includes/ResourceLoader/ClientHtml.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
*/
namespace MediaWiki\ResourceLoader;
use MediaWiki\Html\Html;
use Wikimedia\WrappedString;
use Wikimedia\WrappedStringList;
/**
* Load and configure a ResourceLoader client on an HTML page.
*
* @ingroup ResourceLoader
* @since 1.28
*/
class ClientHtml {
/** @var Context */
private $context;
/** @var ResourceLoader */
private $resourceLoader;
/** @var array<string,string|null|false> */
private $options;
/** @var array<string,mixed> */
private $config = [];
/** @var string[] */
private $modules = [];
/** @var string[] */
private $moduleStyles = [];
/** @var array<string,string> */
private $exemptStates = [];
/** @var array */
private $data;
/**
* @param Context $context
* @param array $options [optional] Array of options
* - 'target': Parameter for modules=startup request, see StartUpModule.
* - 'safemode': Parameter for modules=startup request, see StartUpModule.
* - 'clientPrefEnabled': See Skin options.
* - 'clientPrefCookiePrefix': See $wgCookiePrefix.
*/
public function __construct( Context $context, array $options = [] ) {
$this->context = $context;
$this->resourceLoader = $context->getResourceLoader();
$this->options = $options + [
'target' => null,
'safemode' => null,
'clientPrefEnabled' => false,
'clientPrefCookiePrefix' => '',
];
}
/**
* Set mw.config variables.
*
* @param array $vars Array of key/value pairs
*/
public function setConfig( array $vars ): void {
foreach ( $vars as $key => $value ) {
$this->config[$key] = $value;
}
}
/**
* Ensure one or more modules are loaded.
*
* @param string[] $modules Array of module names
*/
public function setModules( array $modules ): void {
$this->modules = $modules;
}
/**
* Ensure the styles of one or more modules are loaded.
*
* @param string[] $modules Array of module names
*/
public function setModuleStyles( array $modules ): void {
$this->moduleStyles = $modules;
}
/**
* Set state of special modules that are handled by the caller manually.
*
* See OutputPage::buildExemptModules() for use cases.
*
* @param array<string,string> $states Module state keyed by module name
*/
public function setExemptStates( array $states ): void {
$this->exemptStates = $states;
}
private function getData(): array {
if ( $this->data ) {
// @codeCoverageIgnoreStart
return $this->data;
// @codeCoverageIgnoreEnd
}
$rl = $this->resourceLoader;
$data = [
'states' => [
// moduleName => state
],
'general' => [],
'styles' => [],
// Embedding for private modules
'embed' => [
'styles' => [],
'general' => [],
],
// Deprecation warnings for style-only modules
'styleDeprecations' => [],
];
foreach ( $this->modules as $name ) {
$module = $rl->getModule( $name );
if ( !$module ) {
continue;
}
$group = $module->getGroup();
$context = $this->getContext( $group, Module::TYPE_COMBINED );
$shouldEmbed = $module->shouldEmbedModule( $this->context );
if ( ( $group === Module::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 === Module::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.impl, 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() !== Module::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.
//
// Optimization: Exclude state for "noscript" modules. Since these are also excluded
// from the startup registry, no need to send their states (T291735).
$group = $module->getGroup();
if ( $group !== Module::GROUP_NOSCRIPT ) {
$data['states'][$name] = 'ready';
}
$context = $this->getContext( $group, Module::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 ( $group !== Module::GROUP_USER || !$module->isKnownEmpty( $context ) ) {
// Load from load.php?only=styles via <link rel=stylesheet>
$data['styles'][] = $name;
}
$deprecation = $module->getDeprecationWarning();
if ( $deprecation ) {
$data['styleDeprecations'][] = $deprecation;
}
}
return $data;
}
/**
* @return array<string,string> Attributes pairs for the HTML document element
*/
public function getDocumentAttributes() {
return [ 'class' => 'client-nojs' ];
}
/**
* Set relevant classes on document.documentElement
*
* @param string|null $nojsClass Class name that Skin will set on HTML document
* @return string
*/
private function getDocumentClassNameScript( $nojsClass ) {
// Change "client-nojs" to "client-js".
// This enables server rendering of UI components, even for those that should be hidden
// in Grade C where JavaScript is unsupported, whilst avoiding a flash of wrong content.
//
// See also Skin:getHtmlElementAttributes() and startup/startup.js.
//
// Optimisation: Produce shorter and faster JS by only writing to DOM.
// This is possible because Skin informs RL about the final value of <html class>, and
// because RL already controls the first element in HTML <head> for performance reasons.
// - Avoid reading HTMLElement.className
// - Avoid executing JS regexes in the common case, by doing the string replace in PHP.
$nojsClass ??= $this->getDocumentAttributes()['class'];
$jsClass = preg_replace( '/(^|\s)client-nojs(\s|$)/', '$1client-js$2', $nojsClass );
$jsClassJson = $this->context->encodeJson( $jsClass );
// Apply client preferences stored by mw.user.clientPrefs as "class1,class2", where each
// item is an <html> class following the pattern "<key>-clientpref-<value>" (T339268)
if ( $this->options['clientPrefEnabled'] ) {
$cookiePrefix = $this->options['clientPrefCookiePrefix'];
$script = strtr(
file_get_contents( MW_INSTALL_PATH . '/resources/src/startup/clientprefs.js' ),
[
'$VARS.jsClass' => $jsClassJson,
'__COOKIE_PREFIX__' => $cookiePrefix,
]
);
} else {
$script = "document.documentElement.className = {$jsClassJson};";
}
return $script;
}
/**
* The order of elements in the head is as follows:
* - Inline scripts.
* - Stylesheets.
* - Async external script-src.
*
* Reasons:
* - Script execution may be blocked on preceding stylesheets.
* - Async scripts are not blocked on stylesheets.
* - Inline scripts can't be asynchronous.
* - For styles, earlier is better.
*
* @param string|null $nojsClass Class name that caller uses on HTML document element
* @return string|WrappedStringList HTML
*/
public function getHeadHtml( $nojsClass = null ) {
$script = $this->getDocumentClassNameScript( $nojsClass );
// Inline script: Declare mw.config variables for this page.
if ( $this->config ) {
$confJson = $this->context->encodeJson( $this->config );
$script .= "
RLCONF = {$confJson};
";
}
$data = $this->getData();
// Inline script: Declare initial module states for this page.
$states = array_merge( $this->exemptStates, $data['states'] );
if ( $states ) {
$stateJson = $this->context->encodeJson( $states );
$script .= "
RLSTATE = {$stateJson};
";
}
// Inline script: Declare general modules to load on this page.
if ( $data['general'] ) {
$pageModulesJson = $this->context->encodeJson( $data['general'] );
$script .= "
RLPAGEMODULES = {$pageModulesJson};
";
}
if ( !$this->context->getDebug() ) {
$script = ResourceLoader::filter( 'minify-js', $script, [ 'cache' => false ] );
}
$chunks = [];
$chunks[] = Html::inlineScript( $script );
// Inline RLQ: Embedded modules
if ( $data['embed']['general'] ) {
$chunks[] = $this->getLoad(
$data['embed']['general'],
Module::TYPE_COMBINED
);
}
// External stylesheets (only=styles)
if ( $data['styles'] ) {
$chunks[] = $this->getLoad(
$data['styles'],
Module::TYPE_STYLES
);
}
// Inline stylesheets (embedded only=styles)
if ( $data['embed']['styles'] ) {
$chunks[] = $this->getLoad(
$data['embed']['styles'],
Module::TYPE_STYLES
);
}
// 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',
Module::TYPE_SCRIPTS,
$startupQuery
);
return WrappedString::join( "\n", $chunks );
}
/**
* @return string|WrappedStringList HTML
*/
public function getBodyHtml() {
$data = $this->getData();
$chunks = [];
// Deprecations for only=styles modules
if ( $data['styleDeprecations'] ) {
$calls = '';
foreach ( $data['styleDeprecations'] as $warning ) {
$calls .= Html::encodeJsCall( 'mw.log.warn', [ $warning ] );
}
$chunks[] = ResourceLoader::makeInlineScript( $calls );
}
return WrappedString::join( "\n", $chunks );
}
private function getContext( $group, $type ): Context {
return self::makeContext( $this->context, $group, $type );
}
private function getLoad( $modules, $only, array $extraQuery = [] ) {
return self::makeLoad( $this->context, (array)$modules, $only, $extraQuery );
}
private static function makeContext( Context $mainContext, $group, $type,
array $extraQuery = []
): DerivativeContext {
// Allow caller to setVersion() and setModules()
$ret = new DerivativeContext( $mainContext );
// Set 'only' if not combined
$ret->setOnly( $type === Module::TYPE_COMBINED ? null : $type );
// Remove user parameter in most cases
if ( $group !== Module::GROUP_USER && $group !== Module::GROUP_PRIVATE ) {
$ret->setUser( null );
}
if ( isset( $extraQuery['raw'] ) ) {
$ret->setRaw( true );
}
return $ret;
}
/**
* Explicitly load or embed modules on a page.
*
* @param Context $mainContext
* @param string[] $modules One or more module names
* @param string $only Module TYPE_ class constant
* @param array $extraQuery [optional] Array with extra query parameters for the request
* @return string|WrappedStringList HTML
*/
public static function makeLoad( Context $mainContext, array $modules, $only,
array $extraQuery = []
) {
$rl = $mainContext->getResourceLoader();
$chunks = [];
// Sort module names so requests are more uniform
sort( $modules );
if ( $mainContext->getDebug() && count( $modules ) > 1 ) {
// Recursively call us for every item
foreach ( $modules as $name ) {
$chunks[] = self::makeLoad( $mainContext, [ $name ], $only, $extraQuery );
}
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 [ $embed, $moduleSet ] ) {
$moduleSetNames = array_keys( $moduleSet );
$context->setModules( $moduleSetNames );
if ( $embed ) {
$response = $rl->makeModuleResponse( $context, $moduleSet );
// Decide whether to use style or script element
if ( $only == Module::TYPE_STYLES ) {
$chunks[] = Html::inlineStyle( $response );
} else {
$chunks[] = ResourceLoader::makeInlineScript( $response );
}
} else {
// Not embedded
// 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 === Module::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 === Module::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.
// For:
// - startup (naturally because this is what will define mw.loader)
$chunk = Html::element( 'script', [
'async' => true,
'src' => $url,
] );
} else {
$chunk = ResourceLoader::makeInlineScript(
'mw.loader.load(' . $mainContext->encodeJson( $url ) . ');'
);
}
if ( $group == Module::GROUP_NOSCRIPT ) {
$chunks[] = Html::rawElement( 'noscript', [], $chunk );
} else {
$chunks[] = $chunk;
}
}
}
}
}
return new WrappedStringList( "\n", $chunks );
}
}