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\Rdbms\IResultWrapper;
  28 use Wikimedia\RelPath;
  29 use Wikimedia\WrappedString;
  30 use Wikimedia\WrappedStringList;
  31
  32 /**
  33  * This class should be covered by a general architecture document which does
  34  * not exist as of January 2011.  This is one of the Core classes and should
  35  * be read at least once by any new developers.
  36  *
  37  * This class is used to prepare the final rendering. A skin is then
  38  * applied to the output parameters (links, javascript, html, categories ...).
  39  *
  40  * @todo FIXME: Another class handles sending the whole page to the client.
  41  *
  42  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  43  * in November 2010.
  44  *
  45  * @todo document
  46  */
  47 class OutputPage extends ContextSource {
  48         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  49         protected $mMetatags = [];
  50
  51         /** @var array */
  52         protected $mLinktags = [];
  53
  54         /** @var bool */
  55         protected $mCanonicalUrl = false;
  56
  57         /**
  58          * @var string The contents of <h1> */
  59         private $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          * @var string The nonce for Content-Security-Policy
 309          */
 310         private $CSPNonce;
 311
 312         /**
 313          * Constructor for OutputPage. This should not be called directly.
 314          * Instead a new RequestContext should be created and it will implicitly create
 315          * a OutputPage tied to that context.
 316          * @param IContextSource $context
 317          */
 318         function __construct( IContextSource $context ) {
 319                 $this->setContext( $context );
 320         }
 321
 322         /**
 323          * Redirect to $url rather than displaying the normal page
 324          *
 325          * @param string $url
 326          * @param string $responsecode HTTP status code
 327          */
 328         public function redirect( $url, $responsecode = '302' ) {
 329                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 330                 $this->mRedirect = str_replace( "\n", '', $url );
 331                 $this->mRedirectCode = $responsecode;
 332         }
 333
 334         /**
 335          * Get the URL to redirect to, or an empty string if not redirect URL set
 336          *
 337          * @return string
 338          */
 339         public function getRedirect() {
 340                 return $this->mRedirect;
 341         }
 342
 343         /**
 344          * Set the copyright URL to send with the output.
 345          * Empty string to omit, null to reset.
 346          *
 347          * @since 1.26
 348          *
 349          * @param string|null $url
 350          */
 351         public function setCopyrightUrl( $url ) {
 352                 $this->copyrightUrl = $url;
 353         }
 354
 355         /**
 356          * Set the HTTP status code to send with the output.
 357          *
 358          * @param int $statusCode
 359          */
 360         public function setStatusCode( $statusCode ) {
 361                 $this->mStatusCode = $statusCode;
 362         }
 363
 364         /**
 365          * Add a new "<meta>" tag
 366          * To add an http-equiv meta tag, precede the name with "http:"
 367          *
 368          * @param string $name Name of the meta tag
 369          * @param string $val Value of the meta tag
 370          */
 371         function addMeta( $name, $val ) {
 372                 array_push( $this->mMetatags, [ $name, $val ] );
 373         }
 374
 375         /**
 376          * Returns the current <meta> tags
 377          *
 378          * @since 1.25
 379          * @return array
 380          */
 381         public function getMetaTags() {
 382                 return $this->mMetatags;
 383         }
 384
 385         /**
 386          * Add a new \<link\> tag to the page header.
 387          *
 388          * Note: use setCanonicalUrl() for rel=canonical.
 389          *
 390          * @param array $linkarr Associative array of attributes.
 391          */
 392         function addLink( array $linkarr ) {
 393                 array_push( $this->mLinktags, $linkarr );
 394         }
 395
 396         /**
 397          * Returns the current <link> tags
 398          *
 399          * @since 1.25
 400          * @return array
 401          */
 402         public function getLinkTags() {
 403                 return $this->mLinktags;
 404         }
 405
 406         /**
 407          * Set the URL to be used for the <link rel=canonical>. This should be used
 408          * in preference to addLink(), to avoid duplicate link tags.
 409          * @param string $url
 410          */
 411         function setCanonicalUrl( $url ) {
 412                 $this->mCanonicalUrl = $url;
 413         }
 414
 415         /**
 416          * Returns the URL to be used for the <link rel=canonical> if
 417          * one is set.
 418          *
 419          * @since 1.25
 420          * @return bool|string
 421          */
 422         public function getCanonicalUrl() {
 423                 return $this->mCanonicalUrl;
 424         }
 425
 426         /**
 427          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 428          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 429          * if possible.
 430          *
 431          * @param string $script Raw HTML
 432          */
 433         function addScript( $script ) {
 434                 $this->mScripts .= $script;
 435         }
 436
 437         /**
 438          * Add a JavaScript file to be loaded as `<script>` on this page.
 439          *
 440          * Internal use only. Use OutputPage::addModules() if possible.
 441          *
 442          * @param string $file URL to file (absolute path, protocol-relative, or full url)
 443          * @param string|null $unused Previously used to change the cache-busting query parameter
 444          */
 445         public function addScriptFile( $file, $unused = null ) {
 446                 if ( substr( $file, 0, 1 ) !== '/' && !preg_match( '#^[a-z]*://#i', $file ) ) {
 447                         // This is not an absolute path, protocol-relative url, or full scheme url,
 448                         // presumed to be an old call intended to include a file from /w/skins/common,
 449                         // which doesn't exist anymore as of MediaWiki 1.24 per T71277. Ignore.
 450                         wfDeprecated( __METHOD__, '1.24' );
 451                         return;
 452                 }
 453                 $this->addScript( Html::linkedScript( $file, $this->getCSPNonce() ) );
 454         }
 455
 456         /**
 457          * Add a self-contained script tag with the given contents
 458          * Internal use only. Use OutputPage::addModules() if possible.
 459          *
 460          * @param string $script JavaScript text, no script tags
 461          */
 462         public function addInlineScript( $script ) {
 463                 $this->mScripts .= Html::inlineScript( "\n$script\n", $this->getCSPNonce() ) . "\n";
 464         }
 465
 466         /**
 467          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 468          * which are no longer registered (eg a page is cached before an extension is disabled)
 469          * @param array $modules
 470          * @param string|null $position Unused
 471          * @param string $type
 472          * @return array
 473          */
 474         protected function filterModules( array $modules, $position = null,
 475                 $type = ResourceLoaderModule::TYPE_COMBINED
 476         ) {
 477                 $resourceLoader = $this->getResourceLoader();
 478                 $filteredModules = [];
 479                 foreach ( $modules as $val ) {
 480                         $module = $resourceLoader->getModule( $val );
 481                         if ( $module instanceof ResourceLoaderModule
 482                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 483                         ) {
 484                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 485                                         $this->warnModuleTargetFilter( $module->getName() );
 486                                         continue;
 487                                 }
 488                                 $filteredModules[] = $val;
 489                         }
 490                 }
 491                 return $filteredModules;
 492         }
 493
 494         private function warnModuleTargetFilter( $moduleName ) {
 495                 static $warnings = [];
 496                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 497                         return;
 498                 }
 499                 $warnings[$this->mTarget][$moduleName] = true;
 500                 $this->getResourceLoader()->getLogger()->debug(
 501                         'Module "{module}" not loadable on target "{target}".',
 502                         [
 503                                 'module' => $moduleName,
 504                                 'target' => $this->mTarget,
 505                         ]
 506                 );
 507         }
 508
 509         /**
 510          * Get the list of modules to include on this page
 511          *
 512          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 513          * @param string|null $position Unused
 514          * @param string $param
 515          * @param string $type
 516          * @return array Array of module names
 517          */
 518         public function getModules( $filter = false, $position = null, $param = 'mModules',
 519                 $type = ResourceLoaderModule::TYPE_COMBINED
 520         ) {
 521                 $modules = array_values( array_unique( $this->$param ) );
 522                 return $filter
 523                         ? $this->filterModules( $modules, null, $type )
 524                         : $modules;
 525         }
 526
 527         /**
 528          * Load one or more ResourceLoader modules on this page.
 529          *
 530          * @param string|array $modules Module name (string) or array of module names
 531          */
 532         public function addModules( $modules ) {
 533                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 534         }
 535
 536         /**
 537          * Get the list of script-only modules to load on this page.
 538          *
 539          * @param bool $filter
 540          * @param string|null $position Unused
 541          * @return array Array of module names
 542          */
 543         public function getModuleScripts( $filter = false, $position = null ) {
 544                 return $this->getModules( $filter, null, 'mModuleScripts',
 545                         ResourceLoaderModule::TYPE_SCRIPTS
 546                 );
 547         }
 548
 549         /**
 550          * Load the scripts of one or more ResourceLoader modules, on this page.
 551          *
 552          * This method exists purely to provide the legacy behaviour of loading
 553          * a module's scripts in the global scope, and without dependency resolution.
 554          * See <https://phabricator.wikimedia.org/T188689>.
 555          *
 556          * @deprecated since 1.31 Use addModules() instead.
 557          * @param string|array $modules Module name (string) or array of module names
 558          */
 559         public function addModuleScripts( $modules ) {
 560                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 561         }
 562
 563         /**
 564          * Get the list of style-only modules to load on this page.
 565          *
 566          * @param bool $filter
 567          * @param string|null $position Unused
 568          * @return array Array of module names
 569          */
 570         public function getModuleStyles( $filter = false, $position = null ) {
 571                 return $this->getModules( $filter, null, 'mModuleStyles',
 572                         ResourceLoaderModule::TYPE_STYLES
 573                 );
 574         }
 575
 576         /**
 577          * Load the styles of one or more ResourceLoader modules on this page.
 578          *
 579          * Module styles added through this function will be loaded as a stylesheet,
 580          * using a standard `<link rel=stylesheet>` HTML tag, rather than as a combined
 581          * Javascript and CSS package. Thus, they will even load when JavaScript is disabled.
 582          *
 583          * @param string|array $modules Module name (string) or array of module names
 584          */
 585         public function addModuleStyles( $modules ) {
 586                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 587         }
 588
 589         /**
 590          * @return null|string ResourceLoader target
 591          */
 592         public function getTarget() {
 593                 return $this->mTarget;
 594         }
 595
 596         /**
 597          * Sets ResourceLoader target for load.php links. If null, will be omitted
 598          *
 599          * @param string|null $target
 600          */
 601         public function setTarget( $target ) {
 602                 $this->mTarget = $target;
 603         }
 604
 605         /**
 606          * Add a mapping from a LinkTarget to a Content, for things like page preview.
 607          * @see self::addContentOverrideCallback()
 608          * @since 1.32
 609          * @param LinkTarget $target
 610          * @param Content $content
 611          */
 612         public function addContentOverride( LinkTarget $target, Content $content ) {
 613                 if ( !$this->contentOverrides ) {
 614                         // Register a callback for $this->contentOverrides on the first call
 615                         $this->addContentOverrideCallback( function ( LinkTarget $target ) {
 616                                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 617                                 return $this->contentOverrides[$key] ?? null;
 618                         } );
 619                 }
 620
 621                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 622                 $this->contentOverrides[$key] = $content;
 623         }
 624
 625         /**
 626          * Add a callback for mapping from a Title to a Content object, for things
 627          * like page preview.
 628          * @see ResourceLoaderContext::getContentOverrideCallback()
 629          * @since 1.32
 630          * @param callable $callback
 631          */
 632         public function addContentOverrideCallback( callable $callback ) {
 633                 $this->contentOverrideCallbacks[] = $callback;
 634         }
 635
 636         /**
 637          * Get an array of head items
 638          *
 639          * @return array
 640          */
 641         function getHeadItemsArray() {
 642                 return $this->mHeadItems;
 643         }
 644
 645         /**
 646          * Add or replace a head item to the output
 647          *
 648          * Whenever possible, use more specific options like ResourceLoader modules,
 649          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 650          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 651          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 652          * This would be your very LAST fallback.
 653          *
 654          * @param string $name Item name
 655          * @param string $value Raw HTML
 656          */
 657         public function addHeadItem( $name, $value ) {
 658                 $this->mHeadItems[$name] = $value;
 659         }
 660
 661         /**
 662          * Add one or more head items to the output
 663          *
 664          * @since 1.28
 665          * @param string|string[] $values Raw HTML
 666          */
 667         public function addHeadItems( $values ) {
 668                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 669         }
 670
 671         /**
 672          * Check if the header item $name is already set
 673          *
 674          * @param string $name Item name
 675          * @return bool
 676          */
 677         public function hasHeadItem( $name ) {
 678                 return isset( $this->mHeadItems[$name] );
 679         }
 680
 681         /**
 682          * Add a class to the <body> element
 683          *
 684          * @since 1.30
 685          * @param string|string[] $classes One or more classes to add
 686          */
 687         public function addBodyClasses( $classes ) {
 688                 $this->mAdditionalBodyClasses = array_merge( $this->mAdditionalBodyClasses, (array)$classes );
 689         }
 690
 691         /**
 692          * Set whether the output should only contain the body of the article,
 693          * without any skin, sidebar, etc.
 694          * Used e.g. when calling with "action=render".
 695          *
 696          * @param bool $only Whether to output only the body of the article
 697          */
 698         public function setArticleBodyOnly( $only ) {
 699                 $this->mArticleBodyOnly = $only;
 700         }
 701
 702         /**
 703          * Return whether the output will contain only the body of the article
 704          *
 705          * @return bool
 706          */
 707         public function getArticleBodyOnly() {
 708                 return $this->mArticleBodyOnly;
 709         }
 710
 711         /**
 712          * Set an additional output property
 713          * @since 1.21
 714          *
 715          * @param string $name
 716          * @param mixed $value
 717          */
 718         public function setProperty( $name, $value ) {
 719                 $this->mProperties[$name] = $value;
 720         }
 721
 722         /**
 723          * Get an additional output property
 724          * @since 1.21
 725          *
 726          * @param string $name
 727          * @return mixed Property value or null if not found
 728          */
 729         public function getProperty( $name ) {
 730                 return $this->mProperties[$name] ?? null;
 731         }
 732
 733         /**
 734          * checkLastModified tells the client to use the client-cached page if
 735          * possible. If successful, the OutputPage is disabled so that
 736          * any future call to OutputPage->output() have no effect.
 737          *
 738          * Side effect: sets mLastModified for Last-Modified header
 739          *
 740          * @param string $timestamp
 741          *
 742          * @return bool True if cache-ok headers was sent.
 743          */
 744         public function checkLastModified( $timestamp ) {
 745                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 746                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 747                         return false;
 748                 }
 749                 $config = $this->getConfig();
 750                 if ( !$config->get( 'CachePages' ) ) {
 751                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 752                         return false;
 753                 }
 754
 755                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 756                 $modifiedTimes = [
 757                         'page' => $timestamp,
 758                         'user' => $this->getUser()->getTouched(),
 759                         'epoch' => $config->get( 'CacheEpoch' )
 760                 ];
 761                 if ( $config->get( 'UseSquid' ) ) {
 762                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, $this->getCdnCacheEpoch(
 763                                 time(),
 764                                 $config->get( 'SquidMaxage' )
 765                         ) );
 766                 }
 767                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 768
 769                 $maxModified = max( $modifiedTimes );
 770                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 771
 772                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 773                 if ( $clientHeader === false ) {
 774                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 775                         return false;
 776                 }
 777
 778                 # IE sends sizes after the date like this:
 779                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 780                 # this breaks strtotime().
 781                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 782
 783                 Wikimedia\suppressWarnings(); // E_STRICT system time bitching
 784                 $clientHeaderTime = strtotime( $clientHeader );
 785                 Wikimedia\restoreWarnings();
 786                 if ( !$clientHeaderTime ) {
 787                         wfDebug( __METHOD__
 788                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 789                         return false;
 790                 }
 791                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 792
 793                 # Make debug info
 794                 $info = '';
 795                 foreach ( $modifiedTimes as $name => $value ) {
 796                         if ( $info !== '' ) {
 797                                 $info .= ', ';
 798                         }
 799                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 800                 }
 801
 802                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 803                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 804                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 805                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 806                 if ( $clientHeaderTime < $maxModified ) {
 807                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 808                         return false;
 809                 }
 810
 811                 # Not modified
 812                 # Give a 304 Not Modified response code and disable body output
 813                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 814                 ini_set( 'zlib.output_compression', 0 );
 815                 $this->getRequest()->response()->statusHeader( 304 );
 816                 $this->sendCacheControl();
 817                 $this->disable();
 818
 819                 // Don't output a compressed blob when using ob_gzhandler;
 820                 // it's technically against HTTP spec and seems to confuse
 821                 // Firefox when the response gets split over two packets.
 822                 wfClearOutputBuffers();
 823
 824                 return true;
 825         }
 826
 827         /**
 828          * @param int $reqTime Time of request (eg. now)
 829          * @param int $maxAge Cache TTL in seconds
 830          * @return int Timestamp
 831          */
 832         private function getCdnCacheEpoch( $reqTime, $maxAge ) {
 833                 // Ensure Last-Modified is never more than (wgSquidMaxage) in the past,
 834                 // because even if the wiki page content hasn't changed since, static
 835                 // resources may have changed (skin HTML, interface messages, urls, etc.)
 836                 // and must roll-over in a timely manner (T46570)
 837                 return $reqTime - $maxAge;
 838         }
 839
 840         /**
 841          * Override the last modified timestamp
 842          *
 843          * @param string $timestamp New timestamp, in a format readable by
 844          *        wfTimestamp()
 845          */
 846         public function setLastModified( $timestamp ) {
 847                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 848         }
 849
 850         /**
 851          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 852          *
 853          * @param string $policy The literal string to output as the contents of
 854          *   the meta tag.  Will be parsed according to the spec and output in
 855          *   standardized form.
 856          * @return null
 857          */
 858         public function setRobotPolicy( $policy ) {
 859                 $policy = Article::formatRobotPolicy( $policy );
 860
 861                 if ( isset( $policy['index'] ) ) {
 862                         $this->setIndexPolicy( $policy['index'] );
 863                 }
 864                 if ( isset( $policy['follow'] ) ) {
 865                         $this->setFollowPolicy( $policy['follow'] );
 866                 }
 867         }
 868
 869         /**
 870          * Set the index policy for the page, but leave the follow policy un-
 871          * touched.
 872          *
 873          * @param string $policy Either 'index' or 'noindex'.
 874          * @return null
 875          */
 876         public function setIndexPolicy( $policy ) {
 877                 $policy = trim( $policy );
 878                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 879                         $this->mIndexPolicy = $policy;
 880                 }
 881         }
 882
 883         /**
 884          * Set the follow policy for the page, but leave the index policy un-
 885          * touched.
 886          *
 887          * @param string $policy Either 'follow' or 'nofollow'.
 888          * @return null
 889          */
 890         public function setFollowPolicy( $policy ) {
 891                 $policy = trim( $policy );
 892                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 893                         $this->mFollowPolicy = $policy;
 894                 }
 895         }
 896
 897         /**
 898          * Set the new value of the "action text", this will be added to the
 899          * "HTML title", separated from it with " - ".
 900          *
 901          * @param string $text New value of the "action text"
 902          */
 903         public function setPageTitleActionText( $text ) {
 904                 $this->mPageTitleActionText = $text;
 905         }
 906
 907         /**
 908          * Get the value of the "action text"
 909          *
 910          * @return string
 911          */
 912         public function getPageTitleActionText() {
 913                 return $this->mPageTitleActionText;
 914         }
 915
 916         /**
 917          * "HTML title" means the contents of "<title>".
 918          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 919          *
 920          * @param string|Message $name
 921          */
 922         public function setHTMLTitle( $name ) {
 923                 if ( $name instanceof Message ) {
 924                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 925                 } else {
 926                         $this->mHTMLtitle = $name;
 927                 }
 928         }
 929
 930         /**
 931          * Return the "HTML title", i.e. the content of the "<title>" tag.
 932          *
 933          * @return string
 934          */
 935         public function getHTMLTitle() {
 936                 return $this->mHTMLtitle;
 937         }
 938
 939         /**
 940          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 941          *
 942          * @param Title $t
 943          */
 944         public function setRedirectedFrom( $t ) {
 945                 $this->mRedirectedFrom = $t;
 946         }
 947
 948         /**
 949          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 950          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 951          * but not bad tags like \<script\>. This function automatically sets
 952          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 953          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 954          * good tags like \<i\> will be dropped entirely.
 955          *
 956          * @param string|Message $name
 957          */
 958         public function setPageTitle( $name ) {
 959                 if ( $name instanceof Message ) {
 960                         $name = $name->setContext( $this->getContext() )->text();
 961                 }
 962
 963                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 964                 # but leave "<i>foobar</i>" alone
 965                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 966                 $this->mPageTitle = $nameWithTags;
 967
 968                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 969                 $this->setHTMLTitle(
 970                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 971                                 ->inContentLanguage()
 972                 );
 973         }
 974
 975         /**
 976          * Return the "page title", i.e. the content of the \<h1\> tag.
 977          *
 978          * @return string
 979          */
 980         public function getPageTitle() {
 981                 return $this->mPageTitle;
 982         }
 983
 984         /**
 985          * Set the Title object to use
 986          *
 987          * @param Title $t
 988          */
 989         public function setTitle( Title $t ) {
 990                 $this->getContext()->setTitle( $t );
 991         }
 992
 993         /**
 994          * Replace the subtitle with $str
 995          *
 996          * @param string|Message $str New value of the subtitle. String should be safe HTML.
 997          */
 998         public function setSubtitle( $str ) {
 999                 $this->clearSubtitle();
1000                 $this->addSubtitle( $str );
1001         }
1002
1003         /**
1004          * Add $str to the subtitle
1005          *
1006          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
1007          */
1008         public function addSubtitle( $str ) {
1009                 if ( $str instanceof Message ) {
1010                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
1011                 } else {
1012                         $this->mSubtitle[] = $str;
1013                 }
1014         }
1015
1016         /**
1017          * Build message object for a subtitle containing a backlink to a page
1018          *
1019          * @param Title $title Title to link to
1020          * @param array $query Array of additional parameters to include in the link
1021          * @return Message
1022          * @since 1.25
1023          */
1024         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1025                 if ( $title->isRedirect() ) {
1026                         $query['redirect'] = 'no';
1027                 }
1028                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1029                 return wfMessage( 'backlinksubtitle' )
1030                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1031         }
1032
1033         /**
1034          * Add a subtitle containing a backlink to a page
1035          *
1036          * @param Title $title Title to link to
1037          * @param array $query Array of additional parameters to include in the link
1038          */
1039         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1040                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1041         }
1042
1043         /**
1044          * Clear the subtitles
1045          */
1046         public function clearSubtitle() {
1047                 $this->mSubtitle = [];
1048         }
1049
1050         /**
1051          * Get the subtitle
1052          *
1053          * @return string
1054          */
1055         public function getSubtitle() {
1056                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1057         }
1058
1059         /**
1060          * Set the page as printable, i.e. it'll be displayed with all
1061          * print styles included
1062          */
1063         public function setPrintable() {
1064                 $this->mPrintable = true;
1065         }
1066
1067         /**
1068          * Return whether the page is "printable"
1069          *
1070          * @return bool
1071          */
1072         public function isPrintable() {
1073                 return $this->mPrintable;
1074         }
1075
1076         /**
1077          * Disable output completely, i.e. calling output() will have no effect
1078          */
1079         public function disable() {
1080                 $this->mDoNothing = true;
1081         }
1082
1083         /**
1084          * Return whether the output will be completely disabled
1085          *
1086          * @return bool
1087          */
1088         public function isDisabled() {
1089                 return $this->mDoNothing;
1090         }
1091
1092         /**
1093          * Show an "add new section" link?
1094          *
1095          * @return bool
1096          */
1097         public function showNewSectionLink() {
1098                 return $this->mNewSectionLink;
1099         }
1100
1101         /**
1102          * Forcibly hide the new section link?
1103          *
1104          * @return bool
1105          */
1106         public function forceHideNewSectionLink() {
1107                 return $this->mHideNewSectionLink;
1108         }
1109
1110         /**
1111          * Add or remove feed links in the page header
1112          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1113          * for the new version
1114          * @see addFeedLink()
1115          *
1116          * @param bool $show True: add default feeds, false: remove all feeds
1117          */
1118         public function setSyndicated( $show = true ) {
1119                 if ( $show ) {
1120                         $this->setFeedAppendQuery( false );
1121                 } else {
1122                         $this->mFeedLinks = [];
1123                 }
1124         }
1125
1126         /**
1127          * Add default feeds to the page header
1128          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1129          * for the new version
1130          * @see addFeedLink()
1131          *
1132          * @param string $val Query to append to feed links or false to output
1133          *        default links
1134          */
1135         public function setFeedAppendQuery( $val ) {
1136                 $this->mFeedLinks = [];
1137
1138                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1139                         $query = "feed=$type";
1140                         if ( is_string( $val ) ) {
1141                                 $query .= '&' . $val;
1142                         }
1143                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1144                 }
1145         }
1146
1147         /**
1148          * Add a feed link to the page header
1149          *
1150          * @param string $format Feed type, should be a key of $wgFeedClasses
1151          * @param string $href URL
1152          */
1153         public function addFeedLink( $format, $href ) {
1154                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1155                         $this->mFeedLinks[$format] = $href;
1156                 }
1157         }
1158
1159         /**
1160          * Should we output feed links for this page?
1161          * @return bool
1162          */
1163         public function isSyndicated() {
1164                 return count( $this->mFeedLinks ) > 0;
1165         }
1166
1167         /**
1168          * Return URLs for each supported syndication format for this page.
1169          * @return array Associating format keys with URLs
1170          */
1171         public function getSyndicationLinks() {
1172                 return $this->mFeedLinks;
1173         }
1174
1175         /**
1176          * Will currently always return null
1177          *
1178          * @return null
1179          */
1180         public function getFeedAppendQuery() {
1181                 return $this->mFeedLinksAppendQuery;
1182         }
1183
1184         /**
1185          * Set whether the displayed content is related to the source of the
1186          * corresponding article on the wiki
1187          * Setting true will cause the change "article related" toggle to true
1188          *
1189          * @param bool $v
1190          */
1191         public function setArticleFlag( $v ) {
1192                 $this->mIsarticle = $v;
1193                 if ( $v ) {
1194                         $this->mIsArticleRelated = $v;
1195                 }
1196         }
1197
1198         /**
1199          * Return whether the content displayed page is related to the source of
1200          * the corresponding article on the wiki
1201          *
1202          * @return bool
1203          */
1204         public function isArticle() {
1205                 return $this->mIsarticle;
1206         }
1207
1208         /**
1209          * Set whether this page is related an article on the wiki
1210          * Setting false will cause the change of "article flag" toggle to false
1211          *
1212          * @param bool $v
1213          */
1214         public function setArticleRelated( $v ) {
1215                 $this->mIsArticleRelated = $v;
1216                 if ( !$v ) {
1217                         $this->mIsarticle = false;
1218                 }
1219         }
1220
1221         /**
1222          * Return whether this page is related an article on the wiki
1223          *
1224          * @return bool
1225          */
1226         public function isArticleRelated() {
1227                 return $this->mIsArticleRelated;
1228         }
1229
1230         /**
1231          * Add new language links
1232          *
1233          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1234          *                               (e.g. 'fr:Test page')
1235          */
1236         public function addLanguageLinks( array $newLinkArray ) {
1237                 $this->mLanguageLinks += $newLinkArray;
1238         }
1239
1240         /**
1241          * Reset the language links and add new language links
1242          *
1243          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1244          *                               (e.g. 'fr:Test page')
1245          */
1246         public function setLanguageLinks( array $newLinkArray ) {
1247                 $this->mLanguageLinks = $newLinkArray;
1248         }
1249
1250         /**
1251          * Get the list of language links
1252          *
1253          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1254          */
1255         public function getLanguageLinks() {
1256                 return $this->mLanguageLinks;
1257         }
1258
1259         /**
1260          * Add an array of categories, with names in the keys
1261          *
1262          * @param array $categories Mapping category name => sort key
1263          */
1264         public function addCategoryLinks( array $categories ) {
1265                 global $wgContLang;
1266
1267                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1268                         return;
1269                 }
1270
1271                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1272
1273                 # Set all the values to 'normal'.
1274                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1275
1276                 # Mark hidden categories
1277                 foreach ( $res as $row ) {
1278                         if ( isset( $row->pp_value ) ) {
1279                                 $categories[$row->page_title] = 'hidden';
1280                         }
1281                 }
1282
1283                 // Avoid PHP 7.1 warning of passing $this by reference
1284                 $outputPage = $this;
1285                 # Add the remaining categories to the skin
1286                 if ( Hooks::run(
1287                         'OutputPageMakeCategoryLinks',
1288                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1289                 ) {
1290                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1291                         foreach ( $categories as $category => $type ) {
1292                                 // array keys will cast numeric category names to ints, so cast back to string
1293                                 $category = (string)$category;
1294                                 $origcategory = $category;
1295                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1296                                 if ( !$title ) {
1297                                         continue;
1298                                 }
1299                                 $wgContLang->findVariantLink( $category, $title, true );
1300                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1301                                         continue;
1302                                 }
1303                                 $text = $wgContLang->convertHtml( $title->getText() );
1304                                 $this->mCategories[$type][] = $title->getText();
1305                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1306                         }
1307                 }
1308         }
1309
1310         /**
1311          * @param array $categories
1312          * @return bool|IResultWrapper
1313          */
1314         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1315                 # Add the links to a LinkBatch
1316                 $arr = [ NS_CATEGORY => $categories ];
1317                 $lb = new LinkBatch;
1318                 $lb->setArray( $arr );
1319
1320                 # Fetch existence plus the hiddencat property
1321                 $dbr = wfGetDB( DB_REPLICA );
1322                 $fields = array_merge(
1323                         LinkCache::getSelectFields(),
1324                         [ 'page_namespace', 'page_title', 'pp_value' ]
1325                 );
1326
1327                 $res = $dbr->select( [ 'page', 'page_props' ],
1328                         $fields,
1329                         $lb->constructSet( 'page', $dbr ),
1330                         __METHOD__,
1331                         [],
1332                         [ 'page_props' => [ 'LEFT JOIN', [
1333                                 'pp_propname' => 'hiddencat',
1334                                 'pp_page = page_id'
1335                         ] ] ]
1336                 );
1337
1338                 # Add the results to the link cache
1339                 $linkCache = MediaWikiServices::getInstance()->getLinkCache();
1340                 $lb->addResultToCache( $linkCache, $res );
1341
1342                 return $res;
1343         }
1344
1345         /**
1346          * Reset the category links (but not the category list) and add $categories
1347          *
1348          * @param array $categories Mapping category name => sort key
1349          */
1350         public function setCategoryLinks( array $categories ) {
1351                 $this->mCategoryLinks = [];
1352                 $this->addCategoryLinks( $categories );
1353         }
1354
1355         /**
1356          * Get the list of category links, in a 2-D array with the following format:
1357          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1358          * hidden categories) and $link a HTML fragment with a link to the category
1359          * page
1360          *
1361          * @return array
1362          */
1363         public function getCategoryLinks() {
1364                 return $this->mCategoryLinks;
1365         }
1366
1367         /**
1368          * Get the list of category names this page belongs to.
1369          *
1370          * @param string $type The type of categories which should be returned. Possible values:
1371          *  * all: all categories of all types
1372          *  * hidden: only the hidden categories
1373          *  * normal: all categories, except hidden categories
1374          * @return array Array of strings
1375          */
1376         public function getCategories( $type = 'all' ) {
1377                 if ( $type === 'all' ) {
1378                         $allCategories = [];
1379                         foreach ( $this->mCategories as $categories ) {
1380                                 $allCategories = array_merge( $allCategories, $categories );
1381                         }
1382                         return $allCategories;
1383                 }
1384                 if ( !isset( $this->mCategories[$type] ) ) {
1385                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1386                 }
1387                 return $this->mCategories[$type];
1388         }
1389
1390         /**
1391          * Add an array of indicators, with their identifiers as array
1392          * keys and HTML contents as values.
1393          *
1394          * In case of duplicate keys, existing values are overwritten.
1395          *
1396          * @param array $indicators
1397          * @since 1.25
1398          */
1399         public function setIndicators( array $indicators ) {
1400                 $this->mIndicators = $indicators + $this->mIndicators;
1401                 // Keep ordered by key
1402                 ksort( $this->mIndicators );
1403         }
1404
1405         /**
1406          * Get the indicators associated with this page.
1407          *
1408          * The array will be internally ordered by item keys.
1409          *
1410          * @return array Keys: identifiers, values: HTML contents
1411          * @since 1.25
1412          */
1413         public function getIndicators() {
1414                 return $this->mIndicators;
1415         }
1416
1417         /**
1418          * Adds help link with an icon via page indicators.
1419          * Link target can be overridden by a local message containing a wikilink:
1420          * the message key is: lowercase action or special page name + '-helppage'.
1421          * @param string $to Target MediaWiki.org page title or encoded URL.
1422          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1423          * @since 1.25
1424          */
1425         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1426                 $this->addModuleStyles( 'mediawiki.helplink' );
1427                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1428
1429                 if ( $overrideBaseUrl ) {
1430                         $helpUrl = $to;
1431                 } else {
1432                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1433                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1434                 }
1435
1436                 $link = Html::rawElement(
1437                         'a',
1438                         [
1439                                 'href' => $helpUrl,
1440                                 'target' => '_blank',
1441                                 'class' => 'mw-helplink',
1442                         ],
1443                         $text
1444                 );
1445
1446                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1447         }
1448
1449         /**
1450          * Do not allow scripts which can be modified by wiki users to load on this page;
1451          * only allow scripts bundled with, or generated by, the software.
1452          * Site-wide styles are controlled by a config setting, since they can be
1453          * used to create a custom skin/theme, but not user-specific ones.
1454          *
1455          * @todo this should be given a more accurate name
1456          */
1457         public function disallowUserJs() {
1458                 $this->reduceAllowedModules(
1459                         ResourceLoaderModule::TYPE_SCRIPTS,
1460                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1461                 );
1462
1463                 // Site-wide styles are controlled by a config setting, see T73621
1464                 // for background on why. User styles are never allowed.
1465                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1466                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1467                 } else {
1468                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1469                 }
1470                 $this->reduceAllowedModules(
1471                         ResourceLoaderModule::TYPE_STYLES,
1472                         $styleOrigin
1473                 );
1474         }
1475
1476         /**
1477          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1478          * @see ResourceLoaderModule::$origin
1479          * @param string $type ResourceLoaderModule TYPE_ constant
1480          * @return int ResourceLoaderModule ORIGIN_ class constant
1481          */
1482         public function getAllowedModules( $type ) {
1483                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1484                         return min( array_values( $this->mAllowedModules ) );
1485                 } else {
1486                         return $this->mAllowedModules[$type] ?? ResourceLoaderModule::ORIGIN_ALL;
1487                 }
1488         }
1489
1490         /**
1491          * Limit the highest level of CSS/JS untrustworthiness allowed.
1492          *
1493          * If passed the same or a higher level than the current level of untrustworthiness set, the
1494          * level will remain unchanged.
1495          *
1496          * @param string $type
1497          * @param int $level ResourceLoaderModule class constant
1498          */
1499         public function reduceAllowedModules( $type, $level ) {
1500                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1501         }
1502
1503         /**
1504          * Prepend $text to the body HTML
1505          *
1506          * @param string $text HTML
1507          */
1508         public function prependHTML( $text ) {
1509                 $this->mBodytext = $text . $this->mBodytext;
1510         }
1511
1512         /**
1513          * Append $text to the body HTML
1514          *
1515          * @param string $text HTML
1516          */
1517         public function addHTML( $text ) {
1518                 $this->mBodytext .= $text;
1519         }
1520
1521         /**
1522          * Shortcut for adding an Html::element via addHTML.
1523          *
1524          * @since 1.19
1525          *
1526          * @param string $element
1527          * @param array $attribs
1528          * @param string $contents
1529          */
1530         public function addElement( $element, array $attribs = [], $contents = '' ) {
1531                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1532         }
1533
1534         /**
1535          * Clear the body HTML
1536          */
1537         public function clearHTML() {
1538                 $this->mBodytext = '';
1539         }
1540
1541         /**
1542          * Get the body HTML
1543          *
1544          * @return string HTML
1545          */
1546         public function getHTML() {
1547                 return $this->mBodytext;
1548         }
1549
1550         /**
1551          * Get/set the ParserOptions object to use for wikitext parsing
1552          *
1553          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1554          *   current ParserOption object. This parameter is deprecated since 1.31.
1555          * @return ParserOptions
1556          */
1557         public function parserOptions( $options = null ) {
1558                 if ( $options !== null ) {
1559                         wfDeprecated( __METHOD__ . ' with non-null $options', '1.31' );
1560                 }
1561
1562                 if ( $options !== null && !empty( $options->isBogus ) ) {
1563                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1564                         // been changed somehow, and keep it if so.
1565                         $anonPO = ParserOptions::newFromAnon();
1566                         $anonPO->setAllowUnsafeRawHtml( false );
1567                         if ( !$options->matches( $anonPO ) ) {
1568                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1569                                 $options->isBogus = false;
1570                         }
1571                 }
1572
1573                 if ( !$this->mParserOptions ) {
1574                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1575                                 // $wgUser isn't unstubbable yet, so don't try to get a
1576                                 // ParserOptions for it. And don't cache this ParserOptions
1577                                 // either.
1578                                 $po = ParserOptions::newFromAnon();
1579                                 $po->setAllowUnsafeRawHtml( false );
1580                                 $po->isBogus = true;
1581                                 if ( $options !== null ) {
1582                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1583                                 }
1584                                 return $po;
1585                         }
1586
1587                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1588                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1589                 }
1590
1591                 if ( $options !== null && !empty( $options->isBogus ) ) {
1592                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1593                         // thing.
1594                         return wfSetVar( $this->mParserOptions, null, true );
1595                 } else {
1596                         return wfSetVar( $this->mParserOptions, $options );
1597                 }
1598         }
1599
1600         /**
1601          * Set the revision ID which will be seen by the wiki text parser
1602          * for things such as embedded {{REVISIONID}} variable use.
1603          *
1604          * @param int|null $revid An positive integer, or null
1605          * @return mixed Previous value
1606          */
1607         public function setRevisionId( $revid ) {
1608                 $val = is_null( $revid ) ? null : intval( $revid );
1609                 return wfSetVar( $this->mRevisionId, $val );
1610         }
1611
1612         /**
1613          * Get the displayed revision ID
1614          *
1615          * @return int
1616          */
1617         public function getRevisionId() {
1618                 return $this->mRevisionId;
1619         }
1620
1621         /**
1622          * Set the timestamp of the revision which will be displayed. This is used
1623          * to avoid a extra DB call in Skin::lastModified().
1624          *
1625          * @param string|null $timestamp
1626          * @return mixed Previous value
1627          */
1628         public function setRevisionTimestamp( $timestamp ) {
1629                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1630         }
1631
1632         /**
1633          * Get the timestamp of displayed revision.
1634          * This will be null if not filled by setRevisionTimestamp().
1635          *
1636          * @return string|null
1637          */
1638         public function getRevisionTimestamp() {
1639                 return $this->mRevisionTimestamp;
1640         }
1641
1642         /**
1643          * Set the displayed file version
1644          *
1645          * @param File|bool $file
1646          * @return mixed Previous value
1647          */
1648         public function setFileVersion( $file ) {
1649                 $val = null;
1650                 if ( $file instanceof File && $file->exists() ) {
1651                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1652                 }
1653                 return wfSetVar( $this->mFileVersion, $val, true );
1654         }
1655
1656         /**
1657          * Get the displayed file version
1658          *
1659          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1660          */
1661         public function getFileVersion() {
1662                 return $this->mFileVersion;
1663         }
1664
1665         /**
1666          * Get the templates used on this page
1667          *
1668          * @return array (namespace => dbKey => revId)
1669          * @since 1.18
1670          */
1671         public function getTemplateIds() {
1672                 return $this->mTemplateIds;
1673         }
1674
1675         /**
1676          * Get the files used on this page
1677          *
1678          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1679          * @since 1.18
1680          */
1681         public function getFileSearchOptions() {
1682                 return $this->mImageTimeKeys;
1683         }
1684
1685         /**
1686          * Convert wikitext to HTML and add it to the buffer
1687          * Default assumes that the current page title will be used.
1688          *
1689          * @param string $text
1690          * @param bool $linestart Is this the start of a line?
1691          * @param bool $interface Is this text in the user interface language?
1692          * @throws MWException
1693          */
1694         public function addWikiText( $text, $linestart = true, $interface = true ) {
1695                 $title = $this->getTitle(); // Work around E_STRICT
1696                 if ( !$title ) {
1697                         throw new MWException( 'Title is null' );
1698                 }
1699                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1700         }
1701
1702         /**
1703          * Add wikitext with a custom Title object
1704          *
1705          * @param string $text Wikitext
1706          * @param Title &$title
1707          * @param bool $linestart Is this the start of a line?
1708          */
1709         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1710                 $this->addWikiTextTitle( $text, $title, $linestart );
1711         }
1712
1713         /**
1714          * Add wikitext with a custom Title object and tidy enabled.
1715          *
1716          * @param string $text Wikitext
1717          * @param Title &$title
1718          * @param bool $linestart Is this the start of a line?
1719          */
1720         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1721                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1722         }
1723
1724         /**
1725          * Add wikitext with tidy enabled
1726          *
1727          * @param string $text Wikitext
1728          * @param bool $linestart Is this the start of a line?
1729          */
1730         public function addWikiTextTidy( $text, $linestart = true ) {
1731                 $title = $this->getTitle();
1732                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1733         }
1734
1735         /**
1736          * Add wikitext with a custom Title object
1737          *
1738          * @param string $text Wikitext
1739          * @param Title $title
1740          * @param bool $linestart Is this the start of a line?
1741          * @param bool $tidy Whether to use tidy
1742          * @param bool $interface Whether it is an interface message
1743          *   (for example disables conversion)
1744          */
1745         public function addWikiTextTitle( $text, Title $title, $linestart,
1746                 $tidy = false, $interface = false
1747         ) {
1748                 global $wgParser;
1749
1750                 $popts = $this->parserOptions();
1751                 $oldTidy = $popts->setTidy( $tidy );
1752                 $popts->setInterfaceMessage( (bool)$interface );
1753
1754                 $parserOutput = $wgParser->getFreshParser()->parse(
1755                         $text, $title, $popts,
1756                         $linestart, true, $this->mRevisionId
1757                 );
1758
1759                 $popts->setTidy( $oldTidy );
1760
1761                 $this->addParserOutput( $parserOutput, [
1762                         'enableSectionEditLinks' => false,
1763                 ] );
1764         }
1765
1766         /**
1767          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1768          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1769          * and so on.
1770          *
1771          * @since 1.24
1772          * @param ParserOutput $parserOutput
1773          */
1774         public function addParserOutputMetadata( $parserOutput ) {
1775                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1776                 $this->addCategoryLinks( $parserOutput->getCategories() );
1777                 $this->setIndicators( $parserOutput->getIndicators() );
1778                 $this->mNewSectionLink = $parserOutput->getNewSection();
1779                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1780
1781                 if ( !$parserOutput->isCacheable() ) {
1782                         $this->enableClientCache( false );
1783                 }
1784                 $this->mNoGallery = $parserOutput->getNoGallery();
1785                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1786                 $this->addModules( $parserOutput->getModules() );
1787                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1788                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1789                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1790                 $this->mPreventClickjacking = $this->mPreventClickjacking
1791                         || $parserOutput->preventClickjacking();
1792
1793                 // Template versioning...
1794                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1795                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1796                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1797                         } else {
1798                                 $this->mTemplateIds[$ns] = $dbks;
1799                         }
1800                 }
1801                 // File versioning...
1802                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1803                         $this->mImageTimeKeys[$dbk] = $data;
1804                 }
1805
1806                 // Hooks registered in the object
1807                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1808                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1809                         list( $hookName, $data ) = $hookInfo;
1810                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1811                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1812                         }
1813                 }
1814
1815                 // Enable OOUI if requested via ParserOutput
1816                 if ( $parserOutput->getEnableOOUI() ) {
1817                         $this->enableOOUI();
1818                 }
1819
1820                 // Include parser limit report
1821                 if ( !$this->limitReportJSData ) {
1822                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1823                 }
1824
1825                 // Link flags are ignored for now, but may in the future be
1826                 // used to mark individual language links.
1827                 $linkFlags = [];
1828                 // Avoid PHP 7.1 warning of passing $this by reference
1829                 $outputPage = $this;
1830                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1831                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1832
1833                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
1834                 // so that extensions may modify ParserOutput to toggle TOC.
1835                 // This cannot be moved to addParserOutputText because that is not
1836                 // called by EditPage for Preview.
1837                 if ( $parserOutput->getTOCHTML() ) {
1838                         $this->mEnableTOC = true;
1839                 }
1840         }
1841
1842         /**
1843          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1844          * ParserOutput object, without any other metadata.
1845          *
1846          * @since 1.24
1847          * @param ParserOutput $parserOutput
1848          * @param array $poOptions Options to ParserOutput::getText()
1849          */
1850         public function addParserOutputContent( $parserOutput, $poOptions = [] ) {
1851                 $this->addParserOutputText( $parserOutput, $poOptions );
1852
1853                 $this->addModules( $parserOutput->getModules() );
1854                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1855                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1856
1857                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1858         }
1859
1860         /**
1861          * Add the HTML associated with a ParserOutput object, without any metadata.
1862          *
1863          * @since 1.24
1864          * @param ParserOutput $parserOutput
1865          * @param array $poOptions Options to ParserOutput::getText()
1866          */
1867         public function addParserOutputText( $parserOutput, $poOptions = [] ) {
1868                 $text = $parserOutput->getText( $poOptions );
1869                 // Avoid PHP 7.1 warning of passing $this by reference
1870                 $outputPage = $this;
1871                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1872                 $this->addHTML( $text );
1873         }
1874
1875         /**
1876          * Add everything from a ParserOutput object.
1877          *
1878          * @param ParserOutput $parserOutput
1879          * @param array $poOptions Options to ParserOutput::getText()
1880          */
1881         function addParserOutput( $parserOutput, $poOptions = [] ) {
1882                 $this->addParserOutputMetadata( $parserOutput );
1883                 $this->addParserOutputText( $parserOutput, $poOptions );
1884         }
1885
1886         /**
1887          * Add the output of a QuickTemplate to the output buffer
1888          *
1889          * @param QuickTemplate &$template
1890          */
1891         public function addTemplate( &$template ) {
1892                 $this->addHTML( $template->getHTML() );
1893         }
1894
1895         /**
1896          * Parse wikitext and return the HTML.
1897          *
1898          * @param string $text
1899          * @param bool $linestart Is this the start of a line?
1900          * @param bool $interface Use interface language ($wgLang instead of
1901          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1902          *   This also disables LanguageConverter.
1903          * @param Language|null $language Target language object, will override $interface
1904          * @throws MWException
1905          * @return string HTML
1906          */
1907         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1908                 global $wgParser;
1909
1910                 if ( is_null( $this->getTitle() ) ) {
1911                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1912                 }
1913
1914                 $popts = $this->parserOptions();
1915                 if ( $interface ) {
1916                         $popts->setInterfaceMessage( true );
1917                 }
1918                 if ( $language !== null ) {
1919                         $oldLang = $popts->setTargetLanguage( $language );
1920                 }
1921
1922                 $parserOutput = $wgParser->getFreshParser()->parse(
1923                         $text, $this->getTitle(), $popts,
1924                         $linestart, true, $this->mRevisionId
1925                 );
1926
1927                 if ( $interface ) {
1928                         $popts->setInterfaceMessage( false );
1929                 }
1930                 if ( $language !== null ) {
1931                         $popts->setTargetLanguage( $oldLang );
1932                 }
1933
1934                 return $parserOutput->getText( [
1935                         'enableSectionEditLinks' => false,
1936                 ] );
1937         }
1938
1939         /**
1940          * Parse wikitext, strip paragraphs, and return the HTML.
1941          *
1942          * @param string $text
1943          * @param bool $linestart Is this the start of a line?
1944          * @param bool $interface Use interface language ($wgLang instead of
1945          *   $wgContLang) while parsing language sensitive magic
1946          *   words like GRAMMAR and PLURAL
1947          * @return string HTML
1948          */
1949         public function parseInline( $text, $linestart = true, $interface = false ) {
1950                 $parsed = $this->parse( $text, $linestart, $interface );
1951                 return Parser::stripOuterParagraph( $parsed );
1952         }
1953
1954         /**
1955          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1956          *
1957          * @param int $maxage Maximum cache time on the CDN, in seconds.
1958          */
1959         public function setCdnMaxage( $maxage ) {
1960                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1961         }
1962
1963         /**
1964          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1965          *
1966          * @param int $maxage Maximum cache time on the CDN, in seconds
1967          * @since 1.27
1968          */
1969         public function lowerCdnMaxage( $maxage ) {
1970                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1971                 $this->setCdnMaxage( $this->mCdnMaxage );
1972         }
1973
1974         /**
1975          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
1976          *
1977          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
1978          * the TTL is higher the older the $mtime timestamp is. Essentially, the
1979          * TTL is 90% of the age of the object, subject to the min and max.
1980          *
1981          * @param string|int|float|bool|null $mtime Last-Modified timestamp
1982          * @param int $minTTL Mimimum TTL in seconds [default: 1 minute]
1983          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
1984          * @return int TTL in seconds
1985          * @since 1.28
1986          */
1987         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
1988                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
1989                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
1990
1991                 if ( $mtime === null || $mtime === false ) {
1992                         return $minTTL; // entity does not exist
1993                 }
1994
1995                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
1996                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
1997                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
1998
1999                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2000
2001                 return $adaptiveTTL;
2002         }
2003
2004         /**
2005          * Use enableClientCache(false) to force it to send nocache headers
2006          *
2007          * @param bool $state
2008          *
2009          * @return bool
2010          */
2011         public function enableClientCache( $state ) {
2012                 return wfSetVar( $this->mEnableClientCache, $state );
2013         }
2014
2015         /**
2016          * Get the list of cookies that will influence on the cache
2017          *
2018          * @return array
2019          */
2020         function getCacheVaryCookies() {
2021                 static $cookies;
2022                 if ( $cookies === null ) {
2023                         $config = $this->getConfig();
2024                         $cookies = array_merge(
2025                                 SessionManager::singleton()->getVaryCookies(),
2026                                 [
2027                                         'forceHTTPS',
2028                                 ],
2029                                 $config->get( 'CacheVaryCookies' )
2030                         );
2031                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2032                 }
2033                 return $cookies;
2034         }
2035
2036         /**
2037          * Check if the request has a cache-varying cookie header
2038          * If it does, it's very important that we don't allow public caching
2039          *
2040          * @return bool
2041          */
2042         function haveCacheVaryCookies() {
2043                 $request = $this->getRequest();
2044                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2045                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2046                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2047                                 return true;
2048                         }
2049                 }
2050                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2051                 return false;
2052         }
2053
2054         /**
2055          * Add an HTTP header that will influence on the cache
2056          *
2057          * @param string $header Header name
2058          * @param string[]|null $option Options for the Key header. See
2059          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2060          * for the list of valid options.
2061          */
2062         public function addVaryHeader( $header, array $option = null ) {
2063                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2064                         $this->mVaryHeader[$header] = [];
2065                 }
2066                 if ( !is_array( $option ) ) {
2067                         $option = [];
2068                 }
2069                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2070         }
2071
2072         /**
2073          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2074          * such as Accept-Encoding or Cookie
2075          *
2076          * @return string
2077          */
2078         public function getVaryHeader() {
2079                 // If we vary on cookies, let's make sure it's always included here too.
2080                 if ( $this->getCacheVaryCookies() ) {
2081                         $this->addVaryHeader( 'Cookie' );
2082                 }
2083
2084                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2085                         $this->addVaryHeader( $header, $options );
2086                 }
2087                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2088         }
2089
2090         /**
2091          * Add an HTTP Link: header
2092          *
2093          * @param string $header Header value
2094          */
2095         public function addLinkHeader( $header ) {
2096                 $this->mLinkHeader[] = $header;
2097         }
2098
2099         /**
2100          * Return a Link: header. Based on the values of $mLinkHeader.
2101          *
2102          * @return string
2103          */
2104         public function getLinkHeader() {
2105                 if ( !$this->mLinkHeader ) {
2106                         return false;
2107                 }
2108
2109                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2110         }
2111
2112         /**
2113          * Get a complete Key header
2114          *
2115          * @return string
2116          */
2117         public function getKeyHeader() {
2118                 $cvCookies = $this->getCacheVaryCookies();
2119
2120                 $cookiesOption = [];
2121                 foreach ( $cvCookies as $cookieName ) {
2122                         $cookiesOption[] = 'param=' . $cookieName;
2123                 }
2124                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2125
2126                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2127                         $this->addVaryHeader( $header, $options );
2128                 }
2129
2130                 $headers = [];
2131                 foreach ( $this->mVaryHeader as $header => $option ) {
2132                         $newheader = $header;
2133                         if ( is_array( $option ) && count( $option ) > 0 ) {
2134                                 $newheader .= ';' . implode( ';', $option );
2135                         }
2136                         $headers[] = $newheader;
2137                 }
2138                 $key = 'Key: ' . implode( ',', $headers );
2139
2140                 return $key;
2141         }
2142
2143         /**
2144          * T23672: Add Accept-Language to Vary and Key headers
2145          * if there's no 'variant' parameter existed in GET.
2146          *
2147          * For example:
2148          *   /w/index.php?title=Main_page should always be served; but
2149          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2150          */
2151         function addAcceptLanguage() {
2152                 $title = $this->getTitle();
2153                 if ( !$title instanceof Title ) {
2154                         return;
2155                 }
2156
2157                 $lang = $title->getPageLanguage();
2158                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2159                         $variants = $lang->getVariants();
2160                         $aloption = [];
2161                         foreach ( $variants as $variant ) {
2162                                 if ( $variant === $lang->getCode() ) {
2163                                         continue;
2164                                 } else {
2165                                         $aloption[] = 'substr=' . $variant;
2166
2167                                         // IE and some other browsers use BCP 47 standards in
2168                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2169                                         // We should handle these too.
2170                                         $variantBCP47 = LanguageCode::bcp47( $variant );
2171                                         if ( $variantBCP47 !== $variant ) {
2172                                                 $aloption[] = 'substr=' . $variantBCP47;
2173                                         }
2174                                 }
2175                         }
2176                         $this->addVaryHeader( 'Accept-Language', $aloption );
2177                 }
2178         }
2179
2180         /**
2181          * Set a flag which will cause an X-Frame-Options header appropriate for
2182          * edit pages to be sent. The header value is controlled by
2183          * $wgEditPageFrameOptions.
2184          *
2185          * This is the default for special pages. If you display a CSRF-protected
2186          * form on an ordinary view page, then you need to call this function.
2187          *
2188          * @param bool $enable
2189          */
2190         public function preventClickjacking( $enable = true ) {
2191                 $this->mPreventClickjacking = $enable;
2192         }
2193
2194         /**
2195          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2196          * This can be called from pages which do not contain any CSRF-protected
2197          * HTML form.
2198          */
2199         public function allowClickjacking() {
2200                 $this->mPreventClickjacking = false;
2201         }
2202
2203         /**
2204          * Get the prevent-clickjacking flag
2205          *
2206          * @since 1.24
2207          * @return bool
2208          */
2209         public function getPreventClickjacking() {
2210                 return $this->mPreventClickjacking;
2211         }
2212
2213         /**
2214          * Get the X-Frame-Options header value (without the name part), or false
2215          * if there isn't one. This is used by Skin to determine whether to enable
2216          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2217          *
2218          * @return string|false
2219          */
2220         public function getFrameOptions() {
2221                 $config = $this->getConfig();
2222                 if ( $config->get( 'BreakFrames' ) ) {
2223                         return 'DENY';
2224                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2225                         return $config->get( 'EditPageFrameOptions' );
2226                 }
2227                 return false;
2228         }
2229
2230         /**
2231          * Send cache control HTTP headers
2232          */
2233         public function sendCacheControl() {
2234                 $response = $this->getRequest()->response();
2235                 $config = $this->getConfig();
2236
2237                 $this->addVaryHeader( 'Cookie' );
2238                 $this->addAcceptLanguage();
2239
2240                 # don't serve compressed data to clients who can't handle it
2241                 # maintain different caches for logged-in users and non-logged in ones
2242                 $response->header( $this->getVaryHeader() );
2243
2244                 if ( $config->get( 'UseKeyHeader' ) ) {
2245                         $response->header( $this->getKeyHeader() );
2246                 }
2247
2248                 if ( $this->mEnableClientCache ) {
2249                         if (
2250                                 $config->get( 'UseSquid' ) &&
2251                                 !$response->hasCookies() &&
2252                                 !SessionManager::getGlobalSession()->isPersistent() &&
2253                                 !$this->isPrintable() &&
2254                                 $this->mCdnMaxage != 0 &&
2255                                 !$this->haveCacheVaryCookies()
2256                         ) {
2257                                 if ( $config->get( 'UseESI' ) ) {
2258                                         # We'll purge the proxy cache explicitly, but require end user agents
2259                                         # to revalidate against the proxy on each visit.
2260                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2261                                         wfDebug( __METHOD__ .
2262                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2263                                         # start with a shorter timeout for initial testing
2264                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2265                                         $response->header(
2266                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2267                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2268                                         );
2269                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2270                                 } else {
2271                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2272                                         # to revalidate against the proxy on each visit.
2273                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2274                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2275                                         wfDebug( __METHOD__ .
2276                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2277                                         # start with a shorter timeout for initial testing
2278                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2279                                         $response->header( "Cache-Control: " .
2280                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2281                                 }
2282                         } else {
2283                                 # We do want clients to cache if they can, but they *must* check for updates
2284                                 # on revisiting the page.
2285                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2286                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2287                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2288                         }
2289                         if ( $this->mLastModified ) {
2290                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2291                         }
2292                 } else {
2293                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2294
2295                         # In general, the absence of a last modified header should be enough to prevent
2296                         # the client from using its cache. We send a few other things just to make sure.
2297                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2298                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2299                         $response->header( 'Pragma: no-cache' );
2300                 }
2301         }
2302
2303         /**
2304          * Transfer styles and JavaScript modules from skin.
2305          *
2306          * @param Skin $sk to load modules for
2307          */
2308         public function loadSkinModules( $sk ) {
2309                 foreach ( $sk->getDefaultModules() as $group => $modules ) {
2310                         if ( $group === 'styles' ) {
2311                                 foreach ( $modules as $key => $moduleMembers ) {
2312                                         $this->addModuleStyles( $moduleMembers );
2313                                 }
2314                         } else {
2315                                 $this->addModules( $modules );
2316                         }
2317                 }
2318         }
2319
2320         /**
2321          * Finally, all the text has been munged and accumulated into
2322          * the object, let's actually output it:
2323          *
2324          * @param bool $return Set to true to get the result as a string rather than sending it
2325          * @return string|null
2326          * @throws Exception
2327          * @throws FatalError
2328          * @throws MWException
2329          */
2330         public function output( $return = false ) {
2331                 global $wgContLang;
2332
2333                 if ( $this->mDoNothing ) {
2334                         return $return ? '' : null;
2335                 }
2336
2337                 $response = $this->getRequest()->response();
2338                 $config = $this->getConfig();
2339
2340                 if ( $this->mRedirect != '' ) {
2341                         # Standards require redirect URLs to be absolute
2342                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2343
2344                         $redirect = $this->mRedirect;
2345                         $code = $this->mRedirectCode;
2346
2347                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2348                                 if ( $code == '301' || $code == '303' ) {
2349                                         if ( !$config->get( 'DebugRedirects' ) ) {
2350                                                 $response->statusHeader( $code );
2351                                         }
2352                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2353                                 }
2354                                 if ( $config->get( 'VaryOnXFP' ) ) {
2355                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2356                                 }
2357                                 $this->sendCacheControl();
2358
2359                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2360                                 if ( $config->get( 'DebugRedirects' ) ) {
2361                                         $url = htmlspecialchars( $redirect );
2362                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2363                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2364                                         print "</body>\n</html>\n";
2365                                 } else {
2366                                         $response->header( 'Location: ' . $redirect );
2367                                 }
2368                         }
2369
2370                         return $return ? '' : null;
2371                 } elseif ( $this->mStatusCode ) {
2372                         $response->statusHeader( $this->mStatusCode );
2373                 }
2374
2375                 # Buffer output; final headers may depend on later processing
2376                 ob_start();
2377
2378                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2379                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2380
2381                 if ( !$this->mArticleBodyOnly ) {
2382                         $sk = $this->getSkin();
2383
2384                         if ( $sk->shouldPreloadLogo() ) {
2385                                 $this->addLogoPreloadLinkHeaders();
2386                         }
2387                 }
2388
2389                 $linkHeader = $this->getLinkHeader();
2390                 if ( $linkHeader ) {
2391                         $response->header( $linkHeader );
2392                 }
2393
2394                 // Prevent framing, if requested
2395                 $frameOptions = $this->getFrameOptions();
2396                 if ( $frameOptions ) {
2397                         $response->header( "X-Frame-Options: $frameOptions" );
2398                 }
2399
2400                 ContentSecurityPolicy::sendHeaders( $this );
2401
2402                 if ( $this->mArticleBodyOnly ) {
2403                         echo $this->mBodytext;
2404                 } else {
2405                         // Enable safe mode if requested (T152169)
2406                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2407                                 $this->disallowUserJs();
2408                         }
2409
2410                         $sk = $this->getSkin();
2411                         $this->loadSkinModules( $sk );
2412
2413                         MWDebug::addModules( $this );
2414
2415                         // Avoid PHP 7.1 warning of passing $this by reference
2416                         $outputPage = $this;
2417                         // Hook that allows last minute changes to the output page, e.g.
2418                         // adding of CSS or Javascript by extensions.
2419                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2420
2421                         try {
2422                                 $sk->outputPage();
2423                         } catch ( Exception $e ) {
2424                                 ob_end_clean(); // bug T129657
2425                                 throw $e;
2426                         }
2427                 }
2428
2429                 try {
2430                         // This hook allows last minute changes to final overall output by modifying output buffer
2431                         Hooks::runWithoutAbort( 'AfterFinalPageOutput', [ $this ] );
2432                 } catch ( Exception $e ) {
2433                         ob_end_clean(); // bug T129657
2434                         throw $e;
2435                 }
2436
2437                 $this->sendCacheControl();
2438
2439                 if ( $return ) {
2440                         return ob_get_clean();
2441                 } else {
2442                         ob_end_flush();
2443                         return null;
2444                 }
2445         }
2446
2447         /**
2448          * Prepare this object to display an error page; disable caching and
2449          * indexing, clear the current text and redirect, set the page's title
2450          * and optionally an custom HTML title (content of the "<title>" tag).
2451          *
2452          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2453          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2454          *                   optional, if not passed the "<title>" attribute will be
2455          *                   based on $pageTitle
2456          */
2457         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2458                 $this->setPageTitle( $pageTitle );
2459                 if ( $htmlTitle !== false ) {
2460                         $this->setHTMLTitle( $htmlTitle );
2461                 }
2462                 $this->setRobotPolicy( 'noindex,nofollow' );
2463                 $this->setArticleRelated( false );
2464                 $this->enableClientCache( false );
2465                 $this->mRedirect = '';
2466                 $this->clearSubtitle();
2467                 $this->clearHTML();
2468         }
2469
2470         /**
2471          * Output a standard error page
2472          *
2473          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2474          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2475          * showErrorPage( 'titlemsg', $messageObject );
2476          * showErrorPage( $titleMessageObject, $messageObject );
2477          *
2478          * @param string|Message $title Message key (string) for page title, or a Message object
2479          * @param string|Message $msg Message key (string) for page text, or a Message object
2480          * @param array $params Message parameters; ignored if $msg is a Message object
2481          */
2482         public function showErrorPage( $title, $msg, $params = [] ) {
2483                 if ( !$title instanceof Message ) {
2484                         $title = $this->msg( $title );
2485                 }
2486
2487                 $this->prepareErrorPage( $title );
2488
2489                 if ( $msg instanceof Message ) {
2490                         if ( $params !== [] ) {
2491                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2492                                         . 'is discarded when the $msg argument is a Message object instead of '
2493                                         . 'a string.', E_USER_NOTICE );
2494                         }
2495                         $this->addHTML( $msg->parseAsBlock() );
2496                 } else {
2497                         $this->addWikiMsgArray( $msg, $params );
2498                 }
2499
2500                 $this->returnToMain();
2501         }
2502
2503         /**
2504          * Output a standard permission error page
2505          *
2506          * @param array $errors Error message keys or [key, param...] arrays
2507          * @param string|null $action Action that was denied or null if unknown
2508          */
2509         public function showPermissionsErrorPage( array $errors, $action = null ) {
2510                 foreach ( $errors as $key => $error ) {
2511                         $errors[$key] = (array)$error;
2512                 }
2513
2514                 // For some action (read, edit, create and upload), display a "login to do this action"
2515                 // error if all of the following conditions are met:
2516                 // 1. the user is not logged in
2517                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2518                 // 3. the error can be avoided simply by logging in
2519                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2520                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2521                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2522                         && ( User::groupHasPermission( 'user', $action )
2523                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2524                 ) {
2525                         $displayReturnto = null;
2526
2527                         # Due to T34276, if a user does not have read permissions,
2528                         # $this->getTitle() will just give Special:Badtitle, which is
2529                         # not especially useful as a returnto parameter. Use the title
2530                         # from the request instead, if there was one.
2531                         $request = $this->getRequest();
2532                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2533                         if ( $action == 'edit' ) {
2534                                 $msg = 'whitelistedittext';
2535                                 $displayReturnto = $returnto;
2536                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2537                                 $msg = 'nocreatetext';
2538                         } elseif ( $action == 'upload' ) {
2539                                 $msg = 'uploadnologintext';
2540                         } else { # Read
2541                                 $msg = 'loginreqpagetext';
2542                                 $displayReturnto = Title::newMainPage();
2543                         }
2544
2545                         $query = [];
2546
2547                         if ( $returnto ) {
2548                                 $query['returnto'] = $returnto->getPrefixedText();
2549
2550                                 if ( !$request->wasPosted() ) {
2551                                         $returntoquery = $request->getValues();
2552                                         unset( $returntoquery['title'] );
2553                                         unset( $returntoquery['returnto'] );
2554                                         unset( $returntoquery['returntoquery'] );
2555                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2556                                 }
2557                         }
2558                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2559                         $loginLink = $linkRenderer->makeKnownLink(
2560                                 SpecialPage::getTitleFor( 'Userlogin' ),
2561                                 $this->msg( 'loginreqlink' )->text(),
2562                                 [],
2563                                 $query
2564                         );
2565
2566                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2567                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2568
2569                         # Don't return to a page the user can't read otherwise
2570                         # we'll end up in a pointless loop
2571                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2572                                 $this->returnToMain( null, $displayReturnto );
2573                         }
2574                 } else {
2575                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2576                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2577                 }
2578         }
2579
2580         /**
2581          * Display an error page indicating that a given version of MediaWiki is
2582          * required to use it
2583          *
2584          * @param mixed $version The version of MediaWiki needed to use the page
2585          */
2586         public function versionRequired( $version ) {
2587                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2588
2589                 $this->addWikiMsg( 'versionrequiredtext', $version );
2590                 $this->returnToMain();
2591         }
2592
2593         /**
2594          * Format a list of error messages
2595          *
2596          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2597          * @param string|null $action Action that was denied or null if unknown
2598          * @return string The wikitext error-messages, formatted into a list.
2599          */
2600         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2601                 if ( $action == null ) {
2602                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2603                 } else {
2604                         $action_desc = $this->msg( "action-$action" )->plain();
2605                         $text = $this->msg(
2606                                 'permissionserrorstext-withaction',
2607                                 count( $errors ),
2608                                 $action_desc
2609                         )->plain() . "\n\n";
2610                 }
2611
2612                 if ( count( $errors ) > 1 ) {
2613                         $text .= '<ul class="permissions-errors">' . "\n";
2614
2615                         foreach ( $errors as $error ) {
2616                                 $text .= '<li>';
2617                                 $text .= $this->msg( ...$error )->plain();
2618                                 $text .= "</li>\n";
2619                         }
2620                         $text .= '</ul>';
2621                 } else {
2622                         $text .= "<div class=\"permissions-errors\">\n" .
2623                                         $this->msg( ...reset( $errors ) )->plain() .
2624                                         "\n</div>";
2625                 }
2626
2627                 return $text;
2628         }
2629
2630         /**
2631          * Show a warning about replica DB lag
2632          *
2633          * If the lag is higher than $wgSlaveLagCritical seconds,
2634          * then the warning is a bit more obvious. If the lag is
2635          * lower than $wgSlaveLagWarning, then no warning is shown.
2636          *
2637          * @param int $lag Slave lag
2638          */
2639         public function showLagWarning( $lag ) {
2640                 $config = $this->getConfig();
2641                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2642                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2643                         $message = $lag < $config->get( 'SlaveLagCritical' )
2644                                 ? 'lag-warn-normal'
2645                                 : 'lag-warn-high';
2646                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2647                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2648                 }
2649         }
2650
2651         /**
2652          * Output an error page
2653          *
2654          * @note FatalError exception class provides an alternative.
2655          * @param string $message Error to output. Must be escaped for HTML.
2656          */
2657         public function showFatalError( $message ) {
2658                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2659
2660                 $this->addHTML( $message );
2661         }
2662
2663         /**
2664          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2665          */
2666         public function showUnexpectedValueError( $name, $val ) {
2667                 wfDeprecated( __METHOD__, '1.32' );
2668                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->escaped() );
2669         }
2670
2671         /**
2672          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2673          */
2674         public function showFileCopyError( $old, $new ) {
2675                 wfDeprecated( __METHOD__, '1.32' );
2676                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->escaped() );
2677         }
2678
2679         /**
2680          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2681          */
2682         public function showFileRenameError( $old, $new ) {
2683                 wfDeprecated( __METHOD__, '1.32' );
2684                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->escpaed() );
2685         }
2686
2687         /**
2688          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2689          */
2690         public function showFileDeleteError( $name ) {
2691                 wfDeprecated( __METHOD__, '1.32' );
2692                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->escaped() );
2693         }
2694
2695         /**
2696          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2697          */
2698         public function showFileNotFoundError( $name ) {
2699                 wfDeprecated( __METHOD__, '1.32' );
2700                 $this->showFatalError( $this->msg( 'filenotfound', $name )->escaped() );
2701         }
2702
2703         /**
2704          * Add a "return to" link pointing to a specified title
2705          *
2706          * @param Title $title Title to link
2707          * @param array $query Query string parameters
2708          * @param string|null $text Text of the link (input is not escaped)
2709          * @param array $options Options array to pass to Linker
2710          */
2711         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2712                 $linkRenderer = MediaWikiServices::getInstance()
2713                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
2714                 $link = $this->msg( 'returnto' )->rawParams(
2715                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
2716                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2717         }
2718
2719         /**
2720          * Add a "return to" link pointing to a specified title,
2721          * or the title indicated in the request, or else the main page
2722          *
2723          * @param mixed|null $unused
2724          * @param Title|string|null $returnto Title or String to return to
2725          * @param string|null $returntoquery Query string for the return to link
2726          */
2727         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2728                 if ( $returnto == null ) {
2729                         $returnto = $this->getRequest()->getText( 'returnto' );
2730                 }
2731
2732                 if ( $returntoquery == null ) {
2733                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2734                 }
2735
2736                 if ( $returnto === '' ) {
2737                         $returnto = Title::newMainPage();
2738                 }
2739
2740                 if ( is_object( $returnto ) ) {
2741                         $titleObj = $returnto;
2742                 } else {
2743                         $titleObj = Title::newFromText( $returnto );
2744                 }
2745                 // We don't want people to return to external interwiki. That
2746                 // might potentially be used as part of a phishing scheme
2747                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
2748                         $titleObj = Title::newMainPage();
2749                 }
2750
2751                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2752         }
2753
2754         private function getRlClientContext() {
2755                 if ( !$this->rlClientContext ) {
2756                         $query = ResourceLoader::makeLoaderQuery(
2757                                 [], // modules; not relevant
2758                                 $this->getLanguage()->getCode(),
2759                                 $this->getSkin()->getSkinName(),
2760                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2761                                 null, // version; not relevant
2762                                 ResourceLoader::inDebugMode(),
2763                                 null, // only; not relevant
2764                                 $this->isPrintable(),
2765                                 $this->getRequest()->getBool( 'handheld' )
2766                         );
2767                         $this->rlClientContext = new ResourceLoaderContext(
2768                                 $this->getResourceLoader(),
2769                                 new FauxRequest( $query )
2770                         );
2771                         if ( $this->contentOverrideCallbacks ) {
2772                                 $this->rlClientContext = new DerivativeResourceLoaderContext( $this->rlClientContext );
2773                                 $this->rlClientContext->setContentOverrideCallback( function ( Title $title ) {
2774                                         foreach ( $this->contentOverrideCallbacks as $callback ) {
2775                                                 $content = call_user_func( $callback, $title );
2776                                                 if ( $content !== null ) {
2777                                                         return $content;
2778                                                 }
2779                                         }
2780                                         return null;
2781                                 } );
2782                         }
2783                 }
2784                 return $this->rlClientContext;
2785         }
2786
2787         /**
2788          * Call this to freeze the module queue and JS config and create a formatter.
2789          *
2790          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2791          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2792          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2793          * the module filters retroactively. Skins and extension hooks may also add modules until very
2794          * late in the request lifecycle.
2795          *
2796          * @return ResourceLoaderClientHtml
2797          */
2798         public function getRlClient() {
2799                 if ( !$this->rlClient ) {
2800                         $context = $this->getRlClientContext();
2801                         $rl = $this->getResourceLoader();
2802                         $this->addModules( [
2803                                 'user',
2804                                 'user.options',
2805                                 'user.tokens',
2806                         ] );
2807                         $this->addModuleStyles( [
2808                                 'site.styles',
2809                                 'noscript',
2810                                 'user.styles',
2811                         ] );
2812                         $this->getSkin()->setupSkinUserCss( $this );
2813
2814                         // Prepare exempt modules for buildExemptModules()
2815                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2816                         $exemptStates = [];
2817                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2818
2819                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2820                         // Separate user-specific batch for improved cache-hit ratio.
2821                         $userBatch = [ 'user.styles', 'user' ];
2822                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2823                         $dbr = wfGetDB( DB_REPLICA );
2824                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2825                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2826
2827                         // Filter out modules handled by buildExemptModules()
2828                         $moduleStyles = array_filter( $moduleStyles,
2829                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2830                                         $module = $rl->getModule( $name );
2831                                         if ( $module ) {
2832                                                 $group = $module->getGroup();
2833                                                 if ( isset( $exemptGroups[$group] ) ) {
2834                                                         $exemptStates[$name] = 'ready';
2835                                                         if ( !$module->isKnownEmpty( $context ) ) {
2836                                                                 // E.g. Don't output empty <styles>
2837                                                                 $exemptGroups[$group][] = $name;
2838                                                         }
2839                                                         return false;
2840                                                 }
2841                                         }
2842                                         return true;
2843                                 }
2844                         );
2845                         $this->rlExemptStyleModules = $exemptGroups;
2846
2847                         $rlClient = new ResourceLoaderClientHtml( $context, [
2848                                 'target' => $this->getTarget(),
2849                                 'nonce' => $this->getCSPNonce(),
2850                                 // When 'safemode', disallowUserJs(), or reduceAllowedModules() is used
2851                                 // to only restrict modules to ORIGIN_CORE (ie. disallow ORIGIN_USER), the list of
2852                                 // modules enqueud for loading on this page is filtered to just those.
2853                                 // However, to make sure we also apply the restriction to dynamic dependencies and
2854                                 // lazy-loaded modules at run-time on the client-side, pass 'safemode' down to the
2855                                 // StartupModule so that the client-side registry will not contain any restricted
2856                                 // modules either. (T152169, T185303)
2857                                 'safemode' => ( $this->getAllowedModules( ResourceLoaderModule::TYPE_COMBINED )
2858                                         <= ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
2859                                 ) ? '1' : null,
2860                         ] );
2861                         $rlClient->setConfig( $this->getJSVars() );
2862                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2863                         $rlClient->setModuleStyles( $moduleStyles );
2864                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2865                         $rlClient->setExemptStates( $exemptStates );
2866                         $this->rlClient = $rlClient;
2867                 }
2868                 return $this->rlClient;
2869         }
2870
2871         /**
2872          * @param Skin $sk The given Skin
2873          * @param bool $includeStyle Unused
2874          * @return string The doctype, opening "<html>", and head element.
2875          */
2876         public function headElement( Skin $sk, $includeStyle = true ) {
2877                 global $wgContLang;
2878
2879                 $userdir = $this->getLanguage()->getDir();
2880                 $sitedir = $wgContLang->getDir();
2881
2882                 $pieces = [];
2883                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2884                         $this->getRlClient()->getDocumentAttributes(),
2885                         $sk->getHtmlElementAttributes()
2886                 ) );
2887                 $pieces[] = Html::openElement( 'head' );
2888
2889                 if ( $this->getHTMLTitle() == '' ) {
2890                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2891                 }
2892
2893                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2894                         // Add <meta charset="UTF-8">
2895                         // This should be before <title> since it defines the charset used by
2896                         // text including the text inside <title>.
2897                         // The spec recommends defining XHTML5's charset using the XML declaration
2898                         // instead of meta.
2899                         // Our XML declaration is output by Html::htmlHeader.
2900                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2901                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2902                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2903                 }
2904
2905                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2906                 $pieces[] = $this->getRlClient()->getHeadHtml();
2907                 $pieces[] = $this->buildExemptModules();
2908                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2909                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2910
2911                 // Use an IE conditional comment to serve the script only to old IE
2912                 $pieces[] = '<!--[if lt IE 9]>' .
2913                         ResourceLoaderClientHtml::makeLoad(
2914                                 ResourceLoaderContext::newDummyContext(),
2915                                 [ 'html5shiv' ],
2916                                 ResourceLoaderModule::TYPE_SCRIPTS,
2917                                 [ 'sync' => true ],
2918                                 $this->getCSPNonce()
2919                         ) .
2920                         '<![endif]-->';
2921
2922                 $pieces[] = Html::closeElement( 'head' );
2923
2924                 $bodyClasses = $this->mAdditionalBodyClasses;
2925                 $bodyClasses[] = 'mediawiki';
2926
2927                 # Classes for LTR/RTL directionality support
2928                 $bodyClasses[] = $userdir;
2929                 $bodyClasses[] = "sitedir-$sitedir";
2930
2931                 $underline = $this->getUser()->getOption( 'underline' );
2932                 if ( $underline < 2 ) {
2933                         // The following classes can be used here:
2934                         // * mw-underline-always
2935                         // * mw-underline-never
2936                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2937                 }
2938
2939                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2940                         # A <body> class is probably not the best way to do this . . .
2941                         $bodyClasses[] = 'capitalize-all-nouns';
2942                 }
2943
2944                 // Parser feature migration class
2945                 // The idea is that this will eventually be removed, after the wikitext
2946                 // which requires it is cleaned up.
2947                 $bodyClasses[] = 'mw-hide-empty-elt';
2948
2949                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2950                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2951                 $bodyClasses[] =
2952                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2953
2954                 $bodyAttrs = [];
2955                 // While the implode() is not strictly needed, it's used for backwards compatibility
2956                 // (this used to be built as a string and hooks likely still expect that).
2957                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2958
2959                 // Allow skins and extensions to add body attributes they need
2960                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2961                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2962
2963                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2964
2965                 return self::combineWrappedStrings( $pieces );
2966         }
2967
2968         /**
2969          * Get a ResourceLoader object associated with this OutputPage
2970          *
2971          * @return ResourceLoader
2972          */
2973         public function getResourceLoader() {
2974                 if ( is_null( $this->mResourceLoader ) ) {
2975                         $this->mResourceLoader = new ResourceLoader(
2976                                 $this->getConfig(),
2977                                 LoggerFactory::getInstance( 'resourceloader' )
2978                         );
2979                 }
2980                 return $this->mResourceLoader;
2981         }
2982
2983         /**
2984          * Explicily load or embed modules on a page.
2985          *
2986          * @param array|string $modules One or more module names
2987          * @param string $only ResourceLoaderModule TYPE_ class constant
2988          * @param array $extraQuery [optional] Array with extra query parameters for the request
2989          * @return string|WrappedStringList HTML
2990          */
2991         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2992                 // Apply 'target' and 'origin' filters
2993                 $modules = $this->filterModules( (array)$modules, null, $only );
2994
2995                 return ResourceLoaderClientHtml::makeLoad(
2996                         $this->getRlClientContext(),
2997                         $modules,
2998                         $only,
2999                         $extraQuery,
3000                         $this->getCSPNonce()
3001                 );
3002         }
3003
3004         /**
3005          * Combine WrappedString chunks and filter out empty ones
3006          *
3007          * @param array $chunks
3008          * @return string|WrappedStringList HTML
3009          */
3010         protected static function combineWrappedStrings( array $chunks ) {
3011                 // Filter out empty values
3012                 $chunks = array_filter( $chunks, 'strlen' );
3013                 return WrappedString::join( "\n", $chunks );
3014         }
3015
3016         /**
3017          * JS stuff to put at the bottom of the `<body>`.
3018          * These are legacy scripts ($this->mScripts), and user JS.
3019          *
3020          * @return string|WrappedStringList HTML
3021          */
3022         public function getBottomScripts() {
3023                 $chunks = [];
3024                 $chunks[] = $this->getRlClient()->getBodyHtml();
3025
3026                 // Legacy non-ResourceLoader scripts
3027                 $chunks[] = $this->mScripts;
3028
3029                 if ( $this->limitReportJSData ) {
3030                         $chunks[] = ResourceLoader::makeInlineScript(
3031                                 ResourceLoader::makeConfigSetScript(
3032                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3033                                 ),
3034                                 $this->getCSPNonce()
3035                         );
3036                 }
3037
3038                 return self::combineWrappedStrings( $chunks );
3039         }
3040
3041         /**
3042          * Get the javascript config vars to include on this page
3043          *
3044          * @return array Array of javascript config vars
3045          * @since 1.23
3046          */
3047         public function getJsConfigVars() {
3048                 return $this->mJsConfigVars;
3049         }
3050
3051         /**
3052          * Add one or more variables to be set in mw.config in JavaScript
3053          *
3054          * @param string|array $keys Key or array of key/value pairs
3055          * @param mixed|null $value [optional] Value of the configuration variable
3056          */
3057         public function addJsConfigVars( $keys, $value = null ) {
3058                 if ( is_array( $keys ) ) {
3059                         foreach ( $keys as $key => $value ) {
3060                                 $this->mJsConfigVars[$key] = $value;
3061                         }
3062                         return;
3063                 }
3064
3065                 $this->mJsConfigVars[$keys] = $value;
3066         }
3067
3068         /**
3069          * Get an array containing the variables to be set in mw.config in JavaScript.
3070          *
3071          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3072          * - in other words, page-independent/site-wide variables (without state).
3073          * You will only be adding bloat to the html page and causing page caches to
3074          * have to be purged on configuration changes.
3075          * @return array
3076          */
3077         public function getJSVars() {
3078                 global $wgContLang;
3079
3080                 $curRevisionId = 0;
3081                 $articleId = 0;
3082                 $canonicalSpecialPageName = false; # T23115
3083
3084                 $title = $this->getTitle();
3085                 $ns = $title->getNamespace();
3086                 $canonicalNamespace = MWNamespace::exists( $ns )
3087                         ? MWNamespace::getCanonicalName( $ns )
3088                         : $title->getNsText();
3089
3090                 $sk = $this->getSkin();
3091                 // Get the relevant title so that AJAX features can use the correct page name
3092                 // when making API requests from certain special pages (T36972).
3093                 $relevantTitle = $sk->getRelevantTitle();
3094                 $relevantUser = $sk->getRelevantUser();
3095
3096                 if ( $ns == NS_SPECIAL ) {
3097                         list( $canonicalSpecialPageName, /*...*/ ) =
3098                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3099                 } elseif ( $this->canUseWikiPage() ) {
3100                         $wikiPage = $this->getWikiPage();
3101                         $curRevisionId = $wikiPage->getLatest();
3102                         $articleId = $wikiPage->getId();
3103                 }
3104
3105                 $lang = $title->getPageViewLanguage();
3106
3107                 // Pre-process information
3108                 $separatorTransTable = $lang->separatorTransformTable();
3109                 $separatorTransTable = $separatorTransTable ?: [];
3110                 $compactSeparatorTransTable = [
3111                         implode( "\t", array_keys( $separatorTransTable ) ),
3112                         implode( "\t", $separatorTransTable ),
3113                 ];
3114                 $digitTransTable = $lang->digitTransformTable();
3115                 $digitTransTable = $digitTransTable ?: [];
3116                 $compactDigitTransTable = [
3117                         implode( "\t", array_keys( $digitTransTable ) ),
3118                         implode( "\t", $digitTransTable ),
3119                 ];
3120
3121                 $user = $this->getUser();
3122
3123                 $vars = [
3124                         'wgCanonicalNamespace' => $canonicalNamespace,
3125                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3126                         'wgNamespaceNumber' => $title->getNamespace(),
3127                         'wgPageName' => $title->getPrefixedDBkey(),
3128                         'wgTitle' => $title->getText(),
3129                         'wgCurRevisionId' => $curRevisionId,
3130                         'wgRevisionId' => (int)$this->getRevisionId(),
3131                         'wgArticleId' => $articleId,
3132                         'wgIsArticle' => $this->isArticle(),
3133                         'wgIsRedirect' => $title->isRedirect(),
3134                         'wgAction' => Action::getActionName( $this->getContext() ),
3135                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3136                         'wgUserGroups' => $user->getEffectiveGroups(),
3137                         'wgCategories' => $this->getCategories(),
3138                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3139                         'wgPageContentLanguage' => $lang->getCode(),
3140                         'wgPageContentModel' => $title->getContentModel(),
3141                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3142                         'wgDigitTransformTable' => $compactDigitTransTable,
3143                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3144                         'wgMonthNames' => $lang->getMonthNamesArray(),
3145                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3146                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3147                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3148                         'wgRequestId' => WebRequest::getRequestId(),
3149                 ];
3150
3151                 if ( $user->isLoggedIn() ) {
3152                         $vars['wgUserId'] = $user->getId();
3153                         $vars['wgUserEditCount'] = $user->getEditCount();
3154                         $userReg = $user->getRegistration();
3155                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3156                         // Get the revision ID of the oldest new message on the user's talk
3157                         // page. This can be used for constructing new message alerts on
3158                         // the client side.
3159                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3160                 }
3161
3162                 if ( $wgContLang->hasVariants() ) {
3163                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3164                 }
3165                 // Same test as SkinTemplate
3166                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3167                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3168
3169                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3170                         && $relevantTitle->quickUserCan( 'edit', $user )
3171                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3172
3173                 foreach ( $title->getRestrictionTypes() as $type ) {
3174                         // Following keys are set in $vars:
3175                         // wgRestrictionCreate, wgRestrictionEdit, wgRestrictionMove, wgRestrictionUpload
3176                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3177                 }
3178
3179                 if ( $title->isMainPage() ) {
3180                         $vars['wgIsMainPage'] = true;
3181                 }
3182
3183                 if ( $this->mRedirectedFrom ) {
3184                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3185                 }
3186
3187                 if ( $relevantUser ) {
3188                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3189                 }
3190
3191                 // Allow extensions to add their custom variables to the mw.config map.
3192                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3193                 // page-dependant but site-wide (without state).
3194                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3195                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3196
3197                 // Merge in variables from addJsConfigVars last
3198                 return array_merge( $vars, $this->getJsConfigVars() );
3199         }
3200
3201         /**
3202          * To make it harder for someone to slip a user a fake
3203          * JavaScript or CSS preview, a random token
3204          * is associated with the login session. If it's not
3205          * passed back with the preview request, we won't render
3206          * the code.
3207          *
3208          * @return bool
3209          */
3210         public function userCanPreview() {
3211                 $request = $this->getRequest();
3212                 if (
3213                         $request->getVal( 'action' ) !== 'submit' ||
3214                         !$request->wasPosted()
3215                 ) {
3216                         return false;
3217                 }
3218
3219                 $user = $this->getUser();
3220
3221                 if ( !$user->isLoggedIn() ) {
3222                         // Anons have predictable edit tokens
3223                         return false;
3224                 }
3225                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3226                         return false;
3227                 }
3228
3229                 $title = $this->getTitle();
3230                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3231                 if ( count( $errors ) !== 0 ) {
3232                         return false;
3233                 }
3234
3235                 return true;
3236         }
3237
3238         /**
3239          * @return array Array in format "link name or number => 'link html'".
3240          */
3241         public function getHeadLinksArray() {
3242                 global $wgVersion;
3243
3244                 $tags = [];
3245                 $config = $this->getConfig();
3246
3247                 $canonicalUrl = $this->mCanonicalUrl;
3248
3249                 $tags['meta-generator'] = Html::element( 'meta', [
3250                         'name' => 'generator',
3251                         'content' => "MediaWiki $wgVersion",
3252                 ] );
3253
3254                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3255                         // Per https://w3c.github.io/webappsec-referrer-policy/#unknown-policy-values
3256                         // fallbacks should come before the primary value so we need to reverse the array.
3257                         foreach ( array_reverse( (array)$config->get( 'ReferrerPolicy' ) ) as $i => $policy ) {
3258                                 $tags["meta-referrer-$i"] = Html::element( 'meta', [
3259                                         'name' => 'referrer',
3260                                         'content' => $policy,
3261                                 ] );
3262                         }
3263                 }
3264
3265                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3266                 if ( $p !== 'index,follow' ) {
3267                         // http://www.robotstxt.org/wc/meta-user.html
3268                         // Only show if it's different from the default robots policy
3269                         $tags['meta-robots'] = Html::element( 'meta', [
3270                                 'name' => 'robots',
3271                                 'content' => $p,
3272                         ] );
3273                 }
3274
3275                 foreach ( $this->mMetatags as $tag ) {
3276                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3277                                 $a = 'http-equiv';
3278                                 $tag[0] = substr( $tag[0], 5 );
3279                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3280                                 $a = 'property';
3281                         } else {
3282                                 $a = 'name';
3283                         }
3284                         $tagName = "meta-{$tag[0]}";
3285                         if ( isset( $tags[$tagName] ) ) {
3286                                 $tagName .= $tag[1];
3287                         }
3288                         $tags[$tagName] = Html::element( 'meta',
3289                                 [
3290                                         $a => $tag[0],
3291                                         'content' => $tag[1]
3292                                 ]
3293                         );
3294                 }
3295
3296                 foreach ( $this->mLinktags as $tag ) {
3297                         $tags[] = Html::element( 'link', $tag );
3298                 }
3299
3300                 # Universal edit button
3301                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3302                         $user = $this->getUser();
3303                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3304                                 && ( $this->getTitle()->exists() ||
3305                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3306                         ) {
3307                                 // Original UniversalEditButton
3308                                 $msg = $this->msg( 'edit' )->text();
3309                                 $tags['universal-edit-button'] = Html::element( 'link', [
3310                                         'rel' => 'alternate',
3311                                         'type' => 'application/x-wiki',
3312                                         'title' => $msg,
3313                                         'href' => $this->getTitle()->getEditURL(),
3314                                 ] );
3315                                 // Alternate edit link
3316                                 $tags['alternative-edit'] = Html::element( 'link', [
3317                                         'rel' => 'edit',
3318                                         'title' => $msg,
3319                                         'href' => $this->getTitle()->getEditURL(),
3320                                 ] );
3321                         }
3322                 }
3323
3324                 # Generally the order of the favicon and apple-touch-icon links
3325                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3326                 # uses whichever one appears later in the HTML source. Make sure
3327                 # apple-touch-icon is specified first to avoid this.
3328                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3329                         $tags['apple-touch-icon'] = Html::element( 'link', [
3330                                 'rel' => 'apple-touch-icon',
3331                                 'href' => $config->get( 'AppleTouchIcon' )
3332                         ] );
3333                 }
3334
3335                 if ( $config->get( 'Favicon' ) !== false ) {
3336                         $tags['favicon'] = Html::element( 'link', [
3337                                 'rel' => 'shortcut icon',
3338                                 'href' => $config->get( 'Favicon' )
3339                         ] );
3340                 }
3341
3342                 # OpenSearch description link
3343                 $tags['opensearch'] = Html::element( 'link', [
3344                         'rel' => 'search',
3345                         'type' => 'application/opensearchdescription+xml',
3346                         'href' => wfScript( 'opensearch_desc' ),
3347                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3348                 ] );
3349
3350                 # Real Simple Discovery link, provides auto-discovery information
3351                 # for the MediaWiki API (and potentially additional custom API
3352                 # support such as WordPress or Twitter-compatible APIs for a
3353                 # blogging extension, etc)
3354                 $tags['rsd'] = Html::element( 'link', [
3355                         'rel' => 'EditURI',
3356                         'type' => 'application/rsd+xml',
3357                         // Output a protocol-relative URL here if $wgServer is protocol-relative.
3358                         // Whether RSD accepts relative or protocol-relative URLs is completely
3359                         // undocumented, though.
3360                         'href' => wfExpandUrl( wfAppendQuery(
3361                                 wfScript( 'api' ),
3362                                 [ 'action' => 'rsd' ] ),
3363                                 PROTO_RELATIVE
3364                         ),
3365                 ] );
3366
3367                 # Language variants
3368                 if ( !$config->get( 'DisableLangConversion' ) ) {
3369                         $lang = $this->getTitle()->getPageLanguage();
3370                         if ( $lang->hasVariants() ) {
3371                                 $variants = $lang->getVariants();
3372                                 foreach ( $variants as $variant ) {
3373                                         $tags["variant-$variant"] = Html::element( 'link', [
3374                                                 'rel' => 'alternate',
3375                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3376                                                 'href' => $this->getTitle()->getLocalURL(
3377                                                         [ 'variant' => $variant ] )
3378                                                 ]
3379                                         );
3380                                 }
3381                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3382                                 $tags["variant-x-default"] = Html::element( 'link', [
3383                                         'rel' => 'alternate',
3384                                         'hreflang' => 'x-default',
3385                                         'href' => $this->getTitle()->getLocalURL() ] );
3386                         }
3387                 }
3388
3389                 # Copyright
3390                 if ( $this->copyrightUrl !== null ) {
3391                         $copyright = $this->copyrightUrl;
3392                 } else {
3393                         $copyright = '';
3394                         if ( $config->get( 'RightsPage' ) ) {
3395                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3396
3397                                 if ( $copy ) {
3398                                         $copyright = $copy->getLocalURL();
3399                                 }
3400                         }
3401
3402                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3403                                 $copyright = $config->get( 'RightsUrl' );
3404                         }
3405                 }
3406
3407                 if ( $copyright ) {
3408                         $tags['copyright'] = Html::element( 'link', [
3409                                 'rel' => 'license',
3410                                 'href' => $copyright ]
3411                         );
3412                 }
3413
3414                 # Feeds
3415                 if ( $config->get( 'Feed' ) ) {
3416                         $feedLinks = [];
3417
3418                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3419                                 # Use the page name for the title.  In principle, this could
3420                                 # lead to issues with having the same name for different feeds
3421                                 # corresponding to the same page, but we can't avoid that at
3422                                 # this low a level.
3423
3424                                 $feedLinks[] = $this->feedLink(
3425                                         $format,
3426                                         $link,
3427                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3428                                         $this->msg(
3429                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3430                                         )->text()
3431                                 );
3432                         }
3433
3434                         # Recent changes feed should appear on every page (except recentchanges,
3435                         # that would be redundant). Put it after the per-page feed to avoid
3436                         # changing existing behavior. It's still available, probably via a
3437                         # menu in your browser. Some sites might have a different feed they'd
3438                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3439                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3440                         # If so, use it instead.
3441                         $sitename = $config->get( 'Sitename' );
3442                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3443                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3444                                         // Note, this->feedLink escapes the url.
3445                                         $feedLinks[] = $this->feedLink(
3446                                                 $type,
3447                                                 $feedUrl,
3448                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3449                                         );
3450                                 }
3451                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3452                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3453                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3454                                         $feedLinks[] = $this->feedLink(
3455                                                 $format,
3456                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3457                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3458                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3459                                         );
3460                                 }
3461                         }
3462
3463                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3464                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3465                         # use OutputPage::addFeedLink() instead.
3466                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3467
3468                         $tags += $feedLinks;
3469                 }
3470
3471                 # Canonical URL
3472                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3473                         if ( $canonicalUrl !== false ) {
3474                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3475                         } else {
3476                                 if ( $this->isArticleRelated() ) {
3477                                         // This affects all requests where "setArticleRelated" is true. This is
3478                                         // typically all requests that show content (query title, curid, oldid, diff),
3479                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3480                                         // It does not apply to File pages and Special pages.
3481                                         // 'history' and 'info' actions address page metadata rather than the page
3482                                         // content itself, so they may not be canonicalized to the view page url.
3483                                         // TODO: this ought to be better encapsulated in the Action class.
3484                                         $action = Action::getActionName( $this->getContext() );
3485                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3486                                                 $query = "action={$action}";
3487                                         } else {
3488                                                 $query = '';
3489                                         }
3490                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3491                                 } else {
3492                                         $reqUrl = $this->getRequest()->getRequestURL();
3493                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3494                                 }
3495                         }
3496                 }
3497                 if ( $canonicalUrl !== false ) {
3498                         $tags[] = Html::element( 'link', [
3499                                 'rel' => 'canonical',
3500                                 'href' => $canonicalUrl
3501                         ] );
3502                 }
3503
3504                 // Allow extensions to add, remove and/or otherwise manipulate these links
3505                 // If you want only to *add* <head> links, please use the addHeadItem()
3506                 // (or addHeadItems() for multiple items) method instead.
3507                 // This hook is provided as a last resort for extensions to modify these
3508                 // links before the output is sent to client.
3509                 Hooks::run( 'OutputPageAfterGetHeadLinksArray', [ &$tags, $this ] );
3510
3511                 return $tags;
3512         }
3513
3514         /**
3515          * Generate a "<link rel/>" for a feed.
3516          *
3517          * @param string $type Feed type
3518          * @param string $url URL to the feed
3519          * @param string $text Value of the "title" attribute
3520          * @return string HTML fragment
3521          */
3522         private function feedLink( $type, $url, $text ) {
3523                 return Html::element( 'link', [
3524                         'rel' => 'alternate',
3525                         'type' => "application/$type+xml",
3526                         'title' => $text,
3527                         'href' => $url ]
3528                 );
3529         }
3530
3531         /**
3532          * Add a local or specified stylesheet, with the given media options.
3533          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3534          *
3535          * @param string $style URL to the file
3536          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3537          * @param string $condition For IE conditional comments, specifying an IE version
3538          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3539          */
3540         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3541                 $options = [];
3542                 if ( $media ) {
3543                         $options['media'] = $media;
3544                 }
3545                 if ( $condition ) {
3546                         $options['condition'] = $condition;
3547                 }
3548                 if ( $dir ) {
3549                         $options['dir'] = $dir;
3550                 }
3551                 $this->styles[$style] = $options;
3552         }
3553
3554         /**
3555          * Adds inline CSS styles
3556          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3557          *
3558          * @param mixed $style_css Inline CSS
3559          * @param string $flip Set to 'flip' to flip the CSS if needed
3560          */
3561         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3562                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3563                         # If wanted, and the interface is right-to-left, flip the CSS
3564                         $style_css = CSSJanus::transform( $style_css, true, false );
3565                 }
3566                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3567         }
3568
3569         /**
3570          * Build exempt modules and legacy non-ResourceLoader styles.
3571          *
3572          * @return string|WrappedStringList HTML
3573          */
3574         protected function buildExemptModules() {
3575                 $chunks = [];
3576                 // Things that go after the ResourceLoaderDynamicStyles marker
3577                 $append = [];
3578
3579                 // We want site, private and user styles to override dynamically added styles from
3580                 // general modules, but we want dynamically added styles to override statically added
3581                 // style modules. So the order has to be:
3582                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3583                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3584                 // - ResourceLoaderDynamicStyles marker
3585                 // - site/private/user styles
3586
3587                 // Add legacy styles added through addStyle()/addInlineStyle() here
3588                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3589
3590                 $chunks[] = Html::element(
3591                         'meta',
3592                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3593                 );
3594
3595                 $separateReq = [ 'site.styles', 'user.styles' ];
3596                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3597                         // Combinable modules
3598                         $chunks[] = $this->makeResourceLoaderLink(
3599                                 array_diff( $moduleNames, $separateReq ),
3600                                 ResourceLoaderModule::TYPE_STYLES
3601                         );
3602
3603                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3604                                 // These require their own dedicated request in order to support "@import"
3605                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3606                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3607                                         ResourceLoaderModule::TYPE_STYLES
3608                                 );
3609                         }
3610                 }
3611
3612                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3613         }
3614
3615         /**
3616          * @return array
3617          */
3618         public function buildCssLinksArray() {
3619                 $links = [];
3620
3621                 foreach ( $this->styles as $file => $options ) {
3622                         $link = $this->styleLink( $file, $options );
3623                         if ( $link ) {
3624                                 $links[$file] = $link;
3625                         }
3626                 }
3627                 return $links;
3628         }
3629
3630         /**
3631          * Generate \<link\> tags for stylesheets
3632          *
3633          * @param string $style URL to the file
3634          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3635          * @return string HTML fragment
3636          */
3637         protected function styleLink( $style, array $options ) {
3638                 if ( isset( $options['dir'] ) ) {
3639                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3640                                 return '';
3641                         }
3642                 }
3643
3644                 if ( isset( $options['media'] ) ) {
3645                         $media = self::transformCssMedia( $options['media'] );
3646                         if ( is_null( $media ) ) {
3647                                 return '';
3648                         }
3649                 } else {
3650                         $media = 'all';
3651                 }
3652
3653                 if ( substr( $style, 0, 1 ) == '/' ||
3654                         substr( $style, 0, 5 ) == 'http:' ||
3655                         substr( $style, 0, 6 ) == 'https:' ) {
3656                         $url = $style;
3657                 } else {
3658                         $config = $this->getConfig();
3659                         // Append file hash as query parameter
3660                         $url = self::transformResourcePath(
3661                                 $config,
3662                                 $config->get( 'StylePath' ) . '/' . $style
3663                         );
3664                 }
3665
3666                 $link = Html::linkedStyle( $url, $media );
3667
3668                 if ( isset( $options['condition'] ) ) {
3669                         $condition = htmlspecialchars( $options['condition'] );
3670                         $link = "<!--[if $condition]>$link<![endif]-->";
3671                 }
3672                 return $link;
3673         }
3674
3675         /**
3676          * Transform path to web-accessible static resource.
3677          *
3678          * This is used to add a validation hash as query string.
3679          * This aids various behaviors:
3680          *
3681          * - Put long Cache-Control max-age headers on responses for improved
3682          *   cache performance.
3683          * - Get the correct version of a file as expected by the current page.
3684          * - Instantly get the updated version of a file after deployment.
3685          *
3686          * Avoid using this for urls included in HTML as otherwise clients may get different
3687          * versions of a resource when navigating the site depending on when the page was cached.
3688          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3689          * an external stylesheet).
3690          *
3691          * @since 1.27
3692          * @param Config $config
3693          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3694          * @return string URL
3695          */
3696         public static function transformResourcePath( Config $config, $path ) {
3697                 global $IP;
3698
3699                 $localDir = $IP;
3700                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3701                 if ( $remotePathPrefix === '' ) {
3702                         // The configured base path is required to be empty string for
3703                         // wikis in the domain root
3704                         $remotePath = '/';
3705                 } else {
3706                         $remotePath = $remotePathPrefix;
3707                 }
3708                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3709                         // - Path is outside wgResourceBasePath, ignore.
3710                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3711                         return $path;
3712                 }
3713                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3714                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3715                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3716                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3717                 $uploadPath = $config->get( 'UploadPath' );
3718                 if ( strpos( $path, $uploadPath ) === 0 ) {
3719                         $localDir = $config->get( 'UploadDirectory' );
3720                         $remotePathPrefix = $remotePath = $uploadPath;
3721                 }
3722
3723                 $path = RelPath::getRelativePath( $path, $remotePath );
3724                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3725         }
3726
3727         /**
3728          * Utility method for transformResourceFilePath().
3729          *
3730          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3731          *
3732          * @since 1.27
3733          * @param string $remotePathPrefix URL path prefix that points to $localPath
3734          * @param string $localPath File directory exposed at $remotePath
3735          * @param string $file Path to target file relative to $localPath
3736          * @return string URL
3737          */
3738         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3739                 $hash = md5_file( "$localPath/$file" );
3740                 if ( $hash === false ) {
3741                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3742                         $hash = '';
3743                 }
3744                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3745         }
3746
3747         /**
3748          * Transform "media" attribute based on request parameters
3749          *
3750          * @param string $media Current value of the "media" attribute
3751          * @return string Modified value of the "media" attribute, or null to skip
3752          * this stylesheet
3753          */
3754         public static function transformCssMedia( $media ) {
3755                 global $wgRequest;
3756
3757                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3758                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3759
3760                 // Switch in on-screen display for media testing
3761                 $switches = [
3762                         'printable' => 'print',
3763                         'handheld' => 'handheld',
3764                 ];
3765                 foreach ( $switches as $switch => $targetMedia ) {
3766                         if ( $wgRequest->getBool( $switch ) ) {
3767                                 if ( $media == $targetMedia ) {
3768                                         $media = '';
3769                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3770                                         /* This regex will not attempt to understand a comma-separated media_query_list
3771                                          *
3772                                          * Example supported values for $media:
3773                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3774                                          * Example NOT supported value for $media:
3775                                          * '3d-glasses, screen, print and resolution > 90dpi'
3776                                          *
3777                                          * If it's a print request, we never want any kind of screen stylesheets
3778                                          * If it's a handheld request (currently the only other choice with a switch),
3779                                          * we don't want simple 'screen' but we might want screen queries that
3780                                          * have a max-width or something, so we'll pass all others on and let the
3781                                          * client do the query.
3782                                          */
3783                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3784                                                 return null;
3785                                         }
3786                                 }
3787                         }
3788                 }
3789
3790                 return $media;
3791         }
3792
3793         /**
3794          * Add a wikitext-formatted message to the output.
3795          * This is equivalent to:
3796          *
3797          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3798          */
3799         public function addWikiMsg( /*...*/ ) {
3800                 $args = func_get_args();
3801                 $name = array_shift( $args );
3802                 $this->addWikiMsgArray( $name, $args );
3803         }
3804
3805         /**
3806          * Add a wikitext-formatted message to the output.
3807          * Like addWikiMsg() except the parameters are taken as an array
3808          * instead of a variable argument list.
3809          *
3810          * @param string $name
3811          * @param array $args
3812          */
3813         public function addWikiMsgArray( $name, $args ) {
3814                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3815         }
3816
3817         /**
3818          * This function takes a number of message/argument specifications, wraps them in
3819          * some overall structure, and then parses the result and adds it to the output.
3820          *
3821          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3822          * and so on. The subsequent arguments may be either
3823          * 1) strings, in which case they are message names, or
3824          * 2) arrays, in which case, within each array, the first element is the message
3825          *    name, and subsequent elements are the parameters to that message.
3826          *
3827          * Don't use this for messages that are not in the user's interface language.
3828          *
3829          * For example:
3830          *
3831          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3832          *
3833          * Is equivalent to:
3834          *
3835          *    $wgOut->addWikiText( "<div class='error'>\n"
3836          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3837          *
3838          * The newline after the opening div is needed in some wikitext. See T21226.
3839          *
3840          * @param string $wrap
3841          */
3842         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3843                 $msgSpecs = func_get_args();
3844                 array_shift( $msgSpecs );
3845                 $msgSpecs = array_values( $msgSpecs );
3846                 $s = $wrap;
3847                 foreach ( $msgSpecs as $n => $spec ) {
3848                         if ( is_array( $spec ) ) {
3849                                 $args = $spec;
3850                                 $name = array_shift( $args );
3851                                 if ( isset( $args['options'] ) ) {
3852                                         unset( $args['options'] );
3853                                         wfDeprecated(
3854                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3855                                                 '1.20'
3856                                         );
3857                                 }
3858                         } else {
3859                                 $args = [];
3860                                 $name = $spec;
3861                         }
3862                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3863                 }
3864                 $this->addWikiText( $s );
3865         }
3866
3867         /**
3868          * Whether the output has a table of contents
3869          * @return bool
3870          * @since 1.22
3871          */
3872         public function isTOCEnabled() {
3873                 return $this->mEnableTOC;
3874         }
3875
3876         /**
3877          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3878          * @param bool $flag
3879          * @since 1.23
3880          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3881          */
3882         public function enableSectionEditLinks( $flag = true ) {
3883                 wfDeprecated( __METHOD__, '1.31' );
3884         }
3885
3886         /**
3887          * @return bool
3888          * @since 1.23
3889          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3890          */
3891         public function sectionEditLinksEnabled() {
3892                 wfDeprecated( __METHOD__, '1.31' );
3893                 return true;
3894         }
3895
3896         /**
3897          * Helper function to setup the PHP implementation of OOUI to use in this request.
3898          *
3899          * @since 1.26
3900          * @param String $skinName The Skin name to determine the correct OOUI theme
3901          * @param String $dir Language direction
3902          */
3903         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
3904                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
3905                 $theme = $themes[$skinName] ?? $themes['default'];
3906                 // For example, 'OOUI\WikimediaUITheme'.
3907                 $themeClass = "OOUI\\{$theme}Theme";
3908                 OOUI\Theme::setSingleton( new $themeClass() );
3909                 OOUI\Element::setDefaultDir( $dir );
3910         }
3911
3912         /**
3913          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3914          * MediaWiki and this OutputPage instance.
3915          *
3916          * @since 1.25
3917          */
3918         public function enableOOUI() {
3919                 self::setupOOUI(
3920                         strtolower( $this->getSkin()->getSkinName() ),
3921                         $this->getLanguage()->getDir()
3922                 );
3923                 $this->addModuleStyles( [
3924                         'oojs-ui-core.styles',
3925                         'oojs-ui.styles.indicators',
3926                         'oojs-ui.styles.textures',
3927                         'mediawiki.widgets.styles',
3928                         'oojs-ui.styles.icons-content',
3929                         'oojs-ui.styles.icons-alerts',
3930                         'oojs-ui.styles.icons-interactions',
3931                 ] );
3932         }
3933
3934         /**
3935          * Add Link headers for preloading the wiki's logo.
3936          *
3937          * @since 1.26
3938          */
3939         protected function addLogoPreloadLinkHeaders() {
3940                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
3941
3942                 $tags = [];
3943                 $logosPerDppx = [];
3944                 $logos = [];
3945
3946                 if ( !is_array( $logo ) ) {
3947                         // No media queries required if we only have one variant
3948                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
3949                         return;
3950                 }
3951
3952                 if ( isset( $logo['svg'] ) ) {
3953                         // No media queries required if we only have a 1x and svg variant
3954                         // because all preload-capable browsers support SVGs
3955                         $this->addLinkHeader( '<' . $logo['svg'] . '>;rel=preload;as=image' );
3956                         return;
3957                 }
3958
3959                 foreach ( $logo as $dppx => $src ) {
3960                         // Keys are in this format: "1.5x"
3961                         $dppx = substr( $dppx, 0, -1 );
3962                         $logosPerDppx[$dppx] = $src;
3963                 }
3964
3965                 // Because PHP can't have floats as array keys
3966                 uksort( $logosPerDppx, function ( $a , $b ) {
3967                         $a = floatval( $a );
3968                         $b = floatval( $b );
3969                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
3970                         return $a <=> $b;
3971                 } );
3972
3973                 foreach ( $logosPerDppx as $dppx => $src ) {
3974                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
3975                 }
3976
3977                 $logosCount = count( $logos );
3978                 // Logic must match ResourceLoaderSkinModule:
3979                 // - 1x applies to resolution < 1.5dppx
3980                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
3981                 // - 2x applies to resolution >= 2dppx
3982                 // Note that min-resolution and max-resolution are both inclusive.
3983                 for ( $i = 0; $i < $logosCount; $i++ ) {
3984                         if ( $i === 0 ) {
3985                                 // Smallest dppx
3986                                 // min-resolution is ">=" (larger than or equal to)
3987                                 // "not min-resolution" is essentially "<"
3988                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
3989                         } elseif ( $i !== $logosCount - 1 ) {
3990                                 // In between
3991                                 // Media query expressions can only apply "not" to the entire expression
3992                                 // (e.g. can't express ">= 1.5 and not >= 2).
3993                                 // Workaround: Use <= 1.9999 in place of < 2.
3994                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
3995                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
3996                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
3997                         } else {
3998                                 // Largest dppx
3999                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
4000                         }
4001
4002                         $this->addLinkHeader(
4003                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
4004                         );
4005                 }
4006         }
4007
4008         /**
4009          * Get (and set if not yet set) the CSP nonce.
4010          *
4011          * This value needs to be included in any <script> tags on the
4012          * page.
4013          *
4014          * @return string|bool Nonce or false to mean don't output nonce
4015          * @since 1.32
4016          */
4017         public function getCSPNonce() {
4018                 if ( !ContentSecurityPolicy::isNonceRequired( $this->getConfig() ) ) {
4019                         return false;
4020                 }
4021                 if ( $this->CSPNonce === null ) {
4022                         // XXX It might be expensive to generate randomness
4023                         // on every request, on Windows.
4024                         $rand = random_bytes( 15 );
4025                         $this->CSPNonce = base64_encode( $rand );
4026                 }
4027                 return $this->CSPNonce;
4028         }
4029 }