includes/resourceloader/ResourceLoaderModule.php

   1 <?php
   2 /**
   3  * Abstraction for resource loader 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 /**
  26  * Abstraction for resource loader modules, with name registration and maxage functionality.
  27  */
  28 abstract class ResourceLoaderModule {
  29         # Type of resource
  30         const TYPE_SCRIPTS = 'scripts';
  31         const TYPE_STYLES = 'styles';
  32         const TYPE_COMBINED = 'combined';
  33
  34         # sitewide core module like a skin file or jQuery component
  35         const ORIGIN_CORE_SITEWIDE = 1;
  36
  37         # per-user module generated by the software
  38         const ORIGIN_CORE_INDIVIDUAL = 2;
  39
  40         # sitewide module generated from user-editable files, like MediaWiki:Common.js, or
  41         # modules accessible to multiple users, such as those generated by the Gadgets extension.
  42         const ORIGIN_USER_SITEWIDE = 3;
  43
  44         # per-user module generated from user-editable files, like User:Me/vector.js
  45         const ORIGIN_USER_INDIVIDUAL = 4;
  46
  47         # an access constant; make sure this is kept as the largest number in this group
  48         const ORIGIN_ALL = 10;
  49
  50         # script and style modules form a hierarchy of trustworthiness, with core modules like
  51         # skins and jQuery as most trustworthy, and user scripts as least trustworthy.  We can
  52         # limit the types of scripts and styles we allow to load on, say, sensitive special
  53         # pages like Special:UserLogin and Special:Preferences
  54         protected $origin = self::ORIGIN_CORE_SITEWIDE;
  55
  56         /* Protected Members */
  57
  58         protected $name = null;
  59         protected $targets = array( 'desktop' );
  60
  61         // In-object cache for file dependencies
  62         protected $fileDeps = array();
  63         // In-object cache for message blob mtime
  64         protected $msgBlobMtime = array();
  65
  66         /**
  67          * @var Config
  68          */
  69         protected $config;
  70
  71         /* Methods */
  72
  73         /**
  74          * Get this module's name. This is set when the module is registered
  75          * with ResourceLoader::register()
  76          *
  77          * @return string|null Name (string) or null if no name was set
  78          */
  79         public function getName() {
  80                 return $this->name;
  81         }
  82
  83         /**
  84          * Set this module's name. This is called by ResourceLoader::register()
  85          * when registering the module. Other code should not call this.
  86          *
  87          * @param string $name Name
  88          */
  89         public function setName( $name ) {
  90                 $this->name = $name;
  91         }
  92
  93         /**
  94          * Get this module's origin. This is set when the module is registered
  95          * with ResourceLoader::register()
  96          *
  97          * @return int ResourceLoaderModule class constant, the subclass default
  98          *     if not set manually
  99          */
 100         public function getOrigin() {
 101                 return $this->origin;
 102         }
 103
 104         /**
 105          * Set this module's origin. This is called by ResourceLoader::register()
 106          * when registering the module. Other code should not call this.
 107          *
 108          * @param int $origin Origin
 109          */
 110         public function setOrigin( $origin ) {
 111                 $this->origin = $origin;
 112         }
 113
 114         /**
 115          * @param ResourceLoaderContext $context
 116          * @return bool
 117          */
 118         public function getFlip( $context ) {
 119                 global $wgContLang;
 120
 121                 return $wgContLang->getDir() !== $context->getDirection();
 122         }
 123
 124         /**
 125          * Get all JS for this module for a given language and skin.
 126          * Includes all relevant JS except loader scripts.
 127          *
 128          * @param ResourceLoaderContext $context
 129          * @return string JavaScript code
 130          */
 131         public function getScript( ResourceLoaderContext $context ) {
 132                 // Stub, override expected
 133                 return '';
 134         }
 135
 136         /**
 137          * Takes named templates by the module and returns an array mapping.
 138          *
 139          * @return array of templates mapping template alias to content
 140          */
 141         public function getTemplates() {
 142                 // Stub, override expected.
 143                 return array();
 144         }
 145
 146         /**
 147          * @return Config
 148          * @since 1.24
 149          */
 150         public function getConfig() {
 151                 if ( $this->config === null ) {
 152                         // Ugh, fall back to default
 153                         $this->config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 154                 }
 155
 156                 return $this->config;
 157         }
 158
 159         /**
 160          * @param Config $config
 161          * @since 1.24
 162          */
 163         public function setConfig( Config $config ) {
 164                 $this->config = $config;
 165         }
 166
 167         /**
 168          * Get the URL or URLs to load for this module's JS in debug mode.
 169          * The default behavior is to return a load.php?only=scripts URL for
 170          * the module, but file-based modules will want to override this to
 171          * load the files directly.
 172          *
 173          * This function is called only when 1) we're in debug mode, 2) there
 174          * is no only= parameter and 3) supportsURLLoading() returns true.
 175          * #2 is important to prevent an infinite loop, therefore this function
 176          * MUST return either an only= URL or a non-load.php URL.
 177          *
 178          * @param ResourceLoaderContext $context
 179          * @return array Array of URLs
 180          */
 181         public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
 182                 $resourceLoader = $context->getResourceLoader();
 183                 $derivative = new DerivativeResourceLoaderContext( $context );
 184                 $derivative->setModules( array( $this->getName() ) );
 185                 $derivative->setOnly( 'scripts' );
 186                 $derivative->setDebug( true );
 187
 188                 $url = $resourceLoader->createLoaderURL(
 189                         $this->getSource(),
 190                         $derivative
 191                 );
 192
 193                 return array( $url );
 194         }
 195
 196         /**
 197          * Whether this module supports URL loading. If this function returns false,
 198          * getScript() will be used even in cases (debug mode, no only param) where
 199          * getScriptURLsForDebug() would normally be used instead.
 200          * @return bool
 201          */
 202         public function supportsURLLoading() {
 203                 return true;
 204         }
 205
 206         /**
 207          * Get all CSS for this module for a given skin.
 208          *
 209          * @param ResourceLoaderContext $context
 210          * @return array List of CSS strings or array of CSS strings keyed by media type.
 211          *  like array( 'screen' => '.foo { width: 0 }' );
 212          *  or array( 'screen' => array( '.foo { width: 0 }' ) );
 213          */
 214         public function getStyles( ResourceLoaderContext $context ) {
 215                 // Stub, override expected
 216                 return array();
 217         }
 218
 219         /**
 220          * Get the URL or URLs to load for this module's CSS in debug mode.
 221          * The default behavior is to return a load.php?only=styles URL for
 222          * the module, but file-based modules will want to override this to
 223          * load the files directly. See also getScriptURLsForDebug()
 224          *
 225          * @param ResourceLoaderContext $context
 226          * @return array Array( mediaType => array( URL1, URL2, ... ), ... )
 227          */
 228         public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
 229                 $resourceLoader = $context->getResourceLoader();
 230                 $derivative = new DerivativeResourceLoaderContext( $context );
 231                 $derivative->setModules( array( $this->getName() ) );
 232                 $derivative->setOnly( 'styles' );
 233                 $derivative->setDebug( true );
 234
 235                 $url = $resourceLoader->createLoaderURL(
 236                         $this->getSource(),
 237                         $derivative
 238                 );
 239
 240                 return array( 'all' => array( $url ) );
 241         }
 242
 243         /**
 244          * Get the messages needed for this module.
 245          *
 246          * To get a JSON blob with messages, use MessageBlobStore::get()
 247          *
 248          * @return array List of message keys. Keys may occur more than once
 249          */
 250         public function getMessages() {
 251                 // Stub, override expected
 252                 return array();
 253         }
 254
 255         /**
 256          * Get the group this module is in.
 257          *
 258          * @return string Group name
 259          */
 260         public function getGroup() {
 261                 // Stub, override expected
 262                 return null;
 263         }
 264
 265         /**
 266          * Get the origin of this module. Should only be overridden for foreign modules.
 267          *
 268          * @return string Origin name, 'local' for local modules
 269          */
 270         public function getSource() {
 271                 // Stub, override expected
 272                 return 'local';
 273         }
 274
 275         /**
 276          * Where on the HTML page should this module's JS be loaded?
 277          *  - 'top': in the "<head>"
 278          *  - 'bottom': at the bottom of the "<body>"
 279          *
 280          * @return string
 281          */
 282         public function getPosition() {
 283                 return 'bottom';
 284         }
 285
 286         /**
 287          * Whether this module's JS expects to work without the client-side ResourceLoader module.
 288          * Returning true from this function will prevent mw.loader.state() call from being
 289          * appended to the bottom of the script.
 290          *
 291          * @return bool
 292          */
 293         public function isRaw() {
 294                 return false;
 295         }
 296
 297         /**
 298          * Get the loader JS for this module, if set.
 299          *
 300          * @return mixed JavaScript loader code as a string or boolean false if no custom loader set
 301          */
 302         public function getLoaderScript() {
 303                 // Stub, override expected
 304                 return false;
 305         }
 306
 307         /**
 308          * Get a list of modules this module depends on.
 309          *
 310          * Dependency information is taken into account when loading a module
 311          * on the client side.
 312          *
 313          * To add dependencies dynamically on the client side, use a custom
 314          * loader script, see getLoaderScript()
 315          * @return array List of module names as strings
 316          */
 317         public function getDependencies() {
 318                 // Stub, override expected
 319                 return array();
 320         }
 321
 322         /**
 323          * Get target(s) for the module, eg ['desktop'] or ['desktop', 'mobile']
 324          *
 325          * @return array Array of strings
 326          */
 327         public function getTargets() {
 328                 return $this->targets;
 329         }
 330
 331         /**
 332          * Get the skip function.
 333          *
 334          * Modules that provide fallback functionality can provide a "skip function". This
 335          * function, if provided, will be passed along to the module registry on the client.
 336          * When this module is loaded (either directly or as a dependency of another module),
 337          * then this function is executed first. If the function returns true, the module will
 338          * instantly be considered "ready" without requesting the associated module resources.
 339          *
 340          * The value returned here must be valid javascript for execution in a private function.
 341          * It must not contain the "function () {" and "}" wrapper though.
 342          *
 343          * @return string|null A JavaScript function body returning a boolean value, or null
 344          */
 345         public function getSkipFunction() {
 346                 return null;
 347         }
 348
 349         /**
 350          * Get the files this module depends on indirectly for a given skin.
 351          * Currently these are only image files referenced by the module's CSS.
 352          *
 353          * @param string $skin Skin name
 354          * @return array List of files
 355          */
 356         public function getFileDependencies( $skin ) {
 357                 // Try in-object cache first
 358                 if ( isset( $this->fileDeps[$skin] ) ) {
 359                         return $this->fileDeps[$skin];
 360                 }
 361
 362                 $dbr = wfGetDB( DB_SLAVE );
 363                 $deps = $dbr->selectField( 'module_deps', 'md_deps', array(
 364                                 'md_module' => $this->getName(),
 365                                 'md_skin' => $skin,
 366                         ), __METHOD__
 367                 );
 368                 if ( !is_null( $deps ) ) {
 369                         $this->fileDeps[$skin] = (array)FormatJson::decode( $deps, true );
 370                 } else {
 371                         $this->fileDeps[$skin] = array();
 372                 }
 373                 return $this->fileDeps[$skin];
 374         }
 375
 376         /**
 377          * Set preloaded file dependency information. Used so we can load this
 378          * information for all modules at once.
 379          * @param string $skin Skin name
 380          * @param array $deps Array of file names
 381          */
 382         public function setFileDependencies( $skin, $deps ) {
 383                 $this->fileDeps[$skin] = $deps;
 384         }
 385
 386         /**
 387          * Get the last modification timestamp of the message blob for this
 388          * module in a given language.
 389          * @param string $lang Language code
 390          * @return int UNIX timestamp
 391          */
 392         public function getMsgBlobMtime( $lang ) {
 393                 if ( !isset( $this->msgBlobMtime[$lang] ) ) {
 394                         if ( !count( $this->getMessages() ) ) {
 395                                 return 1;
 396                         }
 397
 398                         $dbr = wfGetDB( DB_SLAVE );
 399                         $msgBlobMtime = $dbr->selectField( 'msg_resource', 'mr_timestamp', array(
 400                                         'mr_resource' => $this->getName(),
 401                                         'mr_lang' => $lang
 402                                 ), __METHOD__
 403                         );
 404                         // If no blob was found, but the module does have messages, that means we need
 405                         // to regenerate it. Return NOW
 406                         if ( $msgBlobMtime === false ) {
 407                                 $msgBlobMtime = wfTimestampNow();
 408                         }
 409                         $this->msgBlobMtime[$lang] = wfTimestamp( TS_UNIX, $msgBlobMtime );
 410                 }
 411                 return $this->msgBlobMtime[$lang];
 412         }
 413
 414         /**
 415          * Set a preloaded message blob last modification timestamp. Used so we
 416          * can load this information for all modules at once.
 417          * @param string $lang Language code
 418          * @param int $mtime UNIX timestamp
 419          */
 420         public function setMsgBlobMtime( $lang, $mtime ) {
 421                 $this->msgBlobMtime[$lang] = $mtime;
 422         }
 423
 424         /* Abstract Methods */
 425
 426         /**
 427          * Get this module's last modification timestamp for a given
 428          * combination of language, skin and debug mode flag. This is typically
 429          * the highest of each of the relevant components' modification
 430          * timestamps. Whenever anything happens that changes the module's
 431          * contents for these parameters, the mtime should increase.
 432          *
 433          * NOTE: The mtime of the module's messages is NOT automatically included.
 434          * If you want this to happen, you'll need to call getMsgBlobMtime()
 435          * yourself and take its result into consideration.
 436          *
 437          * NOTE: The mtime of the module's hash is NOT automatically included.
 438          * If your module provides a getModifiedHash() method, you'll need to call getHashMtime()
 439          * yourself and take its result into consideration.
 440          *
 441          * @param ResourceLoaderContext $context Context object
 442          * @return int UNIX timestamp
 443          */
 444         public function getModifiedTime( ResourceLoaderContext $context ) {
 445                 return 1;
 446         }
 447
 448         /**
 449          * Helper method for calculating when the module's hash (if it has one) changed.
 450          *
 451          * @param ResourceLoaderContext $context
 452          * @return int UNIX timestamp
 453          */
 454         public function getHashMtime( ResourceLoaderContext $context ) {
 455                 $hash = $this->getModifiedHash( $context );
 456                 if ( !is_string( $hash ) ) {
 457                         return 1;
 458                 }
 459
 460                 // Embed the hash itself in the cache key. This allows for a few nifty things:
 461                 // - During deployment, servers with old and new versions of the code communicating
 462                 //   with the same memcached will not override the same key repeatedly increasing
 463                 //   the timestamp.
 464                 // - In case of the definition changing and then changing back in a short period of time
 465                 //   (e.g. in case of a revert or a corrupt server) the old timestamp and client-side cache
 466                 //   url will be re-used.
 467                 // - If different context-combinations (e.g. same skin, same language or some combination
 468                 //   thereof) result in the same definition, they will use the same hash and timestamp.
 469                 $cache = wfGetCache( CACHE_ANYTHING );
 470                 $key = wfMemcKey( 'resourceloader', 'hashmtime', $this->getName(), $hash );
 471
 472                 $data = $cache->get( $key );
 473                 if ( is_int( $data ) && $data > 0 ) {
 474                         // We've seen this hash before, re-use the timestamp of when we first saw it.
 475                         return $data;
 476                 }
 477
 478                 $timestamp = time();
 479                 $cache->set( $key, $timestamp );
 480                 return $timestamp;
 481         }
 482
 483         /**
 484          * Get the hash for whatever this module may contain.
 485          *
 486          * This is the method subclasses should implement if they want to make
 487          * use of getHashMTime() inside getModifiedTime().
 488          *
 489          * @param ResourceLoaderContext $context
 490          * @return string|null Hash
 491          */
 492         public function getModifiedHash( ResourceLoaderContext $context ) {
 493                 return null;
 494         }
 495
 496         /**
 497          * Helper method for calculating when this module's definition summary was last changed.
 498          *
 499          * @since 1.23
 500          *
 501          * @param ResourceLoaderContext $context
 502          * @return int UNIX timestamp
 503          */
 504         public function getDefinitionMtime( ResourceLoaderContext $context ) {
 505                 $summary = $this->getDefinitionSummary( $context );
 506                 if ( $summary === null ) {
 507                         return 1;
 508                 }
 509
 510                 $hash = md5( json_encode( $summary ) );
 511                 $cache = wfGetCache( CACHE_ANYTHING );
 512                 $key = wfMemcKey( 'resourceloader', 'moduledefinition', $this->getName(), $hash );
 513
 514                 $data = $cache->get( $key );
 515                 if ( is_int( $data ) && $data > 0 ) {
 516                         // We've seen this hash before, re-use the timestamp of when we first saw it.
 517                         return $data;
 518                 }
 519
 520                 wfDebugLog( 'resourceloader', __METHOD__ . ": New definition for module "
 521                         . "{$this->getName()} in context \"{$context->getHash()}\"" );
 522                 // WMF logging for T94810
 523                 global $wgRequest;
 524                 if ( isset( $wgRequest ) && $context->getUser() ) {
 525                         wfDebugLog( 'resourceloader', __METHOD__ . ": Request with user parameter in "
 526                         . "context \"{$context->getHash()}\" from " . $wgRequest->getRequestURL() );
 527                 }
 528
 529                 $timestamp = time();
 530                 $cache->set( $key, $timestamp );
 531                 return $timestamp;
 532         }
 533
 534         /**
 535          * Get the definition summary for this module.
 536          *
 537          * This is the method subclasses should implement if they want to make
 538          * use of getDefinitionMTime() inside getModifiedTime().
 539          *
 540          * Return an array containing values from all significant properties of this
 541          * module's definition. Be sure to include things that are explicitly ordered,
 542          * in their actaul order (bug 37812).
 543          *
 544          * Avoid including things that are insiginificant (e.g. order of message
 545          * keys is insignificant and should be sorted to avoid unnecessary cache
 546          * invalidation).
 547          *
 548          * Avoid including things already considered by other methods inside your
 549          * getModifiedTime(), such as file mtime timestamps.
 550          *
 551          * Serialisation is done using json_encode, which means object state is not
 552          * taken into account when building the hash. This data structure must only
 553          * contain arrays and scalars as values (avoid object instances) which means
 554          * it requires abstraction.
 555          *
 556          * @since 1.23
 557          *
 558          * @param ResourceLoaderContext $context
 559          * @return array|null
 560          */
 561         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 562                 return array(
 563                         'class' => get_class( $this ),
 564                 );
 565         }
 566
 567         /**
 568          * Check whether this module is known to be empty. If a child class
 569          * has an easy and cheap way to determine that this module is
 570          * definitely going to be empty, it should override this method to
 571          * return true in that case. Callers may optimize the request for this
 572          * module away if this function returns true.
 573          * @param ResourceLoaderContext $context
 574          * @return bool
 575          */
 576         public function isKnownEmpty( ResourceLoaderContext $context ) {
 577                 return false;
 578         }
 579
 580         /** @var JSParser Lazy-initialized; use self::javaScriptParser() */
 581         private static $jsParser;
 582         private static $parseCacheVersion = 1;
 583
 584         /**
 585          * Validate a given script file; if valid returns the original source.
 586          * If invalid, returns replacement JS source that throws an exception.
 587          *
 588          * @param string $fileName
 589          * @param string $contents
 590          * @return string JS with the original, or a replacement error
 591          */
 592         protected function validateScriptFile( $fileName, $contents ) {
 593                 if ( $this->getConfig()->get( 'ResourceLoaderValidateJS' ) ) {
 594                         // Try for cache hit
 595                         // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 596                         $key = wfMemcKey( 'resourceloader', 'jsparse', self::$parseCacheVersion, md5( $contents ) );
 597                         $cache = wfGetCache( CACHE_ANYTHING );
 598                         $cacheEntry = $cache->get( $key );
 599                         if ( is_string( $cacheEntry ) ) {
 600                                 return $cacheEntry;
 601                         }
 602
 603                         $parser = self::javaScriptParser();
 604                         try {
 605                                 $parser->parse( $contents, $fileName, 1 );
 606                                 $result = $contents;
 607                         } catch ( Exception $e ) {
 608                                 // We'll save this to cache to avoid having to validate broken JS over and over...
 609                                 $err = $e->getMessage();
 610                                 $result = "throw new Error(" . Xml::encodeJsVar( "JavaScript parse error: $err" ) . ");";
 611                         }
 612
 613                         $cache->set( $key, $result );
 614                         return $result;
 615                 } else {
 616                         return $contents;
 617                 }
 618         }
 619
 620         /**
 621          * @return JSParser
 622          */
 623         protected static function javaScriptParser() {
 624                 if ( !self::$jsParser ) {
 625                         self::$jsParser = new JSParser();
 626                 }
 627                 return self::$jsParser;
 628         }
 629
 630         /**
 631          * Safe version of filemtime(), which doesn't throw a PHP warning if the file doesn't exist
 632          * but returns 1 instead.
 633          * @param string $filename File name
 634          * @return int UNIX timestamp
 635          */
 636         protected static function safeFilemtime( $filename ) {
 637                 wfSuppressWarnings();
 638                 $mtime = filemtime( $filename ) ?: 1;
 639                 wfRestoreWarnings();
 640
 641                 return $mtime;
 642         }
 643 }