includes/OutputPage.php

   1 <?php
   2 /**
   3  * Preparation for the final page rendering.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use MediaWiki\Linker\LinkTarget;
  24 use MediaWiki\Logger\LoggerFactory;
  25 use MediaWiki\MediaWikiServices;
  26 use MediaWiki\Session\SessionManager;
  27 use Wikimedia\Rdbms\IResultWrapper;
  28 use Wikimedia\RelPath;
  29 use Wikimedia\WrappedString;
  30 use Wikimedia\WrappedStringList;
  31
  32 /**
  33  * This class should be covered by a general architecture document which does
  34  * not exist as of January 2011.  This is one of the Core classes and should
  35  * be read at least once by any new developers.
  36  *
  37  * This class is used to prepare the final rendering. A skin is then
  38  * applied to the output parameters (links, javascript, html, categories ...).
  39  *
  40  * @todo FIXME: Another class handles sending the whole page to the client.
  41  *
  42  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  43  * in November 2010.
  44  *
  45  * @todo document
  46  */
  47 class OutputPage extends ContextSource {
  48         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  49         protected $mMetatags = [];
  50
  51         /** @var array */
  52         protected $mLinktags = [];
  53
  54         /** @var bool */
  55         protected $mCanonicalUrl = false;
  56
  57         /**
  58          * @var string Should be private - has getter and setter. Contains
  59          *   the HTML title */
  60         public $mPagetitle = '';
  61
  62         /**
  63          * @var string Contains all of the "<body>" content. Should be private we
  64          *   got set/get accessors and the append() method.
  65          */
  66         public $mBodytext = '';
  67
  68         /** @var string Stores contents of "<title>" tag */
  69         private $mHTMLtitle = '';
  70
  71         /**
  72          * @var bool Is the displayed content related to the source of the
  73          *   corresponding wiki article.
  74          */
  75         private $mIsarticle = false;
  76
  77         /** @var bool Stores "article flag" toggle. */
  78         private $mIsArticleRelated = true;
  79
  80         /**
  81          * @var bool We have to set isPrintable(). Some pages should
  82          * never be printed (ex: redirections).
  83          */
  84         private $mPrintable = false;
  85
  86         /**
  87          * @var array Contains the page subtitle. Special pages usually have some
  88          *   links here. Don't confuse with site subtitle added by skins.
  89          */
  90         private $mSubtitle = [];
  91
  92         /** @var string */
  93         public $mRedirect = '';
  94
  95         /** @var int */
  96         protected $mStatusCode;
  97
  98         /**
  99          * @var string Used for sending cache control.
 100          *   The whole caching system should probably be moved into its own class.
 101          */
 102         protected $mLastModified = '';
 103
 104         /** @var array */
 105         protected $mCategoryLinks = [];
 106
 107         /** @var array */
 108         protected $mCategories = [
 109                 'hidden' => [],
 110                 'normal' => [],
 111         ];
 112
 113         /** @var array */
 114         protected $mIndicators = [];
 115
 116         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 117         private $mLanguageLinks = [];
 118
 119         /**
 120          * Used for JavaScript (predates ResourceLoader)
 121          * @todo We should split JS / CSS.
 122          * mScripts content is inserted as is in "<head>" by Skin. This might
 123          * contain either a link to a stylesheet or inline CSS.
 124          */
 125         private $mScripts = '';
 126
 127         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 128         protected $mInlineStyles = '';
 129
 130         /**
 131          * @var string Used by skin template.
 132          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 133          */
 134         public $mPageLinkTitle = '';
 135
 136         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 137         protected $mHeadItems = [];
 138
 139         /** @var array Additional <body> classes; there are also <body> classes from other sources */
 140         protected $mAdditionalBodyClasses = [];
 141
 142         /** @var array */
 143         protected $mModules = [];
 144
 145         /** @var array */
 146         protected $mModuleScripts = [];
 147
 148         /** @var array */
 149         protected $mModuleStyles = [];
 150
 151         /** @var ResourceLoader */
 152         protected $mResourceLoader;
 153
 154         /** @var ResourceLoaderClientHtml */
 155         private $rlClient;
 156
 157         /** @var ResourceLoaderContext */
 158         private $rlClientContext;
 159
 160         /** @var array */
 161         private $rlExemptStyleModules;
 162
 163         /** @var array */
 164         protected $mJsConfigVars = [];
 165
 166         /** @var array */
 167         protected $mTemplateIds = [];
 168
 169         /** @var array */
 170         protected $mImageTimeKeys = [];
 171
 172         /** @var string */
 173         public $mRedirectCode = '';
 174
 175         protected $mFeedLinksAppendQuery = null;
 176
 177         /** @var array
 178          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 179          * @see ResourceLoaderModule::$origin
 180          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 181          */
 182         protected $mAllowedModules = [
 183                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 184         ];
 185
 186         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 187         protected $mDoNothing = false;
 188
 189         // Parser related.
 190
 191         /** @var int */
 192         protected $mContainsNewMagic = 0;
 193
 194         /**
 195          * lazy initialised, use parserOptions()
 196          * @var ParserOptions
 197          */
 198         protected $mParserOptions = null;
 199
 200         /**
 201          * Handles the Atom / RSS links.
 202          * We probably only support Atom in 2011.
 203          * @see $wgAdvertisedFeedTypes
 204          */
 205         private $mFeedLinks = [];
 206
 207         // Gwicke work on squid caching? Roughly from 2003.
 208         protected $mEnableClientCache = true;
 209
 210         /** @var bool Flag if output should only contain the body of the article. */
 211         private $mArticleBodyOnly = false;
 212
 213         /** @var bool */
 214         protected $mNewSectionLink = false;
 215
 216         /** @var bool */
 217         protected $mHideNewSectionLink = false;
 218
 219         /**
 220          * @var bool Comes from the parser. This was probably made to load CSS/JS
 221          * only if we had "<gallery>". Used directly in CategoryPage.php.
 222          * Looks like ResourceLoader can replace this.
 223          */
 224         public $mNoGallery = false;
 225
 226         /** @var string */
 227         private $mPageTitleActionText = '';
 228
 229         /** @var int Cache stuff. Looks like mEnableClientCache */
 230         protected $mCdnMaxage = 0;
 231         /** @var int Upper limit on mCdnMaxage */
 232         protected $mCdnMaxageLimit = INF;
 233
 234         /**
 235          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 236          * be sent. This should be done for pages where edit actions are possible.
 237          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 238          */
 239         protected $mPreventClickjacking = true;
 240
 241         /** @var int To include the variable {{REVISIONID}} */
 242         private $mRevisionId = null;
 243
 244         /** @var string */
 245         private $mRevisionTimestamp = null;
 246
 247         /** @var array */
 248         protected $mFileVersion = null;
 249
 250         /**
 251          * @var array An array of stylesheet filenames (relative from skins path),
 252          * with options for CSS media, IE conditions, and RTL/LTR direction.
 253          * For internal use; add settings in the skin via $this->addStyle()
 254          *
 255          * Style again! This seems like a code duplication since we already have
 256          * mStyles. This is what makes Open Source amazing.
 257          */
 258         protected $styles = [];
 259
 260         private $mIndexPolicy = 'index';
 261         private $mFollowPolicy = 'follow';
 262         private $mVaryHeader = [
 263                 'Accept-Encoding' => [ 'match=gzip' ],
 264         ];
 265
 266         /**
 267          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 268          * of the redirect.
 269          *
 270          * @var Title
 271          */
 272         private $mRedirectedFrom = null;
 273
 274         /**
 275          * Additional key => value data
 276          */
 277         private $mProperties = [];
 278
 279         /**
 280          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 281          */
 282         private $mTarget = null;
 283
 284         /**
 285          * @var bool Whether parser output contains a table of contents
 286          */
 287         private $mEnableTOC = false;
 288
 289         /**
 290          * @var string|null The URL to send in a <link> element with rel=license
 291          */
 292         private $copyrightUrl;
 293
 294         /** @var array Profiling data */
 295         private $limitReportJSData = [];
 296
 297         /** @var array Map Title to Content */
 298         private $contentOverrides = [];
 299
 300         /** @var callable[] */
 301         private $contentOverrideCallbacks = [];
 302
 303         /**
 304          * Link: header contents
 305          */
 306         private $mLinkHeader = [];
 307
 308         /**
 309          * @var string The nonce for Content-Security-Policy
 310          */
 311         private $CSPNonce;
 312
 313         /**
 314          * Constructor for OutputPage. This should not be called directly.
 315          * Instead a new RequestContext should be created and it will implicitly create
 316          * a OutputPage tied to that context.
 317          * @param IContextSource $context
 318          */
 319         function __construct( IContextSource $context ) {
 320                 $this->setContext( $context );
 321         }
 322
 323         /**
 324          * Redirect to $url rather than displaying the normal page
 325          *
 326          * @param string $url
 327          * @param string $responsecode HTTP status code
 328          */
 329         public function redirect( $url, $responsecode = '302' ) {
 330                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 331                 $this->mRedirect = str_replace( "\n", '', $url );
 332                 $this->mRedirectCode = $responsecode;
 333         }
 334
 335         /**
 336          * Get the URL to redirect to, or an empty string if not redirect URL set
 337          *
 338          * @return string
 339          */
 340         public function getRedirect() {
 341                 return $this->mRedirect;
 342         }
 343
 344         /**
 345          * Set the copyright URL to send with the output.
 346          * Empty string to omit, null to reset.
 347          *
 348          * @since 1.26
 349          *
 350          * @param string|null $url
 351          */
 352         public function setCopyrightUrl( $url ) {
 353                 $this->copyrightUrl = $url;
 354         }
 355
 356         /**
 357          * Set the HTTP status code to send with the output.
 358          *
 359          * @param int $statusCode
 360          */
 361         public function setStatusCode( $statusCode ) {
 362                 $this->mStatusCode = $statusCode;
 363         }
 364
 365         /**
 366          * Add a new "<meta>" tag
 367          * To add an http-equiv meta tag, precede the name with "http:"
 368          *
 369          * @param string $name Name of the meta tag
 370          * @param string $val Value of the meta tag
 371          */
 372         function addMeta( $name, $val ) {
 373                 array_push( $this->mMetatags, [ $name, $val ] );
 374         }
 375
 376         /**
 377          * Returns the current <meta> tags
 378          *
 379          * @since 1.25
 380          * @return array
 381          */
 382         public function getMetaTags() {
 383                 return $this->mMetatags;
 384         }
 385
 386         /**
 387          * Add a new \<link\> tag to the page header.
 388          *
 389          * Note: use setCanonicalUrl() for rel=canonical.
 390          *
 391          * @param array $linkarr Associative array of attributes.
 392          */
 393         function addLink( array $linkarr ) {
 394                 array_push( $this->mLinktags, $linkarr );
 395         }
 396
 397         /**
 398          * Returns the current <link> tags
 399          *
 400          * @since 1.25
 401          * @return array
 402          */
 403         public function getLinkTags() {
 404                 return $this->mLinktags;
 405         }
 406
 407         /**
 408          * Add a new \<link\> with "rel" attribute set to "meta"
 409          *
 410          * @param array $linkarr Associative array mapping attribute names to their
 411          *                 values, both keys and values will be escaped, and the
 412          *                 "rel" attribute will be automatically added
 413          */
 414         function addMetadataLink( array $linkarr ) {
 415                 $linkarr['rel'] = $this->getMetadataAttribute();
 416                 $this->addLink( $linkarr );
 417         }
 418
 419         /**
 420          * Set the URL to be used for the <link rel=canonical>. This should be used
 421          * in preference to addLink(), to avoid duplicate link tags.
 422          * @param string $url
 423          */
 424         function setCanonicalUrl( $url ) {
 425                 $this->mCanonicalUrl = $url;
 426         }
 427
 428         /**
 429          * Returns the URL to be used for the <link rel=canonical> if
 430          * one is set.
 431          *
 432          * @since 1.25
 433          * @return bool|string
 434          */
 435         public function getCanonicalUrl() {
 436                 return $this->mCanonicalUrl;
 437         }
 438
 439         /**
 440          * Get the value of the "rel" attribute for metadata links
 441          *
 442          * @return string
 443          */
 444         public function getMetadataAttribute() {
 445                 # note: buggy CC software only reads first "meta" link
 446                 static $haveMeta = false;
 447                 if ( $haveMeta ) {
 448                         return 'alternate meta';
 449                 } else {
 450                         $haveMeta = true;
 451                         return 'meta';
 452                 }
 453         }
 454
 455         /**
 456          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 457          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 458          * if possible.
 459          *
 460          * @param string $script Raw HTML
 461          */
 462         function addScript( $script ) {
 463                 $this->mScripts .= $script;
 464         }
 465
 466         /**
 467          * Add a JavaScript file to be loaded as `<script>` on this page.
 468          *
 469          * Internal use only. Use OutputPage::addModules() if possible.
 470          *
 471          * @param string $file URL to file (absolute path, protocol-relative, or full url)
 472          * @param string|null $unused Previously used to change the cache-busting query parameter
 473          */
 474         public function addScriptFile( $file, $unused = null ) {
 475                 if ( substr( $file, 0, 1 ) !== '/' && !preg_match( '#^[a-z]*://#i', $file ) ) {
 476                         // This is not an absolute path, protocol-relative url, or full scheme url,
 477                         // presumed to be an old call intended to include a file from /w/skins/common,
 478                         // which doesn't exist anymore as of MediaWiki 1.24 per T71277. Ignore.
 479                         wfDeprecated( __METHOD__, '1.24' );
 480                         return;
 481                 }
 482                 $this->addScript( Html::linkedScript( $file, $this->getCSPNonce() ) );
 483         }
 484
 485         /**
 486          * Add a self-contained script tag with the given contents
 487          * Internal use only. Use OutputPage::addModules() if possible.
 488          *
 489          * @param string $script JavaScript text, no script tags
 490          */
 491         public function addInlineScript( $script ) {
 492                 $this->mScripts .= Html::inlineScript( "\n$script\n", $this->getCSPNonce() ) . "\n";
 493         }
 494
 495         /**
 496          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 497          * which are no longer registered (eg a page is cached before an extension is disabled)
 498          * @param array $modules
 499          * @param string|null $position Unused
 500          * @param string $type
 501          * @return array
 502          */
 503         protected function filterModules( array $modules, $position = null,
 504                 $type = ResourceLoaderModule::TYPE_COMBINED
 505         ) {
 506                 $resourceLoader = $this->getResourceLoader();
 507                 $filteredModules = [];
 508                 foreach ( $modules as $val ) {
 509                         $module = $resourceLoader->getModule( $val );
 510                         if ( $module instanceof ResourceLoaderModule
 511                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 512                         ) {
 513                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 514                                         $this->warnModuleTargetFilter( $module->getName() );
 515                                         continue;
 516                                 }
 517                                 $filteredModules[] = $val;
 518                         }
 519                 }
 520                 return $filteredModules;
 521         }
 522
 523         private function warnModuleTargetFilter( $moduleName ) {
 524                 static $warnings = [];
 525                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 526                         return;
 527                 }
 528                 $warnings[$this->mTarget][$moduleName] = true;
 529                 $this->getResourceLoader()->getLogger()->debug(
 530                         'Module "{module}" not loadable on target "{target}".',
 531                         [
 532                                 'module' => $moduleName,
 533                                 'target' => $this->mTarget,
 534                         ]
 535                 );
 536         }
 537
 538         /**
 539          * Get the list of modules to include on this page
 540          *
 541          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 542          * @param string|null $position Unused
 543          * @param string $param
 544          * @param string $type
 545          * @return array Array of module names
 546          */
 547         public function getModules( $filter = false, $position = null, $param = 'mModules',
 548                 $type = ResourceLoaderModule::TYPE_COMBINED
 549         ) {
 550                 $modules = array_values( array_unique( $this->$param ) );
 551                 return $filter
 552                         ? $this->filterModules( $modules, null, $type )
 553                         : $modules;
 554         }
 555
 556         /**
 557          * Load one or more ResourceLoader modules on this page.
 558          *
 559          * @param string|array $modules Module name (string) or array of module names
 560          */
 561         public function addModules( $modules ) {
 562                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 563         }
 564
 565         /**
 566          * Get the list of script-only modules to load on this page.
 567          *
 568          * @param bool $filter
 569          * @param string|null $position Unused
 570          * @return array Array of module names
 571          */
 572         public function getModuleScripts( $filter = false, $position = null ) {
 573                 return $this->getModules( $filter, null, 'mModuleScripts',
 574                         ResourceLoaderModule::TYPE_SCRIPTS
 575                 );
 576         }
 577
 578         /**
 579          * Load the scripts of one or more ResourceLoader modules, on this page.
 580          *
 581          * This method exists purely to provide the legacy behaviour of loading
 582          * a module's scripts in the global scope, and without dependency resolution.
 583          * See <https://phabricator.wikimedia.org/T188689>.
 584          *
 585          * @deprecated since 1.31 Use addModules() instead.
 586          * @param string|array $modules Module name (string) or array of module names
 587          */
 588         public function addModuleScripts( $modules ) {
 589                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 590         }
 591
 592         /**
 593          * Get the list of style-only modules to load on this page.
 594          *
 595          * @param bool $filter
 596          * @param string|null $position Unused
 597          * @return array Array of module names
 598          */
 599         public function getModuleStyles( $filter = false, $position = null ) {
 600                 return $this->getModules( $filter, null, 'mModuleStyles',
 601                         ResourceLoaderModule::TYPE_STYLES
 602                 );
 603         }
 604
 605         /**
 606          * Load the styles of one or more ResourceLoader modules on this page.
 607          *
 608          * Module styles added through this function will be loaded as a stylesheet,
 609          * using a standard `<link rel=stylesheet>` HTML tag, rather than as a combined
 610          * Javascript and CSS package. Thus, they will even load when JavaScript is disabled.
 611          *
 612          * @param string|array $modules Module name (string) or array of module names
 613          */
 614         public function addModuleStyles( $modules ) {
 615                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 616         }
 617
 618         /**
 619          * @return null|string ResourceLoader target
 620          */
 621         public function getTarget() {
 622                 return $this->mTarget;
 623         }
 624
 625         /**
 626          * Sets ResourceLoader target for load.php links. If null, will be omitted
 627          *
 628          * @param string|null $target
 629          */
 630         public function setTarget( $target ) {
 631                 $this->mTarget = $target;
 632         }
 633
 634         /**
 635          * Add a mapping from a LinkTarget to a Content, for things like page preview.
 636          * @see self::addContentOverrideCallback()
 637          * @since 1.32
 638          * @param LinkTarget $target
 639          * @param Content $content
 640          */
 641         public function addContentOverride( LinkTarget $target, Content $content ) {
 642                 if ( !$this->contentOverrides ) {
 643                         // Register a callback for $this->contentOverrides on the first call
 644                         $this->addContentOverrideCallback( function ( LinkTarget $target ) {
 645                                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 646                                 return $this->contentOverrides[$key] ?? null;
 647                         } );
 648                 }
 649
 650                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 651                 $this->contentOverrides[$key] = $content;
 652         }
 653
 654         /**
 655          * Add a callback for mapping from a Title to a Content object, for things
 656          * like page preview.
 657          * @see ResourceLoaderContext::getContentOverrideCallback()
 658          * @since 1.32
 659          * @param callable $callback
 660          */
 661         public function addContentOverrideCallback( callable $callback ) {
 662                 $this->contentOverrideCallbacks[] = $callback;
 663         }
 664
 665         /**
 666          * Get an array of head items
 667          *
 668          * @return array
 669          */
 670         function getHeadItemsArray() {
 671                 return $this->mHeadItems;
 672         }
 673
 674         /**
 675          * Add or replace a head item to the output
 676          *
 677          * Whenever possible, use more specific options like ResourceLoader modules,
 678          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 679          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 680          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 681          * This would be your very LAST fallback.
 682          *
 683          * @param string $name Item name
 684          * @param string $value Raw HTML
 685          */
 686         public function addHeadItem( $name, $value ) {
 687                 $this->mHeadItems[$name] = $value;
 688         }
 689
 690         /**
 691          * Add one or more head items to the output
 692          *
 693          * @since 1.28
 694          * @param string|string[] $values Raw HTML
 695          */
 696         public function addHeadItems( $values ) {
 697                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 698         }
 699
 700         /**
 701          * Check if the header item $name is already set
 702          *
 703          * @param string $name Item name
 704          * @return bool
 705          */
 706         public function hasHeadItem( $name ) {
 707                 return isset( $this->mHeadItems[$name] );
 708         }
 709
 710         /**
 711          * Add a class to the <body> element
 712          *
 713          * @since 1.30
 714          * @param string|string[] $classes One or more classes to add
 715          */
 716         public function addBodyClasses( $classes ) {
 717                 $this->mAdditionalBodyClasses = array_merge( $this->mAdditionalBodyClasses, (array)$classes );
 718         }
 719
 720         /**
 721          * Set whether the output should only contain the body of the article,
 722          * without any skin, sidebar, etc.
 723          * Used e.g. when calling with "action=render".
 724          *
 725          * @param bool $only Whether to output only the body of the article
 726          */
 727         public function setArticleBodyOnly( $only ) {
 728                 $this->mArticleBodyOnly = $only;
 729         }
 730
 731         /**
 732          * Return whether the output will contain only the body of the article
 733          *
 734          * @return bool
 735          */
 736         public function getArticleBodyOnly() {
 737                 return $this->mArticleBodyOnly;
 738         }
 739
 740         /**
 741          * Set an additional output property
 742          * @since 1.21
 743          *
 744          * @param string $name
 745          * @param mixed $value
 746          */
 747         public function setProperty( $name, $value ) {
 748                 $this->mProperties[$name] = $value;
 749         }
 750
 751         /**
 752          * Get an additional output property
 753          * @since 1.21
 754          *
 755          * @param string $name
 756          * @return mixed Property value or null if not found
 757          */
 758         public function getProperty( $name ) {
 759                 return $this->mProperties[$name] ?? null;
 760         }
 761
 762         /**
 763          * checkLastModified tells the client to use the client-cached page if
 764          * possible. If successful, the OutputPage is disabled so that
 765          * any future call to OutputPage->output() have no effect.
 766          *
 767          * Side effect: sets mLastModified for Last-Modified header
 768          *
 769          * @param string $timestamp
 770          *
 771          * @return bool True if cache-ok headers was sent.
 772          */
 773         public function checkLastModified( $timestamp ) {
 774                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 775                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 776                         return false;
 777                 }
 778                 $config = $this->getConfig();
 779                 if ( !$config->get( 'CachePages' ) ) {
 780                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 781                         return false;
 782                 }
 783
 784                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 785                 $modifiedTimes = [
 786                         'page' => $timestamp,
 787                         'user' => $this->getUser()->getTouched(),
 788                         'epoch' => $config->get( 'CacheEpoch' )
 789                 ];
 790                 if ( $config->get( 'UseSquid' ) ) {
 791                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, $this->getCdnCacheEpoch(
 792                                 time(),
 793                                 $config->get( 'SquidMaxage' )
 794                         ) );
 795                 }
 796                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 797
 798                 $maxModified = max( $modifiedTimes );
 799                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 800
 801                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 802                 if ( $clientHeader === false ) {
 803                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 804                         return false;
 805                 }
 806
 807                 # IE sends sizes after the date like this:
 808                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 809                 # this breaks strtotime().
 810                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 811
 812                 Wikimedia\suppressWarnings(); // E_STRICT system time bitching
 813                 $clientHeaderTime = strtotime( $clientHeader );
 814                 Wikimedia\restoreWarnings();
 815                 if ( !$clientHeaderTime ) {
 816                         wfDebug( __METHOD__
 817                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 818                         return false;
 819                 }
 820                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 821
 822                 # Make debug info
 823                 $info = '';
 824                 foreach ( $modifiedTimes as $name => $value ) {
 825                         if ( $info !== '' ) {
 826                                 $info .= ', ';
 827                         }
 828                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 829                 }
 830
 831                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 832                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 833                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 834                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 835                 if ( $clientHeaderTime < $maxModified ) {
 836                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 837                         return false;
 838                 }
 839
 840                 # Not modified
 841                 # Give a 304 Not Modified response code and disable body output
 842                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 843                 ini_set( 'zlib.output_compression', 0 );
 844                 $this->getRequest()->response()->statusHeader( 304 );
 845                 $this->sendCacheControl();
 846                 $this->disable();
 847
 848                 // Don't output a compressed blob when using ob_gzhandler;
 849                 // it's technically against HTTP spec and seems to confuse
 850                 // Firefox when the response gets split over two packets.
 851                 wfClearOutputBuffers();
 852
 853                 return true;
 854         }
 855
 856         /**
 857          * @param int $reqTime Time of request (eg. now)
 858          * @param int $maxAge Cache TTL in seconds
 859          * @return int Timestamp
 860          */
 861         private function getCdnCacheEpoch( $reqTime, $maxAge ) {
 862                 // Ensure Last-Modified is never more than (wgSquidMaxage) in the past,
 863                 // because even if the wiki page content hasn't changed since, static
 864                 // resources may have changed (skin HTML, interface messages, urls, etc.)
 865                 // and must roll-over in a timely manner (T46570)
 866                 return $reqTime - $maxAge;
 867         }
 868
 869         /**
 870          * Override the last modified timestamp
 871          *
 872          * @param string $timestamp New timestamp, in a format readable by
 873          *        wfTimestamp()
 874          */
 875         public function setLastModified( $timestamp ) {
 876                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 877         }
 878
 879         /**
 880          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 881          *
 882          * @param string $policy The literal string to output as the contents of
 883          *   the meta tag.  Will be parsed according to the spec and output in
 884          *   standardized form.
 885          * @return null
 886          */
 887         public function setRobotPolicy( $policy ) {
 888                 $policy = Article::formatRobotPolicy( $policy );
 889
 890                 if ( isset( $policy['index'] ) ) {
 891                         $this->setIndexPolicy( $policy['index'] );
 892                 }
 893                 if ( isset( $policy['follow'] ) ) {
 894                         $this->setFollowPolicy( $policy['follow'] );
 895                 }
 896         }
 897
 898         /**
 899          * Set the index policy for the page, but leave the follow policy un-
 900          * touched.
 901          *
 902          * @param string $policy Either 'index' or 'noindex'.
 903          * @return null
 904          */
 905         public function setIndexPolicy( $policy ) {
 906                 $policy = trim( $policy );
 907                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 908                         $this->mIndexPolicy = $policy;
 909                 }
 910         }
 911
 912         /**
 913          * Set the follow policy for the page, but leave the index policy un-
 914          * touched.
 915          *
 916          * @param string $policy Either 'follow' or 'nofollow'.
 917          * @return null
 918          */
 919         public function setFollowPolicy( $policy ) {
 920                 $policy = trim( $policy );
 921                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 922                         $this->mFollowPolicy = $policy;
 923                 }
 924         }
 925
 926         /**
 927          * Set the new value of the "action text", this will be added to the
 928          * "HTML title", separated from it with " - ".
 929          *
 930          * @param string $text New value of the "action text"
 931          */
 932         public function setPageTitleActionText( $text ) {
 933                 $this->mPageTitleActionText = $text;
 934         }
 935
 936         /**
 937          * Get the value of the "action text"
 938          *
 939          * @return string
 940          */
 941         public function getPageTitleActionText() {
 942                 return $this->mPageTitleActionText;
 943         }
 944
 945         /**
 946          * "HTML title" means the contents of "<title>".
 947          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 948          *
 949          * @param string|Message $name
 950          */
 951         public function setHTMLTitle( $name ) {
 952                 if ( $name instanceof Message ) {
 953                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 954                 } else {
 955                         $this->mHTMLtitle = $name;
 956                 }
 957         }
 958
 959         /**
 960          * Return the "HTML title", i.e. the content of the "<title>" tag.
 961          *
 962          * @return string
 963          */
 964         public function getHTMLTitle() {
 965                 return $this->mHTMLtitle;
 966         }
 967
 968         /**
 969          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 970          *
 971          * @param Title $t
 972          */
 973         public function setRedirectedFrom( $t ) {
 974                 $this->mRedirectedFrom = $t;
 975         }
 976
 977         /**
 978          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 979          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 980          * but not bad tags like \<script\>. This function automatically sets
 981          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 982          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 983          * good tags like \<i\> will be dropped entirely.
 984          *
 985          * @param string|Message $name
 986          */
 987         public function setPageTitle( $name ) {
 988                 if ( $name instanceof Message ) {
 989                         $name = $name->setContext( $this->getContext() )->text();
 990                 }
 991
 992                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 993                 # but leave "<i>foobar</i>" alone
 994                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 995                 $this->mPagetitle = $nameWithTags;
 996
 997                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 998                 $this->setHTMLTitle(
 999                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
1000                                 ->inContentLanguage()
1001                 );
1002         }
1003
1004         /**
1005          * Return the "page title", i.e. the content of the \<h1\> tag.
1006          *
1007          * @return string
1008          */
1009         public function getPageTitle() {
1010                 return $this->mPagetitle;
1011         }
1012
1013         /**
1014          * Set the Title object to use
1015          *
1016          * @param Title $t
1017          */
1018         public function setTitle( Title $t ) {
1019                 $this->getContext()->setTitle( $t );
1020         }
1021
1022         /**
1023          * Replace the subtitle with $str
1024          *
1025          * @param string|Message $str New value of the subtitle. String should be safe HTML.
1026          */
1027         public function setSubtitle( $str ) {
1028                 $this->clearSubtitle();
1029                 $this->addSubtitle( $str );
1030         }
1031
1032         /**
1033          * Add $str to the subtitle
1034          *
1035          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
1036          */
1037         public function addSubtitle( $str ) {
1038                 if ( $str instanceof Message ) {
1039                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
1040                 } else {
1041                         $this->mSubtitle[] = $str;
1042                 }
1043         }
1044
1045         /**
1046          * Build message object for a subtitle containing a backlink to a page
1047          *
1048          * @param Title $title Title to link to
1049          * @param array $query Array of additional parameters to include in the link
1050          * @return Message
1051          * @since 1.25
1052          */
1053         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1054                 if ( $title->isRedirect() ) {
1055                         $query['redirect'] = 'no';
1056                 }
1057                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1058                 return wfMessage( 'backlinksubtitle' )
1059                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1060         }
1061
1062         /**
1063          * Add a subtitle containing a backlink to a page
1064          *
1065          * @param Title $title Title to link to
1066          * @param array $query Array of additional parameters to include in the link
1067          */
1068         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1069                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1070         }
1071
1072         /**
1073          * Clear the subtitles
1074          */
1075         public function clearSubtitle() {
1076                 $this->mSubtitle = [];
1077         }
1078
1079         /**
1080          * Get the subtitle
1081          *
1082          * @return string
1083          */
1084         public function getSubtitle() {
1085                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1086         }
1087
1088         /**
1089          * Set the page as printable, i.e. it'll be displayed with all
1090          * print styles included
1091          */
1092         public function setPrintable() {
1093                 $this->mPrintable = true;
1094         }
1095
1096         /**
1097          * Return whether the page is "printable"
1098          *
1099          * @return bool
1100          */
1101         public function isPrintable() {
1102                 return $this->mPrintable;
1103         }
1104
1105         /**
1106          * Disable output completely, i.e. calling output() will have no effect
1107          */
1108         public function disable() {
1109                 $this->mDoNothing = true;
1110         }
1111
1112         /**
1113          * Return whether the output will be completely disabled
1114          *
1115          * @return bool
1116          */
1117         public function isDisabled() {
1118                 return $this->mDoNothing;
1119         }
1120
1121         /**
1122          * Show an "add new section" link?
1123          *
1124          * @return bool
1125          */
1126         public function showNewSectionLink() {
1127                 return $this->mNewSectionLink;
1128         }
1129
1130         /**
1131          * Forcibly hide the new section link?
1132          *
1133          * @return bool
1134          */
1135         public function forceHideNewSectionLink() {
1136                 return $this->mHideNewSectionLink;
1137         }
1138
1139         /**
1140          * Add or remove feed links in the page header
1141          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1142          * for the new version
1143          * @see addFeedLink()
1144          *
1145          * @param bool $show True: add default feeds, false: remove all feeds
1146          */
1147         public function setSyndicated( $show = true ) {
1148                 if ( $show ) {
1149                         $this->setFeedAppendQuery( false );
1150                 } else {
1151                         $this->mFeedLinks = [];
1152                 }
1153         }
1154
1155         /**
1156          * Add default feeds to the page header
1157          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1158          * for the new version
1159          * @see addFeedLink()
1160          *
1161          * @param string $val Query to append to feed links or false to output
1162          *        default links
1163          */
1164         public function setFeedAppendQuery( $val ) {
1165                 $this->mFeedLinks = [];
1166
1167                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1168                         $query = "feed=$type";
1169                         if ( is_string( $val ) ) {
1170                                 $query .= '&' . $val;
1171                         }
1172                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1173                 }
1174         }
1175
1176         /**
1177          * Add a feed link to the page header
1178          *
1179          * @param string $format Feed type, should be a key of $wgFeedClasses
1180          * @param string $href URL
1181          */
1182         public function addFeedLink( $format, $href ) {
1183                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1184                         $this->mFeedLinks[$format] = $href;
1185                 }
1186         }
1187
1188         /**
1189          * Should we output feed links for this page?
1190          * @return bool
1191          */
1192         public function isSyndicated() {
1193                 return count( $this->mFeedLinks ) > 0;
1194         }
1195
1196         /**
1197          * Return URLs for each supported syndication format for this page.
1198          * @return array Associating format keys with URLs
1199          */
1200         public function getSyndicationLinks() {
1201                 return $this->mFeedLinks;
1202         }
1203
1204         /**
1205          * Will currently always return null
1206          *
1207          * @return null
1208          */
1209         public function getFeedAppendQuery() {
1210                 return $this->mFeedLinksAppendQuery;
1211         }
1212
1213         /**
1214          * Set whether the displayed content is related to the source of the
1215          * corresponding article on the wiki
1216          * Setting true will cause the change "article related" toggle to true
1217          *
1218          * @param bool $v
1219          */
1220         public function setArticleFlag( $v ) {
1221                 $this->mIsarticle = $v;
1222                 if ( $v ) {
1223                         $this->mIsArticleRelated = $v;
1224                 }
1225         }
1226
1227         /**
1228          * Return whether the content displayed page is related to the source of
1229          * the corresponding article on the wiki
1230          *
1231          * @return bool
1232          */
1233         public function isArticle() {
1234                 return $this->mIsarticle;
1235         }
1236
1237         /**
1238          * Set whether this page is related an article on the wiki
1239          * Setting false will cause the change of "article flag" toggle to false
1240          *
1241          * @param bool $v
1242          */
1243         public function setArticleRelated( $v ) {
1244                 $this->mIsArticleRelated = $v;
1245                 if ( !$v ) {
1246                         $this->mIsarticle = false;
1247                 }
1248         }
1249
1250         /**
1251          * Return whether this page is related an article on the wiki
1252          *
1253          * @return bool
1254          */
1255         public function isArticleRelated() {
1256                 return $this->mIsArticleRelated;
1257         }
1258
1259         /**
1260          * Add new language links
1261          *
1262          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1263          *                               (e.g. 'fr:Test page')
1264          */
1265         public function addLanguageLinks( array $newLinkArray ) {
1266                 $this->mLanguageLinks += $newLinkArray;
1267         }
1268
1269         /**
1270          * Reset the language links and add new language links
1271          *
1272          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1273          *                               (e.g. 'fr:Test page')
1274          */
1275         public function setLanguageLinks( array $newLinkArray ) {
1276                 $this->mLanguageLinks = $newLinkArray;
1277         }
1278
1279         /**
1280          * Get the list of language links
1281          *
1282          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1283          */
1284         public function getLanguageLinks() {
1285                 return $this->mLanguageLinks;
1286         }
1287
1288         /**
1289          * Add an array of categories, with names in the keys
1290          *
1291          * @param array $categories Mapping category name => sort key
1292          */
1293         public function addCategoryLinks( array $categories ) {
1294                 global $wgContLang;
1295
1296                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1297                         return;
1298                 }
1299
1300                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1301
1302                 # Set all the values to 'normal'.
1303                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1304
1305                 # Mark hidden categories
1306                 foreach ( $res as $row ) {
1307                         if ( isset( $row->pp_value ) ) {
1308                                 $categories[$row->page_title] = 'hidden';
1309                         }
1310                 }
1311
1312                 // Avoid PHP 7.1 warning of passing $this by reference
1313                 $outputPage = $this;
1314                 # Add the remaining categories to the skin
1315                 if ( Hooks::run(
1316                         'OutputPageMakeCategoryLinks',
1317                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1318                 ) {
1319                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1320                         foreach ( $categories as $category => $type ) {
1321                                 // array keys will cast numeric category names to ints, so cast back to string
1322                                 $category = (string)$category;
1323                                 $origcategory = $category;
1324                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1325                                 if ( !$title ) {
1326                                         continue;
1327                                 }
1328                                 $wgContLang->findVariantLink( $category, $title, true );
1329                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1330                                         continue;
1331                                 }
1332                                 $text = $wgContLang->convertHtml( $title->getText() );
1333                                 $this->mCategories[$type][] = $title->getText();
1334                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1335                         }
1336                 }
1337         }
1338
1339         /**
1340          * @param array $categories
1341          * @return bool|IResultWrapper
1342          */
1343         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1344                 # Add the links to a LinkBatch
1345                 $arr = [ NS_CATEGORY => $categories ];
1346                 $lb = new LinkBatch;
1347                 $lb->setArray( $arr );
1348
1349                 # Fetch existence plus the hiddencat property
1350                 $dbr = wfGetDB( DB_REPLICA );
1351                 $fields = array_merge(
1352                         LinkCache::getSelectFields(),
1353                         [ 'page_namespace', 'page_title', 'pp_value' ]
1354                 );
1355
1356                 $res = $dbr->select( [ 'page', 'page_props' ],
1357                         $fields,
1358                         $lb->constructSet( 'page', $dbr ),
1359                         __METHOD__,
1360                         [],
1361                         [ 'page_props' => [ 'LEFT JOIN', [
1362                                 'pp_propname' => 'hiddencat',
1363                                 'pp_page = page_id'
1364                         ] ] ]
1365                 );
1366
1367                 # Add the results to the link cache
1368                 $linkCache = MediaWikiServices::getInstance()->getLinkCache();
1369                 $lb->addResultToCache( $linkCache, $res );
1370
1371                 return $res;
1372         }
1373
1374         /**
1375          * Reset the category links (but not the category list) and add $categories
1376          *
1377          * @param array $categories Mapping category name => sort key
1378          */
1379         public function setCategoryLinks( array $categories ) {
1380                 $this->mCategoryLinks = [];
1381                 $this->addCategoryLinks( $categories );
1382         }
1383
1384         /**
1385          * Get the list of category links, in a 2-D array with the following format:
1386          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1387          * hidden categories) and $link a HTML fragment with a link to the category
1388          * page
1389          *
1390          * @return array
1391          */
1392         public function getCategoryLinks() {
1393                 return $this->mCategoryLinks;
1394         }
1395
1396         /**
1397          * Get the list of category names this page belongs to.
1398          *
1399          * @param string $type The type of categories which should be returned. Possible values:
1400          *  * all: all categories of all types
1401          *  * hidden: only the hidden categories
1402          *  * normal: all categories, except hidden categories
1403          * @return array Array of strings
1404          */
1405         public function getCategories( $type = 'all' ) {
1406                 if ( $type === 'all' ) {
1407                         $allCategories = [];
1408                         foreach ( $this->mCategories as $categories ) {
1409                                 $allCategories = array_merge( $allCategories, $categories );
1410                         }
1411                         return $allCategories;
1412                 }
1413                 if ( !isset( $this->mCategories[$type] ) ) {
1414                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1415                 }
1416                 return $this->mCategories[$type];
1417         }
1418
1419         /**
1420          * Add an array of indicators, with their identifiers as array
1421          * keys and HTML contents as values.
1422          *
1423          * In case of duplicate keys, existing values are overwritten.
1424          *
1425          * @param array $indicators
1426          * @since 1.25
1427          */
1428         public function setIndicators( array $indicators ) {
1429                 $this->mIndicators = $indicators + $this->mIndicators;
1430                 // Keep ordered by key
1431                 ksort( $this->mIndicators );
1432         }
1433
1434         /**
1435          * Get the indicators associated with this page.
1436          *
1437          * The array will be internally ordered by item keys.
1438          *
1439          * @return array Keys: identifiers, values: HTML contents
1440          * @since 1.25
1441          */
1442         public function getIndicators() {
1443                 return $this->mIndicators;
1444         }
1445
1446         /**
1447          * Adds help link with an icon via page indicators.
1448          * Link target can be overridden by a local message containing a wikilink:
1449          * the message key is: lowercase action or special page name + '-helppage'.
1450          * @param string $to Target MediaWiki.org page title or encoded URL.
1451          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1452          * @since 1.25
1453          */
1454         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1455                 $this->addModuleStyles( 'mediawiki.helplink' );
1456                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1457
1458                 if ( $overrideBaseUrl ) {
1459                         $helpUrl = $to;
1460                 } else {
1461                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1462                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1463                 }
1464
1465                 $link = Html::rawElement(
1466                         'a',
1467                         [
1468                                 'href' => $helpUrl,
1469                                 'target' => '_blank',
1470                                 'class' => 'mw-helplink',
1471                         ],
1472                         $text
1473                 );
1474
1475                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1476         }
1477
1478         /**
1479          * Do not allow scripts which can be modified by wiki users to load on this page;
1480          * only allow scripts bundled with, or generated by, the software.
1481          * Site-wide styles are controlled by a config setting, since they can be
1482          * used to create a custom skin/theme, but not user-specific ones.
1483          *
1484          * @todo this should be given a more accurate name
1485          */
1486         public function disallowUserJs() {
1487                 $this->reduceAllowedModules(
1488                         ResourceLoaderModule::TYPE_SCRIPTS,
1489                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1490                 );
1491
1492                 // Site-wide styles are controlled by a config setting, see T73621
1493                 // for background on why. User styles are never allowed.
1494                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1495                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1496                 } else {
1497                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1498                 }
1499                 $this->reduceAllowedModules(
1500                         ResourceLoaderModule::TYPE_STYLES,
1501                         $styleOrigin
1502                 );
1503         }
1504
1505         /**
1506          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1507          * @see ResourceLoaderModule::$origin
1508          * @param string $type ResourceLoaderModule TYPE_ constant
1509          * @return int ResourceLoaderModule ORIGIN_ class constant
1510          */
1511         public function getAllowedModules( $type ) {
1512                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1513                         return min( array_values( $this->mAllowedModules ) );
1514                 } else {
1515                         return $this->mAllowedModules[$type] ?? ResourceLoaderModule::ORIGIN_ALL;
1516                 }
1517         }
1518
1519         /**
1520          * Limit the highest level of CSS/JS untrustworthiness allowed.
1521          *
1522          * If passed the same or a higher level than the current level of untrustworthiness set, the
1523          * level will remain unchanged.
1524          *
1525          * @param string $type
1526          * @param int $level ResourceLoaderModule class constant
1527          */
1528         public function reduceAllowedModules( $type, $level ) {
1529                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1530         }
1531
1532         /**
1533          * Prepend $text to the body HTML
1534          *
1535          * @param string $text HTML
1536          */
1537         public function prependHTML( $text ) {
1538                 $this->mBodytext = $text . $this->mBodytext;
1539         }
1540
1541         /**
1542          * Append $text to the body HTML
1543          *
1544          * @param string $text HTML
1545          */
1546         public function addHTML( $text ) {
1547                 $this->mBodytext .= $text;
1548         }
1549
1550         /**
1551          * Shortcut for adding an Html::element via addHTML.
1552          *
1553          * @since 1.19
1554          *
1555          * @param string $element
1556          * @param array $attribs
1557          * @param string $contents
1558          */
1559         public function addElement( $element, array $attribs = [], $contents = '' ) {
1560                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1561         }
1562
1563         /**
1564          * Clear the body HTML
1565          */
1566         public function clearHTML() {
1567                 $this->mBodytext = '';
1568         }
1569
1570         /**
1571          * Get the body HTML
1572          *
1573          * @return string HTML
1574          */
1575         public function getHTML() {
1576                 return $this->mBodytext;
1577         }
1578
1579         /**
1580          * Get/set the ParserOptions object to use for wikitext parsing
1581          *
1582          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1583          *   current ParserOption object. This parameter is deprecated since 1.31.
1584          * @return ParserOptions
1585          */
1586         public function parserOptions( $options = null ) {
1587                 if ( $options !== null ) {
1588                         wfDeprecated( __METHOD__ . ' with non-null $options', '1.31' );
1589                 }
1590
1591                 if ( $options !== null && !empty( $options->isBogus ) ) {
1592                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1593                         // been changed somehow, and keep it if so.
1594                         $anonPO = ParserOptions::newFromAnon();
1595                         $anonPO->setAllowUnsafeRawHtml( false );
1596                         if ( !$options->matches( $anonPO ) ) {
1597                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1598                                 $options->isBogus = false;
1599                         }
1600                 }
1601
1602                 if ( !$this->mParserOptions ) {
1603                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1604                                 // $wgUser isn't unstubbable yet, so don't try to get a
1605                                 // ParserOptions for it. And don't cache this ParserOptions
1606                                 // either.
1607                                 $po = ParserOptions::newFromAnon();
1608                                 $po->setAllowUnsafeRawHtml( false );
1609                                 $po->isBogus = true;
1610                                 if ( $options !== null ) {
1611                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1612                                 }
1613                                 return $po;
1614                         }
1615
1616                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1617                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1618                 }
1619
1620                 if ( $options !== null && !empty( $options->isBogus ) ) {
1621                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1622                         // thing.
1623                         return wfSetVar( $this->mParserOptions, null, true );
1624                 } else {
1625                         return wfSetVar( $this->mParserOptions, $options );
1626                 }
1627         }
1628
1629         /**
1630          * Set the revision ID which will be seen by the wiki text parser
1631          * for things such as embedded {{REVISIONID}} variable use.
1632          *
1633          * @param int|null $revid An positive integer, or null
1634          * @return mixed Previous value
1635          */
1636         public function setRevisionId( $revid ) {
1637                 $val = is_null( $revid ) ? null : intval( $revid );
1638                 return wfSetVar( $this->mRevisionId, $val );
1639         }
1640
1641         /**
1642          * Get the displayed revision ID
1643          *
1644          * @return int
1645          */
1646         public function getRevisionId() {
1647                 return $this->mRevisionId;
1648         }
1649
1650         /**
1651          * Set the timestamp of the revision which will be displayed. This is used
1652          * to avoid a extra DB call in Skin::lastModified().
1653          *
1654          * @param string|null $timestamp
1655          * @return mixed Previous value
1656          */
1657         public function setRevisionTimestamp( $timestamp ) {
1658                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1659         }
1660
1661         /**
1662          * Get the timestamp of displayed revision.
1663          * This will be null if not filled by setRevisionTimestamp().
1664          *
1665          * @return string|null
1666          */
1667         public function getRevisionTimestamp() {
1668                 return $this->mRevisionTimestamp;
1669         }
1670
1671         /**
1672          * Set the displayed file version
1673          *
1674          * @param File|bool $file
1675          * @return mixed Previous value
1676          */
1677         public function setFileVersion( $file ) {
1678                 $val = null;
1679                 if ( $file instanceof File && $file->exists() ) {
1680                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1681                 }
1682                 return wfSetVar( $this->mFileVersion, $val, true );
1683         }
1684
1685         /**
1686          * Get the displayed file version
1687          *
1688          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1689          */
1690         public function getFileVersion() {
1691                 return $this->mFileVersion;
1692         }
1693
1694         /**
1695          * Get the templates used on this page
1696          *
1697          * @return array (namespace => dbKey => revId)
1698          * @since 1.18
1699          */
1700         public function getTemplateIds() {
1701                 return $this->mTemplateIds;
1702         }
1703
1704         /**
1705          * Get the files used on this page
1706          *
1707          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1708          * @since 1.18
1709          */
1710         public function getFileSearchOptions() {
1711                 return $this->mImageTimeKeys;
1712         }
1713
1714         /**
1715          * Convert wikitext to HTML and add it to the buffer
1716          * Default assumes that the current page title will be used.
1717          *
1718          * @param string $text
1719          * @param bool $linestart Is this the start of a line?
1720          * @param bool $interface Is this text in the user interface language?
1721          * @throws MWException
1722          */
1723         public function addWikiText( $text, $linestart = true, $interface = true ) {
1724                 $title = $this->getTitle(); // Work around E_STRICT
1725                 if ( !$title ) {
1726                         throw new MWException( 'Title is null' );
1727                 }
1728                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1729         }
1730
1731         /**
1732          * Add wikitext with a custom Title object
1733          *
1734          * @param string $text Wikitext
1735          * @param Title &$title
1736          * @param bool $linestart Is this the start of a line?
1737          */
1738         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1739                 $this->addWikiTextTitle( $text, $title, $linestart );
1740         }
1741
1742         /**
1743          * Add wikitext with a custom Title object and tidy enabled.
1744          *
1745          * @param string $text Wikitext
1746          * @param Title &$title
1747          * @param bool $linestart Is this the start of a line?
1748          */
1749         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1750                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1751         }
1752
1753         /**
1754          * Add wikitext with tidy enabled
1755          *
1756          * @param string $text Wikitext
1757          * @param bool $linestart Is this the start of a line?
1758          */
1759         public function addWikiTextTidy( $text, $linestart = true ) {
1760                 $title = $this->getTitle();
1761                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1762         }
1763
1764         /**
1765          * Add wikitext with a custom Title object
1766          *
1767          * @param string $text Wikitext
1768          * @param Title $title
1769          * @param bool $linestart Is this the start of a line?
1770          * @param bool $tidy Whether to use tidy
1771          * @param bool $interface Whether it is an interface message
1772          *   (for example disables conversion)
1773          */
1774         public function addWikiTextTitle( $text, Title $title, $linestart,
1775                 $tidy = false, $interface = false
1776         ) {
1777                 global $wgParser;
1778
1779                 $popts = $this->parserOptions();
1780                 $oldTidy = $popts->setTidy( $tidy );
1781                 $popts->setInterfaceMessage( (bool)$interface );
1782
1783                 $parserOutput = $wgParser->getFreshParser()->parse(
1784                         $text, $title, $popts,
1785                         $linestart, true, $this->mRevisionId
1786                 );
1787
1788                 $popts->setTidy( $oldTidy );
1789
1790                 $this->addParserOutput( $parserOutput, [
1791                         'enableSectionEditLinks' => false,
1792                 ] );
1793         }
1794
1795         /**
1796          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1797          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1798          * and so on.
1799          *
1800          * @since 1.24
1801          * @param ParserOutput $parserOutput
1802          */
1803         public function addParserOutputMetadata( $parserOutput ) {
1804                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1805                 $this->addCategoryLinks( $parserOutput->getCategories() );
1806                 $this->setIndicators( $parserOutput->getIndicators() );
1807                 $this->mNewSectionLink = $parserOutput->getNewSection();
1808                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1809
1810                 if ( !$parserOutput->isCacheable() ) {
1811                         $this->enableClientCache( false );
1812                 }
1813                 $this->mNoGallery = $parserOutput->getNoGallery();
1814                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1815                 $this->addModules( $parserOutput->getModules() );
1816                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1817                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1818                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1819                 $this->mPreventClickjacking = $this->mPreventClickjacking
1820                         || $parserOutput->preventClickjacking();
1821
1822                 // Template versioning...
1823                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1824                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1825                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1826                         } else {
1827                                 $this->mTemplateIds[$ns] = $dbks;
1828                         }
1829                 }
1830                 // File versioning...
1831                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1832                         $this->mImageTimeKeys[$dbk] = $data;
1833                 }
1834
1835                 // Hooks registered in the object
1836                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1837                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1838                         list( $hookName, $data ) = $hookInfo;
1839                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1840                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1841                         }
1842                 }
1843
1844                 // Enable OOUI if requested via ParserOutput
1845                 if ( $parserOutput->getEnableOOUI() ) {
1846                         $this->enableOOUI();
1847                 }
1848
1849                 // Include parser limit report
1850                 if ( !$this->limitReportJSData ) {
1851                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1852                 }
1853
1854                 // Link flags are ignored for now, but may in the future be
1855                 // used to mark individual language links.
1856                 $linkFlags = [];
1857                 // Avoid PHP 7.1 warning of passing $this by reference
1858                 $outputPage = $this;
1859                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1860                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1861
1862                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
1863                 // so that extensions may modify ParserOutput to toggle TOC.
1864                 // This cannot be moved to addParserOutputText because that is not
1865                 // called by EditPage for Preview.
1866                 if ( $parserOutput->getTOCHTML() ) {
1867                         $this->mEnableTOC = true;
1868                 }
1869         }
1870
1871         /**
1872          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1873          * ParserOutput object, without any other metadata.
1874          *
1875          * @since 1.24
1876          * @param ParserOutput $parserOutput
1877          * @param array $poOptions Options to ParserOutput::getText()
1878          */
1879         public function addParserOutputContent( $parserOutput, $poOptions = [] ) {
1880                 $this->addParserOutputText( $parserOutput, $poOptions );
1881
1882                 $this->addModules( $parserOutput->getModules() );
1883                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1884                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1885
1886                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1887         }
1888
1889         /**
1890          * Add the HTML associated with a ParserOutput object, without any metadata.
1891          *
1892          * @since 1.24
1893          * @param ParserOutput $parserOutput
1894          * @param array $poOptions Options to ParserOutput::getText()
1895          */
1896         public function addParserOutputText( $parserOutput, $poOptions = [] ) {
1897                 $text = $parserOutput->getText( $poOptions );
1898                 // Avoid PHP 7.1 warning of passing $this by reference
1899                 $outputPage = $this;
1900                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1901                 $this->addHTML( $text );
1902         }
1903
1904         /**
1905          * Add everything from a ParserOutput object.
1906          *
1907          * @param ParserOutput $parserOutput
1908          * @param array $poOptions Options to ParserOutput::getText()
1909          */
1910         function addParserOutput( $parserOutput, $poOptions = [] ) {
1911                 $this->addParserOutputMetadata( $parserOutput );
1912                 $this->addParserOutputText( $parserOutput, $poOptions );
1913         }
1914
1915         /**
1916          * Add the output of a QuickTemplate to the output buffer
1917          *
1918          * @param QuickTemplate &$template
1919          */
1920         public function addTemplate( &$template ) {
1921                 $this->addHTML( $template->getHTML() );
1922         }
1923
1924         /**
1925          * Parse wikitext and return the HTML.
1926          *
1927          * @param string $text
1928          * @param bool $linestart Is this the start of a line?
1929          * @param bool $interface Use interface language ($wgLang instead of
1930          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1931          *   This also disables LanguageConverter.
1932          * @param Language|null $language Target language object, will override $interface
1933          * @throws MWException
1934          * @return string HTML
1935          */
1936         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1937                 global $wgParser;
1938
1939                 if ( is_null( $this->getTitle() ) ) {
1940                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1941                 }
1942
1943                 $popts = $this->parserOptions();
1944                 if ( $interface ) {
1945                         $popts->setInterfaceMessage( true );
1946                 }
1947                 if ( $language !== null ) {
1948                         $oldLang = $popts->setTargetLanguage( $language );
1949                 }
1950
1951                 $parserOutput = $wgParser->getFreshParser()->parse(
1952                         $text, $this->getTitle(), $popts,
1953                         $linestart, true, $this->mRevisionId
1954                 );
1955
1956                 if ( $interface ) {
1957                         $popts->setInterfaceMessage( false );
1958                 }
1959                 if ( $language !== null ) {
1960                         $popts->setTargetLanguage( $oldLang );
1961                 }
1962
1963                 return $parserOutput->getText( [
1964                         'enableSectionEditLinks' => false,
1965                 ] );
1966         }
1967
1968         /**
1969          * Parse wikitext, strip paragraphs, and return the HTML.
1970          *
1971          * @param string $text
1972          * @param bool $linestart Is this the start of a line?
1973          * @param bool $interface Use interface language ($wgLang instead of
1974          *   $wgContLang) while parsing language sensitive magic
1975          *   words like GRAMMAR and PLURAL
1976          * @return string HTML
1977          */
1978         public function parseInline( $text, $linestart = true, $interface = false ) {
1979                 $parsed = $this->parse( $text, $linestart, $interface );
1980                 return Parser::stripOuterParagraph( $parsed );
1981         }
1982
1983         /**
1984          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1985          *
1986          * @param int $maxage Maximum cache time on the CDN, in seconds.
1987          */
1988         public function setCdnMaxage( $maxage ) {
1989                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1990         }
1991
1992         /**
1993          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1994          *
1995          * @param int $maxage Maximum cache time on the CDN, in seconds
1996          * @since 1.27
1997          */
1998         public function lowerCdnMaxage( $maxage ) {
1999                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
2000                 $this->setCdnMaxage( $this->mCdnMaxage );
2001         }
2002
2003         /**
2004          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
2005          *
2006          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
2007          * the TTL is higher the older the $mtime timestamp is. Essentially, the
2008          * TTL is 90% of the age of the object, subject to the min and max.
2009          *
2010          * @param string|int|float|bool|null $mtime Last-Modified timestamp
2011          * @param int $minTTL Mimimum TTL in seconds [default: 1 minute]
2012          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
2013          * @return int TTL in seconds
2014          * @since 1.28
2015          */
2016         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
2017                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
2018                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
2019
2020                 if ( $mtime === null || $mtime === false ) {
2021                         return $minTTL; // entity does not exist
2022                 }
2023
2024                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
2025                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
2026                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
2027
2028                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2029
2030                 return $adaptiveTTL;
2031         }
2032
2033         /**
2034          * Use enableClientCache(false) to force it to send nocache headers
2035          *
2036          * @param bool $state
2037          *
2038          * @return bool
2039          */
2040         public function enableClientCache( $state ) {
2041                 return wfSetVar( $this->mEnableClientCache, $state );
2042         }
2043
2044         /**
2045          * Get the list of cookies that will influence on the cache
2046          *
2047          * @return array
2048          */
2049         function getCacheVaryCookies() {
2050                 static $cookies;
2051                 if ( $cookies === null ) {
2052                         $config = $this->getConfig();
2053                         $cookies = array_merge(
2054                                 SessionManager::singleton()->getVaryCookies(),
2055                                 [
2056                                         'forceHTTPS',
2057                                 ],
2058                                 $config->get( 'CacheVaryCookies' )
2059                         );
2060                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2061                 }
2062                 return $cookies;
2063         }
2064
2065         /**
2066          * Check if the request has a cache-varying cookie header
2067          * If it does, it's very important that we don't allow public caching
2068          *
2069          * @return bool
2070          */
2071         function haveCacheVaryCookies() {
2072                 $request = $this->getRequest();
2073                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2074                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2075                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2076                                 return true;
2077                         }
2078                 }
2079                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2080                 return false;
2081         }
2082
2083         /**
2084          * Add an HTTP header that will influence on the cache
2085          *
2086          * @param string $header Header name
2087          * @param string[]|null $option Options for the Key header. See
2088          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2089          * for the list of valid options.
2090          */
2091         public function addVaryHeader( $header, array $option = null ) {
2092                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2093                         $this->mVaryHeader[$header] = [];
2094                 }
2095                 if ( !is_array( $option ) ) {
2096                         $option = [];
2097                 }
2098                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2099         }
2100
2101         /**
2102          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2103          * such as Accept-Encoding or Cookie
2104          *
2105          * @return string
2106          */
2107         public function getVaryHeader() {
2108                 // If we vary on cookies, let's make sure it's always included here too.
2109                 if ( $this->getCacheVaryCookies() ) {
2110                         $this->addVaryHeader( 'Cookie' );
2111                 }
2112
2113                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2114                         $this->addVaryHeader( $header, $options );
2115                 }
2116                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2117         }
2118
2119         /**
2120          * Add an HTTP Link: header
2121          *
2122          * @param string $header Header value
2123          */
2124         public function addLinkHeader( $header ) {
2125                 $this->mLinkHeader[] = $header;
2126         }
2127
2128         /**
2129          * Return a Link: header. Based on the values of $mLinkHeader.
2130          *
2131          * @return string
2132          */
2133         public function getLinkHeader() {
2134                 if ( !$this->mLinkHeader ) {
2135                         return false;
2136                 }
2137
2138                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2139         }
2140
2141         /**
2142          * Get a complete Key header
2143          *
2144          * @return string
2145          */
2146         public function getKeyHeader() {
2147                 $cvCookies = $this->getCacheVaryCookies();
2148
2149                 $cookiesOption = [];
2150                 foreach ( $cvCookies as $cookieName ) {
2151                         $cookiesOption[] = 'param=' . $cookieName;
2152                 }
2153                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2154
2155                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2156                         $this->addVaryHeader( $header, $options );
2157                 }
2158
2159                 $headers = [];
2160                 foreach ( $this->mVaryHeader as $header => $option ) {
2161                         $newheader = $header;
2162                         if ( is_array( $option ) && count( $option ) > 0 ) {
2163                                 $newheader .= ';' . implode( ';', $option );
2164                         }
2165                         $headers[] = $newheader;
2166                 }
2167                 $key = 'Key: ' . implode( ',', $headers );
2168
2169                 return $key;
2170         }
2171
2172         /**
2173          * T23672: Add Accept-Language to Vary and Key headers
2174          * if there's no 'variant' parameter existed in GET.
2175          *
2176          * For example:
2177          *   /w/index.php?title=Main_page should always be served; but
2178          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2179          */
2180         function addAcceptLanguage() {
2181                 $title = $this->getTitle();
2182                 if ( !$title instanceof Title ) {
2183                         return;
2184                 }
2185
2186                 $lang = $title->getPageLanguage();
2187                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2188                         $variants = $lang->getVariants();
2189                         $aloption = [];
2190                         foreach ( $variants as $variant ) {
2191                                 if ( $variant === $lang->getCode() ) {
2192                                         continue;
2193                                 } else {
2194                                         $aloption[] = 'substr=' . $variant;
2195
2196                                         // IE and some other browsers use BCP 47 standards in
2197                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2198                                         // We should handle these too.
2199                                         $variantBCP47 = LanguageCode::bcp47( $variant );
2200                                         if ( $variantBCP47 !== $variant ) {
2201                                                 $aloption[] = 'substr=' . $variantBCP47;
2202                                         }
2203                                 }
2204                         }
2205                         $this->addVaryHeader( 'Accept-Language', $aloption );
2206                 }
2207         }
2208
2209         /**
2210          * Set a flag which will cause an X-Frame-Options header appropriate for
2211          * edit pages to be sent. The header value is controlled by
2212          * $wgEditPageFrameOptions.
2213          *
2214          * This is the default for special pages. If you display a CSRF-protected
2215          * form on an ordinary view page, then you need to call this function.
2216          *
2217          * @param bool $enable
2218          */
2219         public function preventClickjacking( $enable = true ) {
2220                 $this->mPreventClickjacking = $enable;
2221         }
2222
2223         /**
2224          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2225          * This can be called from pages which do not contain any CSRF-protected
2226          * HTML form.
2227          */
2228         public function allowClickjacking() {
2229                 $this->mPreventClickjacking = false;
2230         }
2231
2232         /**
2233          * Get the prevent-clickjacking flag
2234          *
2235          * @since 1.24
2236          * @return bool
2237          */
2238         public function getPreventClickjacking() {
2239                 return $this->mPreventClickjacking;
2240         }
2241
2242         /**
2243          * Get the X-Frame-Options header value (without the name part), or false
2244          * if there isn't one. This is used by Skin to determine whether to enable
2245          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2246          *
2247          * @return string|false
2248          */
2249         public function getFrameOptions() {
2250                 $config = $this->getConfig();
2251                 if ( $config->get( 'BreakFrames' ) ) {
2252                         return 'DENY';
2253                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2254                         return $config->get( 'EditPageFrameOptions' );
2255                 }
2256                 return false;
2257         }
2258
2259         /**
2260          * Send cache control HTTP headers
2261          */
2262         public function sendCacheControl() {
2263                 $response = $this->getRequest()->response();
2264                 $config = $this->getConfig();
2265
2266                 $this->addVaryHeader( 'Cookie' );
2267                 $this->addAcceptLanguage();
2268
2269                 # don't serve compressed data to clients who can't handle it
2270                 # maintain different caches for logged-in users and non-logged in ones
2271                 $response->header( $this->getVaryHeader() );
2272
2273                 if ( $config->get( 'UseKeyHeader' ) ) {
2274                         $response->header( $this->getKeyHeader() );
2275                 }
2276
2277                 if ( $this->mEnableClientCache ) {
2278                         if (
2279                                 $config->get( 'UseSquid' ) &&
2280                                 !$response->hasCookies() &&
2281                                 !SessionManager::getGlobalSession()->isPersistent() &&
2282                                 !$this->isPrintable() &&
2283                                 $this->mCdnMaxage != 0 &&
2284                                 !$this->haveCacheVaryCookies()
2285                         ) {
2286                                 if ( $config->get( 'UseESI' ) ) {
2287                                         # We'll purge the proxy cache explicitly, but require end user agents
2288                                         # to revalidate against the proxy on each visit.
2289                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2290                                         wfDebug( __METHOD__ .
2291                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2292                                         # start with a shorter timeout for initial testing
2293                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2294                                         $response->header(
2295                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2296                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2297                                         );
2298                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2299                                 } else {
2300                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2301                                         # to revalidate against the proxy on each visit.
2302                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2303                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2304                                         wfDebug( __METHOD__ .
2305                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2306                                         # start with a shorter timeout for initial testing
2307                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2308                                         $response->header( "Cache-Control: " .
2309                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2310                                 }
2311                         } else {
2312                                 # We do want clients to cache if they can, but they *must* check for updates
2313                                 # on revisiting the page.
2314                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2315                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2316                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2317                         }
2318                         if ( $this->mLastModified ) {
2319                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2320                         }
2321                 } else {
2322                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2323
2324                         # In general, the absence of a last modified header should be enough to prevent
2325                         # the client from using its cache. We send a few other things just to make sure.
2326                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2327                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2328                         $response->header( 'Pragma: no-cache' );
2329                 }
2330         }
2331
2332         /**
2333          * Transfer styles and JavaScript modules from skin.
2334          *
2335          * @param Skin $sk to load modules for
2336          */
2337         public function loadSkinModules( $sk ) {
2338                 foreach ( $sk->getDefaultModules() as $group => $modules ) {
2339                         if ( $group === 'styles' ) {
2340                                 foreach ( $modules as $key => $moduleMembers ) {
2341                                         $this->addModuleStyles( $moduleMembers );
2342                                 }
2343                         } else {
2344                                 $this->addModules( $modules );
2345                         }
2346                 }
2347         }
2348
2349         /**
2350          * Finally, all the text has been munged and accumulated into
2351          * the object, let's actually output it:
2352          *
2353          * @param bool $return Set to true to get the result as a string rather than sending it
2354          * @return string|null
2355          * @throws Exception
2356          * @throws FatalError
2357          * @throws MWException
2358          */
2359         public function output( $return = false ) {
2360                 global $wgContLang;
2361
2362                 if ( $this->mDoNothing ) {
2363                         return $return ? '' : null;
2364                 }
2365
2366                 $response = $this->getRequest()->response();
2367                 $config = $this->getConfig();
2368
2369                 if ( $this->mRedirect != '' ) {
2370                         # Standards require redirect URLs to be absolute
2371                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2372
2373                         $redirect = $this->mRedirect;
2374                         $code = $this->mRedirectCode;
2375
2376                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2377                                 if ( $code == '301' || $code == '303' ) {
2378                                         if ( !$config->get( 'DebugRedirects' ) ) {
2379                                                 $response->statusHeader( $code );
2380                                         }
2381                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2382                                 }
2383                                 if ( $config->get( 'VaryOnXFP' ) ) {
2384                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2385                                 }
2386                                 $this->sendCacheControl();
2387
2388                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2389                                 if ( $config->get( 'DebugRedirects' ) ) {
2390                                         $url = htmlspecialchars( $redirect );
2391                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2392                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2393                                         print "</body>\n</html>\n";
2394                                 } else {
2395                                         $response->header( 'Location: ' . $redirect );
2396                                 }
2397                         }
2398
2399                         return $return ? '' : null;
2400                 } elseif ( $this->mStatusCode ) {
2401                         $response->statusHeader( $this->mStatusCode );
2402                 }
2403
2404                 # Buffer output; final headers may depend on later processing
2405                 ob_start();
2406
2407                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2408                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2409
2410                 if ( !$this->mArticleBodyOnly ) {
2411                         $sk = $this->getSkin();
2412
2413                         if ( $sk->shouldPreloadLogo() ) {
2414                                 $this->addLogoPreloadLinkHeaders();
2415                         }
2416                 }
2417
2418                 $linkHeader = $this->getLinkHeader();
2419                 if ( $linkHeader ) {
2420                         $response->header( $linkHeader );
2421                 }
2422
2423                 // Prevent framing, if requested
2424                 $frameOptions = $this->getFrameOptions();
2425                 if ( $frameOptions ) {
2426                         $response->header( "X-Frame-Options: $frameOptions" );
2427                 }
2428
2429                 ContentSecurityPolicy::sendHeaders( $this );
2430
2431                 if ( $this->mArticleBodyOnly ) {
2432                         echo $this->mBodytext;
2433                 } else {
2434                         // Enable safe mode if requested (T152169)
2435                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2436                                 $this->disallowUserJs();
2437                         }
2438
2439                         $sk = $this->getSkin();
2440                         $this->loadSkinModules( $sk );
2441
2442                         MWDebug::addModules( $this );
2443
2444                         // Avoid PHP 7.1 warning of passing $this by reference
2445                         $outputPage = $this;
2446                         // Hook that allows last minute changes to the output page, e.g.
2447                         // adding of CSS or Javascript by extensions.
2448                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2449
2450                         try {
2451                                 $sk->outputPage();
2452                         } catch ( Exception $e ) {
2453                                 ob_end_clean(); // bug T129657
2454                                 throw $e;
2455                         }
2456                 }
2457
2458                 try {
2459                         // This hook allows last minute changes to final overall output by modifying output buffer
2460                         Hooks::runWithoutAbort( 'AfterFinalPageOutput', [ $this ] );
2461                 } catch ( Exception $e ) {
2462                         ob_end_clean(); // bug T129657
2463                         throw $e;
2464                 }
2465
2466                 $this->sendCacheControl();
2467
2468                 if ( $return ) {
2469                         return ob_get_clean();
2470                 } else {
2471                         ob_end_flush();
2472                         return null;
2473                 }
2474         }
2475
2476         /**
2477          * Prepare this object to display an error page; disable caching and
2478          * indexing, clear the current text and redirect, set the page's title
2479          * and optionally an custom HTML title (content of the "<title>" tag).
2480          *
2481          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2482          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2483          *                   optional, if not passed the "<title>" attribute will be
2484          *                   based on $pageTitle
2485          */
2486         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2487                 $this->setPageTitle( $pageTitle );
2488                 if ( $htmlTitle !== false ) {
2489                         $this->setHTMLTitle( $htmlTitle );
2490                 }
2491                 $this->setRobotPolicy( 'noindex,nofollow' );
2492                 $this->setArticleRelated( false );
2493                 $this->enableClientCache( false );
2494                 $this->mRedirect = '';
2495                 $this->clearSubtitle();
2496                 $this->clearHTML();
2497         }
2498
2499         /**
2500          * Output a standard error page
2501          *
2502          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2503          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2504          * showErrorPage( 'titlemsg', $messageObject );
2505          * showErrorPage( $titleMessageObject, $messageObject );
2506          *
2507          * @param string|Message $title Message key (string) for page title, or a Message object
2508          * @param string|Message $msg Message key (string) for page text, or a Message object
2509          * @param array $params Message parameters; ignored if $msg is a Message object
2510          */
2511         public function showErrorPage( $title, $msg, $params = [] ) {
2512                 if ( !$title instanceof Message ) {
2513                         $title = $this->msg( $title );
2514                 }
2515
2516                 $this->prepareErrorPage( $title );
2517
2518                 if ( $msg instanceof Message ) {
2519                         if ( $params !== [] ) {
2520                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2521                                         . 'is discarded when the $msg argument is a Message object instead of '
2522                                         . 'a string.', E_USER_NOTICE );
2523                         }
2524                         $this->addHTML( $msg->parseAsBlock() );
2525                 } else {
2526                         $this->addWikiMsgArray( $msg, $params );
2527                 }
2528
2529                 $this->returnToMain();
2530         }
2531
2532         /**
2533          * Output a standard permission error page
2534          *
2535          * @param array $errors Error message keys or [key, param...] arrays
2536          * @param string|null $action Action that was denied or null if unknown
2537          */
2538         public function showPermissionsErrorPage( array $errors, $action = null ) {
2539                 foreach ( $errors as $key => $error ) {
2540                         $errors[$key] = (array)$error;
2541                 }
2542
2543                 // For some action (read, edit, create and upload), display a "login to do this action"
2544                 // error if all of the following conditions are met:
2545                 // 1. the user is not logged in
2546                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2547                 // 3. the error can be avoided simply by logging in
2548                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2549                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2550                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2551                         && ( User::groupHasPermission( 'user', $action )
2552                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2553                 ) {
2554                         $displayReturnto = null;
2555
2556                         # Due to T34276, if a user does not have read permissions,
2557                         # $this->getTitle() will just give Special:Badtitle, which is
2558                         # not especially useful as a returnto parameter. Use the title
2559                         # from the request instead, if there was one.
2560                         $request = $this->getRequest();
2561                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2562                         if ( $action == 'edit' ) {
2563                                 $msg = 'whitelistedittext';
2564                                 $displayReturnto = $returnto;
2565                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2566                                 $msg = 'nocreatetext';
2567                         } elseif ( $action == 'upload' ) {
2568                                 $msg = 'uploadnologintext';
2569                         } else { # Read
2570                                 $msg = 'loginreqpagetext';
2571                                 $displayReturnto = Title::newMainPage();
2572                         }
2573
2574                         $query = [];
2575
2576                         if ( $returnto ) {
2577                                 $query['returnto'] = $returnto->getPrefixedText();
2578
2579                                 if ( !$request->wasPosted() ) {
2580                                         $returntoquery = $request->getValues();
2581                                         unset( $returntoquery['title'] );
2582                                         unset( $returntoquery['returnto'] );
2583                                         unset( $returntoquery['returntoquery'] );
2584                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2585                                 }
2586                         }
2587                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2588                         $loginLink = $linkRenderer->makeKnownLink(
2589                                 SpecialPage::getTitleFor( 'Userlogin' ),
2590                                 $this->msg( 'loginreqlink' )->text(),
2591                                 [],
2592                                 $query
2593                         );
2594
2595                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2596                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2597
2598                         # Don't return to a page the user can't read otherwise
2599                         # we'll end up in a pointless loop
2600                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2601                                 $this->returnToMain( null, $displayReturnto );
2602                         }
2603                 } else {
2604                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2605                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2606                 }
2607         }
2608
2609         /**
2610          * Display an error page indicating that a given version of MediaWiki is
2611          * required to use it
2612          *
2613          * @param mixed $version The version of MediaWiki needed to use the page
2614          */
2615         public function versionRequired( $version ) {
2616                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2617
2618                 $this->addWikiMsg( 'versionrequiredtext', $version );
2619                 $this->returnToMain();
2620         }
2621
2622         /**
2623          * Format a list of error messages
2624          *
2625          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2626          * @param string|null $action Action that was denied or null if unknown
2627          * @return string The wikitext error-messages, formatted into a list.
2628          */
2629         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2630                 if ( $action == null ) {
2631                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2632                 } else {
2633                         $action_desc = $this->msg( "action-$action" )->plain();
2634                         $text = $this->msg(
2635                                 'permissionserrorstext-withaction',
2636                                 count( $errors ),
2637                                 $action_desc
2638                         )->plain() . "\n\n";
2639                 }
2640
2641                 if ( count( $errors ) > 1 ) {
2642                         $text .= '<ul class="permissions-errors">' . "\n";
2643
2644                         foreach ( $errors as $error ) {
2645                                 $text .= '<li>';
2646                                 $text .= $this->msg( ...$error )->plain();
2647                                 $text .= "</li>\n";
2648                         }
2649                         $text .= '</ul>';
2650                 } else {
2651                         $text .= "<div class=\"permissions-errors\">\n" .
2652                                         $this->msg( ...reset( $errors ) )->plain() .
2653                                         "\n</div>";
2654                 }
2655
2656                 return $text;
2657         }
2658
2659         /**
2660          * Show a warning about replica DB lag
2661          *
2662          * If the lag is higher than $wgSlaveLagCritical seconds,
2663          * then the warning is a bit more obvious. If the lag is
2664          * lower than $wgSlaveLagWarning, then no warning is shown.
2665          *
2666          * @param int $lag Slave lag
2667          */
2668         public function showLagWarning( $lag ) {
2669                 $config = $this->getConfig();
2670                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2671                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2672                         $message = $lag < $config->get( 'SlaveLagCritical' )
2673                                 ? 'lag-warn-normal'
2674                                 : 'lag-warn-high';
2675                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2676                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2677                 }
2678         }
2679
2680         public function showFatalError( $message ) {
2681                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2682
2683                 $this->addHTML( $message );
2684         }
2685
2686         public function showUnexpectedValueError( $name, $val ) {
2687                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2688         }
2689
2690         public function showFileCopyError( $old, $new ) {
2691                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2692         }
2693
2694         public function showFileRenameError( $old, $new ) {
2695                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2696         }
2697
2698         public function showFileDeleteError( $name ) {
2699                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2700         }
2701
2702         public function showFileNotFoundError( $name ) {
2703                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2704         }
2705
2706         /**
2707          * Add a "return to" link pointing to a specified title
2708          *
2709          * @param Title $title Title to link
2710          * @param array $query Query string parameters
2711          * @param string|null $text Text of the link (input is not escaped)
2712          * @param array $options Options array to pass to Linker
2713          */
2714         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2715                 $linkRenderer = MediaWikiServices::getInstance()
2716                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
2717                 $link = $this->msg( 'returnto' )->rawParams(
2718                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
2719                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2720         }
2721
2722         /**
2723          * Add a "return to" link pointing to a specified title,
2724          * or the title indicated in the request, or else the main page
2725          *
2726          * @param mixed|null $unused
2727          * @param Title|string|null $returnto Title or String to return to
2728          * @param string|null $returntoquery Query string for the return to link
2729          */
2730         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2731                 if ( $returnto == null ) {
2732                         $returnto = $this->getRequest()->getText( 'returnto' );
2733                 }
2734
2735                 if ( $returntoquery == null ) {
2736                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2737                 }
2738
2739                 if ( $returnto === '' ) {
2740                         $returnto = Title::newMainPage();
2741                 }
2742
2743                 if ( is_object( $returnto ) ) {
2744                         $titleObj = $returnto;
2745                 } else {
2746                         $titleObj = Title::newFromText( $returnto );
2747                 }
2748                 // We don't want people to return to external interwiki. That
2749                 // might potentially be used as part of a phishing scheme
2750                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
2751                         $titleObj = Title::newMainPage();
2752                 }
2753
2754                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2755         }
2756
2757         private function getRlClientContext() {
2758                 if ( !$this->rlClientContext ) {
2759                         $query = ResourceLoader::makeLoaderQuery(
2760                                 [], // modules; not relevant
2761                                 $this->getLanguage()->getCode(),
2762                                 $this->getSkin()->getSkinName(),
2763                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2764                                 null, // version; not relevant
2765                                 ResourceLoader::inDebugMode(),
2766                                 null, // only; not relevant
2767                                 $this->isPrintable(),
2768                                 $this->getRequest()->getBool( 'handheld' )
2769                         );
2770                         $this->rlClientContext = new ResourceLoaderContext(
2771                                 $this->getResourceLoader(),
2772                                 new FauxRequest( $query )
2773                         );
2774                         if ( $this->contentOverrideCallbacks ) {
2775                                 $this->rlClientContext = new DerivativeResourceLoaderContext( $this->rlClientContext );
2776                                 $this->rlClientContext->setContentOverrideCallback( function ( Title $title ) {
2777                                         foreach ( $this->contentOverrideCallbacks as $callback ) {
2778                                                 $content = call_user_func( $callback, $title );
2779                                                 if ( $content !== null ) {
2780                                                         return $content;
2781                                                 }
2782                                         }
2783                                         return null;
2784                                 } );
2785                         }
2786                 }
2787                 return $this->rlClientContext;
2788         }
2789
2790         /**
2791          * Call this to freeze the module queue and JS config and create a formatter.
2792          *
2793          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2794          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2795          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2796          * the module filters retroactively. Skins and extension hooks may also add modules until very
2797          * late in the request lifecycle.
2798          *
2799          * @return ResourceLoaderClientHtml
2800          */
2801         public function getRlClient() {
2802                 if ( !$this->rlClient ) {
2803                         $context = $this->getRlClientContext();
2804                         $rl = $this->getResourceLoader();
2805                         $this->addModules( [
2806                                 'user',
2807                                 'user.options',
2808                                 'user.tokens',
2809                         ] );
2810                         $this->addModuleStyles( [
2811                                 'site.styles',
2812                                 'noscript',
2813                                 'user.styles',
2814                         ] );
2815                         $this->getSkin()->setupSkinUserCss( $this );
2816
2817                         // Prepare exempt modules for buildExemptModules()
2818                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2819                         $exemptStates = [];
2820                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2821
2822                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2823                         // Separate user-specific batch for improved cache-hit ratio.
2824                         $userBatch = [ 'user.styles', 'user' ];
2825                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2826                         $dbr = wfGetDB( DB_REPLICA );
2827                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2828                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2829
2830                         // Filter out modules handled by buildExemptModules()
2831                         $moduleStyles = array_filter( $moduleStyles,
2832                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2833                                         $module = $rl->getModule( $name );
2834                                         if ( $module ) {
2835                                                 $group = $module->getGroup();
2836                                                 if ( isset( $exemptGroups[$group] ) ) {
2837                                                         $exemptStates[$name] = 'ready';
2838                                                         if ( !$module->isKnownEmpty( $context ) ) {
2839                                                                 // E.g. Don't output empty <styles>
2840                                                                 $exemptGroups[$group][] = $name;
2841                                                         }
2842                                                         return false;
2843                                                 }
2844                                         }
2845                                         return true;
2846                                 }
2847                         );
2848                         $this->rlExemptStyleModules = $exemptGroups;
2849
2850                         $rlClient = new ResourceLoaderClientHtml( $context, [
2851                                 'target' => $this->getTarget(),
2852                                 'nonce' => $this->getCSPNonce(),
2853                                 // When 'safemode', disallowUserJs(), or reduceAllowedModules() is used
2854                                 // to only restrict modules to ORIGIN_CORE (ie. disallow ORIGIN_USER), the list of
2855                                 // modules enqueud for loading on this page is filtered to just those.
2856                                 // However, to make sure we also apply the restriction to dynamic dependencies and
2857                                 // lazy-loaded modules at run-time on the client-side, pass 'safemode' down to the
2858                                 // StartupModule so that the client-side registry will not contain any restricted
2859                                 // modules either. (T152169, T185303)
2860                                 'safemode' => ( $this->getAllowedModules( ResourceLoaderModule::TYPE_COMBINED )
2861                                         <= ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
2862                                 ) ? '1' : null,
2863                         ] );
2864                         $rlClient->setConfig( $this->getJSVars() );
2865                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2866                         $rlClient->setModuleStyles( $moduleStyles );
2867                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2868                         $rlClient->setExemptStates( $exemptStates );
2869                         $this->rlClient = $rlClient;
2870                 }
2871                 return $this->rlClient;
2872         }
2873
2874         /**
2875          * @param Skin $sk The given Skin
2876          * @param bool $includeStyle Unused
2877          * @return string The doctype, opening "<html>", and head element.
2878          */
2879         public function headElement( Skin $sk, $includeStyle = true ) {
2880                 global $wgContLang;
2881
2882                 $userdir = $this->getLanguage()->getDir();
2883                 $sitedir = $wgContLang->getDir();
2884
2885                 $pieces = [];
2886                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2887                         $this->getRlClient()->getDocumentAttributes(),
2888                         $sk->getHtmlElementAttributes()
2889                 ) );
2890                 $pieces[] = Html::openElement( 'head' );
2891
2892                 if ( $this->getHTMLTitle() == '' ) {
2893                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2894                 }
2895
2896                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2897                         // Add <meta charset="UTF-8">
2898                         // This should be before <title> since it defines the charset used by
2899                         // text including the text inside <title>.
2900                         // The spec recommends defining XHTML5's charset using the XML declaration
2901                         // instead of meta.
2902                         // Our XML declaration is output by Html::htmlHeader.
2903                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2904                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2905                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2906                 }
2907
2908                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2909                 $pieces[] = $this->getRlClient()->getHeadHtml();
2910                 $pieces[] = $this->buildExemptModules();
2911                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2912                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2913
2914                 // Use an IE conditional comment to serve the script only to old IE
2915                 $pieces[] = '<!--[if lt IE 9]>' .
2916                         ResourceLoaderClientHtml::makeLoad(
2917                                 ResourceLoaderContext::newDummyContext(),
2918                                 [ 'html5shiv' ],
2919                                 ResourceLoaderModule::TYPE_SCRIPTS,
2920                                 [ 'sync' => true ],
2921                                 $this->getCSPNonce()
2922                         ) .
2923                         '<![endif]-->';
2924
2925                 $pieces[] = Html::closeElement( 'head' );
2926
2927                 $bodyClasses = $this->mAdditionalBodyClasses;
2928                 $bodyClasses[] = 'mediawiki';
2929
2930                 # Classes for LTR/RTL directionality support
2931                 $bodyClasses[] = $userdir;
2932                 $bodyClasses[] = "sitedir-$sitedir";
2933
2934                 $underline = $this->getUser()->getOption( 'underline' );
2935                 if ( $underline < 2 ) {
2936                         // The following classes can be used here:
2937                         // * mw-underline-always
2938                         // * mw-underline-never
2939                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2940                 }
2941
2942                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2943                         # A <body> class is probably not the best way to do this . . .
2944                         $bodyClasses[] = 'capitalize-all-nouns';
2945                 }
2946
2947                 // Parser feature migration class
2948                 // The idea is that this will eventually be removed, after the wikitext
2949                 // which requires it is cleaned up.
2950                 $bodyClasses[] = 'mw-hide-empty-elt';
2951
2952                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2953                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2954                 $bodyClasses[] =
2955                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2956
2957                 $bodyAttrs = [];
2958                 // While the implode() is not strictly needed, it's used for backwards compatibility
2959                 // (this used to be built as a string and hooks likely still expect that).
2960                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2961
2962                 // Allow skins and extensions to add body attributes they need
2963                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2964                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2965
2966                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2967
2968                 return self::combineWrappedStrings( $pieces );
2969         }
2970
2971         /**
2972          * Get a ResourceLoader object associated with this OutputPage
2973          *
2974          * @return ResourceLoader
2975          */
2976         public function getResourceLoader() {
2977                 if ( is_null( $this->mResourceLoader ) ) {
2978                         $this->mResourceLoader = new ResourceLoader(
2979                                 $this->getConfig(),
2980                                 LoggerFactory::getInstance( 'resourceloader' )
2981                         );
2982                 }
2983                 return $this->mResourceLoader;
2984         }
2985
2986         /**
2987          * Explicily load or embed modules on a page.
2988          *
2989          * @param array|string $modules One or more module names
2990          * @param string $only ResourceLoaderModule TYPE_ class constant
2991          * @param array $extraQuery [optional] Array with extra query parameters for the request
2992          * @return string|WrappedStringList HTML
2993          */
2994         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2995                 // Apply 'target' and 'origin' filters
2996                 $modules = $this->filterModules( (array)$modules, null, $only );
2997
2998                 return ResourceLoaderClientHtml::makeLoad(
2999                         $this->getRlClientContext(),
3000                         $modules,
3001                         $only,
3002                         $extraQuery,
3003                         $this->getCSPNonce()
3004                 );
3005         }
3006
3007         /**
3008          * Combine WrappedString chunks and filter out empty ones
3009          *
3010          * @param array $chunks
3011          * @return string|WrappedStringList HTML
3012          */
3013         protected static function combineWrappedStrings( array $chunks ) {
3014                 // Filter out empty values
3015                 $chunks = array_filter( $chunks, 'strlen' );
3016                 return WrappedString::join( "\n", $chunks );
3017         }
3018
3019         /**
3020          * JS stuff to put at the bottom of the `<body>`.
3021          * These are legacy scripts ($this->mScripts), and user JS.
3022          *
3023          * @return string|WrappedStringList HTML
3024          */
3025         public function getBottomScripts() {
3026                 $chunks = [];
3027                 $chunks[] = $this->getRlClient()->getBodyHtml();
3028
3029                 // Legacy non-ResourceLoader scripts
3030                 $chunks[] = $this->mScripts;
3031
3032                 if ( $this->limitReportJSData ) {
3033                         $chunks[] = ResourceLoader::makeInlineScript(
3034                                 ResourceLoader::makeConfigSetScript(
3035                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3036                                 ),
3037                                 $this->getCSPNonce()
3038                         );
3039                 }
3040
3041                 return self::combineWrappedStrings( $chunks );
3042         }
3043
3044         /**
3045          * Get the javascript config vars to include on this page
3046          *
3047          * @return array Array of javascript config vars
3048          * @since 1.23
3049          */
3050         public function getJsConfigVars() {
3051                 return $this->mJsConfigVars;
3052         }
3053
3054         /**
3055          * Add one or more variables to be set in mw.config in JavaScript
3056          *
3057          * @param string|array $keys Key or array of key/value pairs
3058          * @param mixed|null $value [optional] Value of the configuration variable
3059          */
3060         public function addJsConfigVars( $keys, $value = null ) {
3061                 if ( is_array( $keys ) ) {
3062                         foreach ( $keys as $key => $value ) {
3063                                 $this->mJsConfigVars[$key] = $value;
3064                         }
3065                         return;
3066                 }
3067
3068                 $this->mJsConfigVars[$keys] = $value;
3069         }
3070
3071         /**
3072          * Get an array containing the variables to be set in mw.config in JavaScript.
3073          *
3074          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3075          * - in other words, page-independent/site-wide variables (without state).
3076          * You will only be adding bloat to the html page and causing page caches to
3077          * have to be purged on configuration changes.
3078          * @return array
3079          */
3080         public function getJSVars() {
3081                 global $wgContLang;
3082
3083                 $curRevisionId = 0;
3084                 $articleId = 0;
3085                 $canonicalSpecialPageName = false; # T23115
3086
3087                 $title = $this->getTitle();
3088                 $ns = $title->getNamespace();
3089                 $canonicalNamespace = MWNamespace::exists( $ns )
3090                         ? MWNamespace::getCanonicalName( $ns )
3091                         : $title->getNsText();
3092
3093                 $sk = $this->getSkin();
3094                 // Get the relevant title so that AJAX features can use the correct page name
3095                 // when making API requests from certain special pages (T36972).
3096                 $relevantTitle = $sk->getRelevantTitle();
3097                 $relevantUser = $sk->getRelevantUser();
3098
3099                 if ( $ns == NS_SPECIAL ) {
3100                         list( $canonicalSpecialPageName, /*...*/ ) =
3101                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3102                 } elseif ( $this->canUseWikiPage() ) {
3103                         $wikiPage = $this->getWikiPage();
3104                         $curRevisionId = $wikiPage->getLatest();
3105                         $articleId = $wikiPage->getId();
3106                 }
3107
3108                 $lang = $title->getPageViewLanguage();
3109
3110                 // Pre-process information
3111                 $separatorTransTable = $lang->separatorTransformTable();
3112                 $separatorTransTable = $separatorTransTable ?: [];
3113                 $compactSeparatorTransTable = [
3114                         implode( "\t", array_keys( $separatorTransTable ) ),
3115                         implode( "\t", $separatorTransTable ),
3116                 ];
3117                 $digitTransTable = $lang->digitTransformTable();
3118                 $digitTransTable = $digitTransTable ?: [];
3119                 $compactDigitTransTable = [
3120                         implode( "\t", array_keys( $digitTransTable ) ),
3121                         implode( "\t", $digitTransTable ),
3122                 ];
3123
3124                 $user = $this->getUser();
3125
3126                 $vars = [
3127                         'wgCanonicalNamespace' => $canonicalNamespace,
3128                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3129                         'wgNamespaceNumber' => $title->getNamespace(),
3130                         'wgPageName' => $title->getPrefixedDBkey(),
3131                         'wgTitle' => $title->getText(),
3132                         'wgCurRevisionId' => $curRevisionId,
3133                         'wgRevisionId' => (int)$this->getRevisionId(),
3134                         'wgArticleId' => $articleId,
3135                         'wgIsArticle' => $this->isArticle(),
3136                         'wgIsRedirect' => $title->isRedirect(),
3137                         'wgAction' => Action::getActionName( $this->getContext() ),
3138                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3139                         'wgUserGroups' => $user->getEffectiveGroups(),
3140                         'wgCategories' => $this->getCategories(),
3141                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3142                         'wgPageContentLanguage' => $lang->getCode(),
3143                         'wgPageContentModel' => $title->getContentModel(),
3144                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3145                         'wgDigitTransformTable' => $compactDigitTransTable,
3146                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3147                         'wgMonthNames' => $lang->getMonthNamesArray(),
3148                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3149                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3150                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3151                         'wgRequestId' => WebRequest::getRequestId(),
3152                 ];
3153
3154                 if ( $user->isLoggedIn() ) {
3155                         $vars['wgUserId'] = $user->getId();
3156                         $vars['wgUserEditCount'] = $user->getEditCount();
3157                         $userReg = $user->getRegistration();
3158                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3159                         // Get the revision ID of the oldest new message on the user's talk
3160                         // page. This can be used for constructing new message alerts on
3161                         // the client side.
3162                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3163                 }
3164
3165                 if ( $wgContLang->hasVariants() ) {
3166                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3167                 }
3168                 // Same test as SkinTemplate
3169                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3170                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3171
3172                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3173                         && $relevantTitle->quickUserCan( 'edit', $user )
3174                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3175
3176                 foreach ( $title->getRestrictionTypes() as $type ) {
3177                         // Following keys are set in $vars:
3178                         // wgRestrictionCreate, wgRestrictionEdit, wgRestrictionMove, wgRestrictionUpload
3179                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3180                 }
3181
3182                 if ( $title->isMainPage() ) {
3183                         $vars['wgIsMainPage'] = true;
3184                 }
3185
3186                 if ( $this->mRedirectedFrom ) {
3187                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3188                 }
3189
3190                 if ( $relevantUser ) {
3191                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3192                 }
3193
3194                 // Allow extensions to add their custom variables to the mw.config map.
3195                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3196                 // page-dependant but site-wide (without state).
3197                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3198                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3199
3200                 // Merge in variables from addJsConfigVars last
3201                 return array_merge( $vars, $this->getJsConfigVars() );
3202         }
3203
3204         /**
3205          * To make it harder for someone to slip a user a fake
3206          * JavaScript or CSS preview, a random token
3207          * is associated with the login session. If it's not
3208          * passed back with the preview request, we won't render
3209          * the code.
3210          *
3211          * @return bool
3212          */
3213         public function userCanPreview() {
3214                 $request = $this->getRequest();
3215                 if (
3216                         $request->getVal( 'action' ) !== 'submit' ||
3217                         !$request->wasPosted()
3218                 ) {
3219                         return false;
3220                 }
3221
3222                 $user = $this->getUser();
3223
3224                 if ( !$user->isLoggedIn() ) {
3225                         // Anons have predictable edit tokens
3226                         return false;
3227                 }
3228                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3229                         return false;
3230                 }
3231
3232                 $title = $this->getTitle();
3233                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3234                 if ( count( $errors ) !== 0 ) {
3235                         return false;
3236                 }
3237
3238                 return true;
3239         }
3240
3241         /**
3242          * @return array Array in format "link name or number => 'link html'".
3243          */
3244         public function getHeadLinksArray() {
3245                 global $wgVersion;
3246
3247                 $tags = [];
3248                 $config = $this->getConfig();
3249
3250                 $canonicalUrl = $this->mCanonicalUrl;
3251
3252                 $tags['meta-generator'] = Html::element( 'meta', [
3253                         'name' => 'generator',
3254                         'content' => "MediaWiki $wgVersion",
3255                 ] );
3256
3257                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3258                         // Per https://w3c.github.io/webappsec-referrer-policy/#unknown-policy-values
3259                         // fallbacks should come before the primary value so we need to reverse the array.
3260                         foreach ( array_reverse( (array)$config->get( 'ReferrerPolicy' ) ) as $i => $policy ) {
3261                                 $tags["meta-referrer-$i"] = Html::element( 'meta', [
3262                                         'name' => 'referrer',
3263                                         'content' => $policy,
3264                                 ] );
3265                         }
3266                 }
3267
3268                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3269                 if ( $p !== 'index,follow' ) {
3270                         // http://www.robotstxt.org/wc/meta-user.html
3271                         // Only show if it's different from the default robots policy
3272                         $tags['meta-robots'] = Html::element( 'meta', [
3273                                 'name' => 'robots',
3274                                 'content' => $p,
3275                         ] );
3276                 }
3277
3278                 foreach ( $this->mMetatags as $tag ) {
3279                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3280                                 $a = 'http-equiv';
3281                                 $tag[0] = substr( $tag[0], 5 );
3282                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3283                                 $a = 'property';
3284                         } else {
3285                                 $a = 'name';
3286                         }
3287                         $tagName = "meta-{$tag[0]}";
3288                         if ( isset( $tags[$tagName] ) ) {
3289                                 $tagName .= $tag[1];
3290                         }
3291                         $tags[$tagName] = Html::element( 'meta',
3292                                 [
3293                                         $a => $tag[0],
3294                                         'content' => $tag[1]
3295                                 ]
3296                         );
3297                 }
3298
3299                 foreach ( $this->mLinktags as $tag ) {
3300                         $tags[] = Html::element( 'link', $tag );
3301                 }
3302
3303                 # Universal edit button
3304                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3305                         $user = $this->getUser();
3306                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3307                                 && ( $this->getTitle()->exists() ||
3308                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3309                         ) {
3310                                 // Original UniversalEditButton
3311                                 $msg = $this->msg( 'edit' )->text();
3312                                 $tags['universal-edit-button'] = Html::element( 'link', [
3313                                         'rel' => 'alternate',
3314                                         'type' => 'application/x-wiki',
3315                                         'title' => $msg,
3316                                         'href' => $this->getTitle()->getEditURL(),
3317                                 ] );
3318                                 // Alternate edit link
3319                                 $tags['alternative-edit'] = Html::element( 'link', [
3320                                         'rel' => 'edit',
3321                                         'title' => $msg,
3322                                         'href' => $this->getTitle()->getEditURL(),
3323                                 ] );
3324                         }
3325                 }
3326
3327                 # Generally the order of the favicon and apple-touch-icon links
3328                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3329                 # uses whichever one appears later in the HTML source. Make sure
3330                 # apple-touch-icon is specified first to avoid this.
3331                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3332                         $tags['apple-touch-icon'] = Html::element( 'link', [
3333                                 'rel' => 'apple-touch-icon',
3334                                 'href' => $config->get( 'AppleTouchIcon' )
3335                         ] );
3336                 }
3337
3338                 if ( $config->get( 'Favicon' ) !== false ) {
3339                         $tags['favicon'] = Html::element( 'link', [
3340                                 'rel' => 'shortcut icon',
3341                                 'href' => $config->get( 'Favicon' )
3342                         ] );
3343                 }
3344
3345                 # OpenSearch description link
3346                 $tags['opensearch'] = Html::element( 'link', [
3347                         'rel' => 'search',
3348                         'type' => 'application/opensearchdescription+xml',
3349                         'href' => wfScript( 'opensearch_desc' ),
3350                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3351                 ] );
3352
3353                 # Real Simple Discovery link, provides auto-discovery information
3354                 # for the MediaWiki API (and potentially additional custom API
3355                 # support such as WordPress or Twitter-compatible APIs for a
3356                 # blogging extension, etc)
3357                 $tags['rsd'] = Html::element( 'link', [
3358                         'rel' => 'EditURI',
3359                         'type' => 'application/rsd+xml',
3360                         // Output a protocol-relative URL here if $wgServer is protocol-relative.
3361                         // Whether RSD accepts relative or protocol-relative URLs is completely
3362                         // undocumented, though.
3363                         'href' => wfExpandUrl( wfAppendQuery(
3364                                 wfScript( 'api' ),
3365                                 [ 'action' => 'rsd' ] ),
3366                                 PROTO_RELATIVE
3367                         ),
3368                 ] );
3369
3370                 # Language variants
3371                 if ( !$config->get( 'DisableLangConversion' ) ) {
3372                         $lang = $this->getTitle()->getPageLanguage();
3373                         if ( $lang->hasVariants() ) {
3374                                 $variants = $lang->getVariants();
3375                                 foreach ( $variants as $variant ) {
3376                                         $tags["variant-$variant"] = Html::element( 'link', [
3377                                                 'rel' => 'alternate',
3378                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3379                                                 'href' => $this->getTitle()->getLocalURL(
3380                                                         [ 'variant' => $variant ] )
3381                                                 ]
3382                                         );
3383                                 }
3384                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3385                                 $tags["variant-x-default"] = Html::element( 'link', [
3386                                         'rel' => 'alternate',
3387                                         'hreflang' => 'x-default',
3388                                         'href' => $this->getTitle()->getLocalURL() ] );
3389                         }
3390                 }
3391
3392                 # Copyright
3393                 if ( $this->copyrightUrl !== null ) {
3394                         $copyright = $this->copyrightUrl;
3395                 } else {
3396                         $copyright = '';
3397                         if ( $config->get( 'RightsPage' ) ) {
3398                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3399
3400                                 if ( $copy ) {
3401                                         $copyright = $copy->getLocalURL();
3402                                 }
3403                         }
3404
3405                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3406                                 $copyright = $config->get( 'RightsUrl' );
3407                         }
3408                 }
3409
3410                 if ( $copyright ) {
3411                         $tags['copyright'] = Html::element( 'link', [
3412                                 'rel' => 'license',
3413                                 'href' => $copyright ]
3414                         );
3415                 }
3416
3417                 # Feeds
3418                 if ( $config->get( 'Feed' ) ) {
3419                         $feedLinks = [];
3420
3421                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3422                                 # Use the page name for the title.  In principle, this could
3423                                 # lead to issues with having the same name for different feeds
3424                                 # corresponding to the same page, but we can't avoid that at
3425                                 # this low a level.
3426
3427                                 $feedLinks[] = $this->feedLink(
3428                                         $format,
3429                                         $link,
3430                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3431                                         $this->msg(
3432                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3433                                         )->text()
3434                                 );
3435                         }
3436
3437                         # Recent changes feed should appear on every page (except recentchanges,
3438                         # that would be redundant). Put it after the per-page feed to avoid
3439                         # changing existing behavior. It's still available, probably via a
3440                         # menu in your browser. Some sites might have a different feed they'd
3441                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3442                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3443                         # If so, use it instead.
3444                         $sitename = $config->get( 'Sitename' );
3445                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3446                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3447                                         // Note, this->feedLink escapes the url.
3448                                         $feedLinks[] = $this->feedLink(
3449                                                 $type,
3450                                                 $feedUrl,
3451                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3452                                         );
3453                                 }
3454                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3455                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3456                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3457                                         $feedLinks[] = $this->feedLink(
3458                                                 $format,
3459                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3460                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3461                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3462                                         );
3463                                 }
3464                         }
3465
3466                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3467                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3468                         # use OutputPage::addFeedLink() instead.
3469                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3470
3471                         $tags += $feedLinks;
3472                 }
3473
3474                 # Canonical URL
3475                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3476                         if ( $canonicalUrl !== false ) {
3477                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3478                         } else {
3479                                 if ( $this->isArticleRelated() ) {
3480                                         // This affects all requests where "setArticleRelated" is true. This is
3481                                         // typically all requests that show content (query title, curid, oldid, diff),
3482                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3483                                         // It does not apply to File pages and Special pages.
3484                                         // 'history' and 'info' actions address page metadata rather than the page
3485                                         // content itself, so they may not be canonicalized to the view page url.
3486                                         // TODO: this ought to be better encapsulated in the Action class.
3487                                         $action = Action::getActionName( $this->getContext() );
3488                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3489                                                 $query = "action={$action}";
3490                                         } else {
3491                                                 $query = '';
3492                                         }
3493                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3494                                 } else {
3495                                         $reqUrl = $this->getRequest()->getRequestURL();
3496                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3497                                 }
3498                         }
3499                 }
3500                 if ( $canonicalUrl !== false ) {
3501                         $tags[] = Html::element( 'link', [
3502                                 'rel' => 'canonical',
3503                                 'href' => $canonicalUrl
3504                         ] );
3505                 }
3506
3507                 return $tags;
3508         }
3509
3510         /**
3511          * Generate a "<link rel/>" for a feed.
3512          *
3513          * @param string $type Feed type
3514          * @param string $url URL to the feed
3515          * @param string $text Value of the "title" attribute
3516          * @return string HTML fragment
3517          */
3518         private function feedLink( $type, $url, $text ) {
3519                 return Html::element( 'link', [
3520                         'rel' => 'alternate',
3521                         'type' => "application/$type+xml",
3522                         'title' => $text,
3523                         'href' => $url ]
3524                 );
3525         }
3526
3527         /**
3528          * Add a local or specified stylesheet, with the given media options.
3529          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3530          *
3531          * @param string $style URL to the file
3532          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3533          * @param string $condition For IE conditional comments, specifying an IE version
3534          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3535          */
3536         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3537                 $options = [];
3538                 if ( $media ) {
3539                         $options['media'] = $media;
3540                 }
3541                 if ( $condition ) {
3542                         $options['condition'] = $condition;
3543                 }
3544                 if ( $dir ) {
3545                         $options['dir'] = $dir;
3546                 }
3547                 $this->styles[$style] = $options;
3548         }
3549
3550         /**
3551          * Adds inline CSS styles
3552          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3553          *
3554          * @param mixed $style_css Inline CSS
3555          * @param string $flip Set to 'flip' to flip the CSS if needed
3556          */
3557         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3558                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3559                         # If wanted, and the interface is right-to-left, flip the CSS
3560                         $style_css = CSSJanus::transform( $style_css, true, false );
3561                 }
3562                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3563         }
3564
3565         /**
3566          * Build exempt modules and legacy non-ResourceLoader styles.
3567          *
3568          * @return string|WrappedStringList HTML
3569          */
3570         protected function buildExemptModules() {
3571                 $chunks = [];
3572                 // Things that go after the ResourceLoaderDynamicStyles marker
3573                 $append = [];
3574
3575                 // We want site, private and user styles to override dynamically added styles from
3576                 // general modules, but we want dynamically added styles to override statically added
3577                 // style modules. So the order has to be:
3578                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3579                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3580                 // - ResourceLoaderDynamicStyles marker
3581                 // - site/private/user styles
3582
3583                 // Add legacy styles added through addStyle()/addInlineStyle() here
3584                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3585
3586                 $chunks[] = Html::element(
3587                         'meta',
3588                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3589                 );
3590
3591                 $separateReq = [ 'site.styles', 'user.styles' ];
3592                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3593                         // Combinable modules
3594                         $chunks[] = $this->makeResourceLoaderLink(
3595                                 array_diff( $moduleNames, $separateReq ),
3596                                 ResourceLoaderModule::TYPE_STYLES
3597                         );
3598
3599                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3600                                 // These require their own dedicated request in order to support "@import"
3601                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3602                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3603                                         ResourceLoaderModule::TYPE_STYLES
3604                                 );
3605                         }
3606                 }
3607
3608                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3609         }
3610
3611         /**
3612          * @return array
3613          */
3614         public function buildCssLinksArray() {
3615                 $links = [];
3616
3617                 foreach ( $this->styles as $file => $options ) {
3618                         $link = $this->styleLink( $file, $options );
3619                         if ( $link ) {
3620                                 $links[$file] = $link;
3621                         }
3622                 }
3623                 return $links;
3624         }
3625
3626         /**
3627          * Generate \<link\> tags for stylesheets
3628          *
3629          * @param string $style URL to the file
3630          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3631          * @return string HTML fragment
3632          */
3633         protected function styleLink( $style, array $options ) {
3634                 if ( isset( $options['dir'] ) ) {
3635                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3636                                 return '';
3637                         }
3638                 }
3639
3640                 if ( isset( $options['media'] ) ) {
3641                         $media = self::transformCssMedia( $options['media'] );
3642                         if ( is_null( $media ) ) {
3643                                 return '';
3644                         }
3645                 } else {
3646                         $media = 'all';
3647                 }
3648
3649                 if ( substr( $style, 0, 1 ) == '/' ||
3650                         substr( $style, 0, 5 ) == 'http:' ||
3651                         substr( $style, 0, 6 ) == 'https:' ) {
3652                         $url = $style;
3653                 } else {
3654                         $config = $this->getConfig();
3655                         // Append file hash as query parameter
3656                         $url = self::transformResourcePath(
3657                                 $config,
3658                                 $config->get( 'StylePath' ) . '/' . $style
3659                         );
3660                 }
3661
3662                 $link = Html::linkedStyle( $url, $media );
3663
3664                 if ( isset( $options['condition'] ) ) {
3665                         $condition = htmlspecialchars( $options['condition'] );
3666                         $link = "<!--[if $condition]>$link<![endif]-->";
3667                 }
3668                 return $link;
3669         }
3670
3671         /**
3672          * Transform path to web-accessible static resource.
3673          *
3674          * This is used to add a validation hash as query string.
3675          * This aids various behaviors:
3676          *
3677          * - Put long Cache-Control max-age headers on responses for improved
3678          *   cache performance.
3679          * - Get the correct version of a file as expected by the current page.
3680          * - Instantly get the updated version of a file after deployment.
3681          *
3682          * Avoid using this for urls included in HTML as otherwise clients may get different
3683          * versions of a resource when navigating the site depending on when the page was cached.
3684          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3685          * an external stylesheet).
3686          *
3687          * @since 1.27
3688          * @param Config $config
3689          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3690          * @return string URL
3691          */
3692         public static function transformResourcePath( Config $config, $path ) {
3693                 global $IP;
3694
3695                 $localDir = $IP;
3696                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3697                 if ( $remotePathPrefix === '' ) {
3698                         // The configured base path is required to be empty string for
3699                         // wikis in the domain root
3700                         $remotePath = '/';
3701                 } else {
3702                         $remotePath = $remotePathPrefix;
3703                 }
3704                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3705                         // - Path is outside wgResourceBasePath, ignore.
3706                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3707                         return $path;
3708                 }
3709                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3710                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3711                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3712                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3713                 $uploadPath = $config->get( 'UploadPath' );
3714                 if ( strpos( $path, $uploadPath ) === 0 ) {
3715                         $localDir = $config->get( 'UploadDirectory' );
3716                         $remotePathPrefix = $remotePath = $uploadPath;
3717                 }
3718
3719                 $path = RelPath::getRelativePath( $path, $remotePath );
3720                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3721         }
3722
3723         /**
3724          * Utility method for transformResourceFilePath().
3725          *
3726          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3727          *
3728          * @since 1.27
3729          * @param string $remotePathPrefix URL path prefix that points to $localPath
3730          * @param string $localPath File directory exposed at $remotePath
3731          * @param string $file Path to target file relative to $localPath
3732          * @return string URL
3733          */
3734         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3735                 $hash = md5_file( "$localPath/$file" );
3736                 if ( $hash === false ) {
3737                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3738                         $hash = '';
3739                 }
3740                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3741         }
3742
3743         /**
3744          * Transform "media" attribute based on request parameters
3745          *
3746          * @param string $media Current value of the "media" attribute
3747          * @return string Modified value of the "media" attribute, or null to skip
3748          * this stylesheet
3749          */
3750         public static function transformCssMedia( $media ) {
3751                 global $wgRequest;
3752
3753                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3754                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3755
3756                 // Switch in on-screen display for media testing
3757                 $switches = [
3758                         'printable' => 'print',
3759                         'handheld' => 'handheld',
3760                 ];
3761                 foreach ( $switches as $switch => $targetMedia ) {
3762                         if ( $wgRequest->getBool( $switch ) ) {
3763                                 if ( $media == $targetMedia ) {
3764                                         $media = '';
3765                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3766                                         /* This regex will not attempt to understand a comma-separated media_query_list
3767                                          *
3768                                          * Example supported values for $media:
3769                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3770                                          * Example NOT supported value for $media:
3771                                          * '3d-glasses, screen, print and resolution > 90dpi'
3772                                          *
3773                                          * If it's a print request, we never want any kind of screen stylesheets
3774                                          * If it's a handheld request (currently the only other choice with a switch),
3775                                          * we don't want simple 'screen' but we might want screen queries that
3776                                          * have a max-width or something, so we'll pass all others on and let the
3777                                          * client do the query.
3778                                          */
3779                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3780                                                 return null;
3781                                         }
3782                                 }
3783                         }
3784                 }
3785
3786                 return $media;
3787         }
3788
3789         /**
3790          * Add a wikitext-formatted message to the output.
3791          * This is equivalent to:
3792          *
3793          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3794          */
3795         public function addWikiMsg( /*...*/ ) {
3796                 $args = func_get_args();
3797                 $name = array_shift( $args );
3798                 $this->addWikiMsgArray( $name, $args );
3799         }
3800
3801         /**
3802          * Add a wikitext-formatted message to the output.
3803          * Like addWikiMsg() except the parameters are taken as an array
3804          * instead of a variable argument list.
3805          *
3806          * @param string $name
3807          * @param array $args
3808          */
3809         public function addWikiMsgArray( $name, $args ) {
3810                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3811         }
3812
3813         /**
3814          * This function takes a number of message/argument specifications, wraps them in
3815          * some overall structure, and then parses the result and adds it to the output.
3816          *
3817          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3818          * and so on. The subsequent arguments may be either
3819          * 1) strings, in which case they are message names, or
3820          * 2) arrays, in which case, within each array, the first element is the message
3821          *    name, and subsequent elements are the parameters to that message.
3822          *
3823          * Don't use this for messages that are not in the user's interface language.
3824          *
3825          * For example:
3826          *
3827          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3828          *
3829          * Is equivalent to:
3830          *
3831          *    $wgOut->addWikiText( "<div class='error'>\n"
3832          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3833          *
3834          * The newline after the opening div is needed in some wikitext. See T21226.
3835          *
3836          * @param string $wrap
3837          */
3838         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3839                 $msgSpecs = func_get_args();
3840                 array_shift( $msgSpecs );
3841                 $msgSpecs = array_values( $msgSpecs );
3842                 $s = $wrap;
3843                 foreach ( $msgSpecs as $n => $spec ) {
3844                         if ( is_array( $spec ) ) {
3845                                 $args = $spec;
3846                                 $name = array_shift( $args );
3847                                 if ( isset( $args['options'] ) ) {
3848                                         unset( $args['options'] );
3849                                         wfDeprecated(
3850                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3851                                                 '1.20'
3852                                         );
3853                                 }
3854                         } else {
3855                                 $args = [];
3856                                 $name = $spec;
3857                         }
3858                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3859                 }
3860                 $this->addWikiText( $s );
3861         }
3862
3863         /**
3864          * Whether the output has a table of contents
3865          * @return bool
3866          * @since 1.22
3867          */
3868         public function isTOCEnabled() {
3869                 return $this->mEnableTOC;
3870         }
3871
3872         /**
3873          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3874          * @param bool $flag
3875          * @since 1.23
3876          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3877          */
3878         public function enableSectionEditLinks( $flag = true ) {
3879                 wfDeprecated( __METHOD__, '1.31' );
3880         }
3881
3882         /**
3883          * @return bool
3884          * @since 1.23
3885          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3886          */
3887         public function sectionEditLinksEnabled() {
3888                 wfDeprecated( __METHOD__, '1.31' );
3889                 return true;
3890         }
3891
3892         /**
3893          * Helper function to setup the PHP implementation of OOUI to use in this request.
3894          *
3895          * @since 1.26
3896          * @param String $skinName The Skin name to determine the correct OOUI theme
3897          * @param String $dir Language direction
3898          */
3899         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
3900                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
3901                 $theme = $themes[$skinName] ?? $themes['default'];
3902                 // For example, 'OOUI\WikimediaUITheme'.
3903                 $themeClass = "OOUI\\{$theme}Theme";
3904                 OOUI\Theme::setSingleton( new $themeClass() );
3905                 OOUI\Element::setDefaultDir( $dir );
3906         }
3907
3908         /**
3909          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3910          * MediaWiki and this OutputPage instance.
3911          *
3912          * @since 1.25
3913          */
3914         public function enableOOUI() {
3915                 self::setupOOUI(
3916                         strtolower( $this->getSkin()->getSkinName() ),
3917                         $this->getLanguage()->getDir()
3918                 );
3919                 $this->addModuleStyles( [
3920                         'oojs-ui-core.styles',
3921                         'oojs-ui.styles.indicators',
3922                         'oojs-ui.styles.textures',
3923                         'mediawiki.widgets.styles',
3924                         'oojs-ui.styles.icons-content',
3925                         'oojs-ui.styles.icons-alerts',
3926                         'oojs-ui.styles.icons-interactions',
3927                 ] );
3928         }
3929
3930         /**
3931          * Add Link headers for preloading the wiki's logo.
3932          *
3933          * @since 1.26
3934          */
3935         protected function addLogoPreloadLinkHeaders() {
3936                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
3937
3938                 $tags = [];
3939                 $logosPerDppx = [];
3940                 $logos = [];
3941
3942                 if ( !is_array( $logo ) ) {
3943                         // No media queries required if we only have one variant
3944                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
3945                         return;
3946                 }
3947
3948                 if ( isset( $logo['svg'] ) ) {
3949                         // No media queries required if we only have a 1x and svg variant
3950                         // because all preload-capable browsers support SVGs
3951                         $this->addLinkHeader( '<' . $logo['svg'] . '>;rel=preload;as=image' );
3952                         return;
3953                 }
3954
3955                 foreach ( $logo as $dppx => $src ) {
3956                         // Keys are in this format: "1.5x"
3957                         $dppx = substr( $dppx, 0, -1 );
3958                         $logosPerDppx[$dppx] = $src;
3959                 }
3960
3961                 // Because PHP can't have floats as array keys
3962                 uksort( $logosPerDppx, function ( $a , $b ) {
3963                         $a = floatval( $a );
3964                         $b = floatval( $b );
3965                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
3966                         return $a <=> $b;
3967                 } );
3968
3969                 foreach ( $logosPerDppx as $dppx => $src ) {
3970                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
3971                 }
3972
3973                 $logosCount = count( $logos );
3974                 // Logic must match ResourceLoaderSkinModule:
3975                 // - 1x applies to resolution < 1.5dppx
3976                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
3977                 // - 2x applies to resolution >= 2dppx
3978                 // Note that min-resolution and max-resolution are both inclusive.
3979                 for ( $i = 0; $i < $logosCount; $i++ ) {
3980                         if ( $i === 0 ) {
3981                                 // Smallest dppx
3982                                 // min-resolution is ">=" (larger than or equal to)
3983                                 // "not min-resolution" is essentially "<"
3984                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
3985                         } elseif ( $i !== $logosCount - 1 ) {
3986                                 // In between
3987                                 // Media query expressions can only apply "not" to the entire expression
3988                                 // (e.g. can't express ">= 1.5 and not >= 2).
3989                                 // Workaround: Use <= 1.9999 in place of < 2.
3990                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
3991                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
3992                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
3993                         } else {
3994                                 // Largest dppx
3995                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
3996                         }
3997
3998                         $this->addLinkHeader(
3999                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
4000                         );
4001                 }
4002         }
4003
4004         /**
4005          * Get (and set if not yet set) the CSP nonce.
4006          *
4007          * This value needs to be included in any <script> tags on the
4008          * page.
4009          *
4010          * @return string|bool Nonce or false to mean don't output nonce
4011          * @since 1.32
4012          */
4013         public function getCSPNonce() {
4014                 if ( !ContentSecurityPolicy::isNonceRequired( $this->getConfig() ) ) {
4015                         return false;
4016                 }
4017                 if ( $this->CSPNonce === null ) {
4018                         // XXX It might be expensive to generate randomness
4019                         // on every request, on Windows.
4020                         $rand = random_bytes( 15 );
4021                         $this->CSPNonce = base64_encode( $rand );
4022                 }
4023                 return $this->CSPNonce;
4024         }
4025 }