Include $IP in path passed to remap() so filesystem access will work properly

[mediawiki.git] / includes / resourceloader / ResourceLoader.php

<?php
/**
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @author Roan Kattouw
 * @author Trevor Parscal
 */

defined( 'MEDIAWIKI' ) || die( 1 );

/**
 * Dynamic JavaScript and CSS resource loading system.
 *
 * Most of the documention is on the MediaWiki documentation wiki starting at:
 *    http://www.mediawiki.org/wiki/ResourceLoader
 */
class ResourceLoader {

        /* Protected Static Members */

        /** @var {array} List of module name/ResourceLoaderModule object pairs */
        protected $modules = array();

        /* Protected Methods */

        /**
         * Loads information stored in the database about modules.
         * 
         * This method grabs modules dependencies from the database and updates modules objects.
         * 
         * This is not inside the module code because it's so much more performant to request all of the information at once
         * than it is to have each module requests its own information. This sacrifice of modularity yields a profound
         * performance improvement.
         * 
         * @param {array} $modules List of module names to preload information for
         * @param {ResourceLoaderContext} $context Context to load the information within
         */
        protected function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
                if ( !count( $modules ) ) {
                        return; // or else Database*::select() will explode, plus it's cheaper!
                }
                $dbr = wfGetDb( DB_SLAVE );
                $skin = $context->getSkin();
                $lang = $context->getLanguage();
                
                // Get file dependency information
                $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
                                'md_module' => $modules,
                                'md_skin' => $context->getSkin()
                        ), __METHOD__
                );

                // Set modules' dependecies             
                $modulesWithDeps = array();
                foreach ( $res as $row ) {
                        $this->modules[$row->md_module]->setFileDependencies( $skin,
                                FormatJson::decode( $row->md_deps, true )
                        );
                        $modulesWithDeps[] = $row->md_module;
                }

                // Register the absence of a dependency row too
                foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
                        $this->modules[$name]->setFileDependencies( $skin, array() );
                }
                
                // Get message blob mtimes. Only do this for modules with messages
                $modulesWithMessages = array();
                $modulesWithoutMessages = array();
                foreach ( $modules as $name ) {
                        if ( count( $this->modules[$name]->getMessages() ) ) {
                                $modulesWithMessages[] = $name;
                        } else {
                                $modulesWithoutMessages[] = $name;
                        }
                }
                if ( count( $modulesWithMessages ) ) {
                        $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
                                        'mr_resource' => $modulesWithMessages,
                                        'mr_lang' => $lang
                                ), __METHOD__
                        );
                        foreach ( $res as $row ) {
                                $this->modules[$row->mr_resource]->setMsgBlobMtime( $lang, $row->mr_timestamp );
                        }
                }
                foreach ( $modulesWithoutMessages as $name ) {
                        $this->modules[$name]->setMsgBlobMtime( $lang, 0 );
                }
        }

        /**
         * Runs JavaScript or CSS data through a filter, caching the filtered result for future calls.
         * 
         * Available filters are:
         *  - minify-js \see JSMin::minify
         *  - minify-css \see CSSMin::minify
         *  - flip-css \see CSSJanus::transform
         * 
         * If $data is empty, only contains whitespace or the filter was unknown, $data is returned unmodified.
         * 
         * @param {string} $filter Name of filter to run
         * @param {string} $data Text to filter, such as JavaScript or CSS text
         * @return {string} Filtered data
         */
        protected function filter( $filter, $data ) {
                global $wgMemc;
                
                wfProfileIn( __METHOD__ );

                // For empty/whitespace-only data or for unknown filters, don't perform any caching or processing
                if ( trim( $data ) === '' || !in_array( $filter, array( 'minify-js', 'minify-css', 'flip-css' ) ) ) {
                        wfProfileOut( __METHOD__ );
                        return $data;
                }

                // Try for Memcached hit
                $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
                if ( is_string( $cache = $wgMemc->get( $key ) ) ) {
                        wfProfileOut( __METHOD__ );
                        return $cache;
                }

                // Run the filter - we've already verified one of these will work
                try {
                        switch ( $filter ) {
                                case 'minify-js':
                                        $result = JSMin::minify( $data );
                                        break;
                                case 'minify-css':
                                        $result = CSSMin::minify( $data );
                                        break;
                                case 'flip-css':
                                        $result = CSSJanus::transform( $data, true, false );
                                        break;
                        }
                } catch ( Exception $exception ) {
                        throw new MWException( 'ResourceLoader filter error. Exception was thrown: ' . $exception->getMessage() );
                }

                // Save filtered text to Memcached
                $wgMemc->set( $key, $result );

                wfProfileOut( __METHOD__ );
                
                return $result;
        }

        /* Methods */

        /**
         * Registers core modules and runs registration hooks.
         */
        public function __construct() {
                global $IP;
                
                wfProfileIn( __METHOD__ );
                
                // Register core modules
                $this->register( include( "$IP/resources/Resources.php" ) );
                // Register extension modules
                wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
                
                wfProfileOut( __METHOD__ );
        }

        /**
         * Registers a module with the ResourceLoader system.
         * 
         * @param {mixed} $name string of name of module or array of name/object pairs
         * @param {ResourceLoaderModule} $object module object (optional when using multiple-registration calling style)
         * @throws {MWException} If a duplicate module registration is attempted
         * @throws {MWException} If something other than a ResourceLoaderModule is being registered
         * @return {bool} false if there were any errors, in which case one or more modules were not registered
         */
        public function register( $name, ResourceLoaderModule $object = null ) {

                wfProfileIn( __METHOD__ );

                // Allow multiple modules to be registered in one call
                if ( is_array( $name ) && !isset( $object ) ) {
                        foreach ( $name as $key => $value ) {
                                $this->register( $key, $value );
                        }

                        wfProfileOut( __METHOD__ );

                        return;
                }

                // Disallow duplicate registrations
                if ( isset( $this->modules[$name] ) ) {
                        // A module has already been registered by this name
                        throw new MWException(
                                'ResourceLoader duplicate registration error. Another module has already been registered as ' . $name
                        );
                }

                // Validate the input (type hinting lets null through)
                if ( !( $object instanceof ResourceLoaderModule ) ) {
                        throw new MWException( 'ResourceLoader invalid module error. Instances of ResourceLoaderModule expected.' );
                }

                // Attach module
                $this->modules[$name] = $object;
                $object->setName( $name );
                
                wfProfileOut( __METHOD__ );
        }

        /**
         * Gets a map of all modules and their options
         *
         * @return {array} array( modulename => ResourceLoaderModule )
         */
        public function getModules() {
                return $this->modules;
        }

        /**
         * Get the ResourceLoaderModule object for a given module name.
         *
         * @param {string} $name module name
         * @return {mixed} ResourceLoaderModule if module has been registered, null otherwise
         */
        public function getModule( $name ) {
                return isset( $this->modules[$name] ) ? $this->modules[$name] : null;
        }

        /**
         * Outputs a response to a resource load-request, including a content-type header.
         *
         * @param {ResourceLoaderContext} $context Context in which a response should be formed
         */
        public function respond( ResourceLoaderContext $context ) {
                global $wgResourceLoaderMaxage, $wgCacheEpoch;

                wfProfileIn( __METHOD__ );

                // Split requested modules into two groups, modules and missing
                $modules = array();
                $missing = array();
                foreach ( $context->getModules() as $name ) {
                        if ( isset( $this->modules[$name] ) ) {
                                $modules[$name] = $this->modules[$name];
                        } else {
                                $missing[] = $name;
                        }
                }

                // If a version wasn't specified we need a shorter expiry time for updates to propagate to clients quickly
                if ( is_null( $context->getVersion() ) ) {
                        $maxage  = $wgResourceLoaderMaxage['unversioned']['client'];
                        $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
                }
                // If a version was specified we can use a longer expiry time since changing version numbers causes cache misses
                else {
                        $maxage  = $wgResourceLoaderMaxage['versioned']['client'];
                        $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
                }

                // Preload information needed to the mtime calculation below
                $this->preloadModuleInfo( array_keys( $modules ), $context );

                wfProfileIn( __METHOD__.'-getModifiedTime' );

                // To send Last-Modified and support If-Modified-Since, we need to detect the last modified time
                $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
                foreach ( $modules as $module ) {
                        // Bypass squid cache if the request includes any private modules
                        if ( $module->getGroup() === 'private' ) {
                                $smaxage = 0;
                        }
                        // Calculate maximum modified time
                        $mtime = max( $mtime, $module->getModifiedTime( $context ) );
                }

                wfProfileOut( __METHOD__.'-getModifiedTime' );

                header( 'Content-Type: ' . ( $context->getOnly() === 'styles' ? 'text/css' : 'text/javascript' ) );
                header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
                header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
                header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );

                // If there's an If-Modified-Since header, respond with a 304 appropriately
                $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
                if ( $ims !== false && $mtime <= wfTimestamp( TS_UNIX, $ims ) ) {
                        header( 'HTTP/1.0 304 Not Modified' );
                        header( 'Status: 304 Not Modified' );
                        wfProfileOut( __METHOD__ );
                        return;
                }
                
                // Generate a response
                $response = $this->makeModuleResponse( $context, $modules, $missing );

                // Tack on PHP warnings as a comment in debug mode
                if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
                        $response .= "/*\n$warnings\n*/";
                }

                // Clear any warnings from the buffer
                ob_clean();
                echo $response;

                wfProfileOut( __METHOD__ );
        }

        /**
         * Generates code for a response
         * 
         * @param {ResourceLoaderContext} $context Context in which to generate a response
         * @param {array} $modules List of module objects keyed by module name
         * @param {array} $missing List of unavailable modules (optional)
         * @return {string} Response data
         */
        public function makeModuleResponse( ResourceLoaderContext $context, array $modules, $missing = array() ) {
                // Pre-fetch blobs
                $blobs = $context->shouldIncludeMessages() ?
                        MessageBlobStore::get( $this, $modules, $context->getLanguage() ) : array();

                // Generate output
                $out = '';
                foreach ( $modules as $name => $module ) {

                        wfProfileIn( __METHOD__ . '-' . $name );

                        // Scripts
                        $scripts = '';
                        if ( $context->shouldIncludeScripts() ) {
                                $scripts .= $module->getScript( $context ) . "\n";
                        }

                        // Styles
                        $styles = array();
                        if ( $context->shouldIncludeStyles() && ( count( $styles = $module->getStyles( $context ) ) ) ) {
                                // Flip CSS on a per-module basis
                                if ( $this->modules[$name]->getFlip( $context ) ) {
                                        foreach ( $styles as $media => $style ) {
                                                $styles[$media] = $this->filter( 'flip-css', $style );
                                        }
                                }
                        }

                        // Messages
                        $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';

                        // Append output
                        switch ( $context->getOnly() ) {
                                case 'scripts':
                                        $out .= $scripts;
                                        break;
                                case 'styles':
                                        $out .= self::makeCombinedStyles( $styles );
                                        break;
                                case 'messages':
                                        $out .= self::makeMessageSetScript( $messages );
                                        break;
                                default:
                                        // Minify CSS before embedding in mediaWiki.loader.implement call (unless in debug mode)
                                        if ( !$context->getDebug() ) {
                                                foreach ( $styles as $media => $style ) {
                                                        $styles[$media] = $this->filter( 'minify-css', $style );
                                                }
                                        }
                                        $out .= self::makeLoaderImplementScript( $name, $scripts, $styles, $messages );
                                        break;
                        }

                        wfProfileOut( __METHOD__ . '-' . $name );
                }

                // Update module states
                if ( $context->shouldIncludeScripts() ) {
                        // Set the state of modules loaded as only scripts to ready
                        if ( count( $modules ) && $context->getOnly() === 'scripts' && !isset( $modules['startup'] ) ) {
                                $out .= self::makeLoaderStateScript( array_fill_keys( array_keys( $modules ), 'ready' ) );
                        }
                        // Set the state of modules which were requested but unavailable as missing
                        if ( is_array( $missing ) && count( $missing ) ) {
                                $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
                        }
                }

                if ( $context->getDebug() ) {
                        return $out;
                } else {
                        if ( $context->getOnly() === 'styles' ) {
                                return $this->filter( 'minify-css', $out );
                        } else {
                                return $this->filter( 'minify-js', $out );
                        }
                }
        }

        /* Static Methods */

        public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
                if ( is_array( $scripts ) ) {
                        $scripts = implode( $scripts, "\n" );
                }
                if ( is_array( $styles ) ) {
                        $styles = count( $styles ) ? FormatJson::encode( $styles ) : 'null';
                }
                if ( is_array( $messages ) ) {
                        $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
                }
                return "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
        }

        public static function makeMessageSetScript( $messages ) {
                if ( is_array( $messages ) ) {
                        $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
                }
                return "mediaWiki.msg.set( $messages );\n";
        }

        public static function makeCombinedStyles( array $styles ) {
                $out = '';
                foreach ( $styles as $media => $style ) {
                        $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
                }
                return $out;
        }

        public static function makeLoaderStateScript( $name, $state = null ) {
                if ( is_array( $name ) ) {
                        $statuses = FormatJson::encode( $name );
                        return "mediaWiki.loader.state( $statuses );\n";
                } else {
                        $name = Xml::escapeJsString( $name );
                        $state = Xml::escapeJsString( $state );
                        return "mediaWiki.loader.state( '$name', '$state' );\n";
                }
        }

        public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
                $name = Xml::escapeJsString( $name );
                $version = (int) $version > 1 ? (int) $version : 1;
                $dependencies = FormatJson::encode( $dependencies );
                $group = FormatJson::encode( $group );
                $script = str_replace( "\n", "\n\t", trim( $script ) );
                return "( function( name, version, dependencies, group ) {\n\t$script\n} )" .
                        "( '$name', $version, $dependencies, $group );\n";
        }

        public static function makeLoaderRegisterScript( $name, $version = null, $dependencies = null, $group = null ) {
                if ( is_array( $name ) ) {
                        $registrations = FormatJson::encode( $name );
                        return "mediaWiki.loader.register( $registrations );\n";
                } else {
                        $name = Xml::escapeJsString( $name );
                        $version = (int) $version > 1 ? (int) $version : 1;
                        $dependencies = FormatJson::encode( $dependencies );
                        $group = FormatJson::encode( $group );
                        return "mediaWiki.loader.register( '$name', $version, $dependencies, $group );\n";
                }
        }

        public static function makeLoaderConditionalScript( $script ) {
                $script = str_replace( "\n", "\n\t", trim( $script ) );
                return "if ( window.mediaWiki ) {\n\t$script\n}\n";
        }

        public static function makeConfigSetScript( array $configuration ) {
                $configuration = FormatJson::encode( $configuration );
                return "mediaWiki.config.set( $configuration );\n";
        }
}