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          * Add a new \<link\> with "rel" attribute set to "meta"
 408          *
 409          * @param array $linkarr Associative array mapping attribute names to their
 410          *                 values, both keys and values will be escaped, and the
 411          *                 "rel" attribute will be automatically added
 412          */
 413         function addMetadataLink( array $linkarr ) {
 414                 $linkarr['rel'] = $this->getMetadataAttribute();
 415                 $this->addLink( $linkarr );
 416         }
 417
 418         /**
 419          * Set the URL to be used for the <link rel=canonical>. This should be used
 420          * in preference to addLink(), to avoid duplicate link tags.
 421          * @param string $url
 422          */
 423         function setCanonicalUrl( $url ) {
 424                 $this->mCanonicalUrl = $url;
 425         }
 426
 427         /**
 428          * Returns the URL to be used for the <link rel=canonical> if
 429          * one is set.
 430          *
 431          * @since 1.25
 432          * @return bool|string
 433          */
 434         public function getCanonicalUrl() {
 435                 return $this->mCanonicalUrl;
 436         }
 437
 438         /**
 439          * Get the value of the "rel" attribute for metadata links
 440          *
 441          * @return string
 442          */
 443         public function getMetadataAttribute() {
 444                 # note: buggy CC software only reads first "meta" link
 445                 static $haveMeta = false;
 446                 if ( $haveMeta ) {
 447                         return 'alternate meta';
 448                 } else {
 449                         $haveMeta = true;
 450                         return 'meta';
 451                 }
 452         }
 453
 454         /**
 455          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 456          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 457          * if possible.
 458          *
 459          * @param string $script Raw HTML
 460          */
 461         function addScript( $script ) {
 462                 $this->mScripts .= $script;
 463         }
 464
 465         /**
 466          * Add a JavaScript file to be loaded as `<script>` on this page.
 467          *
 468          * Internal use only. Use OutputPage::addModules() if possible.
 469          *
 470          * @param string $file URL to file (absolute path, protocol-relative, or full url)
 471          * @param string|null $unused Previously used to change the cache-busting query parameter
 472          */
 473         public function addScriptFile( $file, $unused = null ) {
 474                 if ( substr( $file, 0, 1 ) !== '/' && !preg_match( '#^[a-z]*://#i', $file ) ) {
 475                         // This is not an absolute path, protocol-relative url, or full scheme url,
 476                         // presumed to be an old call intended to include a file from /w/skins/common,
 477                         // which doesn't exist anymore as of MediaWiki 1.24 per T71277. Ignore.
 478                         wfDeprecated( __METHOD__, '1.24' );
 479                         return;
 480                 }
 481                 $this->addScript( Html::linkedScript( $file, $this->getCSPNonce() ) );
 482         }
 483
 484         /**
 485          * Add a self-contained script tag with the given contents
 486          * Internal use only. Use OutputPage::addModules() if possible.
 487          *
 488          * @param string $script JavaScript text, no script tags
 489          */
 490         public function addInlineScript( $script ) {
 491                 $this->mScripts .= Html::inlineScript( "\n$script\n", $this->getCSPNonce() ) . "\n";
 492         }
 493
 494         /**
 495          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 496          * which are no longer registered (eg a page is cached before an extension is disabled)
 497          * @param array $modules
 498          * @param string|null $position Unused
 499          * @param string $type
 500          * @return array
 501          */
 502         protected function filterModules( array $modules, $position = null,
 503                 $type = ResourceLoaderModule::TYPE_COMBINED
 504         ) {
 505                 $resourceLoader = $this->getResourceLoader();
 506                 $filteredModules = [];
 507                 foreach ( $modules as $val ) {
 508                         $module = $resourceLoader->getModule( $val );
 509                         if ( $module instanceof ResourceLoaderModule
 510                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 511                         ) {
 512                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 513                                         $this->warnModuleTargetFilter( $module->getName() );
 514                                         continue;
 515                                 }
 516                                 $filteredModules[] = $val;
 517                         }
 518                 }
 519                 return $filteredModules;
 520         }
 521
 522         private function warnModuleTargetFilter( $moduleName ) {
 523                 static $warnings = [];
 524                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 525                         return;
 526                 }
 527                 $warnings[$this->mTarget][$moduleName] = true;
 528                 $this->getResourceLoader()->getLogger()->debug(
 529                         'Module "{module}" not loadable on target "{target}".',
 530                         [
 531                                 'module' => $moduleName,
 532                                 'target' => $this->mTarget,
 533                         ]
 534                 );
 535         }
 536
 537         /**
 538          * Get the list of modules to include on this page
 539          *
 540          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 541          * @param string|null $position Unused
 542          * @param string $param
 543          * @param string $type
 544          * @return array Array of module names
 545          */
 546         public function getModules( $filter = false, $position = null, $param = 'mModules',
 547                 $type = ResourceLoaderModule::TYPE_COMBINED
 548         ) {
 549                 $modules = array_values( array_unique( $this->$param ) );
 550                 return $filter
 551                         ? $this->filterModules( $modules, null, $type )
 552                         : $modules;
 553         }
 554
 555         /**
 556          * Load one or more ResourceLoader modules on this page.
 557          *
 558          * @param string|array $modules Module name (string) or array of module names
 559          */
 560         public function addModules( $modules ) {
 561                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 562         }
 563
 564         /**
 565          * Get the list of script-only modules to load on this page.
 566          *
 567          * @param bool $filter
 568          * @param string|null $position Unused
 569          * @return array Array of module names
 570          */
 571         public function getModuleScripts( $filter = false, $position = null ) {
 572                 return $this->getModules( $filter, null, 'mModuleScripts',
 573                         ResourceLoaderModule::TYPE_SCRIPTS
 574                 );
 575         }
 576
 577         /**
 578          * Load the scripts of one or more ResourceLoader modules, on this page.
 579          *
 580          * This method exists purely to provide the legacy behaviour of loading
 581          * a module's scripts in the global scope, and without dependency resolution.
 582          * See <https://phabricator.wikimedia.org/T188689>.
 583          *
 584          * @deprecated since 1.31 Use addModules() instead.
 585          * @param string|array $modules Module name (string) or array of module names
 586          */
 587         public function addModuleScripts( $modules ) {
 588                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 589         }
 590
 591         /**
 592          * Get the list of style-only modules to load on this page.
 593          *
 594          * @param bool $filter
 595          * @param string|null $position Unused
 596          * @return array Array of module names
 597          */
 598         public function getModuleStyles( $filter = false, $position = null ) {
 599                 return $this->getModules( $filter, null, 'mModuleStyles',
 600                         ResourceLoaderModule::TYPE_STYLES
 601                 );
 602         }
 603
 604         /**
 605          * Load the styles of one or more ResourceLoader modules on this page.
 606          *
 607          * Module styles added through this function will be loaded as a stylesheet,
 608          * using a standard `<link rel=stylesheet>` HTML tag, rather than as a combined
 609          * Javascript and CSS package. Thus, they will even load when JavaScript is disabled.
 610          *
 611          * @param string|array $modules Module name (string) or array of module names
 612          */
 613         public function addModuleStyles( $modules ) {
 614                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 615         }
 616
 617         /**
 618          * @return null|string ResourceLoader target
 619          */
 620         public function getTarget() {
 621                 return $this->mTarget;
 622         }
 623
 624         /**
 625          * Sets ResourceLoader target for load.php links. If null, will be omitted
 626          *
 627          * @param string|null $target
 628          */
 629         public function setTarget( $target ) {
 630                 $this->mTarget = $target;
 631         }
 632
 633         /**
 634          * Add a mapping from a LinkTarget to a Content, for things like page preview.
 635          * @see self::addContentOverrideCallback()
 636          * @since 1.32
 637          * @param LinkTarget $target
 638          * @param Content $content
 639          */
 640         public function addContentOverride( LinkTarget $target, Content $content ) {
 641                 if ( !$this->contentOverrides ) {
 642                         // Register a callback for $this->contentOverrides on the first call
 643                         $this->addContentOverrideCallback( function ( LinkTarget $target ) {
 644                                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 645                                 return $this->contentOverrides[$key] ?? null;
 646                         } );
 647                 }
 648
 649                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 650                 $this->contentOverrides[$key] = $content;
 651         }
 652
 653         /**
 654          * Add a callback for mapping from a Title to a Content object, for things
 655          * like page preview.
 656          * @see ResourceLoaderContext::getContentOverrideCallback()
 657          * @since 1.32
 658          * @param callable $callback
 659          */
 660         public function addContentOverrideCallback( callable $callback ) {
 661                 $this->contentOverrideCallbacks[] = $callback;
 662         }
 663
 664         /**
 665          * Get an array of head items
 666          *
 667          * @return array
 668          */
 669         function getHeadItemsArray() {
 670                 return $this->mHeadItems;
 671         }
 672
 673         /**
 674          * Add or replace a head item to the output
 675          *
 676          * Whenever possible, use more specific options like ResourceLoader modules,
 677          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 678          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 679          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 680          * This would be your very LAST fallback.
 681          *
 682          * @param string $name Item name
 683          * @param string $value Raw HTML
 684          */
 685         public function addHeadItem( $name, $value ) {
 686                 $this->mHeadItems[$name] = $value;
 687         }
 688
 689         /**
 690          * Add one or more head items to the output
 691          *
 692          * @since 1.28
 693          * @param string|string[] $values Raw HTML
 694          */
 695         public function addHeadItems( $values ) {
 696                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 697         }
 698
 699         /**
 700          * Check if the header item $name is already set
 701          *
 702          * @param string $name Item name
 703          * @return bool
 704          */
 705         public function hasHeadItem( $name ) {
 706                 return isset( $this->mHeadItems[$name] );
 707         }
 708
 709         /**
 710          * Add a class to the <body> element
 711          *
 712          * @since 1.30
 713          * @param string|string[] $classes One or more classes to add
 714          */
 715         public function addBodyClasses( $classes ) {
 716                 $this->mAdditionalBodyClasses = array_merge( $this->mAdditionalBodyClasses, (array)$classes );
 717         }
 718
 719         /**
 720          * Set whether the output should only contain the body of the article,
 721          * without any skin, sidebar, etc.
 722          * Used e.g. when calling with "action=render".
 723          *
 724          * @param bool $only Whether to output only the body of the article
 725          */
 726         public function setArticleBodyOnly( $only ) {
 727                 $this->mArticleBodyOnly = $only;
 728         }
 729
 730         /**
 731          * Return whether the output will contain only the body of the article
 732          *
 733          * @return bool
 734          */
 735         public function getArticleBodyOnly() {
 736                 return $this->mArticleBodyOnly;
 737         }
 738
 739         /**
 740          * Set an additional output property
 741          * @since 1.21
 742          *
 743          * @param string $name
 744          * @param mixed $value
 745          */
 746         public function setProperty( $name, $value ) {
 747                 $this->mProperties[$name] = $value;
 748         }
 749
 750         /**
 751          * Get an additional output property
 752          * @since 1.21
 753          *
 754          * @param string $name
 755          * @return mixed Property value or null if not found
 756          */
 757         public function getProperty( $name ) {
 758                 return $this->mProperties[$name] ?? null;
 759         }
 760
 761         /**
 762          * checkLastModified tells the client to use the client-cached page if
 763          * possible. If successful, the OutputPage is disabled so that
 764          * any future call to OutputPage->output() have no effect.
 765          *
 766          * Side effect: sets mLastModified for Last-Modified header
 767          *
 768          * @param string $timestamp
 769          *
 770          * @return bool True if cache-ok headers was sent.
 771          */
 772         public function checkLastModified( $timestamp ) {
 773                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 774                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 775                         return false;
 776                 }
 777                 $config = $this->getConfig();
 778                 if ( !$config->get( 'CachePages' ) ) {
 779                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 780                         return false;
 781                 }
 782
 783                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 784                 $modifiedTimes = [
 785                         'page' => $timestamp,
 786                         'user' => $this->getUser()->getTouched(),
 787                         'epoch' => $config->get( 'CacheEpoch' )
 788                 ];
 789                 if ( $config->get( 'UseSquid' ) ) {
 790                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, $this->getCdnCacheEpoch(
 791                                 time(),
 792                                 $config->get( 'SquidMaxage' )
 793                         ) );
 794                 }
 795                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 796
 797                 $maxModified = max( $modifiedTimes );
 798                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 799
 800                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 801                 if ( $clientHeader === false ) {
 802                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 803                         return false;
 804                 }
 805
 806                 # IE sends sizes after the date like this:
 807                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 808                 # this breaks strtotime().
 809                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 810
 811                 Wikimedia\suppressWarnings(); // E_STRICT system time bitching
 812                 $clientHeaderTime = strtotime( $clientHeader );
 813                 Wikimedia\restoreWarnings();
 814                 if ( !$clientHeaderTime ) {
 815                         wfDebug( __METHOD__
 816                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 817                         return false;
 818                 }
 819                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 820
 821                 # Make debug info
 822                 $info = '';
 823                 foreach ( $modifiedTimes as $name => $value ) {
 824                         if ( $info !== '' ) {
 825                                 $info .= ', ';
 826                         }
 827                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 828                 }
 829
 830                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 831                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 832                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 833                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 834                 if ( $clientHeaderTime < $maxModified ) {
 835                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 836                         return false;
 837                 }
 838
 839                 # Not modified
 840                 # Give a 304 Not Modified response code and disable body output
 841                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 842                 ini_set( 'zlib.output_compression', 0 );
 843                 $this->getRequest()->response()->statusHeader( 304 );
 844                 $this->sendCacheControl();
 845                 $this->disable();
 846
 847                 // Don't output a compressed blob when using ob_gzhandler;
 848                 // it's technically against HTTP spec and seems to confuse
 849                 // Firefox when the response gets split over two packets.
 850                 wfClearOutputBuffers();
 851
 852                 return true;
 853         }
 854
 855         /**
 856          * @param int $reqTime Time of request (eg. now)
 857          * @param int $maxAge Cache TTL in seconds
 858          * @return int Timestamp
 859          */
 860         private function getCdnCacheEpoch( $reqTime, $maxAge ) {
 861                 // Ensure Last-Modified is never more than (wgSquidMaxage) in the past,
 862                 // because even if the wiki page content hasn't changed since, static
 863                 // resources may have changed (skin HTML, interface messages, urls, etc.)
 864                 // and must roll-over in a timely manner (T46570)
 865                 return $reqTime - $maxAge;
 866         }
 867
 868         /**
 869          * Override the last modified timestamp
 870          *
 871          * @param string $timestamp New timestamp, in a format readable by
 872          *        wfTimestamp()
 873          */
 874         public function setLastModified( $timestamp ) {
 875                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 876         }
 877
 878         /**
 879          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 880          *
 881          * @param string $policy The literal string to output as the contents of
 882          *   the meta tag.  Will be parsed according to the spec and output in
 883          *   standardized form.
 884          * @return null
 885          */
 886         public function setRobotPolicy( $policy ) {
 887                 $policy = Article::formatRobotPolicy( $policy );
 888
 889                 if ( isset( $policy['index'] ) ) {
 890                         $this->setIndexPolicy( $policy['index'] );
 891                 }
 892                 if ( isset( $policy['follow'] ) ) {
 893                         $this->setFollowPolicy( $policy['follow'] );
 894                 }
 895         }
 896
 897         /**
 898          * Set the index policy for the page, but leave the follow policy un-
 899          * touched.
 900          *
 901          * @param string $policy Either 'index' or 'noindex'.
 902          * @return null
 903          */
 904         public function setIndexPolicy( $policy ) {
 905                 $policy = trim( $policy );
 906                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 907                         $this->mIndexPolicy = $policy;
 908                 }
 909         }
 910
 911         /**
 912          * Set the follow policy for the page, but leave the index policy un-
 913          * touched.
 914          *
 915          * @param string $policy Either 'follow' or 'nofollow'.
 916          * @return null
 917          */
 918         public function setFollowPolicy( $policy ) {
 919                 $policy = trim( $policy );
 920                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 921                         $this->mFollowPolicy = $policy;
 922                 }
 923         }
 924
 925         /**
 926          * Set the new value of the "action text", this will be added to the
 927          * "HTML title", separated from it with " - ".
 928          *
 929          * @param string $text New value of the "action text"
 930          */
 931         public function setPageTitleActionText( $text ) {
 932                 $this->mPageTitleActionText = $text;
 933         }
 934
 935         /**
 936          * Get the value of the "action text"
 937          *
 938          * @return string
 939          */
 940         public function getPageTitleActionText() {
 941                 return $this->mPageTitleActionText;
 942         }
 943
 944         /**
 945          * "HTML title" means the contents of "<title>".
 946          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 947          *
 948          * @param string|Message $name
 949          */
 950         public function setHTMLTitle( $name ) {
 951                 if ( $name instanceof Message ) {
 952                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 953                 } else {
 954                         $this->mHTMLtitle = $name;
 955                 }
 956         }
 957
 958         /**
 959          * Return the "HTML title", i.e. the content of the "<title>" tag.
 960          *
 961          * @return string
 962          */
 963         public function getHTMLTitle() {
 964                 return $this->mHTMLtitle;
 965         }
 966
 967         /**
 968          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 969          *
 970          * @param Title $t
 971          */
 972         public function setRedirectedFrom( $t ) {
 973                 $this->mRedirectedFrom = $t;
 974         }
 975
 976         /**
 977          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 978          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 979          * but not bad tags like \<script\>. This function automatically sets
 980          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 981          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 982          * good tags like \<i\> will be dropped entirely.
 983          *
 984          * @param string|Message $name
 985          */
 986         public function setPageTitle( $name ) {
 987                 if ( $name instanceof Message ) {
 988                         $name = $name->setContext( $this->getContext() )->text();
 989                 }
 990
 991                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 992                 # but leave "<i>foobar</i>" alone
 993                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 994                 $this->mPageTitle = $nameWithTags;
 995
 996                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 997                 $this->setHTMLTitle(
 998                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 999                                 ->inContentLanguage()
1000                 );
1001         }
1002
1003         /**
1004          * Return the "page title", i.e. the content of the \<h1\> tag.
1005          *
1006          * @return string
1007          */
1008         public function getPageTitle() {
1009                 return $this->mPageTitle;
1010         }
1011
1012         /**
1013          * Set the Title object to use
1014          *
1015          * @param Title $t
1016          */
1017         public function setTitle( Title $t ) {
1018                 $this->getContext()->setTitle( $t );
1019         }
1020
1021         /**
1022          * Replace the subtitle with $str
1023          *
1024          * @param string|Message $str New value of the subtitle. String should be safe HTML.
1025          */
1026         public function setSubtitle( $str ) {
1027                 $this->clearSubtitle();
1028                 $this->addSubtitle( $str );
1029         }
1030
1031         /**
1032          * Add $str to the subtitle
1033          *
1034          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
1035          */
1036         public function addSubtitle( $str ) {
1037                 if ( $str instanceof Message ) {
1038                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
1039                 } else {
1040                         $this->mSubtitle[] = $str;
1041                 }
1042         }
1043
1044         /**
1045          * Build message object for a subtitle containing a backlink to a page
1046          *
1047          * @param Title $title Title to link to
1048          * @param array $query Array of additional parameters to include in the link
1049          * @return Message
1050          * @since 1.25
1051          */
1052         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1053                 if ( $title->isRedirect() ) {
1054                         $query['redirect'] = 'no';
1055                 }
1056                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1057                 return wfMessage( 'backlinksubtitle' )
1058                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1059         }
1060
1061         /**
1062          * Add a subtitle containing a backlink to a page
1063          *
1064          * @param Title $title Title to link to
1065          * @param array $query Array of additional parameters to include in the link
1066          */
1067         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1068                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1069         }
1070
1071         /**
1072          * Clear the subtitles
1073          */
1074         public function clearSubtitle() {
1075                 $this->mSubtitle = [];
1076         }
1077
1078         /**
1079          * Get the subtitle
1080          *
1081          * @return string
1082          */
1083         public function getSubtitle() {
1084                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1085         }
1086
1087         /**
1088          * Set the page as printable, i.e. it'll be displayed with all
1089          * print styles included
1090          */
1091         public function setPrintable() {
1092                 $this->mPrintable = true;
1093         }
1094
1095         /**
1096          * Return whether the page is "printable"
1097          *
1098          * @return bool
1099          */
1100         public function isPrintable() {
1101                 return $this->mPrintable;
1102         }
1103
1104         /**
1105          * Disable output completely, i.e. calling output() will have no effect
1106          */
1107         public function disable() {
1108                 $this->mDoNothing = true;
1109         }
1110
1111         /**
1112          * Return whether the output will be completely disabled
1113          *
1114          * @return bool
1115          */
1116         public function isDisabled() {
1117                 return $this->mDoNothing;
1118         }
1119
1120         /**
1121          * Show an "add new section" link?
1122          *
1123          * @return bool
1124          */
1125         public function showNewSectionLink() {
1126                 return $this->mNewSectionLink;
1127         }
1128
1129         /**
1130          * Forcibly hide the new section link?
1131          *
1132          * @return bool
1133          */
1134         public function forceHideNewSectionLink() {
1135                 return $this->mHideNewSectionLink;
1136         }
1137
1138         /**
1139          * Add or remove feed links in the page header
1140          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1141          * for the new version
1142          * @see addFeedLink()
1143          *
1144          * @param bool $show True: add default feeds, false: remove all feeds
1145          */
1146         public function setSyndicated( $show = true ) {
1147                 if ( $show ) {
1148                         $this->setFeedAppendQuery( false );
1149                 } else {
1150                         $this->mFeedLinks = [];
1151                 }
1152         }
1153
1154         /**
1155          * Add default feeds to the page header
1156          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1157          * for the new version
1158          * @see addFeedLink()
1159          *
1160          * @param string $val Query to append to feed links or false to output
1161          *        default links
1162          */
1163         public function setFeedAppendQuery( $val ) {
1164                 $this->mFeedLinks = [];
1165
1166                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1167                         $query = "feed=$type";
1168                         if ( is_string( $val ) ) {
1169                                 $query .= '&' . $val;
1170                         }
1171                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1172                 }
1173         }
1174
1175         /**
1176          * Add a feed link to the page header
1177          *
1178          * @param string $format Feed type, should be a key of $wgFeedClasses
1179          * @param string $href URL
1180          */
1181         public function addFeedLink( $format, $href ) {
1182                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1183                         $this->mFeedLinks[$format] = $href;
1184                 }
1185         }
1186
1187         /**
1188          * Should we output feed links for this page?
1189          * @return bool
1190          */
1191         public function isSyndicated() {
1192                 return count( $this->mFeedLinks ) > 0;
1193         }
1194
1195         /**
1196          * Return URLs for each supported syndication format for this page.
1197          * @return array Associating format keys with URLs
1198          */
1199         public function getSyndicationLinks() {
1200                 return $this->mFeedLinks;
1201         }
1202
1203         /**
1204          * Will currently always return null
1205          *
1206          * @return null
1207          */
1208         public function getFeedAppendQuery() {
1209                 return $this->mFeedLinksAppendQuery;
1210         }
1211
1212         /**
1213          * Set whether the displayed content is related to the source of the
1214          * corresponding article on the wiki
1215          * Setting true will cause the change "article related" toggle to true
1216          *
1217          * @param bool $v
1218          */
1219         public function setArticleFlag( $v ) {
1220                 $this->mIsarticle = $v;
1221                 if ( $v ) {
1222                         $this->mIsArticleRelated = $v;
1223                 }
1224         }
1225
1226         /**
1227          * Return whether the content displayed page is related to the source of
1228          * the corresponding article on the wiki
1229          *
1230          * @return bool
1231          */
1232         public function isArticle() {
1233                 return $this->mIsarticle;
1234         }
1235
1236         /**
1237          * Set whether this page is related an article on the wiki
1238          * Setting false will cause the change of "article flag" toggle to false
1239          *
1240          * @param bool $v
1241          */
1242         public function setArticleRelated( $v ) {
1243                 $this->mIsArticleRelated = $v;
1244                 if ( !$v ) {
1245                         $this->mIsarticle = false;
1246                 }
1247         }
1248
1249         /**
1250          * Return whether this page is related an article on the wiki
1251          *
1252          * @return bool
1253          */
1254         public function isArticleRelated() {
1255                 return $this->mIsArticleRelated;
1256         }
1257
1258         /**
1259          * Add new language links
1260          *
1261          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1262          *                               (e.g. 'fr:Test page')
1263          */
1264         public function addLanguageLinks( array $newLinkArray ) {
1265                 $this->mLanguageLinks = array_merge( $this->mLanguageLinks, $newLinkArray );
1266         }
1267
1268         /**
1269          * Reset the language links and add new language links
1270          *
1271          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1272          *                               (e.g. 'fr:Test page')
1273          */
1274         public function setLanguageLinks( array $newLinkArray ) {
1275                 $this->mLanguageLinks = $newLinkArray;
1276         }
1277
1278         /**
1279          * Get the list of language links
1280          *
1281          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1282          */
1283         public function getLanguageLinks() {
1284                 return $this->mLanguageLinks;
1285         }
1286
1287         /**
1288          * Add an array of categories, with names in the keys
1289          *
1290          * @param array $categories Mapping category name => sort key
1291          */
1292         public function addCategoryLinks( array $categories ) {
1293                 global $wgContLang;
1294
1295                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1296                         return;
1297                 }
1298
1299                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1300
1301                 # Set all the values to 'normal'.
1302                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1303
1304                 # Mark hidden categories
1305                 foreach ( $res as $row ) {
1306                         if ( isset( $row->pp_value ) ) {
1307                                 $categories[$row->page_title] = 'hidden';
1308                         }
1309                 }
1310
1311                 // Avoid PHP 7.1 warning of passing $this by reference
1312                 $outputPage = $this;
1313                 # Add the remaining categories to the skin
1314                 if ( Hooks::run(
1315                         'OutputPageMakeCategoryLinks',
1316                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1317                 ) {
1318                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1319                         foreach ( $categories as $category => $type ) {
1320                                 // array keys will cast numeric category names to ints, so cast back to string
1321                                 $category = (string)$category;
1322                                 $origcategory = $category;
1323                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1324                                 if ( !$title ) {
1325                                         continue;
1326                                 }
1327                                 $wgContLang->findVariantLink( $category, $title, true );
1328                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1329                                         continue;
1330                                 }
1331                                 $text = $wgContLang->convertHtml( $title->getText() );
1332                                 $this->mCategories[$type][] = $title->getText();
1333                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1334                         }
1335                 }
1336         }
1337
1338         /**
1339          * @param array $categories
1340          * @return bool|IResultWrapper
1341          */
1342         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1343                 # Add the links to a LinkBatch
1344                 $arr = [ NS_CATEGORY => $categories ];
1345                 $lb = new LinkBatch;
1346                 $lb->setArray( $arr );
1347
1348                 # Fetch existence plus the hiddencat property
1349                 $dbr = wfGetDB( DB_REPLICA );
1350                 $fields = array_merge(
1351                         LinkCache::getSelectFields(),
1352                         [ 'page_namespace', 'page_title', 'pp_value' ]
1353                 );
1354
1355                 $res = $dbr->select( [ 'page', 'page_props' ],
1356                         $fields,
1357                         $lb->constructSet( 'page', $dbr ),
1358                         __METHOD__,
1359                         [],
1360                         [ 'page_props' => [ 'LEFT JOIN', [
1361                                 'pp_propname' => 'hiddencat',
1362                                 'pp_page = page_id'
1363                         ] ] ]
1364                 );
1365
1366                 # Add the results to the link cache
1367                 $linkCache = MediaWikiServices::getInstance()->getLinkCache();
1368                 $lb->addResultToCache( $linkCache, $res );
1369
1370                 return $res;
1371         }
1372
1373         /**
1374          * Reset the category links (but not the category list) and add $categories
1375          *
1376          * @param array $categories Mapping category name => sort key
1377          */
1378         public function setCategoryLinks( array $categories ) {
1379                 $this->mCategoryLinks = [];
1380                 $this->addCategoryLinks( $categories );
1381         }
1382
1383         /**
1384          * Get the list of category links, in a 2-D array with the following format:
1385          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1386          * hidden categories) and $link a HTML fragment with a link to the category
1387          * page
1388          *
1389          * @return array
1390          */
1391         public function getCategoryLinks() {
1392                 return $this->mCategoryLinks;
1393         }
1394
1395         /**
1396          * Get the list of category names this page belongs to.
1397          *
1398          * @param string $type The type of categories which should be returned. Possible values:
1399          *  * all: all categories of all types
1400          *  * hidden: only the hidden categories
1401          *  * normal: all categories, except hidden categories
1402          * @return array Array of strings
1403          */
1404         public function getCategories( $type = 'all' ) {
1405                 if ( $type === 'all' ) {
1406                         $allCategories = [];
1407                         foreach ( $this->mCategories as $categories ) {
1408                                 $allCategories = array_merge( $allCategories, $categories );
1409                         }
1410                         return $allCategories;
1411                 }
1412                 if ( !isset( $this->mCategories[$type] ) ) {
1413                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1414                 }
1415                 return $this->mCategories[$type];
1416         }
1417
1418         /**
1419          * Add an array of indicators, with their identifiers as array
1420          * keys and HTML contents as values.
1421          *
1422          * In case of duplicate keys, existing values are overwritten.
1423          *
1424          * @param array $indicators
1425          * @since 1.25
1426          */
1427         public function setIndicators( array $indicators ) {
1428                 $this->mIndicators = $indicators + $this->mIndicators;
1429                 // Keep ordered by key
1430                 ksort( $this->mIndicators );
1431         }
1432
1433         /**
1434          * Get the indicators associated with this page.
1435          *
1436          * The array will be internally ordered by item keys.
1437          *
1438          * @return array Keys: identifiers, values: HTML contents
1439          * @since 1.25
1440          */
1441         public function getIndicators() {
1442                 return $this->mIndicators;
1443         }
1444
1445         /**
1446          * Adds help link with an icon via page indicators.
1447          * Link target can be overridden by a local message containing a wikilink:
1448          * the message key is: lowercase action or special page name + '-helppage'.
1449          * @param string $to Target MediaWiki.org page title or encoded URL.
1450          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1451          * @since 1.25
1452          */
1453         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1454                 $this->addModuleStyles( 'mediawiki.helplink' );
1455                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1456
1457                 if ( $overrideBaseUrl ) {
1458                         $helpUrl = $to;
1459                 } else {
1460                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1461                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1462                 }
1463
1464                 $link = Html::rawElement(
1465                         'a',
1466                         [
1467                                 'href' => $helpUrl,
1468                                 'target' => '_blank',
1469                                 'class' => 'mw-helplink',
1470                         ],
1471                         $text
1472                 );
1473
1474                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1475         }
1476
1477         /**
1478          * Do not allow scripts which can be modified by wiki users to load on this page;
1479          * only allow scripts bundled with, or generated by, the software.
1480          * Site-wide styles are controlled by a config setting, since they can be
1481          * used to create a custom skin/theme, but not user-specific ones.
1482          *
1483          * @todo this should be given a more accurate name
1484          */
1485         public function disallowUserJs() {
1486                 $this->reduceAllowedModules(
1487                         ResourceLoaderModule::TYPE_SCRIPTS,
1488                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1489                 );
1490
1491                 // Site-wide styles are controlled by a config setting, see T73621
1492                 // for background on why. User styles are never allowed.
1493                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1494                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1495                 } else {
1496                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1497                 }
1498                 $this->reduceAllowedModules(
1499                         ResourceLoaderModule::TYPE_STYLES,
1500                         $styleOrigin
1501                 );
1502         }
1503
1504         /**
1505          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1506          * @see ResourceLoaderModule::$origin
1507          * @param string $type ResourceLoaderModule TYPE_ constant
1508          * @return int ResourceLoaderModule ORIGIN_ class constant
1509          */
1510         public function getAllowedModules( $type ) {
1511                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1512                         return min( array_values( $this->mAllowedModules ) );
1513                 } else {
1514                         return $this->mAllowedModules[$type] ?? ResourceLoaderModule::ORIGIN_ALL;
1515                 }
1516         }
1517
1518         /**
1519          * Limit the highest level of CSS/JS untrustworthiness allowed.
1520          *
1521          * If passed the same or a higher level than the current level of untrustworthiness set, the
1522          * level will remain unchanged.
1523          *
1524          * @param string $type
1525          * @param int $level ResourceLoaderModule class constant
1526          */
1527         public function reduceAllowedModules( $type, $level ) {
1528                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1529         }
1530
1531         /**
1532          * Prepend $text to the body HTML
1533          *
1534          * @param string $text HTML
1535          */
1536         public function prependHTML( $text ) {
1537                 $this->mBodytext = $text . $this->mBodytext;
1538         }
1539
1540         /**
1541          * Append $text to the body HTML
1542          *
1543          * @param string $text HTML
1544          */
1545         public function addHTML( $text ) {
1546                 $this->mBodytext .= $text;
1547         }
1548
1549         /**
1550          * Shortcut for adding an Html::element via addHTML.
1551          *
1552          * @since 1.19
1553          *
1554          * @param string $element
1555          * @param array $attribs
1556          * @param string $contents
1557          */
1558         public function addElement( $element, array $attribs = [], $contents = '' ) {
1559                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1560         }
1561
1562         /**
1563          * Clear the body HTML
1564          */
1565         public function clearHTML() {
1566                 $this->mBodytext = '';
1567         }
1568
1569         /**
1570          * Get the body HTML
1571          *
1572          * @return string HTML
1573          */
1574         public function getHTML() {
1575                 return $this->mBodytext;
1576         }
1577
1578         /**
1579          * Get/set the ParserOptions object to use for wikitext parsing
1580          *
1581          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1582          *   current ParserOption object. This parameter is deprecated since 1.31.
1583          * @return ParserOptions
1584          */
1585         public function parserOptions( $options = null ) {
1586                 if ( $options !== null ) {
1587                         wfDeprecated( __METHOD__ . ' with non-null $options', '1.31' );
1588                 }
1589
1590                 if ( $options !== null && !empty( $options->isBogus ) ) {
1591                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1592                         // been changed somehow, and keep it if so.
1593                         $anonPO = ParserOptions::newFromAnon();
1594                         $anonPO->setAllowUnsafeRawHtml( false );
1595                         if ( !$options->matches( $anonPO ) ) {
1596                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1597                                 $options->isBogus = false;
1598                         }
1599                 }
1600
1601                 if ( !$this->mParserOptions ) {
1602                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1603                                 // $wgUser isn't unstubbable yet, so don't try to get a
1604                                 // ParserOptions for it. And don't cache this ParserOptions
1605                                 // either.
1606                                 $po = ParserOptions::newFromAnon();
1607                                 $po->setAllowUnsafeRawHtml( false );
1608                                 $po->isBogus = true;
1609                                 if ( $options !== null ) {
1610                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1611                                 }
1612                                 return $po;
1613                         }
1614
1615                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1616                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1617                 }
1618
1619                 if ( $options !== null && !empty( $options->isBogus ) ) {
1620                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1621                         // thing.
1622                         return wfSetVar( $this->mParserOptions, null, true );
1623                 } else {
1624                         return wfSetVar( $this->mParserOptions, $options );
1625                 }
1626         }
1627
1628         /**
1629          * Set the revision ID which will be seen by the wiki text parser
1630          * for things such as embedded {{REVISIONID}} variable use.
1631          *
1632          * @param int|null $revid An positive integer, or null
1633          * @return mixed Previous value
1634          */
1635         public function setRevisionId( $revid ) {
1636                 $val = is_null( $revid ) ? null : intval( $revid );
1637                 return wfSetVar( $this->mRevisionId, $val );
1638         }
1639
1640         /**
1641          * Get the displayed revision ID
1642          *
1643          * @return int
1644          */
1645         public function getRevisionId() {
1646                 return $this->mRevisionId;
1647         }
1648
1649         /**
1650          * Set the timestamp of the revision which will be displayed. This is used
1651          * to avoid a extra DB call in Skin::lastModified().
1652          *
1653          * @param string|null $timestamp
1654          * @return mixed Previous value
1655          */
1656         public function setRevisionTimestamp( $timestamp ) {
1657                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1658         }
1659
1660         /**
1661          * Get the timestamp of displayed revision.
1662          * This will be null if not filled by setRevisionTimestamp().
1663          *
1664          * @return string|null
1665          */
1666         public function getRevisionTimestamp() {
1667                 return $this->mRevisionTimestamp;
1668         }
1669
1670         /**
1671          * Set the displayed file version
1672          *
1673          * @param File|bool $file
1674          * @return mixed Previous value
1675          */
1676         public function setFileVersion( $file ) {
1677                 $val = null;
1678                 if ( $file instanceof File && $file->exists() ) {
1679                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1680                 }
1681                 return wfSetVar( $this->mFileVersion, $val, true );
1682         }
1683
1684         /**
1685          * Get the displayed file version
1686          *
1687          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1688          */
1689         public function getFileVersion() {
1690                 return $this->mFileVersion;
1691         }
1692
1693         /**
1694          * Get the templates used on this page
1695          *
1696          * @return array (namespace => dbKey => revId)
1697          * @since 1.18
1698          */
1699         public function getTemplateIds() {
1700                 return $this->mTemplateIds;
1701         }
1702
1703         /**
1704          * Get the files used on this page
1705          *
1706          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1707          * @since 1.18
1708          */
1709         public function getFileSearchOptions() {
1710                 return $this->mImageTimeKeys;
1711         }
1712
1713         /**
1714          * Convert wikitext to HTML and add it to the buffer
1715          * Default assumes that the current page title will be used.
1716          *
1717          * @param string $text
1718          * @param bool $linestart Is this the start of a line?
1719          * @param bool $interface Is this text in the user interface language?
1720          * @throws MWException
1721          */
1722         public function addWikiText( $text, $linestart = true, $interface = true ) {
1723                 $title = $this->getTitle(); // Work around E_STRICT
1724                 if ( !$title ) {
1725                         throw new MWException( 'Title is null' );
1726                 }
1727                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1728         }
1729
1730         /**
1731          * Add wikitext with a custom Title object
1732          *
1733          * @param string $text Wikitext
1734          * @param Title &$title
1735          * @param bool $linestart Is this the start of a line?
1736          */
1737         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1738                 $this->addWikiTextTitle( $text, $title, $linestart );
1739         }
1740
1741         /**
1742          * Add wikitext with a custom Title object and tidy enabled.
1743          *
1744          * @param string $text Wikitext
1745          * @param Title &$title
1746          * @param bool $linestart Is this the start of a line?
1747          */
1748         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1749                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1750         }
1751
1752         /**
1753          * Add wikitext with tidy enabled
1754          *
1755          * @param string $text Wikitext
1756          * @param bool $linestart Is this the start of a line?
1757          */
1758         public function addWikiTextTidy( $text, $linestart = true ) {
1759                 $title = $this->getTitle();
1760                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1761         }
1762
1763         /**
1764          * Add wikitext with a custom Title object
1765          *
1766          * @param string $text Wikitext
1767          * @param Title $title
1768          * @param bool $linestart Is this the start of a line?
1769          * @param bool $tidy Whether to use tidy
1770          * @param bool $interface Whether it is an interface message
1771          *   (for example disables conversion)
1772          */
1773         public function addWikiTextTitle( $text, Title $title, $linestart,
1774                 $tidy = false, $interface = false
1775         ) {
1776                 global $wgParser;
1777
1778                 $popts = $this->parserOptions();
1779                 $oldTidy = $popts->setTidy( $tidy );
1780                 $popts->setInterfaceMessage( (bool)$interface );
1781
1782                 $parserOutput = $wgParser->getFreshParser()->parse(
1783                         $text, $title, $popts,
1784                         $linestart, true, $this->mRevisionId
1785                 );
1786
1787                 $popts->setTidy( $oldTidy );
1788
1789                 $this->addParserOutput( $parserOutput, [
1790                         'enableSectionEditLinks' => false,
1791                 ] );
1792         }
1793
1794         /**
1795          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1796          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1797          * and so on.
1798          *
1799          * @since 1.24
1800          * @param ParserOutput $parserOutput
1801          */
1802         public function addParserOutputMetadata( $parserOutput ) {
1803                 $this->mLanguageLinks =
1804                         array_merge( $this->mLanguageLinks, $parserOutput->getLanguageLinks() );
1805                 $this->addCategoryLinks( $parserOutput->getCategories() );
1806                 $this->setIndicators( $parserOutput->getIndicators() );
1807                 $this->mNewSectionLink = $parserOutput->getNewSection();
1808                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1809
1810                 if ( !$parserOutput->isCacheable() ) {
1811                         $this->enableClientCache( false );
1812                 }
1813                 $this->mNoGallery = $parserOutput->getNoGallery();
1814                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1815                 $this->addModules( $parserOutput->getModules() );
1816                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1817                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1818                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1819                 $this->mPreventClickjacking = $this->mPreventClickjacking
1820                         || $parserOutput->preventClickjacking();
1821
1822                 // Template versioning...
1823                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1824                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1825                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1826                         } else {
1827                                 $this->mTemplateIds[$ns] = $dbks;
1828                         }
1829                 }
1830                 // File versioning...
1831                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1832                         $this->mImageTimeKeys[$dbk] = $data;
1833                 }
1834
1835                 // Hooks registered in the object
1836                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1837                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1838                         list( $hookName, $data ) = $hookInfo;
1839                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1840                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1841                         }
1842                 }
1843
1844                 // Enable OOUI if requested via ParserOutput
1845                 if ( $parserOutput->getEnableOOUI() ) {
1846                         $this->enableOOUI();
1847                 }
1848
1849                 // Include parser limit report
1850                 if ( !$this->limitReportJSData ) {
1851                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1852                 }
1853
1854                 // Link flags are ignored for now, but may in the future be
1855                 // used to mark individual language links.
1856                 $linkFlags = [];
1857                 // Avoid PHP 7.1 warning of passing $this by reference
1858                 $outputPage = $this;
1859                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1860                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1861
1862                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
1863                 // so that extensions may modify ParserOutput to toggle TOC.
1864                 // This cannot be moved to addParserOutputText because that is not
1865                 // called by EditPage for Preview.
1866                 if ( $parserOutput->getTOCHTML() ) {
1867                         $this->mEnableTOC = true;
1868                 }
1869         }
1870
1871         /**
1872          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1873          * ParserOutput object, without any other metadata.
1874          *
1875          * @since 1.24
1876          * @param ParserOutput $parserOutput
1877          * @param array $poOptions Options to ParserOutput::getText()
1878          */
1879         public function addParserOutputContent( $parserOutput, $poOptions = [] ) {
1880                 $this->addParserOutputText( $parserOutput, $poOptions );
1881
1882                 $this->addModules( $parserOutput->getModules() );
1883                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1884                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1885
1886                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1887         }
1888
1889         /**
1890          * Add the HTML associated with a ParserOutput object, without any metadata.
1891          *
1892          * @since 1.24
1893          * @param ParserOutput $parserOutput
1894          * @param array $poOptions Options to ParserOutput::getText()
1895          */
1896         public function addParserOutputText( $parserOutput, $poOptions = [] ) {
1897                 $text = $parserOutput->getText( $poOptions );
1898                 // Avoid PHP 7.1 warning of passing $this by reference
1899                 $outputPage = $this;
1900                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1901                 $this->addHTML( $text );
1902         }
1903
1904         /**
1905          * Add everything from a ParserOutput object.
1906          *
1907          * @param ParserOutput $parserOutput
1908          * @param array $poOptions Options to ParserOutput::getText()
1909          */
1910         function addParserOutput( $parserOutput, $poOptions = [] ) {
1911                 $this->addParserOutputMetadata( $parserOutput );
1912                 $this->addParserOutputText( $parserOutput, $poOptions );
1913         }
1914
1915         /**
1916          * Add the output of a QuickTemplate to the output buffer
1917          *
1918          * @param QuickTemplate &$template
1919          */
1920         public function addTemplate( &$template ) {
1921                 $this->addHTML( $template->getHTML() );
1922         }
1923
1924         /**
1925          * Parse wikitext and return the HTML.
1926          *
1927          * @param string $text
1928          * @param bool $linestart Is this the start of a line?
1929          * @param bool $interface Use interface language ($wgLang instead of
1930          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1931          *   This also disables LanguageConverter.
1932          * @param Language|null $language Target language object, will override $interface
1933          * @throws MWException
1934          * @return string HTML
1935          */
1936         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1937                 global $wgParser;
1938
1939                 if ( is_null( $this->getTitle() ) ) {
1940                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1941                 }
1942
1943                 $popts = $this->parserOptions();
1944                 if ( $interface ) {
1945                         $popts->setInterfaceMessage( true );
1946                 }
1947                 if ( $language !== null ) {
1948                         $oldLang = $popts->setTargetLanguage( $language );
1949                 }
1950
1951                 $parserOutput = $wgParser->getFreshParser()->parse(
1952                         $text, $this->getTitle(), $popts,
1953                         $linestart, true, $this->mRevisionId
1954                 );
1955
1956                 if ( $interface ) {
1957                         $popts->setInterfaceMessage( false );
1958                 }
1959                 if ( $language !== null ) {
1960                         $popts->setTargetLanguage( $oldLang );
1961                 }
1962
1963                 return $parserOutput->getText( [
1964                         'enableSectionEditLinks' => false,
1965                 ] );
1966         }
1967
1968         /**
1969          * Parse wikitext, strip paragraphs, and return the HTML.
1970          *
1971          * @param string $text
1972          * @param bool $linestart Is this the start of a line?
1973          * @param bool $interface Use interface language ($wgLang instead of
1974          *   $wgContLang) while parsing language sensitive magic
1975          *   words like GRAMMAR and PLURAL
1976          * @return string HTML
1977          */
1978         public function parseInline( $text, $linestart = true, $interface = false ) {
1979                 $parsed = $this->parse( $text, $linestart, $interface );
1980                 return Parser::stripOuterParagraph( $parsed );
1981         }
1982
1983         /**
1984          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1985          *
1986          * @param int $maxage Maximum cache time on the CDN, in seconds.
1987          */
1988         public function setCdnMaxage( $maxage ) {
1989                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1990         }
1991
1992         /**
1993          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1994          *
1995          * @param int $maxage Maximum cache time on the CDN, in seconds
1996          * @since 1.27
1997          */
1998         public function lowerCdnMaxage( $maxage ) {
1999                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
2000                 $this->setCdnMaxage( $this->mCdnMaxage );
2001         }
2002
2003         /**
2004          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
2005          *
2006          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
2007          * the TTL is higher the older the $mtime timestamp is. Essentially, the
2008          * TTL is 90% of the age of the object, subject to the min and max.
2009          *
2010          * @param string|int|float|bool|null $mtime Last-Modified timestamp
2011          * @param int $minTTL Mimimum TTL in seconds [default: 1 minute]
2012          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
2013          * @return int TTL in seconds
2014          * @since 1.28
2015          */
2016         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
2017                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
2018                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
2019
2020                 if ( $mtime === null || $mtime === false ) {
2021                         return $minTTL; // entity does not exist
2022                 }
2023
2024                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
2025                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
2026                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
2027
2028                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2029
2030                 return $adaptiveTTL;
2031         }
2032
2033         /**
2034          * Use enableClientCache(false) to force it to send nocache headers
2035          *
2036          * @param bool $state
2037          *
2038          * @return bool
2039          */
2040         public function enableClientCache( $state ) {
2041                 return wfSetVar( $this->mEnableClientCache, $state );
2042         }
2043
2044         /**
2045          * Get the list of cookies that will influence on the cache
2046          *
2047          * @return array
2048          */
2049         function getCacheVaryCookies() {
2050                 static $cookies;
2051                 if ( $cookies === null ) {
2052                         $config = $this->getConfig();
2053                         $cookies = array_merge(
2054                                 SessionManager::singleton()->getVaryCookies(),
2055                                 [
2056                                         'forceHTTPS',
2057                                 ],
2058                                 $config->get( 'CacheVaryCookies' )
2059                         );
2060                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2061                 }
2062                 return $cookies;
2063         }
2064
2065         /**
2066          * Check if the request has a cache-varying cookie header
2067          * If it does, it's very important that we don't allow public caching
2068          *
2069          * @return bool
2070          */
2071         function haveCacheVaryCookies() {
2072                 $request = $this->getRequest();
2073                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2074                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2075                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2076                                 return true;
2077                         }
2078                 }
2079                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2080                 return false;
2081         }
2082
2083         /**
2084          * Add an HTTP header that will influence on the cache
2085          *
2086          * @param string $header Header name
2087          * @param string[]|null $option Options for the Key header. See
2088          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2089          * for the list of valid options.
2090          */
2091         public function addVaryHeader( $header, array $option = null ) {
2092                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2093                         $this->mVaryHeader[$header] = [];
2094                 }
2095                 if ( !is_array( $option ) ) {
2096                         $option = [];
2097                 }
2098                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2099         }
2100
2101         /**
2102          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2103          * such as Accept-Encoding or Cookie
2104          *
2105          * @return string
2106          */
2107         public function getVaryHeader() {
2108                 // If we vary on cookies, let's make sure it's always included here too.
2109                 if ( $this->getCacheVaryCookies() ) {
2110                         $this->addVaryHeader( 'Cookie' );
2111                 }
2112
2113                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2114                         $this->addVaryHeader( $header, $options );
2115                 }
2116                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2117         }
2118
2119         /**
2120          * Add an HTTP Link: header
2121          *
2122          * @param string $header Header value
2123          */
2124         public function addLinkHeader( $header ) {
2125                 $this->mLinkHeader[] = $header;
2126         }
2127
2128         /**
2129          * Return a Link: header. Based on the values of $mLinkHeader.
2130          *
2131          * @return string
2132          */
2133         public function getLinkHeader() {
2134                 if ( !$this->mLinkHeader ) {
2135                         return false;
2136                 }
2137
2138                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2139         }
2140
2141         /**
2142          * Get a complete Key header
2143          *
2144          * @return string
2145          */
2146         public function getKeyHeader() {
2147                 $cvCookies = $this->getCacheVaryCookies();
2148
2149                 $cookiesOption = [];
2150                 foreach ( $cvCookies as $cookieName ) {
2151                         $cookiesOption[] = 'param=' . $cookieName;
2152                 }
2153                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2154
2155                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2156                         $this->addVaryHeader( $header, $options );
2157                 }
2158
2159                 $headers = [];
2160                 foreach ( $this->mVaryHeader as $header => $option ) {
2161                         $newheader = $header;
2162                         if ( is_array( $option ) && count( $option ) > 0 ) {
2163                                 $newheader .= ';' . implode( ';', $option );
2164                         }
2165                         $headers[] = $newheader;
2166                 }
2167                 $key = 'Key: ' . implode( ',', $headers );
2168
2169                 return $key;
2170         }
2171
2172         /**
2173          * T23672: Add Accept-Language to Vary and Key headers
2174          * if there's no 'variant' parameter existed in GET.
2175          *
2176          * For example:
2177          *   /w/index.php?title=Main_page should always be served; but
2178          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2179          */
2180         function addAcceptLanguage() {
2181                 $title = $this->getTitle();
2182                 if ( !$title instanceof Title ) {
2183                         return;
2184                 }
2185
2186                 $lang = $title->getPageLanguage();
2187                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2188                         $variants = $lang->getVariants();
2189                         $aloption = [];
2190                         foreach ( $variants as $variant ) {
2191                                 if ( $variant === $lang->getCode() ) {
2192                                         continue;
2193                                 } else {
2194                                         $aloption[] = 'substr=' . $variant;
2195
2196                                         // IE and some other browsers use BCP 47 standards in
2197                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2198                                         // We should handle these too.
2199                                         $variantBCP47 = LanguageCode::bcp47( $variant );
2200                                         if ( $variantBCP47 !== $variant ) {
2201                                                 $aloption[] = 'substr=' . $variantBCP47;
2202                                         }
2203                                 }
2204                         }
2205                         $this->addVaryHeader( 'Accept-Language', $aloption );
2206                 }
2207         }
2208
2209         /**
2210          * Set a flag which will cause an X-Frame-Options header appropriate for
2211          * edit pages to be sent. The header value is controlled by
2212          * $wgEditPageFrameOptions.
2213          *
2214          * This is the default for special pages. If you display a CSRF-protected
2215          * form on an ordinary view page, then you need to call this function.
2216          *
2217          * @param bool $enable
2218          */
2219         public function preventClickjacking( $enable = true ) {
2220                 $this->mPreventClickjacking = $enable;
2221         }
2222
2223         /**
2224          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2225          * This can be called from pages which do not contain any CSRF-protected
2226          * HTML form.
2227          */
2228         public function allowClickjacking() {
2229                 $this->mPreventClickjacking = false;
2230         }
2231
2232         /**
2233          * Get the prevent-clickjacking flag
2234          *
2235          * @since 1.24
2236          * @return bool
2237          */
2238         public function getPreventClickjacking() {
2239                 return $this->mPreventClickjacking;
2240         }
2241
2242         /**
2243          * Get the X-Frame-Options header value (without the name part), or false
2244          * if there isn't one. This is used by Skin to determine whether to enable
2245          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2246          *
2247          * @return string|false
2248          */
2249         public function getFrameOptions() {
2250                 $config = $this->getConfig();
2251                 if ( $config->get( 'BreakFrames' ) ) {
2252                         return 'DENY';
2253                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2254                         return $config->get( 'EditPageFrameOptions' );
2255                 }
2256                 return false;
2257         }
2258
2259         /**
2260          * Send cache control HTTP headers
2261          */
2262         public function sendCacheControl() {
2263                 $response = $this->getRequest()->response();
2264                 $config = $this->getConfig();
2265
2266                 $this->addVaryHeader( 'Cookie' );
2267                 $this->addAcceptLanguage();
2268
2269                 # don't serve compressed data to clients who can't handle it
2270                 # maintain different caches for logged-in users and non-logged in ones
2271                 $response->header( $this->getVaryHeader() );
2272
2273                 if ( $config->get( 'UseKeyHeader' ) ) {
2274                         $response->header( $this->getKeyHeader() );
2275                 }
2276
2277                 if ( $this->mEnableClientCache ) {
2278                         if (
2279                                 $config->get( 'UseSquid' ) &&
2280                                 !$response->hasCookies() &&
2281                                 !SessionManager::getGlobalSession()->isPersistent() &&
2282                                 !$this->isPrintable() &&
2283                                 $this->mCdnMaxage != 0 &&
2284                                 !$this->haveCacheVaryCookies()
2285                         ) {
2286                                 if ( $config->get( 'UseESI' ) ) {
2287                                         # We'll purge the proxy cache explicitly, but require end user agents
2288                                         # to revalidate against the proxy on each visit.
2289                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2290                                         wfDebug( __METHOD__ .
2291                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2292                                         # start with a shorter timeout for initial testing
2293                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2294                                         $response->header(
2295                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2296                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2297                                         );
2298                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2299                                 } else {
2300                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2301                                         # to revalidate against the proxy on each visit.
2302                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2303                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2304                                         wfDebug( __METHOD__ .
2305                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2306                                         # start with a shorter timeout for initial testing
2307                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2308                                         $response->header( "Cache-Control: " .
2309                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2310                                 }
2311                         } else {
2312                                 # We do want clients to cache if they can, but they *must* check for updates
2313                                 # on revisiting the page.
2314                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2315                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2316                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2317                         }
2318                         if ( $this->mLastModified ) {
2319                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2320                         }
2321                 } else {
2322                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2323
2324                         # In general, the absence of a last modified header should be enough to prevent
2325                         # the client from using its cache. We send a few other things just to make sure.
2326                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2327                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2328                         $response->header( 'Pragma: no-cache' );
2329                 }
2330         }
2331
2332         /**
2333          * Transfer styles and JavaScript modules from skin.
2334          *
2335          * @param Skin $sk to load modules for
2336          */
2337         public function loadSkinModules( $sk ) {
2338                 foreach ( $sk->getDefaultModules() as $group => $modules ) {
2339                         if ( $group === 'styles' ) {
2340                                 foreach ( $modules as $key => $moduleMembers ) {
2341                                         $this->addModuleStyles( $moduleMembers );
2342                                 }
2343                         } else {
2344                                 $this->addModules( $modules );
2345                         }
2346                 }
2347         }
2348
2349         /**
2350          * Finally, all the text has been munged and accumulated into
2351          * the object, let's actually output it:
2352          *
2353          * @param bool $return Set to true to get the result as a string rather than sending it
2354          * @return string|null
2355          * @throws Exception
2356          * @throws FatalError
2357          * @throws MWException
2358          */
2359         public function output( $return = false ) {
2360                 global $wgContLang;
2361
2362                 if ( $this->mDoNothing ) {
2363                         return $return ? '' : null;
2364                 }
2365
2366                 $response = $this->getRequest()->response();
2367                 $config = $this->getConfig();
2368
2369                 if ( $this->mRedirect != '' ) {
2370                         # Standards require redirect URLs to be absolute
2371                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2372
2373                         $redirect = $this->mRedirect;
2374                         $code = $this->mRedirectCode;
2375
2376                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2377                                 if ( $code == '301' || $code == '303' ) {
2378                                         if ( !$config->get( 'DebugRedirects' ) ) {
2379                                                 $response->statusHeader( $code );
2380                                         }
2381                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2382                                 }
2383                                 if ( $config->get( 'VaryOnXFP' ) ) {
2384                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2385                                 }
2386                                 $this->sendCacheControl();
2387
2388                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2389                                 if ( $config->get( 'DebugRedirects' ) ) {
2390                                         $url = htmlspecialchars( $redirect );
2391                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2392                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2393                                         print "</body>\n</html>\n";
2394                                 } else {
2395                                         $response->header( 'Location: ' . $redirect );
2396                                 }
2397                         }
2398
2399                         return $return ? '' : null;
2400                 } elseif ( $this->mStatusCode ) {
2401                         $response->statusHeader( $this->mStatusCode );
2402                 }
2403
2404                 # Buffer output; final headers may depend on later processing
2405                 ob_start();
2406
2407                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2408                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2409
2410                 if ( !$this->mArticleBodyOnly ) {
2411                         $sk = $this->getSkin();
2412
2413                         if ( $sk->shouldPreloadLogo() ) {
2414                                 $this->addLogoPreloadLinkHeaders();
2415                         }
2416                 }
2417
2418                 $linkHeader = $this->getLinkHeader();
2419                 if ( $linkHeader ) {
2420                         $response->header( $linkHeader );
2421                 }
2422
2423                 // Prevent framing, if requested
2424                 $frameOptions = $this->getFrameOptions();
2425                 if ( $frameOptions ) {
2426                         $response->header( "X-Frame-Options: $frameOptions" );
2427                 }
2428
2429                 ContentSecurityPolicy::sendHeaders( $this );
2430
2431                 if ( $this->mArticleBodyOnly ) {
2432                         echo $this->mBodytext;
2433                 } else {
2434                         // Enable safe mode if requested (T152169)
2435                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2436                                 $this->disallowUserJs();
2437                         }
2438
2439                         $sk = $this->getSkin();
2440                         $this->loadSkinModules( $sk );
2441
2442                         MWDebug::addModules( $this );
2443
2444                         // Avoid PHP 7.1 warning of passing $this by reference
2445                         $outputPage = $this;
2446                         // Hook that allows last minute changes to the output page, e.g.
2447                         // adding of CSS or Javascript by extensions.
2448                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2449
2450                         try {
2451                                 $sk->outputPage();
2452                         } catch ( Exception $e ) {
2453                                 ob_end_clean(); // bug T129657
2454                                 throw $e;
2455                         }
2456                 }
2457
2458                 try {
2459                         // This hook allows last minute changes to final overall output by modifying output buffer
2460                         Hooks::runWithoutAbort( 'AfterFinalPageOutput', [ $this ] );
2461                 } catch ( Exception $e ) {
2462                         ob_end_clean(); // bug T129657
2463                         throw $e;
2464                 }
2465
2466                 $this->sendCacheControl();
2467
2468                 if ( $return ) {
2469                         return ob_get_clean();
2470                 } else {
2471                         ob_end_flush();
2472                         return null;
2473                 }
2474         }
2475
2476         /**
2477          * Prepare this object to display an error page; disable caching and
2478          * indexing, clear the current text and redirect, set the page's title
2479          * and optionally an custom HTML title (content of the "<title>" tag).
2480          *
2481          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2482          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2483          *                   optional, if not passed the "<title>" attribute will be
2484          *                   based on $pageTitle
2485          */
2486         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2487                 $this->setPageTitle( $pageTitle );
2488                 if ( $htmlTitle !== false ) {
2489                         $this->setHTMLTitle( $htmlTitle );
2490                 }
2491                 $this->setRobotPolicy( 'noindex,nofollow' );
2492                 $this->setArticleRelated( false );
2493                 $this->enableClientCache( false );
2494                 $this->mRedirect = '';
2495                 $this->clearSubtitle();
2496                 $this->clearHTML();
2497         }
2498
2499         /**
2500          * Output a standard error page
2501          *
2502          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2503          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2504          * showErrorPage( 'titlemsg', $messageObject );
2505          * showErrorPage( $titleMessageObject, $messageObject );
2506          *
2507          * @param string|Message $title Message key (string) for page title, or a Message object
2508          * @param string|Message $msg Message key (string) for page text, or a Message object
2509          * @param array $params Message parameters; ignored if $msg is a Message object
2510          */
2511         public function showErrorPage( $title, $msg, $params = [] ) {
2512                 if ( !$title instanceof Message ) {
2513                         $title = $this->msg( $title );
2514                 }
2515
2516                 $this->prepareErrorPage( $title );
2517
2518                 if ( $msg instanceof Message ) {
2519                         if ( $params !== [] ) {
2520                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2521                                         . 'is discarded when the $msg argument is a Message object instead of '
2522                                         . 'a string.', E_USER_NOTICE );
2523                         }
2524                         $this->addHTML( $msg->parseAsBlock() );
2525                 } else {
2526                         $this->addWikiMsgArray( $msg, $params );
2527                 }
2528
2529                 $this->returnToMain();
2530         }
2531
2532         /**
2533          * Output a standard permission error page
2534          *
2535          * @param array $errors Error message keys or [key, param...] arrays
2536          * @param string|null $action Action that was denied or null if unknown
2537          */
2538         public function showPermissionsErrorPage( array $errors, $action = null ) {
2539                 foreach ( $errors as $key => $error ) {
2540                         $errors[$key] = (array)$error;
2541                 }
2542
2543                 // For some action (read, edit, create and upload), display a "login to do this action"
2544                 // error if all of the following conditions are met:
2545                 // 1. the user is not logged in
2546                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2547                 // 3. the error can be avoided simply by logging in
2548                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2549                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2550                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2551                         && ( User::groupHasPermission( 'user', $action )
2552                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2553                 ) {
2554                         $displayReturnto = null;
2555
2556                         # Due to T34276, if a user does not have read permissions,
2557                         # $this->getTitle() will just give Special:Badtitle, which is
2558                         # not especially useful as a returnto parameter. Use the title
2559                         # from the request instead, if there was one.
2560                         $request = $this->getRequest();
2561                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2562                         if ( $action == 'edit' ) {
2563                                 $msg = 'whitelistedittext';
2564                                 $displayReturnto = $returnto;
2565                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2566                                 $msg = 'nocreatetext';
2567                         } elseif ( $action == 'upload' ) {
2568                                 $msg = 'uploadnologintext';
2569                         } else { # Read
2570                                 $msg = 'loginreqpagetext';
2571                                 $displayReturnto = Title::newMainPage();
2572                         }
2573
2574                         $query = [];
2575
2576                         if ( $returnto ) {
2577                                 $query['returnto'] = $returnto->getPrefixedText();
2578
2579                                 if ( !$request->wasPosted() ) {
2580                                         $returntoquery = $request->getValues();
2581                                         unset( $returntoquery['title'] );
2582                                         unset( $returntoquery['returnto'] );
2583                                         unset( $returntoquery['returntoquery'] );
2584                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2585                                 }
2586                         }
2587                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2588                         $loginLink = $linkRenderer->makeKnownLink(
2589                                 SpecialPage::getTitleFor( 'Userlogin' ),
2590                                 $this->msg( 'loginreqlink' )->text(),
2591                                 [],
2592                                 $query
2593                         );
2594
2595                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2596                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2597
2598                         # Don't return to a page the user can't read otherwise
2599                         # we'll end up in a pointless loop
2600                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2601                                 $this->returnToMain( null, $displayReturnto );
2602                         }
2603                 } else {
2604                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2605                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2606                 }
2607         }
2608
2609         /**
2610          * Display an error page indicating that a given version of MediaWiki is
2611          * required to use it
2612          *
2613          * @param mixed $version The version of MediaWiki needed to use the page
2614          */
2615         public function versionRequired( $version ) {
2616                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2617
2618                 $this->addWikiMsg( 'versionrequiredtext', $version );
2619                 $this->returnToMain();
2620         }
2621
2622         /**
2623          * Format a list of error messages
2624          *
2625          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2626          * @param string|null $action Action that was denied or null if unknown
2627          * @return string The wikitext error-messages, formatted into a list.
2628          */
2629         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2630                 if ( $action == null ) {
2631                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2632                 } else {
2633                         $action_desc = $this->msg( "action-$action" )->plain();
2634                         $text = $this->msg(
2635                                 'permissionserrorstext-withaction',
2636                                 count( $errors ),
2637                                 $action_desc
2638                         )->plain() . "\n\n";
2639                 }
2640
2641                 if ( count( $errors ) > 1 ) {
2642                         $text .= '<ul class="permissions-errors">' . "\n";
2643
2644                         foreach ( $errors as $error ) {
2645                                 $text .= '<li>';
2646                                 $text .= $this->msg( ...$error )->plain();
2647                                 $text .= "</li>\n";
2648                         }
2649                         $text .= '</ul>';
2650                 } else {
2651                         $text .= "<div class=\"permissions-errors\">\n" .
2652                                         $this->msg( ...reset( $errors ) )->plain() .
2653                                         "\n</div>";
2654                 }
2655
2656                 return $text;
2657         }
2658
2659         /**
2660          * Show a warning about replica DB lag
2661          *
2662          * If the lag is higher than $wgSlaveLagCritical seconds,
2663          * then the warning is a bit more obvious. If the lag is
2664          * lower than $wgSlaveLagWarning, then no warning is shown.
2665          *
2666          * @param int $lag Slave lag
2667          */
2668         public function showLagWarning( $lag ) {
2669                 $config = $this->getConfig();
2670                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2671                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2672                         $message = $lag < $config->get( 'SlaveLagCritical' )
2673                                 ? 'lag-warn-normal'
2674                                 : 'lag-warn-high';
2675                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2676                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2677                 }
2678         }
2679
2680         /**
2681          * Output an error page
2682          *
2683          * @note FatalError exception class provides an alternative.
2684          * @param string $message Error to output. Must be escaped for HTML.
2685          */
2686         public function showFatalError( $message ) {
2687                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2688
2689                 $this->addHTML( $message );
2690         }
2691
2692         /**
2693          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2694          */
2695         public function showUnexpectedValueError( $name, $val ) {
2696                 wfDeprecated( __METHOD__, '1.32' );
2697                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->escaped() );
2698         }
2699
2700         /**
2701          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2702          */
2703         public function showFileCopyError( $old, $new ) {
2704                 wfDeprecated( __METHOD__, '1.32' );
2705                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->escaped() );
2706         }
2707
2708         /**
2709          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2710          */
2711         public function showFileRenameError( $old, $new ) {
2712                 wfDeprecated( __METHOD__, '1.32' );
2713                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->escpaed() );
2714         }
2715
2716         /**
2717          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2718          */
2719         public function showFileDeleteError( $name ) {
2720                 wfDeprecated( __METHOD__, '1.32' );
2721                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->escaped() );
2722         }
2723
2724         /**
2725          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2726          */
2727         public function showFileNotFoundError( $name ) {
2728                 wfDeprecated( __METHOD__, '1.32' );
2729                 $this->showFatalError( $this->msg( 'filenotfound', $name )->escaped() );
2730         }
2731
2732         /**
2733          * Add a "return to" link pointing to a specified title
2734          *
2735          * @param Title $title Title to link
2736          * @param array $query Query string parameters
2737          * @param string|null $text Text of the link (input is not escaped)
2738          * @param array $options Options array to pass to Linker
2739          */
2740         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2741                 $linkRenderer = MediaWikiServices::getInstance()
2742                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
2743                 $link = $this->msg( 'returnto' )->rawParams(
2744                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
2745                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2746         }
2747
2748         /**
2749          * Add a "return to" link pointing to a specified title,
2750          * or the title indicated in the request, or else the main page
2751          *
2752          * @param mixed|null $unused
2753          * @param Title|string|null $returnto Title or String to return to
2754          * @param string|null $returntoquery Query string for the return to link
2755          */
2756         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2757                 if ( $returnto == null ) {
2758                         $returnto = $this->getRequest()->getText( 'returnto' );
2759                 }
2760
2761                 if ( $returntoquery == null ) {
2762                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2763                 }
2764
2765                 if ( $returnto === '' ) {
2766                         $returnto = Title::newMainPage();
2767                 }
2768
2769                 if ( is_object( $returnto ) ) {
2770                         $titleObj = $returnto;
2771                 } else {
2772                         $titleObj = Title::newFromText( $returnto );
2773                 }
2774                 // We don't want people to return to external interwiki. That
2775                 // might potentially be used as part of a phishing scheme
2776                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
2777                         $titleObj = Title::newMainPage();
2778                 }
2779
2780                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2781         }
2782
2783         private function getRlClientContext() {
2784                 if ( !$this->rlClientContext ) {
2785                         $query = ResourceLoader::makeLoaderQuery(
2786                                 [], // modules; not relevant
2787                                 $this->getLanguage()->getCode(),
2788                                 $this->getSkin()->getSkinName(),
2789                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2790                                 null, // version; not relevant
2791                                 ResourceLoader::inDebugMode(),
2792                                 null, // only; not relevant
2793                                 $this->isPrintable(),
2794                                 $this->getRequest()->getBool( 'handheld' )
2795                         );
2796                         $this->rlClientContext = new ResourceLoaderContext(
2797                                 $this->getResourceLoader(),
2798                                 new FauxRequest( $query )
2799                         );
2800                         if ( $this->contentOverrideCallbacks ) {
2801                                 $this->rlClientContext = new DerivativeResourceLoaderContext( $this->rlClientContext );
2802                                 $this->rlClientContext->setContentOverrideCallback( function ( Title $title ) {
2803                                         foreach ( $this->contentOverrideCallbacks as $callback ) {
2804                                                 $content = call_user_func( $callback, $title );
2805                                                 if ( $content !== null ) {
2806                                                         return $content;
2807                                                 }
2808                                         }
2809                                         return null;
2810                                 } );
2811                         }
2812                 }
2813                 return $this->rlClientContext;
2814         }
2815
2816         /**
2817          * Call this to freeze the module queue and JS config and create a formatter.
2818          *
2819          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2820          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2821          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2822          * the module filters retroactively. Skins and extension hooks may also add modules until very
2823          * late in the request lifecycle.
2824          *
2825          * @return ResourceLoaderClientHtml
2826          */
2827         public function getRlClient() {
2828                 if ( !$this->rlClient ) {
2829                         $context = $this->getRlClientContext();
2830                         $rl = $this->getResourceLoader();
2831                         $this->addModules( [
2832                                 'user',
2833                                 'user.options',
2834                                 'user.tokens',
2835                         ] );
2836                         $this->addModuleStyles( [
2837                                 'site.styles',
2838                                 'noscript',
2839                                 'user.styles',
2840                         ] );
2841                         $this->getSkin()->setupSkinUserCss( $this );
2842
2843                         // Prepare exempt modules for buildExemptModules()
2844                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2845                         $exemptStates = [];
2846                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2847
2848                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2849                         // Separate user-specific batch for improved cache-hit ratio.
2850                         $userBatch = [ 'user.styles', 'user' ];
2851                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2852                         $dbr = wfGetDB( DB_REPLICA );
2853                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2854                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2855
2856                         // Filter out modules handled by buildExemptModules()
2857                         $moduleStyles = array_filter( $moduleStyles,
2858                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2859                                         $module = $rl->getModule( $name );
2860                                         if ( $module ) {
2861                                                 $group = $module->getGroup();
2862                                                 if ( isset( $exemptGroups[$group] ) ) {
2863                                                         $exemptStates[$name] = 'ready';
2864                                                         if ( !$module->isKnownEmpty( $context ) ) {
2865                                                                 // E.g. Don't output empty <styles>
2866                                                                 $exemptGroups[$group][] = $name;
2867                                                         }
2868                                                         return false;
2869                                                 }
2870                                         }
2871                                         return true;
2872                                 }
2873                         );
2874                         $this->rlExemptStyleModules = $exemptGroups;
2875
2876                         $rlClient = new ResourceLoaderClientHtml( $context, [
2877                                 'target' => $this->getTarget(),
2878                                 'nonce' => $this->getCSPNonce(),
2879                                 // When 'safemode', disallowUserJs(), or reduceAllowedModules() is used
2880                                 // to only restrict modules to ORIGIN_CORE (ie. disallow ORIGIN_USER), the list of
2881                                 // modules enqueud for loading on this page is filtered to just those.
2882                                 // However, to make sure we also apply the restriction to dynamic dependencies and
2883                                 // lazy-loaded modules at run-time on the client-side, pass 'safemode' down to the
2884                                 // StartupModule so that the client-side registry will not contain any restricted
2885                                 // modules either. (T152169, T185303)
2886                                 'safemode' => ( $this->getAllowedModules( ResourceLoaderModule::TYPE_COMBINED )
2887                                         <= ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
2888                                 ) ? '1' : null,
2889                         ] );
2890                         $rlClient->setConfig( $this->getJSVars() );
2891                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2892                         $rlClient->setModuleStyles( $moduleStyles );
2893                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2894                         $rlClient->setExemptStates( $exemptStates );
2895                         $this->rlClient = $rlClient;
2896                 }
2897                 return $this->rlClient;
2898         }
2899
2900         /**
2901          * @param Skin $sk The given Skin
2902          * @param bool $includeStyle Unused
2903          * @return string The doctype, opening "<html>", and head element.
2904          */
2905         public function headElement( Skin $sk, $includeStyle = true ) {
2906                 global $wgContLang;
2907
2908                 $userdir = $this->getLanguage()->getDir();
2909                 $sitedir = $wgContLang->getDir();
2910
2911                 $pieces = [];
2912                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2913                         $this->getRlClient()->getDocumentAttributes(),
2914                         $sk->getHtmlElementAttributes()
2915                 ) );
2916                 $pieces[] = Html::openElement( 'head' );
2917
2918                 if ( $this->getHTMLTitle() == '' ) {
2919                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2920                 }
2921
2922                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2923                         // Add <meta charset="UTF-8">
2924                         // This should be before <title> since it defines the charset used by
2925                         // text including the text inside <title>.
2926                         // The spec recommends defining XHTML5's charset using the XML declaration
2927                         // instead of meta.
2928                         // Our XML declaration is output by Html::htmlHeader.
2929                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2930                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2931                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2932                 }
2933
2934                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2935                 $pieces[] = $this->getRlClient()->getHeadHtml();
2936                 $pieces[] = $this->buildExemptModules();
2937                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2938                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2939
2940                 // Use an IE conditional comment to serve the script only to old IE
2941                 $pieces[] = '<!--[if lt IE 9]>' .
2942                         ResourceLoaderClientHtml::makeLoad(
2943                                 ResourceLoaderContext::newDummyContext(),
2944                                 [ 'html5shiv' ],
2945                                 ResourceLoaderModule::TYPE_SCRIPTS,
2946                                 [ 'sync' => true ],
2947                                 $this->getCSPNonce()
2948                         ) .
2949                         '<![endif]-->';
2950
2951                 $pieces[] = Html::closeElement( 'head' );
2952
2953                 $bodyClasses = $this->mAdditionalBodyClasses;
2954                 $bodyClasses[] = 'mediawiki';
2955
2956                 # Classes for LTR/RTL directionality support
2957                 $bodyClasses[] = $userdir;
2958                 $bodyClasses[] = "sitedir-$sitedir";
2959
2960                 $underline = $this->getUser()->getOption( 'underline' );
2961                 if ( $underline < 2 ) {
2962                         // The following classes can be used here:
2963                         // * mw-underline-always
2964                         // * mw-underline-never
2965                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2966                 }
2967
2968                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2969                         # A <body> class is probably not the best way to do this . . .
2970                         $bodyClasses[] = 'capitalize-all-nouns';
2971                 }
2972
2973                 // Parser feature migration class
2974                 // The idea is that this will eventually be removed, after the wikitext
2975                 // which requires it is cleaned up.
2976                 $bodyClasses[] = 'mw-hide-empty-elt';
2977
2978                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2979                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2980                 $bodyClasses[] =
2981                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2982
2983                 $bodyAttrs = [];
2984                 // While the implode() is not strictly needed, it's used for backwards compatibility
2985                 // (this used to be built as a string and hooks likely still expect that).
2986                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2987
2988                 // Allow skins and extensions to add body attributes they need
2989                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2990                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2991
2992                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2993
2994                 return self::combineWrappedStrings( $pieces );
2995         }
2996
2997         /**
2998          * Get a ResourceLoader object associated with this OutputPage
2999          *
3000          * @return ResourceLoader
3001          */
3002         public function getResourceLoader() {
3003                 if ( is_null( $this->mResourceLoader ) ) {
3004                         $this->mResourceLoader = new ResourceLoader(
3005                                 $this->getConfig(),
3006                                 LoggerFactory::getInstance( 'resourceloader' )
3007                         );
3008                 }
3009                 return $this->mResourceLoader;
3010         }
3011
3012         /**
3013          * Explicily load or embed modules on a page.
3014          *
3015          * @param array|string $modules One or more module names
3016          * @param string $only ResourceLoaderModule TYPE_ class constant
3017          * @param array $extraQuery [optional] Array with extra query parameters for the request
3018          * @return string|WrappedStringList HTML
3019          */
3020         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
3021                 // Apply 'target' and 'origin' filters
3022                 $modules = $this->filterModules( (array)$modules, null, $only );
3023
3024                 return ResourceLoaderClientHtml::makeLoad(
3025                         $this->getRlClientContext(),
3026                         $modules,
3027                         $only,
3028                         $extraQuery,
3029                         $this->getCSPNonce()
3030                 );
3031         }
3032
3033         /**
3034          * Combine WrappedString chunks and filter out empty ones
3035          *
3036          * @param array $chunks
3037          * @return string|WrappedStringList HTML
3038          */
3039         protected static function combineWrappedStrings( array $chunks ) {
3040                 // Filter out empty values
3041                 $chunks = array_filter( $chunks, 'strlen' );
3042                 return WrappedString::join( "\n", $chunks );
3043         }
3044
3045         /**
3046          * JS stuff to put at the bottom of the `<body>`.
3047          * These are legacy scripts ($this->mScripts), and user JS.
3048          *
3049          * @return string|WrappedStringList HTML
3050          */
3051         public function getBottomScripts() {
3052                 $chunks = [];
3053                 $chunks[] = $this->getRlClient()->getBodyHtml();
3054
3055                 // Legacy non-ResourceLoader scripts
3056                 $chunks[] = $this->mScripts;
3057
3058                 if ( $this->limitReportJSData ) {
3059                         $chunks[] = ResourceLoader::makeInlineScript(
3060                                 ResourceLoader::makeConfigSetScript(
3061                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3062                                 ),
3063                                 $this->getCSPNonce()
3064                         );
3065                 }
3066
3067                 return self::combineWrappedStrings( $chunks );
3068         }
3069
3070         /**
3071          * Get the javascript config vars to include on this page
3072          *
3073          * @return array Array of javascript config vars
3074          * @since 1.23
3075          */
3076         public function getJsConfigVars() {
3077                 return $this->mJsConfigVars;
3078         }
3079
3080         /**
3081          * Add one or more variables to be set in mw.config in JavaScript
3082          *
3083          * @param string|array $keys Key or array of key/value pairs
3084          * @param mixed|null $value [optional] Value of the configuration variable
3085          */
3086         public function addJsConfigVars( $keys, $value = null ) {
3087                 if ( is_array( $keys ) ) {
3088                         foreach ( $keys as $key => $value ) {
3089                                 $this->mJsConfigVars[$key] = $value;
3090                         }
3091                         return;
3092                 }
3093
3094                 $this->mJsConfigVars[$keys] = $value;
3095         }
3096
3097         /**
3098          * Get an array containing the variables to be set in mw.config in JavaScript.
3099          *
3100          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3101          * - in other words, page-independent/site-wide variables (without state).
3102          * You will only be adding bloat to the html page and causing page caches to
3103          * have to be purged on configuration changes.
3104          * @return array
3105          */
3106         public function getJSVars() {
3107                 global $wgContLang;
3108
3109                 $curRevisionId = 0;
3110                 $articleId = 0;
3111                 $canonicalSpecialPageName = false; # T23115
3112
3113                 $title = $this->getTitle();
3114                 $ns = $title->getNamespace();
3115                 $canonicalNamespace = MWNamespace::exists( $ns )
3116                         ? MWNamespace::getCanonicalName( $ns )
3117                         : $title->getNsText();
3118
3119                 $sk = $this->getSkin();
3120                 // Get the relevant title so that AJAX features can use the correct page name
3121                 // when making API requests from certain special pages (T36972).
3122                 $relevantTitle = $sk->getRelevantTitle();
3123                 $relevantUser = $sk->getRelevantUser();
3124
3125                 if ( $ns == NS_SPECIAL ) {
3126                         list( $canonicalSpecialPageName, /*...*/ ) =
3127                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3128                 } elseif ( $this->canUseWikiPage() ) {
3129                         $wikiPage = $this->getWikiPage();
3130                         $curRevisionId = $wikiPage->getLatest();
3131                         $articleId = $wikiPage->getId();
3132                 }
3133
3134                 $lang = $title->getPageViewLanguage();
3135
3136                 // Pre-process information
3137                 $separatorTransTable = $lang->separatorTransformTable();
3138                 $separatorTransTable = $separatorTransTable ?: [];
3139                 $compactSeparatorTransTable = [
3140                         implode( "\t", array_keys( $separatorTransTable ) ),
3141                         implode( "\t", $separatorTransTable ),
3142                 ];
3143                 $digitTransTable = $lang->digitTransformTable();
3144                 $digitTransTable = $digitTransTable ?: [];
3145                 $compactDigitTransTable = [
3146                         implode( "\t", array_keys( $digitTransTable ) ),
3147                         implode( "\t", $digitTransTable ),
3148                 ];
3149
3150                 $user = $this->getUser();
3151
3152                 $vars = [
3153                         'wgCanonicalNamespace' => $canonicalNamespace,
3154                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3155                         'wgNamespaceNumber' => $title->getNamespace(),
3156                         'wgPageName' => $title->getPrefixedDBkey(),
3157                         'wgTitle' => $title->getText(),
3158                         'wgCurRevisionId' => $curRevisionId,
3159                         'wgRevisionId' => (int)$this->getRevisionId(),
3160                         'wgArticleId' => $articleId,
3161                         'wgIsArticle' => $this->isArticle(),
3162                         'wgIsRedirect' => $title->isRedirect(),
3163                         'wgAction' => Action::getActionName( $this->getContext() ),
3164                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3165                         'wgUserGroups' => $user->getEffectiveGroups(),
3166                         'wgCategories' => $this->getCategories(),
3167                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3168                         'wgPageContentLanguage' => $lang->getCode(),
3169                         'wgPageContentModel' => $title->getContentModel(),
3170                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3171                         'wgDigitTransformTable' => $compactDigitTransTable,
3172                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3173                         'wgMonthNames' => $lang->getMonthNamesArray(),
3174                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3175                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3176                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3177                         'wgRequestId' => WebRequest::getRequestId(),
3178                 ];
3179
3180                 if ( $user->isLoggedIn() ) {
3181                         $vars['wgUserId'] = $user->getId();
3182                         $vars['wgUserEditCount'] = $user->getEditCount();
3183                         $userReg = $user->getRegistration();
3184                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3185                         // Get the revision ID of the oldest new message on the user's talk
3186                         // page. This can be used for constructing new message alerts on
3187                         // the client side.
3188                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3189                 }
3190
3191                 if ( $wgContLang->hasVariants() ) {
3192                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3193                 }
3194                 // Same test as SkinTemplate
3195                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3196                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3197
3198                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3199                         && $relevantTitle->quickUserCan( 'edit', $user )
3200                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3201
3202                 foreach ( $title->getRestrictionTypes() as $type ) {
3203                         // Following keys are set in $vars:
3204                         // wgRestrictionCreate, wgRestrictionEdit, wgRestrictionMove, wgRestrictionUpload
3205                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3206                 }
3207
3208                 if ( $title->isMainPage() ) {
3209                         $vars['wgIsMainPage'] = true;
3210                 }
3211
3212                 if ( $this->mRedirectedFrom ) {
3213                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3214                 }
3215
3216                 if ( $relevantUser ) {
3217                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3218                 }
3219
3220                 // Allow extensions to add their custom variables to the mw.config map.
3221                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3222                 // page-dependant but site-wide (without state).
3223                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3224                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3225
3226                 // Merge in variables from addJsConfigVars last
3227                 return array_merge( $vars, $this->getJsConfigVars() );
3228         }
3229
3230         /**
3231          * To make it harder for someone to slip a user a fake
3232          * JavaScript or CSS preview, a random token
3233          * is associated with the login session. If it's not
3234          * passed back with the preview request, we won't render
3235          * the code.
3236          *
3237          * @return bool
3238          */
3239         public function userCanPreview() {
3240                 $request = $this->getRequest();
3241                 if (
3242                         $request->getVal( 'action' ) !== 'submit' ||
3243                         !$request->wasPosted()
3244                 ) {
3245                         return false;
3246                 }
3247
3248                 $user = $this->getUser();
3249
3250                 if ( !$user->isLoggedIn() ) {
3251                         // Anons have predictable edit tokens
3252                         return false;
3253                 }
3254                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3255                         return false;
3256                 }
3257
3258                 $title = $this->getTitle();
3259                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3260                 if ( count( $errors ) !== 0 ) {
3261                         return false;
3262                 }
3263
3264                 return true;
3265         }
3266
3267         /**
3268          * @return array Array in format "link name or number => 'link html'".
3269          */
3270         public function getHeadLinksArray() {
3271                 global $wgVersion;
3272
3273                 $tags = [];
3274                 $config = $this->getConfig();
3275
3276                 $canonicalUrl = $this->mCanonicalUrl;
3277
3278                 $tags['meta-generator'] = Html::element( 'meta', [
3279                         'name' => 'generator',
3280                         'content' => "MediaWiki $wgVersion",
3281                 ] );
3282
3283                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3284                         // Per https://w3c.github.io/webappsec-referrer-policy/#unknown-policy-values
3285                         // fallbacks should come before the primary value so we need to reverse the array.
3286                         foreach ( array_reverse( (array)$config->get( 'ReferrerPolicy' ) ) as $i => $policy ) {
3287                                 $tags["meta-referrer-$i"] = Html::element( 'meta', [
3288                                         'name' => 'referrer',
3289                                         'content' => $policy,
3290                                 ] );
3291                         }
3292                 }
3293
3294                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3295                 if ( $p !== 'index,follow' ) {
3296                         // http://www.robotstxt.org/wc/meta-user.html
3297                         // Only show if it's different from the default robots policy
3298                         $tags['meta-robots'] = Html::element( 'meta', [
3299                                 'name' => 'robots',
3300                                 'content' => $p,
3301                         ] );
3302                 }
3303
3304                 foreach ( $this->mMetatags as $tag ) {
3305                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3306                                 $a = 'http-equiv';
3307                                 $tag[0] = substr( $tag[0], 5 );
3308                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3309                                 $a = 'property';
3310                         } else {
3311                                 $a = 'name';
3312                         }
3313                         $tagName = "meta-{$tag[0]}";
3314                         if ( isset( $tags[$tagName] ) ) {
3315                                 $tagName .= $tag[1];
3316                         }
3317                         $tags[$tagName] = Html::element( 'meta',
3318                                 [
3319                                         $a => $tag[0],
3320                                         'content' => $tag[1]
3321                                 ]
3322                         );
3323                 }
3324
3325                 foreach ( $this->mLinktags as $tag ) {
3326                         $tags[] = Html::element( 'link', $tag );
3327                 }
3328
3329                 # Universal edit button
3330                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3331                         $user = $this->getUser();
3332                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3333                                 && ( $this->getTitle()->exists() ||
3334                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3335                         ) {
3336                                 // Original UniversalEditButton
3337                                 $msg = $this->msg( 'edit' )->text();
3338                                 $tags['universal-edit-button'] = Html::element( 'link', [
3339                                         'rel' => 'alternate',
3340                                         'type' => 'application/x-wiki',
3341                                         'title' => $msg,
3342                                         'href' => $this->getTitle()->getEditURL(),
3343                                 ] );
3344                                 // Alternate edit link
3345                                 $tags['alternative-edit'] = Html::element( 'link', [
3346                                         'rel' => 'edit',
3347                                         'title' => $msg,
3348                                         'href' => $this->getTitle()->getEditURL(),
3349                                 ] );
3350                         }
3351                 }
3352
3353                 # Generally the order of the favicon and apple-touch-icon links
3354                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3355                 # uses whichever one appears later in the HTML source. Make sure
3356                 # apple-touch-icon is specified first to avoid this.
3357                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3358                         $tags['apple-touch-icon'] = Html::element( 'link', [
3359                                 'rel' => 'apple-touch-icon',
3360                                 'href' => $config->get( 'AppleTouchIcon' )
3361                         ] );
3362                 }
3363
3364                 if ( $config->get( 'Favicon' ) !== false ) {
3365                         $tags['favicon'] = Html::element( 'link', [
3366                                 'rel' => 'shortcut icon',
3367                                 'href' => $config->get( 'Favicon' )
3368                         ] );
3369                 }
3370
3371                 # OpenSearch description link
3372                 $tags['opensearch'] = Html::element( 'link', [
3373                         'rel' => 'search',
3374                         'type' => 'application/opensearchdescription+xml',
3375                         'href' => wfScript( 'opensearch_desc' ),
3376                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3377                 ] );
3378
3379                 # Real Simple Discovery link, provides auto-discovery information
3380                 # for the MediaWiki API (and potentially additional custom API
3381                 # support such as WordPress or Twitter-compatible APIs for a
3382                 # blogging extension, etc)
3383                 $tags['rsd'] = Html::element( 'link', [
3384                         'rel' => 'EditURI',
3385                         'type' => 'application/rsd+xml',
3386                         // Output a protocol-relative URL here if $wgServer is protocol-relative.
3387                         // Whether RSD accepts relative or protocol-relative URLs is completely
3388                         // undocumented, though.
3389                         'href' => wfExpandUrl( wfAppendQuery(
3390                                 wfScript( 'api' ),
3391                                 [ 'action' => 'rsd' ] ),
3392                                 PROTO_RELATIVE
3393                         ),
3394                 ] );
3395
3396                 # Language variants
3397                 if ( !$config->get( 'DisableLangConversion' ) ) {
3398                         $lang = $this->getTitle()->getPageLanguage();
3399                         if ( $lang->hasVariants() ) {
3400                                 $variants = $lang->getVariants();
3401                                 foreach ( $variants as $variant ) {
3402                                         $tags["variant-$variant"] = Html::element( 'link', [
3403                                                 'rel' => 'alternate',
3404                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3405                                                 'href' => $this->getTitle()->getLocalURL(
3406                                                         [ 'variant' => $variant ] )
3407                                                 ]
3408                                         );
3409                                 }
3410                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3411                                 $tags["variant-x-default"] = Html::element( 'link', [
3412                                         'rel' => 'alternate',
3413                                         'hreflang' => 'x-default',
3414                                         'href' => $this->getTitle()->getLocalURL() ] );
3415                         }
3416                 }
3417
3418                 # Copyright
3419                 if ( $this->copyrightUrl !== null ) {
3420                         $copyright = $this->copyrightUrl;
3421                 } else {
3422                         $copyright = '';
3423                         if ( $config->get( 'RightsPage' ) ) {
3424                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3425
3426                                 if ( $copy ) {
3427                                         $copyright = $copy->getLocalURL();
3428                                 }
3429                         }
3430
3431                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3432                                 $copyright = $config->get( 'RightsUrl' );
3433                         }
3434                 }
3435
3436                 if ( $copyright ) {
3437                         $tags['copyright'] = Html::element( 'link', [
3438                                 'rel' => 'license',
3439                                 'href' => $copyright ]
3440                         );
3441                 }
3442
3443                 # Feeds
3444                 if ( $config->get( 'Feed' ) ) {
3445                         $feedLinks = [];
3446
3447                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3448                                 # Use the page name for the title.  In principle, this could
3449                                 # lead to issues with having the same name for different feeds
3450                                 # corresponding to the same page, but we can't avoid that at
3451                                 # this low a level.
3452
3453                                 $feedLinks[] = $this->feedLink(
3454                                         $format,
3455                                         $link,
3456                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3457                                         $this->msg(
3458                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3459                                         )->text()
3460                                 );
3461                         }
3462
3463                         # Recent changes feed should appear on every page (except recentchanges,
3464                         # that would be redundant). Put it after the per-page feed to avoid
3465                         # changing existing behavior. It's still available, probably via a
3466                         # menu in your browser. Some sites might have a different feed they'd
3467                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3468                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3469                         # If so, use it instead.
3470                         $sitename = $config->get( 'Sitename' );
3471                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3472                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3473                                         // Note, this->feedLink escapes the url.
3474                                         $feedLinks[] = $this->feedLink(
3475                                                 $type,
3476                                                 $feedUrl,
3477                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3478                                         );
3479                                 }
3480                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3481                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3482                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3483                                         $feedLinks[] = $this->feedLink(
3484                                                 $format,
3485                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3486                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3487                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3488                                         );
3489                                 }
3490                         }
3491
3492                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3493                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3494                         # use OutputPage::addFeedLink() instead.
3495                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3496
3497                         $tags += $feedLinks;
3498                 }
3499
3500                 # Canonical URL
3501                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3502                         if ( $canonicalUrl !== false ) {
3503                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3504                         } else {
3505                                 if ( $this->isArticleRelated() ) {
3506                                         // This affects all requests where "setArticleRelated" is true. This is
3507                                         // typically all requests that show content (query title, curid, oldid, diff),
3508                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3509                                         // It does not apply to File pages and Special pages.
3510                                         // 'history' and 'info' actions address page metadata rather than the page
3511                                         // content itself, so they may not be canonicalized to the view page url.
3512                                         // TODO: this ought to be better encapsulated in the Action class.
3513                                         $action = Action::getActionName( $this->getContext() );
3514                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3515                                                 $query = "action={$action}";
3516                                         } else {
3517                                                 $query = '';
3518                                         }
3519                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3520                                 } else {
3521                                         $reqUrl = $this->getRequest()->getRequestURL();
3522                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3523                                 }
3524                         }
3525                 }
3526                 if ( $canonicalUrl !== false ) {
3527                         $tags[] = Html::element( 'link', [
3528                                 'rel' => 'canonical',
3529                                 'href' => $canonicalUrl
3530                         ] );
3531                 }
3532
3533                 // Allow extensions to add, remove and/or otherwise manipulate these links
3534                 // If you want only to *add* <head> links, please use the addHeadItem()
3535                 // (or addHeadItems() for multiple items) method instead.
3536                 // This hook is provided as a last resort for extensions to modify these
3537                 // links before the output is sent to client.
3538                 Hooks::run( 'OutputPageAfterGetHeadLinksArray', [ &$tags, $this ] );
3539
3540                 return $tags;
3541         }
3542
3543         /**
3544          * Generate a "<link rel/>" for a feed.
3545          *
3546          * @param string $type Feed type
3547          * @param string $url URL to the feed
3548          * @param string $text Value of the "title" attribute
3549          * @return string HTML fragment
3550          */
3551         private function feedLink( $type, $url, $text ) {
3552                 return Html::element( 'link', [
3553                         'rel' => 'alternate',
3554                         'type' => "application/$type+xml",
3555                         'title' => $text,
3556                         'href' => $url ]
3557                 );
3558         }
3559
3560         /**
3561          * Add a local or specified stylesheet, with the given media options.
3562          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3563          *
3564          * @param string $style URL to the file
3565          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3566          * @param string $condition For IE conditional comments, specifying an IE version
3567          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3568          */
3569         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3570                 $options = [];
3571                 if ( $media ) {
3572                         $options['media'] = $media;
3573                 }
3574                 if ( $condition ) {
3575                         $options['condition'] = $condition;
3576                 }
3577                 if ( $dir ) {
3578                         $options['dir'] = $dir;
3579                 }
3580                 $this->styles[$style] = $options;
3581         }
3582
3583         /**
3584          * Adds inline CSS styles
3585          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3586          *
3587          * @param mixed $style_css Inline CSS
3588          * @param string $flip Set to 'flip' to flip the CSS if needed
3589          */
3590         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3591                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3592                         # If wanted, and the interface is right-to-left, flip the CSS
3593                         $style_css = CSSJanus::transform( $style_css, true, false );
3594                 }
3595                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3596         }
3597
3598         /**
3599          * Build exempt modules and legacy non-ResourceLoader styles.
3600          *
3601          * @return string|WrappedStringList HTML
3602          */
3603         protected function buildExemptModules() {
3604                 $chunks = [];
3605                 // Things that go after the ResourceLoaderDynamicStyles marker
3606                 $append = [];
3607
3608                 // We want site, private and user styles to override dynamically added styles from
3609                 // general modules, but we want dynamically added styles to override statically added
3610                 // style modules. So the order has to be:
3611                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3612                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3613                 // - ResourceLoaderDynamicStyles marker
3614                 // - site/private/user styles
3615
3616                 // Add legacy styles added through addStyle()/addInlineStyle() here
3617                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3618
3619                 $chunks[] = Html::element(
3620                         'meta',
3621                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3622                 );
3623
3624                 $separateReq = [ 'site.styles', 'user.styles' ];
3625                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3626                         // Combinable modules
3627                         $chunks[] = $this->makeResourceLoaderLink(
3628                                 array_diff( $moduleNames, $separateReq ),
3629                                 ResourceLoaderModule::TYPE_STYLES
3630                         );
3631
3632                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3633                                 // These require their own dedicated request in order to support "@import"
3634                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3635                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3636                                         ResourceLoaderModule::TYPE_STYLES
3637                                 );
3638                         }
3639                 }
3640
3641                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3642         }
3643
3644         /**
3645          * @return array
3646          */
3647         public function buildCssLinksArray() {
3648                 $links = [];
3649
3650                 foreach ( $this->styles as $file => $options ) {
3651                         $link = $this->styleLink( $file, $options );
3652                         if ( $link ) {
3653                                 $links[$file] = $link;
3654                         }
3655                 }
3656                 return $links;
3657         }
3658
3659         /**
3660          * Generate \<link\> tags for stylesheets
3661          *
3662          * @param string $style URL to the file
3663          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3664          * @return string HTML fragment
3665          */
3666         protected function styleLink( $style, array $options ) {
3667                 if ( isset( $options['dir'] ) ) {
3668                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3669                                 return '';
3670                         }
3671                 }
3672
3673                 if ( isset( $options['media'] ) ) {
3674                         $media = self::transformCssMedia( $options['media'] );
3675                         if ( is_null( $media ) ) {
3676                                 return '';
3677                         }
3678                 } else {
3679                         $media = 'all';
3680                 }
3681
3682                 if ( substr( $style, 0, 1 ) == '/' ||
3683                         substr( $style, 0, 5 ) == 'http:' ||
3684                         substr( $style, 0, 6 ) == 'https:' ) {
3685                         $url = $style;
3686                 } else {
3687                         $config = $this->getConfig();
3688                         // Append file hash as query parameter
3689                         $url = self::transformResourcePath(
3690                                 $config,
3691                                 $config->get( 'StylePath' ) . '/' . $style
3692                         );
3693                 }
3694
3695                 $link = Html::linkedStyle( $url, $media );
3696
3697                 if ( isset( $options['condition'] ) ) {
3698                         $condition = htmlspecialchars( $options['condition'] );
3699                         $link = "<!--[if $condition]>$link<![endif]-->";
3700                 }
3701                 return $link;
3702         }
3703
3704         /**
3705          * Transform path to web-accessible static resource.
3706          *
3707          * This is used to add a validation hash as query string.
3708          * This aids various behaviors:
3709          *
3710          * - Put long Cache-Control max-age headers on responses for improved
3711          *   cache performance.
3712          * - Get the correct version of a file as expected by the current page.
3713          * - Instantly get the updated version of a file after deployment.
3714          *
3715          * Avoid using this for urls included in HTML as otherwise clients may get different
3716          * versions of a resource when navigating the site depending on when the page was cached.
3717          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3718          * an external stylesheet).
3719          *
3720          * @since 1.27
3721          * @param Config $config
3722          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3723          * @return string URL
3724          */
3725         public static function transformResourcePath( Config $config, $path ) {
3726                 global $IP;
3727
3728                 $localDir = $IP;
3729                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3730                 if ( $remotePathPrefix === '' ) {
3731                         // The configured base path is required to be empty string for
3732                         // wikis in the domain root
3733                         $remotePath = '/';
3734                 } else {
3735                         $remotePath = $remotePathPrefix;
3736                 }
3737                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3738                         // - Path is outside wgResourceBasePath, ignore.
3739                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3740                         return $path;
3741                 }
3742                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3743                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3744                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3745                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3746                 $uploadPath = $config->get( 'UploadPath' );
3747                 if ( strpos( $path, $uploadPath ) === 0 ) {
3748                         $localDir = $config->get( 'UploadDirectory' );
3749                         $remotePathPrefix = $remotePath = $uploadPath;
3750                 }
3751
3752                 $path = RelPath::getRelativePath( $path, $remotePath );
3753                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3754         }
3755
3756         /**
3757          * Utility method for transformResourceFilePath().
3758          *
3759          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3760          *
3761          * @since 1.27
3762          * @param string $remotePathPrefix URL path prefix that points to $localPath
3763          * @param string $localPath File directory exposed at $remotePath
3764          * @param string $file Path to target file relative to $localPath
3765          * @return string URL
3766          */
3767         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3768                 $hash = md5_file( "$localPath/$file" );
3769                 if ( $hash === false ) {
3770                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3771                         $hash = '';
3772                 }
3773                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3774         }
3775
3776         /**
3777          * Transform "media" attribute based on request parameters
3778          *
3779          * @param string $media Current value of the "media" attribute
3780          * @return string Modified value of the "media" attribute, or null to skip
3781          * this stylesheet
3782          */
3783         public static function transformCssMedia( $media ) {
3784                 global $wgRequest;
3785
3786                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3787                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3788
3789                 // Switch in on-screen display for media testing
3790                 $switches = [
3791                         'printable' => 'print',
3792                         'handheld' => 'handheld',
3793                 ];
3794                 foreach ( $switches as $switch => $targetMedia ) {
3795                         if ( $wgRequest->getBool( $switch ) ) {
3796                                 if ( $media == $targetMedia ) {
3797                                         $media = '';
3798                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3799                                         /* This regex will not attempt to understand a comma-separated media_query_list
3800                                          *
3801                                          * Example supported values for $media:
3802                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3803                                          * Example NOT supported value for $media:
3804                                          * '3d-glasses, screen, print and resolution > 90dpi'
3805                                          *
3806                                          * If it's a print request, we never want any kind of screen stylesheets
3807                                          * If it's a handheld request (currently the only other choice with a switch),
3808                                          * we don't want simple 'screen' but we might want screen queries that
3809                                          * have a max-width or something, so we'll pass all others on and let the
3810                                          * client do the query.
3811                                          */
3812                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3813                                                 return null;
3814                                         }
3815                                 }
3816                         }
3817                 }
3818
3819                 return $media;
3820         }
3821
3822         /**
3823          * Add a wikitext-formatted message to the output.
3824          * This is equivalent to:
3825          *
3826          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3827          */
3828         public function addWikiMsg( /*...*/ ) {
3829                 $args = func_get_args();
3830                 $name = array_shift( $args );
3831                 $this->addWikiMsgArray( $name, $args );
3832         }
3833
3834         /**
3835          * Add a wikitext-formatted message to the output.
3836          * Like addWikiMsg() except the parameters are taken as an array
3837          * instead of a variable argument list.
3838          *
3839          * @param string $name
3840          * @param array $args
3841          */
3842         public function addWikiMsgArray( $name, $args ) {
3843                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3844         }
3845
3846         /**
3847          * This function takes a number of message/argument specifications, wraps them in
3848          * some overall structure, and then parses the result and adds it to the output.
3849          *
3850          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3851          * and so on. The subsequent arguments may be either
3852          * 1) strings, in which case they are message names, or
3853          * 2) arrays, in which case, within each array, the first element is the message
3854          *    name, and subsequent elements are the parameters to that message.
3855          *
3856          * Don't use this for messages that are not in the user's interface language.
3857          *
3858          * For example:
3859          *
3860          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3861          *
3862          * Is equivalent to:
3863          *
3864          *    $wgOut->addWikiText( "<div class='error'>\n"
3865          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3866          *
3867          * The newline after the opening div is needed in some wikitext. See T21226.
3868          *
3869          * @param string $wrap
3870          */
3871         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3872                 $msgSpecs = func_get_args();
3873                 array_shift( $msgSpecs );
3874                 $msgSpecs = array_values( $msgSpecs );
3875                 $s = $wrap;
3876                 foreach ( $msgSpecs as $n => $spec ) {
3877                         if ( is_array( $spec ) ) {
3878                                 $args = $spec;
3879                                 $name = array_shift( $args );
3880                                 if ( isset( $args['options'] ) ) {
3881                                         unset( $args['options'] );
3882                                         wfDeprecated(
3883                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3884                                                 '1.20'
3885                                         );
3886                                 }
3887                         } else {
3888                                 $args = [];
3889                                 $name = $spec;
3890                         }
3891                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3892                 }
3893                 $this->addWikiText( $s );
3894         }
3895
3896         /**
3897          * Whether the output has a table of contents
3898          * @return bool
3899          * @since 1.22
3900          */
3901         public function isTOCEnabled() {
3902                 return $this->mEnableTOC;
3903         }
3904
3905         /**
3906          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3907          * @param bool $flag
3908          * @since 1.23
3909          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3910          */
3911         public function enableSectionEditLinks( $flag = true ) {
3912                 wfDeprecated( __METHOD__, '1.31' );
3913         }
3914
3915         /**
3916          * @return bool
3917          * @since 1.23
3918          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3919          */
3920         public function sectionEditLinksEnabled() {
3921                 wfDeprecated( __METHOD__, '1.31' );
3922                 return true;
3923         }
3924
3925         /**
3926          * Helper function to setup the PHP implementation of OOUI to use in this request.
3927          *
3928          * @since 1.26
3929          * @param String $skinName The Skin name to determine the correct OOUI theme
3930          * @param String $dir Language direction
3931          */
3932         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
3933                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
3934                 $theme = $themes[$skinName] ?? $themes['default'];
3935                 // For example, 'OOUI\WikimediaUITheme'.
3936                 $themeClass = "OOUI\\{$theme}Theme";
3937                 OOUI\Theme::setSingleton( new $themeClass() );
3938                 OOUI\Element::setDefaultDir( $dir );
3939         }
3940
3941         /**
3942          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3943          * MediaWiki and this OutputPage instance.
3944          *
3945          * @since 1.25
3946          */
3947         public function enableOOUI() {
3948                 self::setupOOUI(
3949                         strtolower( $this->getSkin()->getSkinName() ),
3950                         $this->getLanguage()->getDir()
3951                 );
3952                 $this->addModuleStyles( [
3953                         'oojs-ui-core.styles',
3954                         'oojs-ui.styles.indicators',
3955                         'oojs-ui.styles.textures',
3956                         'mediawiki.widgets.styles',
3957                         'oojs-ui.styles.icons-content',
3958                         'oojs-ui.styles.icons-alerts',
3959                         'oojs-ui.styles.icons-interactions',
3960                 ] );
3961         }
3962
3963         /**
3964          * Add Link headers for preloading the wiki's logo.
3965          *
3966          * @since 1.26
3967          */
3968         protected function addLogoPreloadLinkHeaders() {
3969                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
3970
3971                 $tags = [];
3972                 $logosPerDppx = [];
3973                 $logos = [];
3974
3975                 if ( !is_array( $logo ) ) {
3976                         // No media queries required if we only have one variant
3977                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
3978                         return;
3979                 }
3980
3981                 if ( isset( $logo['svg'] ) ) {
3982                         // No media queries required if we only have a 1x and svg variant
3983                         // because all preload-capable browsers support SVGs
3984                         $this->addLinkHeader( '<' . $logo['svg'] . '>;rel=preload;as=image' );
3985                         return;
3986                 }
3987
3988                 foreach ( $logo as $dppx => $src ) {
3989                         // Keys are in this format: "1.5x"
3990                         $dppx = substr( $dppx, 0, -1 );
3991                         $logosPerDppx[$dppx] = $src;
3992                 }
3993
3994                 // Because PHP can't have floats as array keys
3995                 uksort( $logosPerDppx, function ( $a , $b ) {
3996                         $a = floatval( $a );
3997                         $b = floatval( $b );
3998                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
3999                         return $a <=> $b;
4000                 } );
4001
4002                 foreach ( $logosPerDppx as $dppx => $src ) {
4003                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
4004                 }
4005
4006                 $logosCount = count( $logos );
4007                 // Logic must match ResourceLoaderSkinModule:
4008                 // - 1x applies to resolution < 1.5dppx
4009                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
4010                 // - 2x applies to resolution >= 2dppx
4011                 // Note that min-resolution and max-resolution are both inclusive.
4012                 for ( $i = 0; $i < $logosCount; $i++ ) {
4013                         if ( $i === 0 ) {
4014                                 // Smallest dppx
4015                                 // min-resolution is ">=" (larger than or equal to)
4016                                 // "not min-resolution" is essentially "<"
4017                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
4018                         } elseif ( $i !== $logosCount - 1 ) {
4019                                 // In between
4020                                 // Media query expressions can only apply "not" to the entire expression
4021                                 // (e.g. can't express ">= 1.5 and not >= 2).
4022                                 // Workaround: Use <= 1.9999 in place of < 2.
4023                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
4024                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
4025                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
4026                         } else {
4027                                 // Largest dppx
4028                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
4029                         }
4030
4031                         $this->addLinkHeader(
4032                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
4033                         );
4034                 }
4035         }
4036
4037         /**
4038          * Get (and set if not yet set) the CSP nonce.
4039          *
4040          * This value needs to be included in any <script> tags on the
4041          * page.
4042          *
4043          * @return string|bool Nonce or false to mean don't output nonce
4044          * @since 1.32
4045          */
4046         public function getCSPNonce() {
4047                 if ( !ContentSecurityPolicy::isNonceRequired( $this->getConfig() ) ) {
4048                         return false;
4049                 }
4050                 if ( $this->CSPNonce === null ) {
4051                         // XXX It might be expensive to generate randomness
4052                         // on every request, on Windows.
4053                         $rand = random_bytes( 15 );
4054                         $this->CSPNonce = base64_encode( $rand );
4055                 }
4056                 return $this->CSPNonce;
4057         }
4058 }