includes/resourceloader/ResourceLoaderModule.php

   1 <?php
   2 /**
   3  * Abstraction for ResourceLoader modules.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Trevor Parscal
  22  * @author Roan Kattouw
  23  */
  24
  25 use MediaWiki\MediaWikiServices;
  26 use Psr\Log\LoggerAwareInterface;
  27 use Psr\Log\LoggerInterface;
  28 use Psr\Log\NullLogger;
  29 use Wikimedia\RelPath;
  30 use Wikimedia\ScopedCallback;
  31
  32 /**
  33  * Abstraction for ResourceLoader modules, with name registration and maxage functionality.
  34  */
  35 abstract class ResourceLoaderModule implements LoggerAwareInterface {
  36         # Type of resource
  37         const TYPE_SCRIPTS = 'scripts';
  38         const TYPE_STYLES = 'styles';
  39         const TYPE_COMBINED = 'combined';
  40
  41         # Desired load type
  42         // Module only has styles (loaded via <style> or <link rel=stylesheet>)
  43         const LOAD_STYLES = 'styles';
  44         // Module may have other resources (loaded via mw.loader from a script)
  45         const LOAD_GENERAL = 'general';
  46
  47         # sitewide core module like a skin file or jQuery component
  48         const ORIGIN_CORE_SITEWIDE = 1;
  49
  50         # per-user module generated by the software
  51         const ORIGIN_CORE_INDIVIDUAL = 2;
  52
  53         # sitewide module generated from user-editable files, like MediaWiki:Common.js, or
  54         # modules accessible to multiple users, such as those generated by the Gadgets extension.
  55         const ORIGIN_USER_SITEWIDE = 3;
  56
  57         # per-user module generated from user-editable files, like User:Me/vector.js
  58         const ORIGIN_USER_INDIVIDUAL = 4;
  59
  60         # an access constant; make sure this is kept as the largest number in this group
  61         const ORIGIN_ALL = 10;
  62
  63         # script and style modules form a hierarchy of trustworthiness, with core modules like
  64         # skins and jQuery as most trustworthy, and user scripts as least trustworthy.  We can
  65         # limit the types of scripts and styles we allow to load on, say, sensitive special
  66         # pages like Special:UserLogin and Special:Preferences
  67         protected $origin = self::ORIGIN_CORE_SITEWIDE;
  68
  69         protected $name = null;
  70         protected $targets = [ 'desktop' ];
  71
  72         // In-object cache for file dependencies
  73         protected $fileDeps = [];
  74         // In-object cache for message blob (keyed by language)
  75         protected $msgBlobs = [];
  76         // In-object cache for version hash
  77         protected $versionHash = [];
  78         // In-object cache for module content
  79         protected $contents = [];
  80
  81         /**
  82          * @var Config
  83          */
  84         protected $config;
  85
  86         /**
  87          * @var array|bool
  88          */
  89         protected $deprecated = false;
  90
  91         /**
  92          * @var LoggerInterface
  93          */
  94         protected $logger;
  95
  96         /**
  97          * Get this module's name. This is set when the module is registered
  98          * with ResourceLoader::register()
  99          *
 100          * @return string|null Name (string) or null if no name was set
 101          */
 102         public function getName() {
 103                 return $this->name;
 104         }
 105
 106         /**
 107          * Set this module's name. This is called by ResourceLoader::register()
 108          * when registering the module. Other code should not call this.
 109          *
 110          * @param string $name
 111          */
 112         public function setName( $name ) {
 113                 $this->name = $name;
 114         }
 115
 116         /**
 117          * Get this module's origin. This is set when the module is registered
 118          * with ResourceLoader::register()
 119          *
 120          * @return int ResourceLoaderModule class constant, the subclass default
 121          *     if not set manually
 122          */
 123         public function getOrigin() {
 124                 return $this->origin;
 125         }
 126
 127         /**
 128          * @param ResourceLoaderContext $context
 129          * @return bool
 130          */
 131         public function getFlip( $context ) {
 132                 global $wgContLang;
 133
 134                 return $wgContLang->getDir() !== $context->getDirection();
 135         }
 136
 137         /**
 138          * Get JS representing deprecation information for the current module if available
 139          *
 140          * @return string JavaScript code
 141          */
 142         protected function getDeprecationInformation() {
 143                 $deprecationInfo = $this->deprecated;
 144                 if ( $deprecationInfo ) {
 145                         $name = $this->getName();
 146                         $warning = 'This page is using the deprecated ResourceLoader module "' . $name . '".';
 147                         if ( is_string( $deprecationInfo ) ) {
 148                                 $warning .= "\n" . $deprecationInfo;
 149                         }
 150                         return Xml::encodeJsCall(
 151                                 'mw.log.warn',
 152                                 [ $warning ]
 153                         );
 154                 } else {
 155                         return '';
 156                 }
 157         }
 158
 159         /**
 160          * Get all JS for this module for a given language and skin.
 161          * Includes all relevant JS except loader scripts.
 162          *
 163          * @param ResourceLoaderContext $context
 164          * @return string JavaScript code
 165          */
 166         public function getScript( ResourceLoaderContext $context ) {
 167                 // Stub, override expected
 168                 return '';
 169         }
 170
 171         /**
 172          * Takes named templates by the module and returns an array mapping.
 173          *
 174          * @return array of templates mapping template alias to content
 175          */
 176         public function getTemplates() {
 177                 // Stub, override expected.
 178                 return [];
 179         }
 180
 181         /**
 182          * @return Config
 183          * @since 1.24
 184          */
 185         public function getConfig() {
 186                 if ( $this->config === null ) {
 187                         // Ugh, fall back to default
 188                         $this->config = MediaWikiServices::getInstance()->getMainConfig();
 189                 }
 190
 191                 return $this->config;
 192         }
 193
 194         /**
 195          * @param Config $config
 196          * @since 1.24
 197          */
 198         public function setConfig( Config $config ) {
 199                 $this->config = $config;
 200         }
 201
 202         /**
 203          * @since 1.27
 204          * @param LoggerInterface $logger
 205          * @return null
 206          */
 207         public function setLogger( LoggerInterface $logger ) {
 208                 $this->logger = $logger;
 209         }
 210
 211         /**
 212          * @since 1.27
 213          * @return LoggerInterface
 214          */
 215         protected function getLogger() {
 216                 if ( !$this->logger ) {
 217                         $this->logger = new NullLogger();
 218                 }
 219                 return $this->logger;
 220         }
 221
 222         /**
 223          * Get the URL or URLs to load for this module's JS in debug mode.
 224          * The default behavior is to return a load.php?only=scripts URL for
 225          * the module, but file-based modules will want to override this to
 226          * load the files directly.
 227          *
 228          * This function is called only when 1) we're in debug mode, 2) there
 229          * is no only= parameter and 3) supportsURLLoading() returns true.
 230          * #2 is important to prevent an infinite loop, therefore this function
 231          * MUST return either an only= URL or a non-load.php URL.
 232          *
 233          * @param ResourceLoaderContext $context
 234          * @return array Array of URLs
 235          */
 236         public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
 237                 $resourceLoader = $context->getResourceLoader();
 238                 $derivative = new DerivativeResourceLoaderContext( $context );
 239                 $derivative->setModules( [ $this->getName() ] );
 240                 $derivative->setOnly( 'scripts' );
 241                 $derivative->setDebug( true );
 242
 243                 $url = $resourceLoader->createLoaderURL(
 244                         $this->getSource(),
 245                         $derivative
 246                 );
 247
 248                 return [ $url ];
 249         }
 250
 251         /**
 252          * Whether this module supports URL loading. If this function returns false,
 253          * getScript() will be used even in cases (debug mode, no only param) where
 254          * getScriptURLsForDebug() would normally be used instead.
 255          * @return bool
 256          */
 257         public function supportsURLLoading() {
 258                 return true;
 259         }
 260
 261         /**
 262          * Get all CSS for this module for a given skin.
 263          *
 264          * @param ResourceLoaderContext $context
 265          * @return array List of CSS strings or array of CSS strings keyed by media type.
 266          *  like [ 'screen' => '.foo { width: 0 }' ];
 267          *  or [ 'screen' => [ '.foo { width: 0 }' ] ];
 268          */
 269         public function getStyles( ResourceLoaderContext $context ) {
 270                 // Stub, override expected
 271                 return [];
 272         }
 273
 274         /**
 275          * Get the URL or URLs to load for this module's CSS in debug mode.
 276          * The default behavior is to return a load.php?only=styles URL for
 277          * the module, but file-based modules will want to override this to
 278          * load the files directly. See also getScriptURLsForDebug()
 279          *
 280          * @param ResourceLoaderContext $context
 281          * @return array [ mediaType => [ URL1, URL2, ... ], ... ]
 282          */
 283         public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
 284                 $resourceLoader = $context->getResourceLoader();
 285                 $derivative = new DerivativeResourceLoaderContext( $context );
 286                 $derivative->setModules( [ $this->getName() ] );
 287                 $derivative->setOnly( 'styles' );
 288                 $derivative->setDebug( true );
 289
 290                 $url = $resourceLoader->createLoaderURL(
 291                         $this->getSource(),
 292                         $derivative
 293                 );
 294
 295                 return [ 'all' => [ $url ] ];
 296         }
 297
 298         /**
 299          * Get the messages needed for this module.
 300          *
 301          * To get a JSON blob with messages, use MessageBlobStore::get()
 302          *
 303          * @return array List of message keys. Keys may occur more than once
 304          */
 305         public function getMessages() {
 306                 // Stub, override expected
 307                 return [];
 308         }
 309
 310         /**
 311          * Get the group this module is in.
 312          *
 313          * @return string Group name
 314          */
 315         public function getGroup() {
 316                 // Stub, override expected
 317                 return null;
 318         }
 319
 320         /**
 321          * Get the origin of this module. Should only be overridden for foreign modules.
 322          *
 323          * @return string Origin name, 'local' for local modules
 324          */
 325         public function getSource() {
 326                 // Stub, override expected
 327                 return 'local';
 328         }
 329
 330         /**
 331          * Whether this module's JS expects to work without the client-side ResourceLoader module.
 332          * Returning true from this function will prevent mw.loader.state() call from being
 333          * appended to the bottom of the script.
 334          *
 335          * @return bool
 336          */
 337         public function isRaw() {
 338                 return false;
 339         }
 340
 341         /**
 342          * Get a list of modules this module depends on.
 343          *
 344          * Dependency information is taken into account when loading a module
 345          * on the client side.
 346          *
 347          * Note: It is expected that $context will be made non-optional in the near
 348          * future.
 349          *
 350          * @param ResourceLoaderContext $context
 351          * @return array List of module names as strings
 352          */
 353         public function getDependencies( ResourceLoaderContext $context = null ) {
 354                 // Stub, override expected
 355                 return [];
 356         }
 357
 358         /**
 359          * Get target(s) for the module, eg ['desktop'] or ['desktop', 'mobile']
 360          *
 361          * @return array Array of strings
 362          */
 363         public function getTargets() {
 364                 return $this->targets;
 365         }
 366
 367         /**
 368          * Get the module's load type.
 369          *
 370          * @since 1.28
 371          * @return string ResourceLoaderModule LOAD_* constant
 372          */
 373         public function getType() {
 374                 return self::LOAD_GENERAL;
 375         }
 376
 377         /**
 378          * Get the skip function.
 379          *
 380          * Modules that provide fallback functionality can provide a "skip function". This
 381          * function, if provided, will be passed along to the module registry on the client.
 382          * When this module is loaded (either directly or as a dependency of another module),
 383          * then this function is executed first. If the function returns true, the module will
 384          * instantly be considered "ready" without requesting the associated module resources.
 385          *
 386          * The value returned here must be valid javascript for execution in a private function.
 387          * It must not contain the "function () {" and "}" wrapper though.
 388          *
 389          * @return string|null A JavaScript function body returning a boolean value, or null
 390          */
 391         public function getSkipFunction() {
 392                 return null;
 393         }
 394
 395         /**
 396          * Get the files this module depends on indirectly for a given skin.
 397          *
 398          * These are only image files referenced by the module's stylesheet.
 399          *
 400          * @param ResourceLoaderContext $context
 401          * @return array List of files
 402          */
 403         protected function getFileDependencies( ResourceLoaderContext $context ) {
 404                 $vary = $context->getSkin() . '|' . $context->getLanguage();
 405
 406                 // Try in-object cache first
 407                 if ( !isset( $this->fileDeps[$vary] ) ) {
 408                         $dbr = wfGetDB( DB_REPLICA );
 409                         $deps = $dbr->selectField( 'module_deps',
 410                                 'md_deps',
 411                                 [
 412                                         'md_module' => $this->getName(),
 413                                         'md_skin' => $vary,
 414                                 ],
 415                                 __METHOD__
 416                         );
 417
 418                         if ( !is_null( $deps ) ) {
 419                                 $this->fileDeps[$vary] = self::expandRelativePaths(
 420                                         (array)FormatJson::decode( $deps, true )
 421                                 );
 422                         } else {
 423                                 $this->fileDeps[$vary] = [];
 424                         }
 425                 }
 426                 return $this->fileDeps[$vary];
 427         }
 428
 429         /**
 430          * Set in-object cache for file dependencies.
 431          *
 432          * This is used to retrieve data in batches. See ResourceLoader::preloadModuleInfo().
 433          * To save the data, use saveFileDependencies().
 434          *
 435          * @param ResourceLoaderContext $context
 436          * @param string[] $files Array of file names
 437          */
 438         public function setFileDependencies( ResourceLoaderContext $context, $files ) {
 439                 $vary = $context->getSkin() . '|' . $context->getLanguage();
 440                 $this->fileDeps[$vary] = $files;
 441         }
 442
 443         /**
 444          * Set the files this module depends on indirectly for a given skin.
 445          *
 446          * @since 1.27
 447          * @param ResourceLoaderContext $context
 448          * @param array $localFileRefs List of files
 449          */
 450         protected function saveFileDependencies( ResourceLoaderContext $context, $localFileRefs ) {
 451                 try {
 452                         // Related bugs and performance considerations:
 453                         // 1. Don't needlessly change the database value with the same list in a
 454                         //    different order or with duplicates.
 455                         // 2. Use relative paths to avoid ghost entries when $IP changes. (T111481)
 456                         // 3. Don't needlessly replace the database with the same value
 457                         //    just because $IP changed (e.g. when upgrading a wiki).
 458                         // 4. Don't create an endless replace loop on every request for this
 459                         //    module when '../' is used anywhere. Even though both are expanded
 460                         //    (one expanded by getFileDependencies from the DB, the other is
 461                         //    still raw as originally read by RL), the latter has not
 462                         //    been normalized yet.
 463
 464                         // Normalise
 465                         $localFileRefs = array_values( array_unique( $localFileRefs ) );
 466                         sort( $localFileRefs );
 467                         $localPaths = self::getRelativePaths( $localFileRefs );
 468
 469                         $storedPaths = self::getRelativePaths( $this->getFileDependencies( $context ) );
 470                         // If the list has been modified since last time we cached it, update the cache
 471                         if ( $localPaths !== $storedPaths ) {
 472                                 $vary = $context->getSkin() . '|' . $context->getLanguage();
 473                                 $cache = ObjectCache::getLocalClusterInstance();
 474                                 $key = $cache->makeKey( __METHOD__, $this->getName(), $vary );
 475                                 $scopeLock = $cache->getScopedLock( $key, 0 );
 476                                 if ( !$scopeLock ) {
 477                                         return; // T124649; avoid write slams
 478                                 }
 479
 480                                 $deps = FormatJson::encode( $localPaths );
 481                                 $dbw = wfGetDB( DB_MASTER );
 482                                 $dbw->upsert( 'module_deps',
 483                                         [
 484                                                 'md_module' => $this->getName(),
 485                                                 'md_skin' => $vary,
 486                                                 'md_deps' => $deps,
 487                                         ],
 488                                         [ 'md_module', 'md_skin' ],
 489                                         [
 490                                                 'md_deps' => $deps,
 491                                         ]
 492                                 );
 493
 494                                 if ( $dbw->trxLevel() ) {
 495                                         $dbw->onTransactionResolution(
 496                                                 function () use ( &$scopeLock ) {
 497                                                         ScopedCallback::consume( $scopeLock ); // release after commit
 498                                                 },
 499                                                 __METHOD__
 500                                         );
 501                                 }
 502                         }
 503                 } catch ( Exception $e ) {
 504                         wfDebugLog( 'resourceloader', __METHOD__ . ": failed to update DB: $e" );
 505                 }
 506         }
 507
 508         /**
 509          * Make file paths relative to MediaWiki directory.
 510          *
 511          * This is used to make file paths safe for storing in a database without the paths
 512          * becoming stale or incorrect when MediaWiki is moved or upgraded (T111481).
 513          *
 514          * @since 1.27
 515          * @param array $filePaths
 516          * @return array
 517          */
 518         public static function getRelativePaths( array $filePaths ) {
 519                 global $IP;
 520                 return array_map( function ( $path ) use ( $IP ) {
 521                         return RelPath::getRelativePath( $path, $IP );
 522                 }, $filePaths );
 523         }
 524
 525         /**
 526          * Expand directories relative to $IP.
 527          *
 528          * @since 1.27
 529          * @param array $filePaths
 530          * @return array
 531          */
 532         public static function expandRelativePaths( array $filePaths ) {
 533                 global $IP;
 534                 return array_map( function ( $path ) use ( $IP ) {
 535                         return RelPath::joinPath( $IP, $path );
 536                 }, $filePaths );
 537         }
 538
 539         /**
 540          * Get the hash of the message blob.
 541          *
 542          * @since 1.27
 543          * @param ResourceLoaderContext $context
 544          * @return string|null JSON blob or null if module has no messages
 545          */
 546         protected function getMessageBlob( ResourceLoaderContext $context ) {
 547                 if ( !$this->getMessages() ) {
 548                         // Don't bother consulting MessageBlobStore
 549                         return null;
 550                 }
 551                 // Message blobs may only vary language, not by context keys
 552                 $lang = $context->getLanguage();
 553                 if ( !isset( $this->msgBlobs[$lang] ) ) {
 554                         $this->getLogger()->warning( 'Message blob for {module} should have been preloaded', [
 555                                 'module' => $this->getName(),
 556                         ] );
 557                         $store = $context->getResourceLoader()->getMessageBlobStore();
 558                         $this->msgBlobs[$lang] = $store->getBlob( $this, $lang );
 559                 }
 560                 return $this->msgBlobs[$lang];
 561         }
 562
 563         /**
 564          * Set in-object cache for message blobs.
 565          *
 566          * Used to allow fetching of message blobs in batches. See ResourceLoader::preloadModuleInfo().
 567          *
 568          * @since 1.27
 569          * @param string|null $blob JSON blob or null
 570          * @param string $lang Language code
 571          */
 572         public function setMessageBlob( $blob, $lang ) {
 573                 $this->msgBlobs[$lang] = $blob;
 574         }
 575
 576         /**
 577          * Get headers to send as part of a module web response.
 578          *
 579          * It is not supported to send headers through this method that are
 580          * required to be unique or otherwise sent once in an HTTP response
 581          * because clients may make batch requests for multiple modules (as
 582          * is the default behaviour for ResourceLoader clients).
 583          *
 584          * For exclusive or aggregated headers, see ResourceLoader::sendResponseHeaders().
 585          *
 586          * @since 1.30
 587          * @param ResourceLoaderContext $context
 588          * @return string[] Array of HTTP response headers
 589          */
 590         final public function getHeaders( ResourceLoaderContext $context ) {
 591                 $headers = [];
 592
 593                 $formattedLinks = [];
 594                 foreach ( $this->getPreloadLinks( $context ) as $url => $attribs ) {
 595                         $link = "<{$url}>;rel=preload";
 596                         foreach ( $attribs as $key => $val ) {
 597                                 $link .= ";{$key}={$val}";
 598                         }
 599                         $formattedLinks[] = $link;
 600                 }
 601                 if ( $formattedLinks ) {
 602                         $headers[] = 'Link: ' . implode( ',', $formattedLinks );
 603                 }
 604
 605                 return $headers;
 606         }
 607
 608         /**
 609          * Get a list of resources that web browsers may preload.
 610          *
 611          * Behaviour of rel=preload link is specified at <https://www.w3.org/TR/preload/>.
 612          *
 613          * Use case for ResourceLoader originally part of T164299.
 614          *
 615          * @par Example
 616          * @code
 617          *     protected function getPreloadLinks() {
 618          *         return [
 619          *             'https://example.org/script.js' => [ 'as' => 'script' ],
 620          *             'https://example.org/image.png' => [ 'as' => 'image' ],
 621          *         ];
 622          *     }
 623          * @endcode
 624          *
 625          * @par Example using HiDPI image variants
 626          * @code
 627          *     protected function getPreloadLinks() {
 628          *         return [
 629          *             'https://example.org/logo.png' => [
 630          *                 'as' => 'image',
 631          *                 'media' => 'not all and (min-resolution: 2dppx)',
 632          *             ],
 633          *             'https://example.org/logo@2x.png' => [
 634          *                 'as' => 'image',
 635          *                 'media' => '(min-resolution: 2dppx)',
 636          *             ],
 637          *         ];
 638          *     }
 639          * @endcode
 640          *
 641          * @see ResourceLoaderModule::getHeaders
 642          * @since 1.30
 643          * @param ResourceLoaderContext $context
 644          * @return array Keyed by url, values must be an array containing
 645          *  at least an 'as' key. Optionally a 'media' key as well.
 646          */
 647         protected function getPreloadLinks( ResourceLoaderContext $context ) {
 648                 return [];
 649         }
 650
 651         /**
 652          * Get module-specific LESS variables, if any.
 653          *
 654          * @since 1.27
 655          * @param ResourceLoaderContext $context
 656          * @return array Module-specific LESS variables.
 657          */
 658         protected function getLessVars( ResourceLoaderContext $context ) {
 659                 return [];
 660         }
 661
 662         /**
 663          * Get an array of this module's resources. Ready for serving to the web.
 664          *
 665          * @since 1.26
 666          * @param ResourceLoaderContext $context
 667          * @return array
 668          */
 669         public function getModuleContent( ResourceLoaderContext $context ) {
 670                 $contextHash = $context->getHash();
 671                 // Cache this expensive operation. This calls builds the scripts, styles, and messages
 672                 // content which typically involves filesystem and/or database access.
 673                 if ( !array_key_exists( $contextHash, $this->contents ) ) {
 674                         $this->contents[$contextHash] = $this->buildContent( $context );
 675                 }
 676                 return $this->contents[$contextHash];
 677         }
 678
 679         /**
 680          * Bundle all resources attached to this module into an array.
 681          *
 682          * @since 1.26
 683          * @param ResourceLoaderContext $context
 684          * @return array
 685          */
 686         final protected function buildContent( ResourceLoaderContext $context ) {
 687                 $rl = $context->getResourceLoader();
 688                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 689                 $statStart = microtime( true );
 690
 691                 // Only include properties that are relevant to this context (e.g. only=scripts)
 692                 // and that are non-empty (e.g. don't include "templates" for modules without
 693                 // templates). This helps prevent invalidating cache for all modules when new
 694                 // optional properties are introduced.
 695                 $content = [];
 696
 697                 // Scripts
 698                 if ( $context->shouldIncludeScripts() ) {
 699                         // If we are in debug mode, we'll want to return an array of URLs if possible
 700                         // However, we can't do this if the module doesn't support it
 701                         // We also can't do this if there is an only= parameter, because we have to give
 702                         // the module a way to return a load.php URL without causing an infinite loop
 703                         if ( $context->getDebug() && !$context->getOnly() && $this->supportsURLLoading() ) {
 704                                 $scripts = $this->getScriptURLsForDebug( $context );
 705                         } else {
 706                                 $scripts = $this->getScript( $context );
 707                                 // Make the script safe to concatenate by making sure there is at least one
 708                                 // trailing new line at the end of the content. Previously, this looked for
 709                                 // a semi-colon instead, but that breaks concatenation if the semicolon
 710                                 // is inside a comment like "// foo();". Instead, simply use a
 711                                 // line break as separator which matches JavaScript native logic for implicitly
 712                                 // ending statements even if a semi-colon is missing.
 713                                 // Bugs: T29054, T162719.
 714                                 if ( is_string( $scripts )
 715                                         && strlen( $scripts )
 716                                         && substr( $scripts, -1 ) !== "\n"
 717                                 ) {
 718                                         $scripts .= "\n";
 719                                 }
 720                         }
 721                         $content['scripts'] = $scripts;
 722                 }
 723
 724                 // Styles
 725                 if ( $context->shouldIncludeStyles() ) {
 726                         $styles = [];
 727                         // Don't create empty stylesheets like [ '' => '' ] for modules
 728                         // that don't *have* any stylesheets (T40024).
 729                         $stylePairs = $this->getStyles( $context );
 730                         if ( count( $stylePairs ) ) {
 731                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 732                                 // See comment near shouldIncludeScripts() for more details
 733                                 if ( $context->getDebug() && !$context->getOnly() && $this->supportsURLLoading() ) {
 734                                         $styles = [
 735                                                 'url' => $this->getStyleURLsForDebug( $context )
 736                                         ];
 737                                 } else {
 738                                         // Minify CSS before embedding in mw.loader.implement call
 739                                         // (unless in debug mode)
 740                                         if ( !$context->getDebug() ) {
 741                                                 foreach ( $stylePairs as $media => $style ) {
 742                                                         // Can be either a string or an array of strings.
 743                                                         if ( is_array( $style ) ) {
 744                                                                 $stylePairs[$media] = [];
 745                                                                 foreach ( $style as $cssText ) {
 746                                                                         if ( is_string( $cssText ) ) {
 747                                                                                 $stylePairs[$media][] =
 748                                                                                         ResourceLoader::filter( 'minify-css', $cssText );
 749                                                                         }
 750                                                                 }
 751                                                         } elseif ( is_string( $style ) ) {
 752                                                                 $stylePairs[$media] = ResourceLoader::filter( 'minify-css', $style );
 753                                                         }
 754                                                 }
 755                                         }
 756                                         // Wrap styles into @media groups as needed and flatten into a numerical array
 757                                         $styles = [
 758                                                 'css' => $rl->makeCombinedStyles( $stylePairs )
 759                                         ];
 760                                 }
 761                         }
 762                         $content['styles'] = $styles;
 763                 }
 764
 765                 // Messages
 766                 $blob = $this->getMessageBlob( $context );
 767                 if ( $blob ) {
 768                         $content['messagesBlob'] = $blob;
 769                 }
 770
 771                 $templates = $this->getTemplates();
 772                 if ( $templates ) {
 773                         $content['templates'] = $templates;
 774                 }
 775
 776                 $headers = $this->getHeaders( $context );
 777                 if ( $headers ) {
 778                         $content['headers'] = $headers;
 779                 }
 780
 781                 $statTiming = microtime( true ) - $statStart;
 782                 $statName = strtr( $this->getName(), '.', '_' );
 783                 $stats->timing( "resourceloader_build.all", 1000 * $statTiming );
 784                 $stats->timing( "resourceloader_build.$statName", 1000 * $statTiming );
 785
 786                 return $content;
 787         }
 788
 789         /**
 790          * Get a string identifying the current version of this module in a given context.
 791          *
 792          * Whenever anything happens that changes the module's response (e.g. scripts, styles, and
 793          * messages) this value must change. This value is used to store module responses in cache.
 794          * (Both client-side and server-side.)
 795          *
 796          * It is not recommended to override this directly. Use getDefinitionSummary() instead.
 797          * If overridden, one must call the parent getVersionHash(), append data and re-hash.
 798          *
 799          * This method should be quick because it is frequently run by ResourceLoaderStartUpModule to
 800          * propagate changes to the client and effectively invalidate cache.
 801          *
 802          * For backward-compatibility, the following optional data providers are automatically included:
 803          *
 804          * - getModifiedTime()
 805          * - getModifiedHash()
 806          *
 807          * @since 1.26
 808          * @param ResourceLoaderContext $context
 809          * @return string Hash (should use ResourceLoader::makeHash)
 810          */
 811         public function getVersionHash( ResourceLoaderContext $context ) {
 812                 // The startup module produces a manifest with versions representing the entire module.
 813                 // Typically, the request for the startup module itself has only=scripts. That must apply
 814                 // only to the startup module content, and not to the module version computed here.
 815                 $context = new DerivativeResourceLoaderContext( $context );
 816                 $context->setModules( [] );
 817                 // Version hash must cover all resources, regardless of startup request itself.
 818                 $context->setOnly( null );
 819                 // Compute version hash based on content, not debug urls.
 820                 $context->setDebug( false );
 821
 822                 // Cache this somewhat expensive operation. Especially because some classes
 823                 // (e.g. startup module) iterate more than once over all modules to get versions.
 824                 $contextHash = $context->getHash();
 825                 if ( !array_key_exists( $contextHash, $this->versionHash ) ) {
 826                         if ( $this->enableModuleContentVersion() ) {
 827                                 // Detect changes directly
 828                                 $str = json_encode( $this->getModuleContent( $context ) );
 829                         } else {
 830                                 // Infer changes based on definition and other metrics
 831                                 $summary = $this->getDefinitionSummary( $context );
 832                                 if ( !isset( $summary['_cacheEpoch'] ) ) {
 833                                         throw new LogicException( 'getDefinitionSummary must call parent method' );
 834                                 }
 835                                 $str = json_encode( $summary );
 836
 837                                 $mtime = $this->getModifiedTime( $context );
 838                                 if ( $mtime !== null ) {
 839                                         // Support: MediaWiki 1.25 and earlier
 840                                         $str .= strval( $mtime );
 841                                 }
 842
 843                                 $mhash = $this->getModifiedHash( $context );
 844                                 if ( $mhash !== null ) {
 845                                         // Support: MediaWiki 1.25 and earlier
 846                                         $str .= strval( $mhash );
 847                                 }
 848                         }
 849
 850                         $this->versionHash[$contextHash] = ResourceLoader::makeHash( $str );
 851                 }
 852                 return $this->versionHash[$contextHash];
 853         }
 854
 855         /**
 856          * Whether to generate version hash based on module content.
 857          *
 858          * If a module requires database or file system access to build the module
 859          * content, consider disabling this in favour of manually tracking relevant
 860          * aspects in getDefinitionSummary(). See getVersionHash() for how this is used.
 861          *
 862          * @return bool
 863          */
 864         public function enableModuleContentVersion() {
 865                 return false;
 866         }
 867
 868         /**
 869          * Get the definition summary for this module.
 870          *
 871          * This is the method subclasses are recommended to use to track values in their
 872          * version hash. Call this in getVersionHash() and pass it to e.g. json_encode.
 873          *
 874          * Subclasses must call the parent getDefinitionSummary() and build on that.
 875          * It is recommended that each subclass appends its own new array. This prevents
 876          * clashes or accidental overwrites of existing keys and gives each subclass
 877          * its own scope for simple array keys.
 878          *
 879          * @code
 880          *     $summary = parent::getDefinitionSummary( $context );
 881          *     $summary[] = [
 882          *         'foo' => 123,
 883          *         'bar' => 'quux',
 884          *     ];
 885          *     return $summary;
 886          * @endcode
 887          *
 888          * Return an array containing values from all significant properties of this
 889          * module's definition.
 890          *
 891          * Be careful not to normalise too much. Especially preserve the order of things
 892          * that carry significance in getScript and getStyles (T39812).
 893          *
 894          * Avoid including things that are insiginificant (e.g. order of message keys is
 895          * insignificant and should be sorted to avoid unnecessary cache invalidation).
 896          *
 897          * This data structure must exclusively contain arrays and scalars as values (avoid
 898          * object instances) to allow simple serialisation using json_encode.
 899          *
 900          * If modules have a hash or timestamp from another source, that may be incuded as-is.
 901          *
 902          * A number of utility methods are available to help you gather data. These are not
 903          * called by default and must be included by the subclass' getDefinitionSummary().
 904          *
 905          * - getMessageBlob()
 906          *
 907          * @since 1.23
 908          * @param ResourceLoaderContext $context
 909          * @return array|null
 910          */
 911         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 912                 return [
 913                         '_class' => static::class,
 914                         '_cacheEpoch' => $this->getConfig()->get( 'CacheEpoch' ),
 915                 ];
 916         }
 917
 918         /**
 919          * Get this module's last modification timestamp for a given context.
 920          *
 921          * @deprecated since 1.26 Use getDefinitionSummary() instead
 922          * @param ResourceLoaderContext $context
 923          * @return int|null UNIX timestamp
 924          */
 925         public function getModifiedTime( ResourceLoaderContext $context ) {
 926                 return null;
 927         }
 928
 929         /**
 930          * Helper method for providing a version hash to getVersionHash().
 931          *
 932          * @deprecated since 1.26 Use getDefinitionSummary() instead
 933          * @param ResourceLoaderContext $context
 934          * @return string|null Hash
 935          */
 936         public function getModifiedHash( ResourceLoaderContext $context ) {
 937                 return null;
 938         }
 939
 940         /**
 941          * Check whether this module is known to be empty. If a child class
 942          * has an easy and cheap way to determine that this module is
 943          * definitely going to be empty, it should override this method to
 944          * return true in that case. Callers may optimize the request for this
 945          * module away if this function returns true.
 946          * @param ResourceLoaderContext $context
 947          * @return bool
 948          */
 949         public function isKnownEmpty( ResourceLoaderContext $context ) {
 950                 return false;
 951         }
 952
 953         /**
 954          * Check whether this module should be embeded rather than linked
 955          *
 956          * Modules returning true here will be embedded rather than loaded by
 957          * ResourceLoaderClientHtml.
 958          *
 959          * @since 1.30
 960          * @param ResourceLoaderContext $context
 961          * @return bool
 962          */
 963         public function shouldEmbedModule( ResourceLoaderContext $context ) {
 964                 return $this->getGroup() === 'private';
 965         }
 966
 967         /** @var JSParser Lazy-initialized; use self::javaScriptParser() */
 968         private static $jsParser;
 969         private static $parseCacheVersion = 1;
 970
 971         /**
 972          * Validate a given script file; if valid returns the original source.
 973          * If invalid, returns replacement JS source that throws an exception.
 974          *
 975          * @param string $fileName
 976          * @param string $contents
 977          * @return string JS with the original, or a replacement error
 978          */
 979         protected function validateScriptFile( $fileName, $contents ) {
 980                 if ( !$this->getConfig()->get( 'ResourceLoaderValidateJS' ) ) {
 981                         return $contents;
 982                 }
 983                 $cache = ObjectCache::getMainWANInstance();
 984                 return $cache->getWithSetCallback(
 985                         $cache->makeGlobalKey(
 986                                 'resourceloader',
 987                                 'jsparse',
 988                                 self::$parseCacheVersion,
 989                                 md5( $contents ),
 990                                 $fileName
 991                         ),
 992                         $cache::TTL_WEEK,
 993                         function () use ( $contents, $fileName ) {
 994                                 $parser = self::javaScriptParser();
 995                                 try {
 996                                         $parser->parse( $contents, $fileName, 1 );
 997                                         $result = $contents;
 998                                 } catch ( Exception $e ) {
 999                                         // We'll save this to cache to avoid having to re-validate broken JS
1000                                         $err = $e->getMessage();
1001                                         $result = "mw.log.error(" .
1002                                                 Xml::encodeJsVar( "JavaScript parse error: $err" ) . ");";
1003                                 }
1004                                 return $result;
1005                         }
1006                 );
1007         }
1008
1009         /**
1010          * @return JSParser
1011          */
1012         protected static function javaScriptParser() {
1013                 if ( !self::$jsParser ) {
1014                         self::$jsParser = new JSParser();
1015                 }
1016                 return self::$jsParser;
1017         }
1018
1019         /**
1020          * Safe version of filemtime(), which doesn't throw a PHP warning if the file doesn't exist.
1021          * Defaults to 1.
1022          *
1023          * @param string $filePath File path
1024          * @return int UNIX timestamp
1025          */
1026         protected static function safeFilemtime( $filePath ) {
1027                 Wikimedia\suppressWarnings();
1028                 $mtime = filemtime( $filePath ) ?: 1;
1029                 Wikimedia\restoreWarnings();
1030                 return $mtime;
1031         }
1032
1033         /**
1034          * Compute a non-cryptographic string hash of a file's contents.
1035          * If the file does not exist or cannot be read, returns an empty string.
1036          *
1037          * @since 1.26 Uses MD4 instead of SHA1.
1038          * @param string $filePath File path
1039          * @return string Hash
1040          */
1041         protected static function safeFileHash( $filePath ) {
1042                 return FileContentsHasher::getFileContentsHash( $filePath );
1043         }
1044 }