ResourceLoaderFileModule.php

Go to the documentation of this file.

<?php
class ResourceLoaderFileModule extends ResourceLoaderModule {
 
    protected $localBasePath = '';
 
    protected $remoteBasePath = '';
 
    protected $templates = [];
 
    protected $scripts = [];
 
    protected $languageScripts = [];
 
    protected $skinScripts = [];
 
    protected $debugScripts = [];
 
    protected $styles = [];
 
    protected $skinStyles = [];
 
    protected $packageFiles = null;
 
    private $expandedPackageFiles = [];
 
    protected $dependencies = [];
 
    protected $skipFunction = null;
 
    protected $messages = [];
 
    protected $group;
 
    protected $debugRaw = true;
 
    protected $targets = [ 'desktop' ];
 
    protected $noflip = false;
 
    protected $hasGeneratedStyles = false;
 
    protected $localFileRefs = [];
 
    protected $missingLocalFileRefs = [];
 
    public function __construct(
        $options = [],
        $localBasePath = null,
        $remoteBasePath = null
    ) {
        // Flag to decide whether to automagically add the mediawiki.template module
        $hasTemplates = false;
        // localBasePath and remoteBasePath both have unbelievably long fallback chains
        // and need to be handled separately.
        list( $this->localBasePath, $this->remoteBasePath ) =
            self::extractBasePaths( $options, $localBasePath, $remoteBasePath );
 
        // Extract, validate and normalise remaining options
        foreach ( $options as $member => $option ) {
            switch ( $member ) {
                // Lists of file paths
                case 'scripts':
                case 'debugScripts':
                case 'styles':
                case 'packageFiles':
                    $this->{$member} = is_array( $option ) ? $option : [ $option ];
                    break;
                case 'templates':
                    $hasTemplates = true;
                    $this->{$member} = is_array( $option ) ? $option : [ $option ];
                    break;
                // Collated lists of file paths
                case 'languageScripts':
                case 'skinScripts':
                case 'skinStyles':
                    if ( !is_array( $option ) ) {
                        throw new InvalidArgumentException(
                            "Invalid collated file path list error. " .
                            "'$option' given, array expected."
                        );
                    }
                    foreach ( $option as $key => $value ) {
                        if ( !is_string( $key ) ) {
                            throw new InvalidArgumentException(
                                "Invalid collated file path list key error. " .
                                "'$key' given, string expected."
                            );
                        }
                        $this->{$member}[$key] = is_array( $value ) ? $value : [ $value ];
                    }
                    break;
                case 'deprecated':
                    $this->deprecated = $option;
                    break;
                // Lists of strings
                case 'dependencies':
                case 'messages':
                case 'targets':
                    // Normalise
                    $option = array_values( array_unique( (array)$option ) );
                    sort( $option );
 
                    $this->{$member} = $option;
                    break;
                // Single strings
                case 'group':
                case 'skipFunction':
                    $this->{$member} = (string)$option;
                    break;
                // Single booleans
                case 'debugRaw':
                case 'noflip':
                    $this->{$member} = (bool)$option;
                    break;
            }
        }
        if ( isset( $options['scripts'] ) && isset( $options['packageFiles'] ) ) {
            throw new InvalidArgumentException( "A module may not set both 'scripts' and 'packageFiles'" );
        }
        if ( $hasTemplates ) {
            $this->dependencies[] = 'mediawiki.template';
            // Ensure relevant template compiler module gets loaded
            foreach ( $this->templates as $alias => $templatePath ) {
                if ( is_int( $alias ) ) {
                    $alias = $this->getPath( $templatePath );
                }
                $suffix = explode( '.', $alias );
                $suffix = end( $suffix );
                $compilerModule = 'mediawiki.template.' . $suffix;
                if ( $suffix !== 'html' && !in_array( $compilerModule, $this->dependencies ) ) {
                    $this->dependencies[] = $compilerModule;
                }
            }
        }
    }
 
    public static function extractBasePaths(
        $options = [],
        $localBasePath = null,
        $remoteBasePath = null
    ) {
        global $IP, $wgResourceBasePath;
 
        // The different ways these checks are done, and their ordering, look very silly,
        // but were preserved for backwards-compatibility just in case. Tread lightly.
 
        if ( $localBasePath === null ) {
            $localBasePath = $IP;
        }
        if ( $remoteBasePath === null ) {
            $remoteBasePath = $wgResourceBasePath;
        }
 
        if ( isset( $options['remoteExtPath'] ) ) {
            global $wgExtensionAssetsPath;
            $remoteBasePath = $wgExtensionAssetsPath . '/' . $options['remoteExtPath'];
        }
 
        if ( isset( $options['remoteSkinPath'] ) ) {
            global $wgStylePath;
            $remoteBasePath = $wgStylePath . '/' . $options['remoteSkinPath'];
        }
 
        if ( array_key_exists( 'localBasePath', $options ) ) {
            $localBasePath = (string)$options['localBasePath'];
        }
 
        if ( array_key_exists( 'remoteBasePath', $options ) ) {
            $remoteBasePath = (string)$options['remoteBasePath'];
        }
 
        return [ $localBasePath, $remoteBasePath ];
    }
 
    public function getScript( ResourceLoaderContext $context ) {
        $deprecationScript = $this->getDeprecationInformation( $context );
        if ( $this->packageFiles !== null ) {
            $packageFiles = $this->getPackageFiles( $context );
            if ( $deprecationScript ) {
                $mainFile =& $packageFiles['files'][$packageFiles['main']];
                $mainFile['content'] = $deprecationScript . $mainFile['content'];
            }
            return $packageFiles;
        }
 
        $files = $this->getScriptFiles( $context );
        return $deprecationScript . $this->readScriptFiles( $files );
    }
 
    public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
        $urls = [];
        foreach ( $this->getScriptFiles( $context ) as $file ) {
            $urls[] = OutputPage::transformResourcePath(
                $this->getConfig(),
                $this->getRemotePath( $file )
            );
        }
        return $urls;
    }
 
    public function supportsURLLoading() {
        // If package files are involved, don't support URL loading, because that breaks
        // scoped require() functions
        return $this->debugRaw && !$this->packageFiles;
    }
 
    public function getStyles( ResourceLoaderContext $context ) {
        $styles = $this->readStyleFiles(
            $this->getStyleFiles( $context ),
            $this->getFlip( $context ),
            $context
        );
        // Collect referenced files
        $this->saveFileDependencies( $context, $this->localFileRefs );
 
        return $styles;
    }
 
    public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
        if ( $this->hasGeneratedStyles ) {
            // Do the default behaviour of returning a url back to load.php
            // but with only=styles.
            return parent::getStyleURLsForDebug( $context );
        }
        // Our module consists entirely of real css files,
        // in debug mode we can load those directly.
        $urls = [];
        foreach ( $this->getStyleFiles( $context ) as $mediaType => $list ) {
            $urls[$mediaType] = [];
            foreach ( $list as $file ) {
                $urls[$mediaType][] = OutputPage::transformResourcePath(
                    $this->getConfig(),
                    $this->getRemotePath( $file )
                );
            }
        }
        return $urls;
    }
 
    public function getMessages() {
        return $this->messages;
    }
 
    public function getGroup() {
        return $this->group;
    }
 
    public function getDependencies( ResourceLoaderContext $context = null ) {
        return $this->dependencies;
    }
 
    public function getSkipFunction() {
        if ( !$this->skipFunction ) {
            return null;
        }
 
        $localPath = $this->getLocalPath( $this->skipFunction );
        if ( !file_exists( $localPath ) ) {
            throw new MWException( __METHOD__ . ": skip function file not found: \"$localPath\"" );
        }
        $contents = $this->stripBom( file_get_contents( $localPath ) );
        return $contents;
    }
 
    public function enableModuleContentVersion() {
        return false;
    }
 
    private function getFileHashes( ResourceLoaderContext $context ) {
        $files = [];
 
        // Flatten style files into $files
        $styles = self::collateFilePathListByOption( $this->styles, 'media', 'all' );
        foreach ( $styles as $styleFiles ) {
            $files = array_merge( $files, $styleFiles );
        }
 
        $skinFiles = self::collateFilePathListByOption(
            self::tryForKey( $this->skinStyles, $context->getSkin(), 'default' ),
            'media',
            'all'
        );
        foreach ( $skinFiles as $styleFiles ) {
            $files = array_merge( $files, $styleFiles );
        }
 
        // Extract file names for package files
        $expandedPackageFiles = $this->expandPackageFiles( $context );
        $packageFiles = $expandedPackageFiles ?
            array_filter( array_map( function ( $fileInfo ) {
                return $fileInfo['filePath'] ?? null;
            }, $expandedPackageFiles['files'] ) ) :
            [];
 
        // Final merge, this should result in a master list of dependent files
        $files = array_merge(
            $files,
            $packageFiles,
            $this->scripts,
            $this->templates,
            $context->getDebug() ? $this->debugScripts : [],
            $this->getLanguageScripts( $context->getLanguage() ),
            self::tryForKey( $this->skinScripts, $context->getSkin(), 'default' )
        );
        if ( $this->skipFunction ) {
            $files[] = $this->skipFunction;
        }
        $files = array_map( [ $this, 'getLocalPath' ], $files );
        // File deps need to be treated separately because they're already prefixed
        $files = array_merge( $files, $this->getFileDependencies( $context ) );
        // Filter out any duplicates from getFileDependencies() and others.
        // Most commonly introduced by compileLessFile(), which always includes the
        // entry point Less file we already know about.
        $files = array_values( array_unique( $files ) );
 
        // Don't include keys or file paths here, only the hashes. Including that would needlessly
        // cause global cache invalidation when files move or if e.g. the MediaWiki path changes.
        // Any significant ordering is already detected by the definition summary.
        return array_map( [ __CLASS__, 'safeFileHash' ], $files );
    }
 
    public function getDefinitionSummary( ResourceLoaderContext $context ) {
        $summary = parent::getDefinitionSummary( $context );
 
        $options = [];
        foreach ( [
            // The following properties are omitted because they don't affect the module reponse:
            // - localBasePath (Per T104950; Changes when absolute directory name changes. If
            //    this affects 'scripts' and other file paths, getFileHashes accounts for that.)
            // - remoteBasePath (Per T104950)
            // - dependencies (provided via startup module)
            // - targets
            // - group (provided via startup module)
            'scripts',
            'debugScripts',
            'styles',
            'languageScripts',
            'skinScripts',
            'skinStyles',
            'messages',
            'templates',
            'skipFunction',
            'debugRaw',
        ] as $member ) {
            $options[$member] = $this->{$member};
        }
 
        $packageFiles = $this->expandPackageFiles( $context );
        if ( $packageFiles ) {
            // Extract the minimum needed:
            // - The 'main' pointer (included as-is).
            // - The 'files' array, simplied to only which files exist (the keys of
            //   this array), and something that represents their non-file content.
            //   For packaged files that reflect files directly from disk, the
            //   'getFileHashes' method tracks this already.
            //   It is important that the keys of the 'files' array are preserved,
            //   as they affect the module output.
            $packageFiles['files'] = array_map( function ( $fileInfo ) {
                return $fileInfo['definitionSummary'] ?? ( $fileInfo['content'] ?? null );
            }, $packageFiles['files'] );
        }
 
        $summary[] = [
            'options' => $options,
            'packageFiles' => $packageFiles,
            'fileHashes' => $this->getFileHashes( $context ),
            'messageBlob' => $this->getMessageBlob( $context ),
        ];
 
        $lessVars = $this->getLessVars( $context );
        if ( $lessVars ) {
            $summary[] = [ 'lessVars' => $lessVars ];
        }
 
        return $summary;
    }
 
    protected function getPath( $path ) {
        if ( $path instanceof ResourceLoaderFilePath ) {
            return $path->getPath();
        }
 
        return $path;
    }
 
    protected function getLocalPath( $path ) {
        if ( $path instanceof ResourceLoaderFilePath ) {
            return $path->getLocalPath();
        }
 
        return "{$this->localBasePath}/$path";
    }
 
    protected function getRemotePath( $path ) {
        if ( $path instanceof ResourceLoaderFilePath ) {
            return $path->getRemotePath();
        }
 
        return "{$this->remoteBasePath}/$path";
    }
 
    public function getStyleSheetLang( $path ) {
        return preg_match( '/\.less$/i', $path ) ? 'less' : 'css';
    }
 
    public static function getPackageFileType( $path ) {
        if ( preg_match( '/\.json$/i', $path ) ) {
            return 'data';
        }
        return 'script';
    }
 
    protected static function collateFilePathListByOption( array $list, $option, $default ) {
        $collatedFiles = [];
        foreach ( (array)$list as $key => $value ) {
            if ( is_int( $key ) ) {
                // File name as the value
                if ( !isset( $collatedFiles[$default] ) ) {
                    $collatedFiles[$default] = [];
                }
                $collatedFiles[$default][] = $value;
            } elseif ( is_array( $value ) ) {
                // File name as the key, options array as the value
                $optionValue = $value[$option] ?? $default;
                if ( !isset( $collatedFiles[$optionValue] ) ) {
                    $collatedFiles[$optionValue] = [];
                }
                $collatedFiles[$optionValue][] = $key;
            }
        }
        return $collatedFiles;
    }
 
    protected static function tryForKey( array $list, $key, $fallback = null ) {
        if ( isset( $list[$key] ) && is_array( $list[$key] ) ) {
            return $list[$key];
        } elseif ( is_string( $fallback )
            && isset( $list[$fallback] )
            && is_array( $list[$fallback] )
        ) {
            return $list[$fallback];
        }
        return [];
    }
 
    private function getScriptFiles( ResourceLoaderContext $context ) {
        $files = array_merge(
            $this->scripts,
            $this->getLanguageScripts( $context->getLanguage() ),
            self::tryForKey( $this->skinScripts, $context->getSkin(), 'default' )
        );
        if ( $context->getDebug() ) {
            $files = array_merge( $files, $this->debugScripts );
        }
 
        return array_unique( $files, SORT_REGULAR );
    }
 
    private function getLanguageScripts( $lang ) {
        $scripts = self::tryForKey( $this->languageScripts, $lang );
        if ( $scripts ) {
            return $scripts;
        }
        $fallbacks = Language::getFallbacksFor( $lang );
        foreach ( $fallbacks as $lang ) {
            $scripts = self::tryForKey( $this->languageScripts, $lang );
            if ( $scripts ) {
                return $scripts;
            }
        }
 
        return [];
    }
 
    public function getStyleFiles( ResourceLoaderContext $context ) {
        return array_merge_recursive(
            self::collateFilePathListByOption( $this->styles, 'media', 'all' ),
            self::collateFilePathListByOption(
                self::tryForKey( $this->skinStyles, $context->getSkin(), 'default' ),
                'media',
                'all'
            )
        );
    }
 
    protected function getSkinStyleFiles( $skinName ) {
        return self::collateFilePathListByOption(
            self::tryForKey( $this->skinStyles, $skinName ),
            'media',
            'all'
        );
    }
 
    protected function getAllSkinStyleFiles() {
        $styleFiles = [];
        $internalSkinNames = array_keys( Skin::getSkinNames() );
        $internalSkinNames[] = 'default';
 
        foreach ( $internalSkinNames as $internalSkinName ) {
            $styleFiles = array_merge_recursive(
                $styleFiles,
                $this->getSkinStyleFiles( $internalSkinName )
            );
        }
 
        return $styleFiles;
    }
 
    public function getAllStyleFiles() {
        $collatedStyleFiles = array_merge_recursive(
            self::collateFilePathListByOption( $this->styles, 'media', 'all' ),
            $this->getAllSkinStyleFiles()
        );
 
        $result = [];
 
        foreach ( $collatedStyleFiles as $media => $styleFiles ) {
            foreach ( $styleFiles as $styleFile ) {
                $result[] = $this->getLocalPath( $styleFile );
            }
        }
 
        return $result;
    }
 
    private function readScriptFiles( array $scripts ) {
        if ( empty( $scripts ) ) {
            return '';
        }
        $js = '';
        foreach ( array_unique( $scripts, SORT_REGULAR ) as $fileName ) {
            $localPath = $this->getLocalPath( $fileName );
            if ( !file_exists( $localPath ) ) {
                throw new MWException( __METHOD__ . ": script file not found: \"$localPath\"" );
            }
            $contents = $this->stripBom( file_get_contents( $localPath ) );
            $js .= $contents . "\n";
        }
        return $js;
    }
 
    public function readStyleFiles( array $styles, $flip, ResourceLoaderContext $context ) {
        if ( !$styles ) {
            return [];
        }
        foreach ( $styles as $media => $files ) {
            $uniqueFiles = array_unique( $files, SORT_REGULAR );
            $styleFiles = [];
            foreach ( $uniqueFiles as $file ) {
                $styleFiles[] = $this->readStyleFile( $file, $flip, $context );
            }
            $styles[$media] = implode( "\n", $styleFiles );
        }
        return $styles;
    }
 
    protected function readStyleFile( $path, $flip, ResourceLoaderContext $context ) {
        $localPath = $this->getLocalPath( $path );
        $remotePath = $this->getRemotePath( $path );
        if ( !file_exists( $localPath ) ) {
            $msg = __METHOD__ . ": style file not found: \"$localPath\"";
            wfDebugLog( 'resourceloader', $msg );
            throw new MWException( $msg );
        }
 
        if ( $this->getStyleSheetLang( $localPath ) === 'less' ) {
            $style = $this->compileLessFile( $localPath, $context );
            $this->hasGeneratedStyles = true;
        } else {
            $style = $this->stripBom( file_get_contents( $localPath ) );
        }
 
        if ( $flip ) {
            $style = CSSJanus::transform( $style, true, false );
        }
        $localDir = dirname( $localPath );
        $remoteDir = dirname( $remotePath );
        // Get and register local file references
        $localFileRefs = CSSMin::getLocalFileReferences( $style, $localDir );
        foreach ( $localFileRefs as $file ) {
            if ( file_exists( $file ) ) {
                $this->localFileRefs[] = $file;
            } else {
                $this->missingLocalFileRefs[] = $file;
            }
        }
        // Don't cache this call. remap() ensures data URIs embeds are up to date,
        // and urls contain correct content hashes in their query string. (T128668)
        return CSSMin::remap( $style, $localDir, $remoteDir, true );
    }
 
    public function getFlip( ResourceLoaderContext $context ) {
        return $context->getDirection() === 'rtl' && !$this->noflip;
    }
 
    public function getTargets() {
        return $this->targets;
    }
 
    public function getType() {
        $canBeStylesOnly = !(
            // All options except 'styles', 'skinStyles' and 'debugRaw'
            $this->scripts
            || $this->debugScripts
            || $this->templates
            || $this->languageScripts
            || $this->skinScripts
            || $this->dependencies
            || $this->messages
            || $this->skipFunction
            || $this->packageFiles
        );
        return $canBeStylesOnly ? self::LOAD_STYLES : self::LOAD_GENERAL;
    }
 
    protected function compileLessFile( $fileName, ResourceLoaderContext $context ) {
        static $cache;
 
        if ( !$cache ) {
            $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
        }
 
        $vars = $this->getLessVars( $context );
        // Construct a cache key from the LESS file name, and a hash digest
        // of the LESS variables used for compilation.
        ksort( $vars );
        $varsHash = hash( 'md4', serialize( $vars ) );
        $cacheKey = $cache->makeGlobalKey( 'LESS', $fileName, $varsHash );
        $cachedCompile = $cache->get( $cacheKey );
 
        // If we got a cached value, we have to validate it by getting a
        // checksum of all the files that were loaded by the parser and
        // ensuring it matches the cached entry's.
        if ( isset( $cachedCompile['hash'] ) ) {
            $contentHash = FileContentsHasher::getFileContentsHash( $cachedCompile['files'] );
            if ( $contentHash === $cachedCompile['hash'] ) {
                $this->localFileRefs = array_merge( $this->localFileRefs, $cachedCompile['files'] );
                return $cachedCompile['css'];
            }
        }
 
        $compiler = $context->getResourceLoader()->getLessCompiler( $vars );
        $css = $compiler->parseFile( $fileName )->getCss();
        $files = $compiler->AllParsedFiles();
        $this->localFileRefs = array_merge( $this->localFileRefs, $files );
 
        // Cache for 24 hours (86400 seconds).
        $cache->set( $cacheKey, [
            'css'   => $css,
            'files' => $files,
            'hash'  => FileContentsHasher::getFileContentsHash( $files ),
        ], 3600 * 24 );
 
        return $css;
    }
 
    public function getTemplates() {
        $templates = [];
 
        foreach ( $this->templates as $alias => $templatePath ) {
            // Alias is optional
            if ( is_int( $alias ) ) {
                $alias = $this->getPath( $templatePath );
            }
            $localPath = $this->getLocalPath( $templatePath );
            if ( file_exists( $localPath ) ) {
                $content = file_get_contents( $localPath );
                $templates[$alias] = $this->stripBom( $content );
            } else {
                $msg = __METHOD__ . ": template file not found: \"$localPath\"";
                wfDebugLog( 'resourceloader', $msg );
                throw new MWException( $msg );
            }
        }
        return $templates;
    }
 
    private function expandPackageFiles( ResourceLoaderContext $context ) {
        $hash = $context->getHash();
        if ( isset( $this->expandedPackageFiles[$hash] ) ) {
            return $this->expandedPackageFiles[$hash];
        }
        if ( $this->packageFiles === null ) {
            return null;
        }
        $expandedFiles = [];
        $mainFile = null;
 
        foreach ( $this->packageFiles as $alias => $fileInfo ) {
            if ( is_string( $fileInfo ) ) {
                $fileInfo = [ 'name' => $fileInfo, 'file' => $fileInfo ];
            } elseif ( !isset( $fileInfo['name'] ) ) {
                $msg = __METHOD__ . ": invalid package file definition for module " .
                    "\"{$this->getName()}\": 'name' key is required when value is not a string";
                wfDebugLog( 'resourceloader', $msg );
                throw new MWException( $msg );
            }
 
            // Infer type from alias if needed
            $type = $fileInfo['type'] ?? self::getPackageFileType( $fileInfo['name'] );
            $expanded = [ 'type' => $type ];
            if ( !empty( $fileInfo['main'] ) ) {
                $mainFile = $fileInfo['name'];
                if ( $type !== 'script' ) {
                    $msg = __METHOD__ . ": invalid package file definition for module " .
                        "\"{$this->getName()}\": main file \"$mainFile\" must be of type \"script\", not \"$type\"";
                    wfDebugLog( 'resourceloader', $msg );
                    throw new MWException( $msg );
                }
            }
 
            // Perform expansions (except 'file' and 'callback'), creating one of these keys:
            // - 'content': literal value.
            // - 'filePath': content to be read from a file.
            // - 'callback': content computed by a callable.
            if ( isset( $fileInfo['content'] ) ) {
                $expanded['content'] = $fileInfo['content'];
            } elseif ( isset( $fileInfo['file'] ) ) {
                $expanded['filePath'] = $fileInfo['file'];
            } elseif ( isset( $fileInfo['callback'] ) ) {
                if ( !is_callable( $fileInfo['callback'] ) ) {
                    $msg = __METHOD__ . ": invalid callback for package file \"{$fileInfo['name']}\"" .
                        " in module \"{$this->getName()}\"";
                    wfDebugLog( 'resourceloader', $msg );
                    throw new MWException( $msg );
                }
                if ( isset( $fileInfo['versionCallback'] ) ) {
                    if ( !is_callable( $fileInfo['versionCallback'] ) ) {
                        throw new MWException( __METHOD__ . ": invalid versionCallback for file" .
                            " \"{$fileInfo['name']}\" in module \"{$this->getName()}\"" );
                    }
                    $expanded['definitionSummary'] =
                        ( $fileInfo['versionCallback'] )( $context, $this->getConfig() );
                    // Don't invoke 'callback' here as it may be expensive (T223260).
                    $expanded['callback'] = $fileInfo['callback'];
                } else {
                    $expanded['content'] = ( $fileInfo['callback'] )( $context, $this->getConfig() );
                }
            } elseif ( isset( $fileInfo['config'] ) ) {
                if ( $type !== 'data' ) {
                    $msg = __METHOD__ . ": invalid use of \"config\" for package file \"{$fileInfo['name']}\" " .
                        "in module \"{$this->getName()}\": type must be \"data\" but is \"$type\"";
                    wfDebugLog( 'resourceloader', $msg );
                    throw new MWException( $msg );
                }
                $expandedConfig = [];
                foreach ( $fileInfo['config'] as $key => $var ) {
                    $expandedConfig[ is_numeric( $key ) ? $var : $key ] = $this->getConfig()->get( $var );
                }
                $expanded['content'] = $expandedConfig;
            } elseif ( !empty( $fileInfo['main'] ) ) {
                // [ 'name' => 'foo.js', 'main' => true ] is shorthand
                $expanded['filePath'] = $fileInfo['name'];
            } else {
                $msg = __METHOD__ . ": invalid package file definition for \"{$fileInfo['name']}\" " .
                    "in module \"{$this->getName()}\": one of \"file\", \"content\", \"callback\" or \"config\" " .
                    "must be set";
                wfDebugLog( 'resourceloader', $msg );
                throw new MWException( $msg );
            }
 
            $expandedFiles[$fileInfo['name']] = $expanded;
        }
 
        if ( $expandedFiles && $mainFile === null ) {
            // The first package file that is a script is the main file
            foreach ( $expandedFiles as $path => &$file ) {
                if ( $file['type'] === 'script' ) {
                    $mainFile = $path;
                    break;
                }
            }
        }
 
        $result = [
            'main' => $mainFile,
            'files' => $expandedFiles
        ];
 
        $this->expandedPackageFiles[$hash] = $result;
        return $result;
    }
 
    public function getPackageFiles( ResourceLoaderContext $context ) {
        if ( $this->packageFiles === null ) {
            return null;
        }
        $expandedPackageFiles = $this->expandPackageFiles( $context );
 
        // Expand file contents
        foreach ( $expandedPackageFiles['files'] as &$fileInfo ) {
            // Turn any 'filePath' or 'callback' key into actual 'content',
            // and remove the key after that.
            if ( isset( $fileInfo['filePath'] ) ) {
                $localPath = $this->getLocalPath( $fileInfo['filePath'] );
                if ( !file_exists( $localPath ) ) {
                    $msg = __METHOD__ . ": package file not found: \"$localPath\"" .
                        " in module \"{$this->getName()}\"";
                    wfDebugLog( 'resourceloader', $msg );
                    throw new MWException( $msg );
                }
                $content = $this->stripBom( file_get_contents( $localPath ) );
                if ( $fileInfo['type'] === 'data' ) {
                    $content = json_decode( $content );
                }
                $fileInfo['content'] = $content;
                unset( $fileInfo['filePath'] );
            } elseif ( isset( $fileInfo['callback'] ) ) {
                $fileInfo['content'] = ( $fileInfo['callback'] )( $context, $this->getConfig() );
                unset( $fileInfo['callback'] );
            }
 
            // Not needed for client response, exists for getDefinitionSummary().
            unset( $fileInfo['definitionSummary'] );
        }
 
        return $expandedPackageFiles;
    }
 
    protected function stripBom( $input ) {
        if ( substr_compare( "\xef\xbb\xbf", $input, 0, 3 ) === 0 ) {
            return substr( $input, 3 );
        }
        return $input;
    }
}