includes/OutputPage.php

   1 <?php
   2 /**
   3  * Preparation for the final page rendering.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use MediaWiki\Linker\LinkTarget;
  24 use MediaWiki\Logger\LoggerFactory;
  25 use MediaWiki\MediaWikiServices;
  26 use MediaWiki\Session\SessionManager;
  27 use Wikimedia\RelPath;
  28 use Wikimedia\WrappedString;
  29 use Wikimedia\WrappedStringList;
  30
  31 /**
  32  * This class should be covered by a general architecture document which does
  33  * not exist as of January 2011.  This is one of the Core classes and should
  34  * be read at least once by any new developers.
  35  *
  36  * This class is used to prepare the final rendering. A skin is then
  37  * applied to the output parameters (links, javascript, html, categories ...).
  38  *
  39  * @todo FIXME: Another class handles sending the whole page to the client.
  40  *
  41  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  42  * in November 2010.
  43  *
  44  * @todo document
  45  */
  46 class OutputPage extends ContextSource {
  47         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  48         protected $mMetatags = [];
  49
  50         /** @var array */
  51         protected $mLinktags = [];
  52
  53         /** @var bool */
  54         protected $mCanonicalUrl = false;
  55
  56         /**
  57          * @var string Should be private - has getter and setter. Contains
  58          *   the HTML title */
  59         public $mPagetitle = '';
  60
  61         /**
  62          * @var string Contains all of the "<body>" content. Should be private we
  63          *   got set/get accessors and the append() method.
  64          */
  65         public $mBodytext = '';
  66
  67         /** @var string Stores contents of "<title>" tag */
  68         private $mHTMLtitle = '';
  69
  70         /**
  71          * @var bool Is the displayed content related to the source of the
  72          *   corresponding wiki article.
  73          */
  74         private $mIsarticle = false;
  75
  76         /** @var bool Stores "article flag" toggle. */
  77         private $mIsArticleRelated = true;
  78
  79         /**
  80          * @var bool We have to set isPrintable(). Some pages should
  81          * never be printed (ex: redirections).
  82          */
  83         private $mPrintable = false;
  84
  85         /**
  86          * @var array Contains the page subtitle. Special pages usually have some
  87          *   links here. Don't confuse with site subtitle added by skins.
  88          */
  89         private $mSubtitle = [];
  90
  91         /** @var string */
  92         public $mRedirect = '';
  93
  94         /** @var int */
  95         protected $mStatusCode;
  96
  97         /**
  98          * @var string Used for sending cache control.
  99          *   The whole caching system should probably be moved into its own class.
 100          */
 101         protected $mLastModified = '';
 102
 103         /** @var array */
 104         protected $mCategoryLinks = [];
 105
 106         /** @var array */
 107         protected $mCategories = [
 108                 'hidden' => [],
 109                 'normal' => [],
 110         ];
 111
 112         /** @var array */
 113         protected $mIndicators = [];
 114
 115         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 116         private $mLanguageLinks = [];
 117
 118         /**
 119          * Used for JavaScript (predates ResourceLoader)
 120          * @todo We should split JS / CSS.
 121          * mScripts content is inserted as is in "<head>" by Skin. This might
 122          * contain either a link to a stylesheet or inline CSS.
 123          */
 124         private $mScripts = '';
 125
 126         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 127         protected $mInlineStyles = '';
 128
 129         /**
 130          * @var string Used by skin template.
 131          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 132          */
 133         public $mPageLinkTitle = '';
 134
 135         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 136         protected $mHeadItems = [];
 137
 138         /** @var array Additional <body> classes; there are also <body> classes from other sources */
 139         protected $mAdditionalBodyClasses = [];
 140
 141         /** @var array */
 142         protected $mModules = [];
 143
 144         /** @var array */
 145         protected $mModuleScripts = [];
 146
 147         /** @var array */
 148         protected $mModuleStyles = [];
 149
 150         /** @var ResourceLoader */
 151         protected $mResourceLoader;
 152
 153         /** @var ResourceLoaderClientHtml */
 154         private $rlClient;
 155
 156         /** @var ResourceLoaderContext */
 157         private $rlClientContext;
 158
 159         /** @var array */
 160         private $rlExemptStyleModules;
 161
 162         /** @var array */
 163         protected $mJsConfigVars = [];
 164
 165         /** @var array */
 166         protected $mTemplateIds = [];
 167
 168         /** @var array */
 169         protected $mImageTimeKeys = [];
 170
 171         /** @var string */
 172         public $mRedirectCode = '';
 173
 174         protected $mFeedLinksAppendQuery = null;
 175
 176         /** @var array
 177          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 178          * @see ResourceLoaderModule::$origin
 179          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 180          */
 181         protected $mAllowedModules = [
 182                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 183         ];
 184
 185         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 186         protected $mDoNothing = false;
 187
 188         // Parser related.
 189
 190         /** @var int */
 191         protected $mContainsNewMagic = 0;
 192
 193         /**
 194          * lazy initialised, use parserOptions()
 195          * @var ParserOptions
 196          */
 197         protected $mParserOptions = null;
 198
 199         /**
 200          * Handles the Atom / RSS links.
 201          * We probably only support Atom in 2011.
 202          * @see $wgAdvertisedFeedTypes
 203          */
 204         private $mFeedLinks = [];
 205
 206         // Gwicke work on squid caching? Roughly from 2003.
 207         protected $mEnableClientCache = true;
 208
 209         /** @var bool Flag if output should only contain the body of the article. */
 210         private $mArticleBodyOnly = false;
 211
 212         /** @var bool */
 213         protected $mNewSectionLink = false;
 214
 215         /** @var bool */
 216         protected $mHideNewSectionLink = false;
 217
 218         /**
 219          * @var bool Comes from the parser. This was probably made to load CSS/JS
 220          * only if we had "<gallery>". Used directly in CategoryPage.php.
 221          * Looks like ResourceLoader can replace this.
 222          */
 223         public $mNoGallery = false;
 224
 225         /** @var string */
 226         private $mPageTitleActionText = '';
 227
 228         /** @var int Cache stuff. Looks like mEnableClientCache */
 229         protected $mCdnMaxage = 0;
 230         /** @var int Upper limit on mCdnMaxage */
 231         protected $mCdnMaxageLimit = INF;
 232
 233         /**
 234          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 235          * be sent. This should be done for pages where edit actions are possible.
 236          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 237          */
 238         protected $mPreventClickjacking = true;
 239
 240         /** @var int To include the variable {{REVISIONID}} */
 241         private $mRevisionId = null;
 242
 243         /** @var string */
 244         private $mRevisionTimestamp = null;
 245
 246         /** @var array */
 247         protected $mFileVersion = null;
 248
 249         /**
 250          * @var array An array of stylesheet filenames (relative from skins path),
 251          * with options for CSS media, IE conditions, and RTL/LTR direction.
 252          * For internal use; add settings in the skin via $this->addStyle()
 253          *
 254          * Style again! This seems like a code duplication since we already have
 255          * mStyles. This is what makes Open Source amazing.
 256          */
 257         protected $styles = [];
 258
 259         private $mIndexPolicy = 'index';
 260         private $mFollowPolicy = 'follow';
 261         private $mVaryHeader = [
 262                 'Accept-Encoding' => [ 'match=gzip' ],
 263         ];
 264
 265         /**
 266          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 267          * of the redirect.
 268          *
 269          * @var Title
 270          */
 271         private $mRedirectedFrom = null;
 272
 273         /**
 274          * Additional key => value data
 275          */
 276         private $mProperties = [];
 277
 278         /**
 279          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 280          */
 281         private $mTarget = null;
 282
 283         /**
 284          * @var bool Whether parser output contains a table of contents
 285          */
 286         private $mEnableTOC = false;
 287
 288         /**
 289          * @var string|null The URL to send in a <link> element with rel=license
 290          */
 291         private $copyrightUrl;
 292
 293         /** @var array Profiling data */
 294         private $limitReportJSData = [];
 295
 296         /** @var array Map Title to Content */
 297         private $contentOverrides = [];
 298
 299         /** @var callable[] */
 300         private $contentOverrideCallbacks = [];
 301
 302         /**
 303          * Link: header contents
 304          */
 305         private $mLinkHeader = [];
 306
 307         /**
 308          * Constructor for OutputPage. This should not be called directly.
 309          * Instead a new RequestContext should be created and it will implicitly create
 310          * a OutputPage tied to that context.
 311          * @param IContextSource $context
 312          */
 313         function __construct( IContextSource $context ) {
 314                 $this->setContext( $context );
 315         }
 316
 317         /**
 318          * Redirect to $url rather than displaying the normal page
 319          *
 320          * @param string $url
 321          * @param string $responsecode HTTP status code
 322          */
 323         public function redirect( $url, $responsecode = '302' ) {
 324                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 325                 $this->mRedirect = str_replace( "\n", '', $url );
 326                 $this->mRedirectCode = $responsecode;
 327         }
 328
 329         /**
 330          * Get the URL to redirect to, or an empty string if not redirect URL set
 331          *
 332          * @return string
 333          */
 334         public function getRedirect() {
 335                 return $this->mRedirect;
 336         }
 337
 338         /**
 339          * Set the copyright URL to send with the output.
 340          * Empty string to omit, null to reset.
 341          *
 342          * @since 1.26
 343          *
 344          * @param string|null $url
 345          */
 346         public function setCopyrightUrl( $url ) {
 347                 $this->copyrightUrl = $url;
 348         }
 349
 350         /**
 351          * Set the HTTP status code to send with the output.
 352          *
 353          * @param int $statusCode
 354          */
 355         public function setStatusCode( $statusCode ) {
 356                 $this->mStatusCode = $statusCode;
 357         }
 358
 359         /**
 360          * Add a new "<meta>" tag
 361          * To add an http-equiv meta tag, precede the name with "http:"
 362          *
 363          * @param string $name Name of the meta tag
 364          * @param string $val Value of the meta tag
 365          */
 366         function addMeta( $name, $val ) {
 367                 array_push( $this->mMetatags, [ $name, $val ] );
 368         }
 369
 370         /**
 371          * Returns the current <meta> tags
 372          *
 373          * @since 1.25
 374          * @return array
 375          */
 376         public function getMetaTags() {
 377                 return $this->mMetatags;
 378         }
 379
 380         /**
 381          * Add a new \<link\> tag to the page header.
 382          *
 383          * Note: use setCanonicalUrl() for rel=canonical.
 384          *
 385          * @param array $linkarr Associative array of attributes.
 386          */
 387         function addLink( array $linkarr ) {
 388                 array_push( $this->mLinktags, $linkarr );
 389         }
 390
 391         /**
 392          * Returns the current <link> tags
 393          *
 394          * @since 1.25
 395          * @return array
 396          */
 397         public function getLinkTags() {
 398                 return $this->mLinktags;
 399         }
 400
 401         /**
 402          * Add a new \<link\> with "rel" attribute set to "meta"
 403          *
 404          * @param array $linkarr Associative array mapping attribute names to their
 405          *                 values, both keys and values will be escaped, and the
 406          *                 "rel" attribute will be automatically added
 407          */
 408         function addMetadataLink( array $linkarr ) {
 409                 $linkarr['rel'] = $this->getMetadataAttribute();
 410                 $this->addLink( $linkarr );
 411         }
 412
 413         /**
 414          * Set the URL to be used for the <link rel=canonical>. This should be used
 415          * in preference to addLink(), to avoid duplicate link tags.
 416          * @param string $url
 417          */
 418         function setCanonicalUrl( $url ) {
 419                 $this->mCanonicalUrl = $url;
 420         }
 421
 422         /**
 423          * Returns the URL to be used for the <link rel=canonical> if
 424          * one is set.
 425          *
 426          * @since 1.25
 427          * @return bool|string
 428          */
 429         public function getCanonicalUrl() {
 430                 return $this->mCanonicalUrl;
 431         }
 432
 433         /**
 434          * Get the value of the "rel" attribute for metadata links
 435          *
 436          * @return string
 437          */
 438         public function getMetadataAttribute() {
 439                 # note: buggy CC software only reads first "meta" link
 440                 static $haveMeta = false;
 441                 if ( $haveMeta ) {
 442                         return 'alternate meta';
 443                 } else {
 444                         $haveMeta = true;
 445                         return 'meta';
 446                 }
 447         }
 448
 449         /**
 450          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 451          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 452          * if possible.
 453          *
 454          * @param string $script Raw HTML
 455          */
 456         function addScript( $script ) {
 457                 $this->mScripts .= $script;
 458         }
 459
 460         /**
 461          * Add a JavaScript file out of skins/common, or a given relative path.
 462          * Internal use only. Use OutputPage::addModules() if possible.
 463          *
 464          * @param string $file Filename in skins/common or complete on-server path
 465          *              (/foo/bar.js)
 466          * @param string $version Style version of the file. Defaults to $wgStyleVersion
 467          */
 468         public function addScriptFile( $file, $version = null ) {
 469                 // See if $file parameter is an absolute URL or begins with a slash
 470                 if ( substr( $file, 0, 1 ) == '/' || preg_match( '#^[a-z]*://#i', $file ) ) {
 471                         $path = $file;
 472                 } else {
 473                         $path = $this->getConfig()->get( 'StylePath' ) . "/common/{$file}";
 474                 }
 475                 if ( is_null( $version ) ) {
 476                         $version = $this->getConfig()->get( 'StyleVersion' );
 477                 }
 478                 $this->addScript( Html::linkedScript( wfAppendQuery( $path, $version ) ) );
 479         }
 480
 481         /**
 482          * Add a self-contained script tag with the given contents
 483          * Internal use only. Use OutputPage::addModules() if possible.
 484          *
 485          * @param string $script JavaScript text, no script tags
 486          */
 487         public function addInlineScript( $script ) {
 488                 $this->mScripts .= Html::inlineScript( $script );
 489         }
 490
 491         /**
 492          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 493          * which are no longer registered (eg a page is cached before an extension is disabled)
 494          * @param array $modules
 495          * @param string|null $position Unused
 496          * @param string $type
 497          * @return array
 498          */
 499         protected function filterModules( array $modules, $position = null,
 500                 $type = ResourceLoaderModule::TYPE_COMBINED
 501         ) {
 502                 $resourceLoader = $this->getResourceLoader();
 503                 $filteredModules = [];
 504                 foreach ( $modules as $val ) {
 505                         $module = $resourceLoader->getModule( $val );
 506                         if ( $module instanceof ResourceLoaderModule
 507                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 508                         ) {
 509                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 510                                         $this->warnModuleTargetFilter( $module->getName() );
 511                                         continue;
 512                                 }
 513                                 $filteredModules[] = $val;
 514                         }
 515                 }
 516                 return $filteredModules;
 517         }
 518
 519         private function warnModuleTargetFilter( $moduleName ) {
 520                 static $warnings = [];
 521                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 522                         return;
 523                 }
 524                 $warnings[$this->mTarget][$moduleName] = true;
 525                 $this->getResourceLoader()->getLogger()->debug(
 526                         'Module "{module}" not loadable on target "{target}".',
 527                         [
 528                                 'module' => $moduleName,
 529                                 'target' => $this->mTarget,
 530                         ]
 531                 );
 532         }
 533
 534         /**
 535          * Get the list of modules to include on this page
 536          *
 537          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 538          * @param string|null $position Unused
 539          * @param string $param
 540          * @param string $type
 541          * @return array Array of module names
 542          */
 543         public function getModules( $filter = false, $position = null, $param = 'mModules',
 544                 $type = ResourceLoaderModule::TYPE_COMBINED
 545         ) {
 546                 $modules = array_values( array_unique( $this->$param ) );
 547                 return $filter
 548                         ? $this->filterModules( $modules, null, $type )
 549                         : $modules;
 550         }
 551
 552         /**
 553          * Load one or more ResourceLoader modules on this page.
 554          *
 555          * @param string|array $modules Module name (string) or array of module names
 556          */
 557         public function addModules( $modules ) {
 558                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 559         }
 560
 561         /**
 562          * Get the list of script-only modules to load on this page.
 563          *
 564          * @param bool $filter
 565          * @param string|null $position Unused
 566          * @return array Array of module names
 567          */
 568         public function getModuleScripts( $filter = false, $position = null ) {
 569                 return $this->getModules( $filter, null, 'mModuleScripts',
 570                         ResourceLoaderModule::TYPE_SCRIPTS
 571                 );
 572         }
 573
 574         /**
 575          * Load the scripts of one or more ResourceLoader modules, on this page.
 576          *
 577          * This method exists purely to provide the legacy behaviour of loading
 578          * a module's scripts in the global scope, and without dependency resolution.
 579          * See <https://phabricator.wikimedia.org/T188689>.
 580          *
 581          * @deprecated since 1.31 Use addModules() instead.
 582          * @param string|array $modules Module name (string) or array of module names
 583          */
 584         public function addModuleScripts( $modules ) {
 585                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 586         }
 587
 588         /**
 589          * Get the list of style-only modules to load on this page.
 590          *
 591          * @param bool $filter
 592          * @param string|null $position Unused
 593          * @return array Array of module names
 594          */
 595         public function getModuleStyles( $filter = false, $position = null ) {
 596                 return $this->getModules( $filter, null, 'mModuleStyles',
 597                         ResourceLoaderModule::TYPE_STYLES
 598                 );
 599         }
 600
 601         /**
 602          * Load the styles of one or more ResourceLoader modules on this page.
 603          *
 604          * Module styles added through this function will be loaded as a stylesheet,
 605          * using a standard `<link rel=stylesheet>` HTML tag, rather than as a combined
 606          * Javascript and CSS package. Thus, they will even load when JavaScript is disabled.
 607          *
 608          * @param string|array $modules Module name (string) or array of module names
 609          */
 610         public function addModuleStyles( $modules ) {
 611                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 612         }
 613
 614         /**
 615          * @return null|string ResourceLoader target
 616          */
 617         public function getTarget() {
 618                 return $this->mTarget;
 619         }
 620
 621         /**
 622          * Sets ResourceLoader target for load.php links. If null, will be omitted
 623          *
 624          * @param string|null $target
 625          */
 626         public function setTarget( $target ) {
 627                 $this->mTarget = $target;
 628         }
 629
 630         /**
 631          * Add a mapping from a LinkTarget to a Content, for things like page preview.
 632          * @see self::addContentOverrideCallback()
 633          * @since 1.32
 634          * @param LinkTarget $target
 635          * @param Content $content
 636          */
 637         public function addContentOverride( LinkTarget $target, Content $content ) {
 638                 if ( !$this->contentOverrides ) {
 639                         // Register a callback for $this->contentOverrides on the first call
 640                         $this->addContentOverrideCallback( function ( LinkTarget $target ) {
 641                                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 642                                 return isset( $this->contentOverrides[$key] )
 643                                         ? $this->contentOverrides[$key]
 644                                         : null;
 645                         } );
 646                 }
 647
 648                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 649                 $this->contentOverrides[$key] = $content;
 650         }
 651
 652         /**
 653          * Add a callback for mapping from a Title to a Content object, for things
 654          * like page preview.
 655          * @see ResourceLoaderContext::getContentOverrideCallback()
 656          * @since 1.32
 657          * @param callable $callback
 658          */
 659         public function addContentOverrideCallback( callable $callback ) {
 660                 $this->contentOverrideCallbacks[] = $callback;
 661         }
 662
 663         /**
 664          * Get an array of head items
 665          *
 666          * @return array
 667          */
 668         function getHeadItemsArray() {
 669                 return $this->mHeadItems;
 670         }
 671
 672         /**
 673          * Add or replace a head item to the output
 674          *
 675          * Whenever possible, use more specific options like ResourceLoader modules,
 676          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 677          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 678          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 679          * This would be your very LAST fallback.
 680          *
 681          * @param string $name Item name
 682          * @param string $value Raw HTML
 683          */
 684         public function addHeadItem( $name, $value ) {
 685                 $this->mHeadItems[$name] = $value;
 686         }
 687
 688         /**
 689          * Add one or more head items to the output
 690          *
 691          * @since 1.28
 692          * @param string|string[] $values Raw HTML
 693          */
 694         public function addHeadItems( $values ) {
 695                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 696         }
 697
 698         /**
 699          * Check if the header item $name is already set
 700          *
 701          * @param string $name Item name
 702          * @return bool
 703          */
 704         public function hasHeadItem( $name ) {
 705                 return isset( $this->mHeadItems[$name] );
 706         }
 707
 708         /**
 709          * Add a class to the <body> element
 710          *
 711          * @since 1.30
 712          * @param string|string[] $classes One or more classes to add
 713          */
 714         public function addBodyClasses( $classes ) {
 715                 $this->mAdditionalBodyClasses = array_merge( $this->mAdditionalBodyClasses, (array)$classes );
 716         }
 717
 718         /**
 719          * Set whether the output should only contain the body of the article,
 720          * without any skin, sidebar, etc.
 721          * Used e.g. when calling with "action=render".
 722          *
 723          * @param bool $only Whether to output only the body of the article
 724          */
 725         public function setArticleBodyOnly( $only ) {
 726                 $this->mArticleBodyOnly = $only;
 727         }
 728
 729         /**
 730          * Return whether the output will contain only the body of the article
 731          *
 732          * @return bool
 733          */
 734         public function getArticleBodyOnly() {
 735                 return $this->mArticleBodyOnly;
 736         }
 737
 738         /**
 739          * Set an additional output property
 740          * @since 1.21
 741          *
 742          * @param string $name
 743          * @param mixed $value
 744          */
 745         public function setProperty( $name, $value ) {
 746                 $this->mProperties[$name] = $value;
 747         }
 748
 749         /**
 750          * Get an additional output property
 751          * @since 1.21
 752          *
 753          * @param string $name
 754          * @return mixed Property value or null if not found
 755          */
 756         public function getProperty( $name ) {
 757                 if ( isset( $this->mProperties[$name] ) ) {
 758                         return $this->mProperties[$name];
 759                 } else {
 760                         return null;
 761                 }
 762         }
 763
 764         /**
 765          * checkLastModified tells the client to use the client-cached page if
 766          * possible. If successful, the OutputPage is disabled so that
 767          * any future call to OutputPage->output() have no effect.
 768          *
 769          * Side effect: sets mLastModified for Last-Modified header
 770          *
 771          * @param string $timestamp
 772          *
 773          * @return bool True if cache-ok headers was sent.
 774          */
 775         public function checkLastModified( $timestamp ) {
 776                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 777                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 778                         return false;
 779                 }
 780                 $config = $this->getConfig();
 781                 if ( !$config->get( 'CachePages' ) ) {
 782                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 783                         return false;
 784                 }
 785
 786                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 787                 $modifiedTimes = [
 788                         'page' => $timestamp,
 789                         'user' => $this->getUser()->getTouched(),
 790                         'epoch' => $config->get( 'CacheEpoch' )
 791                 ];
 792                 if ( $config->get( 'UseSquid' ) ) {
 793                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, $this->getCdnCacheEpoch(
 794                                 time(),
 795                                 $config->get( 'SquidMaxage' )
 796                         ) );
 797                 }
 798                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 799
 800                 $maxModified = max( $modifiedTimes );
 801                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 802
 803                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 804                 if ( $clientHeader === false ) {
 805                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 806                         return false;
 807                 }
 808
 809                 # IE sends sizes after the date like this:
 810                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 811                 # this breaks strtotime().
 812                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 813
 814                 Wikimedia\suppressWarnings(); // E_STRICT system time bitching
 815                 $clientHeaderTime = strtotime( $clientHeader );
 816                 Wikimedia\restoreWarnings();
 817                 if ( !$clientHeaderTime ) {
 818                         wfDebug( __METHOD__
 819                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 820                         return false;
 821                 }
 822                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 823
 824                 # Make debug info
 825                 $info = '';
 826                 foreach ( $modifiedTimes as $name => $value ) {
 827                         if ( $info !== '' ) {
 828                                 $info .= ', ';
 829                         }
 830                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 831                 }
 832
 833                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 834                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 835                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 836                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 837                 if ( $clientHeaderTime < $maxModified ) {
 838                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 839                         return false;
 840                 }
 841
 842                 # Not modified
 843                 # Give a 304 Not Modified response code and disable body output
 844                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 845                 ini_set( 'zlib.output_compression', 0 );
 846                 $this->getRequest()->response()->statusHeader( 304 );
 847                 $this->sendCacheControl();
 848                 $this->disable();
 849
 850                 // Don't output a compressed blob when using ob_gzhandler;
 851                 // it's technically against HTTP spec and seems to confuse
 852                 // Firefox when the response gets split over two packets.
 853                 wfClearOutputBuffers();
 854
 855                 return true;
 856         }
 857
 858         /**
 859          * @param int $reqTime Time of request (eg. now)
 860          * @param int $maxAge Cache TTL in seconds
 861          * @return int Timestamp
 862          */
 863         private function getCdnCacheEpoch( $reqTime, $maxAge ) {
 864                 // Ensure Last-Modified is never more than (wgSquidMaxage) in the past,
 865                 // because even if the wiki page content hasn't changed since, static
 866                 // resources may have changed (skin HTML, interface messages, urls, etc.)
 867                 // and must roll-over in a timely manner (T46570)
 868                 return $reqTime - $maxAge;
 869         }
 870
 871         /**
 872          * Override the last modified timestamp
 873          *
 874          * @param string $timestamp New timestamp, in a format readable by
 875          *        wfTimestamp()
 876          */
 877         public function setLastModified( $timestamp ) {
 878                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 879         }
 880
 881         /**
 882          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 883          *
 884          * @param string $policy The literal string to output as the contents of
 885          *   the meta tag.  Will be parsed according to the spec and output in
 886          *   standardized form.
 887          * @return null
 888          */
 889         public function setRobotPolicy( $policy ) {
 890                 $policy = Article::formatRobotPolicy( $policy );
 891
 892                 if ( isset( $policy['index'] ) ) {
 893                         $this->setIndexPolicy( $policy['index'] );
 894                 }
 895                 if ( isset( $policy['follow'] ) ) {
 896                         $this->setFollowPolicy( $policy['follow'] );
 897                 }
 898         }
 899
 900         /**
 901          * Set the index policy for the page, but leave the follow policy un-
 902          * touched.
 903          *
 904          * @param string $policy Either 'index' or 'noindex'.
 905          * @return null
 906          */
 907         public function setIndexPolicy( $policy ) {
 908                 $policy = trim( $policy );
 909                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 910                         $this->mIndexPolicy = $policy;
 911                 }
 912         }
 913
 914         /**
 915          * Set the follow policy for the page, but leave the index policy un-
 916          * touched.
 917          *
 918          * @param string $policy Either 'follow' or 'nofollow'.
 919          * @return null
 920          */
 921         public function setFollowPolicy( $policy ) {
 922                 $policy = trim( $policy );
 923                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 924                         $this->mFollowPolicy = $policy;
 925                 }
 926         }
 927
 928         /**
 929          * Set the new value of the "action text", this will be added to the
 930          * "HTML title", separated from it with " - ".
 931          *
 932          * @param string $text New value of the "action text"
 933          */
 934         public function setPageTitleActionText( $text ) {
 935                 $this->mPageTitleActionText = $text;
 936         }
 937
 938         /**
 939          * Get the value of the "action text"
 940          *
 941          * @return string
 942          */
 943         public function getPageTitleActionText() {
 944                 return $this->mPageTitleActionText;
 945         }
 946
 947         /**
 948          * "HTML title" means the contents of "<title>".
 949          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 950          *
 951          * @param string|Message $name
 952          */
 953         public function setHTMLTitle( $name ) {
 954                 if ( $name instanceof Message ) {
 955                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 956                 } else {
 957                         $this->mHTMLtitle = $name;
 958                 }
 959         }
 960
 961         /**
 962          * Return the "HTML title", i.e. the content of the "<title>" tag.
 963          *
 964          * @return string
 965          */
 966         public function getHTMLTitle() {
 967                 return $this->mHTMLtitle;
 968         }
 969
 970         /**
 971          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 972          *
 973          * @param Title $t
 974          */
 975         public function setRedirectedFrom( $t ) {
 976                 $this->mRedirectedFrom = $t;
 977         }
 978
 979         /**
 980          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 981          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 982          * but not bad tags like \<script\>. This function automatically sets
 983          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 984          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 985          * good tags like \<i\> will be dropped entirely.
 986          *
 987          * @param string|Message $name
 988          */
 989         public function setPageTitle( $name ) {
 990                 if ( $name instanceof Message ) {
 991                         $name = $name->setContext( $this->getContext() )->text();
 992                 }
 993
 994                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 995                 # but leave "<i>foobar</i>" alone
 996                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 997                 $this->mPagetitle = $nameWithTags;
 998
 999                 # change "<i>foo&amp;bar</i>" to "foo&bar"
1000                 $this->setHTMLTitle(
1001                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
1002                                 ->inContentLanguage()
1003                 );
1004         }
1005
1006         /**
1007          * Return the "page title", i.e. the content of the \<h1\> tag.
1008          *
1009          * @return string
1010          */
1011         public function getPageTitle() {
1012                 return $this->mPagetitle;
1013         }
1014
1015         /**
1016          * Set the Title object to use
1017          *
1018          * @param Title $t
1019          */
1020         public function setTitle( Title $t ) {
1021                 $this->getContext()->setTitle( $t );
1022         }
1023
1024         /**
1025          * Replace the subtitle with $str
1026          *
1027          * @param string|Message $str New value of the subtitle. String should be safe HTML.
1028          */
1029         public function setSubtitle( $str ) {
1030                 $this->clearSubtitle();
1031                 $this->addSubtitle( $str );
1032         }
1033
1034         /**
1035          * Add $str to the subtitle
1036          *
1037          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
1038          */
1039         public function addSubtitle( $str ) {
1040                 if ( $str instanceof Message ) {
1041                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
1042                 } else {
1043                         $this->mSubtitle[] = $str;
1044                 }
1045         }
1046
1047         /**
1048          * Build message object for a subtitle containing a backlink to a page
1049          *
1050          * @param Title $title Title to link to
1051          * @param array $query Array of additional parameters to include in the link
1052          * @return Message
1053          * @since 1.25
1054          */
1055         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1056                 if ( $title->isRedirect() ) {
1057                         $query['redirect'] = 'no';
1058                 }
1059                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1060                 return wfMessage( 'backlinksubtitle' )
1061                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1062         }
1063
1064         /**
1065          * Add a subtitle containing a backlink to a page
1066          *
1067          * @param Title $title Title to link to
1068          * @param array $query Array of additional parameters to include in the link
1069          */
1070         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1071                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1072         }
1073
1074         /**
1075          * Clear the subtitles
1076          */
1077         public function clearSubtitle() {
1078                 $this->mSubtitle = [];
1079         }
1080
1081         /**
1082          * Get the subtitle
1083          *
1084          * @return string
1085          */
1086         public function getSubtitle() {
1087                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1088         }
1089
1090         /**
1091          * Set the page as printable, i.e. it'll be displayed with all
1092          * print styles included
1093          */
1094         public function setPrintable() {
1095                 $this->mPrintable = true;
1096         }
1097
1098         /**
1099          * Return whether the page is "printable"
1100          *
1101          * @return bool
1102          */
1103         public function isPrintable() {
1104                 return $this->mPrintable;
1105         }
1106
1107         /**
1108          * Disable output completely, i.e. calling output() will have no effect
1109          */
1110         public function disable() {
1111                 $this->mDoNothing = true;
1112         }
1113
1114         /**
1115          * Return whether the output will be completely disabled
1116          *
1117          * @return bool
1118          */
1119         public function isDisabled() {
1120                 return $this->mDoNothing;
1121         }
1122
1123         /**
1124          * Show an "add new section" link?
1125          *
1126          * @return bool
1127          */
1128         public function showNewSectionLink() {
1129                 return $this->mNewSectionLink;
1130         }
1131
1132         /**
1133          * Forcibly hide the new section link?
1134          *
1135          * @return bool
1136          */
1137         public function forceHideNewSectionLink() {
1138                 return $this->mHideNewSectionLink;
1139         }
1140
1141         /**
1142          * Add or remove feed links in the page header
1143          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1144          * for the new version
1145          * @see addFeedLink()
1146          *
1147          * @param bool $show True: add default feeds, false: remove all feeds
1148          */
1149         public function setSyndicated( $show = true ) {
1150                 if ( $show ) {
1151                         $this->setFeedAppendQuery( false );
1152                 } else {
1153                         $this->mFeedLinks = [];
1154                 }
1155         }
1156
1157         /**
1158          * Add default feeds to the page header
1159          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1160          * for the new version
1161          * @see addFeedLink()
1162          *
1163          * @param string $val Query to append to feed links or false to output
1164          *        default links
1165          */
1166         public function setFeedAppendQuery( $val ) {
1167                 $this->mFeedLinks = [];
1168
1169                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1170                         $query = "feed=$type";
1171                         if ( is_string( $val ) ) {
1172                                 $query .= '&' . $val;
1173                         }
1174                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1175                 }
1176         }
1177
1178         /**
1179          * Add a feed link to the page header
1180          *
1181          * @param string $format Feed type, should be a key of $wgFeedClasses
1182          * @param string $href URL
1183          */
1184         public function addFeedLink( $format, $href ) {
1185                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1186                         $this->mFeedLinks[$format] = $href;
1187                 }
1188         }
1189
1190         /**
1191          * Should we output feed links for this page?
1192          * @return bool
1193          */
1194         public function isSyndicated() {
1195                 return count( $this->mFeedLinks ) > 0;
1196         }
1197
1198         /**
1199          * Return URLs for each supported syndication format for this page.
1200          * @return array Associating format keys with URLs
1201          */
1202         public function getSyndicationLinks() {
1203                 return $this->mFeedLinks;
1204         }
1205
1206         /**
1207          * Will currently always return null
1208          *
1209          * @return null
1210          */
1211         public function getFeedAppendQuery() {
1212                 return $this->mFeedLinksAppendQuery;
1213         }
1214
1215         /**
1216          * Set whether the displayed content is related to the source of the
1217          * corresponding article on the wiki
1218          * Setting true will cause the change "article related" toggle to true
1219          *
1220          * @param bool $v
1221          */
1222         public function setArticleFlag( $v ) {
1223                 $this->mIsarticle = $v;
1224                 if ( $v ) {
1225                         $this->mIsArticleRelated = $v;
1226                 }
1227         }
1228
1229         /**
1230          * Return whether the content displayed page is related to the source of
1231          * the corresponding article on the wiki
1232          *
1233          * @return bool
1234          */
1235         public function isArticle() {
1236                 return $this->mIsarticle;
1237         }
1238
1239         /**
1240          * Set whether this page is related an article on the wiki
1241          * Setting false will cause the change of "article flag" toggle to false
1242          *
1243          * @param bool $v
1244          */
1245         public function setArticleRelated( $v ) {
1246                 $this->mIsArticleRelated = $v;
1247                 if ( !$v ) {
1248                         $this->mIsarticle = false;
1249                 }
1250         }
1251
1252         /**
1253          * Return whether this page is related an article on the wiki
1254          *
1255          * @return bool
1256          */
1257         public function isArticleRelated() {
1258                 return $this->mIsArticleRelated;
1259         }
1260
1261         /**
1262          * Add new language links
1263          *
1264          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1265          *                               (e.g. 'fr:Test page')
1266          */
1267         public function addLanguageLinks( array $newLinkArray ) {
1268                 $this->mLanguageLinks += $newLinkArray;
1269         }
1270
1271         /**
1272          * Reset the language links and add new language links
1273          *
1274          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1275          *                               (e.g. 'fr:Test page')
1276          */
1277         public function setLanguageLinks( array $newLinkArray ) {
1278                 $this->mLanguageLinks = $newLinkArray;
1279         }
1280
1281         /**
1282          * Get the list of language links
1283          *
1284          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1285          */
1286         public function getLanguageLinks() {
1287                 return $this->mLanguageLinks;
1288         }
1289
1290         /**
1291          * Add an array of categories, with names in the keys
1292          *
1293          * @param array $categories Mapping category name => sort key
1294          */
1295         public function addCategoryLinks( array $categories ) {
1296                 global $wgContLang;
1297
1298                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1299                         return;
1300                 }
1301
1302                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1303
1304                 # Set all the values to 'normal'.
1305                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1306
1307                 # Mark hidden categories
1308                 foreach ( $res as $row ) {
1309                         if ( isset( $row->pp_value ) ) {
1310                                 $categories[$row->page_title] = 'hidden';
1311                         }
1312                 }
1313
1314                 // Avoid PHP 7.1 warning of passing $this by reference
1315                 $outputPage = $this;
1316                 # Add the remaining categories to the skin
1317                 if ( Hooks::run(
1318                         'OutputPageMakeCategoryLinks',
1319                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1320                 ) {
1321                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1322                         foreach ( $categories as $category => $type ) {
1323                                 // array keys will cast numeric category names to ints, so cast back to string
1324                                 $category = (string)$category;
1325                                 $origcategory = $category;
1326                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1327                                 if ( !$title ) {
1328                                         continue;
1329                                 }
1330                                 $wgContLang->findVariantLink( $category, $title, true );
1331                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1332                                         continue;
1333                                 }
1334                                 $text = $wgContLang->convertHtml( $title->getText() );
1335                                 $this->mCategories[$type][] = $title->getText();
1336                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1337                         }
1338                 }
1339         }
1340
1341         /**
1342          * @param array $categories
1343          * @return bool|ResultWrapper
1344          */
1345         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1346                 # Add the links to a LinkBatch
1347                 $arr = [ NS_CATEGORY => $categories ];
1348                 $lb = new LinkBatch;
1349                 $lb->setArray( $arr );
1350
1351                 # Fetch existence plus the hiddencat property
1352                 $dbr = wfGetDB( DB_REPLICA );
1353                 $fields = array_merge(
1354                         LinkCache::getSelectFields(),
1355                         [ 'page_namespace', 'page_title', 'pp_value' ]
1356                 );
1357
1358                 $res = $dbr->select( [ 'page', 'page_props' ],
1359                         $fields,
1360                         $lb->constructSet( 'page', $dbr ),
1361                         __METHOD__,
1362                         [],
1363                         [ 'page_props' => [ 'LEFT JOIN', [
1364                                 'pp_propname' => 'hiddencat',
1365                                 'pp_page = page_id'
1366                         ] ] ]
1367                 );
1368
1369                 # Add the results to the link cache
1370                 $lb->addResultToCache( LinkCache::singleton(), $res );
1371
1372                 return $res;
1373         }
1374
1375         /**
1376          * Reset the category links (but not the category list) and add $categories
1377          *
1378          * @param array $categories Mapping category name => sort key
1379          */
1380         public function setCategoryLinks( array $categories ) {
1381                 $this->mCategoryLinks = [];
1382                 $this->addCategoryLinks( $categories );
1383         }
1384
1385         /**
1386          * Get the list of category links, in a 2-D array with the following format:
1387          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1388          * hidden categories) and $link a HTML fragment with a link to the category
1389          * page
1390          *
1391          * @return array
1392          */
1393         public function getCategoryLinks() {
1394                 return $this->mCategoryLinks;
1395         }
1396
1397         /**
1398          * Get the list of category names this page belongs to.
1399          *
1400          * @param string $type The type of categories which should be returned. Possible values:
1401          *  * all: all categories of all types
1402          *  * hidden: only the hidden categories
1403          *  * normal: all categories, except hidden categories
1404          * @return array Array of strings
1405          */
1406         public function getCategories( $type = 'all' ) {
1407                 if ( $type === 'all' ) {
1408                         $allCategories = [];
1409                         foreach ( $this->mCategories as $categories ) {
1410                                 $allCategories = array_merge( $allCategories, $categories );
1411                         }
1412                         return $allCategories;
1413                 }
1414                 if ( !isset( $this->mCategories[$type] ) ) {
1415                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1416                 }
1417                 return $this->mCategories[$type];
1418         }
1419
1420         /**
1421          * Add an array of indicators, with their identifiers as array
1422          * keys and HTML contents as values.
1423          *
1424          * In case of duplicate keys, existing values are overwritten.
1425          *
1426          * @param array $indicators
1427          * @since 1.25
1428          */
1429         public function setIndicators( array $indicators ) {
1430                 $this->mIndicators = $indicators + $this->mIndicators;
1431                 // Keep ordered by key
1432                 ksort( $this->mIndicators );
1433         }
1434
1435         /**
1436          * Get the indicators associated with this page.
1437          *
1438          * The array will be internally ordered by item keys.
1439          *
1440          * @return array Keys: identifiers, values: HTML contents
1441          * @since 1.25
1442          */
1443         public function getIndicators() {
1444                 return $this->mIndicators;
1445         }
1446
1447         /**
1448          * Adds help link with an icon via page indicators.
1449          * Link target can be overridden by a local message containing a wikilink:
1450          * the message key is: lowercase action or special page name + '-helppage'.
1451          * @param string $to Target MediaWiki.org page title or encoded URL.
1452          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1453          * @since 1.25
1454          */
1455         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1456                 $this->addModuleStyles( 'mediawiki.helplink' );
1457                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1458
1459                 if ( $overrideBaseUrl ) {
1460                         $helpUrl = $to;
1461                 } else {
1462                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1463                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1464                 }
1465
1466                 $link = Html::rawElement(
1467                         'a',
1468                         [
1469                                 'href' => $helpUrl,
1470                                 'target' => '_blank',
1471                                 'class' => 'mw-helplink',
1472                         ],
1473                         $text
1474                 );
1475
1476                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1477         }
1478
1479         /**
1480          * Do not allow scripts which can be modified by wiki users to load on this page;
1481          * only allow scripts bundled with, or generated by, the software.
1482          * Site-wide styles are controlled by a config setting, since they can be
1483          * used to create a custom skin/theme, but not user-specific ones.
1484          *
1485          * @todo this should be given a more accurate name
1486          */
1487         public function disallowUserJs() {
1488                 $this->reduceAllowedModules(
1489                         ResourceLoaderModule::TYPE_SCRIPTS,
1490                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1491                 );
1492
1493                 // Site-wide styles are controlled by a config setting, see T73621
1494                 // for background on why. User styles are never allowed.
1495                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1496                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1497                 } else {
1498                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1499                 }
1500                 $this->reduceAllowedModules(
1501                         ResourceLoaderModule::TYPE_STYLES,
1502                         $styleOrigin
1503                 );
1504         }
1505
1506         /**
1507          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1508          * @see ResourceLoaderModule::$origin
1509          * @param string $type ResourceLoaderModule TYPE_ constant
1510          * @return int ResourceLoaderModule ORIGIN_ class constant
1511          */
1512         public function getAllowedModules( $type ) {
1513                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1514                         return min( array_values( $this->mAllowedModules ) );
1515                 } else {
1516                         return isset( $this->mAllowedModules[$type] )
1517                                 ? $this->mAllowedModules[$type]
1518                                 : ResourceLoaderModule::ORIGIN_ALL;
1519                 }
1520         }
1521
1522         /**
1523          * Limit the highest level of CSS/JS untrustworthiness allowed.
1524          *
1525          * If passed the same or a higher level than the current level of untrustworthiness set, the
1526          * level will remain unchanged.
1527          *
1528          * @param string $type
1529          * @param int $level ResourceLoaderModule class constant
1530          */
1531         public function reduceAllowedModules( $type, $level ) {
1532                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1533         }
1534
1535         /**
1536          * Prepend $text to the body HTML
1537          *
1538          * @param string $text HTML
1539          */
1540         public function prependHTML( $text ) {
1541                 $this->mBodytext = $text . $this->mBodytext;
1542         }
1543
1544         /**
1545          * Append $text to the body HTML
1546          *
1547          * @param string $text HTML
1548          */
1549         public function addHTML( $text ) {
1550                 $this->mBodytext .= $text;
1551         }
1552
1553         /**
1554          * Shortcut for adding an Html::element via addHTML.
1555          *
1556          * @since 1.19
1557          *
1558          * @param string $element
1559          * @param array $attribs
1560          * @param string $contents
1561          */
1562         public function addElement( $element, array $attribs = [], $contents = '' ) {
1563                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1564         }
1565
1566         /**
1567          * Clear the body HTML
1568          */
1569         public function clearHTML() {
1570                 $this->mBodytext = '';
1571         }
1572
1573         /**
1574          * Get the body HTML
1575          *
1576          * @return string HTML
1577          */
1578         public function getHTML() {
1579                 return $this->mBodytext;
1580         }
1581
1582         /**
1583          * Get/set the ParserOptions object to use for wikitext parsing
1584          *
1585          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1586          *   current ParserOption object. This parameter is deprecated since 1.31.
1587          * @return ParserOptions
1588          */
1589         public function parserOptions( $options = null ) {
1590                 if ( $options !== null ) {
1591                         wfDeprecated( __METHOD__ . ' with non-null $options', '1.31' );
1592                 }
1593
1594                 if ( $options !== null && !empty( $options->isBogus ) ) {
1595                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1596                         // been changed somehow, and keep it if so.
1597                         $anonPO = ParserOptions::newFromAnon();
1598                         $anonPO->setAllowUnsafeRawHtml( false );
1599                         if ( !$options->matches( $anonPO ) ) {
1600                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1601                                 $options->isBogus = false;
1602                         }
1603                 }
1604
1605                 if ( !$this->mParserOptions ) {
1606                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1607                                 // $wgUser isn't unstubbable yet, so don't try to get a
1608                                 // ParserOptions for it. And don't cache this ParserOptions
1609                                 // either.
1610                                 $po = ParserOptions::newFromAnon();
1611                                 $po->setAllowUnsafeRawHtml( false );
1612                                 $po->isBogus = true;
1613                                 if ( $options !== null ) {
1614                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1615                                 }
1616                                 return $po;
1617                         }
1618
1619                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1620                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1621                 }
1622
1623                 if ( $options !== null && !empty( $options->isBogus ) ) {
1624                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1625                         // thing.
1626                         return wfSetVar( $this->mParserOptions, null, true );
1627                 } else {
1628                         return wfSetVar( $this->mParserOptions, $options );
1629                 }
1630         }
1631
1632         /**
1633          * Set the revision ID which will be seen by the wiki text parser
1634          * for things such as embedded {{REVISIONID}} variable use.
1635          *
1636          * @param int|null $revid An positive integer, or null
1637          * @return mixed Previous value
1638          */
1639         public function setRevisionId( $revid ) {
1640                 $val = is_null( $revid ) ? null : intval( $revid );
1641                 return wfSetVar( $this->mRevisionId, $val );
1642         }
1643
1644         /**
1645          * Get the displayed revision ID
1646          *
1647          * @return int
1648          */
1649         public function getRevisionId() {
1650                 return $this->mRevisionId;
1651         }
1652
1653         /**
1654          * Set the timestamp of the revision which will be displayed. This is used
1655          * to avoid a extra DB call in Skin::lastModified().
1656          *
1657          * @param string|null $timestamp
1658          * @return mixed Previous value
1659          */
1660         public function setRevisionTimestamp( $timestamp ) {
1661                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1662         }
1663
1664         /**
1665          * Get the timestamp of displayed revision.
1666          * This will be null if not filled by setRevisionTimestamp().
1667          *
1668          * @return string|null
1669          */
1670         public function getRevisionTimestamp() {
1671                 return $this->mRevisionTimestamp;
1672         }
1673
1674         /**
1675          * Set the displayed file version
1676          *
1677          * @param File|bool $file
1678          * @return mixed Previous value
1679          */
1680         public function setFileVersion( $file ) {
1681                 $val = null;
1682                 if ( $file instanceof File && $file->exists() ) {
1683                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1684                 }
1685                 return wfSetVar( $this->mFileVersion, $val, true );
1686         }
1687
1688         /**
1689          * Get the displayed file version
1690          *
1691          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1692          */
1693         public function getFileVersion() {
1694                 return $this->mFileVersion;
1695         }
1696
1697         /**
1698          * Get the templates used on this page
1699          *
1700          * @return array (namespace => dbKey => revId)
1701          * @since 1.18
1702          */
1703         public function getTemplateIds() {
1704                 return $this->mTemplateIds;
1705         }
1706
1707         /**
1708          * Get the files used on this page
1709          *
1710          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1711          * @since 1.18
1712          */
1713         public function getFileSearchOptions() {
1714                 return $this->mImageTimeKeys;
1715         }
1716
1717         /**
1718          * Convert wikitext to HTML and add it to the buffer
1719          * Default assumes that the current page title will be used.
1720          *
1721          * @param string $text
1722          * @param bool $linestart Is this the start of a line?
1723          * @param bool $interface Is this text in the user interface language?
1724          * @throws MWException
1725          */
1726         public function addWikiText( $text, $linestart = true, $interface = true ) {
1727                 $title = $this->getTitle(); // Work around E_STRICT
1728                 if ( !$title ) {
1729                         throw new MWException( 'Title is null' );
1730                 }
1731                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1732         }
1733
1734         /**
1735          * Add wikitext with a custom Title object
1736          *
1737          * @param string $text Wikitext
1738          * @param Title &$title
1739          * @param bool $linestart Is this the start of a line?
1740          */
1741         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1742                 $this->addWikiTextTitle( $text, $title, $linestart );
1743         }
1744
1745         /**
1746          * Add wikitext with a custom Title object and tidy enabled.
1747          *
1748          * @param string $text Wikitext
1749          * @param Title &$title
1750          * @param bool $linestart Is this the start of a line?
1751          */
1752         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1753                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1754         }
1755
1756         /**
1757          * Add wikitext with tidy enabled
1758          *
1759          * @param string $text Wikitext
1760          * @param bool $linestart Is this the start of a line?
1761          */
1762         public function addWikiTextTidy( $text, $linestart = true ) {
1763                 $title = $this->getTitle();
1764                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1765         }
1766
1767         /**
1768          * Add wikitext with a custom Title object
1769          *
1770          * @param string $text Wikitext
1771          * @param Title $title
1772          * @param bool $linestart Is this the start of a line?
1773          * @param bool $tidy Whether to use tidy
1774          * @param bool $interface Whether it is an interface message
1775          *   (for example disables conversion)
1776          */
1777         public function addWikiTextTitle( $text, Title $title, $linestart,
1778                 $tidy = false, $interface = false
1779         ) {
1780                 global $wgParser;
1781
1782                 $popts = $this->parserOptions();
1783                 $oldTidy = $popts->setTidy( $tidy );
1784                 $popts->setInterfaceMessage( (bool)$interface );
1785
1786                 $parserOutput = $wgParser->getFreshParser()->parse(
1787                         $text, $title, $popts,
1788                         $linestart, true, $this->mRevisionId
1789                 );
1790
1791                 $popts->setTidy( $oldTidy );
1792
1793                 $this->addParserOutput( $parserOutput, [
1794                         'enableSectionEditLinks' => false,
1795                 ] );
1796         }
1797
1798         /**
1799          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1800          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1801          * and so on.
1802          *
1803          * @since 1.24
1804          * @param ParserOutput $parserOutput
1805          */
1806         public function addParserOutputMetadata( $parserOutput ) {
1807                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1808                 $this->addCategoryLinks( $parserOutput->getCategories() );
1809                 $this->setIndicators( $parserOutput->getIndicators() );
1810                 $this->mNewSectionLink = $parserOutput->getNewSection();
1811                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1812
1813                 if ( !$parserOutput->isCacheable() ) {
1814                         $this->enableClientCache( false );
1815                 }
1816                 $this->mNoGallery = $parserOutput->getNoGallery();
1817                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1818                 $this->addModules( $parserOutput->getModules() );
1819                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1820                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1821                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1822                 $this->mPreventClickjacking = $this->mPreventClickjacking
1823                         || $parserOutput->preventClickjacking();
1824
1825                 // Template versioning...
1826                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1827                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1828                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1829                         } else {
1830                                 $this->mTemplateIds[$ns] = $dbks;
1831                         }
1832                 }
1833                 // File versioning...
1834                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1835                         $this->mImageTimeKeys[$dbk] = $data;
1836                 }
1837
1838                 // Hooks registered in the object
1839                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1840                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1841                         list( $hookName, $data ) = $hookInfo;
1842                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1843                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1844                         }
1845                 }
1846
1847                 // Enable OOUI if requested via ParserOutput
1848                 if ( $parserOutput->getEnableOOUI() ) {
1849                         $this->enableOOUI();
1850                 }
1851
1852                 // Include parser limit report
1853                 if ( !$this->limitReportJSData ) {
1854                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1855                 }
1856
1857                 // Link flags are ignored for now, but may in the future be
1858                 // used to mark individual language links.
1859                 $linkFlags = [];
1860                 // Avoid PHP 7.1 warning of passing $this by reference
1861                 $outputPage = $this;
1862                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1863                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1864
1865                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
1866                 // so that extensions may modify ParserOutput to toggle TOC.
1867                 // This cannot be moved to addParserOutputText because that is not
1868                 // called by EditPage for Preview.
1869                 if ( $parserOutput->getTOCHTML() ) {
1870                         $this->mEnableTOC = true;
1871                 }
1872         }
1873
1874         /**
1875          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1876          * ParserOutput object, without any other metadata.
1877          *
1878          * @since 1.24
1879          * @param ParserOutput $parserOutput
1880          * @param array $poOptions Options to ParserOutput::getText()
1881          */
1882         public function addParserOutputContent( $parserOutput, $poOptions = [] ) {
1883                 $this->addParserOutputText( $parserOutput, $poOptions );
1884
1885                 $this->addModules( $parserOutput->getModules() );
1886                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1887                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1888
1889                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1890         }
1891
1892         /**
1893          * Add the HTML associated with a ParserOutput object, without any metadata.
1894          *
1895          * @since 1.24
1896          * @param ParserOutput $parserOutput
1897          * @param array $poOptions Options to ParserOutput::getText()
1898          */
1899         public function addParserOutputText( $parserOutput, $poOptions = [] ) {
1900                 $text = $parserOutput->getText( $poOptions );
1901                 // Avoid PHP 7.1 warning of passing $this by reference
1902                 $outputPage = $this;
1903                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1904                 $this->addHTML( $text );
1905         }
1906
1907         /**
1908          * Add everything from a ParserOutput object.
1909          *
1910          * @param ParserOutput $parserOutput
1911          * @param array $poOptions Options to ParserOutput::getText()
1912          */
1913         function addParserOutput( $parserOutput, $poOptions = [] ) {
1914                 $this->addParserOutputMetadata( $parserOutput );
1915                 $this->addParserOutputText( $parserOutput, $poOptions );
1916         }
1917
1918         /**
1919          * Add the output of a QuickTemplate to the output buffer
1920          *
1921          * @param QuickTemplate &$template
1922          */
1923         public function addTemplate( &$template ) {
1924                 $this->addHTML( $template->getHTML() );
1925         }
1926
1927         /**
1928          * Parse wikitext and return the HTML.
1929          *
1930          * @param string $text
1931          * @param bool $linestart Is this the start of a line?
1932          * @param bool $interface Use interface language ($wgLang instead of
1933          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1934          *   This also disables LanguageConverter.
1935          * @param Language $language Target language object, will override $interface
1936          * @throws MWException
1937          * @return string HTML
1938          */
1939         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1940                 global $wgParser;
1941
1942                 if ( is_null( $this->getTitle() ) ) {
1943                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1944                 }
1945
1946                 $popts = $this->parserOptions();
1947                 if ( $interface ) {
1948                         $popts->setInterfaceMessage( true );
1949                 }
1950                 if ( $language !== null ) {
1951                         $oldLang = $popts->setTargetLanguage( $language );
1952                 }
1953
1954                 $parserOutput = $wgParser->getFreshParser()->parse(
1955                         $text, $this->getTitle(), $popts,
1956                         $linestart, true, $this->mRevisionId
1957                 );
1958
1959                 if ( $interface ) {
1960                         $popts->setInterfaceMessage( false );
1961                 }
1962                 if ( $language !== null ) {
1963                         $popts->setTargetLanguage( $oldLang );
1964                 }
1965
1966                 return $parserOutput->getText( [
1967                         'enableSectionEditLinks' => false,
1968                 ] );
1969         }
1970
1971         /**
1972          * Parse wikitext, strip paragraphs, and return the HTML.
1973          *
1974          * @param string $text
1975          * @param bool $linestart Is this the start of a line?
1976          * @param bool $interface Use interface language ($wgLang instead of
1977          *   $wgContLang) while parsing language sensitive magic
1978          *   words like GRAMMAR and PLURAL
1979          * @return string HTML
1980          */
1981         public function parseInline( $text, $linestart = true, $interface = false ) {
1982                 $parsed = $this->parse( $text, $linestart, $interface );
1983                 return Parser::stripOuterParagraph( $parsed );
1984         }
1985
1986         /**
1987          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1988          *
1989          * @param int $maxage Maximum cache time on the CDN, in seconds.
1990          */
1991         public function setCdnMaxage( $maxage ) {
1992                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1993         }
1994
1995         /**
1996          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1997          *
1998          * @param int $maxage Maximum cache time on the CDN, in seconds
1999          * @since 1.27
2000          */
2001         public function lowerCdnMaxage( $maxage ) {
2002                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
2003                 $this->setCdnMaxage( $this->mCdnMaxage );
2004         }
2005
2006         /**
2007          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
2008          *
2009          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
2010          * the TTL is higher the older the $mtime timestamp is. Essentially, the
2011          * TTL is 90% of the age of the object, subject to the min and max.
2012          *
2013          * @param string|int|float|bool|null $mtime Last-Modified timestamp
2014          * @param int $minTTL Mimimum TTL in seconds [default: 1 minute]
2015          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
2016          * @return int TTL in seconds
2017          * @since 1.28
2018          */
2019         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
2020                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
2021                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
2022
2023                 if ( $mtime === null || $mtime === false ) {
2024                         return $minTTL; // entity does not exist
2025                 }
2026
2027                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
2028                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
2029                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
2030
2031                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2032
2033                 return $adaptiveTTL;
2034         }
2035
2036         /**
2037          * Use enableClientCache(false) to force it to send nocache headers
2038          *
2039          * @param bool $state
2040          *
2041          * @return bool
2042          */
2043         public function enableClientCache( $state ) {
2044                 return wfSetVar( $this->mEnableClientCache, $state );
2045         }
2046
2047         /**
2048          * Get the list of cookies that will influence on the cache
2049          *
2050          * @return array
2051          */
2052         function getCacheVaryCookies() {
2053                 static $cookies;
2054                 if ( $cookies === null ) {
2055                         $config = $this->getConfig();
2056                         $cookies = array_merge(
2057                                 SessionManager::singleton()->getVaryCookies(),
2058                                 [
2059                                         'forceHTTPS',
2060                                 ],
2061                                 $config->get( 'CacheVaryCookies' )
2062                         );
2063                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2064                 }
2065                 return $cookies;
2066         }
2067
2068         /**
2069          * Check if the request has a cache-varying cookie header
2070          * If it does, it's very important that we don't allow public caching
2071          *
2072          * @return bool
2073          */
2074         function haveCacheVaryCookies() {
2075                 $request = $this->getRequest();
2076                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2077                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2078                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2079                                 return true;
2080                         }
2081                 }
2082                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2083                 return false;
2084         }
2085
2086         /**
2087          * Add an HTTP header that will influence on the cache
2088          *
2089          * @param string $header Header name
2090          * @param string[]|null $option Options for the Key header. See
2091          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2092          * for the list of valid options.
2093          */
2094         public function addVaryHeader( $header, array $option = null ) {
2095                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2096                         $this->mVaryHeader[$header] = [];
2097                 }
2098                 if ( !is_array( $option ) ) {
2099                         $option = [];
2100                 }
2101                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2102         }
2103
2104         /**
2105          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2106          * such as Accept-Encoding or Cookie
2107          *
2108          * @return string
2109          */
2110         public function getVaryHeader() {
2111                 // If we vary on cookies, let's make sure it's always included here too.
2112                 if ( $this->getCacheVaryCookies() ) {
2113                         $this->addVaryHeader( 'Cookie' );
2114                 }
2115
2116                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2117                         $this->addVaryHeader( $header, $options );
2118                 }
2119                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2120         }
2121
2122         /**
2123          * Add an HTTP Link: header
2124          *
2125          * @param string $header Header value
2126          */
2127         public function addLinkHeader( $header ) {
2128                 $this->mLinkHeader[] = $header;
2129         }
2130
2131         /**
2132          * Return a Link: header. Based on the values of $mLinkHeader.
2133          *
2134          * @return string
2135          */
2136         public function getLinkHeader() {
2137                 if ( !$this->mLinkHeader ) {
2138                         return false;
2139                 }
2140
2141                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2142         }
2143
2144         /**
2145          * Get a complete Key header
2146          *
2147          * @return string
2148          */
2149         public function getKeyHeader() {
2150                 $cvCookies = $this->getCacheVaryCookies();
2151
2152                 $cookiesOption = [];
2153                 foreach ( $cvCookies as $cookieName ) {
2154                         $cookiesOption[] = 'param=' . $cookieName;
2155                 }
2156                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2157
2158                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2159                         $this->addVaryHeader( $header, $options );
2160                 }
2161
2162                 $headers = [];
2163                 foreach ( $this->mVaryHeader as $header => $option ) {
2164                         $newheader = $header;
2165                         if ( is_array( $option ) && count( $option ) > 0 ) {
2166                                 $newheader .= ';' . implode( ';', $option );
2167                         }
2168                         $headers[] = $newheader;
2169                 }
2170                 $key = 'Key: ' . implode( ',', $headers );
2171
2172                 return $key;
2173         }
2174
2175         /**
2176          * T23672: Add Accept-Language to Vary and Key headers
2177          * if there's no 'variant' parameter existed in GET.
2178          *
2179          * For example:
2180          *   /w/index.php?title=Main_page should always be served; but
2181          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2182          */
2183         function addAcceptLanguage() {
2184                 $title = $this->getTitle();
2185                 if ( !$title instanceof Title ) {
2186                         return;
2187                 }
2188
2189                 $lang = $title->getPageLanguage();
2190                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2191                         $variants = $lang->getVariants();
2192                         $aloption = [];
2193                         foreach ( $variants as $variant ) {
2194                                 if ( $variant === $lang->getCode() ) {
2195                                         continue;
2196                                 } else {
2197                                         $aloption[] = 'substr=' . $variant;
2198
2199                                         // IE and some other browsers use BCP 47 standards in
2200                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2201                                         // We should handle these too.
2202                                         $variantBCP47 = LanguageCode::bcp47( $variant );
2203                                         if ( $variantBCP47 !== $variant ) {
2204                                                 $aloption[] = 'substr=' . $variantBCP47;
2205                                         }
2206                                 }
2207                         }
2208                         $this->addVaryHeader( 'Accept-Language', $aloption );
2209                 }
2210         }
2211
2212         /**
2213          * Set a flag which will cause an X-Frame-Options header appropriate for
2214          * edit pages to be sent. The header value is controlled by
2215          * $wgEditPageFrameOptions.
2216          *
2217          * This is the default for special pages. If you display a CSRF-protected
2218          * form on an ordinary view page, then you need to call this function.
2219          *
2220          * @param bool $enable
2221          */
2222         public function preventClickjacking( $enable = true ) {
2223                 $this->mPreventClickjacking = $enable;
2224         }
2225
2226         /**
2227          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2228          * This can be called from pages which do not contain any CSRF-protected
2229          * HTML form.
2230          */
2231         public function allowClickjacking() {
2232                 $this->mPreventClickjacking = false;
2233         }
2234
2235         /**
2236          * Get the prevent-clickjacking flag
2237          *
2238          * @since 1.24
2239          * @return bool
2240          */
2241         public function getPreventClickjacking() {
2242                 return $this->mPreventClickjacking;
2243         }
2244
2245         /**
2246          * Get the X-Frame-Options header value (without the name part), or false
2247          * if there isn't one. This is used by Skin to determine whether to enable
2248          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2249          *
2250          * @return string|false
2251          */
2252         public function getFrameOptions() {
2253                 $config = $this->getConfig();
2254                 if ( $config->get( 'BreakFrames' ) ) {
2255                         return 'DENY';
2256                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2257                         return $config->get( 'EditPageFrameOptions' );
2258                 }
2259                 return false;
2260         }
2261
2262         /**
2263          * Send cache control HTTP headers
2264          */
2265         public function sendCacheControl() {
2266                 $response = $this->getRequest()->response();
2267                 $config = $this->getConfig();
2268
2269                 $this->addVaryHeader( 'Cookie' );
2270                 $this->addAcceptLanguage();
2271
2272                 # don't serve compressed data to clients who can't handle it
2273                 # maintain different caches for logged-in users and non-logged in ones
2274                 $response->header( $this->getVaryHeader() );
2275
2276                 if ( $config->get( 'UseKeyHeader' ) ) {
2277                         $response->header( $this->getKeyHeader() );
2278                 }
2279
2280                 if ( $this->mEnableClientCache ) {
2281                         if (
2282                                 $config->get( 'UseSquid' ) &&
2283                                 !$response->hasCookies() &&
2284                                 !SessionManager::getGlobalSession()->isPersistent() &&
2285                                 !$this->isPrintable() &&
2286                                 $this->mCdnMaxage != 0 &&
2287                                 !$this->haveCacheVaryCookies()
2288                         ) {
2289                                 if ( $config->get( 'UseESI' ) ) {
2290                                         # We'll purge the proxy cache explicitly, but require end user agents
2291                                         # to revalidate against the proxy on each visit.
2292                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2293                                         wfDebug( __METHOD__ .
2294                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2295                                         # start with a shorter timeout for initial testing
2296                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2297                                         $response->header(
2298                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2299                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2300                                         );
2301                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2302                                 } else {
2303                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2304                                         # to revalidate against the proxy on each visit.
2305                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2306                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2307                                         wfDebug( __METHOD__ .
2308                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2309                                         # start with a shorter timeout for initial testing
2310                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2311                                         $response->header( "Cache-Control: " .
2312                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2313                                 }
2314                         } else {
2315                                 # We do want clients to cache if they can, but they *must* check for updates
2316                                 # on revisiting the page.
2317                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2318                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2319                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2320                         }
2321                         if ( $this->mLastModified ) {
2322                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2323                         }
2324                 } else {
2325                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2326
2327                         # In general, the absence of a last modified header should be enough to prevent
2328                         # the client from using its cache. We send a few other things just to make sure.
2329                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2330                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2331                         $response->header( 'Pragma: no-cache' );
2332                 }
2333         }
2334
2335         /**
2336          * Transfer styles and JavaScript modules from skin.
2337          *
2338          * @param Skin $sk to load modules for
2339          */
2340         public function loadSkinModules( $sk ) {
2341                 foreach ( $sk->getDefaultModules() as $group => $modules ) {
2342                         if ( $group === 'styles' ) {
2343                                 foreach ( $modules as $key => $moduleMembers ) {
2344                                         $this->addModuleStyles( $moduleMembers );
2345                                 }
2346                         } else {
2347                                 $this->addModules( $modules );
2348                         }
2349                 }
2350         }
2351
2352         /**
2353          * Finally, all the text has been munged and accumulated into
2354          * the object, let's actually output it:
2355          *
2356          * @param bool $return Set to true to get the result as a string rather than sending it
2357          * @return string|null
2358          * @throws Exception
2359          * @throws FatalError
2360          * @throws MWException
2361          */
2362         public function output( $return = false ) {
2363                 global $wgContLang;
2364
2365                 if ( $this->mDoNothing ) {
2366                         return $return ? '' : null;
2367                 }
2368
2369                 $response = $this->getRequest()->response();
2370                 $config = $this->getConfig();
2371
2372                 if ( $this->mRedirect != '' ) {
2373                         # Standards require redirect URLs to be absolute
2374                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2375
2376                         $redirect = $this->mRedirect;
2377                         $code = $this->mRedirectCode;
2378
2379                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2380                                 if ( $code == '301' || $code == '303' ) {
2381                                         if ( !$config->get( 'DebugRedirects' ) ) {
2382                                                 $response->statusHeader( $code );
2383                                         }
2384                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2385                                 }
2386                                 if ( $config->get( 'VaryOnXFP' ) ) {
2387                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2388                                 }
2389                                 $this->sendCacheControl();
2390
2391                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2392                                 if ( $config->get( 'DebugRedirects' ) ) {
2393                                         $url = htmlspecialchars( $redirect );
2394                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2395                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2396                                         print "</body>\n</html>\n";
2397                                 } else {
2398                                         $response->header( 'Location: ' . $redirect );
2399                                 }
2400                         }
2401
2402                         return $return ? '' : null;
2403                 } elseif ( $this->mStatusCode ) {
2404                         $response->statusHeader( $this->mStatusCode );
2405                 }
2406
2407                 # Buffer output; final headers may depend on later processing
2408                 ob_start();
2409
2410                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2411                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2412
2413                 // Avoid Internet Explorer "compatibility view" in IE 8-10, so that
2414                 // jQuery etc. can work correctly.
2415                 $response->header( 'X-UA-Compatible: IE=Edge' );
2416
2417                 if ( !$this->mArticleBodyOnly ) {
2418                         $sk = $this->getSkin();
2419
2420                         if ( $sk->shouldPreloadLogo() ) {
2421                                 $this->addLogoPreloadLinkHeaders();
2422                         }
2423                 }
2424
2425                 $linkHeader = $this->getLinkHeader();
2426                 if ( $linkHeader ) {
2427                         $response->header( $linkHeader );
2428                 }
2429
2430                 // Prevent framing, if requested
2431                 $frameOptions = $this->getFrameOptions();
2432                 if ( $frameOptions ) {
2433                         $response->header( "X-Frame-Options: $frameOptions" );
2434                 }
2435
2436                 if ( $this->mArticleBodyOnly ) {
2437                         echo $this->mBodytext;
2438                 } else {
2439                         // Enable safe mode if requested
2440                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2441                                 $this->disallowUserJs();
2442                         }
2443
2444                         $sk = $this->getSkin();
2445                         $this->loadSkinModules( $sk );
2446
2447                         MWDebug::addModules( $this );
2448
2449                         // Avoid PHP 7.1 warning of passing $this by reference
2450                         $outputPage = $this;
2451                         // Hook that allows last minute changes to the output page, e.g.
2452                         // adding of CSS or Javascript by extensions.
2453                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2454
2455                         try {
2456                                 $sk->outputPage();
2457                         } catch ( Exception $e ) {
2458                                 ob_end_clean(); // bug T129657
2459                                 throw $e;
2460                         }
2461                 }
2462
2463                 try {
2464                         // This hook allows last minute changes to final overall output by modifying output buffer
2465                         Hooks::runWithoutAbort( 'AfterFinalPageOutput', [ $this ] );
2466                 } catch ( Exception $e ) {
2467                         ob_end_clean(); // bug T129657
2468                         throw $e;
2469                 }
2470
2471                 $this->sendCacheControl();
2472
2473                 if ( $return ) {
2474                         return ob_get_clean();
2475                 } else {
2476                         ob_end_flush();
2477                         return null;
2478                 }
2479         }
2480
2481         /**
2482          * Prepare this object to display an error page; disable caching and
2483          * indexing, clear the current text and redirect, set the page's title
2484          * and optionally an custom HTML title (content of the "<title>" tag).
2485          *
2486          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2487          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2488          *                   optional, if not passed the "<title>" attribute will be
2489          *                   based on $pageTitle
2490          */
2491         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2492                 $this->setPageTitle( $pageTitle );
2493                 if ( $htmlTitle !== false ) {
2494                         $this->setHTMLTitle( $htmlTitle );
2495                 }
2496                 $this->setRobotPolicy( 'noindex,nofollow' );
2497                 $this->setArticleRelated( false );
2498                 $this->enableClientCache( false );
2499                 $this->mRedirect = '';
2500                 $this->clearSubtitle();
2501                 $this->clearHTML();
2502         }
2503
2504         /**
2505          * Output a standard error page
2506          *
2507          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2508          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2509          * showErrorPage( 'titlemsg', $messageObject );
2510          * showErrorPage( $titleMessageObject, $messageObject );
2511          *
2512          * @param string|Message $title Message key (string) for page title, or a Message object
2513          * @param string|Message $msg Message key (string) for page text, or a Message object
2514          * @param array $params Message parameters; ignored if $msg is a Message object
2515          */
2516         public function showErrorPage( $title, $msg, $params = [] ) {
2517                 if ( !$title instanceof Message ) {
2518                         $title = $this->msg( $title );
2519                 }
2520
2521                 $this->prepareErrorPage( $title );
2522
2523                 if ( $msg instanceof Message ) {
2524                         if ( $params !== [] ) {
2525                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2526                                         . 'is discarded when the $msg argument is a Message object instead of '
2527                                         . 'a string.', E_USER_NOTICE );
2528                         }
2529                         $this->addHTML( $msg->parseAsBlock() );
2530                 } else {
2531                         $this->addWikiMsgArray( $msg, $params );
2532                 }
2533
2534                 $this->returnToMain();
2535         }
2536
2537         /**
2538          * Output a standard permission error page
2539          *
2540          * @param array $errors Error message keys or [key, param...] arrays
2541          * @param string $action Action that was denied or null if unknown
2542          */
2543         public function showPermissionsErrorPage( array $errors, $action = null ) {
2544                 foreach ( $errors as $key => $error ) {
2545                         $errors[$key] = (array)$error;
2546                 }
2547
2548                 // For some action (read, edit, create and upload), display a "login to do this action"
2549                 // error if all of the following conditions are met:
2550                 // 1. the user is not logged in
2551                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2552                 // 3. the error can be avoided simply by logging in
2553                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2554                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2555                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2556                         && ( User::groupHasPermission( 'user', $action )
2557                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2558                 ) {
2559                         $displayReturnto = null;
2560
2561                         # Due to T34276, if a user does not have read permissions,
2562                         # $this->getTitle() will just give Special:Badtitle, which is
2563                         # not especially useful as a returnto parameter. Use the title
2564                         # from the request instead, if there was one.
2565                         $request = $this->getRequest();
2566                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2567                         if ( $action == 'edit' ) {
2568                                 $msg = 'whitelistedittext';
2569                                 $displayReturnto = $returnto;
2570                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2571                                 $msg = 'nocreatetext';
2572                         } elseif ( $action == 'upload' ) {
2573                                 $msg = 'uploadnologintext';
2574                         } else { # Read
2575                                 $msg = 'loginreqpagetext';
2576                                 $displayReturnto = Title::newMainPage();
2577                         }
2578
2579                         $query = [];
2580
2581                         if ( $returnto ) {
2582                                 $query['returnto'] = $returnto->getPrefixedText();
2583
2584                                 if ( !$request->wasPosted() ) {
2585                                         $returntoquery = $request->getValues();
2586                                         unset( $returntoquery['title'] );
2587                                         unset( $returntoquery['returnto'] );
2588                                         unset( $returntoquery['returntoquery'] );
2589                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2590                                 }
2591                         }
2592                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2593                         $loginLink = $linkRenderer->makeKnownLink(
2594                                 SpecialPage::getTitleFor( 'Userlogin' ),
2595                                 $this->msg( 'loginreqlink' )->text(),
2596                                 [],
2597                                 $query
2598                         );
2599
2600                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2601                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2602
2603                         # Don't return to a page the user can't read otherwise
2604                         # we'll end up in a pointless loop
2605                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2606                                 $this->returnToMain( null, $displayReturnto );
2607                         }
2608                 } else {
2609                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2610                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2611                 }
2612         }
2613
2614         /**
2615          * Display an error page indicating that a given version of MediaWiki is
2616          * required to use it
2617          *
2618          * @param mixed $version The version of MediaWiki needed to use the page
2619          */
2620         public function versionRequired( $version ) {
2621                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2622
2623                 $this->addWikiMsg( 'versionrequiredtext', $version );
2624                 $this->returnToMain();
2625         }
2626
2627         /**
2628          * Format a list of error messages
2629          *
2630          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2631          * @param string $action Action that was denied or null if unknown
2632          * @return string The wikitext error-messages, formatted into a list.
2633          */
2634         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2635                 if ( $action == null ) {
2636                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2637                 } else {
2638                         $action_desc = $this->msg( "action-$action" )->plain();
2639                         $text = $this->msg(
2640                                 'permissionserrorstext-withaction',
2641                                 count( $errors ),
2642                                 $action_desc
2643                         )->plain() . "\n\n";
2644                 }
2645
2646                 if ( count( $errors ) > 1 ) {
2647                         $text .= '<ul class="permissions-errors">' . "\n";
2648
2649                         foreach ( $errors as $error ) {
2650                                 $text .= '<li>';
2651                                 $text .= call_user_func_array( [ $this, 'msg' ], $error )->plain();
2652                                 $text .= "</li>\n";
2653                         }
2654                         $text .= '</ul>';
2655                 } else {
2656                         $text .= "<div class=\"permissions-errors\">\n" .
2657                                         call_user_func_array( [ $this, 'msg' ], reset( $errors ) )->plain() .
2658                                         "\n</div>";
2659                 }
2660
2661                 return $text;
2662         }
2663
2664         /**
2665          * Show a warning about replica DB lag
2666          *
2667          * If the lag is higher than $wgSlaveLagCritical seconds,
2668          * then the warning is a bit more obvious. If the lag is
2669          * lower than $wgSlaveLagWarning, then no warning is shown.
2670          *
2671          * @param int $lag Slave lag
2672          */
2673         public function showLagWarning( $lag ) {
2674                 $config = $this->getConfig();
2675                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2676                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2677                         $message = $lag < $config->get( 'SlaveLagCritical' )
2678                                 ? 'lag-warn-normal'
2679                                 : 'lag-warn-high';
2680                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2681                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2682                 }
2683         }
2684
2685         public function showFatalError( $message ) {
2686                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2687
2688                 $this->addHTML( $message );
2689         }
2690
2691         public function showUnexpectedValueError( $name, $val ) {
2692                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2693         }
2694
2695         public function showFileCopyError( $old, $new ) {
2696                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2697         }
2698
2699         public function showFileRenameError( $old, $new ) {
2700                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2701         }
2702
2703         public function showFileDeleteError( $name ) {
2704                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2705         }
2706
2707         public function showFileNotFoundError( $name ) {
2708                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2709         }
2710
2711         /**
2712          * Add a "return to" link pointing to a specified title
2713          *
2714          * @param Title $title Title to link
2715          * @param array $query Query string parameters
2716          * @param string $text Text of the link (input is not escaped)
2717          * @param array $options Options array to pass to Linker
2718          */
2719         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2720                 $linkRenderer = MediaWikiServices::getInstance()
2721                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
2722                 $link = $this->msg( 'returnto' )->rawParams(
2723                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
2724                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2725         }
2726
2727         /**
2728          * Add a "return to" link pointing to a specified title,
2729          * or the title indicated in the request, or else the main page
2730          *
2731          * @param mixed $unused
2732          * @param Title|string $returnto Title or String to return to
2733          * @param string $returntoquery Query string for the return to link
2734          */
2735         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2736                 if ( $returnto == null ) {
2737                         $returnto = $this->getRequest()->getText( 'returnto' );
2738                 }
2739
2740                 if ( $returntoquery == null ) {
2741                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2742                 }
2743
2744                 if ( $returnto === '' ) {
2745                         $returnto = Title::newMainPage();
2746                 }
2747
2748                 if ( is_object( $returnto ) ) {
2749                         $titleObj = $returnto;
2750                 } else {
2751                         $titleObj = Title::newFromText( $returnto );
2752                 }
2753                 // We don't want people to return to external interwiki. That
2754                 // might potentially be used as part of a phishing scheme
2755                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
2756                         $titleObj = Title::newMainPage();
2757                 }
2758
2759                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2760         }
2761
2762         private function getRlClientContext() {
2763                 if ( !$this->rlClientContext ) {
2764                         $query = ResourceLoader::makeLoaderQuery(
2765                                 [], // modules; not relevant
2766                                 $this->getLanguage()->getCode(),
2767                                 $this->getSkin()->getSkinName(),
2768                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2769                                 null, // version; not relevant
2770                                 ResourceLoader::inDebugMode(),
2771                                 null, // only; not relevant
2772                                 $this->isPrintable(),
2773                                 $this->getRequest()->getBool( 'handheld' )
2774                         );
2775                         $this->rlClientContext = new ResourceLoaderContext(
2776                                 $this->getResourceLoader(),
2777                                 new FauxRequest( $query )
2778                         );
2779                         if ( $this->contentOverrideCallbacks ) {
2780                                 $this->rlClientContext = new DerivativeResourceLoaderContext( $this->rlClientContext );
2781                                 $this->rlClientContext->setContentOverrideCallback( function ( Title $title ) {
2782                                         foreach ( $this->contentOverrideCallbacks as $callback ) {
2783                                                 $content = call_user_func( $callback, $title );
2784                                                 if ( $content !== null ) {
2785                                                         return $content;
2786                                                 }
2787                                         }
2788                                         return null;
2789                                 } );
2790                         }
2791                 }
2792                 return $this->rlClientContext;
2793         }
2794
2795         /**
2796          * Call this to freeze the module queue and JS config and create a formatter.
2797          *
2798          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2799          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2800          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2801          * the module filters retroactively. Skins and extension hooks may also add modules until very
2802          * late in the request lifecycle.
2803          *
2804          * @return ResourceLoaderClientHtml
2805          */
2806         public function getRlClient() {
2807                 if ( !$this->rlClient ) {
2808                         $context = $this->getRlClientContext();
2809                         $rl = $this->getResourceLoader();
2810                         $this->addModules( [
2811                                 'user',
2812                                 'user.options',
2813                                 'user.tokens',
2814                         ] );
2815                         $this->addModuleStyles( [
2816                                 'site.styles',
2817                                 'noscript',
2818                                 'user.styles',
2819                         ] );
2820                         $this->getSkin()->setupSkinUserCss( $this );
2821
2822                         // Prepare exempt modules for buildExemptModules()
2823                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2824                         $exemptStates = [];
2825                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2826
2827                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2828                         // Separate user-specific batch for improved cache-hit ratio.
2829                         $userBatch = [ 'user.styles', 'user' ];
2830                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2831                         $dbr = wfGetDB( DB_REPLICA );
2832                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2833                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2834
2835                         // Filter out modules handled by buildExemptModules()
2836                         $moduleStyles = array_filter( $moduleStyles,
2837                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2838                                         $module = $rl->getModule( $name );
2839                                         if ( $module ) {
2840                                                 $group = $module->getGroup();
2841                                                 if ( isset( $exemptGroups[$group] ) ) {
2842                                                         $exemptStates[$name] = 'ready';
2843                                                         if ( !$module->isKnownEmpty( $context ) ) {
2844                                                                 // E.g. Don't output empty <styles>
2845                                                                 $exemptGroups[$group][] = $name;
2846                                                         }
2847                                                         return false;
2848                                                 }
2849                                         }
2850                                         return true;
2851                                 }
2852                         );
2853                         $this->rlExemptStyleModules = $exemptGroups;
2854
2855                         $rlClient = new ResourceLoaderClientHtml( $context, [
2856                                 'target' => $this->getTarget(),
2857                         ] );
2858                         $rlClient->setConfig( $this->getJSVars() );
2859                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2860                         $rlClient->setModuleStyles( $moduleStyles );
2861                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2862                         $rlClient->setExemptStates( $exemptStates );
2863                         $this->rlClient = $rlClient;
2864                 }
2865                 return $this->rlClient;
2866         }
2867
2868         /**
2869          * @param Skin $sk The given Skin
2870          * @param bool $includeStyle Unused
2871          * @return string The doctype, opening "<html>", and head element.
2872          */
2873         public function headElement( Skin $sk, $includeStyle = true ) {
2874                 global $wgContLang;
2875
2876                 $userdir = $this->getLanguage()->getDir();
2877                 $sitedir = $wgContLang->getDir();
2878
2879                 $pieces = [];
2880                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2881                         $this->getRlClient()->getDocumentAttributes(),
2882                         $sk->getHtmlElementAttributes()
2883                 ) );
2884                 $pieces[] = Html::openElement( 'head' );
2885
2886                 if ( $this->getHTMLTitle() == '' ) {
2887                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2888                 }
2889
2890                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2891                         // Add <meta charset="UTF-8">
2892                         // This should be before <title> since it defines the charset used by
2893                         // text including the text inside <title>.
2894                         // The spec recommends defining XHTML5's charset using the XML declaration
2895                         // instead of meta.
2896                         // Our XML declaration is output by Html::htmlHeader.
2897                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2898                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2899                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2900                 }
2901
2902                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2903                 $pieces[] = $this->getRlClient()->getHeadHtml();
2904                 $pieces[] = $this->buildExemptModules();
2905                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2906                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2907
2908                 // Use an IE conditional comment to serve the script only to old IE
2909                 $pieces[] = '<!--[if lt IE 9]>' .
2910                         ResourceLoaderClientHtml::makeLoad(
2911                                 ResourceLoaderContext::newDummyContext(),
2912                                 [ 'html5shiv' ],
2913                                 ResourceLoaderModule::TYPE_SCRIPTS,
2914                                 [ 'sync' => true ]
2915                         ) .
2916                         '<![endif]-->';
2917
2918                 $pieces[] = Html::closeElement( 'head' );
2919
2920                 $bodyClasses = $this->mAdditionalBodyClasses;
2921                 $bodyClasses[] = 'mediawiki';
2922
2923                 # Classes for LTR/RTL directionality support
2924                 $bodyClasses[] = $userdir;
2925                 $bodyClasses[] = "sitedir-$sitedir";
2926
2927                 $underline = $this->getUser()->getOption( 'underline' );
2928                 if ( $underline < 2 ) {
2929                         // The following classes can be used here:
2930                         // * mw-underline-always
2931                         // * mw-underline-never
2932                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2933                 }
2934
2935                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2936                         # A <body> class is probably not the best way to do this . . .
2937                         $bodyClasses[] = 'capitalize-all-nouns';
2938                 }
2939
2940                 // Parser feature migration class
2941                 // The idea is that this will eventually be removed, after the wikitext
2942                 // which requires it is cleaned up.
2943                 $bodyClasses[] = 'mw-hide-empty-elt';
2944
2945                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2946                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2947                 $bodyClasses[] =
2948                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2949
2950                 $bodyAttrs = [];
2951                 // While the implode() is not strictly needed, it's used for backwards compatibility
2952                 // (this used to be built as a string and hooks likely still expect that).
2953                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2954
2955                 // Allow skins and extensions to add body attributes they need
2956                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2957                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2958
2959                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2960
2961                 return self::combineWrappedStrings( $pieces );
2962         }
2963
2964         /**
2965          * Get a ResourceLoader object associated with this OutputPage
2966          *
2967          * @return ResourceLoader
2968          */
2969         public function getResourceLoader() {
2970                 if ( is_null( $this->mResourceLoader ) ) {
2971                         $this->mResourceLoader = new ResourceLoader(
2972                                 $this->getConfig(),
2973                                 LoggerFactory::getInstance( 'resourceloader' )
2974                         );
2975                 }
2976                 return $this->mResourceLoader;
2977         }
2978
2979         /**
2980          * Explicily load or embed modules on a page.
2981          *
2982          * @param array|string $modules One or more module names
2983          * @param string $only ResourceLoaderModule TYPE_ class constant
2984          * @param array $extraQuery [optional] Array with extra query parameters for the request
2985          * @return string|WrappedStringList HTML
2986          */
2987         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2988                 // Apply 'target' and 'origin' filters
2989                 $modules = $this->filterModules( (array)$modules, null, $only );
2990
2991                 return ResourceLoaderClientHtml::makeLoad(
2992                         $this->getRlClientContext(),
2993                         $modules,
2994                         $only,
2995                         $extraQuery
2996                 );
2997         }
2998
2999         /**
3000          * Combine WrappedString chunks and filter out empty ones
3001          *
3002          * @param array $chunks
3003          * @return string|WrappedStringList HTML
3004          */
3005         protected static function combineWrappedStrings( array $chunks ) {
3006                 // Filter out empty values
3007                 $chunks = array_filter( $chunks, 'strlen' );
3008                 return WrappedString::join( "\n", $chunks );
3009         }
3010
3011         /**
3012          * JS stuff to put at the bottom of the `<body>`.
3013          * These are legacy scripts ($this->mScripts), and user JS.
3014          *
3015          * @return string|WrappedStringList HTML
3016          */
3017         public function getBottomScripts() {
3018                 $chunks = [];
3019                 $chunks[] = $this->getRlClient()->getBodyHtml();
3020
3021                 // Legacy non-ResourceLoader scripts
3022                 $chunks[] = $this->mScripts;
3023
3024                 if ( $this->limitReportJSData ) {
3025                         $chunks[] = ResourceLoader::makeInlineScript(
3026                                 ResourceLoader::makeConfigSetScript(
3027                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3028                                 )
3029                         );
3030                 }
3031
3032                 return self::combineWrappedStrings( $chunks );
3033         }
3034
3035         /**
3036          * Get the javascript config vars to include on this page
3037          *
3038          * @return array Array of javascript config vars
3039          * @since 1.23
3040          */
3041         public function getJsConfigVars() {
3042                 return $this->mJsConfigVars;
3043         }
3044
3045         /**
3046          * Add one or more variables to be set in mw.config in JavaScript
3047          *
3048          * @param string|array $keys Key or array of key/value pairs
3049          * @param mixed $value [optional] Value of the configuration variable
3050          */
3051         public function addJsConfigVars( $keys, $value = null ) {
3052                 if ( is_array( $keys ) ) {
3053                         foreach ( $keys as $key => $value ) {
3054                                 $this->mJsConfigVars[$key] = $value;
3055                         }
3056                         return;
3057                 }
3058
3059                 $this->mJsConfigVars[$keys] = $value;
3060         }
3061
3062         /**
3063          * Get an array containing the variables to be set in mw.config in JavaScript.
3064          *
3065          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3066          * - in other words, page-independent/site-wide variables (without state).
3067          * You will only be adding bloat to the html page and causing page caches to
3068          * have to be purged on configuration changes.
3069          * @return array
3070          */
3071         public function getJSVars() {
3072                 global $wgContLang;
3073
3074                 $curRevisionId = 0;
3075                 $articleId = 0;
3076                 $canonicalSpecialPageName = false; # T23115
3077
3078                 $title = $this->getTitle();
3079                 $ns = $title->getNamespace();
3080                 $canonicalNamespace = MWNamespace::exists( $ns )
3081                         ? MWNamespace::getCanonicalName( $ns )
3082                         : $title->getNsText();
3083
3084                 $sk = $this->getSkin();
3085                 // Get the relevant title so that AJAX features can use the correct page name
3086                 // when making API requests from certain special pages (T36972).
3087                 $relevantTitle = $sk->getRelevantTitle();
3088                 $relevantUser = $sk->getRelevantUser();
3089
3090                 if ( $ns == NS_SPECIAL ) {
3091                         list( $canonicalSpecialPageName, /*...*/ ) =
3092                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3093                 } elseif ( $this->canUseWikiPage() ) {
3094                         $wikiPage = $this->getWikiPage();
3095                         $curRevisionId = $wikiPage->getLatest();
3096                         $articleId = $wikiPage->getId();
3097                 }
3098
3099                 $lang = $title->getPageViewLanguage();
3100
3101                 // Pre-process information
3102                 $separatorTransTable = $lang->separatorTransformTable();
3103                 $separatorTransTable = $separatorTransTable ? $separatorTransTable : [];
3104                 $compactSeparatorTransTable = [
3105                         implode( "\t", array_keys( $separatorTransTable ) ),
3106                         implode( "\t", $separatorTransTable ),
3107                 ];
3108                 $digitTransTable = $lang->digitTransformTable();
3109                 $digitTransTable = $digitTransTable ? $digitTransTable : [];
3110                 $compactDigitTransTable = [
3111                         implode( "\t", array_keys( $digitTransTable ) ),
3112                         implode( "\t", $digitTransTable ),
3113                 ];
3114
3115                 $user = $this->getUser();
3116
3117                 $vars = [
3118                         'wgCanonicalNamespace' => $canonicalNamespace,
3119                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3120                         'wgNamespaceNumber' => $title->getNamespace(),
3121                         'wgPageName' => $title->getPrefixedDBkey(),
3122                         'wgTitle' => $title->getText(),
3123                         'wgCurRevisionId' => $curRevisionId,
3124                         'wgRevisionId' => (int)$this->getRevisionId(),
3125                         'wgArticleId' => $articleId,
3126                         'wgIsArticle' => $this->isArticle(),
3127                         'wgIsRedirect' => $title->isRedirect(),
3128                         'wgAction' => Action::getActionName( $this->getContext() ),
3129                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3130                         'wgUserGroups' => $user->getEffectiveGroups(),
3131                         'wgCategories' => $this->getCategories(),
3132                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3133                         'wgPageContentLanguage' => $lang->getCode(),
3134                         'wgPageContentModel' => $title->getContentModel(),
3135                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3136                         'wgDigitTransformTable' => $compactDigitTransTable,
3137                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3138                         'wgMonthNames' => $lang->getMonthNamesArray(),
3139                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3140                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3141                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3142                         'wgRequestId' => WebRequest::getRequestId(),
3143                 ];
3144
3145                 if ( $user->isLoggedIn() ) {
3146                         $vars['wgUserId'] = $user->getId();
3147                         $vars['wgUserEditCount'] = $user->getEditCount();
3148                         $userReg = $user->getRegistration();
3149                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3150                         // Get the revision ID of the oldest new message on the user's talk
3151                         // page. This can be used for constructing new message alerts on
3152                         // the client side.
3153                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3154                 }
3155
3156                 if ( $wgContLang->hasVariants() ) {
3157                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3158                 }
3159                 // Same test as SkinTemplate
3160                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3161                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3162
3163                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3164                         && $relevantTitle->quickUserCan( 'edit', $user )
3165                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3166
3167                 foreach ( $title->getRestrictionTypes() as $type ) {
3168                         // Following keys are set in $vars:
3169                         // wgRestrictionCreate, wgRestrictionEdit, wgRestrictionMove, wgRestrictionUpload
3170                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3171                 }
3172
3173                 if ( $title->isMainPage() ) {
3174                         $vars['wgIsMainPage'] = true;
3175                 }
3176
3177                 if ( $this->mRedirectedFrom ) {
3178                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3179                 }
3180
3181                 if ( $relevantUser ) {
3182                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3183                 }
3184
3185                 // Allow extensions to add their custom variables to the mw.config map.
3186                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3187                 // page-dependant but site-wide (without state).
3188                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3189                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3190
3191                 // Merge in variables from addJsConfigVars last
3192                 return array_merge( $vars, $this->getJsConfigVars() );
3193         }
3194
3195         /**
3196          * To make it harder for someone to slip a user a fake
3197          * JavaScript or CSS preview, a random token
3198          * is associated with the login session. If it's not
3199          * passed back with the preview request, we won't render
3200          * the code.
3201          *
3202          * @return bool
3203          */
3204         public function userCanPreview() {
3205                 $request = $this->getRequest();
3206                 if (
3207                         $request->getVal( 'action' ) !== 'submit' ||
3208                         !$request->wasPosted()
3209                 ) {
3210                         return false;
3211                 }
3212
3213                 $user = $this->getUser();
3214
3215                 if ( !$user->isLoggedIn() ) {
3216                         // Anons have predictable edit tokens
3217                         return false;
3218                 }
3219                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3220                         return false;
3221                 }
3222
3223                 $title = $this->getTitle();
3224                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3225                 if ( count( $errors ) !== 0 ) {
3226                         return false;
3227                 }
3228
3229                 return true;
3230         }
3231
3232         /**
3233          * @return array Array in format "link name or number => 'link html'".
3234          */
3235         public function getHeadLinksArray() {
3236                 global $wgVersion;
3237
3238                 $tags = [];
3239                 $config = $this->getConfig();
3240
3241                 $canonicalUrl = $this->mCanonicalUrl;
3242
3243                 $tags['meta-generator'] = Html::element( 'meta', [
3244                         'name' => 'generator',
3245                         'content' => "MediaWiki $wgVersion",
3246                 ] );
3247
3248                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3249                         // Per https://w3c.github.io/webappsec-referrer-policy/#unknown-policy-values
3250                         // fallbacks should come before the primary value so we need to reverse the array.
3251                         foreach ( array_reverse( (array)$config->get( 'ReferrerPolicy' ) ) as $i => $policy ) {
3252                                 $tags["meta-referrer-$i"] = Html::element( 'meta', [
3253                                         'name' => 'referrer',
3254                                         'content' => $policy,
3255                                 ] );
3256                         }
3257                 }
3258
3259                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3260                 if ( $p !== 'index,follow' ) {
3261                         // http://www.robotstxt.org/wc/meta-user.html
3262                         // Only show if it's different from the default robots policy
3263                         $tags['meta-robots'] = Html::element( 'meta', [
3264                                 'name' => 'robots',
3265                                 'content' => $p,
3266                         ] );
3267                 }
3268
3269                 foreach ( $this->mMetatags as $tag ) {
3270                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3271                                 $a = 'http-equiv';
3272                                 $tag[0] = substr( $tag[0], 5 );
3273                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3274                                 $a = 'property';
3275                         } else {
3276                                 $a = 'name';
3277                         }
3278                         $tagName = "meta-{$tag[0]}";
3279                         if ( isset( $tags[$tagName] ) ) {
3280                                 $tagName .= $tag[1];
3281                         }
3282                         $tags[$tagName] = Html::element( 'meta',
3283                                 [
3284                                         $a => $tag[0],
3285                                         'content' => $tag[1]
3286                                 ]
3287                         );
3288                 }
3289
3290                 foreach ( $this->mLinktags as $tag ) {
3291                         $tags[] = Html::element( 'link', $tag );
3292                 }
3293
3294                 # Universal edit button
3295                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3296                         $user = $this->getUser();
3297                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3298                                 && ( $this->getTitle()->exists() ||
3299                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3300                         ) {
3301                                 // Original UniversalEditButton
3302                                 $msg = $this->msg( 'edit' )->text();
3303                                 $tags['universal-edit-button'] = Html::element( 'link', [
3304                                         'rel' => 'alternate',
3305                                         'type' => 'application/x-wiki',
3306                                         'title' => $msg,
3307                                         'href' => $this->getTitle()->getEditURL(),
3308                                 ] );
3309                                 // Alternate edit link
3310                                 $tags['alternative-edit'] = Html::element( 'link', [
3311                                         'rel' => 'edit',
3312                                         'title' => $msg,
3313                                         'href' => $this->getTitle()->getEditURL(),
3314                                 ] );
3315                         }
3316                 }
3317
3318                 # Generally the order of the favicon and apple-touch-icon links
3319                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3320                 # uses whichever one appears later in the HTML source. Make sure
3321                 # apple-touch-icon is specified first to avoid this.
3322                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3323                         $tags['apple-touch-icon'] = Html::element( 'link', [
3324                                 'rel' => 'apple-touch-icon',
3325                                 'href' => $config->get( 'AppleTouchIcon' )
3326                         ] );
3327                 }
3328
3329                 if ( $config->get( 'Favicon' ) !== false ) {
3330                         $tags['favicon'] = Html::element( 'link', [
3331                                 'rel' => 'shortcut icon',
3332                                 'href' => $config->get( 'Favicon' )
3333                         ] );
3334                 }
3335
3336                 # OpenSearch description link
3337                 $tags['opensearch'] = Html::element( 'link', [
3338                         'rel' => 'search',
3339                         'type' => 'application/opensearchdescription+xml',
3340                         'href' => wfScript( 'opensearch_desc' ),
3341                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3342                 ] );
3343
3344                 # Real Simple Discovery link, provides auto-discovery information
3345                 # for the MediaWiki API (and potentially additional custom API
3346                 # support such as WordPress or Twitter-compatible APIs for a
3347                 # blogging extension, etc)
3348                 $tags['rsd'] = Html::element( 'link', [
3349                         'rel' => 'EditURI',
3350                         'type' => 'application/rsd+xml',
3351                         // Output a protocol-relative URL here if $wgServer is protocol-relative.
3352                         // Whether RSD accepts relative or protocol-relative URLs is completely
3353                         // undocumented, though.
3354                         'href' => wfExpandUrl( wfAppendQuery(
3355                                 wfScript( 'api' ),
3356                                 [ 'action' => 'rsd' ] ),
3357                                 PROTO_RELATIVE
3358                         ),
3359                 ] );
3360
3361                 # Language variants
3362                 if ( !$config->get( 'DisableLangConversion' ) ) {
3363                         $lang = $this->getTitle()->getPageLanguage();
3364                         if ( $lang->hasVariants() ) {
3365                                 $variants = $lang->getVariants();
3366                                 foreach ( $variants as $variant ) {
3367                                         $tags["variant-$variant"] = Html::element( 'link', [
3368                                                 'rel' => 'alternate',
3369                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3370                                                 'href' => $this->getTitle()->getLocalURL(
3371                                                         [ 'variant' => $variant ] )
3372                                                 ]
3373                                         );
3374                                 }
3375                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3376                                 $tags["variant-x-default"] = Html::element( 'link', [
3377                                         'rel' => 'alternate',
3378                                         'hreflang' => 'x-default',
3379                                         'href' => $this->getTitle()->getLocalURL() ] );
3380                         }
3381                 }
3382
3383                 # Copyright
3384                 if ( $this->copyrightUrl !== null ) {
3385                         $copyright = $this->copyrightUrl;
3386                 } else {
3387                         $copyright = '';
3388                         if ( $config->get( 'RightsPage' ) ) {
3389                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3390
3391                                 if ( $copy ) {
3392                                         $copyright = $copy->getLocalURL();
3393                                 }
3394                         }
3395
3396                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3397                                 $copyright = $config->get( 'RightsUrl' );
3398                         }
3399                 }
3400
3401                 if ( $copyright ) {
3402                         $tags['copyright'] = Html::element( 'link', [
3403                                 'rel' => 'license',
3404                                 'href' => $copyright ]
3405                         );
3406                 }
3407
3408                 # Feeds
3409                 if ( $config->get( 'Feed' ) ) {
3410                         $feedLinks = [];
3411
3412                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3413                                 # Use the page name for the title.  In principle, this could
3414                                 # lead to issues with having the same name for different feeds
3415                                 # corresponding to the same page, but we can't avoid that at
3416                                 # this low a level.
3417
3418                                 $feedLinks[] = $this->feedLink(
3419                                         $format,
3420                                         $link,
3421                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3422                                         $this->msg(
3423                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3424                                         )->text()
3425                                 );
3426                         }
3427
3428                         # Recent changes feed should appear on every page (except recentchanges,
3429                         # that would be redundant). Put it after the per-page feed to avoid
3430                         # changing existing behavior. It's still available, probably via a
3431                         # menu in your browser. Some sites might have a different feed they'd
3432                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3433                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3434                         # If so, use it instead.
3435                         $sitename = $config->get( 'Sitename' );
3436                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3437                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3438                                         // Note, this->feedLink escapes the url.
3439                                         $feedLinks[] = $this->feedLink(
3440                                                 $type,
3441                                                 $feedUrl,
3442                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3443                                         );
3444                                 }
3445                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3446                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3447                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3448                                         $feedLinks[] = $this->feedLink(
3449                                                 $format,
3450                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3451                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3452                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3453                                         );
3454                                 }
3455                         }
3456
3457                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3458                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3459                         # use OutputPage::addFeedLink() instead.
3460                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3461
3462                         $tags += $feedLinks;
3463                 }
3464
3465                 # Canonical URL
3466                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3467                         if ( $canonicalUrl !== false ) {
3468                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3469                         } else {
3470                                 if ( $this->isArticleRelated() ) {
3471                                         // This affects all requests where "setArticleRelated" is true. This is
3472                                         // typically all requests that show content (query title, curid, oldid, diff),
3473                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3474                                         // It does not apply to File pages and Special pages.
3475                                         // 'history' and 'info' actions address page metadata rather than the page
3476                                         // content itself, so they may not be canonicalized to the view page url.
3477                                         // TODO: this ought to be better encapsulated in the Action class.
3478                                         $action = Action::getActionName( $this->getContext() );
3479                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3480                                                 $query = "action={$action}";
3481                                         } else {
3482                                                 $query = '';
3483                                         }
3484                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3485                                 } else {
3486                                         $reqUrl = $this->getRequest()->getRequestURL();
3487                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3488                                 }
3489                         }
3490                 }
3491                 if ( $canonicalUrl !== false ) {
3492                         $tags[] = Html::element( 'link', [
3493                                 'rel' => 'canonical',
3494                                 'href' => $canonicalUrl
3495                         ] );
3496                 }
3497
3498                 return $tags;
3499         }
3500
3501         /**
3502          * Generate a "<link rel/>" for a feed.
3503          *
3504          * @param string $type Feed type
3505          * @param string $url URL to the feed
3506          * @param string $text Value of the "title" attribute
3507          * @return string HTML fragment
3508          */
3509         private function feedLink( $type, $url, $text ) {
3510                 return Html::element( 'link', [
3511                         'rel' => 'alternate',
3512                         'type' => "application/$type+xml",
3513                         'title' => $text,
3514                         'href' => $url ]
3515                 );
3516         }
3517
3518         /**
3519          * Add a local or specified stylesheet, with the given media options.
3520          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3521          *
3522          * @param string $style URL to the file
3523          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3524          * @param string $condition For IE conditional comments, specifying an IE version
3525          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3526          */
3527         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3528                 $options = [];
3529                 if ( $media ) {
3530                         $options['media'] = $media;
3531                 }
3532                 if ( $condition ) {
3533                         $options['condition'] = $condition;
3534                 }
3535                 if ( $dir ) {
3536                         $options['dir'] = $dir;
3537                 }
3538                 $this->styles[$style] = $options;
3539         }
3540
3541         /**
3542          * Adds inline CSS styles
3543          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3544          *
3545          * @param mixed $style_css Inline CSS
3546          * @param string $flip Set to 'flip' to flip the CSS if needed
3547          */
3548         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3549                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3550                         # If wanted, and the interface is right-to-left, flip the CSS
3551                         $style_css = CSSJanus::transform( $style_css, true, false );
3552                 }
3553                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3554         }
3555
3556         /**
3557          * Build exempt modules and legacy non-ResourceLoader styles.
3558          *
3559          * @return string|WrappedStringList HTML
3560          */
3561         protected function buildExemptModules() {
3562                 $chunks = [];
3563                 // Things that go after the ResourceLoaderDynamicStyles marker
3564                 $append = [];
3565
3566                 // We want site, private and user styles to override dynamically added styles from
3567                 // general modules, but we want dynamically added styles to override statically added
3568                 // style modules. So the order has to be:
3569                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3570                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3571                 // - ResourceLoaderDynamicStyles marker
3572                 // - site/private/user styles
3573
3574                 // Add legacy styles added through addStyle()/addInlineStyle() here
3575                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3576
3577                 $chunks[] = Html::element(
3578                         'meta',
3579                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3580                 );
3581
3582                 $separateReq = [ 'site.styles', 'user.styles' ];
3583                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3584                         // Combinable modules
3585                         $chunks[] = $this->makeResourceLoaderLink(
3586                                 array_diff( $moduleNames, $separateReq ),
3587                                 ResourceLoaderModule::TYPE_STYLES
3588                         );
3589
3590                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3591                                 // These require their own dedicated request in order to support "@import"
3592                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3593                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3594                                         ResourceLoaderModule::TYPE_STYLES
3595                                 );
3596                         }
3597                 }
3598
3599                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3600         }
3601
3602         /**
3603          * @return array
3604          */
3605         public function buildCssLinksArray() {
3606                 $links = [];
3607
3608                 foreach ( $this->styles as $file => $options ) {
3609                         $link = $this->styleLink( $file, $options );
3610                         if ( $link ) {
3611                                 $links[$file] = $link;
3612                         }
3613                 }
3614                 return $links;
3615         }
3616
3617         /**
3618          * Generate \<link\> tags for stylesheets
3619          *
3620          * @param string $style URL to the file
3621          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3622          * @return string HTML fragment
3623          */
3624         protected function styleLink( $style, array $options ) {
3625                 if ( isset( $options['dir'] ) ) {
3626                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3627                                 return '';
3628                         }
3629                 }
3630
3631                 if ( isset( $options['media'] ) ) {
3632                         $media = self::transformCssMedia( $options['media'] );
3633                         if ( is_null( $media ) ) {
3634                                 return '';
3635                         }
3636                 } else {
3637                         $media = 'all';
3638                 }
3639
3640                 if ( substr( $style, 0, 1 ) == '/' ||
3641                         substr( $style, 0, 5 ) == 'http:' ||
3642                         substr( $style, 0, 6 ) == 'https:' ) {
3643                         $url = $style;
3644                 } else {
3645                         $config = $this->getConfig();
3646                         $url = $config->get( 'StylePath' ) . '/' . $style . '?' .
3647                                 $config->get( 'StyleVersion' );
3648                 }
3649
3650                 $link = Html::linkedStyle( $url, $media );
3651
3652                 if ( isset( $options['condition'] ) ) {
3653                         $condition = htmlspecialchars( $options['condition'] );
3654                         $link = "<!--[if $condition]>$link<![endif]-->";
3655                 }
3656                 return $link;
3657         }
3658
3659         /**
3660          * Transform path to web-accessible static resource.
3661          *
3662          * This is used to add a validation hash as query string.
3663          * This aids various behaviors:
3664          *
3665          * - Put long Cache-Control max-age headers on responses for improved
3666          *   cache performance.
3667          * - Get the correct version of a file as expected by the current page.
3668          * - Instantly get the updated version of a file after deployment.
3669          *
3670          * Avoid using this for urls included in HTML as otherwise clients may get different
3671          * versions of a resource when navigating the site depending on when the page was cached.
3672          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3673          * an external stylesheet).
3674          *
3675          * @since 1.27
3676          * @param Config $config
3677          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3678          * @return string URL
3679          */
3680         public static function transformResourcePath( Config $config, $path ) {
3681                 global $IP;
3682
3683                 $localDir = $IP;
3684                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3685                 if ( $remotePathPrefix === '' ) {
3686                         // The configured base path is required to be empty string for
3687                         // wikis in the domain root
3688                         $remotePath = '/';
3689                 } else {
3690                         $remotePath = $remotePathPrefix;
3691                 }
3692                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3693                         // - Path is outside wgResourceBasePath, ignore.
3694                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3695                         return $path;
3696                 }
3697                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3698                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3699                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3700                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3701                 $uploadPath = $config->get( 'UploadPath' );
3702                 if ( strpos( $path, $uploadPath ) === 0 ) {
3703                         $localDir = $config->get( 'UploadDirectory' );
3704                         $remotePathPrefix = $remotePath = $uploadPath;
3705                 }
3706
3707                 $path = RelPath::getRelativePath( $path, $remotePath );
3708                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3709         }
3710
3711         /**
3712          * Utility method for transformResourceFilePath().
3713          *
3714          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3715          *
3716          * @since 1.27
3717          * @param string $remotePathPrefix URL path prefix that points to $localPath
3718          * @param string $localPath File directory exposed at $remotePath
3719          * @param string $file Path to target file relative to $localPath
3720          * @return string URL
3721          */
3722         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3723                 $hash = md5_file( "$localPath/$file" );
3724                 if ( $hash === false ) {
3725                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3726                         $hash = '';
3727                 }
3728                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3729         }
3730
3731         /**
3732          * Transform "media" attribute based on request parameters
3733          *
3734          * @param string $media Current value of the "media" attribute
3735          * @return string Modified value of the "media" attribute, or null to skip
3736          * this stylesheet
3737          */
3738         public static function transformCssMedia( $media ) {
3739                 global $wgRequest;
3740
3741                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3742                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3743
3744                 // Switch in on-screen display for media testing
3745                 $switches = [
3746                         'printable' => 'print',
3747                         'handheld' => 'handheld',
3748                 ];
3749                 foreach ( $switches as $switch => $targetMedia ) {
3750                         if ( $wgRequest->getBool( $switch ) ) {
3751                                 if ( $media == $targetMedia ) {
3752                                         $media = '';
3753                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3754                                         /* This regex will not attempt to understand a comma-separated media_query_list
3755                                          *
3756                                          * Example supported values for $media:
3757                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3758                                          * Example NOT supported value for $media:
3759                                          * '3d-glasses, screen, print and resolution > 90dpi'
3760                                          *
3761                                          * If it's a print request, we never want any kind of screen stylesheets
3762                                          * If it's a handheld request (currently the only other choice with a switch),
3763                                          * we don't want simple 'screen' but we might want screen queries that
3764                                          * have a max-width or something, so we'll pass all others on and let the
3765                                          * client do the query.
3766                                          */
3767                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3768                                                 return null;
3769                                         }
3770                                 }
3771                         }
3772                 }
3773
3774                 return $media;
3775         }
3776
3777         /**
3778          * Add a wikitext-formatted message to the output.
3779          * This is equivalent to:
3780          *
3781          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3782          */
3783         public function addWikiMsg( /*...*/ ) {
3784                 $args = func_get_args();
3785                 $name = array_shift( $args );
3786                 $this->addWikiMsgArray( $name, $args );
3787         }
3788
3789         /**
3790          * Add a wikitext-formatted message to the output.
3791          * Like addWikiMsg() except the parameters are taken as an array
3792          * instead of a variable argument list.
3793          *
3794          * @param string $name
3795          * @param array $args
3796          */
3797         public function addWikiMsgArray( $name, $args ) {
3798                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3799         }
3800
3801         /**
3802          * This function takes a number of message/argument specifications, wraps them in
3803          * some overall structure, and then parses the result and adds it to the output.
3804          *
3805          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3806          * and so on. The subsequent arguments may be either
3807          * 1) strings, in which case they are message names, or
3808          * 2) arrays, in which case, within each array, the first element is the message
3809          *    name, and subsequent elements are the parameters to that message.
3810          *
3811          * Don't use this for messages that are not in the user's interface language.
3812          *
3813          * For example:
3814          *
3815          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3816          *
3817          * Is equivalent to:
3818          *
3819          *    $wgOut->addWikiText( "<div class='error'>\n"
3820          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3821          *
3822          * The newline after the opening div is needed in some wikitext. See T21226.
3823          *
3824          * @param string $wrap
3825          */
3826         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3827                 $msgSpecs = func_get_args();
3828                 array_shift( $msgSpecs );
3829                 $msgSpecs = array_values( $msgSpecs );
3830                 $s = $wrap;
3831                 foreach ( $msgSpecs as $n => $spec ) {
3832                         if ( is_array( $spec ) ) {
3833                                 $args = $spec;
3834                                 $name = array_shift( $args );
3835                                 if ( isset( $args['options'] ) ) {
3836                                         unset( $args['options'] );
3837                                         wfDeprecated(
3838                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3839                                                 '1.20'
3840                                         );
3841                                 }
3842                         } else {
3843                                 $args = [];
3844                                 $name = $spec;
3845                         }
3846                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3847                 }
3848                 $this->addWikiText( $s );
3849         }
3850
3851         /**
3852          * Whether the output has a table of contents
3853          * @return bool
3854          * @since 1.22
3855          */
3856         public function isTOCEnabled() {
3857                 return $this->mEnableTOC;
3858         }
3859
3860         /**
3861          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3862          * @param bool $flag
3863          * @since 1.23
3864          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3865          */
3866         public function enableSectionEditLinks( $flag = true ) {
3867                 wfDeprecated( __METHOD__, '1.31' );
3868         }
3869
3870         /**
3871          * @return bool
3872          * @since 1.23
3873          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3874          */
3875         public function sectionEditLinksEnabled() {
3876                 wfDeprecated( __METHOD__, '1.31' );
3877                 return true;
3878         }
3879
3880         /**
3881          * Helper function to setup the PHP implementation of OOUI to use in this request.
3882          *
3883          * @since 1.26
3884          * @param String $skinName The Skin name to determine the correct OOUI theme
3885          * @param String $dir Language direction
3886          */
3887         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
3888                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
3889                 $theme = isset( $themes[$skinName] ) ? $themes[$skinName] : $themes['default'];
3890                 // For example, 'OOUI\WikimediaUITheme'.
3891                 $themeClass = "OOUI\\{$theme}Theme";
3892                 OOUI\Theme::setSingleton( new $themeClass() );
3893                 OOUI\Element::setDefaultDir( $dir );
3894         }
3895
3896         /**
3897          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3898          * MediaWiki and this OutputPage instance.
3899          *
3900          * @since 1.25
3901          */
3902         public function enableOOUI() {
3903                 self::setupOOUI(
3904                         strtolower( $this->getSkin()->getSkinName() ),
3905                         $this->getLanguage()->getDir()
3906                 );
3907                 $this->addModuleStyles( [
3908                         'oojs-ui-core.styles',
3909                         'oojs-ui.styles.indicators',
3910                         'oojs-ui.styles.textures',
3911                         'mediawiki.widgets.styles',
3912                         'oojs-ui.styles.icons-content',
3913                         'oojs-ui.styles.icons-alerts',
3914                         'oojs-ui.styles.icons-interactions',
3915                 ] );
3916         }
3917
3918         /**
3919          * Add Link headers for preloading the wiki's logo.
3920          *
3921          * @since 1.26
3922          */
3923         protected function addLogoPreloadLinkHeaders() {
3924                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
3925
3926                 $tags = [];
3927                 $logosPerDppx = [];
3928                 $logos = [];
3929
3930                 if ( !is_array( $logo ) ) {
3931                         // No media queries required if we only have one variant
3932                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
3933                         return;
3934                 }
3935
3936                 if ( isset( $logo['svg'] ) ) {
3937                         // No media queries required if we only have a 1x and svg variant
3938                         // because all preload-capable browsers support SVGs
3939                         $this->addLinkHeader( '<' . $logo['svg'] . '>;rel=preload;as=image' );
3940                         return;
3941                 }
3942
3943                 foreach ( $logo as $dppx => $src ) {
3944                         // Keys are in this format: "1.5x"
3945                         $dppx = substr( $dppx, 0, -1 );
3946                         $logosPerDppx[$dppx] = $src;
3947                 }
3948
3949                 // Because PHP can't have floats as array keys
3950                 uksort( $logosPerDppx, function ( $a , $b ) {
3951                         $a = floatval( $a );
3952                         $b = floatval( $b );
3953
3954                         if ( $a == $b ) {
3955                                 return 0;
3956                         }
3957                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
3958                         return ( $a < $b ) ? -1 : 1;
3959                 } );
3960
3961                 foreach ( $logosPerDppx as $dppx => $src ) {
3962                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
3963                 }
3964
3965                 $logosCount = count( $logos );
3966                 // Logic must match ResourceLoaderSkinModule:
3967                 // - 1x applies to resolution < 1.5dppx
3968                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
3969                 // - 2x applies to resolution >= 2dppx
3970                 // Note that min-resolution and max-resolution are both inclusive.
3971                 for ( $i = 0; $i < $logosCount; $i++ ) {
3972                         if ( $i === 0 ) {
3973                                 // Smallest dppx
3974                                 // min-resolution is ">=" (larger than or equal to)
3975                                 // "not min-resolution" is essentially "<"
3976                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
3977                         } elseif ( $i !== $logosCount - 1 ) {
3978                                 // In between
3979                                 // Media query expressions can only apply "not" to the entire expression
3980                                 // (e.g. can't express ">= 1.5 and not >= 2).
3981                                 // Workaround: Use <= 1.9999 in place of < 2.
3982                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
3983                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
3984                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
3985                         } else {
3986                                 // Largest dppx
3987                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
3988                         }
3989
3990                         $this->addLinkHeader(
3991                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
3992                         );
3993                 }
3994         }
3995 }