ResourceLoaderClientHtml.php

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<?php
use Wikimedia\WrappedString;
use Wikimedia\WrappedStringList;
 
class ResourceLoaderClientHtml {
 
    private $context;
 
    private $resourceLoader;
 
    private $options;
 
    private $config = [];
 
    private $modules = [];
 
    private $moduleStyles = [];
 
    private $exemptStates = [];
 
    private $data;
 
    public function __construct( ResourceLoaderContext $context, array $options = [] ) {
        $this->context = $context;
        $this->resourceLoader = $context->getResourceLoader();
        $this->options = $options + [
            'target' => null,
            'safemode' => null,
            'nonce' => null,
        ];
    }
 
    public function setConfig( array $vars ) {
        foreach ( $vars as $key => $value ) {
            $this->config[$key] = $value;
        }
    }
 
    public function setModules( array $modules ) {
        $this->modules = $modules;
    }
 
    public function setModuleStyles( array $modules ) {
        $this->moduleStyles = $modules;
    }
 
    public function setExemptStates( array $states ) {
        $this->exemptStates = $states;
    }
 
    private function getData() {
        if ( $this->data ) {
            // @codeCoverageIgnoreStart
            return $this->data;
            // @codeCoverageIgnoreEnd
        }
 
        $rl = $this->resourceLoader;
        $data = [
            'states' => [
                // moduleName => state
            ],
            'general' => [],
            'styles' => [],
            // Embedding for private modules
            'embed' => [
                'styles' => [],
                'general' => [],
            ],
            // Deprecations for style-only modules
            'styleDeprecations' => [],
        ];
 
        foreach ( $this->modules as $name ) {
            $module = $rl->getModule( $name );
            if ( !$module ) {
                continue;
            }
 
            $group = $module->getGroup();
            $context = $this->getContext( $group, ResourceLoaderModule::TYPE_COMBINED );
            $shouldEmbed = $module->shouldEmbedModule( $this->context );
 
            if ( ( $group === 'user' || $shouldEmbed ) && $module->isKnownEmpty( $context ) ) {
                // This is a user-specific or embedded module, which means its output
                // can be specific to the current page or user. As such, we can optimise
                // the way we load it based on the current version of the module.
                // Avoid needless embed for empty module, preset ready state.
                $data['states'][$name] = 'ready';
            } elseif ( $group === 'user' || $shouldEmbed ) {
                // - For group=user: We need to provide a pre-generated load.php
                //   url to the client that has the 'user' and 'version' parameters
                //   filled in. Without this, the client would wrongly use the static
                //   version hash, per T64602.
                // - For shouldEmbed=true:  Embed via mw.loader.implement, per T36907.
                $data['embed']['general'][] = $name;
                // Avoid duplicate request from mw.loader
                $data['states'][$name] = 'loading';
            } else {
                // Load via mw.loader.load()
                $data['general'][] = $name;
            }
        }
 
        foreach ( $this->moduleStyles as $name ) {
            $module = $rl->getModule( $name );
            if ( !$module ) {
                continue;
            }
 
            if ( $module->getType() !== ResourceLoaderModule::LOAD_STYLES ) {
                $logger = $rl->getLogger();
                $logger->error( 'Unexpected general module "{module}" in styles queue.', [
                    'module' => $name,
                ] );
                continue;
            }
 
            // Stylesheet doesn't trigger mw.loader callback.
            // Set "ready" state to allow script modules to depend on this module  (T87871).
            // And to avoid duplicate requests at run-time from mw.loader.
            $data['states'][$name] = 'ready';
 
            $group = $module->getGroup();
            $context = $this->getContext( $group, ResourceLoaderModule::TYPE_STYLES );
            if ( $module->shouldEmbedModule( $this->context ) ) {
                // Avoid needless embed for private embeds we know are empty.
                // (Set "ready" state directly instead, which we do a few lines above.)
                if ( !$module->isKnownEmpty( $context ) ) {
                    // Embed via <style> element
                    $data['embed']['styles'][] = $name;
                }
            // For other style modules, always request them, regardless of whether they are
            // currently known to be empty. Because:
            // 1. Those modules are requested in batch, so there is no extra request overhead
            //    or extra HTML element to be avoided.
            // 2. Checking isKnownEmpty for those can be expensive and slow down page view
            //    generation (T230260).
            // 3. We don't want cached HTML to vary on the current state of a module.
            //    If the module becomes non-empty a few minutes later, it should start working
            //    on cached HTML without requiring a purge.
            //
            // But, user-specific modules:
            // * ... are used on page views not publicly cached.
            // * ... are in their own group and thus a require a request we can avoid
            // * ... have known-empty status preloaded by ResourceLoader.
            } elseif ( $group !== 'user' || !$module->isKnownEmpty( $context ) ) {
                // Load from load.php?only=styles via <link rel=stylesheet>
                $data['styles'][] = $name;
            }
            $deprecation = $module->getDeprecationInformation( $context );
            if ( $deprecation ) {
                $data['styleDeprecations'][] = $deprecation;
            }
        }
 
        return $data;
    }
 
    public function getDocumentAttributes() {
        return [ 'class' => 'client-nojs' ];
    }
 
    public function getHeadHtml( $nojsClass = null ) {
        $nonce = $this->options['nonce'];
        $data = $this->getData();
        $chunks = [];
 
        // Change "client-nojs" class to client-js. This allows easy toggling of UI components.
        // This must happen synchronously on every page view to avoid flashes of wrong content.
        // See also startup/startup.js.
        $nojsClass = $nojsClass ?? $this->getDocumentAttributes()['class'];
        $jsClass = preg_replace( '/(^|\s)client-nojs(\s|$)/', '$1client-js$2', $nojsClass );
        $jsClassJson = $this->context->encodeJson( $jsClass );
        $script = <<<JAVASCRIPT
document.documentElement.className = {$jsClassJson};
JAVASCRIPT;
 
        // Inline script: Declare mw.config variables for this page.
        if ( $this->config ) {
            $confJson = $this->context->encodeJson( $this->config );
            $script .= <<<JAVASCRIPT
RLCONF = {$confJson};
JAVASCRIPT;
        }
 
        // Inline script: Declare initial module states for this page.
        $states = array_merge( $this->exemptStates, $data['states'] );
        if ( $states ) {
            $stateJson = $this->context->encodeJson( $states );
            $script .= <<<JAVASCRIPT
RLSTATE = {$stateJson};
JAVASCRIPT;
        }
 
        // Inline script: Declare general modules to load on this page.
        if ( $data['general'] ) {
            $pageModulesJson = $this->context->encodeJson( $data['general'] );
            $script .= <<<JAVASCRIPT
RLPAGEMODULES = {$pageModulesJson};
JAVASCRIPT;
        }
 
        if ( !$this->context->getDebug() ) {
            $script = ResourceLoader::filter( 'minify-js', $script, [ 'cache' => false ] );
        }
 
        $chunks[] = Html::inlineScript( $script, $nonce );
 
        // Inline RLQ: Embedded modules
        if ( $data['embed']['general'] ) {
            $chunks[] = $this->getLoad(
                $data['embed']['general'],
                ResourceLoaderModule::TYPE_COMBINED,
                $nonce
            );
        }
 
        // External stylesheets (only=styles)
        if ( $data['styles'] ) {
            $chunks[] = $this->getLoad(
                $data['styles'],
                ResourceLoaderModule::TYPE_STYLES,
                $nonce
            );
        }
 
        // Inline stylesheets (embedded only=styles)
        if ( $data['embed']['styles'] ) {
            $chunks[] = $this->getLoad(
                $data['embed']['styles'],
                ResourceLoaderModule::TYPE_STYLES,
                $nonce
            );
        }
 
        // Async scripts. Once the startup is loaded, inline RLQ scripts will run.
        // Pass-through a custom 'target' from OutputPage (T143066).
        $startupQuery = [ 'raw' => '1' ];
        foreach ( [ 'target', 'safemode' ] as $param ) {
            if ( $this->options[$param] !== null ) {
                $startupQuery[$param] = (string)$this->options[$param];
            }
        }
        $chunks[] = $this->getLoad(
            'startup',
            ResourceLoaderModule::TYPE_SCRIPTS,
            $nonce,
            $startupQuery
        );
 
        return WrappedString::join( "\n", $chunks );
    }
 
    public function getBodyHtml() {
        $data = $this->getData();
        $chunks = [];
 
        // Deprecations for only=styles modules
        if ( $data['styleDeprecations'] ) {
            $chunks[] = ResourceLoader::makeInlineScript(
                implode( '', $data['styleDeprecations'] ),
                $this->options['nonce']
            );
        }
 
        return WrappedString::join( "\n", $chunks );
    }
 
    private function getContext( $group, $type ) {
        return self::makeContext( $this->context, $group, $type );
    }
 
    private function getLoad( $modules, $only, $nonce, array $extraQuery = [] ) {
        return self::makeLoad( $this->context, (array)$modules, $only, $extraQuery, $nonce );
    }
 
    private static function makeContext( ResourceLoaderContext $mainContext, $group, $type,
        array $extraQuery = []
    ) {
        // Create new ResourceLoaderContext so that $extraQuery is supported (eg. for 'sync=1').
        $req = new FauxRequest( array_merge( $mainContext->getRequest()->getValues(), $extraQuery ) );
        // Set 'only' if not combined
        $req->setVal( 'only', $type === ResourceLoaderModule::TYPE_COMBINED ? null : $type );
        // Remove user parameter in most cases
        if ( $group !== 'user' && $group !== 'private' ) {
            $req->setVal( 'user', null );
        }
        $context = new ResourceLoaderContext( $mainContext->getResourceLoader(), $req );
        // Allow caller to setVersion() and setModules()
        $ret = new DerivativeResourceLoaderContext( $context );
        $ret->setContentOverrideCallback( $mainContext->getContentOverrideCallback() );
        return $ret;
    }
 
    public static function makeLoad( ResourceLoaderContext $mainContext, array $modules, $only,
        array $extraQuery = [], $nonce = null
    ) {
        $rl = $mainContext->getResourceLoader();
        $chunks = [];
 
        // Sort module names so requests are more uniform
        sort( $modules );
 
        if ( $mainContext->getDebug() && count( $modules ) > 1 ) {
            $chunks = [];
            // Recursively call us for every item
            foreach ( $modules as $name ) {
                $chunks[] = self::makeLoad( $mainContext, [ $name ], $only, $extraQuery, $nonce );
            }
            return new WrappedStringList( "\n", $chunks );
        }
 
        // Create keyed-by-source and then keyed-by-group list of module objects from modules list
        $sortedModules = [];
        foreach ( $modules as $name ) {
            $module = $rl->getModule( $name );
            if ( !$module ) {
                $rl->getLogger()->warning( 'Unknown module "{module}"', [ 'module' => $name ] );
                continue;
            }
            $sortedModules[$module->getSource()][$module->getGroup()][$name] = $module;
        }
 
        foreach ( $sortedModules as $source => $groups ) {
            foreach ( $groups as $group => $grpModules ) {
                $context = self::makeContext( $mainContext, $group, $only, $extraQuery );
 
                // Separate sets of linked and embedded modules while preserving order
                $moduleSets = [];
                $idx = -1;
                foreach ( $grpModules as $name => $module ) {
                    $shouldEmbed = $module->shouldEmbedModule( $context );
                    if ( !$moduleSets || $moduleSets[$idx][0] !== $shouldEmbed ) {
                        $moduleSets[++$idx] = [ $shouldEmbed, [] ];
                    }
                    $moduleSets[$idx][1][$name] = $module;
                }
 
                // Link/embed each set
                foreach ( $moduleSets as list( $embed, $moduleSet ) ) {
                    $moduleSetNames = array_keys( $moduleSet );
                    $context->setModules( $moduleSetNames );
                    if ( $embed ) {
                        // Decide whether to use style or script element
                        if ( $only == ResourceLoaderModule::TYPE_STYLES ) {
                            $chunks[] = Html::inlineStyle(
                                $rl->makeModuleResponse( $context, $moduleSet )
                            );
                        } else {
                            $chunks[] = ResourceLoader::makeInlineScript(
                                $rl->makeModuleResponse( $context, $moduleSet ),
                                $nonce
                            );
                        }
                    } else {
                        // Special handling for the user group; because users might change their stuff
                        // on-wiki like user pages, or user preferences; we need to find the highest
                        // timestamp of these user-changeable modules so we can ensure cache misses on change
                        // This should NOT be done for the site group (T29564) because anons get that too
                        // and we shouldn't be putting timestamps in CDN-cached HTML
                        if ( $group === 'user' ) {
                            $context->setVersion( $rl->makeVersionQuery( $context, $moduleSetNames ) );
                        }
 
                        // Must setModules() before createLoaderURL()
                        $url = $rl->createLoaderURL( $source, $context, $extraQuery );
 
                        // Decide whether to use 'style' or 'script' element
                        if ( $only === ResourceLoaderModule::TYPE_STYLES ) {
                            $chunk = Html::linkedStyle( $url );
                        } elseif ( $context->getRaw() ) {
                            // This request is asking for the module to be delivered standalone,
                            // (aka "raw") without communicating to any mw.loader client.
                            // Use cases:
                            // - startup (naturally because this is what will define mw.loader)
                            // - html5shiv (loads synchronously in old IE before the async startup module arrives)
                            // - QUnit (needed in SpecialJavaScriptTest before async startup)
                            $chunk = Html::element( 'script', [
                                // The 'sync' option is only supported in combination with 'raw'.
                                'async' => !isset( $extraQuery['sync'] ),
                                'src' => $url
                            ] );
                        } else {
                            $chunk = ResourceLoader::makeInlineScript(
                                'mw.loader.load(' . $mainContext->encodeJson( $url ) . ');',
                                $nonce
                            );
                        }
 
                        if ( $group == 'noscript' ) {
                            $chunks[] = Html::rawElement( 'noscript', [], $chunk );
                        } else {
                            $chunks[] = $chunk;
                        }
                    }
                }
            }
        }
 
        return new WrappedStringList( "\n", $chunks );
    }
}