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\Logger\LoggerFactory;
  24 use MediaWiki\MediaWikiServices;
  25 use MediaWiki\Session\SessionManager;
  26 use Wikimedia\RelPath;
  27 use Wikimedia\WrappedString;
  28 use Wikimedia\WrappedStringList;
  29
  30 /**
  31  * This class should be covered by a general architecture document which does
  32  * not exist as of January 2011.  This is one of the Core classes and should
  33  * be read at least once by any new developers.
  34  *
  35  * This class is used to prepare the final rendering. A skin is then
  36  * applied to the output parameters (links, javascript, html, categories ...).
  37  *
  38  * @todo FIXME: Another class handles sending the whole page to the client.
  39  *
  40  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  41  * in November 2010.
  42  *
  43  * @todo document
  44  */
  45 class OutputPage extends ContextSource {
  46         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  47         protected $mMetatags = [];
  48
  49         /** @var array */
  50         protected $mLinktags = [];
  51
  52         /** @var bool */
  53         protected $mCanonicalUrl = false;
  54
  55         /**
  56          * @var string Should be private - has getter and setter. Contains
  57          *   the HTML title */
  58         public $mPagetitle = '';
  59
  60         /**
  61          * @var string Contains all of the "<body>" content. Should be private we
  62          *   got set/get accessors and the append() method.
  63          */
  64         public $mBodytext = '';
  65
  66         /** @var string Stores contents of "<title>" tag */
  67         private $mHTMLtitle = '';
  68
  69         /**
  70          * @var bool Is the displayed content related to the source of the
  71          *   corresponding wiki article.
  72          */
  73         private $mIsarticle = false;
  74
  75         /** @var bool Stores "article flag" toggle. */
  76         private $mIsArticleRelated = true;
  77
  78         /**
  79          * @var bool We have to set isPrintable(). Some pages should
  80          * never be printed (ex: redirections).
  81          */
  82         private $mPrintable = false;
  83
  84         /**
  85          * @var array Contains the page subtitle. Special pages usually have some
  86          *   links here. Don't confuse with site subtitle added by skins.
  87          */
  88         private $mSubtitle = [];
  89
  90         /** @var string */
  91         public $mRedirect = '';
  92
  93         /** @var int */
  94         protected $mStatusCode;
  95
  96         /**
  97          * @var string Used for sending cache control.
  98          *   The whole caching system should probably be moved into its own class.
  99          */
 100         protected $mLastModified = '';
 101
 102         /** @var array */
 103         protected $mCategoryLinks = [];
 104
 105         /** @var array */
 106         protected $mCategories = [
 107                 'hidden' => [],
 108                 'normal' => [],
 109         ];
 110
 111         /** @var array */
 112         protected $mIndicators = [];
 113
 114         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 115         private $mLanguageLinks = [];
 116
 117         /**
 118          * Used for JavaScript (predates ResourceLoader)
 119          * @todo We should split JS / CSS.
 120          * mScripts content is inserted as is in "<head>" by Skin. This might
 121          * contain either a link to a stylesheet or inline CSS.
 122          */
 123         private $mScripts = '';
 124
 125         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 126         protected $mInlineStyles = '';
 127
 128         /**
 129          * @var string Used by skin template.
 130          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 131          */
 132         public $mPageLinkTitle = '';
 133
 134         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 135         protected $mHeadItems = [];
 136
 137         /** @var array Additional <body> classes; there are also <body> classes from other sources */
 138         protected $mAdditionalBodyClasses = [];
 139
 140         /** @var array */
 141         protected $mModules = [];
 142
 143         /** @var array */
 144         protected $mModuleScripts = [];
 145
 146         /** @var array */
 147         protected $mModuleStyles = [];
 148
 149         /** @var ResourceLoader */
 150         protected $mResourceLoader;
 151
 152         /** @var ResourceLoaderClientHtml */
 153         private $rlClient;
 154
 155         /** @var ResourceLoaderContext */
 156         private $rlClientContext;
 157
 158         /** @var string */
 159         private $rlUserModuleState;
 160
 161         /** @var array */
 162         private $rlExemptStyleModules;
 163
 164         /** @var array */
 165         protected $mJsConfigVars = [];
 166
 167         /** @var array */
 168         protected $mTemplateIds = [];
 169
 170         /** @var array */
 171         protected $mImageTimeKeys = [];
 172
 173         /** @var string */
 174         public $mRedirectCode = '';
 175
 176         protected $mFeedLinksAppendQuery = null;
 177
 178         /** @var array
 179          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 180          * @see ResourceLoaderModule::$origin
 181          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 182          */
 183         protected $mAllowedModules = [
 184                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 185         ];
 186
 187         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 188         protected $mDoNothing = false;
 189
 190         // Parser related.
 191
 192         /** @var int */
 193         protected $mContainsNewMagic = 0;
 194
 195         /**
 196          * lazy initialised, use parserOptions()
 197          * @var ParserOptions
 198          */
 199         protected $mParserOptions = null;
 200
 201         /**
 202          * Handles the Atom / RSS links.
 203          * We probably only support Atom in 2011.
 204          * @see $wgAdvertisedFeedTypes
 205          */
 206         private $mFeedLinks = [];
 207
 208         // Gwicke work on squid caching? Roughly from 2003.
 209         protected $mEnableClientCache = true;
 210
 211         /** @var bool Flag if output should only contain the body of the article. */
 212         private $mArticleBodyOnly = false;
 213
 214         /** @var bool */
 215         protected $mNewSectionLink = false;
 216
 217         /** @var bool */
 218         protected $mHideNewSectionLink = false;
 219
 220         /**
 221          * @var bool Comes from the parser. This was probably made to load CSS/JS
 222          * only if we had "<gallery>". Used directly in CategoryPage.php.
 223          * Looks like ResourceLoader can replace this.
 224          */
 225         public $mNoGallery = false;
 226
 227         /** @var string */
 228         private $mPageTitleActionText = '';
 229
 230         /** @var int Cache stuff. Looks like mEnableClientCache */
 231         protected $mCdnMaxage = 0;
 232         /** @var int Upper limit on mCdnMaxage */
 233         protected $mCdnMaxageLimit = INF;
 234
 235         /**
 236          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 237          * be sent. This should be done for pages where edit actions are possible.
 238          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 239          */
 240         protected $mPreventClickjacking = true;
 241
 242         /** @var int To include the variable {{REVISIONID}} */
 243         private $mRevisionId = null;
 244
 245         /** @var string */
 246         private $mRevisionTimestamp = null;
 247
 248         /** @var array */
 249         protected $mFileVersion = null;
 250
 251         /**
 252          * @var array An array of stylesheet filenames (relative from skins path),
 253          * with options for CSS media, IE conditions, and RTL/LTR direction.
 254          * For internal use; add settings in the skin via $this->addStyle()
 255          *
 256          * Style again! This seems like a code duplication since we already have
 257          * mStyles. This is what makes Open Source amazing.
 258          */
 259         protected $styles = [];
 260
 261         private $mIndexPolicy = 'index';
 262         private $mFollowPolicy = 'follow';
 263         private $mVaryHeader = [
 264                 'Accept-Encoding' => [ 'match=gzip' ],
 265         ];
 266
 267         /**
 268          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 269          * of the redirect.
 270          *
 271          * @var Title
 272          */
 273         private $mRedirectedFrom = null;
 274
 275         /**
 276          * Additional key => value data
 277          */
 278         private $mProperties = [];
 279
 280         /**
 281          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 282          */
 283         private $mTarget = null;
 284
 285         /**
 286          * @var bool Whether parser output contains a table of contents
 287          */
 288         private $mEnableTOC = false;
 289
 290         /**
 291          * @var bool Whether parser output should contain section edit links
 292          */
 293         private $mEnableSectionEditLinks = true;
 294
 295         /**
 296          * @var string|null The URL to send in a <link> element with rel=license
 297          */
 298         private $copyrightUrl;
 299
 300         /** @var array Profiling data */
 301         private $limitReportJSData = [];
 302
 303         /**
 304          * Link: header contents
 305          */
 306         private $mLinkHeader = [];
 307
 308         /**
 309          * Constructor for OutputPage. This should not be called directly.
 310          * Instead a new RequestContext should be created and it will implicitly create
 311          * a OutputPage tied to that context.
 312          * @param IContextSource $context
 313          */
 314         function __construct( IContextSource $context ) {
 315                 $this->setContext( $context );
 316         }
 317
 318         /**
 319          * Redirect to $url rather than displaying the normal page
 320          *
 321          * @param string $url
 322          * @param string $responsecode HTTP status code
 323          */
 324         public function redirect( $url, $responsecode = '302' ) {
 325                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 326                 $this->mRedirect = str_replace( "\n", '', $url );
 327                 $this->mRedirectCode = $responsecode;
 328         }
 329
 330         /**
 331          * Get the URL to redirect to, or an empty string if not redirect URL set
 332          *
 333          * @return string
 334          */
 335         public function getRedirect() {
 336                 return $this->mRedirect;
 337         }
 338
 339         /**
 340          * Set the copyright URL to send with the output.
 341          * Empty string to omit, null to reset.
 342          *
 343          * @since 1.26
 344          *
 345          * @param string|null $url
 346          */
 347         public function setCopyrightUrl( $url ) {
 348                 $this->copyrightUrl = $url;
 349         }
 350
 351         /**
 352          * Set the HTTP status code to send with the output.
 353          *
 354          * @param int $statusCode
 355          */
 356         public function setStatusCode( $statusCode ) {
 357                 $this->mStatusCode = $statusCode;
 358         }
 359
 360         /**
 361          * Add a new "<meta>" tag
 362          * To add an http-equiv meta tag, precede the name with "http:"
 363          *
 364          * @param string $name Name of the meta tag
 365          * @param string $val Value of the meta tag
 366          */
 367         function addMeta( $name, $val ) {
 368                 array_push( $this->mMetatags, [ $name, $val ] );
 369         }
 370
 371         /**
 372          * Returns the current <meta> tags
 373          *
 374          * @since 1.25
 375          * @return array
 376          */
 377         public function getMetaTags() {
 378                 return $this->mMetatags;
 379         }
 380
 381         /**
 382          * Add a new \<link\> tag to the page header.
 383          *
 384          * Note: use setCanonicalUrl() for rel=canonical.
 385          *
 386          * @param array $linkarr Associative array of attributes.
 387          */
 388         function addLink( array $linkarr ) {
 389                 array_push( $this->mLinktags, $linkarr );
 390         }
 391
 392         /**
 393          * Returns the current <link> tags
 394          *
 395          * @since 1.25
 396          * @return array
 397          */
 398         public function getLinkTags() {
 399                 return $this->mLinktags;
 400         }
 401
 402         /**
 403          * Add a new \<link\> with "rel" attribute set to "meta"
 404          *
 405          * @param array $linkarr Associative array mapping attribute names to their
 406          *                 values, both keys and values will be escaped, and the
 407          *                 "rel" attribute will be automatically added
 408          */
 409         function addMetadataLink( array $linkarr ) {
 410                 $linkarr['rel'] = $this->getMetadataAttribute();
 411                 $this->addLink( $linkarr );
 412         }
 413
 414         /**
 415          * Set the URL to be used for the <link rel=canonical>. This should be used
 416          * in preference to addLink(), to avoid duplicate link tags.
 417          * @param string $url
 418          */
 419         function setCanonicalUrl( $url ) {
 420                 $this->mCanonicalUrl = $url;
 421         }
 422
 423         /**
 424          * Returns the URL to be used for the <link rel=canonical> if
 425          * one is set.
 426          *
 427          * @since 1.25
 428          * @return bool|string
 429          */
 430         public function getCanonicalUrl() {
 431                 return $this->mCanonicalUrl;
 432         }
 433
 434         /**
 435          * Get the value of the "rel" attribute for metadata links
 436          *
 437          * @return string
 438          */
 439         public function getMetadataAttribute() {
 440                 # note: buggy CC software only reads first "meta" link
 441                 static $haveMeta = false;
 442                 if ( $haveMeta ) {
 443                         return 'alternate meta';
 444                 } else {
 445                         $haveMeta = true;
 446                         return 'meta';
 447                 }
 448         }
 449
 450         /**
 451          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 452          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 453          * if possible.
 454          *
 455          * @param string $script Raw HTML
 456          */
 457         function addScript( $script ) {
 458                 $this->mScripts .= $script;
 459         }
 460
 461         /**
 462          * Add a JavaScript file out of skins/common, or a given relative path.
 463          * Internal use only. Use OutputPage::addModules() if possible.
 464          *
 465          * @param string $file Filename in skins/common or complete on-server path
 466          *              (/foo/bar.js)
 467          * @param string $version Style version of the file. Defaults to $wgStyleVersion
 468          */
 469         public function addScriptFile( $file, $version = null ) {
 470                 // See if $file parameter is an absolute URL or begins with a slash
 471                 if ( substr( $file, 0, 1 ) == '/' || preg_match( '#^[a-z]*://#i', $file ) ) {
 472                         $path = $file;
 473                 } else {
 474                         $path = $this->getConfig()->get( 'StylePath' ) . "/common/{$file}";
 475                 }
 476                 if ( is_null( $version ) ) {
 477                         $version = $this->getConfig()->get( 'StyleVersion' );
 478                 }
 479                 $this->addScript( Html::linkedScript( wfAppendQuery( $path, $version ) ) );
 480         }
 481
 482         /**
 483          * Add a self-contained script tag with the given contents
 484          * Internal use only. Use OutputPage::addModules() if possible.
 485          *
 486          * @param string $script JavaScript text, no script tags
 487          */
 488         public function addInlineScript( $script ) {
 489                 $this->mScripts .= Html::inlineScript( $script );
 490         }
 491
 492         /**
 493          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 494          * which are no longer registered (eg a page is cached before an extension is disabled)
 495          * @param array $modules
 496          * @param string|null $position Unused
 497          * @param string $type
 498          * @return array
 499          */
 500         protected function filterModules( array $modules, $position = null,
 501                 $type = ResourceLoaderModule::TYPE_COMBINED
 502         ) {
 503                 $resourceLoader = $this->getResourceLoader();
 504                 $filteredModules = [];
 505                 foreach ( $modules as $val ) {
 506                         $module = $resourceLoader->getModule( $val );
 507                         if ( $module instanceof ResourceLoaderModule
 508                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 509                         ) {
 510                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 511                                         $this->warnModuleTargetFilter( $module->getName() );
 512                                         continue;
 513                                 }
 514                                 $filteredModules[] = $val;
 515                         }
 516                 }
 517                 return $filteredModules;
 518         }
 519
 520         private function warnModuleTargetFilter( $moduleName ) {
 521                 static $warnings = [];
 522                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 523                         return;
 524                 }
 525                 $warnings[$this->mTarget][$moduleName] = true;
 526                 $this->getResourceLoader()->getLogger()->debug(
 527                         'Module "{module}" not loadable on target "{target}".',
 528                         [
 529                                 'module' => $moduleName,
 530                                 'target' => $this->mTarget,
 531                         ]
 532                 );
 533         }
 534
 535         /**
 536          * Get the list of modules to include on this page
 537          *
 538          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 539          * @param string|null $position Unused
 540          * @param string $param
 541          * @param string $type
 542          * @return array Array of module names
 543          */
 544         public function getModules( $filter = false, $position = null, $param = 'mModules',
 545                 $type = ResourceLoaderModule::TYPE_COMBINED
 546         ) {
 547                 $modules = array_values( array_unique( $this->$param ) );
 548                 return $filter
 549                         ? $this->filterModules( $modules, null, $type )
 550                         : $modules;
 551         }
 552
 553         /**
 554          * Add one or more modules recognized by ResourceLoader. Modules added
 555          * through this function will be loaded by ResourceLoader when the
 556          * page loads.
 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 module JS to include 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          * Add only JS of one or more modules recognized by ResourceLoader. Module
 579          * scripts added through this function will be loaded by ResourceLoader when
 580          * the page loads.
 581          *
 582          * @param string|array $modules Module name (string) or array of module names
 583          */
 584         public function addModuleScripts( $modules ) {
 585                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 586         }
 587
 588         /**
 589          * Get the list of module CSS to include on this page
 590          *
 591          * @param bool $filter
 592          * @param string|null $position Unused
 593          * @return array Array of module names
 594          */
 595         public function getModuleStyles( $filter = false, $position = null ) {
 596                 return $this->getModules( $filter, null, 'mModuleStyles',
 597                         ResourceLoaderModule::TYPE_STYLES
 598                 );
 599         }
 600
 601         /**
 602          * Add only CSS of one or more modules recognized by ResourceLoader.
 603          *
 604          * Module styles added through this function will be added using standard link CSS
 605          * tags, rather than as a combined Javascript and CSS package. Thus, they will
 606          * load when JavaScript is disabled (unless CSS also happens to be disabled).
 607          *
 608          * @param string|array $modules Module name (string) or array of module names
 609          */
 610         public function addModuleStyles( $modules ) {
 611                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 612         }
 613
 614         /**
 615          * @return null|string ResourceLoader target
 616          */
 617         public function getTarget() {
 618                 return $this->mTarget;
 619         }
 620
 621         /**
 622          * Sets ResourceLoader target for load.php links. If null, will be omitted
 623          *
 624          * @param string|null $target
 625          */
 626         public function setTarget( $target ) {
 627                 $this->mTarget = $target;
 628         }
 629
 630         /**
 631          * Get an array of head items
 632          *
 633          * @return array
 634          */
 635         function getHeadItemsArray() {
 636                 return $this->mHeadItems;
 637         }
 638
 639         /**
 640          * Add or replace a head item to the output
 641          *
 642          * Whenever possible, use more specific options like ResourceLoader modules,
 643          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 644          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 645          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 646          * This would be your very LAST fallback.
 647          *
 648          * @param string $name Item name
 649          * @param string $value Raw HTML
 650          */
 651         public function addHeadItem( $name, $value ) {
 652                 $this->mHeadItems[$name] = $value;
 653         }
 654
 655         /**
 656          * Add one or more head items to the output
 657          *
 658          * @since 1.28
 659          * @param string|string[] $values Raw HTML
 660          */
 661         public function addHeadItems( $values ) {
 662                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 663         }
 664
 665         /**
 666          * Check if the header item $name is already set
 667          *
 668          * @param string $name Item name
 669          * @return bool
 670          */
 671         public function hasHeadItem( $name ) {
 672                 return isset( $this->mHeadItems[$name] );
 673         }
 674
 675         /**
 676          * Add a class to the <body> element
 677          *
 678          * @since 1.30
 679          * @param string|string[] $classes One or more classes to add
 680          */
 681         public function addBodyClasses( $classes ) {
 682                 $this->mAdditionalBodyClasses = array_merge( $this->mAdditionalBodyClasses, (array)$classes );
 683         }
 684
 685         /**
 686          * Set whether the output should only contain the body of the article,
 687          * without any skin, sidebar, etc.
 688          * Used e.g. when calling with "action=render".
 689          *
 690          * @param bool $only Whether to output only the body of the article
 691          */
 692         public function setArticleBodyOnly( $only ) {
 693                 $this->mArticleBodyOnly = $only;
 694         }
 695
 696         /**
 697          * Return whether the output will contain only the body of the article
 698          *
 699          * @return bool
 700          */
 701         public function getArticleBodyOnly() {
 702                 return $this->mArticleBodyOnly;
 703         }
 704
 705         /**
 706          * Set an additional output property
 707          * @since 1.21
 708          *
 709          * @param string $name
 710          * @param mixed $value
 711          */
 712         public function setProperty( $name, $value ) {
 713                 $this->mProperties[$name] = $value;
 714         }
 715
 716         /**
 717          * Get an additional output property
 718          * @since 1.21
 719          *
 720          * @param string $name
 721          * @return mixed Property value or null if not found
 722          */
 723         public function getProperty( $name ) {
 724                 if ( isset( $this->mProperties[$name] ) ) {
 725                         return $this->mProperties[$name];
 726                 } else {
 727                         return null;
 728                 }
 729         }
 730
 731         /**
 732          * checkLastModified tells the client to use the client-cached page if
 733          * possible. If successful, the OutputPage is disabled so that
 734          * any future call to OutputPage->output() have no effect.
 735          *
 736          * Side effect: sets mLastModified for Last-Modified header
 737          *
 738          * @param string $timestamp
 739          *
 740          * @return bool True if cache-ok headers was sent.
 741          */
 742         public function checkLastModified( $timestamp ) {
 743                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 744                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 745                         return false;
 746                 }
 747                 $config = $this->getConfig();
 748                 if ( !$config->get( 'CachePages' ) ) {
 749                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 750                         return false;
 751                 }
 752
 753                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 754                 $modifiedTimes = [
 755                         'page' => $timestamp,
 756                         'user' => $this->getUser()->getTouched(),
 757                         'epoch' => $config->get( 'CacheEpoch' )
 758                 ];
 759                 if ( $config->get( 'UseSquid' ) ) {
 760                         // T46570: the core page itself may not change, but resources might
 761                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, time() - $config->get( 'SquidMaxage' ) );
 762                 }
 763                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 764
 765                 $maxModified = max( $modifiedTimes );
 766                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 767
 768                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 769                 if ( $clientHeader === false ) {
 770                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 771                         return false;
 772                 }
 773
 774                 # IE sends sizes after the date like this:
 775                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 776                 # this breaks strtotime().
 777                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 778
 779                 Wikimedia\suppressWarnings(); // E_STRICT system time bitching
 780                 $clientHeaderTime = strtotime( $clientHeader );
 781                 Wikimedia\restoreWarnings();
 782                 if ( !$clientHeaderTime ) {
 783                         wfDebug( __METHOD__
 784                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 785                         return false;
 786                 }
 787                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 788
 789                 # Make debug info
 790                 $info = '';
 791                 foreach ( $modifiedTimes as $name => $value ) {
 792                         if ( $info !== '' ) {
 793                                 $info .= ', ';
 794                         }
 795                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 796                 }
 797
 798                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 799                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 800                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 801                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 802                 if ( $clientHeaderTime < $maxModified ) {
 803                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 804                         return false;
 805                 }
 806
 807                 # Not modified
 808                 # Give a 304 Not Modified response code and disable body output
 809                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 810                 ini_set( 'zlib.output_compression', 0 );
 811                 $this->getRequest()->response()->statusHeader( 304 );
 812                 $this->sendCacheControl();
 813                 $this->disable();
 814
 815                 // Don't output a compressed blob when using ob_gzhandler;
 816                 // it's technically against HTTP spec and seems to confuse
 817                 // Firefox when the response gets split over two packets.
 818                 wfClearOutputBuffers();
 819
 820                 return true;
 821         }
 822
 823         /**
 824          * Override the last modified timestamp
 825          *
 826          * @param string $timestamp New timestamp, in a format readable by
 827          *        wfTimestamp()
 828          */
 829         public function setLastModified( $timestamp ) {
 830                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 831         }
 832
 833         /**
 834          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 835          *
 836          * @param string $policy The literal string to output as the contents of
 837          *   the meta tag.  Will be parsed according to the spec and output in
 838          *   standardized form.
 839          * @return null
 840          */
 841         public function setRobotPolicy( $policy ) {
 842                 $policy = Article::formatRobotPolicy( $policy );
 843
 844                 if ( isset( $policy['index'] ) ) {
 845                         $this->setIndexPolicy( $policy['index'] );
 846                 }
 847                 if ( isset( $policy['follow'] ) ) {
 848                         $this->setFollowPolicy( $policy['follow'] );
 849                 }
 850         }
 851
 852         /**
 853          * Set the index policy for the page, but leave the follow policy un-
 854          * touched.
 855          *
 856          * @param string $policy Either 'index' or 'noindex'.
 857          * @return null
 858          */
 859         public function setIndexPolicy( $policy ) {
 860                 $policy = trim( $policy );
 861                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 862                         $this->mIndexPolicy = $policy;
 863                 }
 864         }
 865
 866         /**
 867          * Set the follow policy for the page, but leave the index policy un-
 868          * touched.
 869          *
 870          * @param string $policy Either 'follow' or 'nofollow'.
 871          * @return null
 872          */
 873         public function setFollowPolicy( $policy ) {
 874                 $policy = trim( $policy );
 875                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 876                         $this->mFollowPolicy = $policy;
 877                 }
 878         }
 879
 880         /**
 881          * Set the new value of the "action text", this will be added to the
 882          * "HTML title", separated from it with " - ".
 883          *
 884          * @param string $text New value of the "action text"
 885          */
 886         public function setPageTitleActionText( $text ) {
 887                 $this->mPageTitleActionText = $text;
 888         }
 889
 890         /**
 891          * Get the value of the "action text"
 892          *
 893          * @return string
 894          */
 895         public function getPageTitleActionText() {
 896                 return $this->mPageTitleActionText;
 897         }
 898
 899         /**
 900          * "HTML title" means the contents of "<title>".
 901          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 902          *
 903          * @param string|Message $name
 904          */
 905         public function setHTMLTitle( $name ) {
 906                 if ( $name instanceof Message ) {
 907                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 908                 } else {
 909                         $this->mHTMLtitle = $name;
 910                 }
 911         }
 912
 913         /**
 914          * Return the "HTML title", i.e. the content of the "<title>" tag.
 915          *
 916          * @return string
 917          */
 918         public function getHTMLTitle() {
 919                 return $this->mHTMLtitle;
 920         }
 921
 922         /**
 923          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 924          *
 925          * @param Title $t
 926          */
 927         public function setRedirectedFrom( $t ) {
 928                 $this->mRedirectedFrom = $t;
 929         }
 930
 931         /**
 932          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 933          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 934          * but not bad tags like \<script\>. This function automatically sets
 935          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 936          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 937          * good tags like \<i\> will be dropped entirely.
 938          *
 939          * @param string|Message $name
 940          */
 941         public function setPageTitle( $name ) {
 942                 if ( $name instanceof Message ) {
 943                         $name = $name->setContext( $this->getContext() )->text();
 944                 }
 945
 946                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 947                 # but leave "<i>foobar</i>" alone
 948                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 949                 $this->mPagetitle = $nameWithTags;
 950
 951                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 952                 $this->setHTMLTitle(
 953                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 954                                 ->inContentLanguage()
 955                 );
 956         }
 957
 958         /**
 959          * Return the "page title", i.e. the content of the \<h1\> tag.
 960          *
 961          * @return string
 962          */
 963         public function getPageTitle() {
 964                 return $this->mPagetitle;
 965         }
 966
 967         /**
 968          * Set the Title object to use
 969          *
 970          * @param Title $t
 971          */
 972         public function setTitle( Title $t ) {
 973                 $this->getContext()->setTitle( $t );
 974         }
 975
 976         /**
 977          * Replace the subtitle with $str
 978          *
 979          * @param string|Message $str New value of the subtitle. String should be safe HTML.
 980          */
 981         public function setSubtitle( $str ) {
 982                 $this->clearSubtitle();
 983                 $this->addSubtitle( $str );
 984         }
 985
 986         /**
 987          * Add $str to the subtitle
 988          *
 989          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
 990          */
 991         public function addSubtitle( $str ) {
 992                 if ( $str instanceof Message ) {
 993                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
 994                 } else {
 995                         $this->mSubtitle[] = $str;
 996                 }
 997         }
 998
 999         /**
1000          * Build message object for a subtitle containing a backlink to a page
1001          *
1002          * @param Title $title Title to link to
1003          * @param array $query Array of additional parameters to include in the link
1004          * @return Message
1005          * @since 1.25
1006          */
1007         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1008                 if ( $title->isRedirect() ) {
1009                         $query['redirect'] = 'no';
1010                 }
1011                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1012                 return wfMessage( 'backlinksubtitle' )
1013                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1014         }
1015
1016         /**
1017          * Add a subtitle containing a backlink to a page
1018          *
1019          * @param Title $title Title to link to
1020          * @param array $query Array of additional parameters to include in the link
1021          */
1022         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1023                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1024         }
1025
1026         /**
1027          * Clear the subtitles
1028          */
1029         public function clearSubtitle() {
1030                 $this->mSubtitle = [];
1031         }
1032
1033         /**
1034          * Get the subtitle
1035          *
1036          * @return string
1037          */
1038         public function getSubtitle() {
1039                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1040         }
1041
1042         /**
1043          * Set the page as printable, i.e. it'll be displayed with all
1044          * print styles included
1045          */
1046         public function setPrintable() {
1047                 $this->mPrintable = true;
1048         }
1049
1050         /**
1051          * Return whether the page is "printable"
1052          *
1053          * @return bool
1054          */
1055         public function isPrintable() {
1056                 return $this->mPrintable;
1057         }
1058
1059         /**
1060          * Disable output completely, i.e. calling output() will have no effect
1061          */
1062         public function disable() {
1063                 $this->mDoNothing = true;
1064         }
1065
1066         /**
1067          * Return whether the output will be completely disabled
1068          *
1069          * @return bool
1070          */
1071         public function isDisabled() {
1072                 return $this->mDoNothing;
1073         }
1074
1075         /**
1076          * Show an "add new section" link?
1077          *
1078          * @return bool
1079          */
1080         public function showNewSectionLink() {
1081                 return $this->mNewSectionLink;
1082         }
1083
1084         /**
1085          * Forcibly hide the new section link?
1086          *
1087          * @return bool
1088          */
1089         public function forceHideNewSectionLink() {
1090                 return $this->mHideNewSectionLink;
1091         }
1092
1093         /**
1094          * Add or remove feed links in the page header
1095          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1096          * for the new version
1097          * @see addFeedLink()
1098          *
1099          * @param bool $show True: add default feeds, false: remove all feeds
1100          */
1101         public function setSyndicated( $show = true ) {
1102                 if ( $show ) {
1103                         $this->setFeedAppendQuery( false );
1104                 } else {
1105                         $this->mFeedLinks = [];
1106                 }
1107         }
1108
1109         /**
1110          * Add default feeds to the page header
1111          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1112          * for the new version
1113          * @see addFeedLink()
1114          *
1115          * @param string $val Query to append to feed links or false to output
1116          *        default links
1117          */
1118         public function setFeedAppendQuery( $val ) {
1119                 $this->mFeedLinks = [];
1120
1121                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1122                         $query = "feed=$type";
1123                         if ( is_string( $val ) ) {
1124                                 $query .= '&' . $val;
1125                         }
1126                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1127                 }
1128         }
1129
1130         /**
1131          * Add a feed link to the page header
1132          *
1133          * @param string $format Feed type, should be a key of $wgFeedClasses
1134          * @param string $href URL
1135          */
1136         public function addFeedLink( $format, $href ) {
1137                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1138                         $this->mFeedLinks[$format] = $href;
1139                 }
1140         }
1141
1142         /**
1143          * Should we output feed links for this page?
1144          * @return bool
1145          */
1146         public function isSyndicated() {
1147                 return count( $this->mFeedLinks ) > 0;
1148         }
1149
1150         /**
1151          * Return URLs for each supported syndication format for this page.
1152          * @return array Associating format keys with URLs
1153          */
1154         public function getSyndicationLinks() {
1155                 return $this->mFeedLinks;
1156         }
1157
1158         /**
1159          * Will currently always return null
1160          *
1161          * @return null
1162          */
1163         public function getFeedAppendQuery() {
1164                 return $this->mFeedLinksAppendQuery;
1165         }
1166
1167         /**
1168          * Set whether the displayed content is related to the source of the
1169          * corresponding article on the wiki
1170          * Setting true will cause the change "article related" toggle to true
1171          *
1172          * @param bool $v
1173          */
1174         public function setArticleFlag( $v ) {
1175                 $this->mIsarticle = $v;
1176                 if ( $v ) {
1177                         $this->mIsArticleRelated = $v;
1178                 }
1179         }
1180
1181         /**
1182          * Return whether the content displayed page is related to the source of
1183          * the corresponding article on the wiki
1184          *
1185          * @return bool
1186          */
1187         public function isArticle() {
1188                 return $this->mIsarticle;
1189         }
1190
1191         /**
1192          * Set whether this page is related an article on the wiki
1193          * Setting false will cause the change of "article flag" toggle to false
1194          *
1195          * @param bool $v
1196          */
1197         public function setArticleRelated( $v ) {
1198                 $this->mIsArticleRelated = $v;
1199                 if ( !$v ) {
1200                         $this->mIsarticle = false;
1201                 }
1202         }
1203
1204         /**
1205          * Return whether this page is related an article on the wiki
1206          *
1207          * @return bool
1208          */
1209         public function isArticleRelated() {
1210                 return $this->mIsArticleRelated;
1211         }
1212
1213         /**
1214          * Add new language links
1215          *
1216          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1217          *                               (e.g. 'fr:Test page')
1218          */
1219         public function addLanguageLinks( array $newLinkArray ) {
1220                 $this->mLanguageLinks += $newLinkArray;
1221         }
1222
1223         /**
1224          * Reset the language links and add new language links
1225          *
1226          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1227          *                               (e.g. 'fr:Test page')
1228          */
1229         public function setLanguageLinks( array $newLinkArray ) {
1230                 $this->mLanguageLinks = $newLinkArray;
1231         }
1232
1233         /**
1234          * Get the list of language links
1235          *
1236          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1237          */
1238         public function getLanguageLinks() {
1239                 return $this->mLanguageLinks;
1240         }
1241
1242         /**
1243          * Add an array of categories, with names in the keys
1244          *
1245          * @param array $categories Mapping category name => sort key
1246          */
1247         public function addCategoryLinks( array $categories ) {
1248                 global $wgContLang;
1249
1250                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1251                         return;
1252                 }
1253
1254                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1255
1256                 # Set all the values to 'normal'.
1257                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1258
1259                 # Mark hidden categories
1260                 foreach ( $res as $row ) {
1261                         if ( isset( $row->pp_value ) ) {
1262                                 $categories[$row->page_title] = 'hidden';
1263                         }
1264                 }
1265
1266                 // Avoid PHP 7.1 warning of passing $this by reference
1267                 $outputPage = $this;
1268                 # Add the remaining categories to the skin
1269                 if ( Hooks::run(
1270                         'OutputPageMakeCategoryLinks',
1271                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1272                 ) {
1273                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1274                         foreach ( $categories as $category => $type ) {
1275                                 // array keys will cast numeric category names to ints, so cast back to string
1276                                 $category = (string)$category;
1277                                 $origcategory = $category;
1278                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1279                                 if ( !$title ) {
1280                                         continue;
1281                                 }
1282                                 $wgContLang->findVariantLink( $category, $title, true );
1283                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1284                                         continue;
1285                                 }
1286                                 $text = $wgContLang->convertHtml( $title->getText() );
1287                                 $this->mCategories[$type][] = $title->getText();
1288                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1289                         }
1290                 }
1291         }
1292
1293         /**
1294          * @param array $categories
1295          * @return bool|ResultWrapper
1296          */
1297         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1298                 # Add the links to a LinkBatch
1299                 $arr = [ NS_CATEGORY => $categories ];
1300                 $lb = new LinkBatch;
1301                 $lb->setArray( $arr );
1302
1303                 # Fetch existence plus the hiddencat property
1304                 $dbr = wfGetDB( DB_REPLICA );
1305                 $fields = array_merge(
1306                         LinkCache::getSelectFields(),
1307                         [ 'page_namespace', 'page_title', 'pp_value' ]
1308                 );
1309
1310                 $res = $dbr->select( [ 'page', 'page_props' ],
1311                         $fields,
1312                         $lb->constructSet( 'page', $dbr ),
1313                         __METHOD__,
1314                         [],
1315                         [ 'page_props' => [ 'LEFT JOIN', [
1316                                 'pp_propname' => 'hiddencat',
1317                                 'pp_page = page_id'
1318                         ] ] ]
1319                 );
1320
1321                 # Add the results to the link cache
1322                 $lb->addResultToCache( LinkCache::singleton(), $res );
1323
1324                 return $res;
1325         }
1326
1327         /**
1328          * Reset the category links (but not the category list) and add $categories
1329          *
1330          * @param array $categories Mapping category name => sort key
1331          */
1332         public function setCategoryLinks( array $categories ) {
1333                 $this->mCategoryLinks = [];
1334                 $this->addCategoryLinks( $categories );
1335         }
1336
1337         /**
1338          * Get the list of category links, in a 2-D array with the following format:
1339          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1340          * hidden categories) and $link a HTML fragment with a link to the category
1341          * page
1342          *
1343          * @return array
1344          */
1345         public function getCategoryLinks() {
1346                 return $this->mCategoryLinks;
1347         }
1348
1349         /**
1350          * Get the list of category names this page belongs to.
1351          *
1352          * @param string $type The type of categories which should be returned. Possible values:
1353          *  * all: all categories of all types
1354          *  * hidden: only the hidden categories
1355          *  * normal: all categories, except hidden categories
1356          * @return array Array of strings
1357          */
1358         public function getCategories( $type = 'all' ) {
1359                 if ( $type === 'all' ) {
1360                         $allCategories = [];
1361                         foreach ( $this->mCategories as $categories ) {
1362                                 $allCategories = array_merge( $allCategories, $categories );
1363                         }
1364                         return $allCategories;
1365                 }
1366                 if ( !isset( $this->mCategories[$type] ) ) {
1367                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1368                 }
1369                 return $this->mCategories[$type];
1370         }
1371
1372         /**
1373          * Add an array of indicators, with their identifiers as array
1374          * keys and HTML contents as values.
1375          *
1376          * In case of duplicate keys, existing values are overwritten.
1377          *
1378          * @param array $indicators
1379          * @since 1.25
1380          */
1381         public function setIndicators( array $indicators ) {
1382                 $this->mIndicators = $indicators + $this->mIndicators;
1383                 // Keep ordered by key
1384                 ksort( $this->mIndicators );
1385         }
1386
1387         /**
1388          * Get the indicators associated with this page.
1389          *
1390          * The array will be internally ordered by item keys.
1391          *
1392          * @return array Keys: identifiers, values: HTML contents
1393          * @since 1.25
1394          */
1395         public function getIndicators() {
1396                 return $this->mIndicators;
1397         }
1398
1399         /**
1400          * Adds help link with an icon via page indicators.
1401          * Link target can be overridden by a local message containing a wikilink:
1402          * the message key is: lowercase action or special page name + '-helppage'.
1403          * @param string $to Target MediaWiki.org page title or encoded URL.
1404          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1405          * @since 1.25
1406          */
1407         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1408                 $this->addModuleStyles( 'mediawiki.helplink' );
1409                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1410
1411                 if ( $overrideBaseUrl ) {
1412                         $helpUrl = $to;
1413                 } else {
1414                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1415                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1416                 }
1417
1418                 $link = Html::rawElement(
1419                         'a',
1420                         [
1421                                 'href' => $helpUrl,
1422                                 'target' => '_blank',
1423                                 'class' => 'mw-helplink',
1424                         ],
1425                         $text
1426                 );
1427
1428                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1429         }
1430
1431         /**
1432          * Do not allow scripts which can be modified by wiki users to load on this page;
1433          * only allow scripts bundled with, or generated by, the software.
1434          * Site-wide styles are controlled by a config setting, since they can be
1435          * used to create a custom skin/theme, but not user-specific ones.
1436          *
1437          * @todo this should be given a more accurate name
1438          */
1439         public function disallowUserJs() {
1440                 $this->reduceAllowedModules(
1441                         ResourceLoaderModule::TYPE_SCRIPTS,
1442                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1443                 );
1444
1445                 // Site-wide styles are controlled by a config setting, see T73621
1446                 // for background on why. User styles are never allowed.
1447                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1448                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1449                 } else {
1450                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1451                 }
1452                 $this->reduceAllowedModules(
1453                         ResourceLoaderModule::TYPE_STYLES,
1454                         $styleOrigin
1455                 );
1456         }
1457
1458         /**
1459          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1460          * @see ResourceLoaderModule::$origin
1461          * @param string $type ResourceLoaderModule TYPE_ constant
1462          * @return int ResourceLoaderModule ORIGIN_ class constant
1463          */
1464         public function getAllowedModules( $type ) {
1465                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1466                         return min( array_values( $this->mAllowedModules ) );
1467                 } else {
1468                         return isset( $this->mAllowedModules[$type] )
1469                                 ? $this->mAllowedModules[$type]
1470                                 : ResourceLoaderModule::ORIGIN_ALL;
1471                 }
1472         }
1473
1474         /**
1475          * Limit the highest level of CSS/JS untrustworthiness allowed.
1476          *
1477          * If passed the same or a higher level than the current level of untrustworthiness set, the
1478          * level will remain unchanged.
1479          *
1480          * @param string $type
1481          * @param int $level ResourceLoaderModule class constant
1482          */
1483         public function reduceAllowedModules( $type, $level ) {
1484                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1485         }
1486
1487         /**
1488          * Prepend $text to the body HTML
1489          *
1490          * @param string $text HTML
1491          */
1492         public function prependHTML( $text ) {
1493                 $this->mBodytext = $text . $this->mBodytext;
1494         }
1495
1496         /**
1497          * Append $text to the body HTML
1498          *
1499          * @param string $text HTML
1500          */
1501         public function addHTML( $text ) {
1502                 $this->mBodytext .= $text;
1503         }
1504
1505         /**
1506          * Shortcut for adding an Html::element via addHTML.
1507          *
1508          * @since 1.19
1509          *
1510          * @param string $element
1511          * @param array $attribs
1512          * @param string $contents
1513          */
1514         public function addElement( $element, array $attribs = [], $contents = '' ) {
1515                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1516         }
1517
1518         /**
1519          * Clear the body HTML
1520          */
1521         public function clearHTML() {
1522                 $this->mBodytext = '';
1523         }
1524
1525         /**
1526          * Get the body HTML
1527          *
1528          * @return string HTML
1529          */
1530         public function getHTML() {
1531                 return $this->mBodytext;
1532         }
1533
1534         /**
1535          * Get/set the ParserOptions object to use for wikitext parsing
1536          *
1537          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1538          *   current ParserOption object. This parameter is deprecated since 1.31.
1539          * @return ParserOptions
1540          */
1541         public function parserOptions( $options = null ) {
1542                 if ( $options !== null ) {
1543                         wfDeprecated( __METHOD__ . ' with non-null $options', '1.31' );
1544                 }
1545
1546                 if ( $options !== null && !empty( $options->isBogus ) ) {
1547                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1548                         // been changed somehow, and keep it if so.
1549                         $anonPO = ParserOptions::newFromAnon();
1550                         $anonPO->setEditSection( false );
1551                         $anonPO->setAllowUnsafeRawHtml( false );
1552                         if ( !$options->matches( $anonPO ) ) {
1553                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1554                                 $options->isBogus = false;
1555                         }
1556                 }
1557
1558                 if ( !$this->mParserOptions ) {
1559                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1560                                 // $wgUser isn't unstubbable yet, so don't try to get a
1561                                 // ParserOptions for it. And don't cache this ParserOptions
1562                                 // either.
1563                                 $po = ParserOptions::newFromAnon();
1564                                 $po->setEditSection( false );
1565                                 $po->setAllowUnsafeRawHtml( false );
1566                                 $po->isBogus = true;
1567                                 if ( $options !== null ) {
1568                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1569                                 }
1570                                 return $po;
1571                         }
1572
1573                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1574                         $this->mParserOptions->setEditSection( false );
1575                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1576                 }
1577
1578                 if ( $options !== null && !empty( $options->isBogus ) ) {
1579                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1580                         // thing.
1581                         return wfSetVar( $this->mParserOptions, null, true );
1582                 } else {
1583                         return wfSetVar( $this->mParserOptions, $options );
1584                 }
1585         }
1586
1587         /**
1588          * Set the revision ID which will be seen by the wiki text parser
1589          * for things such as embedded {{REVISIONID}} variable use.
1590          *
1591          * @param int|null $revid An positive integer, or null
1592          * @return mixed Previous value
1593          */
1594         public function setRevisionId( $revid ) {
1595                 $val = is_null( $revid ) ? null : intval( $revid );
1596                 return wfSetVar( $this->mRevisionId, $val );
1597         }
1598
1599         /**
1600          * Get the displayed revision ID
1601          *
1602          * @return int
1603          */
1604         public function getRevisionId() {
1605                 return $this->mRevisionId;
1606         }
1607
1608         /**
1609          * Set the timestamp of the revision which will be displayed. This is used
1610          * to avoid a extra DB call in Skin::lastModified().
1611          *
1612          * @param string|null $timestamp
1613          * @return mixed Previous value
1614          */
1615         public function setRevisionTimestamp( $timestamp ) {
1616                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1617         }
1618
1619         /**
1620          * Get the timestamp of displayed revision.
1621          * This will be null if not filled by setRevisionTimestamp().
1622          *
1623          * @return string|null
1624          */
1625         public function getRevisionTimestamp() {
1626                 return $this->mRevisionTimestamp;
1627         }
1628
1629         /**
1630          * Set the displayed file version
1631          *
1632          * @param File|bool $file
1633          * @return mixed Previous value
1634          */
1635         public function setFileVersion( $file ) {
1636                 $val = null;
1637                 if ( $file instanceof File && $file->exists() ) {
1638                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1639                 }
1640                 return wfSetVar( $this->mFileVersion, $val, true );
1641         }
1642
1643         /**
1644          * Get the displayed file version
1645          *
1646          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1647          */
1648         public function getFileVersion() {
1649                 return $this->mFileVersion;
1650         }
1651
1652         /**
1653          * Get the templates used on this page
1654          *
1655          * @return array (namespace => dbKey => revId)
1656          * @since 1.18
1657          */
1658         public function getTemplateIds() {
1659                 return $this->mTemplateIds;
1660         }
1661
1662         /**
1663          * Get the files used on this page
1664          *
1665          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1666          * @since 1.18
1667          */
1668         public function getFileSearchOptions() {
1669                 return $this->mImageTimeKeys;
1670         }
1671
1672         /**
1673          * Convert wikitext to HTML and add it to the buffer
1674          * Default assumes that the current page title will be used.
1675          *
1676          * @param string $text
1677          * @param bool $linestart Is this the start of a line?
1678          * @param bool $interface Is this text in the user interface language?
1679          * @throws MWException
1680          */
1681         public function addWikiText( $text, $linestart = true, $interface = true ) {
1682                 $title = $this->getTitle(); // Work around E_STRICT
1683                 if ( !$title ) {
1684                         throw new MWException( 'Title is null' );
1685                 }
1686                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1687         }
1688
1689         /**
1690          * Add wikitext with a custom Title object
1691          *
1692          * @param string $text Wikitext
1693          * @param Title &$title
1694          * @param bool $linestart Is this the start of a line?
1695          */
1696         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1697                 $this->addWikiTextTitle( $text, $title, $linestart );
1698         }
1699
1700         /**
1701          * Add wikitext with a custom Title object and tidy enabled.
1702          *
1703          * @param string $text Wikitext
1704          * @param Title &$title
1705          * @param bool $linestart Is this the start of a line?
1706          */
1707         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1708                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1709         }
1710
1711         /**
1712          * Add wikitext with tidy enabled
1713          *
1714          * @param string $text Wikitext
1715          * @param bool $linestart Is this the start of a line?
1716          */
1717         public function addWikiTextTidy( $text, $linestart = true ) {
1718                 $title = $this->getTitle();
1719                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1720         }
1721
1722         /**
1723          * Add wikitext with a custom Title object
1724          *
1725          * @param string $text Wikitext
1726          * @param Title $title
1727          * @param bool $linestart Is this the start of a line?
1728          * @param bool $tidy Whether to use tidy
1729          * @param bool $interface Whether it is an interface message
1730          *   (for example disables conversion)
1731          */
1732         public function addWikiTextTitle( $text, Title $title, $linestart,
1733                 $tidy = false, $interface = false
1734         ) {
1735                 global $wgParser;
1736
1737                 $popts = $this->parserOptions();
1738                 $oldTidy = $popts->setTidy( $tidy );
1739                 $popts->setInterfaceMessage( (bool)$interface );
1740
1741                 $parserOutput = $wgParser->getFreshParser()->parse(
1742                         $text, $title, $popts,
1743                         $linestart, true, $this->mRevisionId
1744                 );
1745
1746                 $popts->setTidy( $oldTidy );
1747
1748                 $this->addParserOutput( $parserOutput, [
1749                         'enableSectionEditLinks' => false,
1750                 ] );
1751         }
1752
1753         /**
1754          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1755          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1756          * and so on.
1757          *
1758          * @since 1.24
1759          * @param ParserOutput $parserOutput
1760          */
1761         public function addParserOutputMetadata( $parserOutput ) {
1762                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1763                 $this->addCategoryLinks( $parserOutput->getCategories() );
1764                 $this->setIndicators( $parserOutput->getIndicators() );
1765                 $this->mNewSectionLink = $parserOutput->getNewSection();
1766                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1767
1768                 if ( !$parserOutput->isCacheable() ) {
1769                         $this->enableClientCache( false );
1770                 }
1771                 $this->mNoGallery = $parserOutput->getNoGallery();
1772                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1773                 $this->addModules( $parserOutput->getModules() );
1774                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1775                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1776                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1777                 $this->mPreventClickjacking = $this->mPreventClickjacking
1778                         || $parserOutput->preventClickjacking();
1779
1780                 // Template versioning...
1781                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1782                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1783                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1784                         } else {
1785                                 $this->mTemplateIds[$ns] = $dbks;
1786                         }
1787                 }
1788                 // File versioning...
1789                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1790                         $this->mImageTimeKeys[$dbk] = $data;
1791                 }
1792
1793                 // Hooks registered in the object
1794                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1795                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1796                         list( $hookName, $data ) = $hookInfo;
1797                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1798                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1799                         }
1800                 }
1801
1802                 // Enable OOUI if requested via ParserOutput
1803                 if ( $parserOutput->getEnableOOUI() ) {
1804                         $this->enableOOUI();
1805                 }
1806
1807                 // Include parser limit report
1808                 if ( !$this->limitReportJSData ) {
1809                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1810                 }
1811
1812                 // Link flags are ignored for now, but may in the future be
1813                 // used to mark individual language links.
1814                 $linkFlags = [];
1815                 // Avoid PHP 7.1 warning of passing $this by reference
1816                 $outputPage = $this;
1817                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1818                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1819
1820                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
1821                 // so that extensions may modify ParserOutput to toggle TOC.
1822                 // This cannot be moved to addParserOutputText because that is not
1823                 // called by EditPage for Preview.
1824                 if ( $parserOutput->getTOCEnabled() && $parserOutput->getTOCHTML() ) {
1825                         $this->mEnableTOC = true;
1826                 }
1827         }
1828
1829         /**
1830          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1831          * ParserOutput object, without any other metadata.
1832          *
1833          * @since 1.24
1834          * @param ParserOutput $parserOutput
1835          * @param array $poOptions Options to ParserOutput::getText()
1836          */
1837         public function addParserOutputContent( $parserOutput, $poOptions = [] ) {
1838                 $this->addParserOutputText( $parserOutput, $poOptions );
1839
1840                 $this->addModules( $parserOutput->getModules() );
1841                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1842                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1843
1844                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1845         }
1846
1847         /**
1848          * Add the HTML associated with a ParserOutput object, without any metadata.
1849          *
1850          * @since 1.24
1851          * @param ParserOutput $parserOutput
1852          * @param array $poOptions Options to ParserOutput::getText()
1853          */
1854         public function addParserOutputText( $parserOutput, $poOptions = [] ) {
1855                 $text = $parserOutput->getText( $poOptions );
1856                 // Avoid PHP 7.1 warning of passing $this by reference
1857                 $outputPage = $this;
1858                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1859                 $this->addHTML( $text );
1860         }
1861
1862         /**
1863          * Add everything from a ParserOutput object.
1864          *
1865          * @param ParserOutput $parserOutput
1866          * @param array $poOptions Options to ParserOutput::getText()
1867          */
1868         function addParserOutput( $parserOutput, $poOptions = [] ) {
1869                 $this->addParserOutputMetadata( $parserOutput );
1870
1871                 // Touch section edit links only if not previously disabled
1872                 if ( $parserOutput->getEditSectionTokens() ) {
1873                         $parserOutput->setEditSectionTokens( $this->mEnableSectionEditLinks );
1874                 }
1875                 if ( !$this->mEnableSectionEditLinks
1876                         && !array_key_exists( 'enableSectionEditLinks', $poOptions )
1877                 ) {
1878                         $poOptions['enableSectionEditLinks'] = false;
1879                 }
1880
1881                 $this->addParserOutputText( $parserOutput, $poOptions );
1882         }
1883
1884         /**
1885          * Add the output of a QuickTemplate to the output buffer
1886          *
1887          * @param QuickTemplate &$template
1888          */
1889         public function addTemplate( &$template ) {
1890                 $this->addHTML( $template->getHTML() );
1891         }
1892
1893         /**
1894          * Parse wikitext and return the HTML.
1895          *
1896          * @param string $text
1897          * @param bool $linestart Is this the start of a line?
1898          * @param bool $interface Use interface language ($wgLang instead of
1899          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1900          *   This also disables LanguageConverter.
1901          * @param Language $language Target language object, will override $interface
1902          * @throws MWException
1903          * @return string HTML
1904          */
1905         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1906                 global $wgParser;
1907
1908                 if ( is_null( $this->getTitle() ) ) {
1909                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1910                 }
1911
1912                 $popts = $this->parserOptions();
1913                 if ( $interface ) {
1914                         $popts->setInterfaceMessage( true );
1915                 }
1916                 if ( $language !== null ) {
1917                         $oldLang = $popts->setTargetLanguage( $language );
1918                 }
1919
1920                 $parserOutput = $wgParser->getFreshParser()->parse(
1921                         $text, $this->getTitle(), $popts,
1922                         $linestart, true, $this->mRevisionId
1923                 );
1924
1925                 if ( $interface ) {
1926                         $popts->setInterfaceMessage( false );
1927                 }
1928                 if ( $language !== null ) {
1929                         $popts->setTargetLanguage( $oldLang );
1930                 }
1931
1932                 return $parserOutput->getText( [
1933                         'enableSectionEditLinks' => false,
1934                 ] );
1935         }
1936
1937         /**
1938          * Parse wikitext, strip paragraphs, and return the HTML.
1939          *
1940          * @param string $text
1941          * @param bool $linestart Is this the start of a line?
1942          * @param bool $interface Use interface language ($wgLang instead of
1943          *   $wgContLang) while parsing language sensitive magic
1944          *   words like GRAMMAR and PLURAL
1945          * @return string HTML
1946          */
1947         public function parseInline( $text, $linestart = true, $interface = false ) {
1948                 $parsed = $this->parse( $text, $linestart, $interface );
1949                 return Parser::stripOuterParagraph( $parsed );
1950         }
1951
1952         /**
1953          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1954          *
1955          * @param int $maxage Maximum cache time on the CDN, in seconds.
1956          */
1957         public function setCdnMaxage( $maxage ) {
1958                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1959         }
1960
1961         /**
1962          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1963          *
1964          * @param int $maxage Maximum cache time on the CDN, in seconds
1965          * @since 1.27
1966          */
1967         public function lowerCdnMaxage( $maxage ) {
1968                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1969                 $this->setCdnMaxage( $this->mCdnMaxage );
1970         }
1971
1972         /**
1973          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
1974          *
1975          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
1976          * the TTL is higher the older the $mtime timestamp is. Essentially, the
1977          * TTL is 90% of the age of the object, subject to the min and max.
1978          *
1979          * @param string|int|float|bool|null $mtime Last-Modified timestamp
1980          * @param int $minTTL Mimimum TTL in seconds [default: 1 minute]
1981          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
1982          * @return int TTL in seconds
1983          * @since 1.28
1984          */
1985         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
1986                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
1987                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
1988
1989                 if ( $mtime === null || $mtime === false ) {
1990                         return $minTTL; // entity does not exist
1991                 }
1992
1993                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
1994                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
1995                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
1996
1997                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
1998
1999                 return $adaptiveTTL;
2000         }
2001
2002         /**
2003          * Use enableClientCache(false) to force it to send nocache headers
2004          *
2005          * @param bool $state
2006          *
2007          * @return bool
2008          */
2009         public function enableClientCache( $state ) {
2010                 return wfSetVar( $this->mEnableClientCache, $state );
2011         }
2012
2013         /**
2014          * Get the list of cookies that will influence on the cache
2015          *
2016          * @return array
2017          */
2018         function getCacheVaryCookies() {
2019                 static $cookies;
2020                 if ( $cookies === null ) {
2021                         $config = $this->getConfig();
2022                         $cookies = array_merge(
2023                                 SessionManager::singleton()->getVaryCookies(),
2024                                 [
2025                                         'forceHTTPS',
2026                                 ],
2027                                 $config->get( 'CacheVaryCookies' )
2028                         );
2029                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2030                 }
2031                 return $cookies;
2032         }
2033
2034         /**
2035          * Check if the request has a cache-varying cookie header
2036          * If it does, it's very important that we don't allow public caching
2037          *
2038          * @return bool
2039          */
2040         function haveCacheVaryCookies() {
2041                 $request = $this->getRequest();
2042                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2043                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2044                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2045                                 return true;
2046                         }
2047                 }
2048                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2049                 return false;
2050         }
2051
2052         /**
2053          * Add an HTTP header that will influence on the cache
2054          *
2055          * @param string $header Header name
2056          * @param string[]|null $option Options for the Key header. See
2057          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2058          * for the list of valid options.
2059          */
2060         public function addVaryHeader( $header, array $option = null ) {
2061                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2062                         $this->mVaryHeader[$header] = [];
2063                 }
2064                 if ( !is_array( $option ) ) {
2065                         $option = [];
2066                 }
2067                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2068         }
2069
2070         /**
2071          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2072          * such as Accept-Encoding or Cookie
2073          *
2074          * @return string
2075          */
2076         public function getVaryHeader() {
2077                 // If we vary on cookies, let's make sure it's always included here too.
2078                 if ( $this->getCacheVaryCookies() ) {
2079                         $this->addVaryHeader( 'Cookie' );
2080                 }
2081
2082                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2083                         $this->addVaryHeader( $header, $options );
2084                 }
2085                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2086         }
2087
2088         /**
2089          * Add an HTTP Link: header
2090          *
2091          * @param string $header Header value
2092          */
2093         public function addLinkHeader( $header ) {
2094                 $this->mLinkHeader[] = $header;
2095         }
2096
2097         /**
2098          * Return a Link: header. Based on the values of $mLinkHeader.
2099          *
2100          * @return string
2101          */
2102         public function getLinkHeader() {
2103                 if ( !$this->mLinkHeader ) {
2104                         return false;
2105                 }
2106
2107                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2108         }
2109
2110         /**
2111          * Get a complete Key header
2112          *
2113          * @return string
2114          */
2115         public function getKeyHeader() {
2116                 $cvCookies = $this->getCacheVaryCookies();
2117
2118                 $cookiesOption = [];
2119                 foreach ( $cvCookies as $cookieName ) {
2120                         $cookiesOption[] = 'param=' . $cookieName;
2121                 }
2122                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2123
2124                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2125                         $this->addVaryHeader( $header, $options );
2126                 }
2127
2128                 $headers = [];
2129                 foreach ( $this->mVaryHeader as $header => $option ) {
2130                         $newheader = $header;
2131                         if ( is_array( $option ) && count( $option ) > 0 ) {
2132                                 $newheader .= ';' . implode( ';', $option );
2133                         }
2134                         $headers[] = $newheader;
2135                 }
2136                 $key = 'Key: ' . implode( ',', $headers );
2137
2138                 return $key;
2139         }
2140
2141         /**
2142          * T23672: Add Accept-Language to Vary and Key headers
2143          * if there's no 'variant' parameter existed in GET.
2144          *
2145          * For example:
2146          *   /w/index.php?title=Main_page should always be served; but
2147          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2148          */
2149         function addAcceptLanguage() {
2150                 $title = $this->getTitle();
2151                 if ( !$title instanceof Title ) {
2152                         return;
2153                 }
2154
2155                 $lang = $title->getPageLanguage();
2156                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2157                         $variants = $lang->getVariants();
2158                         $aloption = [];
2159                         foreach ( $variants as $variant ) {
2160                                 if ( $variant === $lang->getCode() ) {
2161                                         continue;
2162                                 } else {
2163                                         $aloption[] = 'substr=' . $variant;
2164
2165                                         // IE and some other browsers use BCP 47 standards in
2166                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2167                                         // We should handle these too.
2168                                         $variantBCP47 = LanguageCode::bcp47( $variant );
2169                                         if ( $variantBCP47 !== $variant ) {
2170                                                 $aloption[] = 'substr=' . $variantBCP47;
2171                                         }
2172                                 }
2173                         }
2174                         $this->addVaryHeader( 'Accept-Language', $aloption );
2175                 }
2176         }
2177
2178         /**
2179          * Set a flag which will cause an X-Frame-Options header appropriate for
2180          * edit pages to be sent. The header value is controlled by
2181          * $wgEditPageFrameOptions.
2182          *
2183          * This is the default for special pages. If you display a CSRF-protected
2184          * form on an ordinary view page, then you need to call this function.
2185          *
2186          * @param bool $enable
2187          */
2188         public function preventClickjacking( $enable = true ) {
2189                 $this->mPreventClickjacking = $enable;
2190         }
2191
2192         /**
2193          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2194          * This can be called from pages which do not contain any CSRF-protected
2195          * HTML form.
2196          */
2197         public function allowClickjacking() {
2198                 $this->mPreventClickjacking = false;
2199         }
2200
2201         /**
2202          * Get the prevent-clickjacking flag
2203          *
2204          * @since 1.24
2205          * @return bool
2206          */
2207         public function getPreventClickjacking() {
2208                 return $this->mPreventClickjacking;
2209         }
2210
2211         /**
2212          * Get the X-Frame-Options header value (without the name part), or false
2213          * if there isn't one. This is used by Skin to determine whether to enable
2214          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2215          *
2216          * @return string|false
2217          */
2218         public function getFrameOptions() {
2219                 $config = $this->getConfig();
2220                 if ( $config->get( 'BreakFrames' ) ) {
2221                         return 'DENY';
2222                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2223                         return $config->get( 'EditPageFrameOptions' );
2224                 }
2225                 return false;
2226         }
2227
2228         /**
2229          * Send cache control HTTP headers
2230          */
2231         public function sendCacheControl() {
2232                 $response = $this->getRequest()->response();
2233                 $config = $this->getConfig();
2234
2235                 $this->addVaryHeader( 'Cookie' );
2236                 $this->addAcceptLanguage();
2237
2238                 # don't serve compressed data to clients who can't handle it
2239                 # maintain different caches for logged-in users and non-logged in ones
2240                 $response->header( $this->getVaryHeader() );
2241
2242                 if ( $config->get( 'UseKeyHeader' ) ) {
2243                         $response->header( $this->getKeyHeader() );
2244                 }
2245
2246                 if ( $this->mEnableClientCache ) {
2247                         if (
2248                                 $config->get( 'UseSquid' ) &&
2249                                 !$response->hasCookies() &&
2250                                 !SessionManager::getGlobalSession()->isPersistent() &&
2251                                 !$this->isPrintable() &&
2252                                 $this->mCdnMaxage != 0 &&
2253                                 !$this->haveCacheVaryCookies()
2254                         ) {
2255                                 if ( $config->get( 'UseESI' ) ) {
2256                                         # We'll purge the proxy cache explicitly, but require end user agents
2257                                         # to revalidate against the proxy on each visit.
2258                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2259                                         wfDebug( __METHOD__ .
2260                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2261                                         # start with a shorter timeout for initial testing
2262                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2263                                         $response->header(
2264                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2265                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2266                                         );
2267                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2268                                 } else {
2269                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2270                                         # to revalidate against the proxy on each visit.
2271                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2272                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2273                                         wfDebug( __METHOD__ .
2274                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2275                                         # start with a shorter timeout for initial testing
2276                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2277                                         $response->header( "Cache-Control: " .
2278                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2279                                 }
2280                         } else {
2281                                 # We do want clients to cache if they can, but they *must* check for updates
2282                                 # on revisiting the page.
2283                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2284                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2285                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2286                         }
2287                         if ( $this->mLastModified ) {
2288                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2289                         }
2290                 } else {
2291                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2292
2293                         # In general, the absence of a last modified header should be enough to prevent
2294                         # the client from using its cache. We send a few other things just to make sure.
2295                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2296                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2297                         $response->header( 'Pragma: no-cache' );
2298                 }
2299         }
2300
2301         /**
2302          * Finally, all the text has been munged and accumulated into
2303          * the object, let's actually output it:
2304          *
2305          * @param bool $return Set to true to get the result as a string rather than sending it
2306          * @return string|null
2307          * @throws Exception
2308          * @throws FatalError
2309          * @throws MWException
2310          */
2311         public function output( $return = false ) {
2312                 global $wgContLang;
2313
2314                 if ( $this->mDoNothing ) {
2315                         return $return ? '' : null;
2316                 }
2317
2318                 $response = $this->getRequest()->response();
2319                 $config = $this->getConfig();
2320
2321                 if ( $this->mRedirect != '' ) {
2322                         # Standards require redirect URLs to be absolute
2323                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2324
2325                         $redirect = $this->mRedirect;
2326                         $code = $this->mRedirectCode;
2327
2328                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2329                                 if ( $code == '301' || $code == '303' ) {
2330                                         if ( !$config->get( 'DebugRedirects' ) ) {
2331                                                 $response->statusHeader( $code );
2332                                         }
2333                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2334                                 }
2335                                 if ( $config->get( 'VaryOnXFP' ) ) {
2336                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2337                                 }
2338                                 $this->sendCacheControl();
2339
2340                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2341                                 if ( $config->get( 'DebugRedirects' ) ) {
2342                                         $url = htmlspecialchars( $redirect );
2343                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2344                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2345                                         print "</body>\n</html>\n";
2346                                 } else {
2347                                         $response->header( 'Location: ' . $redirect );
2348                                 }
2349                         }
2350
2351                         return $return ? '' : null;
2352                 } elseif ( $this->mStatusCode ) {
2353                         $response->statusHeader( $this->mStatusCode );
2354                 }
2355
2356                 # Buffer output; final headers may depend on later processing
2357                 ob_start();
2358
2359                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2360                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2361
2362                 // Avoid Internet Explorer "compatibility view" in IE 8-10, so that
2363                 // jQuery etc. can work correctly.
2364                 $response->header( 'X-UA-Compatible: IE=Edge' );
2365
2366                 if ( !$this->mArticleBodyOnly ) {
2367                         $sk = $this->getSkin();
2368
2369                         if ( $sk->shouldPreloadLogo() ) {
2370                                 $this->addLogoPreloadLinkHeaders();
2371                         }
2372                 }
2373
2374                 $linkHeader = $this->getLinkHeader();
2375                 if ( $linkHeader ) {
2376                         $response->header( $linkHeader );
2377                 }
2378
2379                 // Prevent framing, if requested
2380                 $frameOptions = $this->getFrameOptions();
2381                 if ( $frameOptions ) {
2382                         $response->header( "X-Frame-Options: $frameOptions" );
2383                 }
2384
2385                 if ( $this->mArticleBodyOnly ) {
2386                         echo $this->mBodytext;
2387                 } else {
2388                         // Enable safe mode if requested
2389                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2390                                 $this->disallowUserJs();
2391                         }
2392
2393                         $sk = $this->getSkin();
2394                         foreach ( $sk->getDefaultModules() as $group ) {
2395                                 $this->addModules( $group );
2396                         }
2397
2398                         MWDebug::addModules( $this );
2399
2400                         // Avoid PHP 7.1 warning of passing $this by reference
2401                         $outputPage = $this;
2402                         // Hook that allows last minute changes to the output page, e.g.
2403                         // adding of CSS or Javascript by extensions.
2404                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2405
2406                         try {
2407                                 $sk->outputPage();
2408                         } catch ( Exception $e ) {
2409                                 ob_end_clean(); // bug T129657
2410                                 throw $e;
2411                         }
2412                 }
2413
2414                 try {
2415                         // This hook allows last minute changes to final overall output by modifying output buffer
2416                         Hooks::runWithoutAbort( 'AfterFinalPageOutput', [ $this ] );
2417                 } catch ( Exception $e ) {
2418                         ob_end_clean(); // bug T129657
2419                         throw $e;
2420                 }
2421
2422                 $this->sendCacheControl();
2423
2424                 if ( $return ) {
2425                         return ob_get_clean();
2426                 } else {
2427                         ob_end_flush();
2428                         return null;
2429                 }
2430         }
2431
2432         /**
2433          * Prepare this object to display an error page; disable caching and
2434          * indexing, clear the current text and redirect, set the page's title
2435          * and optionally an custom HTML title (content of the "<title>" tag).
2436          *
2437          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2438          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2439          *                   optional, if not passed the "<title>" attribute will be
2440          *                   based on $pageTitle
2441          */
2442         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2443                 $this->setPageTitle( $pageTitle );
2444                 if ( $htmlTitle !== false ) {
2445                         $this->setHTMLTitle( $htmlTitle );
2446                 }
2447                 $this->setRobotPolicy( 'noindex,nofollow' );
2448                 $this->setArticleRelated( false );
2449                 $this->enableClientCache( false );
2450                 $this->mRedirect = '';
2451                 $this->clearSubtitle();
2452                 $this->clearHTML();
2453         }
2454
2455         /**
2456          * Output a standard error page
2457          *
2458          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2459          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2460          * showErrorPage( 'titlemsg', $messageObject );
2461          * showErrorPage( $titleMessageObject, $messageObject );
2462          *
2463          * @param string|Message $title Message key (string) for page title, or a Message object
2464          * @param string|Message $msg Message key (string) for page text, or a Message object
2465          * @param array $params Message parameters; ignored if $msg is a Message object
2466          */
2467         public function showErrorPage( $title, $msg, $params = [] ) {
2468                 if ( !$title instanceof Message ) {
2469                         $title = $this->msg( $title );
2470                 }
2471
2472                 $this->prepareErrorPage( $title );
2473
2474                 if ( $msg instanceof Message ) {
2475                         if ( $params !== [] ) {
2476                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2477                                         . 'is discarded when the $msg argument is a Message object instead of '
2478                                         . 'a string.', E_USER_NOTICE );
2479                         }
2480                         $this->addHTML( $msg->parseAsBlock() );
2481                 } else {
2482                         $this->addWikiMsgArray( $msg, $params );
2483                 }
2484
2485                 $this->returnToMain();
2486         }
2487
2488         /**
2489          * Output a standard permission error page
2490          *
2491          * @param array $errors Error message keys or [key, param...] arrays
2492          * @param string $action Action that was denied or null if unknown
2493          */
2494         public function showPermissionsErrorPage( array $errors, $action = null ) {
2495                 foreach ( $errors as $key => $error ) {
2496                         $errors[$key] = (array)$error;
2497                 }
2498
2499                 // For some action (read, edit, create and upload), display a "login to do this action"
2500                 // error if all of the following conditions are met:
2501                 // 1. the user is not logged in
2502                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2503                 // 3. the error can be avoided simply by logging in
2504                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2505                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2506                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2507                         && ( User::groupHasPermission( 'user', $action )
2508                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2509                 ) {
2510                         $displayReturnto = null;
2511
2512                         # Due to T34276, if a user does not have read permissions,
2513                         # $this->getTitle() will just give Special:Badtitle, which is
2514                         # not especially useful as a returnto parameter. Use the title
2515                         # from the request instead, if there was one.
2516                         $request = $this->getRequest();
2517                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2518                         if ( $action == 'edit' ) {
2519                                 $msg = 'whitelistedittext';
2520                                 $displayReturnto = $returnto;
2521                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2522                                 $msg = 'nocreatetext';
2523                         } elseif ( $action == 'upload' ) {
2524                                 $msg = 'uploadnologintext';
2525                         } else { # Read
2526                                 $msg = 'loginreqpagetext';
2527                                 $displayReturnto = Title::newMainPage();
2528                         }
2529
2530                         $query = [];
2531
2532                         if ( $returnto ) {
2533                                 $query['returnto'] = $returnto->getPrefixedText();
2534
2535                                 if ( !$request->wasPosted() ) {
2536                                         $returntoquery = $request->getValues();
2537                                         unset( $returntoquery['title'] );
2538                                         unset( $returntoquery['returnto'] );
2539                                         unset( $returntoquery['returntoquery'] );
2540                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2541                                 }
2542                         }
2543                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2544                         $loginLink = $linkRenderer->makeKnownLink(
2545                                 SpecialPage::getTitleFor( 'Userlogin' ),
2546                                 $this->msg( 'loginreqlink' )->text(),
2547                                 [],
2548                                 $query
2549                         );
2550
2551                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2552                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2553
2554                         # Don't return to a page the user can't read otherwise
2555                         # we'll end up in a pointless loop
2556                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2557                                 $this->returnToMain( null, $displayReturnto );
2558                         }
2559                 } else {
2560                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2561                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2562                 }
2563         }
2564
2565         /**
2566          * Display an error page indicating that a given version of MediaWiki is
2567          * required to use it
2568          *
2569          * @param mixed $version The version of MediaWiki needed to use the page
2570          */
2571         public function versionRequired( $version ) {
2572                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2573
2574                 $this->addWikiMsg( 'versionrequiredtext', $version );
2575                 $this->returnToMain();
2576         }
2577
2578         /**
2579          * Format a list of error messages
2580          *
2581          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2582          * @param string $action Action that was denied or null if unknown
2583          * @return string The wikitext error-messages, formatted into a list.
2584          */
2585         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2586                 if ( $action == null ) {
2587                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2588                 } else {
2589                         $action_desc = $this->msg( "action-$action" )->plain();
2590                         $text = $this->msg(
2591                                 'permissionserrorstext-withaction',
2592                                 count( $errors ),
2593                                 $action_desc
2594                         )->plain() . "\n\n";
2595                 }
2596
2597                 if ( count( $errors ) > 1 ) {
2598                         $text .= '<ul class="permissions-errors">' . "\n";
2599
2600                         foreach ( $errors as $error ) {
2601                                 $text .= '<li>';
2602                                 $text .= call_user_func_array( [ $this, 'msg' ], $error )->plain();
2603                                 $text .= "</li>\n";
2604                         }
2605                         $text .= '</ul>';
2606                 } else {
2607                         $text .= "<div class=\"permissions-errors\">\n" .
2608                                         call_user_func_array( [ $this, 'msg' ], reset( $errors ) )->plain() .
2609                                         "\n</div>";
2610                 }
2611
2612                 return $text;
2613         }
2614
2615         /**
2616          * Show a warning about replica DB lag
2617          *
2618          * If the lag is higher than $wgSlaveLagCritical seconds,
2619          * then the warning is a bit more obvious. If the lag is
2620          * lower than $wgSlaveLagWarning, then no warning is shown.
2621          *
2622          * @param int $lag Slave lag
2623          */
2624         public function showLagWarning( $lag ) {
2625                 $config = $this->getConfig();
2626                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2627                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2628                         $message = $lag < $config->get( 'SlaveLagCritical' )
2629                                 ? 'lag-warn-normal'
2630                                 : 'lag-warn-high';
2631                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2632                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2633                 }
2634         }
2635
2636         public function showFatalError( $message ) {
2637                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2638
2639                 $this->addHTML( $message );
2640         }
2641
2642         public function showUnexpectedValueError( $name, $val ) {
2643                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2644         }
2645
2646         public function showFileCopyError( $old, $new ) {
2647                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2648         }
2649
2650         public function showFileRenameError( $old, $new ) {
2651                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2652         }
2653
2654         public function showFileDeleteError( $name ) {
2655                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2656         }
2657
2658         public function showFileNotFoundError( $name ) {
2659                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2660         }
2661
2662         /**
2663          * Add a "return to" link pointing to a specified title
2664          *
2665          * @param Title $title Title to link
2666          * @param array $query Query string parameters
2667          * @param string $text Text of the link (input is not escaped)
2668          * @param array $options Options array to pass to Linker
2669          */
2670         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2671                 $linkRenderer = MediaWikiServices::getInstance()
2672                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
2673                 $link = $this->msg( 'returnto' )->rawParams(
2674                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
2675                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2676         }
2677
2678         /**
2679          * Add a "return to" link pointing to a specified title,
2680          * or the title indicated in the request, or else the main page
2681          *
2682          * @param mixed $unused
2683          * @param Title|string $returnto Title or String to return to
2684          * @param string $returntoquery Query string for the return to link
2685          */
2686         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2687                 if ( $returnto == null ) {
2688                         $returnto = $this->getRequest()->getText( 'returnto' );
2689                 }
2690
2691                 if ( $returntoquery == null ) {
2692                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2693                 }
2694
2695                 if ( $returnto === '' ) {
2696                         $returnto = Title::newMainPage();
2697                 }
2698
2699                 if ( is_object( $returnto ) ) {
2700                         $titleObj = $returnto;
2701                 } else {
2702                         $titleObj = Title::newFromText( $returnto );
2703                 }
2704                 // We don't want people to return to external interwiki. That
2705                 // might potentially be used as part of a phishing scheme
2706                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
2707                         $titleObj = Title::newMainPage();
2708                 }
2709
2710                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2711         }
2712
2713         private function getRlClientContext() {
2714                 if ( !$this->rlClientContext ) {
2715                         $query = ResourceLoader::makeLoaderQuery(
2716                                 [], // modules; not relevant
2717                                 $this->getLanguage()->getCode(),
2718                                 $this->getSkin()->getSkinName(),
2719                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2720                                 null, // version; not relevant
2721                                 ResourceLoader::inDebugMode(),
2722                                 null, // only; not relevant
2723                                 $this->isPrintable(),
2724                                 $this->getRequest()->getBool( 'handheld' )
2725                         );
2726                         $this->rlClientContext = new ResourceLoaderContext(
2727                                 $this->getResourceLoader(),
2728                                 new FauxRequest( $query )
2729                         );
2730                 }
2731                 return $this->rlClientContext;
2732         }
2733
2734         /**
2735          * Call this to freeze the module queue and JS config and create a formatter.
2736          *
2737          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2738          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2739          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2740          * the module filters retroactively. Skins and extension hooks may also add modules until very
2741          * late in the request lifecycle.
2742          *
2743          * @return ResourceLoaderClientHtml
2744          */
2745         public function getRlClient() {
2746                 if ( !$this->rlClient ) {
2747                         $context = $this->getRlClientContext();
2748                         $rl = $this->getResourceLoader();
2749                         $this->addModules( [
2750                                 'user.options',
2751                                 'user.tokens',
2752                         ] );
2753                         $this->addModuleStyles( [
2754                                 'site.styles',
2755                                 'noscript',
2756                                 'user.styles',
2757                         ] );
2758                         $this->getSkin()->setupSkinUserCss( $this );
2759
2760                         // Prepare exempt modules for buildExemptModules()
2761                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2762                         $exemptStates = [];
2763                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2764
2765                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2766                         // Separate user-specific batch for improved cache-hit ratio.
2767                         $userBatch = [ 'user.styles', 'user' ];
2768                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2769                         $dbr = wfGetDB( DB_REPLICA );
2770                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2771                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2772
2773                         // Filter out modules handled by buildExemptModules()
2774                         $moduleStyles = array_filter( $moduleStyles,
2775                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2776                                         $module = $rl->getModule( $name );
2777                                         if ( $module ) {
2778                                                 if ( $name === 'user.styles' && $this->isUserCssPreview() ) {
2779                                                         $exemptStates[$name] = 'ready';
2780                                                         // Special case in buildExemptModules()
2781                                                         return false;
2782                                                 }
2783                                                 $group = $module->getGroup();
2784                                                 if ( isset( $exemptGroups[$group] ) ) {
2785                                                         $exemptStates[$name] = 'ready';
2786                                                         if ( !$module->isKnownEmpty( $context ) ) {
2787                                                                 // E.g. Don't output empty <styles>
2788                                                                 $exemptGroups[$group][] = $name;
2789                                                         }
2790                                                         return false;
2791                                                 }
2792                                         }
2793                                         return true;
2794                                 }
2795                         );
2796                         $this->rlExemptStyleModules = $exemptGroups;
2797
2798                         $isUserModuleFiltered = !$this->filterModules( [ 'user' ] );
2799                         // If this page filters out 'user', makeResourceLoaderLink will drop it.
2800                         // Avoid indefinite "loading" state or untrue "ready" state (T145368).
2801                         if ( !$isUserModuleFiltered ) {
2802                                 // Manually handled by getBottomScripts()
2803                                 $userModule = $rl->getModule( 'user' );
2804                                 $userState = $userModule->isKnownEmpty( $context ) && !$this->isUserJsPreview()
2805                                         ? 'ready'
2806                                         : 'loading';
2807                                 $this->rlUserModuleState = $exemptStates['user'] = $userState;
2808                         }
2809
2810                         $rlClient = new ResourceLoaderClientHtml( $context, $this->getTarget() );
2811                         $rlClient->setConfig( $this->getJSVars() );
2812                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2813                         $rlClient->setModuleStyles( $moduleStyles );
2814                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2815                         $rlClient->setExemptStates( $exemptStates );
2816                         $this->rlClient = $rlClient;
2817                 }
2818                 return $this->rlClient;
2819         }
2820
2821         /**
2822          * @param Skin $sk The given Skin
2823          * @param bool $includeStyle Unused
2824          * @return string The doctype, opening "<html>", and head element.
2825          */
2826         public function headElement( Skin $sk, $includeStyle = true ) {
2827                 global $wgContLang;
2828
2829                 $userdir = $this->getLanguage()->getDir();
2830                 $sitedir = $wgContLang->getDir();
2831
2832                 $pieces = [];
2833                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2834                         $this->getRlClient()->getDocumentAttributes(),
2835                         $sk->getHtmlElementAttributes()
2836                 ) );
2837                 $pieces[] = Html::openElement( 'head' );
2838
2839                 if ( $this->getHTMLTitle() == '' ) {
2840                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2841                 }
2842
2843                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2844                         // Add <meta charset="UTF-8">
2845                         // This should be before <title> since it defines the charset used by
2846                         // text including the text inside <title>.
2847                         // The spec recommends defining XHTML5's charset using the XML declaration
2848                         // instead of meta.
2849                         // Our XML declaration is output by Html::htmlHeader.
2850                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2851                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2852                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2853                 }
2854
2855                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2856                 $pieces[] = $this->getRlClient()->getHeadHtml();
2857                 $pieces[] = $this->buildExemptModules();
2858                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2859                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2860
2861                 // Use an IE conditional comment to serve the script only to old IE
2862                 $pieces[] = '<!--[if lt IE 9]>' .
2863                         ResourceLoaderClientHtml::makeLoad(
2864                                 ResourceLoaderContext::newDummyContext(),
2865                                 [ 'html5shiv' ],
2866                                 ResourceLoaderModule::TYPE_SCRIPTS,
2867                                 [ 'sync' => true ]
2868                         ) .
2869                         '<![endif]-->';
2870
2871                 $pieces[] = Html::closeElement( 'head' );
2872
2873                 $bodyClasses = $this->mAdditionalBodyClasses;
2874                 $bodyClasses[] = 'mediawiki';
2875
2876                 # Classes for LTR/RTL directionality support
2877                 $bodyClasses[] = $userdir;
2878                 $bodyClasses[] = "sitedir-$sitedir";
2879
2880                 $underline = $this->getUser()->getOption( 'underline' );
2881                 if ( $underline < 2 ) {
2882                         // The following classes can be used here:
2883                         // * mw-underline-always
2884                         // * mw-underline-never
2885                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2886                 }
2887
2888                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2889                         # A <body> class is probably not the best way to do this . . .
2890                         $bodyClasses[] = 'capitalize-all-nouns';
2891                 }
2892
2893                 // Parser feature migration class
2894                 // The idea is that this will eventually be removed, after the wikitext
2895                 // which requires it is cleaned up.
2896                 $bodyClasses[] = 'mw-hide-empty-elt';
2897
2898                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2899                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2900                 $bodyClasses[] =
2901                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2902
2903                 $bodyAttrs = [];
2904                 // While the implode() is not strictly needed, it's used for backwards compatibility
2905                 // (this used to be built as a string and hooks likely still expect that).
2906                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2907
2908                 // Allow skins and extensions to add body attributes they need
2909                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2910                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2911
2912                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2913
2914                 return self::combineWrappedStrings( $pieces );
2915         }
2916
2917         /**
2918          * Get a ResourceLoader object associated with this OutputPage
2919          *
2920          * @return ResourceLoader
2921          */
2922         public function getResourceLoader() {
2923                 if ( is_null( $this->mResourceLoader ) ) {
2924                         $this->mResourceLoader = new ResourceLoader(
2925                                 $this->getConfig(),
2926                                 LoggerFactory::getInstance( 'resourceloader' )
2927                         );
2928                 }
2929                 return $this->mResourceLoader;
2930         }
2931
2932         /**
2933          * Explicily load or embed modules on a page.
2934          *
2935          * @param array|string $modules One or more module names
2936          * @param string $only ResourceLoaderModule TYPE_ class constant
2937          * @param array $extraQuery [optional] Array with extra query parameters for the request
2938          * @return string|WrappedStringList HTML
2939          */
2940         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2941                 // Apply 'target' and 'origin' filters
2942                 $modules = $this->filterModules( (array)$modules, null, $only );
2943
2944                 return ResourceLoaderClientHtml::makeLoad(
2945                         $this->getRlClientContext(),
2946                         $modules,
2947                         $only,
2948                         $extraQuery
2949                 );
2950         }
2951
2952         /**
2953          * Combine WrappedString chunks and filter out empty ones
2954          *
2955          * @param array $chunks
2956          * @return string|WrappedStringList HTML
2957          */
2958         protected static function combineWrappedStrings( array $chunks ) {
2959                 // Filter out empty values
2960                 $chunks = array_filter( $chunks, 'strlen' );
2961                 return WrappedString::join( "\n", $chunks );
2962         }
2963
2964         private function isUserJsPreview() {
2965                 return $this->getConfig()->get( 'AllowUserJs' )
2966                         && $this->getTitle()
2967                         && $this->getTitle()->isJsSubpage()
2968                         && $this->userCanPreview();
2969         }
2970
2971         protected function isUserCssPreview() {
2972                 return $this->getConfig()->get( 'AllowUserCss' )
2973                         && $this->getTitle()
2974                         && $this->getTitle()->isCssSubpage()
2975                         && $this->userCanPreview();
2976         }
2977
2978         /**
2979          * JS stuff to put at the bottom of the `<body>`.
2980          * These are legacy scripts ($this->mScripts), and user JS.
2981          *
2982          * @return string|WrappedStringList HTML
2983          */
2984         public function getBottomScripts() {
2985                 $chunks = [];
2986                 $chunks[] = $this->getRlClient()->getBodyHtml();
2987
2988                 // Legacy non-ResourceLoader scripts
2989                 $chunks[] = $this->mScripts;
2990
2991                 // Exempt 'user' module
2992                 // - May need excludepages for live preview. (T28283)
2993                 // - Must use TYPE_COMBINED so its response is handled by mw.loader.implement() which
2994                 //   ensures execution is scheduled after the "site" module.
2995                 // - Don't load if module state is already resolved as "ready".
2996                 if ( $this->rlUserModuleState === 'loading' ) {
2997                         if ( $this->isUserJsPreview() ) {
2998                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED,
2999                                         [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3000                                 );
3001                                 $chunks[] = ResourceLoader::makeInlineScript(
3002                                         Xml::encodeJsCall( 'mw.loader.using', [
3003                                                 [ 'user', 'site' ],
3004                                                 new XmlJsCode(
3005                                                         'function () {'
3006                                                                 . Xml::encodeJsCall( '$.globalEval', [
3007                                                                         $this->getRequest()->getText( 'wpTextbox1' )
3008                                                                 ] )
3009                                                                 . '}'
3010                                                 )
3011                                         ] )
3012                                 );
3013                                 // FIXME: If the user is previewing, say, ./vector.js, his ./common.js will be loaded
3014                                 // asynchronously and may arrive *after* the inline script here. So the previewed code
3015                                 // may execute before ./common.js runs. Normally, ./common.js runs before ./vector.js.
3016                                 // Similarly, when previewing ./common.js and the user module does arrive first,
3017                                 // it will arrive without common.js and the inline script runs after.
3018                                 // Thus running common after the excluded subpage.
3019                         } else {
3020                                 // Load normally
3021                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED );
3022                         }
3023                 }
3024
3025                 if ( $this->limitReportJSData ) {
3026                         $chunks[] = ResourceLoader::makeInlineScript(
3027                                 ResourceLoader::makeConfigSetScript(
3028                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3029                                 )
3030                         );
3031                 }
3032
3033                 return self::combineWrappedStrings( $chunks );
3034         }
3035
3036         /**
3037          * Get the javascript config vars to include on this page
3038          *
3039          * @return array Array of javascript config vars
3040          * @since 1.23
3041          */
3042         public function getJsConfigVars() {
3043                 return $this->mJsConfigVars;
3044         }
3045
3046         /**
3047          * Add one or more variables to be set in mw.config in JavaScript
3048          *
3049          * @param string|array $keys Key or array of key/value pairs
3050          * @param mixed $value [optional] Value of the configuration variable
3051          */
3052         public function addJsConfigVars( $keys, $value = null ) {
3053                 if ( is_array( $keys ) ) {
3054                         foreach ( $keys as $key => $value ) {
3055                                 $this->mJsConfigVars[$key] = $value;
3056                         }
3057                         return;
3058                 }
3059
3060                 $this->mJsConfigVars[$keys] = $value;
3061         }
3062
3063         /**
3064          * Get an array containing the variables to be set in mw.config in JavaScript.
3065          *
3066          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3067          * - in other words, page-independent/site-wide variables (without state).
3068          * You will only be adding bloat to the html page and causing page caches to
3069          * have to be purged on configuration changes.
3070          * @return array
3071          */
3072         public function getJSVars() {
3073                 global $wgContLang;
3074
3075                 $curRevisionId = 0;
3076                 $articleId = 0;
3077                 $canonicalSpecialPageName = false; # T23115
3078
3079                 $title = $this->getTitle();
3080                 $ns = $title->getNamespace();
3081                 $canonicalNamespace = MWNamespace::exists( $ns )
3082                         ? MWNamespace::getCanonicalName( $ns )
3083                         : $title->getNsText();
3084
3085                 $sk = $this->getSkin();
3086                 // Get the relevant title so that AJAX features can use the correct page name
3087                 // when making API requests from certain special pages (T36972).
3088                 $relevantTitle = $sk->getRelevantTitle();
3089                 $relevantUser = $sk->getRelevantUser();
3090
3091                 if ( $ns == NS_SPECIAL ) {
3092                         list( $canonicalSpecialPageName, /*...*/ ) =
3093                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3094                 } elseif ( $this->canUseWikiPage() ) {
3095                         $wikiPage = $this->getWikiPage();
3096                         $curRevisionId = $wikiPage->getLatest();
3097                         $articleId = $wikiPage->getId();
3098                 }
3099
3100                 $lang = $title->getPageViewLanguage();
3101
3102                 // Pre-process information
3103                 $separatorTransTable = $lang->separatorTransformTable();
3104                 $separatorTransTable = $separatorTransTable ? $separatorTransTable : [];
3105                 $compactSeparatorTransTable = [
3106                         implode( "\t", array_keys( $separatorTransTable ) ),
3107                         implode( "\t", $separatorTransTable ),
3108                 ];
3109                 $digitTransTable = $lang->digitTransformTable();
3110                 $digitTransTable = $digitTransTable ? $digitTransTable : [];
3111                 $compactDigitTransTable = [
3112                         implode( "\t", array_keys( $digitTransTable ) ),
3113                         implode( "\t", $digitTransTable ),
3114                 ];
3115
3116                 $user = $this->getUser();
3117
3118                 $vars = [
3119                         'wgCanonicalNamespace' => $canonicalNamespace,
3120                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3121                         'wgNamespaceNumber' => $title->getNamespace(),
3122                         'wgPageName' => $title->getPrefixedDBkey(),
3123                         'wgTitle' => $title->getText(),
3124                         'wgCurRevisionId' => $curRevisionId,
3125                         'wgRevisionId' => (int)$this->getRevisionId(),
3126                         'wgArticleId' => $articleId,
3127                         'wgIsArticle' => $this->isArticle(),
3128                         'wgIsRedirect' => $title->isRedirect(),
3129                         'wgAction' => Action::getActionName( $this->getContext() ),
3130                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3131                         'wgUserGroups' => $user->getEffectiveGroups(),
3132                         'wgCategories' => $this->getCategories(),
3133                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3134                         'wgPageContentLanguage' => $lang->getCode(),
3135                         'wgPageContentModel' => $title->getContentModel(),
3136                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3137                         'wgDigitTransformTable' => $compactDigitTransTable,
3138                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3139                         'wgMonthNames' => $lang->getMonthNamesArray(),
3140                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3141                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3142                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3143                         'wgRequestId' => WebRequest::getRequestId(),
3144                 ];
3145
3146                 if ( $user->isLoggedIn() ) {
3147                         $vars['wgUserId'] = $user->getId();
3148                         $vars['wgUserEditCount'] = $user->getEditCount();
3149                         $userReg = $user->getRegistration();
3150                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3151                         // Get the revision ID of the oldest new message on the user's talk
3152                         // page. This can be used for constructing new message alerts on
3153                         // the client side.
3154                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3155                 }
3156
3157                 if ( $wgContLang->hasVariants() ) {
3158                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3159                 }
3160                 // Same test as SkinTemplate
3161                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3162                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3163
3164                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3165                         && $relevantTitle->quickUserCan( 'edit', $user )
3166                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3167
3168                 foreach ( $title->getRestrictionTypes() as $type ) {
3169                         // Following keys are set in $vars:
3170                         // wgRestrictionCreate, wgRestrictionEdit, wgRestrictionMove, wgRestrictionUpload
3171                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3172                 }
3173
3174                 if ( $title->isMainPage() ) {
3175                         $vars['wgIsMainPage'] = true;
3176                 }
3177
3178                 if ( $this->mRedirectedFrom ) {
3179                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3180                 }
3181
3182                 if ( $relevantUser ) {
3183                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3184                 }
3185
3186                 // Allow extensions to add their custom variables to the mw.config map.
3187                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3188                 // page-dependant but site-wide (without state).
3189                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3190                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3191
3192                 // Merge in variables from addJsConfigVars last
3193                 return array_merge( $vars, $this->getJsConfigVars() );
3194         }
3195
3196         /**
3197          * To make it harder for someone to slip a user a fake
3198          * user-JavaScript or user-CSS preview, a random token
3199          * is associated with the login session. If it's not
3200          * passed back with the preview request, we won't render
3201          * the code.
3202          *
3203          * @return bool
3204          */
3205         public function userCanPreview() {
3206                 $request = $this->getRequest();
3207                 if (
3208                         $request->getVal( 'action' ) !== 'submit' ||
3209                         !$request->getCheck( 'wpPreview' ) ||
3210                         !$request->wasPosted()
3211                 ) {
3212                         return false;
3213                 }
3214
3215                 $user = $this->getUser();
3216
3217                 if ( !$user->isLoggedIn() ) {
3218                         // Anons have predictable edit tokens
3219                         return false;
3220                 }
3221                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3222                         return false;
3223                 }
3224
3225                 $title = $this->getTitle();
3226                 if ( !$title->isJsSubpage() && !$title->isCssSubpage() ) {
3227                         return false;
3228                 }
3229                 if ( !$title->isSubpageOf( $user->getUserPage() ) ) {
3230                         // Don't execute another user's CSS or JS on preview (T85855)
3231                         return false;
3232                 }
3233
3234                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3235                 if ( count( $errors ) !== 0 ) {
3236                         return false;
3237                 }
3238
3239                 return true;
3240         }
3241
3242         /**
3243          * @return array Array in format "link name or number => 'link html'".
3244          */
3245         public function getHeadLinksArray() {
3246                 global $wgVersion;
3247
3248                 $tags = [];
3249                 $config = $this->getConfig();
3250
3251                 $canonicalUrl = $this->mCanonicalUrl;
3252
3253                 $tags['meta-generator'] = Html::element( 'meta', [
3254                         'name' => 'generator',
3255                         'content' => "MediaWiki $wgVersion",
3256                 ] );
3257
3258                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3259                         // Per https://w3c.github.io/webappsec-referrer-policy/#unknown-policy-values
3260                         // fallbacks should come before the primary value so we need to reverse the array.
3261                         foreach ( array_reverse( (array)$config->get( 'ReferrerPolicy' ) ) as $i => $policy ) {
3262                                 $tags["meta-referrer-$i"] = Html::element( 'meta', [
3263                                         'name' => 'referrer',
3264                                         'content' => $policy,
3265                                 ] );
3266                         }
3267                 }
3268
3269                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3270                 if ( $p !== 'index,follow' ) {
3271                         // http://www.robotstxt.org/wc/meta-user.html
3272                         // Only show if it's different from the default robots policy
3273                         $tags['meta-robots'] = Html::element( 'meta', [
3274                                 'name' => 'robots',
3275                                 'content' => $p,
3276                         ] );
3277                 }
3278
3279                 foreach ( $this->mMetatags as $tag ) {
3280                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3281                                 $a = 'http-equiv';
3282                                 $tag[0] = substr( $tag[0], 5 );
3283                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3284                                 $a = 'property';
3285                         } else {
3286                                 $a = 'name';
3287                         }
3288                         $tagName = "meta-{$tag[0]}";
3289                         if ( isset( $tags[$tagName] ) ) {
3290                                 $tagName .= $tag[1];
3291                         }
3292                         $tags[$tagName] = Html::element( 'meta',
3293                                 [
3294                                         $a => $tag[0],
3295                                         'content' => $tag[1]
3296                                 ]
3297                         );
3298                 }
3299
3300                 foreach ( $this->mLinktags as $tag ) {
3301                         $tags[] = Html::element( 'link', $tag );
3302                 }
3303
3304                 # Universal edit button
3305                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3306                         $user = $this->getUser();
3307                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3308                                 && ( $this->getTitle()->exists() ||
3309                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3310                         ) {
3311                                 // Original UniversalEditButton
3312                                 $msg = $this->msg( 'edit' )->text();
3313                                 $tags['universal-edit-button'] = Html::element( 'link', [
3314                                         'rel' => 'alternate',
3315                                         'type' => 'application/x-wiki',
3316                                         'title' => $msg,
3317                                         'href' => $this->getTitle()->getEditURL(),
3318                                 ] );
3319                                 // Alternate edit link
3320                                 $tags['alternative-edit'] = Html::element( 'link', [
3321                                         'rel' => 'edit',
3322                                         'title' => $msg,
3323                                         'href' => $this->getTitle()->getEditURL(),
3324                                 ] );
3325                         }
3326                 }
3327
3328                 # Generally the order of the favicon and apple-touch-icon links
3329                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3330                 # uses whichever one appears later in the HTML source. Make sure
3331                 # apple-touch-icon is specified first to avoid this.
3332                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3333                         $tags['apple-touch-icon'] = Html::element( 'link', [
3334                                 'rel' => 'apple-touch-icon',
3335                                 'href' => $config->get( 'AppleTouchIcon' )
3336                         ] );
3337                 }
3338
3339                 if ( $config->get( 'Favicon' ) !== false ) {
3340                         $tags['favicon'] = Html::element( 'link', [
3341                                 'rel' => 'shortcut icon',
3342                                 'href' => $config->get( 'Favicon' )
3343                         ] );
3344                 }
3345
3346                 # OpenSearch description link
3347                 $tags['opensearch'] = Html::element( 'link', [
3348                         'rel' => 'search',
3349                         'type' => 'application/opensearchdescription+xml',
3350                         'href' => wfScript( 'opensearch_desc' ),
3351                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3352                 ] );
3353
3354                 if ( $config->get( 'EnableAPI' ) ) {
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 $wgServer is protocol-relative.
3363                                 // Whether RSD accepts relative or protocol-relative URLs is completely
3364                                 // undocumented, though.
3365                                 'href' => wfExpandUrl( wfAppendQuery(
3366                                         wfScript( 'api' ),
3367                                         [ 'action' => 'rsd' ] ),
3368                                         PROTO_RELATIVE
3369                                 ),
3370                         ] );
3371                 }
3372
3373                 # Language variants
3374                 if ( !$config->get( 'DisableLangConversion' ) ) {
3375                         $lang = $this->getTitle()->getPageLanguage();
3376                         if ( $lang->hasVariants() ) {
3377                                 $variants = $lang->getVariants();
3378                                 foreach ( $variants as $variant ) {
3379                                         $tags["variant-$variant"] = Html::element( 'link', [
3380                                                 'rel' => 'alternate',
3381                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3382                                                 'href' => $this->getTitle()->getLocalURL(
3383                                                         [ 'variant' => $variant ] )
3384                                                 ]
3385                                         );
3386                                 }
3387                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3388                                 $tags["variant-x-default"] = Html::element( 'link', [
3389                                         'rel' => 'alternate',
3390                                         'hreflang' => 'x-default',
3391                                         'href' => $this->getTitle()->getLocalURL() ] );
3392                         }
3393                 }
3394
3395                 # Copyright
3396                 if ( $this->copyrightUrl !== null ) {
3397                         $copyright = $this->copyrightUrl;
3398                 } else {
3399                         $copyright = '';
3400                         if ( $config->get( 'RightsPage' ) ) {
3401                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3402
3403                                 if ( $copy ) {
3404                                         $copyright = $copy->getLocalURL();
3405                                 }
3406                         }
3407
3408                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3409                                 $copyright = $config->get( 'RightsUrl' );
3410                         }
3411                 }
3412
3413                 if ( $copyright ) {
3414                         $tags['copyright'] = Html::element( 'link', [
3415                                 'rel' => 'license',
3416                                 'href' => $copyright ]
3417                         );
3418                 }
3419
3420                 # Feeds
3421                 if ( $config->get( 'Feed' ) ) {
3422                         $feedLinks = [];
3423
3424                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3425                                 # Use the page name for the title.  In principle, this could
3426                                 # lead to issues with having the same name for different feeds
3427                                 # corresponding to the same page, but we can't avoid that at
3428                                 # this low a level.
3429
3430                                 $feedLinks[] = $this->feedLink(
3431                                         $format,
3432                                         $link,
3433                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3434                                         $this->msg(
3435                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3436                                         )->text()
3437                                 );
3438                         }
3439
3440                         # Recent changes feed should appear on every page (except recentchanges,
3441                         # that would be redundant). Put it after the per-page feed to avoid
3442                         # changing existing behavior. It's still available, probably via a
3443                         # menu in your browser. Some sites might have a different feed they'd
3444                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3445                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3446                         # If so, use it instead.
3447                         $sitename = $config->get( 'Sitename' );
3448                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3449                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3450                                         // Note, this->feedLink escapes the url.
3451                                         $feedLinks[] = $this->feedLink(
3452                                                 $type,
3453                                                 $feedUrl,
3454                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3455                                         );
3456                                 }
3457                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3458                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3459                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3460                                         $feedLinks[] = $this->feedLink(
3461                                                 $format,
3462                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3463                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3464                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3465                                         );
3466                                 }
3467                         }
3468
3469                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3470                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3471                         # use OutputPage::addFeedLink() instead.
3472                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3473
3474                         $tags += $feedLinks;
3475                 }
3476
3477                 # Canonical URL
3478                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3479                         if ( $canonicalUrl !== false ) {
3480                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3481                         } else {
3482                                 if ( $this->isArticleRelated() ) {
3483                                         // This affects all requests where "setArticleRelated" is true. This is
3484                                         // typically all requests that show content (query title, curid, oldid, diff),
3485                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3486                                         // It does not apply to File pages and Special pages.
3487                                         // 'history' and 'info' actions address page metadata rather than the page
3488                                         // content itself, so they may not be canonicalized to the view page url.
3489                                         // TODO: this ought to be better encapsulated in the Action class.
3490                                         $action = Action::getActionName( $this->getContext() );
3491                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3492                                                 $query = "action={$action}";
3493                                         } else {
3494                                                 $query = '';
3495                                         }
3496                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3497                                 } else {
3498                                         $reqUrl = $this->getRequest()->getRequestURL();
3499                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3500                                 }
3501                         }
3502                 }
3503                 if ( $canonicalUrl !== false ) {
3504                         $tags[] = Html::element( 'link', [
3505                                 'rel' => 'canonical',
3506                                 'href' => $canonicalUrl
3507                         ] );
3508                 }
3509
3510                 return $tags;
3511         }
3512
3513         /**
3514          * Generate a "<link rel/>" for a feed.
3515          *
3516          * @param string $type Feed type
3517          * @param string $url URL to the feed
3518          * @param string $text Value of the "title" attribute
3519          * @return string HTML fragment
3520          */
3521         private function feedLink( $type, $url, $text ) {
3522                 return Html::element( 'link', [
3523                         'rel' => 'alternate',
3524                         'type' => "application/$type+xml",
3525                         'title' => $text,
3526                         'href' => $url ]
3527                 );
3528         }
3529
3530         /**
3531          * Add a local or specified stylesheet, with the given media options.
3532          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3533          *
3534          * @param string $style URL to the file
3535          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3536          * @param string $condition For IE conditional comments, specifying an IE version
3537          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3538          */
3539         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3540                 $options = [];
3541                 if ( $media ) {
3542                         $options['media'] = $media;
3543                 }
3544                 if ( $condition ) {
3545                         $options['condition'] = $condition;
3546                 }
3547                 if ( $dir ) {
3548                         $options['dir'] = $dir;
3549                 }
3550                 $this->styles[$style] = $options;
3551         }
3552
3553         /**
3554          * Adds inline CSS styles
3555          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3556          *
3557          * @param mixed $style_css Inline CSS
3558          * @param string $flip Set to 'flip' to flip the CSS if needed
3559          */
3560         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3561                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3562                         # If wanted, and the interface is right-to-left, flip the CSS
3563                         $style_css = CSSJanus::transform( $style_css, true, false );
3564                 }
3565                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3566         }
3567
3568         /**
3569          * Build exempt modules and legacy non-ResourceLoader styles.
3570          *
3571          * @return string|WrappedStringList HTML
3572          */
3573         protected function buildExemptModules() {
3574                 global $wgContLang;
3575
3576                 $chunks = [];
3577                 // Things that go after the ResourceLoaderDynamicStyles marker
3578                 $append = [];
3579
3580                 // Exempt 'user' styles module (may need 'excludepages' for live preview)
3581                 if ( $this->isUserCssPreview() ) {
3582                         $append[] = $this->makeResourceLoaderLink(
3583                                 'user.styles',
3584                                 ResourceLoaderModule::TYPE_STYLES,
3585                                 [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3586                         );
3587
3588                         // Load the previewed CSS. Janus it if needed.
3589                         // User-supplied CSS is assumed to in the wiki's content language.
3590                         $previewedCSS = $this->getRequest()->getText( 'wpTextbox1' );
3591                         if ( $this->getLanguage()->getDir() !== $wgContLang->getDir() ) {
3592                                 $previewedCSS = CSSJanus::transform( $previewedCSS, true, false );
3593                         }
3594                         $append[] = Html::inlineStyle( $previewedCSS );
3595                 }
3596
3597                 // We want site, private and user styles to override dynamically added styles from
3598                 // general modules, but we want dynamically added styles to override statically added
3599                 // style modules. So the order has to be:
3600                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3601                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3602                 // - ResourceLoaderDynamicStyles marker
3603                 // - site/private/user styles
3604
3605                 // Add legacy styles added through addStyle()/addInlineStyle() here
3606                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3607
3608                 $chunks[] = Html::element(
3609                         'meta',
3610                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3611                 );
3612
3613                 $separateReq = [ 'site.styles', 'user.styles' ];
3614                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3615                         // Combinable modules
3616                         $chunks[] = $this->makeResourceLoaderLink(
3617                                 array_diff( $moduleNames, $separateReq ),
3618                                 ResourceLoaderModule::TYPE_STYLES
3619                         );
3620
3621                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3622                                 // These require their own dedicated request in order to support "@import"
3623                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3624                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3625                                         ResourceLoaderModule::TYPE_STYLES
3626                                 );
3627                         }
3628                 }
3629
3630                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3631         }
3632
3633         /**
3634          * @return array
3635          */
3636         public function buildCssLinksArray() {
3637                 $links = [];
3638
3639                 foreach ( $this->styles as $file => $options ) {
3640                         $link = $this->styleLink( $file, $options );
3641                         if ( $link ) {
3642                                 $links[$file] = $link;
3643                         }
3644                 }
3645                 return $links;
3646         }
3647
3648         /**
3649          * Generate \<link\> tags for stylesheets
3650          *
3651          * @param string $style URL to the file
3652          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3653          * @return string HTML fragment
3654          */
3655         protected function styleLink( $style, array $options ) {
3656                 if ( isset( $options['dir'] ) ) {
3657                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3658                                 return '';
3659                         }
3660                 }
3661
3662                 if ( isset( $options['media'] ) ) {
3663                         $media = self::transformCssMedia( $options['media'] );
3664                         if ( is_null( $media ) ) {
3665                                 return '';
3666                         }
3667                 } else {
3668                         $media = 'all';
3669                 }
3670
3671                 if ( substr( $style, 0, 1 ) == '/' ||
3672                         substr( $style, 0, 5 ) == 'http:' ||
3673                         substr( $style, 0, 6 ) == 'https:' ) {
3674                         $url = $style;
3675                 } else {
3676                         $config = $this->getConfig();
3677                         $url = $config->get( 'StylePath' ) . '/' . $style . '?' .
3678                                 $config->get( 'StyleVersion' );
3679                 }
3680
3681                 $link = Html::linkedStyle( $url, $media );
3682
3683                 if ( isset( $options['condition'] ) ) {
3684                         $condition = htmlspecialchars( $options['condition'] );
3685                         $link = "<!--[if $condition]>$link<![endif]-->";
3686                 }
3687                 return $link;
3688         }
3689
3690         /**
3691          * Transform path to web-accessible static resource.
3692          *
3693          * This is used to add a validation hash as query string.
3694          * This aids various behaviors:
3695          *
3696          * - Put long Cache-Control max-age headers on responses for improved
3697          *   cache performance.
3698          * - Get the correct version of a file as expected by the current page.
3699          * - Instantly get the updated version of a file after deployment.
3700          *
3701          * Avoid using this for urls included in HTML as otherwise clients may get different
3702          * versions of a resource when navigating the site depending on when the page was cached.
3703          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3704          * an external stylesheet).
3705          *
3706          * @since 1.27
3707          * @param Config $config
3708          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3709          * @return string URL
3710          */
3711         public static function transformResourcePath( Config $config, $path ) {
3712                 global $IP;
3713
3714                 $localDir = $IP;
3715                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3716                 if ( $remotePathPrefix === '' ) {
3717                         // The configured base path is required to be empty string for
3718                         // wikis in the domain root
3719                         $remotePath = '/';
3720                 } else {
3721                         $remotePath = $remotePathPrefix;
3722                 }
3723                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3724                         // - Path is outside wgResourceBasePath, ignore.
3725                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3726                         return $path;
3727                 }
3728                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3729                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3730                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3731                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3732                 $uploadPath = $config->get( 'UploadPath' );
3733                 if ( strpos( $path, $uploadPath ) === 0 ) {
3734                         $localDir = $config->get( 'UploadDirectory' );
3735                         $remotePathPrefix = $remotePath = $uploadPath;
3736                 }
3737
3738                 $path = RelPath::getRelativePath( $path, $remotePath );
3739                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3740         }
3741
3742         /**
3743          * Utility method for transformResourceFilePath().
3744          *
3745          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3746          *
3747          * @since 1.27
3748          * @param string $remotePathPrefix URL path prefix that points to $localPath
3749          * @param string $localPath File directory exposed at $remotePath
3750          * @param string $file Path to target file relative to $localPath
3751          * @return string URL
3752          */
3753         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3754                 $hash = md5_file( "$localPath/$file" );
3755                 if ( $hash === false ) {
3756                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3757                         $hash = '';
3758                 }
3759                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3760         }
3761
3762         /**
3763          * Transform "media" attribute based on request parameters
3764          *
3765          * @param string $media Current value of the "media" attribute
3766          * @return string Modified value of the "media" attribute, or null to skip
3767          * this stylesheet
3768          */
3769         public static function transformCssMedia( $media ) {
3770                 global $wgRequest;
3771
3772                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3773                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3774
3775                 // Switch in on-screen display for media testing
3776                 $switches = [
3777                         'printable' => 'print',
3778                         'handheld' => 'handheld',
3779                 ];
3780                 foreach ( $switches as $switch => $targetMedia ) {
3781                         if ( $wgRequest->getBool( $switch ) ) {
3782                                 if ( $media == $targetMedia ) {
3783                                         $media = '';
3784                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3785                                         /* This regex will not attempt to understand a comma-separated media_query_list
3786                                          *
3787                                          * Example supported values for $media:
3788                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3789                                          * Example NOT supported value for $media:
3790                                          * '3d-glasses, screen, print and resolution > 90dpi'
3791                                          *
3792                                          * If it's a print request, we never want any kind of screen stylesheets
3793                                          * If it's a handheld request (currently the only other choice with a switch),
3794                                          * we don't want simple 'screen' but we might want screen queries that
3795                                          * have a max-width or something, so we'll pass all others on and let the
3796                                          * client do the query.
3797                                          */
3798                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3799                                                 return null;
3800                                         }
3801                                 }
3802                         }
3803                 }
3804
3805                 return $media;
3806         }
3807
3808         /**
3809          * Add a wikitext-formatted message to the output.
3810          * This is equivalent to:
3811          *
3812          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3813          */
3814         public function addWikiMsg( /*...*/ ) {
3815                 $args = func_get_args();
3816                 $name = array_shift( $args );
3817                 $this->addWikiMsgArray( $name, $args );
3818         }
3819
3820         /**
3821          * Add a wikitext-formatted message to the output.
3822          * Like addWikiMsg() except the parameters are taken as an array
3823          * instead of a variable argument list.
3824          *
3825          * @param string $name
3826          * @param array $args
3827          */
3828         public function addWikiMsgArray( $name, $args ) {
3829                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3830         }
3831
3832         /**
3833          * This function takes a number of message/argument specifications, wraps them in
3834          * some overall structure, and then parses the result and adds it to the output.
3835          *
3836          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3837          * and so on. The subsequent arguments may be either
3838          * 1) strings, in which case they are message names, or
3839          * 2) arrays, in which case, within each array, the first element is the message
3840          *    name, and subsequent elements are the parameters to that message.
3841          *
3842          * Don't use this for messages that are not in the user's interface language.
3843          *
3844          * For example:
3845          *
3846          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3847          *
3848          * Is equivalent to:
3849          *
3850          *    $wgOut->addWikiText( "<div class='error'>\n"
3851          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3852          *
3853          * The newline after the opening div is needed in some wikitext. See T21226.
3854          *
3855          * @param string $wrap
3856          */
3857         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3858                 $msgSpecs = func_get_args();
3859                 array_shift( $msgSpecs );
3860                 $msgSpecs = array_values( $msgSpecs );
3861                 $s = $wrap;
3862                 foreach ( $msgSpecs as $n => $spec ) {
3863                         if ( is_array( $spec ) ) {
3864                                 $args = $spec;
3865                                 $name = array_shift( $args );
3866                                 if ( isset( $args['options'] ) ) {
3867                                         unset( $args['options'] );
3868                                         wfDeprecated(
3869                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3870                                                 '1.20'
3871                                         );
3872                                 }
3873                         } else {
3874                                 $args = [];
3875                                 $name = $spec;
3876                         }
3877                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3878                 }
3879                 $this->addWikiText( $s );
3880         }
3881
3882         /**
3883          * Whether the output has a table of contents
3884          * @return bool
3885          * @since 1.22
3886          */
3887         public function isTOCEnabled() {
3888                 return $this->mEnableTOC;
3889         }
3890
3891         /**
3892          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3893          * @param bool $flag
3894          * @since 1.23
3895          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3896          */
3897         public function enableSectionEditLinks( $flag = true ) {
3898                 $this->mEnableSectionEditLinks = $flag;
3899         }
3900
3901         /**
3902          * @return bool
3903          * @since 1.23
3904          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3905          */
3906         public function sectionEditLinksEnabled() {
3907                 return $this->mEnableSectionEditLinks;
3908         }
3909
3910         /**
3911          * Helper function to setup the PHP implementation of OOUI to use in this request.
3912          *
3913          * @since 1.26
3914          * @param String $skinName The Skin name to determine the correct OOUI theme
3915          * @param String $dir Language direction
3916          */
3917         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
3918                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
3919                 $theme = isset( $themes[$skinName] ) ? $themes[$skinName] : $themes['default'];
3920                 // For example, 'OOUI\WikimediaUITheme'.
3921                 $themeClass = "OOUI\\{$theme}Theme";
3922                 OOUI\Theme::setSingleton( new $themeClass() );
3923                 OOUI\Element::setDefaultDir( $dir );
3924         }
3925
3926         /**
3927          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3928          * MediaWiki and this OutputPage instance.
3929          *
3930          * @since 1.25
3931          */
3932         public function enableOOUI() {
3933                 self::setupOOUI(
3934                         strtolower( $this->getSkin()->getSkinName() ),
3935                         $this->getLanguage()->getDir()
3936                 );
3937                 $this->addModuleStyles( [
3938                         'oojs-ui-core.styles',
3939                         'oojs-ui.styles.indicators',
3940                         'oojs-ui.styles.textures',
3941                         'mediawiki.widgets.styles',
3942                         'oojs-ui.styles.icons-content',
3943                         'oojs-ui.styles.icons-alerts',
3944                         'oojs-ui.styles.icons-interactions',
3945                 ] );
3946         }
3947
3948         /**
3949          * Add Link headers for preloading the wiki's logo.
3950          *
3951          * @since 1.26
3952          */
3953         protected function addLogoPreloadLinkHeaders() {
3954                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
3955
3956                 $tags = [];
3957                 $logosPerDppx = [];
3958                 $logos = [];
3959
3960                 if ( !is_array( $logo ) ) {
3961                         // No media queries required if we only have one variant
3962                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
3963                         return;
3964                 }
3965
3966                 if ( isset( $logo['svg'] ) ) {
3967                         // No media queries required if we only have a 1x and svg variant
3968                         // because all preload-capable browsers support SVGs
3969                         $this->addLinkHeader( '<' . $logo['svg'] . '>;rel=preload;as=image' );
3970                         return;
3971                 }
3972
3973                 foreach ( $logo as $dppx => $src ) {
3974                         // Keys are in this format: "1.5x"
3975                         $dppx = substr( $dppx, 0, -1 );
3976                         $logosPerDppx[$dppx] = $src;
3977                 }
3978
3979                 // Because PHP can't have floats as array keys
3980                 uksort( $logosPerDppx, function ( $a , $b ) {
3981                         $a = floatval( $a );
3982                         $b = floatval( $b );
3983
3984                         if ( $a == $b ) {
3985                                 return 0;
3986                         }
3987                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
3988                         return ( $a < $b ) ? -1 : 1;
3989                 } );
3990
3991                 foreach ( $logosPerDppx as $dppx => $src ) {
3992                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
3993                 }
3994
3995                 $logosCount = count( $logos );
3996                 // Logic must match ResourceLoaderSkinModule:
3997                 // - 1x applies to resolution < 1.5dppx
3998                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
3999                 // - 2x applies to resolution >= 2dppx
4000                 // Note that min-resolution and max-resolution are both inclusive.
4001                 for ( $i = 0; $i < $logosCount; $i++ ) {
4002                         if ( $i === 0 ) {
4003                                 // Smallest dppx
4004                                 // min-resolution is ">=" (larger than or equal to)
4005                                 // "not min-resolution" is essentially "<"
4006                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
4007                         } elseif ( $i !== $logosCount - 1 ) {
4008                                 // In between
4009                                 // Media query expressions can only apply "not" to the entire expression
4010                                 // (e.g. can't express ">= 1.5 and not >= 2).
4011                                 // Workaround: Use <= 1.9999 in place of < 2.
4012                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
4013                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
4014                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
4015                         } else {
4016                                 // Largest dppx
4017                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
4018                         }
4019
4020                         $this->addLinkHeader(
4021                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
4022                         );
4023                 }
4024         }
4025 }