includes/resourceloader/ResourceLoaderFileModule.php

   1 <?php
   2 /**
   3  * Resource loader module based on local JavaScript/CSS files.
   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  * ResourceLoader module based on local JavaScript/CSS files.
  27  */
  28 class ResourceLoaderFileModule extends ResourceLoaderModule {
  29         /* Protected Members */
  30
  31         /** @var string Local base path, see __construct() */
  32         protected $localBasePath = '';
  33
  34         /** @var string Remote base path, see __construct() */
  35         protected $remoteBasePath = '';
  36
  37         /** @var array Saves a list of the templates named by the modules. */
  38         protected $templates = array();
  39
  40         /**
  41          * @var array List of paths to JavaScript files to always include
  42          * @par Usage:
  43          * @code
  44          * array( [file-path], [file-path], ... )
  45          * @endcode
  46          */
  47         protected $scripts = array();
  48
  49         /**
  50          * @var array List of JavaScript files to include when using a specific language
  51          * @par Usage:
  52          * @code
  53          * array( [language-code] => array( [file-path], [file-path], ... ), ... )
  54          * @endcode
  55          */
  56         protected $languageScripts = array();
  57
  58         /**
  59          * @var array List of JavaScript files to include when using a specific skin
  60          * @par Usage:
  61          * @code
  62          * array( [skin-name] => array( [file-path], [file-path], ... ), ... )
  63          * @endcode
  64          */
  65         protected $skinScripts = array();
  66
  67         /**
  68          * @var array List of paths to JavaScript files to include in debug mode
  69          * @par Usage:
  70          * @code
  71          * array( [skin-name] => array( [file-path], [file-path], ... ), ... )
  72          * @endcode
  73          */
  74         protected $debugScripts = array();
  75
  76         /**
  77          * @var array List of paths to JavaScript files to include in the startup module
  78          * @par Usage:
  79          * @code
  80          * array( [file-path], [file-path], ... )
  81          * @endcode
  82          */
  83         protected $loaderScripts = array();
  84
  85         /**
  86          * @var array List of paths to CSS files to always include
  87          * @par Usage:
  88          * @code
  89          * array( [file-path], [file-path], ... )
  90          * @endcode
  91          */
  92         protected $styles = array();
  93
  94         /**
  95          * @var array List of paths to CSS files to include when using specific skins
  96          * @par Usage:
  97          * @code
  98          * array( [file-path], [file-path], ... )
  99          * @endcode
 100          */
 101         protected $skinStyles = array();
 102
 103         /**
 104          * @var array List of modules this module depends on
 105          * @par Usage:
 106          * @code
 107          * array( [file-path], [file-path], ... )
 108          * @endcode
 109          */
 110         protected $dependencies = array();
 111
 112         /**
 113          * @var string File name containing the body of the skip function
 114          */
 115         protected $skipFunction = null;
 116
 117         /**
 118          * @var array List of message keys used by this module
 119          * @par Usage:
 120          * @code
 121          * array( [message-key], [message-key], ... )
 122          * @endcode
 123          */
 124         protected $messages = array();
 125
 126         /** @var string Name of group to load this module in */
 127         protected $group;
 128
 129         /** @var string Position on the page to load this module at */
 130         protected $position = 'bottom';
 131
 132         /** @var bool Link to raw files in debug mode */
 133         protected $debugRaw = true;
 134
 135         /** @var bool Whether mw.loader.state() call should be omitted */
 136         protected $raw = false;
 137
 138         protected $targets = array( 'desktop' );
 139
 140         /**
 141          * @var bool Whether getStyleURLsForDebug should return raw file paths,
 142          * or return load.php urls
 143          */
 144         protected $hasGeneratedStyles = false;
 145
 146         /**
 147          * @var array Place where readStyleFile() tracks file dependencies
 148          * @par Usage:
 149          * @code
 150          * array( [file-path], [file-path], ... )
 151          * @endcode
 152          */
 153         protected $localFileRefs = array();
 154
 155         /**
 156          * @var array Place where readStyleFile() tracks file dependencies for non-existent files.
 157          * Used in tests to detect missing dependencies.
 158          */
 159         protected $missingLocalFileRefs = array();
 160
 161         /* Methods */
 162
 163         /**
 164          * Constructs a new module from an options array.
 165          *
 166          * @param array $options List of options; if not given or empty, an empty module will be
 167          *     constructed
 168          * @param string $localBasePath Base path to prepend to all local paths in $options. Defaults
 169          *     to $IP
 170          * @param string $remoteBasePath Base path to prepend to all remote paths in $options. Defaults
 171          *     to $wgResourceBasePath
 172          *
 173          * Below is a description for the $options array:
 174          * @throws InvalidArgumentException
 175          * @par Construction options:
 176          * @code
 177          *     array(
 178          *         // Base path to prepend to all local paths in $options. Defaults to $IP
 179          *         'localBasePath' => [base path],
 180          *         // Base path to prepend to all remote paths in $options. Defaults to $wgResourceBasePath
 181          *         'remoteBasePath' => [base path],
 182          *         // Equivalent of remoteBasePath, but relative to $wgExtensionAssetsPath
 183          *         'remoteExtPath' => [base path],
 184          *         // Equivalent of remoteBasePath, but relative to $wgStylePath
 185          *         'remoteSkinPath' => [base path],
 186          *         // Scripts to always include
 187          *         'scripts' => [file path string or array of file path strings],
 188          *         // Scripts to include in specific language contexts
 189          *         'languageScripts' => array(
 190          *             [language code] => [file path string or array of file path strings],
 191          *         ),
 192          *         // Scripts to include in specific skin contexts
 193          *         'skinScripts' => array(
 194          *             [skin name] => [file path string or array of file path strings],
 195          *         ),
 196          *         // Scripts to include in debug contexts
 197          *         'debugScripts' => [file path string or array of file path strings],
 198          *         // Scripts to include in the startup module
 199          *         'loaderScripts' => [file path string or array of file path strings],
 200          *         // Modules which must be loaded before this module
 201          *         'dependencies' => [module name string or array of module name strings],
 202          *         'templates' => array(
 203          *             [template alias with file.ext] => [file path to a template file],
 204          *         ),
 205          *         // Styles to always load
 206          *         'styles' => [file path string or array of file path strings],
 207          *         // Styles to include in specific skin contexts
 208          *         'skinStyles' => array(
 209          *             [skin name] => [file path string or array of file path strings],
 210          *         ),
 211          *         // Messages to always load
 212          *         'messages' => [array of message key strings],
 213          *         // Group which this module should be loaded together with
 214          *         'group' => [group name string],
 215          *         // Position on the page to load this module at
 216          *         'position' => ['bottom' (default) or 'top']
 217          *         // Function that, if it returns true, makes the loader skip this module.
 218          *         // The file must contain valid JavaScript for execution in a private function.
 219          *         // The file must not contain the "function () {" and "}" wrapper though.
 220          *         'skipFunction' => [file path]
 221          *     )
 222          * @endcode
 223          */
 224         public function __construct(
 225                 $options = array(),
 226                 $localBasePath = null,
 227                 $remoteBasePath = null
 228         ) {
 229                 // Flag to decide whether to automagically add the mediawiki.template module
 230                 $hasTemplates = false;
 231                 // localBasePath and remoteBasePath both have unbelievably long fallback chains
 232                 // and need to be handled separately.
 233                 list( $this->localBasePath, $this->remoteBasePath ) =
 234                         self::extractBasePaths( $options, $localBasePath, $remoteBasePath );
 235
 236                 // Extract, validate and normalise remaining options
 237                 foreach ( $options as $member => $option ) {
 238                         switch ( $member ) {
 239                                 // Lists of file paths
 240                                 case 'scripts':
 241                                 case 'debugScripts':
 242                                 case 'loaderScripts':
 243                                 case 'styles':
 244                                         $this->{$member} = (array)$option;
 245                                         break;
 246                                 case 'templates':
 247                                         $hasTemplates = true;
 248                                         $this->{$member} = (array)$option;
 249                                         break;
 250                                 // Collated lists of file paths
 251                                 case 'languageScripts':
 252                                 case 'skinScripts':
 253                                 case 'skinStyles':
 254                                         if ( !is_array( $option ) ) {
 255                                                 throw new InvalidArgumentException(
 256                                                         "Invalid collated file path list error. " .
 257                                                         "'$option' given, array expected."
 258                                                 );
 259                                         }
 260                                         foreach ( $option as $key => $value ) {
 261                                                 if ( !is_string( $key ) ) {
 262                                                         throw new InvalidArgumentException(
 263                                                                 "Invalid collated file path list key error. " .
 264                                                                 "'$key' given, string expected."
 265                                                         );
 266                                                 }
 267                                                 $this->{$member}[$key] = (array)$value;
 268                                         }
 269                                         break;
 270                                 // Lists of strings
 271                                 case 'dependencies':
 272                                 case 'messages':
 273                                 case 'targets':
 274                                         // Normalise
 275                                         $option = array_values( array_unique( (array)$option ) );
 276                                         sort( $option );
 277
 278                                         $this->{$member} = $option;
 279                                         break;
 280                                 // Single strings
 281                                 case 'position':
 282                                         $this->isPositionDefined = true;
 283                                 case 'group':
 284                                 case 'skipFunction':
 285                                         $this->{$member} = (string)$option;
 286                                         break;
 287                                 // Single booleans
 288                                 case 'debugRaw':
 289                                 case 'raw':
 290                                         $this->{$member} = (bool)$option;
 291                                         break;
 292                         }
 293                 }
 294                 if ( $hasTemplates ) {
 295                         $this->dependencies[] = 'mediawiki.template';
 296                         // Ensure relevant template compiler module gets loaded
 297                         foreach ( $this->templates as $alias => $templatePath ) {
 298                                 if ( is_int( $alias ) ) {
 299                                         $alias = $templatePath;
 300                                 }
 301                                 $suffix = explode( '.', $alias );
 302                                 $suffix = end( $suffix );
 303                                 $compilerModule = 'mediawiki.template.' . $suffix;
 304                                 if ( $suffix !== 'html' && !in_array( $compilerModule, $this->dependencies ) ) {
 305                                         $this->dependencies[] = $compilerModule;
 306                                 }
 307                         }
 308                 }
 309         }
 310
 311         /**
 312          * Extract a pair of local and remote base paths from module definition information.
 313          * Implementation note: the amount of global state used in this function is staggering.
 314          *
 315          * @param array $options Module definition
 316          * @param string $localBasePath Path to use if not provided in module definition. Defaults
 317          *     to $IP
 318          * @param string $remoteBasePath Path to use if not provided in module definition. Defaults
 319          *     to $wgResourceBasePath
 320          * @return array Array( localBasePath, remoteBasePath )
 321          */
 322         public static function extractBasePaths(
 323                 $options = array(),
 324                 $localBasePath = null,
 325                 $remoteBasePath = null
 326         ) {
 327                 global $IP, $wgResourceBasePath;
 328
 329                 // The different ways these checks are done, and their ordering, look very silly,
 330                 // but were preserved for backwards-compatibility just in case. Tread lightly.
 331
 332                 if ( $localBasePath === null ) {
 333                         $localBasePath = $IP;
 334                 }
 335                 if ( $remoteBasePath === null ) {
 336                         $remoteBasePath = $wgResourceBasePath;
 337                 }
 338
 339                 if ( isset( $options['remoteExtPath'] ) ) {
 340                         global $wgExtensionAssetsPath;
 341                         $remoteBasePath = $wgExtensionAssetsPath . '/' . $options['remoteExtPath'];
 342                 }
 343
 344                 if ( isset( $options['remoteSkinPath'] ) ) {
 345                         global $wgStylePath;
 346                         $remoteBasePath = $wgStylePath . '/' . $options['remoteSkinPath'];
 347                 }
 348
 349                 if ( array_key_exists( 'localBasePath', $options ) ) {
 350                         $localBasePath = (string)$options['localBasePath'];
 351                 }
 352
 353                 if ( array_key_exists( 'remoteBasePath', $options ) ) {
 354                         $remoteBasePath = (string)$options['remoteBasePath'];
 355                 }
 356
 357                 // Make sure the remote base path is a complete valid URL,
 358                 // but possibly protocol-relative to avoid cache pollution
 359                 $remoteBasePath = wfExpandUrl( $remoteBasePath, PROTO_RELATIVE );
 360
 361                 return array( $localBasePath, $remoteBasePath );
 362         }
 363
 364         /**
 365          * Gets all scripts for a given context concatenated together.
 366          *
 367          * @param ResourceLoaderContext $context Context in which to generate script
 368          * @return string JavaScript code for $context
 369          */
 370         public function getScript( ResourceLoaderContext $context ) {
 371                 $files = $this->getScriptFiles( $context );
 372                 return $this->readScriptFiles( $files );
 373         }
 374
 375         /**
 376          * @param ResourceLoaderContext $context
 377          * @return array
 378          */
 379         public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
 380                 $urls = array();
 381                 foreach ( $this->getScriptFiles( $context ) as $file ) {
 382                         $urls[] = $this->getRemotePath( $file );
 383                 }
 384                 return $urls;
 385         }
 386
 387         /**
 388          * @return bool
 389          */
 390         public function supportsURLLoading() {
 391                 return $this->debugRaw;
 392         }
 393
 394         /**
 395          * Get loader script.
 396          *
 397          * @return string|bool JavaScript code to be added to startup module
 398          */
 399         public function getLoaderScript() {
 400                 if ( count( $this->loaderScripts ) === 0 ) {
 401                         return false;
 402                 }
 403                 return $this->readScriptFiles( $this->loaderScripts );
 404         }
 405
 406         /**
 407          * Get all styles for a given context.
 408          *
 409          * @param ResourceLoaderContext $context
 410          * @return array CSS code for $context as an associative array mapping media type to CSS text.
 411          */
 412         public function getStyles( ResourceLoaderContext $context ) {
 413                 $styles = $this->readStyleFiles(
 414                         $this->getStyleFiles( $context ),
 415                         $this->getFlip( $context ),
 416                         $context
 417                 );
 418                 // Collect referenced files
 419                 $this->localFileRefs = array_unique( $this->localFileRefs );
 420                 // If the list has been modified since last time we cached it, update the cache
 421                 try {
 422                         if ( $this->localFileRefs !== $this->getFileDependencies( $context->getSkin() ) ) {
 423                                 $dbw = wfGetDB( DB_MASTER );
 424                                 $dbw->replace( 'module_deps',
 425                                         array( array( 'md_module', 'md_skin' ) ), array(
 426                                                 'md_module' => $this->getName(),
 427                                                 'md_skin' => $context->getSkin(),
 428                                                 'md_deps' => FormatJson::encode( $this->localFileRefs ),
 429                                         )
 430                                 );
 431                         }
 432                 } catch ( Exception $e ) {
 433                         wfDebugLog( 'resourceloader', __METHOD__ . ": failed to update DB: $e" );
 434                 }
 435                 return $styles;
 436         }
 437
 438         /**
 439          * @param ResourceLoaderContext $context
 440          * @return array
 441          */
 442         public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
 443                 if ( $this->hasGeneratedStyles ) {
 444                         // Do the default behaviour of returning a url back to load.php
 445                         // but with only=styles.
 446                         return parent::getStyleURLsForDebug( $context );
 447                 }
 448                 // Our module consists entirely of real css files,
 449                 // in debug mode we can load those directly.
 450                 $urls = array();
 451                 foreach ( $this->getStyleFiles( $context ) as $mediaType => $list ) {
 452                         $urls[$mediaType] = array();
 453                         foreach ( $list as $file ) {
 454                                 $urls[$mediaType][] = $this->getRemotePath( $file );
 455                         }
 456                 }
 457                 return $urls;
 458         }
 459
 460         /**
 461          * Gets list of message keys used by this module.
 462          *
 463          * @return array List of message keys
 464          */
 465         public function getMessages() {
 466                 return $this->messages;
 467         }
 468
 469         /**
 470          * Gets the name of the group this module should be loaded in.
 471          *
 472          * @return string Group name
 473          */
 474         public function getGroup() {
 475                 return $this->group;
 476         }
 477
 478         /**
 479          * @return string
 480          */
 481         public function getPosition() {
 482                 return $this->position;
 483         }
 484
 485         /**
 486          * Gets list of names of modules this module depends on.
 487          * @param ResourceLoaderContext context
 488          * @return array List of module names
 489          */
 490         public function getDependencies( ResourceLoaderContext $context = null ) {
 491                 return $this->dependencies;
 492         }
 493
 494         /**
 495          * Get the skip function.
 496          * @return null|string
 497          * @throws MWException
 498          */
 499         public function getSkipFunction() {
 500                 if ( !$this->skipFunction ) {
 501                         return null;
 502                 }
 503
 504                 $localPath = $this->getLocalPath( $this->skipFunction );
 505                 if ( !file_exists( $localPath ) ) {
 506                         throw new MWException( __METHOD__ . ": skip function file not found: \"$localPath\"" );
 507                 }
 508                 $contents = file_get_contents( $localPath );
 509                 if ( $this->getConfig()->get( 'ResourceLoaderValidateStaticJS' ) ) {
 510                         $contents = $this->validateScriptFile( $localPath, $contents );
 511                 }
 512                 return $contents;
 513         }
 514
 515         /**
 516          * @return bool
 517          */
 518         public function isRaw() {
 519                 return $this->raw;
 520         }
 521
 522         /**
 523          * Disable module content versioning.
 524          *
 525          * This class uses getDefinitionSummary() instead, to avoid filesystem overhead
 526          * involved with building the full module content inside a startup request.
 527          *
 528          * @return bool
 529          */
 530         public function enableModuleContentVersion() {
 531                 return false;
 532         }
 533
 534         /**
 535          * Helper method to gather file hashes for getDefinitionSummary.
 536          *
 537          * This function is context-sensitive, only computing hashes of files relevant to the
 538          * given language, skin, etc.
 539          *
 540          * @see ResourceLoaderModule::getFileDependencies
 541          * @param ResourceLoaderContext $context
 542          * @return array
 543          */
 544         protected function getFileHashes( ResourceLoaderContext $context ) {
 545                 $files = array();
 546
 547                 // Flatten style files into $files
 548                 $styles = self::collateFilePathListByOption( $this->styles, 'media', 'all' );
 549                 foreach ( $styles as $styleFiles ) {
 550                         $files = array_merge( $files, $styleFiles );
 551                 }
 552
 553                 $skinFiles = self::collateFilePathListByOption(
 554                         self::tryForKey( $this->skinStyles, $context->getSkin(), 'default' ),
 555                         'media',
 556                         'all'
 557                 );
 558                 foreach ( $skinFiles as $styleFiles ) {
 559                         $files = array_merge( $files, $styleFiles );
 560                 }
 561
 562                 // Final merge, this should result in a master list of dependent files
 563                 $files = array_merge(
 564                         $files,
 565                         $this->scripts,
 566                         $this->templates,
 567                         $context->getDebug() ? $this->debugScripts : array(),
 568                         $this->getLanguageScripts( $context->getLanguage() ),
 569                         self::tryForKey( $this->skinScripts, $context->getSkin(), 'default' ),
 570                         $this->loaderScripts
 571                 );
 572                 if ( $this->skipFunction ) {
 573                         $files[] = $this->skipFunction;
 574                 }
 575                 $files = array_map( array( $this, 'getLocalPath' ), $files );
 576                 // File deps need to be treated separately because they're already prefixed
 577                 $files = array_merge( $files, $this->getFileDependencies( $context->getSkin() ) );
 578                 // Filter out any duplicates from getFileDependencies() and others.
 579                 // Most commonly introduced by compileLessFile(), which always includes the
 580                 // entry point Less file we already know about.
 581                 $files = array_values( array_unique( $files ) );
 582
 583                 // Don't include keys or file paths here, only the hashes. Including that would needlessly
 584                 // cause global cache invalidation when files move or if e.g. the MediaWiki path changes.
 585                 // Any significant ordering is already detected by the definition summary.
 586                 return array_map( array( __CLASS__, 'safeFileHash' ), $files );
 587         }
 588
 589         /**
 590          * Get the definition summary for this module.
 591          *
 592          * @param ResourceLoaderContext $context
 593          * @return array
 594          */
 595         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 596                 $summary = parent::getDefinitionSummary( $context );
 597
 598                 $options = array();
 599                 foreach ( array(
 600                         // The following properties are omitted because they don't affect the module reponse:
 601                         // - localBasePath (Per T104950; Changes when absolute directory name changes. If
 602                         //    this affects 'scripts' and other file paths, getFileHashes accounts for that.)
 603                         // - remoteBasePath (Per T104950)
 604                         // - dependencies (provided via startup module)
 605                         // - targets
 606                         // - group (provided via startup module)
 607                         // - position (only used by OutputPage)
 608                         'scripts',
 609                         'debugScripts',
 610                         'loaderScripts',
 611                         'styles',
 612                         'languageScripts',
 613                         'skinScripts',
 614                         'skinStyles',
 615                         'messages',
 616                         'templates',
 617                         'skipFunction',
 618                         'debugRaw',
 619                         'raw',
 620                 ) as $member ) {
 621                         $options[$member] = $this->{$member};
 622                 };
 623
 624                 $summary[] = array(
 625                         'options' => $options,
 626                         'fileHashes' => $this->getFileHashes( $context ),
 627                         'msgBlobMtime' => $this->getMsgBlobMtime( $context->getLanguage() ),
 628                 );
 629                 return $summary;
 630         }
 631
 632         /**
 633          * @param string|ResourceLoaderFilePath $path
 634          * @return string
 635          */
 636         protected function getLocalPath( $path ) {
 637                 if ( $path instanceof ResourceLoaderFilePath ) {
 638                         return $path->getLocalPath();
 639                 }
 640
 641                 return "{$this->localBasePath}/$path";
 642         }
 643
 644         /**
 645          * @param string|ResourceLoaderFilePath $path
 646          * @return string
 647          */
 648         protected function getRemotePath( $path ) {
 649                 if ( $path instanceof ResourceLoaderFilePath ) {
 650                         return $path->getRemotePath();
 651                 }
 652
 653                 return "{$this->remoteBasePath}/$path";
 654         }
 655
 656         /**
 657          * Infer the stylesheet language from a stylesheet file path.
 658          *
 659          * @since 1.22
 660          * @param string $path
 661          * @return string The stylesheet language name
 662          */
 663         public function getStyleSheetLang( $path ) {
 664                 return preg_match( '/\.less$/i', $path ) ? 'less' : 'css';
 665         }
 666
 667         /**
 668          * Collates file paths by option (where provided).
 669          *
 670          * @param array $list List of file paths in any combination of index/path
 671          *     or path/options pairs
 672          * @param string $option Option name
 673          * @param mixed $default Default value if the option isn't set
 674          * @return array List of file paths, collated by $option
 675          */
 676         protected static function collateFilePathListByOption( array $list, $option, $default ) {
 677                 $collatedFiles = array();
 678                 foreach ( (array)$list as $key => $value ) {
 679                         if ( is_int( $key ) ) {
 680                                 // File name as the value
 681                                 if ( !isset( $collatedFiles[$default] ) ) {
 682                                         $collatedFiles[$default] = array();
 683                                 }
 684                                 $collatedFiles[$default][] = $value;
 685                         } elseif ( is_array( $value ) ) {
 686                                 // File name as the key, options array as the value
 687                                 $optionValue = isset( $value[$option] ) ? $value[$option] : $default;
 688                                 if ( !isset( $collatedFiles[$optionValue] ) ) {
 689                                         $collatedFiles[$optionValue] = array();
 690                                 }
 691                                 $collatedFiles[$optionValue][] = $key;
 692                         }
 693                 }
 694                 return $collatedFiles;
 695         }
 696
 697         /**
 698          * Get a list of element that match a key, optionally using a fallback key.
 699          *
 700          * @param array $list List of lists to select from
 701          * @param string $key Key to look for in $map
 702          * @param string $fallback Key to look for in $list if $key doesn't exist
 703          * @return array List of elements from $map which matched $key or $fallback,
 704          *  or an empty list in case of no match
 705          */
 706         protected static function tryForKey( array $list, $key, $fallback = null ) {
 707                 if ( isset( $list[$key] ) && is_array( $list[$key] ) ) {
 708                         return $list[$key];
 709                 } elseif ( is_string( $fallback )
 710                         && isset( $list[$fallback] )
 711                         && is_array( $list[$fallback] )
 712                 ) {
 713                         return $list[$fallback];
 714                 }
 715                 return array();
 716         }
 717
 718         /**
 719          * Get a list of file paths for all scripts in this module, in order of proper execution.
 720          *
 721          * @param ResourceLoaderContext $context
 722          * @return array List of file paths
 723          */
 724         protected function getScriptFiles( ResourceLoaderContext $context ) {
 725                 $files = array_merge(
 726                         $this->scripts,
 727                         $this->getLanguageScripts( $context->getLanguage() ),
 728                         self::tryForKey( $this->skinScripts, $context->getSkin(), 'default' )
 729                 );
 730                 if ( $context->getDebug() ) {
 731                         $files = array_merge( $files, $this->debugScripts );
 732                 }
 733
 734                 return array_unique( $files, SORT_REGULAR );
 735         }
 736
 737         /**
 738          * Get the set of language scripts for the given language,
 739          * possibly using a fallback language.
 740          *
 741          * @param string $lang
 742          * @return array
 743          */
 744         private function getLanguageScripts( $lang ) {
 745                 $scripts = self::tryForKey( $this->languageScripts, $lang );
 746                 if ( $scripts ) {
 747                         return $scripts;
 748                 }
 749                 $fallbacks = Language::getFallbacksFor( $lang );
 750                 foreach ( $fallbacks as $lang ) {
 751                         $scripts = self::tryForKey( $this->languageScripts, $lang );
 752                         if ( $scripts ) {
 753                                 return $scripts;
 754                         }
 755                 }
 756
 757                 return array();
 758         }
 759
 760         /**
 761          * Get a list of file paths for all styles in this module, in order of proper inclusion.
 762          *
 763          * @param ResourceLoaderContext $context
 764          * @return array List of file paths
 765          */
 766         public function getStyleFiles( ResourceLoaderContext $context ) {
 767                 return array_merge_recursive(
 768                         self::collateFilePathListByOption( $this->styles, 'media', 'all' ),
 769                         self::collateFilePathListByOption(
 770                                 self::tryForKey( $this->skinStyles, $context->getSkin(), 'default' ),
 771                                 'media',
 772                                 'all'
 773                         )
 774                 );
 775         }
 776
 777         /**
 778          * Gets a list of file paths for all skin styles in the module used by
 779          * the skin.
 780          *
 781          * @param string $skinName The name of the skin
 782          * @return array A list of file paths collated by media type
 783          */
 784         protected function getSkinStyleFiles( $skinName ) {
 785                 return self::collateFilePathListByOption(
 786                         self::tryForKey( $this->skinStyles, $skinName ),
 787                         'media',
 788                         'all'
 789                 );
 790         }
 791
 792         /**
 793          * Gets a list of file paths for all skin style files in the module,
 794          * for all available skins.
 795          *
 796          * @return array A list of file paths collated by media type
 797          */
 798         protected function getAllSkinStyleFiles() {
 799                 $styleFiles = array();
 800                 $internalSkinNames = array_keys( Skin::getSkinNames() );
 801                 $internalSkinNames[] = 'default';
 802
 803                 foreach ( $internalSkinNames as $internalSkinName ) {
 804                         $styleFiles = array_merge_recursive(
 805                                 $styleFiles,
 806                                 $this->getSkinStyleFiles( $internalSkinName )
 807                         );
 808                 }
 809
 810                 return $styleFiles;
 811         }
 812
 813         /**
 814          * Returns all style files and all skin style files used by this module.
 815          *
 816          * @return array
 817          */
 818         public function getAllStyleFiles() {
 819                 $collatedStyleFiles = array_merge_recursive(
 820                         self::collateFilePathListByOption( $this->styles, 'media', 'all' ),
 821                         $this->getAllSkinStyleFiles()
 822                 );
 823
 824                 $result = array();
 825
 826                 foreach ( $collatedStyleFiles as $media => $styleFiles ) {
 827                         foreach ( $styleFiles as $styleFile ) {
 828                                 $result[] = $this->getLocalPath( $styleFile );
 829                         }
 830                 }
 831
 832                 return $result;
 833         }
 834
 835         /**
 836          * Gets the contents of a list of JavaScript files.
 837          *
 838          * @param array $scripts List of file paths to scripts to read, remap and concetenate
 839          * @throws MWException
 840          * @return string Concatenated and remapped JavaScript data from $scripts
 841          */
 842         protected function readScriptFiles( array $scripts ) {
 843                 if ( empty( $scripts ) ) {
 844                         return '';
 845                 }
 846                 $js = '';
 847                 foreach ( array_unique( $scripts, SORT_REGULAR ) as $fileName ) {
 848                         $localPath = $this->getLocalPath( $fileName );
 849                         if ( !file_exists( $localPath ) ) {
 850                                 throw new MWException( __METHOD__ . ": script file not found: \"$localPath\"" );
 851                         }
 852                         $contents = file_get_contents( $localPath );
 853                         if ( $this->getConfig()->get( 'ResourceLoaderValidateStaticJS' ) ) {
 854                                 // Static files don't really need to be checked as often; unlike
 855                                 // on-wiki module they shouldn't change unexpectedly without
 856                                 // admin interference.
 857                                 $contents = $this->validateScriptFile( $fileName, $contents );
 858                         }
 859                         $js .= $contents . "\n";
 860                 }
 861                 return $js;
 862         }
 863
 864         /**
 865          * Gets the contents of a list of CSS files.
 866          *
 867          * @param array $styles List of media type/list of file paths pairs, to read, remap and
 868          * concetenate
 869          * @param bool $flip
 870          * @param ResourceLoaderContext $context (optional)
 871          *
 872          * @throws MWException
 873          * @return array List of concatenated and remapped CSS data from $styles,
 874          *     keyed by media type
 875          */
 876         public function readStyleFiles( array $styles, $flip, $context = null ) {
 877                 if ( empty( $styles ) ) {
 878                         return array();
 879                 }
 880                 foreach ( $styles as $media => $files ) {
 881                         $uniqueFiles = array_unique( $files, SORT_REGULAR );
 882                         $styleFiles = array();
 883                         foreach ( $uniqueFiles as $file ) {
 884                                 $styleFiles[] = $this->readStyleFile( $file, $flip, $context );
 885                         }
 886                         $styles[$media] = implode( "\n", $styleFiles );
 887                 }
 888                 return $styles;
 889         }
 890
 891         /**
 892          * Reads a style file.
 893          *
 894          * This method can be used as a callback for array_map()
 895          *
 896          * @param string $path File path of style file to read
 897          * @param bool $flip
 898          * @param ResourceLoaderContext $context (optional)
 899          *
 900          * @return string CSS data in script file
 901          * @throws MWException If the file doesn't exist
 902          */
 903         protected function readStyleFile( $path, $flip, $context = null ) {
 904                 $localPath = $this->getLocalPath( $path );
 905                 $remotePath = $this->getRemotePath( $path );
 906                 if ( !file_exists( $localPath ) ) {
 907                         $msg = __METHOD__ . ": style file not found: \"$localPath\"";
 908                         wfDebugLog( 'resourceloader', $msg );
 909                         throw new MWException( $msg );
 910                 }
 911
 912                 if ( $this->getStyleSheetLang( $localPath ) === 'less' ) {
 913                         $compiler = $this->getLessCompiler( $context );
 914                         $style = $this->compileLessFile( $localPath, $compiler );
 915                         $this->hasGeneratedStyles = true;
 916                 } else {
 917                         $style = file_get_contents( $localPath );
 918                 }
 919
 920                 if ( $flip ) {
 921                         $style = CSSJanus::transform( $style, true, false );
 922                 }
 923                 $localDir = dirname( $localPath );
 924                 $remoteDir = dirname( $remotePath );
 925                 // Get and register local file references
 926                 $localFileRefs = CSSMin::getAllLocalFileReferences( $style, $localDir );
 927                 foreach ( $localFileRefs as $file ) {
 928                         if ( file_exists( $file ) ) {
 929                                 $this->localFileRefs[] = $file;
 930                         } else {
 931                                 $this->missingLocalFileRefs[] = $file;
 932                         }
 933                 }
 934                 return CSSMin::remap(
 935                         $style, $localDir, $remoteDir, true
 936                 );
 937         }
 938
 939         /**
 940          * Get whether CSS for this module should be flipped
 941          * @param ResourceLoaderContext $context
 942          * @return bool
 943          */
 944         public function getFlip( $context ) {
 945                 return $context->getDirection() === 'rtl';
 946         }
 947
 948         /**
 949          * Get target(s) for the module, eg ['desktop'] or ['desktop', 'mobile']
 950          *
 951          * @return array Array of strings
 952          */
 953         public function getTargets() {
 954                 return $this->targets;
 955         }
 956
 957         /**
 958          * Compile a LESS file into CSS.
 959          *
 960          * Keeps track of all used files and adds them to localFileRefs.
 961          *
 962          * @since 1.22
 963          * @throws Exception If lessc encounters a parse error
 964          * @param string $fileName File path of LESS source
 965          * @param lessc $compiler Compiler to use, if not default
 966          * @return string CSS source
 967          */
 968         protected function compileLessFile( $fileName, $compiler = null ) {
 969                 if ( !$compiler ) {
 970                         $compiler = $this->getLessCompiler();
 971                 }
 972                 $result = $compiler->compileFile( $fileName );
 973                 $this->localFileRefs += array_keys( $compiler->allParsedFiles() );
 974                 return $result;
 975         }
 976
 977         /**
 978          * Get a LESS compiler instance for this module in given context.
 979          *
 980          * Just calls ResourceLoader::getLessCompiler() by default to get a global compiler.
 981          *
 982          * @param ResourceLoaderContext $context
 983          * @throws MWException
 984          * @since 1.24
 985          * @return lessc
 986          */
 987         protected function getLessCompiler( ResourceLoaderContext $context = null ) {
 988                 return ResourceLoader::getLessCompiler( $this->getConfig() );
 989         }
 990
 991         /**
 992          * Takes named templates by the module and returns an array mapping.
 993          * @return array of templates mapping template alias to content
 994          * @throws MWException
 995          */
 996         public function getTemplates() {
 997                 $templates = array();
 998
 999                 foreach ( $this->templates as $alias => $templatePath ) {
1000                         // Alias is optional
1001                         if ( is_int( $alias ) ) {
1002                                 $alias = $templatePath;
1003                         }
1004                         $localPath = $this->getLocalPath( $templatePath );
1005                         if ( file_exists( $localPath ) ) {
1006                                 $content = file_get_contents( $localPath );
1007                                 $templates[$alias] = $content;
1008                         } else {
1009                                 $msg = __METHOD__ . ": template file not found: \"$localPath\"";
1010                                 wfDebugLog( 'resourceloader', $msg );
1011                                 throw new MWException( $msg );
1012                         }
1013                 }
1014                 return $templates;
1015         }
1016 }