wikimedia/mediawiki-core

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includes/ResourceLoader/Context.php

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<?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 Trevor Parscal
 * @author Roan Kattouw
 */

namespace MediaWiki\ResourceLoader;

use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MediaWikiServices;
use MediaWiki\Message\Message;
use MediaWiki\Page\PageReferenceValue;
use MediaWiki\Request\FauxRequest;
use MediaWiki\Request\WebRequest;
use MediaWiki\User\User;
use MediaWiki\User\UserIdentity;
use MediaWiki\User\UserRigorOptions;
use MessageLocalizer;
use MessageSpecifier;
use Psr\Log\LoggerInterface;

/**
 * Context object that contains information about the state of a specific
 * ResourceLoader web request. Passed around to Module methods.
 *
 * @ingroup ResourceLoader
 * @since 1.17
 */
class Context implements MessageLocalizer {
    public const DEFAULT_LANG = 'qqx';
    public const DEFAULT_SKIN = 'fallback';

    /** @internal For use in ResourceLoader classes. */
    public const DEBUG_OFF = 0;
    /** @internal For use in ResourceLoader classes. */
    public const DEBUG_LEGACY = 1;
    /** @internal For use in SpecialJavaScriptTest. */
    public const DEBUG_MAIN = 2;

    /** @var ResourceLoader */
    protected $resourceLoader;
    /** @var WebRequest */
    protected $request;
    /** @var LoggerInterface */
    protected $logger;

    // Module content vary
    /** @var string */
    protected $skin;
    /** @var string */
    protected $language;
    /** @var int */
    protected $debug;
    /** @var string|null */
    protected $user;

    // Request vary (in addition to cache vary)
    /** @var string[] */
    protected $modules;
    /** @var string|null */
    protected $only;
    /** @var string|null */
    protected $version;
    /** @var bool */
    protected $raw;
    /** @var bool */
    protected $sourcemap;
    /** @var string|null */
    protected $image;
    /** @var string|null */
    protected $variant;
    /** @var string|null */
    protected $format;

    /** @var string|null */
    protected $direction;
    /** @var string|null */
    protected $hash;
    /** @var User|null */
    protected $userObj;
    /** @var UserIdentity|null|false */
    protected $userIdentity = false;
    /** @var Image|false */
    protected $imageObj;

    /**
     * @param ResourceLoader $resourceLoader
     * @param WebRequest $request
     */
    public function __construct( ResourceLoader $resourceLoader, WebRequest $request ) {
        $this->resourceLoader = $resourceLoader;
        $this->request = $request;
        $this->logger = $resourceLoader->getLogger();

        // Optimisation: Use WebRequest::getRawVal() instead of getVal(). We don't
        // need the slow Language+UTF logic meant for user input here. (f303bb9360)

        // List of modules
        $modules = $request->getRawVal( 'modules' );
        $this->modules = $modules ? ResourceLoader::expandModuleNames( $modules ) : [];

        // Various parameters
        $this->user = $request->getRawVal( 'user' );
        $this->debug = self::debugFromString( $request->getRawVal( 'debug' ) );
        $this->only = $request->getRawVal( 'only' );
        $this->version = $request->getRawVal( 'version' );
        $this->raw = $request->getFuzzyBool( 'raw' );
        $this->sourcemap = $request->getFuzzyBool( 'sourcemap' );

        // Image requests
        $this->image = $request->getRawVal( 'image' );
        $this->variant = $request->getRawVal( 'variant' );
        $this->format = $request->getRawVal( 'format' );

        $this->skin = $request->getRawVal( 'skin' );
        $skinFactory = MediaWikiServices::getInstance()->getSkinFactory();
        $skinnames = $skinFactory->getInstalledSkins();

        if ( !$this->skin || !isset( $skinnames[$this->skin] ) ) {
            // The 'skin' parameter is required. (Not yet enforced.)
            // For requests without a known skin specified,
            // use MediaWiki's 'fallback' skin for skin-specific decisions.
            $this->skin = self::DEFAULT_SKIN;
        }
    }

    /**
     * @internal For use in ResourceLoader::inDebugMode
     * @param string|null $debug
     * @return int
     */
    public static function debugFromString( ?string $debug ): int {
        // The canonical way to enable debug mode is via debug=true
        // This continues to map to v1 until v2 is ready (T85805).
        if ( $debug === 'true' || $debug === '1' ) {
            $ret = self::DEBUG_LEGACY;
        } elseif ( $debug === '2' ) {
            $ret = self::DEBUG_MAIN;
        } else {
            $ret = self::DEBUG_OFF;
        }

        return $ret;
    }

    /**
     * Return a dummy Context object suitable for passing into
     * things that don't "really" need a context.
     *
     * Use cases:
     * - Unit tests (deprecated, create empty instance directly or use RLTestCase).
     *
     * @return Context
     */
    public static function newDummyContext(): Context {
        // This currently creates a non-empty instance of ResourceLoader (all modules registered),
        // but that's probably not needed. So once that moves into ServiceWiring, this'll
        // become more like the EmptyResourceLoader class we have in PHPUnit tests, which
        // is what this should've had originally. If this turns out to be untrue, change to:
        // `MediaWikiServices::getInstance()->getResourceLoader()` instead.
        return new self( new ResourceLoader(
            MediaWikiServices::getInstance()->getMainConfig(),
            LoggerFactory::getInstance( 'resourceloader' )
        ), new FauxRequest( [] ) );
    }

    public function getResourceLoader(): ResourceLoader {
        return $this->resourceLoader;
    }

    public function getRequest(): WebRequest {
        return $this->request;
    }

    /**
     * @deprecated since 1.34 Use Module::getLogger instead
     * inside module methods. Use ResourceLoader::getLogger elsewhere.
     * @since 1.27
     * @return LoggerInterface
     */
    public function getLogger() {
        return $this->logger;
    }

    public function getModules(): array {
        return $this->modules;
    }

    public function getLanguage(): string {
        if ( $this->language === null ) {
            // Must be a valid language code after this point (T64849)
            // Only support uselang values that follow built-in conventions (T102058)
            $lang = $this->getRequest()->getRawVal( 'lang', '' );
            '@phan-var string $lang'; // getRawVal does not return null here
            // Stricter version of RequestContext::sanitizeLangCode()
            $validBuiltinCode = MediaWikiServices::getInstance()->getLanguageNameUtils()
                ->isValidBuiltInCode( $lang );
            if ( !$validBuiltinCode ) {
                // The 'lang' parameter is required. (Not yet enforced.)
                // If omitted, localise with the dummy language code.
                $lang = self::DEFAULT_LANG;
            }
            $this->language = $lang;
        }
        return $this->language;
    }

    public function getDirection(): string {
        if ( $this->direction === null ) {
            $direction = $this->getRequest()->getRawVal( 'dir' );
            if ( $direction === 'ltr' || $direction === 'rtl' ) {
                $this->direction = $direction;
            } else {
                // Determine directionality based on user language (T8100)
                $this->direction = MediaWikiServices::getInstance()->getLanguageFactory()
                    ->getLanguage( $this->getLanguage() )->getDir();
            }
        }
        return $this->direction;
    }

    public function getSkin(): string {
        return $this->skin;
    }

    /**
     * @return string|null
     */
    public function getUser(): ?string {
        return $this->user;
    }

    /**
     * Get a Message object with context set.  See wfMessage for parameters.
     *
     * @since 1.27
     * @param string|string[]|MessageSpecifier $key Message key, or array of keys,
     *   or a MessageSpecifier.
     * @param mixed ...$params
     * @return Message
     */
    public function msg( $key, ...$params ): Message {
        return wfMessage( $key, ...$params )
            // Do not use MediaWiki user language from session. Use the provided one instead.
            ->inLanguage( $this->getLanguage() )
            // inLanguage() clears the interface flag, so we need re-enable it. (T291601)
            ->setInterfaceMessageFlag( true )
            // Use a dummy title because there is no real title for this endpoint, and the cache won't
            // vary on it anyways.
            ->page( PageReferenceValue::localReference( NS_SPECIAL, 'Badtitle/ResourceLoaderContext' ) );
    }

    /**
     * Get the possibly-cached UserIdentity object for the specified username
     *
     * This will be null on most requests,
     * except for load.php requests that have a 'user' parameter set.
     *
     * @since 1.38
     * @return UserIdentity|null
     */
    public function getUserIdentity(): ?UserIdentity {
        if ( $this->userIdentity === false ) {
            $username = $this->getUser();
            if ( $username === null ) {
                // Anonymous user
                $this->userIdentity = null;
            } else {
                // Use provided username if valid
                $this->userIdentity = MediaWikiServices::getInstance()
                    ->getUserFactory()
                    ->newFromName( $username, UserRigorOptions::RIGOR_VALID );
            }
        }
        return $this->userIdentity;
    }

    /**
     * Get the possibly-cached User object for the specified username
     *
     * @since 1.25
     * @return User
     */
    public function getUserObj(): User {
        if ( $this->userObj === null ) {
            $username = $this->getUser();
            $userFactory = MediaWikiServices::getInstance()->getUserFactory();
            if ( $username ) {
                // Use provided username if valid, fallback to anonymous user
                $this->userObj = $userFactory->newFromName( $username, UserRigorOptions::RIGOR_VALID );
            }
            // Anonymous user
            $this->userObj ??= $userFactory->newAnonymous();
        }

        return $this->userObj;
    }

    public function getDebug(): int {
        return $this->debug;
    }

    /**
     * @return string|null
     */
    public function getOnly(): ?string {
        return $this->only;
    }

    /**
     * @see Module::getVersionHash
     * @see ClientHtml::makeLoad
     * @return string|null
     */
    public function getVersion(): ?string {
        return $this->version;
    }

    public function getRaw(): bool {
        return $this->raw;
    }

    /**
     * @since 1.41
     * @return bool
     */
    public function isSourceMap(): bool {
        return $this->sourcemap;
    }

    /**
     * @return string|null
     */
    public function getImage(): ?string {
        return $this->image;
    }

    /**
     * @return string|null
     */
    public function getVariant(): ?string {
        return $this->variant;
    }

    /**
     * @return string|null
     */
    public function getFormat(): ?string {
        return $this->format;
    }

    /**
     * If this is a request for an image, get the Image object.
     *
     * @since 1.25
     * @return Image|false false if a valid object cannot be created
     */
    public function getImageObj() {
        if ( $this->imageObj === null ) {
            $this->imageObj = false;

            if ( !$this->image ) {
                return $this->imageObj;
            }

            $modules = $this->getModules();
            if ( count( $modules ) !== 1 ) {
                return $this->imageObj;
            }

            $module = $this->getResourceLoader()->getModule( $modules[0] );
            if ( !$module || !$module instanceof ImageModule ) {
                return $this->imageObj;
            }

            $image = $module->getImage( $this->image, $this );
            if ( !$image ) {
                return $this->imageObj;
            }

            $this->imageObj = $image;
        }

        return $this->imageObj;
    }

    /**
     * Return the replaced-content mapping callback
     *
     * When editing a page that's used to generate the scripts or styles of a
     * WikiModule, a preview should use the to-be-saved version of
     * the page rather than the current version in the database. A context
     * supporting such previews should return a callback to return these
     * mappings here.
     *
     * @since 1.32
     * @return callable|null Signature is `Content|null func( Title $t )`
     */
    public function getContentOverrideCallback() {
        return null;
    }

    public function shouldIncludeScripts(): bool {
        return $this->getOnly() === null || $this->getOnly() === 'scripts';
    }

    public function shouldIncludeStyles(): bool {
        return $this->getOnly() === null || $this->getOnly() === 'styles';
    }

    public function shouldIncludeMessages(): bool {
        return $this->getOnly() === null;
    }

    /**
     * All factors that uniquely identify this request, except 'modules'.
     *
     * The list of modules is excluded here for legacy reasons as most callers already
     * split up handling of individual modules. Including it here would massively fragment
     * the cache and decrease its usefulness.
     *
     * E.g. Used by RequestFileCache to form a cache key for storing the response output.
     *
     * @return string
     */
    public function getHash(): string {
        if ( $this->hash === null ) {
            $this->hash = implode( '|', [
                // Module content vary
                $this->getLanguage(),
                $this->getSkin(),
                (string)$this->getDebug(),
                $this->getUser() ?? '',
                // Request vary
                $this->getOnly() ?? '',
                $this->getVersion() ?? '',
                (string)$this->getRaw(),
                $this->getImage() ?? '',
                $this->getVariant() ?? '',
                $this->getFormat() ?? '',
            ] );
        }
        return $this->hash;
    }

    /**
     * Get the request base parameters, omitting any defaults.
     *
     * @internal For use by StartUpModule only
     * @return string[]
     */
    public function getReqBase(): array {
        $reqBase = [];
        $lang = $this->getLanguage();
        if ( $lang !== self::DEFAULT_LANG ) {
            $reqBase['lang'] = $lang;
        }
        $skin = $this->getSkin();
        if ( $skin !== self::DEFAULT_SKIN ) {
            $reqBase['skin'] = $skin;
        }
        $debug = $this->getDebug();
        if ( $debug !== self::DEBUG_OFF ) {
            $reqBase['debug'] = strval( $debug );
        }
        return $reqBase;
    }

    /**
     * Wrapper around json_encode that avoids needless escapes,
     * and pretty-prints in debug mode.
     *
     * @since 1.34
     * @param mixed $data
     * @return string|false JSON string, false on error
     */
    public function encodeJson( $data ) {
        // Keep output as small as possible by disabling needless escape modes
        // that PHP uses by default.
        // However, while most module scripts are only served on HTTP responses
        // for JavaScript, some modules can also be embedded in the HTML as inline
        // scripts. This, and the fact that we sometimes need to export strings
        // containing user-generated content and labels that may genuinely contain
        // a sequences like "</script>", we need to encode either '/' or '<'.
        // By default PHP escapes '/'. Let's escape '<' instead which is less common
        // and allows URLs to mostly remain readable.
        $jsonFlags = JSON_UNESCAPED_SLASHES |
            JSON_UNESCAPED_UNICODE |
            JSON_PARTIAL_OUTPUT_ON_ERROR |
            JSON_HEX_TAG |
            JSON_HEX_AMP;
        if ( $this->getDebug() ) {
            $jsonFlags |= JSON_PRETTY_PRINT;
        }
        $json = json_encode( $data, $jsonFlags );
        if ( json_last_error() !== JSON_ERROR_NONE ) {
            trigger_error( __METHOD__ . ' partially failed: ' . json_last_error_msg(), E_USER_WARNING );
        }
        return $json;
    }
}