blob or null if module has no messages
 558          */
 559         protected function getMessageBlob( ResourceLoaderContext $context ) {
 560                 if ( !$this->getMessages() ) {
 561                         // Don't bother consulting MessageBlobStore
 562                         return null;
 563                 }
 564                 // Message blobs may only vary language, not by context keys
 565                 $lang = $context->getLanguage();
 566                 if ( !isset( $this->msgBlobs[$lang] ) ) {
 567                         $this->getLogger()->warning( 'Message blob for {module} should have been preloaded', [
 568                                 'module' => $this->getName(),
 569                         ] );
 570                         $store = $context->getResourceLoader()->getMessageBlobStore();
 571                         $this->msgBlobs[$lang] = $store->getBlob( $this, $lang );
 572                 }
 573                 return $this->msgBlobs[$lang];
 574         }
 575
 576         /**
 577          * Set in-object cache for message blobs.
 578          *
 579          * Used to allow fetching of message blobs in batches. See ResourceLoader::preloadModuleInfo().
 580          *
 581          * @since 1.27
 582          * @param string|null $blob JSON blob or null
 583          * @param string $lang Language code
 584          */
 585         public function setMessageBlob( $blob, $lang ) {
 586                 $this->msgBlobs[$lang] = $blob;
 587         }
 588
 589         /**
 590          * Get headers to send as part of a module web response.
 591          *
 592          * It is not supported to send headers through this method that are
 593          * required to be unique or otherwise sent once in an HTTP response
 594          * because clients may make batch requests for multiple modules (as
 595          * is the default behaviour for ResourceLoader clients).
 596          *
 597          * For exclusive or aggregated headers, see ResourceLoader::sendResponseHeaders().
 598          *
 599          * @since 1.30
 600          * @param ResourceLoaderContext $context
 601          * @return string[] Array of HTTP response headers
 602          */
 603         final public function getHeaders( ResourceLoaderContext $context ) {
 604                 $headers = [];
 605
 606                 $formattedLinks = [];
 607                 foreach ( $this->getPreloadLinks( $context ) as $url => $attribs ) {
 608                         $link = "<{$url}>;rel=preload";
 609                         foreach ( $attribs as $key => $val ) {
 610                                 $link .= ";{$key}={$val}";
 611                         }
 612                         $formattedLinks[] = $link;
 613                 }
 614                 if ( $formattedLinks ) {
 615                         $headers[] = 'Link: ' . implode( ',', $formattedLinks );
 616                 }
 617
 618                 return $headers;
 619         }
 620
 621         /**
 622          * Get a list of resources that web browsers may preload.
 623          *
 624          * Behaviour of rel=preload link is specified at <https://www.w3.org/TR/preload/>.
 625          *
 626          * Use case for ResourceLoader originally part of T164299.
 627          *
 628          * @par Example
 629          * @code
 630          *     protected function getPreloadLinks() {
 631          *         return [
 632          *             'https://example.org/script.js' => [ 'as' => 'script' ],
 633          *             'https://example.org/image.png' => [ 'as' => 'image' ],
 634          *         ];
 635          *     }
 636          * @endcode
 637          *
 638          * @par Example using HiDPI image variants
 639          * @code
 640          *     protected function getPreloadLinks() {
 641          *         return [
 642          *             'https://example.org/logo.png' => [
 643          *                 'as' => 'image',
 644          *                 'media' => 'not all and (min-resolution: 2dppx)',
 645          *             ],
 646          *             'https://example.org/logo@2x.png' => [
 647          *                 'as' => 'image',
 648          *                 'media' => '(min-resolution: 2dppx)',
 649          *             ],
 650          *         ];
 651          *     }
 652          * @endcode
 653          *
 654          * @see ResourceLoaderModule::getHeaders
 655          * @since 1.30
 656          * @param ResourceLoaderContext $context
 657          * @return array Keyed by url, values must be an array containing
 658          *  at least an 'as' key. Optionally a 'media' key as well.
 659          */
 660         protected function getPreloadLinks( ResourceLoaderContext $context ) {
 661                 return [];
 662         }
 663
 664         /**
 665          * Get module-specific LESS variables, if any.
 666          *
 667          * @since 1.27
 668          * @param ResourceLoaderContext $context
 669          * @return array Module-specific LESS variables.
 670          */
 671         protected function getLessVars( ResourceLoaderContext $context ) {
 672                 return [];
 673         }
 674
 675         /**
 676          * Get an array of this module's resources. Ready for serving to the web.
 677          *
 678          * @since 1.26
 679          * @param ResourceLoaderContext $context
 680          * @return array
 681          */
 682         public function getModuleContent( ResourceLoaderContext $context ) {
 683                 $contextHash = $context->getHash();
 684                 // Cache this expensive operation. This calls builds the scripts, styles, and messages
 685                 // content which typically involves filesystem and/or database access.
 686                 if ( !array_key_exists( $contextHash, $this->contents ) ) {
 687                         $this->contents[$contextHash] = $this->buildContent( $context );
 688                 }
 689                 return $this->contents[$contextHash];
 690         }
 691
 692         /**
 693          * Bundle all resources attached to this module into an array.
 694          *
 695          * @since 1.26
 696          * @param ResourceLoaderContext $context
 697          * @return array
 698          */
 699         final protected function buildContent( ResourceLoaderContext $context ) {
 700                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 701                 $statStart = microtime( true );
 702
 703                 // This MUST build both scripts and styles, regardless of whether $context->getOnly()
 704                 // is 'scripts' or 'styles' because the result is used by getVersionHash which
 705                 // must be consistent regardless of the 'only' filter on the current request.
 706                 // Also, when introducing new module content resources (e.g. templates, headers),
 707                 // these should only be included in the array when they are non-empty so that
 708                 // existing modules not using them do not get their cache invalidated.
 709                 $content = [];
 710
 711                 // Scripts
 712                 // If we are in debug mode, we'll want to return an array of URLs if possible
 713                 // However, we can't do this if the module doesn't support it.
 714                 // We also can't do this if there is an only= parameter, because we have to give
 715                 // the module a way to return a load.php URL without causing an infinite loop
 716                 if ( $context->getDebug() && !$context->getOnly() && $this->supportsURLLoading() ) {
 717                         $scripts = $this->getScriptURLsForDebug( $context );
 718                 } else {
 719                         $scripts = $this->getScript( $context );
 720                         // Make the script safe to concatenate by making sure there is at least one
 721                         // trailing new line at the end of the content. Previously, this looked for
 722                         // a semi-colon instead, but that breaks concatenation if the semicolon
 723                         // is inside a comment like "// foo();". Instead, simply use a
 724                         // line break as separator which matches JavaScript native logic for implicitly
 725                         // ending statements even if a semi-colon is missing.
 726                         // Bugs: T29054, T162719.
 727                         if ( is_string( $scripts )
 728                                 && strlen( $scripts )
 729                                 && substr( $scripts, -1 ) !== "\n"
 730                         ) {
 731                                 $scripts .= "\n";
 732                         }
 733                 }
 734                 $content['scripts'] = $scripts;
 735
 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' => ResourceLoader::makeCombinedStyles( $stylePairs )
 769                                 ];
 770                         }
 771                 }
 772                 $content['styles'] = $styles;
 773
 774                 // Messages
 775                 $blob = $this->getMessageBlob( $context );
 776                 if ( $blob ) {
 777                         $content['messagesBlob'] = $blob;
 778                 }
 779
 780                 $templates = $this->getTemplates();
 781                 if ( $templates ) {
 782                         $content['templates'] = $templates;
 783                 }
 784
 785                 $headers = $this->getHeaders( $context );
 786                 if ( $headers ) {
 787                         $content['headers'] = $headers;
 788                 }
 789
 790                 $statTiming = microtime( true ) - $statStart;
 791                 $statName = strtr( $this->getName(), '.', '_' );
 792                 $stats->timing( "resourceloader_build.all", 1000 * $statTiming );
 793                 $stats->timing( "resourceloader_build.$statName", 1000 * $statTiming );
 794
 795                 return $content;
 796         }
 797
 798         /**
 799          * Get a string identifying the current version of this module in a given context.
 800          *
 801          * Whenever anything happens that changes the module's response (e.g. scripts, styles, and
 802          * messages) this value must change. This value is used to store module responses in cache.
 803          * (Both client-side and server-side.)
 804          *
 805          * It is not recommended to override this directly. Use getDefinitionSummary() instead.
 806          * If overridden, one must call the parent getVersionHash(), append data and re-hash.
 807          *
 808          * This method should be quick because it is frequently run by ResourceLoaderStartUpModule to
 809          * propagate changes to the client and effectively invalidate cache.
 810          *
 811          * @since 1.26
 812          * @param ResourceLoaderContext $context
 813          * @return string Hash (should use ResourceLoader::makeHash)
 814          */
 815         public function getVersionHash( ResourceLoaderContext $context ) {
 816                 // Cache this somewhat expensive operation. Especially because some classes
 817                 // (e.g. startup module) iterate more than once over all modules to get versions.
 818                 $contextHash = $context->getHash();
 819                 if ( !array_key_exists( $contextHash, $this->versionHash ) ) {
 820                         if ( $this->enableModuleContentVersion() ) {
 821                                 // Detect changes directly by hashing the module contents.
 822                                 $str = json_encode( $this->getModuleContent( $context ) );
 823                         } else {
 824                                 // Infer changes based on definition and other metrics
 825                                 $summary = $this->getDefinitionSummary( $context );
 826                                 if ( !isset( $summary['_class'] ) ) {
 827                                         throw new LogicException( 'getDefinitionSummary must call parent method' );
 828                                 }
 829                                 $str = json_encode( $summary );
 830                         }
 831
 832                         $this->versionHash[$contextHash] = ResourceLoader::makeHash( $str );
 833                 }
 834                 return $this->versionHash[$contextHash];
 835         }
 836
 837         /**
 838          * Whether to generate version hash based on module content.
 839          *
 840          * If a module requires database or file system access to build the module
 841          * content, consider disabling this in favour of manually tracking relevant
 842          * aspects in getDefinitionSummary(). See getVersionHash() for how this is used.
 843          *
 844          * @return bool
 845          */
 846         public function enableModuleContentVersion() {
 847                 return false;
 848         }
 849
 850         /**
 851          * Get the definition summary for this module.
 852          *
 853          * This is the method subclasses are recommended to use to track values in their
 854          * version hash. Call this in getVersionHash() and pass it to e.g. json_encode.
 855          *
 856          * Subclasses must call the parent getDefinitionSummary() and build on that.
 857          * It is recommended that each subclass appends its own new array. This prevents
 858          * clashes or accidental overwrites of existing keys and gives each subclass
 859          * its own scope for simple array keys.
 860          *
 861          * @code
 862          *     $summary = parent::getDefinitionSummary( $context );
 863          *     $summary[] = [
 864          *         'foo' => 123,
 865          *         'bar' => 'quux',
 866          *     ];
 867          *     return $summary;
 868          * @endcode
 869          *
 870          * Return an array containing values from all significant properties of this
 871          * module's definition.
 872          *
 873          * Be careful not to normalise too much. Especially preserve the order of things
 874          * that carry significance in getScript and getStyles (T39812).
 875          *
 876          * Avoid including things that are insiginificant (e.g. order of message keys is
 877          * insignificant and should be sorted to avoid unnecessary cache invalidation).
 878          *
 879          * This data structure must exclusively contain arrays and scalars as values (avoid
 880          * object instances) to allow simple serialisation using json_encode.
 881          *
 882          * If modules have a hash or timestamp from another source, that may be incuded as-is.
 883          *
 884          * A number of utility methods are available to help you gather data. These are not
 885          * called by default and must be included by the subclass' getDefinitionSummary().
 886          *
 887          * - getMessageBlob()
 888          *
 889          * @since 1.23
 890          * @param ResourceLoaderContext $context
 891          * @return array|null
 892          */
 893         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 894                 return [
 895                         '_class' => static::class,
 896                         // Make sure that when filter cache for minification is invalidated,
 897                         // we also change the HTTP urls and mw.loader.store keys (T176884).
 898                         '_cacheVersion' => ResourceLoader::CACHE_VERSION,
 899                 ];
 900         }
 901
 902         /**
 903          * Check whether this module is known to be empty. If a child class
 904          * has an easy and cheap way to determine that this module is
 905          * definitely going to be empty, it should override this method to
 906          * return true in that case. Callers may optimize the request for this
 907          * module away if this function returns true.
 908          * @param ResourceLoaderContext $context
 909          * @return bool
 910          */
 911         public function isKnownEmpty( ResourceLoaderContext $context ) {
 912                 return false;
 913         }
 914
 915         /**
 916          * Check whether this module should be embeded rather than linked
 917          *
 918          * Modules returning true here will be embedded rather than loaded by
 919          * ResourceLoaderClientHtml.
 920          *
 921          * @since 1.30
 922          * @param ResourceLoaderContext $context
 923          * @return bool
 924          */
 925         public function shouldEmbedModule( ResourceLoaderContext $context ) {
 926                 return $this->getGroup() === 'private';
 927         }
 928
 929         /** @var JSParser Lazy-initialized; use self::javaScriptParser() */
 930         private static $jsParser;
 931         private static $parseCacheVersion = 1;
 932
 933         /**
 934          * Validate a given script file; if valid returns the original source.
 935          * If invalid, returns replacement JS source that throws an exception.
 936          *
 937          * @param string $fileName
 938          * @param string $contents
 939          * @return string JS with the original, or a replacement error
 940          */
 941         protected function validateScriptFile( $fileName, $contents ) {
 942                 if ( !$this->getConfig()->get( 'ResourceLoaderValidateJS' ) ) {
 943                         return $contents;
 944                 }
 945                 $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
 946                 return $cache->getWithSetCallback(
 947                         $cache->makeGlobalKey(
 948                                 'resourceloader-jsparse',
 949                                 self::$parseCacheVersion,
 950                                 md5( $contents ),
 951                                 $fileName
 952                         ),
 953                         $cache::TTL_WEEK,
 954                         function () use ( $contents, $fileName ) {
 955                                 $parser = self::javaScriptParser();
 956                                 $err = null;
 957                                 try {
 958                                         AtEase::suppressWarnings();
 959                                         $parser->parse( $contents, $fileName, 1 );
 960                                 } catch ( Exception $e ) {
 961                                         $err = $e;
 962                                 } finally {
 963                                         AtEase::restoreWarnings();
 964                                 }
 965                                 if ( $err ) {
 966                                         // Send the error to the browser console client-side.
 967                                         // By returning this as replacement for the actual script,
 968                                         // we ensure modules are safe to load in a batch request,
 969                                         // without causing other unrelated modules to break.
 970                                         return 'mw.log.error(' .
 971                                                 Xml::encodeJsVar( 'JavaScript parse error: ' . $err->getMessage() ) .
 972                                                 ');';
 973                                 }
 974                                 return $contents;
 975                         }
 976                 );
 977         }
 978
 979         /**
 980          * @return JSParser
 981          */
 982         protected static function javaScriptParser() {
 983                 if ( !self::$jsParser ) {
 984                         self::$jsParser = new JSParser();
 985                 }
 986                 return self::$jsParser;
 987         }
 988
 989         /**
 990          * Safe version of filemtime(), which doesn't throw a PHP warning if the file doesn't exist.
 991          * Defaults to 1.
 992          *
 993          * @param string $filePath File path
 994          * @return int UNIX timestamp
 995          */
 996         protected static function safeFilemtime( $filePath ) {
 997                 AtEase::suppressWarnings();
 998                 $mtime = filemtime( $filePath ) ?: 1;
 999                 AtEase::restoreWarnings();
1000                 return $mtime;
1001         }
1002
1003         /**
1004          * Compute a non-cryptographic string hash of a file's contents.
1005          * If the file does not exist or cannot be read, returns an empty string.
1006          *
1007          * @since 1.26 Uses MD4 instead of SHA1.
1008          * @param string $filePath File path
1009          * @return string Hash
1010          */
1011         protected static function safeFileHash( $filePath ) {
1012                 return FileContentsHasher::getFileContentsHash( $filePath );
1013         }
1014
1015         /**
1016          * Get vary string.
1017          *
1018          * @internal For internal use only.
1019          * @param ResourceLoaderContext $context
1020          * @return string Vary string
1021          */
1022         public static function getVary( ResourceLoaderContext $context ) {
1023                 return implode( '|', [
1024                         $context->getSkin(),
1025                         $context->getLanguage(),
1026                 ] );
1027         }
1028 }