includes/OutputPage.php

   1 <?php
   2 /**
   3  * Preparation for the final page rendering.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use MediaWiki\Linker\LinkTarget;
  24 use MediaWiki\Logger\LoggerFactory;
  25 use MediaWiki\MediaWikiServices;
  26 use MediaWiki\Session\SessionManager;
  27 use Wikimedia\RelPath;
  28 use Wikimedia\WrappedString;
  29 use Wikimedia\WrappedStringList;
  30
  31 /**
  32  * This class should be covered by a general architecture document which does
  33  * not exist as of January 2011.  This is one of the Core classes and should
  34  * be read at least once by any new developers.
  35  *
  36  * This class is used to prepare the final rendering. A skin is then
  37  * applied to the output parameters (links, javascript, html, categories ...).
  38  *
  39  * @todo FIXME: Another class handles sending the whole page to the client.
  40  *
  41  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  42  * in November 2010.
  43  *
  44  * @todo document
  45  */
  46 class OutputPage extends ContextSource {
  47         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  48         protected $mMetatags = [];
  49
  50         /** @var array */
  51         protected $mLinktags = [];
  52
  53         /** @var bool */
  54         protected $mCanonicalUrl = false;
  55
  56         /**
  57          * @var string Should be private - has getter and setter. Contains
  58          *   the HTML title */
  59         public $mPagetitle = '';
  60
  61         /**
  62          * @var string Contains all of the "<body>" content. Should be private we
  63          *   got set/get accessors and the append() method.
  64          */
  65         public $mBodytext = '';
  66
  67         /** @var string Stores contents of "<title>" tag */
  68         private $mHTMLtitle = '';
  69
  70         /**
  71          * @var bool Is the displayed content related to the source of the
  72          *   corresponding wiki article.
  73          */
  74         private $mIsarticle = false;
  75
  76         /** @var bool Stores "article flag" toggle. */
  77         private $mIsArticleRelated = true;
  78
  79         /**
  80          * @var bool We have to set isPrintable(). Some pages should
  81          * never be printed (ex: redirections).
  82          */
  83         private $mPrintable = false;
  84
  85         /**
  86          * @var array Contains the page subtitle. Special pages usually have some
  87          *   links here. Don't confuse with site subtitle added by skins.
  88          */
  89         private $mSubtitle = [];
  90
  91         /** @var string */
  92         public $mRedirect = '';
  93
  94         /** @var int */
  95         protected $mStatusCode;
  96
  97         /**
  98          * @var string Used for sending cache control.
  99          *   The whole caching system should probably be moved into its own class.
 100          */
 101         protected $mLastModified = '';
 102
 103         /** @var array */
 104         protected $mCategoryLinks = [];
 105
 106         /** @var array */
 107         protected $mCategories = [
 108                 'hidden' => [],
 109                 'normal' => [],
 110         ];
 111
 112         /** @var array */
 113         protected $mIndicators = [];
 114
 115         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 116         private $mLanguageLinks = [];
 117
 118         /**
 119          * Used for JavaScript (predates ResourceLoader)
 120          * @todo We should split JS / CSS.
 121          * mScripts content is inserted as is in "<head>" by Skin. This might
 122          * contain either a link to a stylesheet or inline CSS.
 123          */
 124         private $mScripts = '';
 125
 126         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 127         protected $mInlineStyles = '';
 128
 129         /**
 130          * @var string Used by skin template.
 131          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 132          */
 133         public $mPageLinkTitle = '';
 134
 135         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 136         protected $mHeadItems = [];
 137
 138         /** @var array Additional <body> classes; there are also <body> classes from other sources */
 139         protected $mAdditionalBodyClasses = [];
 140
 141         /** @var array */
 142         protected $mModules = [];
 143
 144         /** @var array */
 145         protected $mModuleScripts = [];
 146
 147         /** @var array */
 148         protected $mModuleStyles = [];
 149
 150         /** @var ResourceLoader */
 151         protected $mResourceLoader;
 152
 153         /** @var ResourceLoaderClientHtml */
 154         private $rlClient;
 155
 156         /** @var ResourceLoaderContext */
 157         private $rlClientContext;
 158
 159         /** @var array */
 160         private $rlExemptStyleModules;
 161
 162         /** @var array */
 163         protected $mJsConfigVars = [];
 164
 165         /** @var array */
 166         protected $mTemplateIds = [];
 167
 168         /** @var array */
 169         protected $mImageTimeKeys = [];
 170
 171         /** @var string */
 172         public $mRedirectCode = '';
 173
 174         protected $mFeedLinksAppendQuery = null;
 175
 176         /** @var array
 177          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 178          * @see ResourceLoaderModule::$origin
 179          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 180          */
 181         protected $mAllowedModules = [
 182                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 183         ];
 184
 185         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 186         protected $mDoNothing = false;
 187
 188         // Parser related.
 189
 190         /** @var int */
 191         protected $mContainsNewMagic = 0;
 192
 193         /**
 194          * lazy initialised, use parserOptions()
 195          * @var ParserOptions
 196          */
 197         protected $mParserOptions = null;
 198
 199         /**
 200          * Handles the Atom / RSS links.
 201          * We probably only support Atom in 2011.
 202          * @see $wgAdvertisedFeedTypes
 203          */
 204         private $mFeedLinks = [];
 205
 206         // Gwicke work on squid caching? Roughly from 2003.
 207         protected $mEnableClientCache = true;
 208
 209         /** @var bool Flag if output should only contain the body of the article. */
 210         private $mArticleBodyOnly = false;
 211
 212         /** @var bool */
 213         protected $mNewSectionLink = false;
 214
 215         /** @var bool */
 216         protected $mHideNewSectionLink = false;
 217
 218         /**
 219          * @var bool Comes from the parser. This was probably made to load CSS/JS
 220          * only if we had "<gallery>". Used directly in CategoryPage.php.
 221          * Looks like ResourceLoader can replace this.
 222          */
 223         public $mNoGallery = false;
 224
 225         /** @var string */
 226         private $mPageTitleActionText = '';
 227
 228         /** @var int Cache stuff. Looks like mEnableClientCache */
 229         protected $mCdnMaxage = 0;
 230         /** @var int Upper limit on mCdnMaxage */
 231         protected $mCdnMaxageLimit = INF;
 232
 233         /**
 234          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 235          * be sent. This should be done for pages where edit actions are possible.
 236          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 237          */
 238         protected $mPreventClickjacking = true;
 239
 240         /** @var int To include the variable {{REVISIONID}} */
 241         private $mRevisionId = null;
 242
 243         /** @var string */
 244         private $mRevisionTimestamp = null;
 245
 246         /** @var array */
 247         protected $mFileVersion = null;
 248
 249         /**
 250          * @var array An array of stylesheet filenames (relative from skins path),
 251          * with options for CSS media, IE conditions, and RTL/LTR direction.
 252          * For internal use; add settings in the skin via $this->addStyle()
 253          *
 254          * Style again! This seems like a code duplication since we already have
 255          * mStyles. This is what makes Open Source amazing.
 256          */
 257         protected $styles = [];
 258
 259         private $mIndexPolicy = 'index';
 260         private $mFollowPolicy = 'follow';
 261         private $mVaryHeader = [
 262                 'Accept-Encoding' => [ 'match=gzip' ],
 263         ];
 264
 265         /**
 266          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 267          * of the redirect.
 268          *
 269          * @var Title
 270          */
 271         private $mRedirectedFrom = null;
 272
 273         /**
 274          * Additional key => value data
 275          */
 276         private $mProperties = [];
 277
 278         /**
 279          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 280          */
 281         private $mTarget = null;
 282
 283         /**
 284          * @var bool Whether parser output contains a table of contents
 285          */
 286         private $mEnableTOC = false;
 287
 288         /**
 289          * @var string|null The URL to send in a <link> element with rel=license
 290          */
 291         private $copyrightUrl;
 292
 293         /** @var array Profiling data */
 294         private $limitReportJSData = [];
 295
 296         /** @var array Map Title to Content */
 297         private $contentOverrides = [];
 298
 299         /** @var callable[] */
 300         private $contentOverrideCallbacks = [];
 301
 302         /**
 303          * Link: header contents
 304          */
 305         private $mLinkHeader = [];
 306
 307         /**
 308          * @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 $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 += $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|ResultWrapper
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 += $parserOutput->getLanguageLinks();
1804                 $this->addCategoryLinks( $parserOutput->getCategories() );
1805                 $this->setIndicators( $parserOutput->getIndicators() );
1806                 $this->mNewSectionLink = $parserOutput->getNewSection();
1807                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1808
1809                 if ( !$parserOutput->isCacheable() ) {
1810                         $this->enableClientCache( false );
1811                 }
1812                 $this->mNoGallery = $parserOutput->getNoGallery();
1813                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1814                 $this->addModules( $parserOutput->getModules() );
1815                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1816                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1817                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1818                 $this->mPreventClickjacking = $this->mPreventClickjacking
1819                         || $parserOutput->preventClickjacking();
1820
1821                 // Template versioning...
1822                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1823                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1824                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1825                         } else {
1826                                 $this->mTemplateIds[$ns] = $dbks;
1827                         }
1828                 }
1829                 // File versioning...
1830                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1831                         $this->mImageTimeKeys[$dbk] = $data;
1832                 }
1833
1834                 // Hooks registered in the object
1835                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1836                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1837                         list( $hookName, $data ) = $hookInfo;
1838                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1839                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1840                         }
1841                 }
1842
1843                 // Enable OOUI if requested via ParserOutput
1844                 if ( $parserOutput->getEnableOOUI() ) {
1845                         $this->enableOOUI();
1846                 }
1847
1848                 // Include parser limit report
1849                 if ( !$this->limitReportJSData ) {
1850                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1851                 }
1852
1853                 // Link flags are ignored for now, but may in the future be
1854                 // used to mark individual language links.
1855                 $linkFlags = [];
1856                 // Avoid PHP 7.1 warning of passing $this by reference
1857                 $outputPage = $this;
1858                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1859                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1860
1861                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
1862                 // so that extensions may modify ParserOutput to toggle TOC.
1863                 // This cannot be moved to addParserOutputText because that is not
1864                 // called by EditPage for Preview.
1865                 if ( $parserOutput->getTOCHTML() ) {
1866                         $this->mEnableTOC = true;
1867                 }
1868         }
1869
1870         /**
1871          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1872          * ParserOutput object, without any other metadata.
1873          *
1874          * @since 1.24
1875          * @param ParserOutput $parserOutput
1876          * @param array $poOptions Options to ParserOutput::getText()
1877          */
1878         public function addParserOutputContent( $parserOutput, $poOptions = [] ) {
1879                 $this->addParserOutputText( $parserOutput, $poOptions );
1880
1881                 $this->addModules( $parserOutput->getModules() );
1882                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1883                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1884
1885                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1886         }
1887
1888         /**
1889          * Add the HTML associated with a ParserOutput object, without any metadata.
1890          *
1891          * @since 1.24
1892          * @param ParserOutput $parserOutput
1893          * @param array $poOptions Options to ParserOutput::getText()
1894          */
1895         public function addParserOutputText( $parserOutput, $poOptions = [] ) {
1896                 $text = $parserOutput->getText( $poOptions );
1897                 // Avoid PHP 7.1 warning of passing $this by reference
1898                 $outputPage = $this;
1899                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1900                 $this->addHTML( $text );
1901         }
1902
1903         /**
1904          * Add everything from a ParserOutput object.
1905          *
1906          * @param ParserOutput $parserOutput
1907          * @param array $poOptions Options to ParserOutput::getText()
1908          */
1909         function addParserOutput( $parserOutput, $poOptions = [] ) {
1910                 $this->addParserOutputMetadata( $parserOutput );
1911                 $this->addParserOutputText( $parserOutput, $poOptions );
1912         }
1913
1914         /**
1915          * Add the output of a QuickTemplate to the output buffer
1916          *
1917          * @param QuickTemplate &$template
1918          */
1919         public function addTemplate( &$template ) {
1920                 $this->addHTML( $template->getHTML() );
1921         }
1922
1923         /**
1924          * Parse wikitext and return the HTML.
1925          *
1926          * @param string $text
1927          * @param bool $linestart Is this the start of a line?
1928          * @param bool $interface Use interface language ($wgLang instead of
1929          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1930          *   This also disables LanguageConverter.
1931          * @param Language $language Target language object, will override $interface
1932          * @throws MWException
1933          * @return string HTML
1934          */
1935         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1936                 global $wgParser;
1937
1938                 if ( is_null( $this->getTitle() ) ) {
1939                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1940                 }
1941
1942                 $popts = $this->parserOptions();
1943                 if ( $interface ) {
1944                         $popts->setInterfaceMessage( true );
1945                 }
1946                 if ( $language !== null ) {
1947                         $oldLang = $popts->setTargetLanguage( $language );
1948                 }
1949
1950                 $parserOutput = $wgParser->getFreshParser()->parse(
1951                         $text, $this->getTitle(), $popts,
1952                         $linestart, true, $this->mRevisionId
1953                 );
1954
1955                 if ( $interface ) {
1956                         $popts->setInterfaceMessage( false );
1957                 }
1958                 if ( $language !== null ) {
1959                         $popts->setTargetLanguage( $oldLang );
1960                 }
1961
1962                 return $parserOutput->getText( [
1963                         'enableSectionEditLinks' => false,
1964                 ] );
1965         }
1966
1967         /**
1968          * Parse wikitext, strip paragraphs, and return the HTML.
1969          *
1970          * @param string $text
1971          * @param bool $linestart Is this the start of a line?
1972          * @param bool $interface Use interface language ($wgLang instead of
1973          *   $wgContLang) while parsing language sensitive magic
1974          *   words like GRAMMAR and PLURAL
1975          * @return string HTML
1976          */
1977         public function parseInline( $text, $linestart = true, $interface = false ) {
1978                 $parsed = $this->parse( $text, $linestart, $interface );
1979                 return Parser::stripOuterParagraph( $parsed );
1980         }
1981
1982         /**
1983          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1984          *
1985          * @param int $maxage Maximum cache time on the CDN, in seconds.
1986          */
1987         public function setCdnMaxage( $maxage ) {
1988                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1989         }
1990
1991         /**
1992          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1993          *
1994          * @param int $maxage Maximum cache time on the CDN, in seconds
1995          * @since 1.27
1996          */
1997         public function lowerCdnMaxage( $maxage ) {
1998                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1999                 $this->setCdnMaxage( $this->mCdnMaxage );
2000         }
2001
2002         /**
2003          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
2004          *
2005          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
2006          * the TTL is higher the older the $mtime timestamp is. Essentially, the
2007          * TTL is 90% of the age of the object, subject to the min and max.
2008          *
2009          * @param string|int|float|bool|null $mtime Last-Modified timestamp
2010          * @param int $minTTL Mimimum TTL in seconds [default: 1 minute]
2011          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
2012          * @return int TTL in seconds
2013          * @since 1.28
2014          */
2015         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
2016                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
2017                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
2018
2019                 if ( $mtime === null || $mtime === false ) {
2020                         return $minTTL; // entity does not exist
2021                 }
2022
2023                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
2024                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
2025                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
2026
2027                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2028
2029                 return $adaptiveTTL;
2030         }
2031
2032         /**
2033          * Use enableClientCache(false) to force it to send nocache headers
2034          *
2035          * @param bool $state
2036          *
2037          * @return bool
2038          */
2039         public function enableClientCache( $state ) {
2040                 return wfSetVar( $this->mEnableClientCache, $state );
2041         }
2042
2043         /**
2044          * Get the list of cookies that will influence on the cache
2045          *
2046          * @return array
2047          */
2048         function getCacheVaryCookies() {
2049                 static $cookies;
2050                 if ( $cookies === null ) {
2051                         $config = $this->getConfig();
2052                         $cookies = array_merge(
2053                                 SessionManager::singleton()->getVaryCookies(),
2054                                 [
2055                                         'forceHTTPS',
2056                                 ],
2057                                 $config->get( 'CacheVaryCookies' )
2058                         );
2059                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2060                 }
2061                 return $cookies;
2062         }
2063
2064         /**
2065          * Check if the request has a cache-varying cookie header
2066          * If it does, it's very important that we don't allow public caching
2067          *
2068          * @return bool
2069          */
2070         function haveCacheVaryCookies() {
2071                 $request = $this->getRequest();
2072                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2073                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2074                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2075                                 return true;
2076                         }
2077                 }
2078                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2079                 return false;
2080         }
2081
2082         /**
2083          * Add an HTTP header that will influence on the cache
2084          *
2085          * @param string $header Header name
2086          * @param string[]|null $option Options for the Key header. See
2087          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2088          * for the list of valid options.
2089          */
2090         public function addVaryHeader( $header, array $option = null ) {
2091                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2092                         $this->mVaryHeader[$header] = [];
2093                 }
2094                 if ( !is_array( $option ) ) {
2095                         $option = [];
2096                 }
2097                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2098         }
2099
2100         /**
2101          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2102          * such as Accept-Encoding or Cookie
2103          *
2104          * @return string
2105          */
2106         public function getVaryHeader() {
2107                 // If we vary on cookies, let's make sure it's always included here too.
2108                 if ( $this->getCacheVaryCookies() ) {
2109                         $this->addVaryHeader( 'Cookie' );
2110                 }
2111
2112                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2113                         $this->addVaryHeader( $header, $options );
2114                 }
2115                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2116         }
2117
2118         /**
2119          * Add an HTTP Link: header
2120          *
2121          * @param string $header Header value
2122          */
2123         public function addLinkHeader( $header ) {
2124                 $this->mLinkHeader[] = $header;
2125         }
2126
2127         /**
2128          * Return a Link: header. Based on the values of $mLinkHeader.
2129          *
2130          * @return string
2131          */
2132         public function getLinkHeader() {
2133                 if ( !$this->mLinkHeader ) {
2134                         return false;
2135                 }
2136
2137                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2138         }
2139
2140         /**
2141          * Get a complete Key header
2142          *
2143          * @return string
2144          */
2145         public function getKeyHeader() {
2146                 $cvCookies = $this->getCacheVaryCookies();
2147
2148                 $cookiesOption = [];
2149                 foreach ( $cvCookies as $cookieName ) {
2150                         $cookiesOption[] = 'param=' . $cookieName;
2151                 }
2152                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2153
2154                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2155                         $this->addVaryHeader( $header, $options );
2156                 }
2157
2158                 $headers = [];
2159                 foreach ( $this->mVaryHeader as $header => $option ) {
2160                         $newheader = $header;
2161                         if ( is_array( $option ) && count( $option ) > 0 ) {
2162                                 $newheader .= ';' . implode( ';', $option );
2163                         }
2164                         $headers[] = $newheader;
2165                 }
2166                 $key = 'Key: ' . implode( ',', $headers );
2167
2168                 return $key;
2169         }
2170
2171         /**
2172          * T23672: Add Accept-Language to Vary and Key headers
2173          * if there's no 'variant' parameter existed in GET.
2174          *
2175          * For example:
2176          *   /w/index.php?title=Main_page should always be served; but
2177          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2178          */
2179         function addAcceptLanguage() {
2180                 $title = $this->getTitle();
2181                 if ( !$title instanceof Title ) {
2182                         return;
2183                 }
2184
2185                 $lang = $title->getPageLanguage();
2186                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2187                         $variants = $lang->getVariants();
2188                         $aloption = [];
2189                         foreach ( $variants as $variant ) {
2190                                 if ( $variant === $lang->getCode() ) {
2191                                         continue;
2192                                 } else {
2193                                         $aloption[] = 'substr=' . $variant;
2194
2195                                         // IE and some other browsers use BCP 47 standards in
2196                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2197                                         // We should handle these too.
2198                                         $variantBCP47 = LanguageCode::bcp47( $variant );
2199                                         if ( $variantBCP47 !== $variant ) {
2200                                                 $aloption[] = 'substr=' . $variantBCP47;
2201                                         }
2202                                 }
2203                         }
2204                         $this->addVaryHeader( 'Accept-Language', $aloption );
2205                 }
2206         }
2207
2208         /**
2209          * Set a flag which will cause an X-Frame-Options header appropriate for
2210          * edit pages to be sent. The header value is controlled by
2211          * $wgEditPageFrameOptions.
2212          *
2213          * This is the default for special pages. If you display a CSRF-protected
2214          * form on an ordinary view page, then you need to call this function.
2215          *
2216          * @param bool $enable
2217          */
2218         public function preventClickjacking( $enable = true ) {
2219                 $this->mPreventClickjacking = $enable;
2220         }
2221
2222         /**
2223          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2224          * This can be called from pages which do not contain any CSRF-protected
2225          * HTML form.
2226          */
2227         public function allowClickjacking() {
2228                 $this->mPreventClickjacking = false;
2229         }
2230
2231         /**
2232          * Get the prevent-clickjacking flag
2233          *
2234          * @since 1.24
2235          * @return bool
2236          */
2237         public function getPreventClickjacking() {
2238                 return $this->mPreventClickjacking;
2239         }
2240
2241         /**
2242          * Get the X-Frame-Options header value (without the name part), or false
2243          * if there isn't one. This is used by Skin to determine whether to enable
2244          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2245          *
2246          * @return string|false
2247          */
2248         public function getFrameOptions() {
2249                 $config = $this->getConfig();
2250                 if ( $config->get( 'BreakFrames' ) ) {
2251                         return 'DENY';
2252                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2253                         return $config->get( 'EditPageFrameOptions' );
2254                 }
2255                 return false;
2256         }
2257
2258         /**
2259          * Send cache control HTTP headers
2260          */
2261         public function sendCacheControl() {
2262                 $response = $this->getRequest()->response();
2263                 $config = $this->getConfig();
2264
2265                 $this->addVaryHeader( 'Cookie' );
2266                 $this->addAcceptLanguage();
2267
2268                 # don't serve compressed data to clients who can't handle it
2269                 # maintain different caches for logged-in users and non-logged in ones
2270                 $response->header( $this->getVaryHeader() );
2271
2272                 if ( $config->get( 'UseKeyHeader' ) ) {
2273                         $response->header( $this->getKeyHeader() );
2274                 }
2275
2276                 if ( $this->mEnableClientCache ) {
2277                         if (
2278                                 $config->get( 'UseSquid' ) &&
2279                                 !$response->hasCookies() &&
2280                                 !SessionManager::getGlobalSession()->isPersistent() &&
2281                                 !$this->isPrintable() &&
2282                                 $this->mCdnMaxage != 0 &&
2283                                 !$this->haveCacheVaryCookies()
2284                         ) {
2285                                 if ( $config->get( 'UseESI' ) ) {
2286                                         # We'll purge the proxy cache explicitly, but require end user agents
2287                                         # to revalidate against the proxy on each visit.
2288                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2289                                         wfDebug( __METHOD__ .
2290                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2291                                         # start with a shorter timeout for initial testing
2292                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2293                                         $response->header(
2294                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2295                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2296                                         );
2297                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2298                                 } else {
2299                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2300                                         # to revalidate against the proxy on each visit.
2301                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2302                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2303                                         wfDebug( __METHOD__ .
2304                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2305                                         # start with a shorter timeout for initial testing
2306                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2307                                         $response->header( "Cache-Control: " .
2308                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2309                                 }
2310                         } else {
2311                                 # We do want clients to cache if they can, but they *must* check for updates
2312                                 # on revisiting the page.
2313                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2314                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2315                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2316                         }
2317                         if ( $this->mLastModified ) {
2318                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2319                         }
2320                 } else {
2321                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2322
2323                         # In general, the absence of a last modified header should be enough to prevent
2324                         # the client from using its cache. We send a few other things just to make sure.
2325                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2326                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2327                         $response->header( 'Pragma: no-cache' );
2328                 }
2329         }
2330
2331         /**
2332          * Transfer styles and JavaScript modules from skin.
2333          *
2334          * @param Skin $sk to load modules for
2335          */
2336         public function loadSkinModules( $sk ) {
2337                 foreach ( $sk->getDefaultModules() as $group => $modules ) {
2338                         if ( $group === 'styles' ) {
2339                                 foreach ( $modules as $key => $moduleMembers ) {
2340                                         $this->addModuleStyles( $moduleMembers );
2341                                 }
2342                         } else {
2343                                 $this->addModules( $modules );
2344                         }
2345                 }
2346         }
2347
2348         /**
2349          * Finally, all the text has been munged and accumulated into
2350          * the object, let's actually output it:
2351          *
2352          * @param bool $return Set to true to get the result as a string rather than sending it
2353          * @return string|null
2354          * @throws Exception
2355          * @throws FatalError
2356          * @throws MWException
2357          */
2358         public function output( $return = false ) {
2359                 global $wgContLang;
2360
2361                 if ( $this->mDoNothing ) {
2362                         return $return ? '' : null;
2363                 }
2364
2365                 $response = $this->getRequest()->response();
2366                 $config = $this->getConfig();
2367
2368                 if ( $this->mRedirect != '' ) {
2369                         # Standards require redirect URLs to be absolute
2370                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2371
2372                         $redirect = $this->mRedirect;
2373                         $code = $this->mRedirectCode;
2374
2375                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2376                                 if ( $code == '301' || $code == '303' ) {
2377                                         if ( !$config->get( 'DebugRedirects' ) ) {
2378                                                 $response->statusHeader( $code );
2379                                         }
2380                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2381                                 }
2382                                 if ( $config->get( 'VaryOnXFP' ) ) {
2383                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2384                                 }
2385                                 $this->sendCacheControl();
2386
2387                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2388                                 if ( $config->get( 'DebugRedirects' ) ) {
2389                                         $url = htmlspecialchars( $redirect );
2390                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2391                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2392                                         print "</body>\n</html>\n";
2393                                 } else {
2394                                         $response->header( 'Location: ' . $redirect );
2395                                 }
2396                         }
2397
2398                         return $return ? '' : null;
2399                 } elseif ( $this->mStatusCode ) {
2400                         $response->statusHeader( $this->mStatusCode );
2401                 }
2402
2403                 # Buffer output; final headers may depend on later processing
2404                 ob_start();
2405
2406                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2407                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2408
2409                 if ( !$this->mArticleBodyOnly ) {
2410                         $sk = $this->getSkin();
2411
2412                         if ( $sk->shouldPreloadLogo() ) {
2413                                 $this->addLogoPreloadLinkHeaders();
2414                         }
2415                 }
2416
2417                 $linkHeader = $this->getLinkHeader();
2418                 if ( $linkHeader ) {
2419                         $response->header( $linkHeader );
2420                 }
2421
2422                 // Prevent framing, if requested
2423                 $frameOptions = $this->getFrameOptions();
2424                 if ( $frameOptions ) {
2425                         $response->header( "X-Frame-Options: $frameOptions" );
2426                 }
2427
2428                 ContentSecurityPolicy::sendHeaders( $this );
2429
2430                 if ( $this->mArticleBodyOnly ) {
2431                         echo $this->mBodytext;
2432                 } else {
2433                         // Enable safe mode if requested (T152169)
2434                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2435                                 $this->disallowUserJs();
2436                         }
2437
2438                         $sk = $this->getSkin();
2439                         $this->loadSkinModules( $sk );
2440
2441                         MWDebug::addModules( $this );
2442
2443                         // Avoid PHP 7.1 warning of passing $this by reference
2444                         $outputPage = $this;
2445                         // Hook that allows last minute changes to the output page, e.g.
2446                         // adding of CSS or Javascript by extensions.
2447                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2448
2449                         try {
2450                                 $sk->outputPage();
2451                         } catch ( Exception $e ) {
2452                                 ob_end_clean(); // bug T129657
2453                                 throw $e;
2454                         }
2455                 }
2456
2457                 try {
2458                         // This hook allows last minute changes to final overall output by modifying output buffer
2459                         Hooks::runWithoutAbort( 'AfterFinalPageOutput', [ $this ] );
2460                 } catch ( Exception $e ) {
2461                         ob_end_clean(); // bug T129657
2462                         throw $e;
2463                 }
2464
2465                 $this->sendCacheControl();
2466
2467                 if ( $return ) {
2468                         return ob_get_clean();
2469                 } else {
2470                         ob_end_flush();
2471                         return null;
2472                 }
2473         }
2474
2475         /**
2476          * Prepare this object to display an error page; disable caching and
2477          * indexing, clear the current text and redirect, set the page's title
2478          * and optionally an custom HTML title (content of the "<title>" tag).
2479          *
2480          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2481          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2482          *                   optional, if not passed the "<title>" attribute will be
2483          *                   based on $pageTitle
2484          */
2485         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2486                 $this->setPageTitle( $pageTitle );
2487                 if ( $htmlTitle !== false ) {
2488                         $this->setHTMLTitle( $htmlTitle );
2489                 }
2490                 $this->setRobotPolicy( 'noindex,nofollow' );
2491                 $this->setArticleRelated( false );
2492                 $this->enableClientCache( false );
2493                 $this->mRedirect = '';
2494                 $this->clearSubtitle();
2495                 $this->clearHTML();
2496         }
2497
2498         /**
2499          * Output a standard error page
2500          *
2501          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2502          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2503          * showErrorPage( 'titlemsg', $messageObject );
2504          * showErrorPage( $titleMessageObject, $messageObject );
2505          *
2506          * @param string|Message $title Message key (string) for page title, or a Message object
2507          * @param string|Message $msg Message key (string) for page text, or a Message object
2508          * @param array $params Message parameters; ignored if $msg is a Message object
2509          */
2510         public function showErrorPage( $title, $msg, $params = [] ) {
2511                 if ( !$title instanceof Message ) {
2512                         $title = $this->msg( $title );
2513                 }
2514
2515                 $this->prepareErrorPage( $title );
2516
2517                 if ( $msg instanceof Message ) {
2518                         if ( $params !== [] ) {
2519                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2520                                         . 'is discarded when the $msg argument is a Message object instead of '
2521                                         . 'a string.', E_USER_NOTICE );
2522                         }
2523                         $this->addHTML( $msg->parseAsBlock() );
2524                 } else {
2525                         $this->addWikiMsgArray( $msg, $params );
2526                 }
2527
2528                 $this->returnToMain();
2529         }
2530
2531         /**
2532          * Output a standard permission error page
2533          *
2534          * @param array $errors Error message keys or [key, param...] arrays
2535          * @param string $action Action that was denied or null if unknown
2536          */
2537         public function showPermissionsErrorPage( array $errors, $action = null ) {
2538                 foreach ( $errors as $key => $error ) {
2539                         $errors[$key] = (array)$error;
2540                 }
2541
2542                 // For some action (read, edit, create and upload), display a "login to do this action"
2543                 // error if all of the following conditions are met:
2544                 // 1. the user is not logged in
2545                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2546                 // 3. the error can be avoided simply by logging in
2547                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2548                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2549                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2550                         && ( User::groupHasPermission( 'user', $action )
2551                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2552                 ) {
2553                         $displayReturnto = null;
2554
2555                         # Due to T34276, if a user does not have read permissions,
2556                         # $this->getTitle() will just give Special:Badtitle, which is
2557                         # not especially useful as a returnto parameter. Use the title
2558                         # from the request instead, if there was one.
2559                         $request = $this->getRequest();
2560                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2561                         if ( $action == 'edit' ) {
2562                                 $msg = 'whitelistedittext';
2563                                 $displayReturnto = $returnto;
2564                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2565                                 $msg = 'nocreatetext';
2566                         } elseif ( $action == 'upload' ) {
2567                                 $msg = 'uploadnologintext';
2568                         } else { # Read
2569                                 $msg = 'loginreqpagetext';
2570                                 $displayReturnto = Title::newMainPage();
2571                         }
2572
2573                         $query = [];
2574
2575                         if ( $returnto ) {
2576                                 $query['returnto'] = $returnto->getPrefixedText();
2577
2578                                 if ( !$request->wasPosted() ) {
2579                                         $returntoquery = $request->getValues();
2580                                         unset( $returntoquery['title'] );
2581                                         unset( $returntoquery['returnto'] );
2582                                         unset( $returntoquery['returntoquery'] );
2583                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2584                                 }
2585                         }
2586                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2587                         $loginLink = $linkRenderer->makeKnownLink(
2588                                 SpecialPage::getTitleFor( 'Userlogin' ),
2589                                 $this->msg( 'loginreqlink' )->text(),
2590                                 [],
2591                                 $query
2592                         );
2593
2594                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2595                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2596
2597                         # Don't return to a page the user can't read otherwise
2598                         # we'll end up in a pointless loop
2599                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2600                                 $this->returnToMain( null, $displayReturnto );
2601                         }
2602                 } else {
2603                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2604                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2605                 }
2606         }
2607
2608         /**
2609          * Display an error page indicating that a given version of MediaWiki is
2610          * required to use it
2611          *
2612          * @param mixed $version The version of MediaWiki needed to use the page
2613          */
2614         public function versionRequired( $version ) {
2615                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2616
2617                 $this->addWikiMsg( 'versionrequiredtext', $version );
2618                 $this->returnToMain();
2619         }
2620
2621         /**
2622          * Format a list of error messages
2623          *
2624          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2625          * @param string $action Action that was denied or null if unknown
2626          * @return string The wikitext error-messages, formatted into a list.
2627          */
2628         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2629                 if ( $action == null ) {
2630                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2631                 } else {
2632                         $action_desc = $this->msg( "action-$action" )->plain();
2633                         $text = $this->msg(
2634                                 'permissionserrorstext-withaction',
2635                                 count( $errors ),
2636                                 $action_desc
2637                         )->plain() . "\n\n";
2638                 }
2639
2640                 if ( count( $errors ) > 1 ) {
2641                         $text .= '<ul class="permissions-errors">' . "\n";
2642
2643                         foreach ( $errors as $error ) {
2644                                 $text .= '<li>';
2645                                 $text .= $this->msg( ...$error )->plain();
2646                                 $text .= "</li>\n";
2647                         }
2648                         $text .= '</ul>';
2649                 } else {
2650                         $text .= "<div class=\"permissions-errors\">\n" .
2651                                         $this->msg( ...reset( $errors ) )->plain() .
2652                                         "\n</div>";
2653                 }
2654
2655                 return $text;
2656         }
2657
2658         /**
2659          * Show a warning about replica DB lag
2660          *
2661          * If the lag is higher than $wgSlaveLagCritical seconds,
2662          * then the warning is a bit more obvious. If the lag is
2663          * lower than $wgSlaveLagWarning, then no warning is shown.
2664          *
2665          * @param int $lag Slave lag
2666          */
2667         public function showLagWarning( $lag ) {
2668                 $config = $this->getConfig();
2669                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2670                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2671                         $message = $lag < $config->get( 'SlaveLagCritical' )
2672                                 ? 'lag-warn-normal'
2673                                 : 'lag-warn-high';
2674                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2675                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2676                 }
2677         }
2678
2679         public function showFatalError( $message ) {
2680                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2681
2682                 $this->addHTML( $message );
2683         }
2684
2685         public function showUnexpectedValueError( $name, $val ) {
2686                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2687         }
2688
2689         public function showFileCopyError( $old, $new ) {
2690                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2691         }
2692
2693         public function showFileRenameError( $old, $new ) {
2694                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2695         }
2696
2697         public function showFileDeleteError( $name ) {
2698                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2699         }
2700
2701         public function showFileNotFoundError( $name ) {
2702                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2703         }
2704
2705         /**
2706          * Add a "return to" link pointing to a specified title
2707          *
2708          * @param Title $title Title to link
2709          * @param array $query Query string parameters
2710          * @param string $text Text of the link (input is not escaped)
2711          * @param array $options Options array to pass to Linker
2712          */
2713         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2714                 $linkRenderer = MediaWikiServices::getInstance()
2715                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
2716                 $link = $this->msg( 'returnto' )->rawParams(
2717                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
2718                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2719         }
2720
2721         /**
2722          * Add a "return to" link pointing to a specified title,
2723          * or the title indicated in the request, or else the main page
2724          *
2725          * @param mixed $unused
2726          * @param Title|string $returnto Title or String to return to
2727          * @param string $returntoquery Query string for the return to link
2728          */
2729         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2730                 if ( $returnto == null ) {
2731                         $returnto = $this->getRequest()->getText( 'returnto' );
2732                 }
2733
2734                 if ( $returntoquery == null ) {
2735                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2736                 }
2737
2738                 if ( $returnto === '' ) {
2739                         $returnto = Title::newMainPage();
2740                 }
2741
2742                 if ( is_object( $returnto ) ) {
2743                         $titleObj = $returnto;
2744                 } else {
2745                         $titleObj = Title::newFromText( $returnto );
2746                 }
2747                 // We don't want people to return to external interwiki. That
2748                 // might potentially be used as part of a phishing scheme
2749                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
2750                         $titleObj = Title::newMainPage();
2751                 }
2752
2753                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2754         }
2755
2756         private function getRlClientContext() {
2757                 if ( !$this->rlClientContext ) {
2758                         $query = ResourceLoader::makeLoaderQuery(
2759                                 [], // modules; not relevant
2760                                 $this->getLanguage()->getCode(),
2761                                 $this->getSkin()->getSkinName(),
2762                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2763                                 null, // version; not relevant
2764                                 ResourceLoader::inDebugMode(),
2765                                 null, // only; not relevant
2766                                 $this->isPrintable(),
2767                                 $this->getRequest()->getBool( 'handheld' )
2768                         );
2769                         $this->rlClientContext = new ResourceLoaderContext(
2770                                 $this->getResourceLoader(),
2771                                 new FauxRequest( $query )
2772                         );
2773                         if ( $this->contentOverrideCallbacks ) {
2774                                 $this->rlClientContext = new DerivativeResourceLoaderContext( $this->rlClientContext );
2775                                 $this->rlClientContext->setContentOverrideCallback( function ( Title $title ) {
2776                                         foreach ( $this->contentOverrideCallbacks as $callback ) {
2777                                                 $content = call_user_func( $callback, $title );
2778                                                 if ( $content !== null ) {
2779                                                         return $content;
2780                                                 }
2781                                         }
2782                                         return null;
2783                                 } );
2784                         }
2785                 }
2786                 return $this->rlClientContext;
2787         }
2788
2789         /**
2790          * Call this to freeze the module queue and JS config and create a formatter.
2791          *
2792          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2793          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2794          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2795          * the module filters retroactively. Skins and extension hooks may also add modules until very
2796          * late in the request lifecycle.
2797          *
2798          * @return ResourceLoaderClientHtml
2799          */
2800         public function getRlClient() {
2801                 if ( !$this->rlClient ) {
2802                         $context = $this->getRlClientContext();
2803                         $rl = $this->getResourceLoader();
2804                         $this->addModules( [
2805                                 'user',
2806                                 'user.options',
2807                                 'user.tokens',
2808                         ] );
2809                         $this->addModuleStyles( [
2810                                 'site.styles',
2811                                 'noscript',
2812                                 'user.styles',
2813                         ] );
2814                         $this->getSkin()->setupSkinUserCss( $this );
2815
2816                         // Prepare exempt modules for buildExemptModules()
2817                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2818                         $exemptStates = [];
2819                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2820
2821                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2822                         // Separate user-specific batch for improved cache-hit ratio.
2823                         $userBatch = [ 'user.styles', 'user' ];
2824                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2825                         $dbr = wfGetDB( DB_REPLICA );
2826                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2827                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2828
2829                         // Filter out modules handled by buildExemptModules()
2830                         $moduleStyles = array_filter( $moduleStyles,
2831                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2832                                         $module = $rl->getModule( $name );
2833                                         if ( $module ) {
2834                                                 $group = $module->getGroup();
2835                                                 if ( isset( $exemptGroups[$group] ) ) {
2836                                                         $exemptStates[$name] = 'ready';
2837                                                         if ( !$module->isKnownEmpty( $context ) ) {
2838                                                                 // E.g. Don't output empty <styles>
2839                                                                 $exemptGroups[$group][] = $name;
2840                                                         }
2841                                                         return false;
2842                                                 }
2843                                         }
2844                                         return true;
2845                                 }
2846                         );
2847                         $this->rlExemptStyleModules = $exemptGroups;
2848
2849                         $rlClient = new ResourceLoaderClientHtml( $context, [
2850                                 'target' => $this->getTarget(),
2851                                 'nonce' => $this->getCSPNonce(),
2852                                 // When 'safemode', disallowUserJs(), or reduceAllowedModules() is used
2853                                 // to only restrict modules to ORIGIN_CORE (ie. disallow ORIGIN_USER), the list of
2854                                 // modules enqueud for loading on this page is filtered to just those.
2855                                 // However, to make sure we also apply the restriction to dynamic dependencies and
2856                                 // lazy-loaded modules at run-time on the client-side, pass 'safemode' down to the
2857                                 // StartupModule so that the client-side registry will not contain any restricted
2858                                 // modules either. (T152169, T185303)
2859                                 'safemode' => ( $this->getAllowedModules( ResourceLoaderModule::TYPE_COMBINED )
2860                                         <= ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
2861                                 ) ? '1' : null,
2862                         ] );
2863                         $rlClient->setConfig( $this->getJSVars() );
2864                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2865                         $rlClient->setModuleStyles( $moduleStyles );
2866                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2867                         $rlClient->setExemptStates( $exemptStates );
2868                         $this->rlClient = $rlClient;
2869                 }
2870                 return $this->rlClient;
2871         }
2872
2873         /**
2874          * @param Skin $sk The given Skin
2875          * @param bool $includeStyle Unused
2876          * @return string The doctype, opening "<html>", and head element.
2877          */
2878         public function headElement( Skin $sk, $includeStyle = true ) {
2879                 global $wgContLang;
2880
2881                 $userdir = $this->getLanguage()->getDir();
2882                 $sitedir = $wgContLang->getDir();
2883
2884                 $pieces = [];
2885                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2886                         $this->getRlClient()->getDocumentAttributes(),
2887                         $sk->getHtmlElementAttributes()
2888                 ) );
2889                 $pieces[] = Html::openElement( 'head' );
2890
2891                 if ( $this->getHTMLTitle() == '' ) {
2892                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2893                 }
2894
2895                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2896                         // Add <meta charset="UTF-8">
2897                         // This should be before <title> since it defines the charset used by
2898                         // text including the text inside <title>.
2899                         // The spec recommends defining XHTML5's charset using the XML declaration
2900                         // instead of meta.
2901                         // Our XML declaration is output by Html::htmlHeader.
2902                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2903                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2904                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2905                 }
2906
2907                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2908                 $pieces[] = $this->getRlClient()->getHeadHtml();
2909                 $pieces[] = $this->buildExemptModules();
2910                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2911                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2912
2913                 // Use an IE conditional comment to serve the script only to old IE
2914                 $pieces[] = '<!--[if lt IE 9]>' .
2915                         ResourceLoaderClientHtml::makeLoad(
2916                                 ResourceLoaderContext::newDummyContext(),
2917                                 [ 'html5shiv' ],
2918                                 ResourceLoaderModule::TYPE_SCRIPTS,
2919                                 [ 'sync' => true ],
2920                                 $this->getCSPNonce()
2921                         ) .
2922                         '<![endif]-->';
2923
2924                 $pieces[] = Html::closeElement( 'head' );
2925
2926                 $bodyClasses = $this->mAdditionalBodyClasses;
2927                 $bodyClasses[] = 'mediawiki';
2928
2929                 # Classes for LTR/RTL directionality support
2930                 $bodyClasses[] = $userdir;
2931                 $bodyClasses[] = "sitedir-$sitedir";
2932
2933                 $underline = $this->getUser()->getOption( 'underline' );
2934                 if ( $underline < 2 ) {
2935                         // The following classes can be used here:
2936                         // * mw-underline-always
2937                         // * mw-underline-never
2938                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2939                 }
2940
2941                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2942                         # A <body> class is probably not the best way to do this . . .
2943                         $bodyClasses[] = 'capitalize-all-nouns';
2944                 }
2945
2946                 // Parser feature migration class
2947                 // The idea is that this will eventually be removed, after the wikitext
2948                 // which requires it is cleaned up.
2949                 $bodyClasses[] = 'mw-hide-empty-elt';
2950
2951                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2952                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2953                 $bodyClasses[] =
2954                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2955
2956                 $bodyAttrs = [];
2957                 // While the implode() is not strictly needed, it's used for backwards compatibility
2958                 // (this used to be built as a string and hooks likely still expect that).
2959                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2960
2961                 // Allow skins and extensions to add body attributes they need
2962                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2963                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2964
2965                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2966
2967                 return self::combineWrappedStrings( $pieces );
2968         }
2969
2970         /**
2971          * Get a ResourceLoader object associated with this OutputPage
2972          *
2973          * @return ResourceLoader
2974          */
2975         public function getResourceLoader() {
2976                 if ( is_null( $this->mResourceLoader ) ) {
2977                         $this->mResourceLoader = new ResourceLoader(
2978                                 $this->getConfig(),
2979                                 LoggerFactory::getInstance( 'resourceloader' )
2980                         );
2981                 }
2982                 return $this->mResourceLoader;
2983         }
2984
2985         /**
2986          * Explicily load or embed modules on a page.
2987          *
2988          * @param array|string $modules One or more module names
2989          * @param string $only ResourceLoaderModule TYPE_ class constant
2990          * @param array $extraQuery [optional] Array with extra query parameters for the request
2991          * @return string|WrappedStringList HTML
2992          */
2993         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2994                 // Apply 'target' and 'origin' filters
2995                 $modules = $this->filterModules( (array)$modules, null, $only );
2996
2997                 return ResourceLoaderClientHtml::makeLoad(
2998                         $this->getRlClientContext(),
2999                         $modules,
3000                         $only,
3001                         $extraQuery,
3002                         $this->getCSPNonce()
3003                 );
3004         }
3005
3006         /**
3007          * Combine WrappedString chunks and filter out empty ones
3008          *
3009          * @param array $chunks
3010          * @return string|WrappedStringList HTML
3011          */
3012         protected static function combineWrappedStrings( array $chunks ) {
3013                 // Filter out empty values
3014                 $chunks = array_filter( $chunks, 'strlen' );
3015                 return WrappedString::join( "\n", $chunks );
3016         }
3017
3018         /**
3019          * JS stuff to put at the bottom of the `<body>`.
3020          * These are legacy scripts ($this->mScripts), and user JS.
3021          *
3022          * @return string|WrappedStringList HTML
3023          */
3024         public function getBottomScripts() {
3025                 $chunks = [];
3026                 $chunks[] = $this->getRlClient()->getBodyHtml();
3027
3028                 // Legacy non-ResourceLoader scripts
3029                 $chunks[] = $this->mScripts;
3030
3031                 if ( $this->limitReportJSData ) {
3032                         $chunks[] = ResourceLoader::makeInlineScript(
3033                                 ResourceLoader::makeConfigSetScript(
3034                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3035                                 ),
3036                                 $this->getCSPNonce()
3037                         );
3038                 }
3039
3040                 return self::combineWrappedStrings( $chunks );
3041         }
3042
3043         /**
3044          * Get the javascript config vars to include on this page
3045          *
3046          * @return array Array of javascript config vars
3047          * @since 1.23
3048          */
3049         public function getJsConfigVars() {
3050                 return $this->mJsConfigVars;
3051         }
3052
3053         /**
3054          * Add one or more variables to be set in mw.config in JavaScript
3055          *
3056          * @param string|array $keys Key or array of key/value pairs
3057          * @param mixed $value [optional] Value of the configuration variable
3058          */
3059         public function addJsConfigVars( $keys, $value = null ) {
3060                 if ( is_array( $keys ) ) {
3061                         foreach ( $keys as $key => $value ) {
3062                                 $this->mJsConfigVars[$key] = $value;
3063                         }
3064                         return;
3065                 }
3066
3067                 $this->mJsConfigVars[$keys] = $value;
3068         }
3069
3070         /**
3071          * Get an array containing the variables to be set in mw.config in JavaScript.
3072          *
3073          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3074          * - in other words, page-independent/site-wide variables (without state).
3075          * You will only be adding bloat to the html page and causing page caches to
3076          * have to be purged on configuration changes.
3077          * @return array
3078          */
3079         public function getJSVars() {
3080                 global $wgContLang;
3081
3082                 $curRevisionId = 0;
3083                 $articleId = 0;
3084                 $canonicalSpecialPageName = false; # T23115
3085
3086                 $title = $this->getTitle();
3087                 $ns = $title->getNamespace();
3088                 $canonicalNamespace = MWNamespace::exists( $ns )
3089                         ? MWNamespace::getCanonicalName( $ns )
3090                         : $title->getNsText();
3091
3092                 $sk = $this->getSkin();
3093                 // Get the relevant title so that AJAX features can use the correct page name
3094                 // when making API requests from certain special pages (T36972).
3095                 $relevantTitle = $sk->getRelevantTitle();
3096                 $relevantUser = $sk->getRelevantUser();
3097
3098                 if ( $ns == NS_SPECIAL ) {
3099                         list( $canonicalSpecialPageName, /*...*/ ) =
3100                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3101                 } elseif ( $this->canUseWikiPage() ) {
3102                         $wikiPage = $this->getWikiPage();
3103                         $curRevisionId = $wikiPage->getLatest();
3104                         $articleId = $wikiPage->getId();
3105                 }
3106
3107                 $lang = $title->getPageViewLanguage();
3108
3109                 // Pre-process information
3110                 $separatorTransTable = $lang->separatorTransformTable();
3111                 $separatorTransTable = $separatorTransTable ?: [];
3112                 $compactSeparatorTransTable = [
3113                         implode( "\t", array_keys( $separatorTransTable ) ),
3114                         implode( "\t", $separatorTransTable ),
3115                 ];
3116                 $digitTransTable = $lang->digitTransformTable();
3117                 $digitTransTable = $digitTransTable ?: [];
3118                 $compactDigitTransTable = [
3119                         implode( "\t", array_keys( $digitTransTable ) ),
3120                         implode( "\t", $digitTransTable ),
3121                 ];
3122
3123                 $user = $this->getUser();
3124
3125                 $vars = [
3126                         'wgCanonicalNamespace' => $canonicalNamespace,
3127                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3128                         'wgNamespaceNumber' => $title->getNamespace(),
3129                         'wgPageName' => $title->getPrefixedDBkey(),
3130                         'wgTitle' => $title->getText(),
3131                         'wgCurRevisionId' => $curRevisionId,
3132                         'wgRevisionId' => (int)$this->getRevisionId(),
3133                         'wgArticleId' => $articleId,
3134                         'wgIsArticle' => $this->isArticle(),
3135                         'wgIsRedirect' => $title->isRedirect(),
3136                         'wgAction' => Action::getActionName( $this->getContext() ),
3137                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3138                         'wgUserGroups' => $user->getEffectiveGroups(),
3139                         'wgCategories' => $this->getCategories(),
3140                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3141                         'wgPageContentLanguage' => $lang->getCode(),
3142                         'wgPageContentModel' => $title->getContentModel(),
3143                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3144                         'wgDigitTransformTable' => $compactDigitTransTable,
3145                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3146                         'wgMonthNames' => $lang->getMonthNamesArray(),
3147                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3148                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3149                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3150                         'wgRequestId' => WebRequest::getRequestId(),
3151                 ];
3152
3153                 if ( $user->isLoggedIn() ) {
3154                         $vars['wgUserId'] = $user->getId();
3155                         $vars['wgUserEditCount'] = $user->getEditCount();
3156                         $userReg = $user->getRegistration();
3157                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3158                         // Get the revision ID of the oldest new message on the user's talk
3159                         // page. This can be used for constructing new message alerts on
3160                         // the client side.
3161                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3162                 }
3163
3164                 if ( $wgContLang->hasVariants() ) {
3165                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3166                 }
3167                 // Same test as SkinTemplate
3168                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3169                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3170
3171                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3172                         && $relevantTitle->quickUserCan( 'edit', $user )
3173                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3174
3175                 foreach ( $title->getRestrictionTypes() as $type ) {
3176                         // Following keys are set in $vars:
3177                         // wgRestrictionCreate, wgRestrictionEdit, wgRestrictionMove, wgRestrictionUpload
3178                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3179                 }
3180
3181                 if ( $title->isMainPage() ) {
3182                         $vars['wgIsMainPage'] = true;
3183                 }
3184
3185                 if ( $this->mRedirectedFrom ) {
3186                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3187                 }
3188
3189                 if ( $relevantUser ) {
3190                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3191                 }
3192
3193                 // Allow extensions to add their custom variables to the mw.config map.
3194                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3195                 // page-dependant but site-wide (without state).
3196                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3197                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3198
3199                 // Merge in variables from addJsConfigVars last
3200                 return array_merge( $vars, $this->getJsConfigVars() );
3201         }
3202
3203         /**
3204          * To make it harder for someone to slip a user a fake
3205          * JavaScript or CSS preview, a random token
3206          * is associated with the login session. If it's not
3207          * passed back with the preview request, we won't render
3208          * the code.
3209          *
3210          * @return bool
3211          */
3212         public function userCanPreview() {
3213                 $request = $this->getRequest();
3214                 if (
3215                         $request->getVal( 'action' ) !== 'submit' ||
3216                         !$request->wasPosted()
3217                 ) {
3218                         return false;
3219                 }
3220
3221                 $user = $this->getUser();
3222
3223                 if ( !$user->isLoggedIn() ) {
3224                         // Anons have predictable edit tokens
3225                         return false;
3226                 }
3227                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3228                         return false;
3229                 }
3230
3231                 $title = $this->getTitle();
3232                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3233                 if ( count( $errors ) !== 0 ) {
3234                         return false;
3235                 }
3236
3237                 return true;
3238         }
3239
3240         /**
3241          * @return array Array in format "link name or number => 'link html'".
3242          */
3243         public function getHeadLinksArray() {
3244                 global $wgVersion;
3245
3246                 $tags = [];
3247                 $config = $this->getConfig();
3248
3249                 $canonicalUrl = $this->mCanonicalUrl;
3250
3251                 $tags['meta-generator'] = Html::element( 'meta', [
3252                         'name' => 'generator',
3253                         'content' => "MediaWiki $wgVersion",
3254                 ] );
3255
3256                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3257                         // Per https://w3c.github.io/webappsec-referrer-policy/#unknown-policy-values
3258                         // fallbacks should come before the primary value so we need to reverse the array.
3259                         foreach ( array_reverse( (array)$config->get( 'ReferrerPolicy' ) ) as $i => $policy ) {
3260                                 $tags["meta-referrer-$i"] = Html::element( 'meta', [
3261                                         'name' => 'referrer',
3262                                         'content' => $policy,
3263                                 ] );
3264                         }
3265                 }
3266
3267                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3268                 if ( $p !== 'index,follow' ) {
3269                         // http://www.robotstxt.org/wc/meta-user.html
3270                         // Only show if it's different from the default robots policy
3271                         $tags['meta-robots'] = Html::element( 'meta', [
3272                                 'name' => 'robots',
3273                                 'content' => $p,
3274                         ] );
3275                 }
3276
3277                 foreach ( $this->mMetatags as $tag ) {
3278                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3279                                 $a = 'http-equiv';
3280                                 $tag[0] = substr( $tag[0], 5 );
3281                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3282                                 $a = 'property';
3283                         } else {
3284                                 $a = 'name';
3285                         }
3286                         $tagName = "meta-{$tag[0]}";
3287                         if ( isset( $tags[$tagName] ) ) {
3288                                 $tagName .= $tag[1];
3289                         }
3290                         $tags[$tagName] = Html::element( 'meta',
3291                                 [
3292                                         $a => $tag[0],
3293                                         'content' => $tag[1]
3294                                 ]
3295                         );
3296                 }
3297
3298                 foreach ( $this->mLinktags as $tag ) {
3299                         $tags[] = Html::element( 'link', $tag );
3300                 }
3301
3302                 # Universal edit button
3303                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3304                         $user = $this->getUser();
3305                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3306                                 && ( $this->getTitle()->exists() ||
3307                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3308                         ) {
3309                                 // Original UniversalEditButton
3310                                 $msg = $this->msg( 'edit' )->text();
3311                                 $tags['universal-edit-button'] = Html::element( 'link', [
3312                                         'rel' => 'alternate',
3313                                         'type' => 'application/x-wiki',
3314                                         'title' => $msg,
3315                                         'href' => $this->getTitle()->getEditURL(),
3316                                 ] );
3317                                 // Alternate edit link
3318                                 $tags['alternative-edit'] = Html::element( 'link', [
3319                                         'rel' => 'edit',
3320                                         'title' => $msg,
3321                                         'href' => $this->getTitle()->getEditURL(),
3322                                 ] );
3323                         }
3324                 }
3325
3326                 # Generally the order of the favicon and apple-touch-icon links
3327                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3328                 # uses whichever one appears later in the HTML source. Make sure
3329                 # apple-touch-icon is specified first to avoid this.
3330                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3331                         $tags['apple-touch-icon'] = Html::element( 'link', [
3332                                 'rel' => 'apple-touch-icon',
3333                                 'href' => $config->get( 'AppleTouchIcon' )
3334                         ] );
3335                 }
3336
3337                 if ( $config->get( 'Favicon' ) !== false ) {
3338                         $tags['favicon'] = Html::element( 'link', [
3339                                 'rel' => 'shortcut icon',
3340                                 'href' => $config->get( 'Favicon' )
3341                         ] );
3342                 }
3343
3344                 # OpenSearch description link
3345                 $tags['opensearch'] = Html::element( 'link', [
3346                         'rel' => 'search',
3347                         'type' => 'application/opensearchdescription+xml',
3348                         'href' => wfScript( 'opensearch_desc' ),
3349                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3350                 ] );
3351
3352                 # Real Simple Discovery link, provides auto-discovery information
3353                 # for the MediaWiki API (and potentially additional custom API
3354                 # support such as WordPress or Twitter-compatible APIs for a
3355                 # blogging extension, etc)
3356                 $tags['rsd'] = Html::element( 'link', [
3357                         'rel' => 'EditURI',
3358                         'type' => 'application/rsd+xml',
3359                         // Output a protocol-relative URL here if $wgServer is protocol-relative.
3360                         // Whether RSD accepts relative or protocol-relative URLs is completely
3361                         // undocumented, though.
3362                         'href' => wfExpandUrl( wfAppendQuery(
3363                                 wfScript( 'api' ),
3364                                 [ 'action' => 'rsd' ] ),
3365                                 PROTO_RELATIVE
3366                         ),
3367                 ] );
3368
3369                 # Language variants
3370                 if ( !$config->get( 'DisableLangConversion' ) ) {
3371                         $lang = $this->getTitle()->getPageLanguage();
3372                         if ( $lang->hasVariants() ) {
3373                                 $variants = $lang->getVariants();
3374                                 foreach ( $variants as $variant ) {
3375                                         $tags["variant-$variant"] = Html::element( 'link', [
3376                                                 'rel' => 'alternate',
3377                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3378                                                 'href' => $this->getTitle()->getLocalURL(
3379                                                         [ 'variant' => $variant ] )
3380                                                 ]
3381                                         );
3382                                 }
3383                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3384                                 $tags["variant-x-default"] = Html::element( 'link', [
3385                                         'rel' => 'alternate',
3386                                         'hreflang' => 'x-default',
3387                                         'href' => $this->getTitle()->getLocalURL() ] );
3388                         }
3389                 }
3390
3391                 # Copyright
3392                 if ( $this->copyrightUrl !== null ) {
3393                         $copyright = $this->copyrightUrl;
3394                 } else {
3395                         $copyright = '';
3396                         if ( $config->get( 'RightsPage' ) ) {
3397                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3398
3399                                 if ( $copy ) {
3400                                         $copyright = $copy->getLocalURL();
3401                                 }
3402                         }
3403
3404                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3405                                 $copyright = $config->get( 'RightsUrl' );
3406                         }
3407                 }
3408
3409                 if ( $copyright ) {
3410                         $tags['copyright'] = Html::element( 'link', [
3411                                 'rel' => 'license',
3412                                 'href' => $copyright ]
3413                         );
3414                 }
3415
3416                 # Feeds
3417                 if ( $config->get( 'Feed' ) ) {
3418                         $feedLinks = [];
3419
3420                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3421                                 # Use the page name for the title.  In principle, this could
3422                                 # lead to issues with having the same name for different feeds
3423                                 # corresponding to the same page, but we can't avoid that at
3424                                 # this low a level.
3425
3426                                 $feedLinks[] = $this->feedLink(
3427                                         $format,
3428                                         $link,
3429                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3430                                         $this->msg(
3431                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3432                                         )->text()
3433                                 );
3434                         }
3435
3436                         # Recent changes feed should appear on every page (except recentchanges,
3437                         # that would be redundant). Put it after the per-page feed to avoid
3438                         # changing existing behavior. It's still available, probably via a
3439                         # menu in your browser. Some sites might have a different feed they'd
3440                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3441                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3442                         # If so, use it instead.
3443                         $sitename = $config->get( 'Sitename' );
3444                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3445                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3446                                         // Note, this->feedLink escapes the url.
3447                                         $feedLinks[] = $this->feedLink(
3448                                                 $type,
3449                                                 $feedUrl,
3450                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3451                                         );
3452                                 }
3453                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3454                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3455                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3456                                         $feedLinks[] = $this->feedLink(
3457                                                 $format,
3458                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3459                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3460                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3461                                         );
3462                                 }
3463                         }
3464
3465                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3466                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3467                         # use OutputPage::addFeedLink() instead.
3468                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3469
3470                         $tags += $feedLinks;
3471                 }
3472
3473                 # Canonical URL
3474                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3475                         if ( $canonicalUrl !== false ) {
3476                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3477                         } else {
3478                                 if ( $this->isArticleRelated() ) {
3479                                         // This affects all requests where "setArticleRelated" is true. This is
3480                                         // typically all requests that show content (query title, curid, oldid, diff),
3481                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3482                                         // It does not apply to File pages and Special pages.
3483                                         // 'history' and 'info' actions address page metadata rather than the page
3484                                         // content itself, so they may not be canonicalized to the view page url.
3485                                         // TODO: this ought to be better encapsulated in the Action class.
3486                                         $action = Action::getActionName( $this->getContext() );
3487                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3488                                                 $query = "action={$action}";
3489                                         } else {
3490                                                 $query = '';
3491                                         }
3492                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3493                                 } else {
3494                                         $reqUrl = $this->getRequest()->getRequestURL();
3495                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3496                                 }
3497                         }
3498                 }
3499                 if ( $canonicalUrl !== false ) {
3500                         $tags[] = Html::element( 'link', [
3501                                 'rel' => 'canonical',
3502                                 'href' => $canonicalUrl
3503                         ] );
3504                 }
3505
3506                 return $tags;
3507         }
3508
3509         /**
3510          * Generate a "<link rel/>" for a feed.
3511          *
3512          * @param string $type Feed type
3513          * @param string $url URL to the feed
3514          * @param string $text Value of the "title" attribute
3515          * @return string HTML fragment
3516          */
3517         private function feedLink( $type, $url, $text ) {
3518                 return Html::element( 'link', [
3519                         'rel' => 'alternate',
3520                         'type' => "application/$type+xml",
3521                         'title' => $text,
3522                         'href' => $url ]
3523                 );
3524         }
3525
3526         /**
3527          * Add a local or specified stylesheet, with the given media options.
3528          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3529          *
3530          * @param string $style URL to the file
3531          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3532          * @param string $condition For IE conditional comments, specifying an IE version
3533          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3534          */
3535         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3536                 $options = [];
3537                 if ( $media ) {
3538                         $options['media'] = $media;
3539                 }
3540                 if ( $condition ) {
3541                         $options['condition'] = $condition;
3542                 }
3543                 if ( $dir ) {
3544                         $options['dir'] = $dir;
3545                 }
3546                 $this->styles[$style] = $options;
3547         }
3548
3549         /**
3550          * Adds inline CSS styles
3551          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3552          *
3553          * @param mixed $style_css Inline CSS
3554          * @param string $flip Set to 'flip' to flip the CSS if needed
3555          */
3556         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3557                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3558                         # If wanted, and the interface is right-to-left, flip the CSS
3559                         $style_css = CSSJanus::transform( $style_css, true, false );
3560                 }
3561                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3562         }
3563
3564         /**
3565          * Build exempt modules and legacy non-ResourceLoader styles.
3566          *
3567          * @return string|WrappedStringList HTML
3568          */
3569         protected function buildExemptModules() {
3570                 $chunks = [];
3571                 // Things that go after the ResourceLoaderDynamicStyles marker
3572                 $append = [];
3573
3574                 // We want site, private and user styles to override dynamically added styles from
3575                 // general modules, but we want dynamically added styles to override statically added
3576                 // style modules. So the order has to be:
3577                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3578                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3579                 // - ResourceLoaderDynamicStyles marker
3580                 // - site/private/user styles
3581
3582                 // Add legacy styles added through addStyle()/addInlineStyle() here
3583                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3584
3585                 $chunks[] = Html::element(
3586                         'meta',
3587                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3588                 );
3589
3590                 $separateReq = [ 'site.styles', 'user.styles' ];
3591                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3592                         // Combinable modules
3593                         $chunks[] = $this->makeResourceLoaderLink(
3594                                 array_diff( $moduleNames, $separateReq ),
3595                                 ResourceLoaderModule::TYPE_STYLES
3596                         );
3597
3598                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3599                                 // These require their own dedicated request in order to support "@import"
3600                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3601                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3602                                         ResourceLoaderModule::TYPE_STYLES
3603                                 );
3604                         }
3605                 }
3606
3607                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3608         }
3609
3610         /**
3611          * @return array
3612          */
3613         public function buildCssLinksArray() {
3614                 $links = [];
3615
3616                 foreach ( $this->styles as $file => $options ) {
3617                         $link = $this->styleLink( $file, $options );
3618                         if ( $link ) {
3619                                 $links[$file] = $link;
3620                         }
3621                 }
3622                 return $links;
3623         }
3624
3625         /**
3626          * Generate \<link\> tags for stylesheets
3627          *
3628          * @param string $style URL to the file
3629          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3630          * @return string HTML fragment
3631          */
3632         protected function styleLink( $style, array $options ) {
3633                 if ( isset( $options['dir'] ) ) {
3634                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3635                                 return '';
3636                         }
3637                 }
3638
3639                 if ( isset( $options['media'] ) ) {
3640                         $media = self::transformCssMedia( $options['media'] );
3641                         if ( is_null( $media ) ) {
3642                                 return '';
3643                         }
3644                 } else {
3645                         $media = 'all';
3646                 }
3647
3648                 if ( substr( $style, 0, 1 ) == '/' ||
3649                         substr( $style, 0, 5 ) == 'http:' ||
3650                         substr( $style, 0, 6 ) == 'https:' ) {
3651                         $url = $style;
3652                 } else {
3653                         $config = $this->getConfig();
3654                         // Append file hash as query parameter
3655                         $url = self::transformResourcePath(
3656                                 $config,
3657                                 $config->get( 'StylePath' ) . '/' . $style
3658                         );
3659                 }
3660
3661                 $link = Html::linkedStyle( $url, $media );
3662
3663                 if ( isset( $options['condition'] ) ) {
3664                         $condition = htmlspecialchars( $options['condition'] );
3665                         $link = "<!--[if $condition]>$link<![endif]-->";
3666                 }
3667                 return $link;
3668         }
3669
3670         /**
3671          * Transform path to web-accessible static resource.
3672          *
3673          * This is used to add a validation hash as query string.
3674          * This aids various behaviors:
3675          *
3676          * - Put long Cache-Control max-age headers on responses for improved
3677          *   cache performance.
3678          * - Get the correct version of a file as expected by the current page.
3679          * - Instantly get the updated version of a file after deployment.
3680          *
3681          * Avoid using this for urls included in HTML as otherwise clients may get different
3682          * versions of a resource when navigating the site depending on when the page was cached.
3683          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3684          * an external stylesheet).
3685          *
3686          * @since 1.27
3687          * @param Config $config
3688          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3689          * @return string URL
3690          */
3691         public static function transformResourcePath( Config $config, $path ) {
3692                 global $IP;
3693
3694                 $localDir = $IP;
3695                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3696                 if ( $remotePathPrefix === '' ) {
3697                         // The configured base path is required to be empty string for
3698                         // wikis in the domain root
3699                         $remotePath = '/';
3700                 } else {
3701                         $remotePath = $remotePathPrefix;
3702                 }
3703                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3704                         // - Path is outside wgResourceBasePath, ignore.
3705                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3706                         return $path;
3707                 }
3708                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3709                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3710                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3711                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3712                 $uploadPath = $config->get( 'UploadPath' );
3713                 if ( strpos( $path, $uploadPath ) === 0 ) {
3714                         $localDir = $config->get( 'UploadDirectory' );
3715                         $remotePathPrefix = $remotePath = $uploadPath;
3716                 }
3717
3718                 $path = RelPath::getRelativePath( $path, $remotePath );
3719                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3720         }
3721
3722         /**
3723          * Utility method for transformResourceFilePath().
3724          *
3725          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3726          *
3727          * @since 1.27
3728          * @param string $remotePathPrefix URL path prefix that points to $localPath
3729          * @param string $localPath File directory exposed at $remotePath
3730          * @param string $file Path to target file relative to $localPath
3731          * @return string URL
3732          */
3733         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3734                 $hash = md5_file( "$localPath/$file" );
3735                 if ( $hash === false ) {
3736                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3737                         $hash = '';
3738                 }
3739                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3740         }
3741
3742         /**
3743          * Transform "media" attribute based on request parameters
3744          *
3745          * @param string $media Current value of the "media" attribute
3746          * @return string Modified value of the "media" attribute, or null to skip
3747          * this stylesheet
3748          */
3749         public static function transformCssMedia( $media ) {
3750                 global $wgRequest;
3751
3752                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3753                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3754
3755                 // Switch in on-screen display for media testing
3756                 $switches = [
3757                         'printable' => 'print',
3758                         'handheld' => 'handheld',
3759                 ];
3760                 foreach ( $switches as $switch => $targetMedia ) {
3761                         if ( $wgRequest->getBool( $switch ) ) {
3762                                 if ( $media == $targetMedia ) {
3763                                         $media = '';
3764                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3765                                         /* This regex will not attempt to understand a comma-separated media_query_list
3766                                          *
3767                                          * Example supported values for $media:
3768                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3769                                          * Example NOT supported value for $media:
3770                                          * '3d-glasses, screen, print and resolution > 90dpi'
3771                                          *
3772                                          * If it's a print request, we never want any kind of screen stylesheets
3773                                          * If it's a handheld request (currently the only other choice with a switch),
3774                                          * we don't want simple 'screen' but we might want screen queries that
3775                                          * have a max-width or something, so we'll pass all others on and let the
3776                                          * client do the query.
3777                                          */
3778                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3779                                                 return null;
3780                                         }
3781                                 }
3782                         }
3783                 }
3784
3785                 return $media;
3786         }
3787
3788         /**
3789          * Add a wikitext-formatted message to the output.
3790          * This is equivalent to:
3791          *
3792          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3793          */
3794         public function addWikiMsg( /*...*/ ) {
3795                 $args = func_get_args();
3796                 $name = array_shift( $args );
3797                 $this->addWikiMsgArray( $name, $args );
3798         }
3799
3800         /**
3801          * Add a wikitext-formatted message to the output.
3802          * Like addWikiMsg() except the parameters are taken as an array
3803          * instead of a variable argument list.
3804          *
3805          * @param string $name
3806          * @param array $args
3807          */
3808         public function addWikiMsgArray( $name, $args ) {
3809                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3810         }
3811
3812         /**
3813          * This function takes a number of message/argument specifications, wraps them in
3814          * some overall structure, and then parses the result and adds it to the output.
3815          *
3816          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3817          * and so on. The subsequent arguments may be either
3818          * 1) strings, in which case they are message names, or
3819          * 2) arrays, in which case, within each array, the first element is the message
3820          *    name, and subsequent elements are the parameters to that message.
3821          *
3822          * Don't use this for messages that are not in the user's interface language.
3823          *
3824          * For example:
3825          *
3826          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3827          *
3828          * Is equivalent to:
3829          *
3830          *    $wgOut->addWikiText( "<div class='error'>\n"
3831          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3832          *
3833          * The newline after the opening div is needed in some wikitext. See T21226.
3834          *
3835          * @param string $wrap
3836          */
3837         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3838                 $msgSpecs = func_get_args();
3839                 array_shift( $msgSpecs );
3840                 $msgSpecs = array_values( $msgSpecs );
3841                 $s = $wrap;
3842                 foreach ( $msgSpecs as $n => $spec ) {
3843                         if ( is_array( $spec ) ) {
3844                                 $args = $spec;
3845                                 $name = array_shift( $args );
3846                                 if ( isset( $args['options'] ) ) {
3847                                         unset( $args['options'] );
3848                                         wfDeprecated(
3849                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3850                                                 '1.20'
3851                                         );
3852                                 }
3853                         } else {
3854                                 $args = [];
3855                                 $name = $spec;
3856                         }
3857                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3858                 }
3859                 $this->addWikiText( $s );
3860         }
3861
3862         /**
3863          * Whether the output has a table of contents
3864          * @return bool
3865          * @since 1.22
3866          */
3867         public function isTOCEnabled() {
3868                 return $this->mEnableTOC;
3869         }
3870
3871         /**
3872          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3873          * @param bool $flag
3874          * @since 1.23
3875          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3876          */
3877         public function enableSectionEditLinks( $flag = true ) {
3878                 wfDeprecated( __METHOD__, '1.31' );
3879         }
3880
3881         /**
3882          * @return bool
3883          * @since 1.23
3884          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3885          */
3886         public function sectionEditLinksEnabled() {
3887                 wfDeprecated( __METHOD__, '1.31' );
3888                 return true;
3889         }
3890
3891         /**
3892          * Helper function to setup the PHP implementation of OOUI to use in this request.
3893          *
3894          * @since 1.26
3895          * @param String $skinName The Skin name to determine the correct OOUI theme
3896          * @param String $dir Language direction
3897          */
3898         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
3899                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
3900                 $theme = $themes[$skinName] ?? $themes['default'];
3901                 // For example, 'OOUI\WikimediaUITheme'.
3902                 $themeClass = "OOUI\\{$theme}Theme";
3903                 OOUI\Theme::setSingleton( new $themeClass() );
3904                 OOUI\Element::setDefaultDir( $dir );
3905         }
3906
3907         /**
3908          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3909          * MediaWiki and this OutputPage instance.
3910          *
3911          * @since 1.25
3912          */
3913         public function enableOOUI() {
3914                 self::setupOOUI(
3915                         strtolower( $this->getSkin()->getSkinName() ),
3916                         $this->getLanguage()->getDir()
3917                 );
3918                 $this->addModuleStyles( [
3919                         'oojs-ui-core.styles',
3920                         'oojs-ui.styles.indicators',
3921                         'oojs-ui.styles.textures',
3922                         'mediawiki.widgets.styles',
3923                         'oojs-ui.styles.icons-content',
3924                         'oojs-ui.styles.icons-alerts',
3925                         'oojs-ui.styles.icons-interactions',
3926                 ] );
3927         }
3928
3929         /**
3930          * Add Link headers for preloading the wiki's logo.
3931          *
3932          * @since 1.26
3933          */
3934         protected function addLogoPreloadLinkHeaders() {
3935                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
3936
3937                 $tags = [];
3938                 $logosPerDppx = [];
3939                 $logos = [];
3940
3941                 if ( !is_array( $logo ) ) {
3942                         // No media queries required if we only have one variant
3943                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
3944                         return;
3945                 }
3946
3947                 if ( isset( $logo['svg'] ) ) {
3948                         // No media queries required if we only have a 1x and svg variant
3949                         // because all preload-capable browsers support SVGs
3950                         $this->addLinkHeader( '<' . $logo['svg'] . '>;rel=preload;as=image' );
3951                         return;
3952                 }
3953
3954                 foreach ( $logo as $dppx => $src ) {
3955                         // Keys are in this format: "1.5x"
3956                         $dppx = substr( $dppx, 0, -1 );
3957                         $logosPerDppx[$dppx] = $src;
3958                 }
3959
3960                 // Because PHP can't have floats as array keys
3961                 uksort( $logosPerDppx, function ( $a , $b ) {
3962                         $a = floatval( $a );
3963                         $b = floatval( $b );
3964                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
3965                         return $a <=> $b;
3966                 } );
3967
3968                 foreach ( $logosPerDppx as $dppx => $src ) {
3969                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
3970                 }
3971
3972                 $logosCount = count( $logos );
3973                 // Logic must match ResourceLoaderSkinModule:
3974                 // - 1x applies to resolution < 1.5dppx
3975                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
3976                 // - 2x applies to resolution >= 2dppx
3977                 // Note that min-resolution and max-resolution are both inclusive.
3978                 for ( $i = 0; $i < $logosCount; $i++ ) {
3979                         if ( $i === 0 ) {
3980                                 // Smallest dppx
3981                                 // min-resolution is ">=" (larger than or equal to)
3982                                 // "not min-resolution" is essentially "<"
3983                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
3984                         } elseif ( $i !== $logosCount - 1 ) {
3985                                 // In between
3986                                 // Media query expressions can only apply "not" to the entire expression
3987                                 // (e.g. can't express ">= 1.5 and not >= 2).
3988                                 // Workaround: Use <= 1.9999 in place of < 2.
3989                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
3990                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
3991                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
3992                         } else {
3993                                 // Largest dppx
3994                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
3995                         }
3996
3997                         $this->addLinkHeader(
3998                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
3999                         );
4000                 }
4001         }
4002
4003         /**
4004          * Get (and set if not yet set) the CSP nonce.
4005          *
4006          * This value needs to be included in any <script> tags on the
4007          * page.
4008          *
4009          * @return string|bool Nonce or false to mean don't output nonce
4010          * @since 1.32
4011          */
4012         public function getCSPNonce() {
4013                 if ( !ContentSecurityPolicy::isEnabled( $this->getConfig() ) ) {
4014                         return false;
4015                 }
4016                 if ( $this->CSPNonce === null ) {
4017                         // XXX It might be expensive to generate randomness
4018                         // on every request, on Windows.
4019                         $rand = random_bytes( 15 );
4020                         $this->CSPNonce = base64_encode( $rand );
4021                 }
4022                 return $this->CSPNonce;
4023         }
4024 }