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