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\MediaWikiServices;
  25 use MediaWiki\Session\SessionManager;
  26 use Wikimedia\Rdbms\IResultWrapper;
  27 use Wikimedia\RelPath;
  28 use Wikimedia\WrappedString;
  29 use Wikimedia\WrappedStringList;
  30
  31 /**
  32  * This class should be covered by a general architecture document which does
  33  * not exist as of January 2011.  This is one of the Core classes and should
  34  * be read at least once by any new developers.
  35  *
  36  * This class is used to prepare the final rendering. A skin is then
  37  * applied to the output parameters (links, javascript, html, categories ...).
  38  *
  39  * @todo FIXME: Another class handles sending the whole page to the client.
  40  *
  41  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  42  * in November 2010.
  43  *
  44  * @todo document
  45  */
  46 class OutputPage extends ContextSource {
  47         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  48         protected $mMetatags = [];
  49
  50         /** @var array */
  51         protected $mLinktags = [];
  52
  53         /** @var bool */
  54         protected $mCanonicalUrl = false;
  55
  56         /**
  57          * @var string The contents of <h1> */
  58         private $mPageTitle = '';
  59
  60         /**
  61          * @var string The displayed title of the page. Different from page title
  62          * if overridden by display title magic word or hooks. Can contain safe
  63          * HTML. Different from page title which may contain messages such as
  64          * "Editing X" which is displayed in h1. This can be used for other places
  65          * where the page name is referred on the page.
  66          */
  67         private $displayTitle;
  68
  69         /**
  70          * @var string Contains all of the "<body>" content. Should be private we
  71          *   got set/get accessors and the append() method.
  72          */
  73         public $mBodytext = '';
  74
  75         /** @var string Stores contents of "<title>" tag */
  76         private $mHTMLtitle = '';
  77
  78         /**
  79          * @var bool Is the displayed content related to the source of the
  80          *   corresponding wiki article.
  81          */
  82         private $mIsArticle = false;
  83
  84         /** @var bool Stores "article flag" toggle. */
  85         private $mIsArticleRelated = true;
  86
  87         /** @var bool Is the content subject to copyright */
  88         private $mHasCopyright = false;
  89
  90         /**
  91          * @var bool We have to set isPrintable(). Some pages should
  92          * never be printed (ex: redirections).
  93          */
  94         private $mPrintable = false;
  95
  96         /**
  97          * @var array Contains the page subtitle. Special pages usually have some
  98          *   links here. Don't confuse with site subtitle added by skins.
  99          */
 100         private $mSubtitle = [];
 101
 102         /** @var string */
 103         public $mRedirect = '';
 104
 105         /** @var int */
 106         protected $mStatusCode;
 107
 108         /**
 109          * @var string Used for sending cache control.
 110          *   The whole caching system should probably be moved into its own class.
 111          */
 112         protected $mLastModified = '';
 113
 114         /** @var array */
 115         protected $mCategoryLinks = [];
 116
 117         /** @var array */
 118         protected $mCategories = [
 119                 'hidden' => [],
 120                 'normal' => [],
 121         ];
 122
 123         /** @var array */
 124         protected $mIndicators = [];
 125
 126         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 127         private $mLanguageLinks = [];
 128
 129         /**
 130          * Used for JavaScript (predates ResourceLoader)
 131          * @todo We should split JS / CSS.
 132          * mScripts content is inserted as is in "<head>" by Skin. This might
 133          * contain either a link to a stylesheet or inline CSS.
 134          */
 135         private $mScripts = '';
 136
 137         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 138         protected $mInlineStyles = '';
 139
 140         /**
 141          * @var string Used by skin template.
 142          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 143          */
 144         public $mPageLinkTitle = '';
 145
 146         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 147         protected $mHeadItems = [];
 148
 149         /** @var array Additional <body> classes; there are also <body> classes from other sources */
 150         protected $mAdditionalBodyClasses = [];
 151
 152         /** @var array */
 153         protected $mModules = [];
 154
 155         /** @var array */
 156         protected $mModuleScripts = [];
 157
 158         /** @var array */
 159         protected $mModuleStyles = [];
 160
 161         /** @var ResourceLoader */
 162         protected $mResourceLoader;
 163
 164         /** @var ResourceLoaderClientHtml */
 165         private $rlClient;
 166
 167         /** @var ResourceLoaderContext */
 168         private $rlClientContext;
 169
 170         /** @var array */
 171         private $rlExemptStyleModules;
 172
 173         /** @var array */
 174         protected $mJsConfigVars = [];
 175
 176         /** @var array */
 177         protected $mTemplateIds = [];
 178
 179         /** @var array */
 180         protected $mImageTimeKeys = [];
 181
 182         /** @var string */
 183         public $mRedirectCode = '';
 184
 185         protected $mFeedLinksAppendQuery = null;
 186
 187         /** @var array
 188          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 189          * @see ResourceLoaderModule::$origin
 190          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 191          */
 192         protected $mAllowedModules = [
 193                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 194         ];
 195
 196         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 197         protected $mDoNothing = false;
 198
 199         // Parser related.
 200
 201         /** @var int */
 202         protected $mContainsNewMagic = 0;
 203
 204         /**
 205          * lazy initialised, use parserOptions()
 206          * @var ParserOptions
 207          */
 208         protected $mParserOptions = null;
 209
 210         /**
 211          * Handles the Atom / RSS links.
 212          * We probably only support Atom in 2011.
 213          * @see $wgAdvertisedFeedTypes
 214          */
 215         private $mFeedLinks = [];
 216
 217         // Gwicke work on squid caching? Roughly from 2003.
 218         protected $mEnableClientCache = true;
 219
 220         /** @var bool Flag if output should only contain the body of the article. */
 221         private $mArticleBodyOnly = false;
 222
 223         /** @var bool */
 224         protected $mNewSectionLink = false;
 225
 226         /** @var bool */
 227         protected $mHideNewSectionLink = false;
 228
 229         /**
 230          * @var bool Comes from the parser. This was probably made to load CSS/JS
 231          * only if we had "<gallery>". Used directly in CategoryPage.php.
 232          * Looks like ResourceLoader can replace this.
 233          */
 234         public $mNoGallery = false;
 235
 236         /** @var int Cache stuff. Looks like mEnableClientCache */
 237         protected $mCdnMaxage = 0;
 238         /** @var int Upper limit on mCdnMaxage */
 239         protected $mCdnMaxageLimit = INF;
 240
 241         /**
 242          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 243          * be sent. This should be done for pages where edit actions are possible.
 244          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 245          */
 246         protected $mPreventClickjacking = true;
 247
 248         /** @var int To include the variable {{REVISIONID}} */
 249         private $mRevisionId = null;
 250
 251         /** @var string */
 252         private $mRevisionTimestamp = null;
 253
 254         /** @var array */
 255         protected $mFileVersion = null;
 256
 257         /**
 258          * @var array An array of stylesheet filenames (relative from skins path),
 259          * with options for CSS media, IE conditions, and RTL/LTR direction.
 260          * For internal use; add settings in the skin via $this->addStyle()
 261          *
 262          * Style again! This seems like a code duplication since we already have
 263          * mStyles. This is what makes Open Source amazing.
 264          */
 265         protected $styles = [];
 266
 267         private $mIndexPolicy = 'index';
 268         private $mFollowPolicy = 'follow';
 269
 270         /**
 271          * @var array Headers that cause the cache to vary.  Key is header name, value is an array of
 272          * options for the Key header.
 273          */
 274         private $mVaryHeader = [
 275                 'Accept-Encoding' => [ 'match=gzip' ],
 276         ];
 277
 278         /**
 279          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 280          * of the redirect.
 281          *
 282          * @var Title
 283          */
 284         private $mRedirectedFrom = null;
 285
 286         /**
 287          * Additional key => value data
 288          */
 289         private $mProperties = [];
 290
 291         /**
 292          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 293          */
 294         private $mTarget = null;
 295
 296         /**
 297          * @var bool Whether parser output contains a table of contents
 298          */
 299         private $mEnableTOC = false;
 300
 301         /**
 302          * @var string|null The URL to send in a <link> element with rel=license
 303          */
 304         private $copyrightUrl;
 305
 306         /** @var array Profiling data */
 307         private $limitReportJSData = [];
 308
 309         /** @var array Map Title to Content */
 310         private $contentOverrides = [];
 311
 312         /** @var callable[] */
 313         private $contentOverrideCallbacks = [];
 314
 315         /**
 316          * Link: header contents
 317          */
 318         private $mLinkHeader = [];
 319
 320         /**
 321          * @var string The nonce for Content-Security-Policy
 322          */
 323         private $CSPNonce;
 324
 325         /**
 326          * @var array A cache of the names of the cookies that will influence the cache
 327          */
 328         private static $cacheVaryCookies = null;
 329
 330         /**
 331          * Constructor for OutputPage. This should not be called directly.
 332          * Instead a new RequestContext should be created and it will implicitly create
 333          * a OutputPage tied to that context.
 334          * @param IContextSource $context
 335          */
 336         function __construct( IContextSource $context ) {
 337                 $this->setContext( $context );
 338         }
 339
 340         /**
 341          * Redirect to $url rather than displaying the normal page
 342          *
 343          * @param string $url
 344          * @param string $responsecode HTTP status code
 345          */
 346         public function redirect( $url, $responsecode = '302' ) {
 347                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 348                 $this->mRedirect = str_replace( "\n", '', $url );
 349                 $this->mRedirectCode = $responsecode;
 350         }
 351
 352         /**
 353          * Get the URL to redirect to, or an empty string if not redirect URL set
 354          *
 355          * @return string
 356          */
 357         public function getRedirect() {
 358                 return $this->mRedirect;
 359         }
 360
 361         /**
 362          * Set the copyright URL to send with the output.
 363          * Empty string to omit, null to reset.
 364          *
 365          * @since 1.26
 366          *
 367          * @param string|null $url
 368          */
 369         public function setCopyrightUrl( $url ) {
 370                 $this->copyrightUrl = $url;
 371         }
 372
 373         /**
 374          * Set the HTTP status code to send with the output.
 375          *
 376          * @param int $statusCode
 377          */
 378         public function setStatusCode( $statusCode ) {
 379                 $this->mStatusCode = $statusCode;
 380         }
 381
 382         /**
 383          * Add a new "<meta>" tag
 384          * To add an http-equiv meta tag, precede the name with "http:"
 385          *
 386          * @param string $name Name of the meta tag
 387          * @param string $val Value of the meta tag
 388          */
 389         function addMeta( $name, $val ) {
 390                 array_push( $this->mMetatags, [ $name, $val ] );
 391         }
 392
 393         /**
 394          * Returns the current <meta> tags
 395          *
 396          * @since 1.25
 397          * @return array
 398          */
 399         public function getMetaTags() {
 400                 return $this->mMetatags;
 401         }
 402
 403         /**
 404          * Add a new \<link\> tag to the page header.
 405          *
 406          * Note: use setCanonicalUrl() for rel=canonical.
 407          *
 408          * @param array $linkarr Associative array of attributes.
 409          */
 410         function addLink( array $linkarr ) {
 411                 array_push( $this->mLinktags, $linkarr );
 412         }
 413
 414         /**
 415          * Returns the current <link> tags
 416          *
 417          * @since 1.25
 418          * @return array
 419          */
 420         public function getLinkTags() {
 421                 return $this->mLinktags;
 422         }
 423
 424         /**
 425          * Set the URL to be used for the <link rel=canonical>. This should be used
 426          * in preference to addLink(), to avoid duplicate link tags.
 427          * @param string $url
 428          */
 429         function setCanonicalUrl( $url ) {
 430                 $this->mCanonicalUrl = $url;
 431         }
 432
 433         /**
 434          * Returns the URL to be used for the <link rel=canonical> if
 435          * one is set.
 436          *
 437          * @since 1.25
 438          * @return bool|string
 439          */
 440         public function getCanonicalUrl() {
 441                 return $this->mCanonicalUrl;
 442         }
 443
 444         /**
 445          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 446          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 447          * if possible.
 448          *
 449          * @param string $script Raw HTML
 450          */
 451         function addScript( $script ) {
 452                 $this->mScripts .= $script;
 453         }
 454
 455         /**
 456          * Add a JavaScript file to be loaded as `<script>` on this page.
 457          *
 458          * Internal use only. Use OutputPage::addModules() if possible.
 459          *
 460          * @param string $file URL to file (absolute path, protocol-relative, or full url)
 461          * @param string|null $unused Previously used to change the cache-busting query parameter
 462          */
 463         public function addScriptFile( $file, $unused = null ) {
 464                 if ( substr( $file, 0, 1 ) !== '/' && !preg_match( '#^[a-z]*://#i', $file ) ) {
 465                         // This is not an absolute path, protocol-relative url, or full scheme url,
 466                         // presumed to be an old call intended to include a file from /w/skins/common,
 467                         // which doesn't exist anymore as of MediaWiki 1.24 per T71277. Ignore.
 468                         wfDeprecated( __METHOD__, '1.24' );
 469                         return;
 470                 }
 471                 $this->addScript( Html::linkedScript( $file, $this->getCSPNonce() ) );
 472         }
 473
 474         /**
 475          * Add a self-contained script tag with the given contents
 476          * Internal use only. Use OutputPage::addModules() if possible.
 477          *
 478          * @param string $script JavaScript text, no script tags
 479          */
 480         public function addInlineScript( $script ) {
 481                 $this->mScripts .= Html::inlineScript( "\n$script\n", $this->getCSPNonce() ) . "\n";
 482         }
 483
 484         /**
 485          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 486          * which are no longer registered (eg a page is cached before an extension is disabled)
 487          * @param array $modules
 488          * @param string|null $position Unused
 489          * @param string $type
 490          * @return array
 491          */
 492         protected function filterModules( array $modules, $position = null,
 493                 $type = ResourceLoaderModule::TYPE_COMBINED
 494         ) {
 495                 $resourceLoader = $this->getResourceLoader();
 496                 $filteredModules = [];
 497                 foreach ( $modules as $val ) {
 498                         $module = $resourceLoader->getModule( $val );
 499                         if ( $module instanceof ResourceLoaderModule
 500                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 501                         ) {
 502                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 503                                         $this->warnModuleTargetFilter( $module->getName() );
 504                                         continue;
 505                                 }
 506                                 $filteredModules[] = $val;
 507                         }
 508                 }
 509                 return $filteredModules;
 510         }
 511
 512         private function warnModuleTargetFilter( $moduleName ) {
 513                 static $warnings = [];
 514                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 515                         return;
 516                 }
 517                 $warnings[$this->mTarget][$moduleName] = true;
 518                 $this->getResourceLoader()->getLogger()->debug(
 519                         'Module "{module}" not loadable on target "{target}".',
 520                         [
 521                                 'module' => $moduleName,
 522                                 'target' => $this->mTarget,
 523                         ]
 524                 );
 525         }
 526
 527         /**
 528          * Get the list of modules to include on this page
 529          *
 530          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 531          * @param string|null $position Unused
 532          * @param string $param
 533          * @param string $type
 534          * @return array Array of module names
 535          */
 536         public function getModules( $filter = false, $position = null, $param = 'mModules',
 537                 $type = ResourceLoaderModule::TYPE_COMBINED
 538         ) {
 539                 $modules = array_values( array_unique( $this->$param ) );
 540                 return $filter
 541                         ? $this->filterModules( $modules, null, $type )
 542                         : $modules;
 543         }
 544
 545         /**
 546          * Load one or more ResourceLoader modules on this page.
 547          *
 548          * @param string|array $modules Module name (string) or array of module names
 549          */
 550         public function addModules( $modules ) {
 551                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 552         }
 553
 554         /**
 555          * Get the list of script-only modules to load on this page.
 556          *
 557          * @param bool $filter
 558          * @param string|null $position Unused
 559          * @return array Array of module names
 560          */
 561         public function getModuleScripts( $filter = false, $position = null ) {
 562                 return $this->getModules( $filter, null, 'mModuleScripts',
 563                         ResourceLoaderModule::TYPE_SCRIPTS
 564                 );
 565         }
 566
 567         /**
 568          * Load the scripts of one or more ResourceLoader modules, on this page.
 569          *
 570          * This method exists purely to provide the legacy behaviour of loading
 571          * a module's scripts in the global scope, and without dependency resolution.
 572          * See <https://phabricator.wikimedia.org/T188689>.
 573          *
 574          * @deprecated since 1.31 Use addModules() instead.
 575          * @param string|array $modules Module name (string) or array of module names
 576          */
 577         public function addModuleScripts( $modules ) {
 578                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 579         }
 580
 581         /**
 582          * Get the list of style-only modules to load on this page.
 583          *
 584          * @param bool $filter
 585          * @param string|null $position Unused
 586          * @return array Array of module names
 587          */
 588         public function getModuleStyles( $filter = false, $position = null ) {
 589                 return $this->getModules( $filter, null, 'mModuleStyles',
 590                         ResourceLoaderModule::TYPE_STYLES
 591                 );
 592         }
 593
 594         /**
 595          * Load the styles of one or more ResourceLoader modules on this page.
 596          *
 597          * Module styles added through this function will be loaded as a stylesheet,
 598          * using a standard `<link rel=stylesheet>` HTML tag, rather than as a combined
 599          * Javascript and CSS package. Thus, they will even load when JavaScript is disabled.
 600          *
 601          * @param string|array $modules Module name (string) or array of module names
 602          */
 603         public function addModuleStyles( $modules ) {
 604                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 605         }
 606
 607         /**
 608          * @return null|string ResourceLoader target
 609          */
 610         public function getTarget() {
 611                 return $this->mTarget;
 612         }
 613
 614         /**
 615          * Sets ResourceLoader target for load.php links. If null, will be omitted
 616          *
 617          * @param string|null $target
 618          */
 619         public function setTarget( $target ) {
 620                 $this->mTarget = $target;
 621         }
 622
 623         /**
 624          * Add a mapping from a LinkTarget to a Content, for things like page preview.
 625          * @see self::addContentOverrideCallback()
 626          * @since 1.32
 627          * @param LinkTarget $target
 628          * @param Content $content
 629          */
 630         public function addContentOverride( LinkTarget $target, Content $content ) {
 631                 if ( !$this->contentOverrides ) {
 632                         // Register a callback for $this->contentOverrides on the first call
 633                         $this->addContentOverrideCallback( function ( LinkTarget $target ) {
 634                                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 635                                 return $this->contentOverrides[$key] ?? null;
 636                         } );
 637                 }
 638
 639                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 640                 $this->contentOverrides[$key] = $content;
 641         }
 642
 643         /**
 644          * Add a callback for mapping from a Title to a Content object, for things
 645          * like page preview.
 646          * @see ResourceLoaderContext::getContentOverrideCallback()
 647          * @since 1.32
 648          * @param callable $callback
 649          */
 650         public function addContentOverrideCallback( callable $callback ) {
 651                 $this->contentOverrideCallbacks[] = $callback;
 652         }
 653
 654         /**
 655          * Get an array of head items
 656          *
 657          * @return array
 658          */
 659         function getHeadItemsArray() {
 660                 return $this->mHeadItems;
 661         }
 662
 663         /**
 664          * Add or replace a head item to the output
 665          *
 666          * Whenever possible, use more specific options like ResourceLoader modules,
 667          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 668          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 669          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 670          * This would be your very LAST fallback.
 671          *
 672          * @param string $name Item name
 673          * @param string $value Raw HTML
 674          */
 675         public function addHeadItem( $name, $value ) {
 676                 $this->mHeadItems[$name] = $value;
 677         }
 678
 679         /**
 680          * Add one or more head items to the output
 681          *
 682          * @since 1.28
 683          * @param string|string[] $values Raw HTML
 684          */
 685         public function addHeadItems( $values ) {
 686                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 687         }
 688
 689         /**
 690          * Check if the header item $name is already set
 691          *
 692          * @param string $name Item name
 693          * @return bool
 694          */
 695         public function hasHeadItem( $name ) {
 696                 return isset( $this->mHeadItems[$name] );
 697         }
 698
 699         /**
 700          * Add a class to the <body> element
 701          *
 702          * @since 1.30
 703          * @param string|string[] $classes One or more classes to add
 704          */
 705         public function addBodyClasses( $classes ) {
 706                 $this->mAdditionalBodyClasses = array_merge( $this->mAdditionalBodyClasses, (array)$classes );
 707         }
 708
 709         /**
 710          * Set whether the output should only contain the body of the article,
 711          * without any skin, sidebar, etc.
 712          * Used e.g. when calling with "action=render".
 713          *
 714          * @param bool $only Whether to output only the body of the article
 715          */
 716         public function setArticleBodyOnly( $only ) {
 717                 $this->mArticleBodyOnly = $only;
 718         }
 719
 720         /**
 721          * Return whether the output will contain only the body of the article
 722          *
 723          * @return bool
 724          */
 725         public function getArticleBodyOnly() {
 726                 return $this->mArticleBodyOnly;
 727         }
 728
 729         /**
 730          * Set an additional output property
 731          * @since 1.21
 732          *
 733          * @param string $name
 734          * @param mixed $value
 735          */
 736         public function setProperty( $name, $value ) {
 737                 $this->mProperties[$name] = $value;
 738         }
 739
 740         /**
 741          * Get an additional output property
 742          * @since 1.21
 743          *
 744          * @param string $name
 745          * @return mixed Property value or null if not found
 746          */
 747         public function getProperty( $name ) {
 748                 return $this->mProperties[$name] ?? null;
 749         }
 750
 751         /**
 752          * checkLastModified tells the client to use the client-cached page if
 753          * possible. If successful, the OutputPage is disabled so that
 754          * any future call to OutputPage->output() have no effect.
 755          *
 756          * Side effect: sets mLastModified for Last-Modified header
 757          *
 758          * @param string $timestamp
 759          *
 760          * @return bool True if cache-ok headers was sent.
 761          */
 762         public function checkLastModified( $timestamp ) {
 763                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 764                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 765                         return false;
 766                 }
 767                 $config = $this->getConfig();
 768                 if ( !$config->get( 'CachePages' ) ) {
 769                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 770                         return false;
 771                 }
 772
 773                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 774                 $modifiedTimes = [
 775                         'page' => $timestamp,
 776                         'user' => $this->getUser()->getTouched(),
 777                         'epoch' => $config->get( 'CacheEpoch' )
 778                 ];
 779                 if ( $config->get( 'UseSquid' ) ) {
 780                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, $this->getCdnCacheEpoch(
 781                                 time(),
 782                                 $config->get( 'SquidMaxage' )
 783                         ) );
 784                 }
 785                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 786
 787                 $maxModified = max( $modifiedTimes );
 788                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 789
 790                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 791                 if ( $clientHeader === false ) {
 792                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 793                         return false;
 794                 }
 795
 796                 # IE sends sizes after the date like this:
 797                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 798                 # this breaks strtotime().
 799                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 800
 801                 Wikimedia\suppressWarnings(); // E_STRICT system time warnings
 802                 $clientHeaderTime = strtotime( $clientHeader );
 803                 Wikimedia\restoreWarnings();
 804                 if ( !$clientHeaderTime ) {
 805                         wfDebug( __METHOD__
 806                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 807                         return false;
 808                 }
 809                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 810
 811                 # Make debug info
 812                 $info = '';
 813                 foreach ( $modifiedTimes as $name => $value ) {
 814                         if ( $info !== '' ) {
 815                                 $info .= ', ';
 816                         }
 817                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 818                 }
 819
 820                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 821                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 822                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 823                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 824                 if ( $clientHeaderTime < $maxModified ) {
 825                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 826                         return false;
 827                 }
 828
 829                 # Not modified
 830                 # Give a 304 Not Modified response code and disable body output
 831                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 832                 ini_set( 'zlib.output_compression', 0 );
 833                 $this->getRequest()->response()->statusHeader( 304 );
 834                 $this->sendCacheControl();
 835                 $this->disable();
 836
 837                 // Don't output a compressed blob when using ob_gzhandler;
 838                 // it's technically against HTTP spec and seems to confuse
 839                 // Firefox when the response gets split over two packets.
 840                 wfClearOutputBuffers();
 841
 842                 return true;
 843         }
 844
 845         /**
 846          * @param int $reqTime Time of request (eg. now)
 847          * @param int $maxAge Cache TTL in seconds
 848          * @return int Timestamp
 849          */
 850         private function getCdnCacheEpoch( $reqTime, $maxAge ) {
 851                 // Ensure Last-Modified is never more than (wgSquidMaxage) in the past,
 852                 // because even if the wiki page content hasn't changed since, static
 853                 // resources may have changed (skin HTML, interface messages, urls, etc.)
 854                 // and must roll-over in a timely manner (T46570)
 855                 return $reqTime - $maxAge;
 856         }
 857
 858         /**
 859          * Override the last modified timestamp
 860          *
 861          * @param string $timestamp New timestamp, in a format readable by
 862          *        wfTimestamp()
 863          */
 864         public function setLastModified( $timestamp ) {
 865                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 866         }
 867
 868         /**
 869          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 870          *
 871          * @param string $policy The literal string to output as the contents of
 872          *   the meta tag.  Will be parsed according to the spec and output in
 873          *   standardized form.
 874          * @return null
 875          */
 876         public function setRobotPolicy( $policy ) {
 877                 $policy = Article::formatRobotPolicy( $policy );
 878
 879                 if ( isset( $policy['index'] ) ) {
 880                         $this->setIndexPolicy( $policy['index'] );
 881                 }
 882                 if ( isset( $policy['follow'] ) ) {
 883                         $this->setFollowPolicy( $policy['follow'] );
 884                 }
 885         }
 886
 887         /**
 888          * Set the index policy for the page, but leave the follow policy un-
 889          * touched.
 890          *
 891          * @param string $policy Either 'index' or 'noindex'.
 892          * @return null
 893          */
 894         public function setIndexPolicy( $policy ) {
 895                 $policy = trim( $policy );
 896                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 897                         $this->mIndexPolicy = $policy;
 898                 }
 899         }
 900
 901         /**
 902          * Set the follow policy for the page, but leave the index policy un-
 903          * touched.
 904          *
 905          * @param string $policy Either 'follow' or 'nofollow'.
 906          * @return null
 907          */
 908         public function setFollowPolicy( $policy ) {
 909                 $policy = trim( $policy );
 910                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 911                         $this->mFollowPolicy = $policy;
 912                 }
 913         }
 914
 915         /**
 916          * "HTML title" means the contents of "<title>".
 917          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 918          *
 919          * @param string|Message $name
 920          */
 921         public function setHTMLTitle( $name ) {
 922                 if ( $name instanceof Message ) {
 923                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 924                 } else {
 925                         $this->mHTMLtitle = $name;
 926                 }
 927         }
 928
 929         /**
 930          * Return the "HTML title", i.e. the content of the "<title>" tag.
 931          *
 932          * @return string
 933          */
 934         public function getHTMLTitle() {
 935                 return $this->mHTMLtitle;
 936         }
 937
 938         /**
 939          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 940          *
 941          * @param Title $t
 942          */
 943         public function setRedirectedFrom( $t ) {
 944                 $this->mRedirectedFrom = $t;
 945         }
 946
 947         /**
 948          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 949          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 950          * but not bad tags like \<script\>. This function automatically sets
 951          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 952          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 953          * good tags like \<i\> will be dropped entirely.
 954          *
 955          * @param string|Message $name
 956          */
 957         public function setPageTitle( $name ) {
 958                 if ( $name instanceof Message ) {
 959                         $name = $name->setContext( $this->getContext() )->text();
 960                 }
 961
 962                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 963                 # but leave "<i>foobar</i>" alone
 964                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 965                 $this->mPageTitle = $nameWithTags;
 966
 967                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 968                 $this->setHTMLTitle(
 969                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 970                                 ->inContentLanguage()
 971                 );
 972         }
 973
 974         /**
 975          * Return the "page title", i.e. the content of the \<h1\> tag.
 976          *
 977          * @return string
 978          */
 979         public function getPageTitle() {
 980                 return $this->mPageTitle;
 981         }
 982
 983         /**
 984          * Same as page title but only contains name of the page, not any other text.
 985          *
 986          * @since 1.32
 987          * @param string $html Page title text.
 988          * @see OutputPage::setPageTitle
 989          */
 990         public function setDisplayTitle( $html ) {
 991                 $this->displayTitle = $html;
 992         }
 993
 994         /**
 995          * Returns page display title.
 996          *
 997          * Performs some normalization, but this not as strict the magic word.
 998          *
 999          * @since 1.32
1000          * @return string HTML
1001          */
1002         public function getDisplayTitle() {
1003                 $html = $this->displayTitle;
1004                 if ( $html === null ) {
1005                         $html = $this->getTitle()->getPrefixedText();
1006                 }
1007
1008                 return Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $html ) );
1009         }
1010
1011         /**
1012          * Returns page display title without namespace prefix if possible.
1013          *
1014          * @since 1.32
1015          * @return string HTML
1016          */
1017         public function getUnprefixedDisplayTitle() {
1018                 $text = $this->getDisplayTitle();
1019                 $nsPrefix = $this->getTitle()->getNsText() . ':';
1020                 $prefix = preg_quote( $nsPrefix, '/' );
1021
1022                 return preg_replace( "/^$prefix/i", '', $text );
1023         }
1024
1025         /**
1026          * Set the Title object to use
1027          *
1028          * @param Title $t
1029          */
1030         public function setTitle( Title $t ) {
1031                 $this->getContext()->setTitle( $t );
1032         }
1033
1034         /**
1035          * Replace the subtitle with $str
1036          *
1037          * @param string|Message $str New value of the subtitle. String should be safe HTML.
1038          */
1039         public function setSubtitle( $str ) {
1040                 $this->clearSubtitle();
1041                 $this->addSubtitle( $str );
1042         }
1043
1044         /**
1045          * Add $str to the subtitle
1046          *
1047          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
1048          */
1049         public function addSubtitle( $str ) {
1050                 if ( $str instanceof Message ) {
1051                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
1052                 } else {
1053                         $this->mSubtitle[] = $str;
1054                 }
1055         }
1056
1057         /**
1058          * Build message object for a subtitle containing a backlink to a page
1059          *
1060          * @param Title $title Title to link to
1061          * @param array $query Array of additional parameters to include in the link
1062          * @return Message
1063          * @since 1.25
1064          */
1065         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1066                 if ( $title->isRedirect() ) {
1067                         $query['redirect'] = 'no';
1068                 }
1069                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1070                 return wfMessage( 'backlinksubtitle' )
1071                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1072         }
1073
1074         /**
1075          * Add a subtitle containing a backlink to a page
1076          *
1077          * @param Title $title Title to link to
1078          * @param array $query Array of additional parameters to include in the link
1079          */
1080         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1081                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1082         }
1083
1084         /**
1085          * Clear the subtitles
1086          */
1087         public function clearSubtitle() {
1088                 $this->mSubtitle = [];
1089         }
1090
1091         /**
1092          * Get the subtitle
1093          *
1094          * @return string
1095          */
1096         public function getSubtitle() {
1097                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1098         }
1099
1100         /**
1101          * Set the page as printable, i.e. it'll be displayed with all
1102          * print styles included
1103          */
1104         public function setPrintable() {
1105                 $this->mPrintable = true;
1106         }
1107
1108         /**
1109          * Return whether the page is "printable"
1110          *
1111          * @return bool
1112          */
1113         public function isPrintable() {
1114                 return $this->mPrintable;
1115         }
1116
1117         /**
1118          * Disable output completely, i.e. calling output() will have no effect
1119          */
1120         public function disable() {
1121                 $this->mDoNothing = true;
1122         }
1123
1124         /**
1125          * Return whether the output will be completely disabled
1126          *
1127          * @return bool
1128          */
1129         public function isDisabled() {
1130                 return $this->mDoNothing;
1131         }
1132
1133         /**
1134          * Show an "add new section" link?
1135          *
1136          * @return bool
1137          */
1138         public function showNewSectionLink() {
1139                 return $this->mNewSectionLink;
1140         }
1141
1142         /**
1143          * Forcibly hide the new section link?
1144          *
1145          * @return bool
1146          */
1147         public function forceHideNewSectionLink() {
1148                 return $this->mHideNewSectionLink;
1149         }
1150
1151         /**
1152          * Add or remove feed links in the page header
1153          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1154          * for the new version
1155          * @see addFeedLink()
1156          *
1157          * @param bool $show True: add default feeds, false: remove all feeds
1158          */
1159         public function setSyndicated( $show = true ) {
1160                 if ( $show ) {
1161                         $this->setFeedAppendQuery( false );
1162                 } else {
1163                         $this->mFeedLinks = [];
1164                 }
1165         }
1166
1167         /**
1168          * Add default feeds to the page header
1169          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1170          * for the new version
1171          * @see addFeedLink()
1172          *
1173          * @param string $val Query to append to feed links or false to output
1174          *        default links
1175          */
1176         public function setFeedAppendQuery( $val ) {
1177                 $this->mFeedLinks = [];
1178
1179                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1180                         $query = "feed=$type";
1181                         if ( is_string( $val ) ) {
1182                                 $query .= '&' . $val;
1183                         }
1184                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1185                 }
1186         }
1187
1188         /**
1189          * Add a feed link to the page header
1190          *
1191          * @param string $format Feed type, should be a key of $wgFeedClasses
1192          * @param string $href URL
1193          */
1194         public function addFeedLink( $format, $href ) {
1195                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1196                         $this->mFeedLinks[$format] = $href;
1197                 }
1198         }
1199
1200         /**
1201          * Should we output feed links for this page?
1202          * @return bool
1203          */
1204         public function isSyndicated() {
1205                 return count( $this->mFeedLinks ) > 0;
1206         }
1207
1208         /**
1209          * Return URLs for each supported syndication format for this page.
1210          * @return array Associating format keys with URLs
1211          */
1212         public function getSyndicationLinks() {
1213                 return $this->mFeedLinks;
1214         }
1215
1216         /**
1217          * Will currently always return null
1218          *
1219          * @return null
1220          */
1221         public function getFeedAppendQuery() {
1222                 return $this->mFeedLinksAppendQuery;
1223         }
1224
1225         /**
1226          * Set whether the displayed content is related to the source of the
1227          * corresponding article on the wiki
1228          * Setting true will cause the change "article related" toggle to true
1229          *
1230          * @param bool $newVal
1231          */
1232         public function setArticleFlag( $newVal ) {
1233                 $this->mIsArticle = $newVal;
1234                 if ( $newVal ) {
1235                         $this->mIsArticleRelated = $newVal;
1236                 }
1237         }
1238
1239         /**
1240          * Return whether the content displayed page is related to the source of
1241          * the corresponding article on the wiki
1242          *
1243          * @return bool
1244          */
1245         public function isArticle() {
1246                 return $this->mIsArticle;
1247         }
1248
1249         /**
1250          * Set whether this page is related an article on the wiki
1251          * Setting false will cause the change of "article flag" toggle to false
1252          *
1253          * @param bool $newVal
1254          */
1255         public function setArticleRelated( $newVal ) {
1256                 $this->mIsArticleRelated = $newVal;
1257                 if ( !$newVal ) {
1258                         $this->mIsArticle = false;
1259                 }
1260         }
1261
1262         /**
1263          * Return whether this page is related an article on the wiki
1264          *
1265          * @return bool
1266          */
1267         public function isArticleRelated() {
1268                 return $this->mIsArticleRelated;
1269         }
1270
1271         /**
1272          * Set whether the standard copyright should be shown for the current page.
1273          *
1274          * @param bool $hasCopyright
1275          */
1276         public function setCopyright( $hasCopyright ) {
1277                 $this->mHasCopyright = $hasCopyright;
1278         }
1279
1280         /**
1281          * Return whether the standard copyright should be shown for the current page.
1282          * By default, it is true for all articles but other pages
1283          * can signal it by using setCopyright( true ).
1284          *
1285          * Used by SkinTemplate to decided whether to show the copyright.
1286          *
1287          * @return bool
1288          */
1289         public function showsCopyright() {
1290                 return $this->isArticle() || $this->mHasCopyright;
1291         }
1292
1293         /**
1294          * Add new language links
1295          *
1296          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1297          *                               (e.g. 'fr:Test page')
1298          */
1299         public function addLanguageLinks( array $newLinkArray ) {
1300                 $this->mLanguageLinks = array_merge( $this->mLanguageLinks, $newLinkArray );
1301         }
1302
1303         /**
1304          * Reset the language links and add new language links
1305          *
1306          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1307          *                               (e.g. 'fr:Test page')
1308          */
1309         public function setLanguageLinks( array $newLinkArray ) {
1310                 $this->mLanguageLinks = $newLinkArray;
1311         }
1312
1313         /**
1314          * Get the list of language links
1315          *
1316          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1317          */
1318         public function getLanguageLinks() {
1319                 return $this->mLanguageLinks;
1320         }
1321
1322         /**
1323          * Add an array of categories, with names in the keys
1324          *
1325          * @param array $categories Mapping category name => sort key
1326          */
1327         public function addCategoryLinks( array $categories ) {
1328                 if ( !$categories ) {
1329                         return;
1330                 }
1331
1332                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1333
1334                 # Set all the values to 'normal'.
1335                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1336
1337                 # Mark hidden categories
1338                 foreach ( $res as $row ) {
1339                         if ( isset( $row->pp_value ) ) {
1340                                 $categories[$row->page_title] = 'hidden';
1341                         }
1342                 }
1343
1344                 // Avoid PHP 7.1 warning of passing $this by reference
1345                 $outputPage = $this;
1346                 # Add the remaining categories to the skin
1347                 if ( Hooks::run(
1348                         'OutputPageMakeCategoryLinks',
1349                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1350                 ) {
1351                         $services = MediaWikiServices::getInstance();
1352                         $linkRenderer = $services->getLinkRenderer();
1353                         foreach ( $categories as $category => $type ) {
1354                                 // array keys will cast numeric category names to ints, so cast back to string
1355                                 $category = (string)$category;
1356                                 $origcategory = $category;
1357                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1358                                 if ( !$title ) {
1359                                         continue;
1360                                 }
1361                                 $services->getContentLanguage()->findVariantLink( $category, $title, true );
1362                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1363                                         continue;
1364                                 }
1365                                 $text = $services->getContentLanguage()->convertHtml( $title->getText() );
1366                                 $this->mCategories[$type][] = $title->getText();
1367                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1368                         }
1369                 }
1370         }
1371
1372         /**
1373          * @param array $categories
1374          * @return bool|IResultWrapper
1375          */
1376         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1377                 # Add the links to a LinkBatch
1378                 $arr = [ NS_CATEGORY => $categories ];
1379                 $lb = new LinkBatch;
1380                 $lb->setArray( $arr );
1381
1382                 # Fetch existence plus the hiddencat property
1383                 $dbr = wfGetDB( DB_REPLICA );
1384                 $fields = array_merge(
1385                         LinkCache::getSelectFields(),
1386                         [ 'page_namespace', 'page_title', 'pp_value' ]
1387                 );
1388
1389                 $res = $dbr->select( [ 'page', 'page_props' ],
1390                         $fields,
1391                         $lb->constructSet( 'page', $dbr ),
1392                         __METHOD__,
1393                         [],
1394                         [ 'page_props' => [ 'LEFT JOIN', [
1395                                 'pp_propname' => 'hiddencat',
1396                                 'pp_page = page_id'
1397                         ] ] ]
1398                 );
1399
1400                 # Add the results to the link cache
1401                 $linkCache = MediaWikiServices::getInstance()->getLinkCache();
1402                 $lb->addResultToCache( $linkCache, $res );
1403
1404                 return $res;
1405         }
1406
1407         /**
1408          * Reset the category links (but not the category list) and add $categories
1409          *
1410          * @param array $categories Mapping category name => sort key
1411          */
1412         public function setCategoryLinks( array $categories ) {
1413                 $this->mCategoryLinks = [];
1414                 $this->addCategoryLinks( $categories );
1415         }
1416
1417         /**
1418          * Get the list of category links, in a 2-D array with the following format:
1419          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1420          * hidden categories) and $link a HTML fragment with a link to the category
1421          * page
1422          *
1423          * @return array
1424          */
1425         public function getCategoryLinks() {
1426                 return $this->mCategoryLinks;
1427         }
1428
1429         /**
1430          * Get the list of category names this page belongs to.
1431          *
1432          * @param string $type The type of categories which should be returned. Possible values:
1433          *  * all: all categories of all types
1434          *  * hidden: only the hidden categories
1435          *  * normal: all categories, except hidden categories
1436          * @return array Array of strings
1437          */
1438         public function getCategories( $type = 'all' ) {
1439                 if ( $type === 'all' ) {
1440                         $allCategories = [];
1441                         foreach ( $this->mCategories as $categories ) {
1442                                 $allCategories = array_merge( $allCategories, $categories );
1443                         }
1444                         return $allCategories;
1445                 }
1446                 if ( !isset( $this->mCategories[$type] ) ) {
1447                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1448                 }
1449                 return $this->mCategories[$type];
1450         }
1451
1452         /**
1453          * Add an array of indicators, with their identifiers as array
1454          * keys and HTML contents as values.
1455          *
1456          * In case of duplicate keys, existing values are overwritten.
1457          *
1458          * @param array $indicators
1459          * @since 1.25
1460          */
1461         public function setIndicators( array $indicators ) {
1462                 $this->mIndicators = $indicators + $this->mIndicators;
1463                 // Keep ordered by key
1464                 ksort( $this->mIndicators );
1465         }
1466
1467         /**
1468          * Get the indicators associated with this page.
1469          *
1470          * The array will be internally ordered by item keys.
1471          *
1472          * @return array Keys: identifiers, values: HTML contents
1473          * @since 1.25
1474          */
1475         public function getIndicators() {
1476                 return $this->mIndicators;
1477         }
1478
1479         /**
1480          * Adds help link with an icon via page indicators.
1481          * Link target can be overridden by a local message containing a wikilink:
1482          * the message key is: lowercase action or special page name + '-helppage'.
1483          * @param string $to Target MediaWiki.org page title or encoded URL.
1484          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1485          * @since 1.25
1486          */
1487         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1488                 $this->addModuleStyles( 'mediawiki.helplink' );
1489                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1490
1491                 if ( $overrideBaseUrl ) {
1492                         $helpUrl = $to;
1493                 } else {
1494                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1495                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1496                 }
1497
1498                 $link = Html::rawElement(
1499                         'a',
1500                         [
1501                                 'href' => $helpUrl,
1502                                 'target' => '_blank',
1503                                 'class' => 'mw-helplink',
1504                         ],
1505                         $text
1506                 );
1507
1508                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1509         }
1510
1511         /**
1512          * Do not allow scripts which can be modified by wiki users to load on this page;
1513          * only allow scripts bundled with, or generated by, the software.
1514          * Site-wide styles are controlled by a config setting, since they can be
1515          * used to create a custom skin/theme, but not user-specific ones.
1516          *
1517          * @todo this should be given a more accurate name
1518          */
1519         public function disallowUserJs() {
1520                 $this->reduceAllowedModules(
1521                         ResourceLoaderModule::TYPE_SCRIPTS,
1522                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1523                 );
1524
1525                 // Site-wide styles are controlled by a config setting, see T73621
1526                 // for background on why. User styles are never allowed.
1527                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1528                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1529                 } else {
1530                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1531                 }
1532                 $this->reduceAllowedModules(
1533                         ResourceLoaderModule::TYPE_STYLES,
1534                         $styleOrigin
1535                 );
1536         }
1537
1538         /**
1539          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1540          * @see ResourceLoaderModule::$origin
1541          * @param string $type ResourceLoaderModule TYPE_ constant
1542          * @return int ResourceLoaderModule ORIGIN_ class constant
1543          */
1544         public function getAllowedModules( $type ) {
1545                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1546                         return min( array_values( $this->mAllowedModules ) );
1547                 } else {
1548                         return $this->mAllowedModules[$type] ?? ResourceLoaderModule::ORIGIN_ALL;
1549                 }
1550         }
1551
1552         /**
1553          * Limit the highest level of CSS/JS untrustworthiness allowed.
1554          *
1555          * If passed the same or a higher level than the current level of untrustworthiness set, the
1556          * level will remain unchanged.
1557          *
1558          * @param string $type
1559          * @param int $level ResourceLoaderModule class constant
1560          */
1561         public function reduceAllowedModules( $type, $level ) {
1562                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1563         }
1564
1565         /**
1566          * Prepend $text to the body HTML
1567          *
1568          * @param string $text HTML
1569          */
1570         public function prependHTML( $text ) {
1571                 $this->mBodytext = $text . $this->mBodytext;
1572         }
1573
1574         /**
1575          * Append $text to the body HTML
1576          *
1577          * @param string $text HTML
1578          */
1579         public function addHTML( $text ) {
1580                 $this->mBodytext .= $text;
1581         }
1582
1583         /**
1584          * Shortcut for adding an Html::element via addHTML.
1585          *
1586          * @since 1.19
1587          *
1588          * @param string $element
1589          * @param array $attribs
1590          * @param string $contents
1591          */
1592         public function addElement( $element, array $attribs = [], $contents = '' ) {
1593                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1594         }
1595
1596         /**
1597          * Clear the body HTML
1598          */
1599         public function clearHTML() {
1600                 $this->mBodytext = '';
1601         }
1602
1603         /**
1604          * Get the body HTML
1605          *
1606          * @return string HTML
1607          */
1608         public function getHTML() {
1609                 return $this->mBodytext;
1610         }
1611
1612         /**
1613          * Get/set the ParserOptions object to use for wikitext parsing
1614          *
1615          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1616          *   current ParserOption object. This parameter is deprecated since 1.31.
1617          * @return ParserOptions
1618          */
1619         public function parserOptions( $options = null ) {
1620                 if ( $options !== null ) {
1621                         wfDeprecated( __METHOD__ . ' with non-null $options', '1.31' );
1622                 }
1623
1624                 if ( $options !== null && !empty( $options->isBogus ) ) {
1625                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1626                         // been changed somehow, and keep it if so.
1627                         $anonPO = ParserOptions::newFromAnon();
1628                         $anonPO->setAllowUnsafeRawHtml( false );
1629                         if ( !$options->matches( $anonPO ) ) {
1630                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1631                                 $options->isBogus = false;
1632                         }
1633                 }
1634
1635                 if ( !$this->mParserOptions ) {
1636                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1637                                 // $wgUser isn't unstubbable yet, so don't try to get a
1638                                 // ParserOptions for it. And don't cache this ParserOptions
1639                                 // either.
1640                                 $po = ParserOptions::newFromAnon();
1641                                 $po->setAllowUnsafeRawHtml( false );
1642                                 $po->isBogus = true;
1643                                 if ( $options !== null ) {
1644                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1645                                 }
1646                                 return $po;
1647                         }
1648
1649                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1650                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1651                 }
1652
1653                 if ( $options !== null && !empty( $options->isBogus ) ) {
1654                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1655                         // thing.
1656                         return wfSetVar( $this->mParserOptions, null, true );
1657                 } else {
1658                         return wfSetVar( $this->mParserOptions, $options );
1659                 }
1660         }
1661
1662         /**
1663          * Set the revision ID which will be seen by the wiki text parser
1664          * for things such as embedded {{REVISIONID}} variable use.
1665          *
1666          * @param int|null $revid A positive integer, or null
1667          * @return mixed Previous value
1668          */
1669         public function setRevisionId( $revid ) {
1670                 $val = is_null( $revid ) ? null : intval( $revid );
1671                 return wfSetVar( $this->mRevisionId, $val, true );
1672         }
1673
1674         /**
1675          * Get the displayed revision ID
1676          *
1677          * @return int
1678          */
1679         public function getRevisionId() {
1680                 return $this->mRevisionId;
1681         }
1682
1683         /**
1684          * Set the timestamp of the revision which will be displayed. This is used
1685          * to avoid a extra DB call in Skin::lastModified().
1686          *
1687          * @param string|null $timestamp
1688          * @return mixed Previous value
1689          */
1690         public function setRevisionTimestamp( $timestamp ) {
1691                 return wfSetVar( $this->mRevisionTimestamp, $timestamp, true );
1692         }
1693
1694         /**
1695          * Get the timestamp of displayed revision.
1696          * This will be null if not filled by setRevisionTimestamp().
1697          *
1698          * @return string|null
1699          */
1700         public function getRevisionTimestamp() {
1701                 return $this->mRevisionTimestamp;
1702         }
1703
1704         /**
1705          * Set the displayed file version
1706          *
1707          * @param File|null $file
1708          * @return mixed Previous value
1709          */
1710         public function setFileVersion( $file ) {
1711                 $val = null;
1712                 if ( $file instanceof File && $file->exists() ) {
1713                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1714                 }
1715                 return wfSetVar( $this->mFileVersion, $val, true );
1716         }
1717
1718         /**
1719          * Get the displayed file version
1720          *
1721          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1722          */
1723         public function getFileVersion() {
1724                 return $this->mFileVersion;
1725         }
1726
1727         /**
1728          * Get the templates used on this page
1729          *
1730          * @return array (namespace => dbKey => revId)
1731          * @since 1.18
1732          */
1733         public function getTemplateIds() {
1734                 return $this->mTemplateIds;
1735         }
1736
1737         /**
1738          * Get the files used on this page
1739          *
1740          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1741          * @since 1.18
1742          */
1743         public function getFileSearchOptions() {
1744                 return $this->mImageTimeKeys;
1745         }
1746
1747         /**
1748          * Convert wikitext to HTML and add it to the buffer
1749          * Default assumes that the current page title will be used.
1750          *
1751          * @param string $text
1752          * @param bool $linestart Is this the start of a line?
1753          * @param bool $interface Is this text in the user interface language?
1754          * @throws MWException
1755          * @deprecated since 1.32 due to untidy output; use
1756          *    addWikiTextAsInterface() if $interface is default value or true,
1757          *    or else addWikiTextAsContent() if $interface is false.
1758          */
1759         public function addWikiText( $text, $linestart = true, $interface = true ) {
1760                 wfDeprecated( __METHOD__, '1.32' );
1761                 $title = $this->getTitle();
1762                 if ( !$title ) {
1763                         throw new MWException( 'Title is null' );
1764                 }
1765                 $this->addWikiTextTitleInternal( $text, $title, $linestart, /*tidy*/false, $interface );
1766         }
1767
1768         /**
1769          * Convert wikitext *in the user interface language* to HTML and
1770          * add it to the buffer. The result will not be
1771          * language-converted, as user interface messages are already
1772          * localized into a specific variant.  Assumes that the current
1773          * page title will be used if optional $title is not
1774          * provided. Output will be tidy.
1775          *
1776          * @param string $text Wikitext in the user interface language
1777          * @param bool $linestart Is this the start of a line? (Defaults to true)
1778          * @param Title|null $title Optional title to use; default of `null`
1779          *   means use current page title.
1780          * @throws MWException if $title is not provided and OutputPage::getTitle()
1781          *   is null
1782          * @since 1.32
1783          */
1784         public function addWikiTextAsInterface(
1785                 $text, $linestart = true, Title $title = null
1786         ) {
1787                 if ( $title === null ) {
1788                         $title = $this->getTitle();
1789                 }
1790                 if ( !$title ) {
1791                         throw new MWException( 'Title is null' );
1792                 }
1793                 $this->addWikiTextTitleInternal( $text, $title, $linestart, /*tidy*/true, /*interface*/true );
1794         }
1795
1796         /**
1797          * Convert wikitext *in the user interface language* to HTML and
1798          * add it to the buffer with a `<div class="$wrapperClass">`
1799          * wrapper.  The result will not be language-converted, as user
1800          * interface messages as already localized into a specific
1801          * variant.  The $text will be parsed in start-of-line context.
1802          * Output will be tidy.
1803          *
1804          * @param string $wrapperClass The class attribute value for the <div>
1805          *   wrapper in the output HTML
1806          * @param string $text Wikitext in the user interface language
1807          * @since 1.32
1808          */
1809         public function wrapWikiTextAsInterface(
1810                 $wrapperClass, $text
1811         ) {
1812                 $this->addWikiTextTitleInternal(
1813                         $text, $this->getTitle(),
1814                         /*linestart*/true, /*tidy*/true, /*interface*/true,
1815                         $wrapperClass
1816                 );
1817         }
1818
1819         /**
1820          * Convert wikitext *in the page content language* to HTML and add
1821          * it to the buffer.  The result with be language-converted to the
1822          * user's preferred variant.  Assumes that the current page title
1823          * will be used if optional $title is not provided. Output will be
1824          * tidy.
1825          *
1826          * @param string $text Wikitext in the page content language
1827          * @param bool $linestart Is this the start of a line? (Defaults to true)
1828          * @param Title|null $title Optional title to use; default of `null`
1829          *   means use current page title.
1830          * @throws MWException if $title is not provided and OutputPage::getTitle()
1831          *   is null
1832          * @since 1.32
1833          */
1834         public function addWikiTextAsContent(
1835                 $text, $linestart = true, Title $title = null
1836         ) {
1837                 if ( $title === null ) {
1838                         $title = $this->getTitle();
1839                 }
1840                 if ( !$title ) {
1841                         throw new MWException( 'Title is null' );
1842                 }
1843                 $this->addWikiTextTitleInternal( $text, $title, $linestart, /*tidy*/true, /*interface*/false );
1844         }
1845
1846         /**
1847          * Add wikitext with a custom Title object
1848          *
1849          * @param string $text Wikitext
1850          * @param Title $title
1851          * @param bool $linestart Is this the start of a line?
1852          * @deprecated since 1.32 due to untidy output; use
1853          *   addWikiTextAsInterface()
1854          */
1855         public function addWikiTextWithTitle( $text, Title $title, $linestart = true ) {
1856                 wfDeprecated( __METHOD__, '1.32' );
1857                 $this->addWikiTextTitleInternal( $text, $title, $linestart, /*tidy*/false, /*interface*/false );
1858         }
1859
1860         /**
1861          * Add wikitext *in content language* with a custom Title object.
1862          * Output will be tidy.
1863          *
1864          * @param string $text Wikitext in content language
1865          * @param Title $title
1866          * @param bool $linestart Is this the start of a line?
1867          * @deprecated since 1.32 to rename methods consistently; use
1868          *   addWikiTextAsContent()
1869          */
1870         function addWikiTextTitleTidy( $text, Title $title, $linestart = true ) {
1871                 wfDeprecated( __METHOD__, '1.32' );
1872                 $this->addWikiTextTitleInternal( $text, $title, $linestart, /*tidy*/true, /*interface*/false );
1873         }
1874
1875         /**
1876          * Add wikitext *in content language*. Output will be tidy.
1877          *
1878          * @param string $text Wikitext in content language
1879          * @param bool $linestart Is this the start of a line?
1880          * @deprecated since 1.32 to rename methods consistently; use
1881          *   addWikiTextAsContent()
1882          */
1883         public function addWikiTextTidy( $text, $linestart = true ) {
1884                 wfDeprecated( __METHOD__, '1.32' );
1885                 $title = $this->getTitle();
1886                 if ( !$title ) {
1887                         throw new MWException( 'Title is null' );
1888                 }
1889                 $this->addWikiTextTitleInternal( $text, $title, $linestart, /*tidy*/true, /*interface*/false );
1890         }
1891
1892         /**
1893          * Add wikitext with a custom Title object.
1894          * Output is unwrapped.
1895          *
1896          * @param string $text Wikitext
1897          * @param Title $title
1898          * @param bool $linestart Is this the start of a line?
1899          * @param bool $tidy Whether to use tidy.
1900          *             Setting this to false (or omitting it) is deprecated
1901          *             since 1.32; all wikitext should be tidied.
1902          *             For backwards-compatibility with prior MW releases,
1903          *             you may wish to invoke this method but set $tidy=true;
1904          *             this will result in equivalent output to the non-deprecated
1905          *             addWikiTextAsContent()/addWikiTextAsInterface() methods.
1906          * @param bool $interface Whether it is an interface message
1907          *   (for example disables conversion)
1908          * @deprecated since 1.32, use addWikiTextAsContent() or
1909          *   addWikiTextAsInterface() (depending on $interface)
1910          */
1911         public function addWikiTextTitle( $text, Title $title, $linestart,
1912                 $tidy = false, $interface = false
1913         ) {
1914                 wfDeprecated( __METHOD__, '1.32' );
1915                 return $this->addWikiTextTitleInternal( $text, $title, $linestart, $tidy, $interface );
1916         }
1917
1918         /**
1919          * Add wikitext with a custom Title object.
1920          * Output is unwrapped.
1921          *
1922          * @param string $text Wikitext
1923          * @param Title $title
1924          * @param bool $linestart Is this the start of a line?
1925          * @param bool $tidy Whether to use tidy.
1926          *             Setting this to false (or omitting it) is deprecated
1927          *             since 1.32; all wikitext should be tidied.
1928          * @param bool $interface Whether it is an interface message
1929          *   (for example disables conversion)
1930          * @param string $wrapperClass if not empty, wraps the output in
1931          *   a `<div class="$wrapperClass">`
1932          * @private
1933          */
1934         private function addWikiTextTitleInternal(
1935                 $text, Title $title, $linestart, $tidy, $interface, $wrapperClass = null
1936         ) {
1937                 if ( !$tidy ) {
1938                         wfDeprecated( 'disabling tidy', '1.32' );
1939                 }
1940
1941                 $parserOutput = $this->parseInternal(
1942                         $text, $title, $linestart, $tidy, $interface, /*language*/null
1943                 );
1944
1945                 $this->addParserOutput( $parserOutput, [
1946                         'enableSectionEditLinks' => false,
1947                         'wrapperDivClass' => $wrapperClass ?? '',
1948                 ] );
1949         }
1950
1951         /**
1952          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1953          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1954          * and so on.
1955          *
1956          * @since 1.24
1957          * @param ParserOutput $parserOutput
1958          */
1959         public function addParserOutputMetadata( ParserOutput $parserOutput ) {
1960                 $this->mLanguageLinks =
1961                         array_merge( $this->mLanguageLinks, $parserOutput->getLanguageLinks() );
1962                 $this->addCategoryLinks( $parserOutput->getCategories() );
1963                 $this->setIndicators( $parserOutput->getIndicators() );
1964                 $this->mNewSectionLink = $parserOutput->getNewSection();
1965                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1966
1967                 if ( !$parserOutput->isCacheable() ) {
1968                         $this->enableClientCache( false );
1969                 }
1970                 $this->mNoGallery = $parserOutput->getNoGallery();
1971                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1972                 $this->addModules( $parserOutput->getModules() );
1973                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1974                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1975                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1976                 $this->mPreventClickjacking = $this->mPreventClickjacking
1977                         || $parserOutput->preventClickjacking();
1978
1979                 // Template versioning...
1980                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1981                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1982                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1983                         } else {
1984                                 $this->mTemplateIds[$ns] = $dbks;
1985                         }
1986                 }
1987                 // File versioning...
1988                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1989                         $this->mImageTimeKeys[$dbk] = $data;
1990                 }
1991
1992                 // Hooks registered in the object
1993                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1994                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1995                         list( $hookName, $data ) = $hookInfo;
1996                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1997                                 $parserOutputHooks[$hookName]( $this, $parserOutput, $data );
1998                         }
1999                 }
2000
2001                 // Enable OOUI if requested via ParserOutput
2002                 if ( $parserOutput->getEnableOOUI() ) {
2003                         $this->enableOOUI();
2004                 }
2005
2006                 // Include parser limit report
2007                 if ( !$this->limitReportJSData ) {
2008                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
2009                 }
2010
2011                 // Link flags are ignored for now, but may in the future be
2012                 // used to mark individual language links.
2013                 $linkFlags = [];
2014                 // Avoid PHP 7.1 warning of passing $this by reference
2015                 $outputPage = $this;
2016                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
2017                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
2018
2019                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
2020                 // so that extensions may modify ParserOutput to toggle TOC.
2021                 // This cannot be moved to addParserOutputText because that is not
2022                 // called by EditPage for Preview.
2023                 if ( $parserOutput->getTOCHTML() ) {
2024                         $this->mEnableTOC = true;
2025                 }
2026         }
2027
2028         /**
2029          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
2030          * ParserOutput object, without any other metadata.
2031          *
2032          * @since 1.24
2033          * @param ParserOutput $parserOutput
2034          * @param array $poOptions Options to ParserOutput::getText()
2035          */
2036         public function addParserOutputContent( ParserOutput $parserOutput, $poOptions = [] ) {
2037                 $this->addParserOutputText( $parserOutput, $poOptions );
2038
2039                 $this->addModules( $parserOutput->getModules() );
2040                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
2041                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
2042
2043                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
2044         }
2045
2046         /**
2047          * Add the HTML associated with a ParserOutput object, without any metadata.
2048          *
2049          * @since 1.24
2050          * @param ParserOutput $parserOutput
2051          * @param array $poOptions Options to ParserOutput::getText()
2052          */
2053         public function addParserOutputText( ParserOutput $parserOutput, $poOptions = [] ) {
2054                 $text = $parserOutput->getText( $poOptions );
2055                 // Avoid PHP 7.1 warning of passing $this by reference
2056                 $outputPage = $this;
2057                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
2058                 $this->addHTML( $text );
2059         }
2060
2061         /**
2062          * Add everything from a ParserOutput object.
2063          *
2064          * @param ParserOutput $parserOutput
2065          * @param array $poOptions Options to ParserOutput::getText()
2066          */
2067         function addParserOutput( ParserOutput $parserOutput, $poOptions = [] ) {
2068                 $this->addParserOutputMetadata( $parserOutput );
2069                 $this->addParserOutputText( $parserOutput, $poOptions );
2070         }
2071
2072         /**
2073          * Add the output of a QuickTemplate to the output buffer
2074          *
2075          * @param QuickTemplate &$template
2076          */
2077         public function addTemplate( &$template ) {
2078                 $this->addHTML( $template->getHTML() );
2079         }
2080
2081         /**
2082          * Parse wikitext and return the HTML.
2083          *
2084          * @todo The output is wrapped in a <div> iff $interface is false; it's
2085          * probably best to always strip the wrapper.
2086          *
2087          * @param string $text
2088          * @param bool $linestart Is this the start of a line?
2089          * @param bool $interface Use interface language (instead of content language) while parsing
2090          *   language sensitive magic words like GRAMMAR and PLURAL.  This also disables
2091          *   LanguageConverter.
2092          * @param Language|null $language Target language object, will override $interface
2093          * @throws MWException
2094          * @return string HTML
2095          * @deprecated since 1.32, due to untidy output and inconsistent wrapper;
2096          *  use parseAsContent() if $interface is default value or false, or else
2097          *  parseAsInterface() if $interface is true.
2098          */
2099         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
2100                 wfDeprecated( __METHOD__, '1.33' );
2101                 return $this->parseInternal(
2102                         $text, $this->getTitle(), $linestart, /*tidy*/false, $interface, $language
2103                 )->getText( [
2104                         'enableSectionEditLinks' => false,
2105                 ] );
2106         }
2107
2108         /**
2109          * Parse wikitext *in the page content language* and return the HTML.
2110          * The result will be language-converted to the user's preferred variant.
2111          * Output will be tidy.
2112          *
2113          * @param string $text Wikitext in the page content language
2114          * @param bool $linestart Is this the start of a line? (Defaults to true)
2115          * @throws MWException
2116          * @return string HTML
2117          * @since 1.32
2118          */
2119         public function parseAsContent( $text, $linestart = true ) {
2120                 return $this->parseInternal(
2121                         $text, $this->getTitle(), $linestart, /*tidy*/true, /*interface*/false, /*language*/null
2122                 )->getText( [
2123                         'enableSectionEditLinks' => false,
2124                         'wrapperDivClass' => ''
2125                 ] );
2126         }
2127
2128         /**
2129          * Parse wikitext *in the user interface language* and return the HTML.
2130          * The result will not be language-converted, as user interface messages
2131          * are already localized into a specific variant.
2132          * Output will be tidy.
2133          *
2134          * @param string $text Wikitext in the user interface language
2135          * @param bool $linestart Is this the start of a line? (Defaults to true)
2136          * @throws MWException
2137          * @return string HTML
2138          * @since 1.32
2139          */
2140         public function parseAsInterface( $text, $linestart = true ) {
2141                 return $this->parseInternal(
2142                         $text, $this->getTitle(), $linestart, /*tidy*/true, /*interface*/true, /*language*/null
2143                 )->getText( [
2144                         'enableSectionEditLinks' => false,
2145                         'wrapperDivClass' => ''
2146                 ] );
2147         }
2148
2149         /**
2150          * Parse wikitext *in the user interface language*, strip
2151          * paragraph wrapper, and return the HTML.
2152          * The result will not be language-converted, as user interface messages
2153          * are already localized into a specific variant.
2154          * Output will be tidy.  Outer paragraph wrapper will only be stripped
2155          * if the result is a single paragraph.
2156          *
2157          * @param string $text Wikitext in the user interface language
2158          * @param bool $linestart Is this the start of a line? (Defaults to true)
2159          * @throws MWException
2160          * @return string HTML
2161          * @since 1.32
2162          */
2163         public function parseInlineAsInterface( $text, $linestart = true ) {
2164                 return Parser::stripOuterParagraph(
2165                         $this->parseAsInterface( $text, $linestart )
2166                 );
2167         }
2168
2169         /**
2170          * Parse wikitext, strip paragraph wrapper, and return the HTML.
2171          *
2172          * @param string $text
2173          * @param bool $linestart Is this the start of a line?
2174          * @param bool $interface Use interface language (instead of content language) while parsing
2175          *   language sensitive magic words like GRAMMAR and PLURAL
2176          * @return string HTML
2177          * @deprecated since 1.32, due to untidy output and confusing default
2178          *   for $interface.  Use parseInlineAsInterface() if $interface is
2179          *   the default value or false, or else use
2180          *   Parser::stripOuterParagraph($outputPage->parseAsContent(...)).
2181          */
2182         public function parseInline( $text, $linestart = true, $interface = false ) {
2183                 wfDeprecated( __METHOD__, '1.33' );
2184                 $parsed = $this->parseInternal(
2185                         $text, $this->getTitle(), $linestart, /*tidy*/false, $interface, /*language*/null
2186                 )->getText( [
2187                         'enableSectionEditLinks' => false,
2188                         'wrapperDivClass' => '', /* no wrapper div */
2189                 ] );
2190                 return Parser::stripOuterParagraph( $parsed );
2191         }
2192
2193         /**
2194          * Parse wikitext and return the HTML (internal implementation helper)
2195          *
2196          * @param string $text
2197          * @param Title The title to use
2198          * @param bool $linestart Is this the start of a line?
2199          * @param bool $tidy Whether the output should be tidied
2200          * @param bool $interface Use interface language (instead of content language) while parsing
2201          *   language sensitive magic words like GRAMMAR and PLURAL.  This also disables
2202          *   LanguageConverter.
2203          * @param Language|null $language Target language object, will override $interface
2204          * @throws MWException
2205          * @return ParserOutput
2206          */
2207         private function parseInternal( $text, $title, $linestart, $tidy, $interface, $language ) {
2208                 global $wgParser;
2209
2210                 if ( is_null( $title ) ) {
2211                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
2212                 }
2213
2214                 $popts = $this->parserOptions();
2215                 $oldTidy = $popts->setTidy( $tidy );
2216                 $oldInterface = $popts->setInterfaceMessage( (bool)$interface );
2217
2218                 if ( $language !== null ) {
2219                         $oldLang = $popts->setTargetLanguage( $language );
2220                 }
2221
2222                 $parserOutput = $wgParser->getFreshParser()->parse(
2223                         $text, $title, $popts,
2224                         $linestart, true, $this->mRevisionId
2225                 );
2226
2227                 $popts->setTidy( $oldTidy );
2228                 $popts->setInterfaceMessage( $oldInterface );
2229
2230                 if ( $language !== null ) {
2231                         $popts->setTargetLanguage( $oldLang );
2232                 }
2233
2234                 return $parserOutput;
2235         }
2236
2237         /**
2238          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
2239          *
2240          * @param int $maxage Maximum cache time on the CDN, in seconds.
2241          */
2242         public function setCdnMaxage( $maxage ) {
2243                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
2244         }
2245
2246         /**
2247          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header to $maxage if that is
2248          * lower than the current s-maxage.  Either way, $maxage is now an upper limit on s-maxage, so
2249          * that future calls to setCdnMaxage() will no longer be able to raise the s-maxage above
2250          * $maxage.
2251          *
2252          * @param int $maxage Maximum cache time on the CDN, in seconds
2253          * @since 1.27
2254          */
2255         public function lowerCdnMaxage( $maxage ) {
2256                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
2257                 $this->setCdnMaxage( $this->mCdnMaxage );
2258         }
2259
2260         /**
2261          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
2262          *
2263          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
2264          * the TTL is higher the older the $mtime timestamp is. Essentially, the
2265          * TTL is 90% of the age of the object, subject to the min and max.
2266          *
2267          * @param string|int|float|bool|null $mtime Last-Modified timestamp
2268          * @param int $minTTL Minimum TTL in seconds [default: 1 minute]
2269          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
2270          * @since 1.28
2271          */
2272         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
2273                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
2274                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
2275
2276                 if ( $mtime === null || $mtime === false ) {
2277                         return $minTTL; // entity does not exist
2278                 }
2279
2280                 $age = MWTimestamp::time() - wfTimestamp( TS_UNIX, $mtime );
2281                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
2282                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
2283
2284                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2285         }
2286
2287         /**
2288          * Use enableClientCache(false) to force it to send nocache headers
2289          *
2290          * @param bool|null $state New value, or null to not set the value
2291          *
2292          * @return bool Old value
2293          */
2294         public function enableClientCache( $state ) {
2295                 return wfSetVar( $this->mEnableClientCache, $state );
2296         }
2297
2298         /**
2299          * Get the list of cookie names that will influence the cache
2300          *
2301          * @return array
2302          */
2303         function getCacheVaryCookies() {
2304                 if ( self::$cacheVaryCookies === null ) {
2305                         $config = $this->getConfig();
2306                         self::$cacheVaryCookies = array_values( array_unique( array_merge(
2307                                 SessionManager::singleton()->getVaryCookies(),
2308                                 [
2309                                         'forceHTTPS',
2310                                 ],
2311                                 $config->get( 'CacheVaryCookies' )
2312                         ) ) );
2313                         Hooks::run( 'GetCacheVaryCookies', [ $this, &self::$cacheVaryCookies ] );
2314                 }
2315                 return self::$cacheVaryCookies;
2316         }
2317
2318         /**
2319          * Check if the request has a cache-varying cookie header
2320          * If it does, it's very important that we don't allow public caching
2321          *
2322          * @return bool
2323          */
2324         function haveCacheVaryCookies() {
2325                 $request = $this->getRequest();
2326                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2327                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2328                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2329                                 return true;
2330                         }
2331                 }
2332                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2333                 return false;
2334         }
2335
2336         /**
2337          * Add an HTTP header that will influence on the cache
2338          *
2339          * @param string $header Header name
2340          * @param string[]|null $option Options for the Key header. See
2341          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2342          * for the list of valid options.
2343          */
2344         public function addVaryHeader( $header, array $option = null ) {
2345                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2346                         $this->mVaryHeader[$header] = [];
2347                 }
2348                 if ( !is_array( $option ) ) {
2349                         $option = [];
2350                 }
2351                 $this->mVaryHeader[$header] =
2352                         array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2353         }
2354
2355         /**
2356          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2357          * such as Accept-Encoding or Cookie
2358          *
2359          * @return string
2360          */
2361         public function getVaryHeader() {
2362                 // If we vary on cookies, let's make sure it's always included here too.
2363                 if ( $this->getCacheVaryCookies() ) {
2364                         $this->addVaryHeader( 'Cookie' );
2365                 }
2366
2367                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2368                         $this->addVaryHeader( $header, $options );
2369                 }
2370                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2371         }
2372
2373         /**
2374          * Add an HTTP Link: header
2375          *
2376          * @param string $header Header value
2377          */
2378         public function addLinkHeader( $header ) {
2379                 $this->mLinkHeader[] = $header;
2380         }
2381
2382         /**
2383          * Return a Link: header. Based on the values of $mLinkHeader.
2384          *
2385          * @return string
2386          */
2387         public function getLinkHeader() {
2388                 if ( !$this->mLinkHeader ) {
2389                         return false;
2390                 }
2391
2392                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2393         }
2394
2395         /**
2396          * Get a complete Key header
2397          *
2398          * @return string
2399          * @deprecated in 1.32; the IETF spec for this header expired w/o becoming
2400          *   a standard.
2401          */
2402         public function getKeyHeader() {
2403                 wfDeprecated( '$wgUseKeyHeader', '1.32' );
2404
2405                 $cvCookies = $this->getCacheVaryCookies();
2406
2407                 $cookiesOption = [];
2408                 foreach ( $cvCookies as $cookieName ) {
2409                         $cookiesOption[] = 'param=' . $cookieName;
2410                 }
2411                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2412
2413                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2414                         $this->addVaryHeader( $header, $options );
2415                 }
2416
2417                 $headers = [];
2418                 foreach ( $this->mVaryHeader as $header => $option ) {
2419                         $newheader = $header;
2420                         if ( is_array( $option ) && count( $option ) > 0 ) {
2421                                 $newheader .= ';' . implode( ';', $option );
2422                         }
2423                         $headers[] = $newheader;
2424                 }
2425                 $key = 'Key: ' . implode( ',', $headers );
2426
2427                 return $key;
2428         }
2429
2430         /**
2431          * T23672: Add Accept-Language to Vary and Key headers if there's no 'variant' parameter in GET.
2432          *
2433          * For example:
2434          *   /w/index.php?title=Main_page will vary based on Accept-Language; but
2435          *   /w/index.php?title=Main_page&variant=zh-cn will not.
2436          */
2437         private function addAcceptLanguage() {
2438                 $title = $this->getTitle();
2439                 if ( !$title instanceof Title ) {
2440                         return;
2441                 }
2442
2443                 $lang = $title->getPageLanguage();
2444                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2445                         $variants = $lang->getVariants();
2446                         $aloption = [];
2447                         foreach ( $variants as $variant ) {
2448                                 if ( $variant === $lang->getCode() ) {
2449                                         continue;
2450                                 }
2451
2452                                 // XXX Note that this code is not strictly correct: we
2453                                 // do a case-insensitive match in
2454                                 // LanguageConverter::getHeaderVariant() while the
2455                                 // (abandoned, draft) spec for the `Key` header only
2456                                 // allows case-sensitive matches.  To match the logic
2457                                 // in LanguageConverter::getHeaderVariant() we should
2458                                 // also be looking at fallback variants and deprecated
2459                                 // mediawiki-internal codes, as well as BCP 47
2460                                 // normalized forms.
2461
2462                                 $aloption[] = "substr=$variant";
2463
2464                                 // IE and some other browsers use BCP 47 standards in their Accept-Language header,
2465                                 // like "zh-CN" or "zh-Hant".  We should handle these too.
2466                                 $variantBCP47 = LanguageCode::bcp47( $variant );
2467                                 if ( $variantBCP47 !== $variant ) {
2468                                         $aloption[] = "substr=$variantBCP47";
2469                                 }
2470                         }
2471                         $this->addVaryHeader( 'Accept-Language', $aloption );
2472                 }
2473         }
2474
2475         /**
2476          * Set a flag which will cause an X-Frame-Options header appropriate for
2477          * edit pages to be sent. The header value is controlled by
2478          * $wgEditPageFrameOptions.
2479          *
2480          * This is the default for special pages. If you display a CSRF-protected
2481          * form on an ordinary view page, then you need to call this function.
2482          *
2483          * @param bool $enable
2484          */
2485         public function preventClickjacking( $enable = true ) {
2486                 $this->mPreventClickjacking = $enable;
2487         }
2488
2489         /**
2490          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2491          * This can be called from pages which do not contain any CSRF-protected
2492          * HTML form.
2493          */
2494         public function allowClickjacking() {
2495                 $this->mPreventClickjacking = false;
2496         }
2497
2498         /**
2499          * Get the prevent-clickjacking flag
2500          *
2501          * @since 1.24
2502          * @return bool
2503          */
2504         public function getPreventClickjacking() {
2505                 return $this->mPreventClickjacking;
2506         }
2507
2508         /**
2509          * Get the X-Frame-Options header value (without the name part), or false
2510          * if there isn't one. This is used by Skin to determine whether to enable
2511          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2512          *
2513          * @return string|false
2514          */
2515         public function getFrameOptions() {
2516                 $config = $this->getConfig();
2517                 if ( $config->get( 'BreakFrames' ) ) {
2518                         return 'DENY';
2519                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2520                         return $config->get( 'EditPageFrameOptions' );
2521                 }
2522                 return false;
2523         }
2524
2525         /**
2526          * Send cache control HTTP headers
2527          */
2528         public function sendCacheControl() {
2529                 $response = $this->getRequest()->response();
2530                 $config = $this->getConfig();
2531
2532                 $this->addVaryHeader( 'Cookie' );
2533                 $this->addAcceptLanguage();
2534
2535                 # don't serve compressed data to clients who can't handle it
2536                 # maintain different caches for logged-in users and non-logged in ones
2537                 $response->header( $this->getVaryHeader() );
2538
2539                 if ( $config->get( 'UseKeyHeader' ) ) {
2540                         $response->header( $this->getKeyHeader() );
2541                 }
2542
2543                 if ( $this->mEnableClientCache ) {
2544                         if (
2545                                 $config->get( 'UseSquid' ) &&
2546                                 !$response->hasCookies() &&
2547                                 !SessionManager::getGlobalSession()->isPersistent() &&
2548                                 !$this->isPrintable() &&
2549                                 $this->mCdnMaxage != 0 &&
2550                                 !$this->haveCacheVaryCookies()
2551                         ) {
2552                                 if ( $config->get( 'UseESI' ) ) {
2553                                         wfDeprecated( '$wgUseESI = true', '1.33' );
2554                                         # We'll purge the proxy cache explicitly, but require end user agents
2555                                         # to revalidate against the proxy on each visit.
2556                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2557                                         wfDebug( __METHOD__ .
2558                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2559                                         # start with a shorter timeout for initial testing
2560                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2561                                         $response->header(
2562                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2563                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2564                                         );
2565                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2566                                 } else {
2567                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2568                                         # to revalidate against the proxy on each visit.
2569                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2570                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2571                                         wfDebug( __METHOD__ .
2572                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2573                                         # start with a shorter timeout for initial testing
2574                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2575                                         $response->header( "Cache-Control: " .
2576                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2577                                 }
2578                         } else {
2579                                 # We do want clients to cache if they can, but they *must* check for updates
2580                                 # on revisiting the page.
2581                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2582                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2583                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2584                         }
2585                         if ( $this->mLastModified ) {
2586                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2587                         }
2588                 } else {
2589                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2590
2591                         # In general, the absence of a last modified header should be enough to prevent
2592                         # the client from using its cache. We send a few other things just to make sure.
2593                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2594                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2595                         $response->header( 'Pragma: no-cache' );
2596                 }
2597         }
2598
2599         /**
2600          * Transfer styles and JavaScript modules from skin.
2601          *
2602          * @param Skin $sk to load modules for
2603          */
2604         public function loadSkinModules( $sk ) {
2605                 foreach ( $sk->getDefaultModules() as $group => $modules ) {
2606                         if ( $group === 'styles' ) {
2607                                 foreach ( $modules as $key => $moduleMembers ) {
2608                                         $this->addModuleStyles( $moduleMembers );
2609                                 }
2610                         } else {
2611                                 $this->addModules( $modules );
2612                         }
2613                 }
2614         }
2615
2616         /**
2617          * Finally, all the text has been munged and accumulated into
2618          * the object, let's actually output it:
2619          *
2620          * @param bool $return Set to true to get the result as a string rather than sending it
2621          * @return string|null
2622          * @throws Exception
2623          * @throws FatalError
2624          * @throws MWException
2625          */
2626         public function output( $return = false ) {
2627                 if ( $this->mDoNothing ) {
2628                         return $return ? '' : null;
2629                 }
2630
2631                 $response = $this->getRequest()->response();
2632                 $config = $this->getConfig();
2633
2634                 if ( $this->mRedirect != '' ) {
2635                         # Standards require redirect URLs to be absolute
2636                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2637
2638                         $redirect = $this->mRedirect;
2639                         $code = $this->mRedirectCode;
2640
2641                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2642                                 if ( $code == '301' || $code == '303' ) {
2643                                         if ( !$config->get( 'DebugRedirects' ) ) {
2644                                                 $response->statusHeader( $code );
2645                                         }
2646                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2647                                 }
2648                                 if ( $config->get( 'VaryOnXFP' ) ) {
2649                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2650                                 }
2651                                 $this->sendCacheControl();
2652
2653                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2654                                 if ( $config->get( 'DebugRedirects' ) ) {
2655                                         $url = htmlspecialchars( $redirect );
2656                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2657                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2658                                         print "</body>\n</html>\n";
2659                                 } else {
2660                                         $response->header( 'Location: ' . $redirect );
2661                                 }
2662                         }
2663
2664                         return $return ? '' : null;
2665                 } elseif ( $this->mStatusCode ) {
2666                         $response->statusHeader( $this->mStatusCode );
2667                 }
2668
2669                 # Buffer output; final headers may depend on later processing
2670                 ob_start();
2671
2672                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2673                 $response->header( 'Content-language: ' .
2674                         MediaWikiServices::getInstance()->getContentLanguage()->getHtmlCode() );
2675
2676                 if ( !$this->mArticleBodyOnly ) {
2677                         $sk = $this->getSkin();
2678                 }
2679
2680                 $linkHeader = $this->getLinkHeader();
2681                 if ( $linkHeader ) {
2682                         $response->header( $linkHeader );
2683                 }
2684
2685                 // Prevent framing, if requested
2686                 $frameOptions = $this->getFrameOptions();
2687                 if ( $frameOptions ) {
2688                         $response->header( "X-Frame-Options: $frameOptions" );
2689                 }
2690
2691                 ContentSecurityPolicy::sendHeaders( $this );
2692
2693                 if ( $this->mArticleBodyOnly ) {
2694                         echo $this->mBodytext;
2695                 } else {
2696                         // Enable safe mode if requested (T152169)
2697                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2698                                 $this->disallowUserJs();
2699                         }
2700
2701                         $sk = $this->getSkin();
2702                         $this->loadSkinModules( $sk );
2703
2704                         MWDebug::addModules( $this );
2705
2706                         // Avoid PHP 7.1 warning of passing $this by reference
2707                         $outputPage = $this;
2708                         // Hook that allows last minute changes to the output page, e.g.
2709                         // adding of CSS or Javascript by extensions.
2710                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2711
2712                         try {
2713                                 $sk->outputPage();
2714                         } catch ( Exception $e ) {
2715                                 ob_end_clean(); // bug T129657
2716                                 throw $e;
2717                         }
2718                 }
2719
2720                 try {
2721                         // This hook allows last minute changes to final overall output by modifying output buffer
2722                         Hooks::runWithoutAbort( 'AfterFinalPageOutput', [ $this ] );
2723                 } catch ( Exception $e ) {
2724                         ob_end_clean(); // bug T129657
2725                         throw $e;
2726                 }
2727
2728                 $this->sendCacheControl();
2729
2730                 if ( $return ) {
2731                         return ob_get_clean();
2732                 } else {
2733                         ob_end_flush();
2734                         return null;
2735                 }
2736         }
2737
2738         /**
2739          * Prepare this object to display an error page; disable caching and
2740          * indexing, clear the current text and redirect, set the page's title
2741          * and optionally an custom HTML title (content of the "<title>" tag).
2742          *
2743          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2744          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2745          *                   optional, if not passed the "<title>" attribute will be
2746          *                   based on $pageTitle
2747          */
2748         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2749                 $this->setPageTitle( $pageTitle );
2750                 if ( $htmlTitle !== false ) {
2751                         $this->setHTMLTitle( $htmlTitle );
2752                 }
2753                 $this->setRobotPolicy( 'noindex,nofollow' );
2754                 $this->setArticleRelated( false );
2755                 $this->enableClientCache( false );
2756                 $this->mRedirect = '';
2757                 $this->clearSubtitle();
2758                 $this->clearHTML();
2759         }
2760
2761         /**
2762          * Output a standard error page
2763          *
2764          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2765          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2766          * showErrorPage( 'titlemsg', $messageObject );
2767          * showErrorPage( $titleMessageObject, $messageObject );
2768          *
2769          * @param string|Message $title Message key (string) for page title, or a Message object
2770          * @param string|Message $msg Message key (string) for page text, or a Message object
2771          * @param array $params Message parameters; ignored if $msg is a Message object
2772          */
2773         public function showErrorPage( $title, $msg, $params = [] ) {
2774                 if ( !$title instanceof Message ) {
2775                         $title = $this->msg( $title );
2776                 }
2777
2778                 $this->prepareErrorPage( $title );
2779
2780                 if ( $msg instanceof Message ) {
2781                         if ( $params !== [] ) {
2782                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2783                                         . 'is discarded when the $msg argument is a Message object instead of '
2784                                         . 'a string.', E_USER_NOTICE );
2785                         }
2786                         $this->addHTML( $msg->parseAsBlock() );
2787                 } else {
2788                         $this->addWikiMsgArray( $msg, $params );
2789                 }
2790
2791                 $this->returnToMain();
2792         }
2793
2794         /**
2795          * Output a standard permission error page
2796          *
2797          * @param array $errors Error message keys or [key, param...] arrays
2798          * @param string|null $action Action that was denied or null if unknown
2799          */
2800         public function showPermissionsErrorPage( array $errors, $action = null ) {
2801                 foreach ( $errors as $key => $error ) {
2802                         $errors[$key] = (array)$error;
2803                 }
2804
2805                 // For some action (read, edit, create and upload), display a "login to do this action"
2806                 // error if all of the following conditions are met:
2807                 // 1. the user is not logged in
2808                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2809                 // 3. the error can be avoided simply by logging in
2810                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2811                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2812                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2813                         && ( User::groupHasPermission( 'user', $action )
2814                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2815                 ) {
2816                         $displayReturnto = null;
2817
2818                         # Due to T34276, if a user does not have read permissions,
2819                         # $this->getTitle() will just give Special:Badtitle, which is
2820                         # not especially useful as a returnto parameter. Use the title
2821                         # from the request instead, if there was one.
2822                         $request = $this->getRequest();
2823                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2824                         if ( $action == 'edit' ) {
2825                                 $msg = 'whitelistedittext';
2826                                 $displayReturnto = $returnto;
2827                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2828                                 $msg = 'nocreatetext';
2829                         } elseif ( $action == 'upload' ) {
2830                                 $msg = 'uploadnologintext';
2831                         } else { # Read
2832                                 $msg = 'loginreqpagetext';
2833                                 $displayReturnto = Title::newMainPage();
2834                         }
2835
2836                         $query = [];
2837
2838                         if ( $returnto ) {
2839                                 $query['returnto'] = $returnto->getPrefixedText();
2840
2841                                 if ( !$request->wasPosted() ) {
2842                                         $returntoquery = $request->getValues();
2843                                         unset( $returntoquery['title'] );
2844                                         unset( $returntoquery['returnto'] );
2845                                         unset( $returntoquery['returntoquery'] );
2846                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2847                                 }
2848                         }
2849                         $title = SpecialPage::getTitleFor( 'Userlogin' );
2850                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2851                         $loginUrl = $title->getLinkURL( $query, false, PROTO_RELATIVE );
2852                         $loginLink = $linkRenderer->makeKnownLink(
2853                                 $title,
2854                                 $this->msg( 'loginreqlink' )->text(),
2855                                 [],
2856                                 $query
2857                         );
2858
2859                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2860                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->params( $loginUrl )->parse() );
2861
2862                         # Don't return to a page the user can't read otherwise
2863                         # we'll end up in a pointless loop
2864                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2865                                 $this->returnToMain( null, $displayReturnto );
2866                         }
2867                 } else {
2868                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2869                         $this->addWikiTextAsInterface( $this->formatPermissionsErrorMessage( $errors, $action ) );
2870                 }
2871         }
2872
2873         /**
2874          * Display an error page indicating that a given version of MediaWiki is
2875          * required to use it
2876          *
2877          * @param mixed $version The version of MediaWiki needed to use the page
2878          */
2879         public function versionRequired( $version ) {
2880                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2881
2882                 $this->addWikiMsg( 'versionrequiredtext', $version );
2883                 $this->returnToMain();
2884         }
2885
2886         /**
2887          * Format a list of error messages
2888          *
2889          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2890          * @param string|null $action Action that was denied or null if unknown
2891          * @return string The wikitext error-messages, formatted into a list.
2892          */
2893         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2894                 if ( $action == null ) {
2895                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2896                 } else {
2897                         $action_desc = $this->msg( "action-$action" )->plain();
2898                         $text = $this->msg(
2899                                 'permissionserrorstext-withaction',
2900                                 count( $errors ),
2901                                 $action_desc
2902                         )->plain() . "\n\n";
2903                 }
2904
2905                 if ( count( $errors ) > 1 ) {
2906                         $text .= '<ul class="permissions-errors">' . "\n";
2907
2908                         foreach ( $errors as $error ) {
2909                                 $text .= '<li>';
2910                                 $text .= $this->msg( ...$error )->plain();
2911                                 $text .= "</li>\n";
2912                         }
2913                         $text .= '</ul>';
2914                 } else {
2915                         $text .= "<div class=\"permissions-errors\">\n" .
2916                                         $this->msg( ...reset( $errors ) )->plain() .
2917                                         "\n</div>";
2918                 }
2919
2920                 return $text;
2921         }
2922
2923         /**
2924          * Show a warning about replica DB lag
2925          *
2926          * If the lag is higher than $wgSlaveLagCritical seconds,
2927          * then the warning is a bit more obvious. If the lag is
2928          * lower than $wgSlaveLagWarning, then no warning is shown.
2929          *
2930          * @param int $lag Replica lag
2931          */
2932         public function showLagWarning( $lag ) {
2933                 $config = $this->getConfig();
2934                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2935                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2936                         $message = $lag < $config->get( 'SlaveLagCritical' )
2937                                 ? 'lag-warn-normal'
2938                                 : 'lag-warn-high';
2939                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2940                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2941                 }
2942         }
2943
2944         /**
2945          * Output an error page
2946          *
2947          * @note FatalError exception class provides an alternative.
2948          * @param string $message Error to output. Must be escaped for HTML.
2949          */
2950         public function showFatalError( $message ) {
2951                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2952
2953                 $this->addHTML( $message );
2954         }
2955
2956         /**
2957          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2958          */
2959         public function showUnexpectedValueError( $name, $val ) {
2960                 wfDeprecated( __METHOD__, '1.32' );
2961                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->escaped() );
2962         }
2963
2964         /**
2965          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2966          */
2967         public function showFileCopyError( $old, $new ) {
2968                 wfDeprecated( __METHOD__, '1.32' );
2969                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->escaped() );
2970         }
2971
2972         /**
2973          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2974          */
2975         public function showFileRenameError( $old, $new ) {
2976                 wfDeprecated( __METHOD__, '1.32' );
2977                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->escpaed() );
2978         }
2979
2980         /**
2981          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2982          */
2983         public function showFileDeleteError( $name ) {
2984                 wfDeprecated( __METHOD__, '1.32' );
2985                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->escaped() );
2986         }
2987
2988         /**
2989          * @deprecated 1.32 Use OutputPage::showFatalError or throw FatalError instead.
2990          */
2991         public function showFileNotFoundError( $name ) {
2992                 wfDeprecated( __METHOD__, '1.32' );
2993                 $this->showFatalError( $this->msg( 'filenotfound', $name )->escaped() );
2994         }
2995
2996         /**
2997          * Add a "return to" link pointing to a specified title
2998          *
2999          * @param Title $title Title to link
3000          * @param array $query Query string parameters
3001          * @param string|null $text Text of the link (input is not escaped)
3002          * @param array $options Options array to pass to Linker
3003          */
3004         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
3005                 $linkRenderer = MediaWikiServices::getInstance()
3006                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
3007                 $link = $this->msg( 'returnto' )->rawParams(
3008                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
3009                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
3010         }
3011
3012         /**
3013          * Add a "return to" link pointing to a specified title,
3014          * or the title indicated in the request, or else the main page
3015          *
3016          * @param mixed|null $unused
3017          * @param Title|string|null $returnto Title or String to return to
3018          * @param string|null $returntoquery Query string for the return to link
3019          */
3020         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
3021                 if ( $returnto == null ) {
3022                         $returnto = $this->getRequest()->getText( 'returnto' );
3023                 }
3024
3025                 if ( $returntoquery == null ) {
3026                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
3027                 }
3028
3029                 if ( $returnto === '' ) {
3030                         $returnto = Title::newMainPage();
3031                 }
3032
3033                 if ( is_object( $returnto ) ) {
3034                         $titleObj = $returnto;
3035                 } else {
3036                         $titleObj = Title::newFromText( $returnto );
3037                 }
3038                 // We don't want people to return to external interwiki. That
3039                 // might potentially be used as part of a phishing scheme
3040                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
3041                         $titleObj = Title::newMainPage();
3042                 }
3043
3044                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
3045         }
3046
3047         private function getRlClientContext() {
3048                 if ( !$this->rlClientContext ) {
3049                         $query = ResourceLoader::makeLoaderQuery(
3050                                 [], // modules; not relevant
3051                                 $this->getLanguage()->getCode(),
3052                                 $this->getSkin()->getSkinName(),
3053                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
3054                                 null, // version; not relevant
3055                                 ResourceLoader::inDebugMode(),
3056                                 null, // only; not relevant
3057                                 $this->isPrintable(),
3058                                 $this->getRequest()->getBool( 'handheld' )
3059                         );
3060                         $this->rlClientContext = new ResourceLoaderContext(
3061                                 $this->getResourceLoader(),
3062                                 new FauxRequest( $query )
3063                         );
3064                         if ( $this->contentOverrideCallbacks ) {
3065                                 $this->rlClientContext = new DerivativeResourceLoaderContext( $this->rlClientContext );
3066                                 $this->rlClientContext->setContentOverrideCallback( function ( Title $title ) {
3067                                         foreach ( $this->contentOverrideCallbacks as $callback ) {
3068                                                 $content = $callback( $title );
3069                                                 if ( $content !== null ) {
3070                                                         $text = ContentHandler::getContentText( $content );
3071                                                         if ( strpos( $text, '</script>' ) !== false ) {
3072                                                                 // Proactively replace this so that we can display a message
3073                                                                 // to the user, instead of letting it go to Html::inlineScript(),
3074                                                                 // where it would be considered a server-side issue.
3075                                                                 $titleFormatted = $title->getPrefixedText();
3076                                                                 $content = new JavaScriptContent(
3077                                                                         Xml::encodeJsCall( 'mw.log.error', [
3078                                                                                 "Cannot preview $titleFormatted due to script-closing tag."
3079                                                                         ] )
3080                                                                 );
3081                                                         }
3082                                                         return $content;
3083                                                 }
3084                                         }
3085                                         return null;
3086                                 } );
3087                         }
3088                 }
3089                 return $this->rlClientContext;
3090         }
3091
3092         /**
3093          * Call this to freeze the module queue and JS config and create a formatter.
3094          *
3095          * Depending on the Skin, this may get lazy-initialised in either headElement() or
3096          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
3097          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
3098          * the module filters retroactively. Skins and extension hooks may also add modules until very
3099          * late in the request lifecycle.
3100          *
3101          * @return ResourceLoaderClientHtml
3102          */
3103         public function getRlClient() {
3104                 if ( !$this->rlClient ) {
3105                         $context = $this->getRlClientContext();
3106                         $rl = $this->getResourceLoader();
3107                         $this->addModules( [
3108                                 'user',
3109                                 'user.options',
3110                                 'user.tokens',
3111                         ] );
3112                         $this->addModuleStyles( [
3113                                 'site.styles',
3114                                 'noscript',
3115                                 'user.styles',
3116                         ] );
3117                         $this->getSkin()->setupSkinUserCss( $this );
3118
3119                         // Prepare exempt modules for buildExemptModules()
3120                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
3121                         $exemptStates = [];
3122                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
3123
3124                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
3125                         // Separate user-specific batch for improved cache-hit ratio.
3126                         $userBatch = [ 'user.styles', 'user' ];
3127                         $siteBatch = array_diff( $moduleStyles, $userBatch );
3128                         $dbr = wfGetDB( DB_REPLICA );
3129                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
3130                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
3131
3132                         // Filter out modules handled by buildExemptModules()
3133                         $moduleStyles = array_filter( $moduleStyles,
3134                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
3135                                         $module = $rl->getModule( $name );
3136                                         if ( $module ) {
3137                                                 $group = $module->getGroup();
3138                                                 if ( isset( $exemptGroups[$group] ) ) {
3139                                                         $exemptStates[$name] = 'ready';
3140                                                         if ( !$module->isKnownEmpty( $context ) ) {
3141                                                                 // E.g. Don't output empty <styles>
3142                                                                 $exemptGroups[$group][] = $name;
3143                                                         }
3144                                                         return false;
3145                                                 }
3146                                         }
3147                                         return true;
3148                                 }
3149                         );
3150                         $this->rlExemptStyleModules = $exemptGroups;
3151
3152                         $rlClient = new ResourceLoaderClientHtml( $context, [
3153                                 'target' => $this->getTarget(),
3154                                 'nonce' => $this->getCSPNonce(),
3155                                 // When 'safemode', disallowUserJs(), or reduceAllowedModules() is used
3156                                 // to only restrict modules to ORIGIN_CORE (ie. disallow ORIGIN_USER), the list of
3157                                 // modules enqueud for loading on this page is filtered to just those.
3158                                 // However, to make sure we also apply the restriction to dynamic dependencies and
3159                                 // lazy-loaded modules at run-time on the client-side, pass 'safemode' down to the
3160                                 // StartupModule so that the client-side registry will not contain any restricted
3161                                 // modules either. (T152169, T185303)
3162                                 'safemode' => ( $this->getAllowedModules( ResourceLoaderModule::TYPE_COMBINED )
3163                                         <= ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
3164                                 ) ? '1' : null,
3165                         ] );
3166                         $rlClient->setConfig( $this->getJSVars() );
3167                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
3168                         $rlClient->setModuleStyles( $moduleStyles );
3169                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
3170                         $rlClient->setExemptStates( $exemptStates );
3171                         $this->rlClient = $rlClient;
3172                 }
3173                 return $this->rlClient;
3174         }
3175
3176         /**
3177          * @param Skin $sk The given Skin
3178          * @param bool $includeStyle Unused
3179          * @return string The doctype, opening "<html>", and head element.
3180          */
3181         public function headElement( Skin $sk, $includeStyle = true ) {
3182                 $userdir = $this->getLanguage()->getDir();
3183                 $sitedir = MediaWikiServices::getInstance()->getContentLanguage()->getDir();
3184
3185                 $pieces = [];
3186                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
3187                         $this->getRlClient()->getDocumentAttributes(),
3188                         $sk->getHtmlElementAttributes()
3189                 ) );
3190                 $pieces[] = Html::openElement( 'head' );
3191
3192                 if ( $this->getHTMLTitle() == '' ) {
3193                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
3194                 }
3195
3196                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
3197                         // Add <meta charset="UTF-8">
3198                         // This should be before <title> since it defines the charset used by
3199                         // text including the text inside <title>.
3200                         // The spec recommends defining XHTML5's charset using the XML declaration
3201                         // instead of meta.
3202                         // Our XML declaration is output by Html::htmlHeader.
3203                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
3204                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
3205                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
3206                 }
3207
3208                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
3209                 $pieces[] = $this->getRlClient()->getHeadHtml();
3210                 $pieces[] = $this->buildExemptModules();
3211                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
3212                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
3213
3214                 // Use an IE conditional comment to serve the script only to old IE
3215                 $pieces[] = '<!--[if lt IE 9]>' .
3216                         ResourceLoaderClientHtml::makeLoad(
3217                                 ResourceLoaderContext::newDummyContext(),
3218                                 [ 'html5shiv' ],
3219                                 ResourceLoaderModule::TYPE_SCRIPTS,
3220                                 [ 'sync' => true ],
3221                                 $this->getCSPNonce()
3222                         ) .
3223                         '<![endif]-->';
3224
3225                 $pieces[] = Html::closeElement( 'head' );
3226
3227                 $bodyClasses = $this->mAdditionalBodyClasses;
3228                 $bodyClasses[] = 'mediawiki';
3229
3230                 # Classes for LTR/RTL directionality support
3231                 $bodyClasses[] = $userdir;
3232                 $bodyClasses[] = "sitedir-$sitedir";
3233
3234                 $underline = $this->getUser()->getOption( 'underline' );
3235                 if ( $underline < 2 ) {
3236                         // The following classes can be used here:
3237                         // * mw-underline-always
3238                         // * mw-underline-never
3239                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
3240                 }
3241
3242                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
3243                         # A <body> class is probably not the best way to do this . . .
3244                         $bodyClasses[] = 'capitalize-all-nouns';
3245                 }
3246
3247                 // Parser feature migration class
3248                 // The idea is that this will eventually be removed, after the wikitext
3249                 // which requires it is cleaned up.
3250                 $bodyClasses[] = 'mw-hide-empty-elt';
3251
3252                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
3253                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
3254                 $bodyClasses[] =
3255                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
3256
3257                 $bodyAttrs = [];
3258                 // While the implode() is not strictly needed, it's used for backwards compatibility
3259                 // (this used to be built as a string and hooks likely still expect that).
3260                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
3261
3262                 // Allow skins and extensions to add body attributes they need
3263                 $sk->addToBodyAttributes( $this, $bodyAttrs );
3264                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
3265
3266                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
3267
3268                 return self::combineWrappedStrings( $pieces );
3269         }
3270
3271         /**
3272          * Get a ResourceLoader object associated with this OutputPage
3273          *
3274          * @return ResourceLoader
3275          */
3276         public function getResourceLoader() {
3277                 if ( is_null( $this->mResourceLoader ) ) {
3278                         // Lazy-initialise as needed
3279                         $this->mResourceLoader = MediaWikiServices::getInstance()->getResourceLoader();
3280                 }
3281                 return $this->mResourceLoader;
3282         }
3283
3284         /**
3285          * Explicily load or embed modules on a page.
3286          *
3287          * @param array|string $modules One or more module names
3288          * @param string $only ResourceLoaderModule TYPE_ class constant
3289          * @param array $extraQuery [optional] Array with extra query parameters for the request
3290          * @return string|WrappedStringList HTML
3291          */
3292         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
3293                 // Apply 'target' and 'origin' filters
3294                 $modules = $this->filterModules( (array)$modules, null, $only );
3295
3296                 return ResourceLoaderClientHtml::makeLoad(
3297                         $this->getRlClientContext(),
3298                         $modules,
3299                         $only,
3300                         $extraQuery,
3301                         $this->getCSPNonce()
3302                 );
3303         }
3304
3305         /**
3306          * Combine WrappedString chunks and filter out empty ones
3307          *
3308          * @param array $chunks
3309          * @return string|WrappedStringList HTML
3310          */
3311         protected static function combineWrappedStrings( array $chunks ) {
3312                 // Filter out empty values
3313                 $chunks = array_filter( $chunks, 'strlen' );
3314                 return WrappedString::join( "\n", $chunks );
3315         }
3316
3317         /**
3318          * JS stuff to put at the bottom of the `<body>`.
3319          * These are legacy scripts ($this->mScripts), and user JS.
3320          *
3321          * @return string|WrappedStringList HTML
3322          */
3323         public function getBottomScripts() {
3324                 $chunks = [];
3325                 $chunks[] = $this->getRlClient()->getBodyHtml();
3326
3327                 // Legacy non-ResourceLoader scripts
3328                 $chunks[] = $this->mScripts;
3329
3330                 if ( $this->limitReportJSData ) {
3331                         $chunks[] = ResourceLoader::makeInlineScript(
3332                                 ResourceLoader::makeConfigSetScript(
3333                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3334                                 ),
3335                                 $this->getCSPNonce()
3336                         );
3337                 }
3338
3339                 return self::combineWrappedStrings( $chunks );
3340         }
3341
3342         /**
3343          * Get the javascript config vars to include on this page
3344          *
3345          * @return array Array of javascript config vars
3346          * @since 1.23
3347          */
3348         public function getJsConfigVars() {
3349                 return $this->mJsConfigVars;
3350         }
3351
3352         /**
3353          * Add one or more variables to be set in mw.config in JavaScript
3354          *
3355          * @param string|array $keys Key or array of key/value pairs
3356          * @param mixed|null $value [optional] Value of the configuration variable
3357          */
3358         public function addJsConfigVars( $keys, $value = null ) {
3359                 if ( is_array( $keys ) ) {
3360                         foreach ( $keys as $key => $value ) {
3361                                 $this->mJsConfigVars[$key] = $value;
3362                         }
3363                         return;
3364                 }
3365
3366                 $this->mJsConfigVars[$keys] = $value;
3367         }
3368
3369         /**
3370          * Get an array containing the variables to be set in mw.config in JavaScript.
3371          *
3372          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3373          * - in other words, page-independent/site-wide variables (without state).
3374          * You will only be adding bloat to the html page and causing page caches to
3375          * have to be purged on configuration changes.
3376          * @return array
3377          */
3378         public function getJSVars() {
3379                 $curRevisionId = 0;
3380                 $articleId = 0;
3381                 $canonicalSpecialPageName = false; # T23115
3382                 $services = MediaWikiServices::getInstance();
3383
3384                 $title = $this->getTitle();
3385                 $ns = $title->getNamespace();
3386                 $canonicalNamespace = MWNamespace::exists( $ns )
3387                         ? MWNamespace::getCanonicalName( $ns )
3388                         : $title->getNsText();
3389
3390                 $sk = $this->getSkin();
3391                 // Get the relevant title so that AJAX features can use the correct page name
3392                 // when making API requests from certain special pages (T36972).
3393                 $relevantTitle = $sk->getRelevantTitle();
3394                 $relevantUser = $sk->getRelevantUser();
3395
3396                 if ( $ns == NS_SPECIAL ) {
3397                         list( $canonicalSpecialPageName, /*...*/ ) =
3398                                 $services->getSpecialPageFactory()->
3399                                         resolveAlias( $title->getDBkey() );
3400                 } elseif ( $this->canUseWikiPage() ) {
3401                         $wikiPage = $this->getWikiPage();
3402                         $curRevisionId = $wikiPage->getLatest();
3403                         $articleId = $wikiPage->getId();
3404                 }
3405
3406                 $lang = $title->getPageViewLanguage();
3407
3408                 // Pre-process information
3409                 $separatorTransTable = $lang->separatorTransformTable();
3410                 $separatorTransTable = $separatorTransTable ?: [];
3411                 $compactSeparatorTransTable = [
3412                         implode( "\t", array_keys( $separatorTransTable ) ),
3413                         implode( "\t", $separatorTransTable ),
3414                 ];
3415                 $digitTransTable = $lang->digitTransformTable();
3416                 $digitTransTable = $digitTransTable ?: [];
3417                 $compactDigitTransTable = [
3418                         implode( "\t", array_keys( $digitTransTable ) ),
3419                         implode( "\t", $digitTransTable ),
3420                 ];
3421
3422                 $user = $this->getUser();
3423
3424                 $vars = [
3425                         'wgCanonicalNamespace' => $canonicalNamespace,
3426                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3427                         'wgNamespaceNumber' => $title->getNamespace(),
3428                         'wgPageName' => $title->getPrefixedDBkey(),
3429                         'wgTitle' => $title->getText(),
3430                         'wgCurRevisionId' => $curRevisionId,
3431                         'wgRevisionId' => (int)$this->getRevisionId(),
3432                         'wgArticleId' => $articleId,
3433                         'wgIsArticle' => $this->isArticle(),
3434                         'wgIsRedirect' => $title->isRedirect(),
3435                         'wgAction' => Action::getActionName( $this->getContext() ),
3436                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3437                         'wgUserGroups' => $user->getEffectiveGroups(),
3438                         'wgCategories' => $this->getCategories(),
3439                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3440                         'wgPageContentLanguage' => $lang->getCode(),
3441                         'wgPageContentModel' => $title->getContentModel(),
3442                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3443                         'wgDigitTransformTable' => $compactDigitTransTable,
3444                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3445                         'wgMonthNames' => $lang->getMonthNamesArray(),
3446                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3447                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3448                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3449                         'wgRequestId' => WebRequest::getRequestId(),
3450                         'wgCSPNonce' => $this->getCSPNonce(),
3451                 ];
3452
3453                 if ( $user->isLoggedIn() ) {
3454                         $vars['wgUserId'] = $user->getId();
3455                         $vars['wgUserEditCount'] = $user->getEditCount();
3456                         $userReg = $user->getRegistration();
3457                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3458                         // Get the revision ID of the oldest new message on the user's talk
3459                         // page. This can be used for constructing new message alerts on
3460                         // the client side.
3461                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3462                 }
3463
3464                 $contLang = $services->getContentLanguage();
3465                 if ( $contLang->hasVariants() ) {
3466                         $vars['wgUserVariant'] = $contLang->getPreferredVariant();
3467                 }
3468                 // Same test as SkinTemplate
3469                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3470                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3471
3472                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3473                         && $relevantTitle->quickUserCan( 'edit', $user )
3474                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3475
3476                 foreach ( $title->getRestrictionTypes() as $type ) {
3477                         // Following keys are set in $vars:
3478                         // wgRestrictionCreate, wgRestrictionEdit, wgRestrictionMove, wgRestrictionUpload
3479                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3480                 }
3481
3482                 if ( $title->isMainPage() ) {
3483                         $vars['wgIsMainPage'] = true;
3484                 }
3485
3486                 if ( $this->mRedirectedFrom ) {
3487                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3488                 }
3489
3490                 if ( $relevantUser ) {
3491                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3492                 }
3493
3494                 // Allow extensions to add their custom variables to the mw.config map.
3495                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3496                 // page-dependant but site-wide (without state).
3497                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3498                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3499
3500                 // Merge in variables from addJsConfigVars last
3501                 return array_merge( $vars, $this->getJsConfigVars() );
3502         }
3503
3504         /**
3505          * To make it harder for someone to slip a user a fake
3506          * JavaScript or CSS preview, a random token
3507          * is associated with the login session. If it's not
3508          * passed back with the preview request, we won't render
3509          * the code.
3510          *
3511          * @return bool
3512          */
3513         public function userCanPreview() {
3514                 $request = $this->getRequest();
3515                 if (
3516                         $request->getVal( 'action' ) !== 'submit' ||
3517                         !$request->wasPosted()
3518                 ) {
3519                         return false;
3520                 }
3521
3522                 $user = $this->getUser();
3523
3524                 if ( !$user->isLoggedIn() ) {
3525                         // Anons have predictable edit tokens
3526                         return false;
3527                 }
3528                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3529                         return false;
3530                 }
3531
3532                 $title = $this->getTitle();
3533                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3534                 if ( count( $errors ) !== 0 ) {
3535                         return false;
3536                 }
3537
3538                 return true;
3539         }
3540
3541         /**
3542          * @return array Array in format "link name or number => 'link html'".
3543          */
3544         public function getHeadLinksArray() {
3545                 global $wgVersion;
3546
3547                 $tags = [];
3548                 $config = $this->getConfig();
3549
3550                 $canonicalUrl = $this->mCanonicalUrl;
3551
3552                 $tags['meta-generator'] = Html::element( 'meta', [
3553                         'name' => 'generator',
3554                         'content' => "MediaWiki $wgVersion",
3555                 ] );
3556
3557                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3558                         // Per https://w3c.github.io/webappsec-referrer-policy/#unknown-policy-values
3559                         // fallbacks should come before the primary value so we need to reverse the array.
3560                         foreach ( array_reverse( (array)$config->get( 'ReferrerPolicy' ) ) as $i => $policy ) {
3561                                 $tags["meta-referrer-$i"] = Html::element( 'meta', [
3562                                         'name' => 'referrer',
3563                                         'content' => $policy,
3564                                 ] );
3565                         }
3566                 }
3567
3568                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3569                 if ( $p !== 'index,follow' ) {
3570                         // http://www.robotstxt.org/wc/meta-user.html
3571                         // Only show if it's different from the default robots policy
3572                         $tags['meta-robots'] = Html::element( 'meta', [
3573                                 'name' => 'robots',
3574                                 'content' => $p,
3575                         ] );
3576                 }
3577
3578                 foreach ( $this->mMetatags as $tag ) {
3579                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3580                                 $a = 'http-equiv';
3581                                 $tag[0] = substr( $tag[0], 5 );
3582                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3583                                 $a = 'property';
3584                         } else {
3585                                 $a = 'name';
3586                         }
3587                         $tagName = "meta-{$tag[0]}";
3588                         if ( isset( $tags[$tagName] ) ) {
3589                                 $tagName .= $tag[1];
3590                         }
3591                         $tags[$tagName] = Html::element( 'meta',
3592                                 [
3593                                         $a => $tag[0],
3594                                         'content' => $tag[1]
3595                                 ]
3596                         );
3597                 }
3598
3599                 foreach ( $this->mLinktags as $tag ) {
3600                         $tags[] = Html::element( 'link', $tag );
3601                 }
3602
3603                 # Universal edit button
3604                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3605                         $user = $this->getUser();
3606                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3607                                 && ( $this->getTitle()->exists() ||
3608                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3609                         ) {
3610                                 // Original UniversalEditButton
3611                                 $msg = $this->msg( 'edit' )->text();
3612                                 $tags['universal-edit-button'] = Html::element( 'link', [
3613                                         'rel' => 'alternate',
3614                                         'type' => 'application/x-wiki',
3615                                         'title' => $msg,
3616                                         'href' => $this->getTitle()->getEditURL(),
3617                                 ] );
3618                                 // Alternate edit link
3619                                 $tags['alternative-edit'] = Html::element( 'link', [
3620                                         'rel' => 'edit',
3621                                         'title' => $msg,
3622                                         'href' => $this->getTitle()->getEditURL(),
3623                                 ] );
3624                         }
3625                 }
3626
3627                 # Generally the order of the favicon and apple-touch-icon links
3628                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3629                 # uses whichever one appears later in the HTML source. Make sure
3630                 # apple-touch-icon is specified first to avoid this.
3631                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3632                         $tags['apple-touch-icon'] = Html::element( 'link', [
3633                                 'rel' => 'apple-touch-icon',
3634                                 'href' => $config->get( 'AppleTouchIcon' )
3635                         ] );
3636                 }
3637
3638                 if ( $config->get( 'Favicon' ) !== false ) {
3639                         $tags['favicon'] = Html::element( 'link', [
3640                                 'rel' => 'shortcut icon',
3641                                 'href' => $config->get( 'Favicon' )
3642                         ] );
3643                 }
3644
3645                 # OpenSearch description link
3646                 $tags['opensearch'] = Html::element( 'link', [
3647                         'rel' => 'search',
3648                         'type' => 'application/opensearchdescription+xml',
3649                         'href' => wfScript( 'opensearch_desc' ),
3650                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3651                 ] );
3652
3653                 # Real Simple Discovery link, provides auto-discovery information
3654                 # for the MediaWiki API (and potentially additional custom API
3655                 # support such as WordPress or Twitter-compatible APIs for a
3656                 # blogging extension, etc)
3657                 $tags['rsd'] = Html::element( 'link', [
3658                         'rel' => 'EditURI',
3659                         'type' => 'application/rsd+xml',
3660                         // Output a protocol-relative URL here if $wgServer is protocol-relative.
3661                         // Whether RSD accepts relative or protocol-relative URLs is completely
3662                         // undocumented, though.
3663                         'href' => wfExpandUrl( wfAppendQuery(
3664                                 wfScript( 'api' ),
3665                                 [ 'action' => 'rsd' ] ),
3666                                 PROTO_RELATIVE
3667                         ),
3668                 ] );
3669
3670                 # Language variants
3671                 if ( !$config->get( 'DisableLangConversion' ) ) {
3672                         $lang = $this->getTitle()->getPageLanguage();
3673                         if ( $lang->hasVariants() ) {
3674                                 $variants = $lang->getVariants();
3675                                 foreach ( $variants as $variant ) {
3676                                         $tags["variant-$variant"] = Html::element( 'link', [
3677                                                 'rel' => 'alternate',
3678                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3679                                                 'href' => $this->getTitle()->getLocalURL(
3680                                                         [ 'variant' => $variant ] )
3681                                                 ]
3682                                         );
3683                                 }
3684                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3685                                 $tags["variant-x-default"] = Html::element( 'link', [
3686                                         'rel' => 'alternate',
3687                                         'hreflang' => 'x-default',
3688                                         'href' => $this->getTitle()->getLocalURL() ] );
3689                         }
3690                 }
3691
3692                 # Copyright
3693                 if ( $this->copyrightUrl !== null ) {
3694                         $copyright = $this->copyrightUrl;
3695                 } else {
3696                         $copyright = '';
3697                         if ( $config->get( 'RightsPage' ) ) {
3698                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3699
3700                                 if ( $copy ) {
3701                                         $copyright = $copy->getLocalURL();
3702                                 }
3703                         }
3704
3705                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3706                                 $copyright = $config->get( 'RightsUrl' );
3707                         }
3708                 }
3709
3710                 if ( $copyright ) {
3711                         $tags['copyright'] = Html::element( 'link', [
3712                                 'rel' => 'license',
3713                                 'href' => $copyright ]
3714                         );
3715                 }
3716
3717                 # Feeds
3718                 if ( $config->get( 'Feed' ) ) {
3719                         $feedLinks = [];
3720
3721                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3722                                 # Use the page name for the title.  In principle, this could
3723                                 # lead to issues with having the same name for different feeds
3724                                 # corresponding to the same page, but we can't avoid that at
3725                                 # this low a level.
3726
3727                                 $feedLinks[] = $this->feedLink(
3728                                         $format,
3729                                         $link,
3730                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3731                                         $this->msg(
3732                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3733                                         )->text()
3734                                 );
3735                         }
3736
3737                         # Recent changes feed should appear on every page (except recentchanges,
3738                         # that would be redundant). Put it after the per-page feed to avoid
3739                         # changing existing behavior. It's still available, probably via a
3740                         # menu in your browser. Some sites might have a different feed they'd
3741                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3742                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3743                         # If so, use it instead.
3744                         $sitename = $config->get( 'Sitename' );
3745                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3746                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3747                                         // Note, this->feedLink escapes the url.
3748                                         $feedLinks[] = $this->feedLink(
3749                                                 $type,
3750                                                 $feedUrl,
3751                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3752                                         );
3753                                 }
3754                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3755                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3756                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3757                                         $feedLinks[] = $this->feedLink(
3758                                                 $format,
3759                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3760                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3761                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3762                                         );
3763                                 }
3764                         }
3765
3766                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3767                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3768                         # use OutputPage::addFeedLink() instead.
3769                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3770
3771                         $tags += $feedLinks;
3772                 }
3773
3774                 # Canonical URL
3775                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3776                         if ( $canonicalUrl !== false ) {
3777                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3778                         } else {
3779                                 if ( $this->isArticleRelated() ) {
3780                                         // This affects all requests where "setArticleRelated" is true. This is
3781                                         // typically all requests that show content (query title, curid, oldid, diff),
3782                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3783                                         // It does not apply to File pages and Special pages.
3784                                         // 'history' and 'info' actions address page metadata rather than the page
3785                                         // content itself, so they may not be canonicalized to the view page url.
3786                                         // TODO: this ought to be better encapsulated in the Action class.
3787                                         $action = Action::getActionName( $this->getContext() );
3788                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3789                                                 $query = "action={$action}";
3790                                         } else {
3791                                                 $query = '';
3792                                         }
3793                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3794                                 } else {
3795                                         $reqUrl = $this->getRequest()->getRequestURL();
3796                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3797                                 }
3798                         }
3799                 }
3800                 if ( $canonicalUrl !== false ) {
3801                         $tags[] = Html::element( 'link', [
3802                                 'rel' => 'canonical',
3803                                 'href' => $canonicalUrl
3804                         ] );
3805                 }
3806
3807                 // Allow extensions to add, remove and/or otherwise manipulate these links
3808                 // If you want only to *add* <head> links, please use the addHeadItem()
3809                 // (or addHeadItems() for multiple items) method instead.
3810                 // This hook is provided as a last resort for extensions to modify these
3811                 // links before the output is sent to client.
3812                 Hooks::run( 'OutputPageAfterGetHeadLinksArray', [ &$tags, $this ] );
3813
3814                 return $tags;
3815         }
3816
3817         /**
3818          * Generate a "<link rel/>" for a feed.
3819          *
3820          * @param string $type Feed type
3821          * @param string $url URL to the feed
3822          * @param string $text Value of the "title" attribute
3823          * @return string HTML fragment
3824          */
3825         private function feedLink( $type, $url, $text ) {
3826                 return Html::element( 'link', [
3827                         'rel' => 'alternate',
3828                         'type' => "application/$type+xml",
3829                         'title' => $text,
3830                         'href' => $url ]
3831                 );
3832         }
3833
3834         /**
3835          * Add a local or specified stylesheet, with the given media options.
3836          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3837          *
3838          * @param string $style URL to the file
3839          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3840          * @param string $condition For IE conditional comments, specifying an IE version
3841          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3842          */
3843         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3844                 $options = [];
3845                 if ( $media ) {
3846                         $options['media'] = $media;
3847                 }
3848                 if ( $condition ) {
3849                         $options['condition'] = $condition;
3850                 }
3851                 if ( $dir ) {
3852                         $options['dir'] = $dir;
3853                 }
3854                 $this->styles[$style] = $options;
3855         }
3856
3857         /**
3858          * Adds inline CSS styles
3859          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3860          *
3861          * @param mixed $style_css Inline CSS
3862          * @param string $flip Set to 'flip' to flip the CSS if needed
3863          */
3864         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3865                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3866                         # If wanted, and the interface is right-to-left, flip the CSS
3867                         $style_css = CSSJanus::transform( $style_css, true, false );
3868                 }
3869                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3870         }
3871
3872         /**
3873          * Build exempt modules and legacy non-ResourceLoader styles.
3874          *
3875          * @return string|WrappedStringList HTML
3876          */
3877         protected function buildExemptModules() {
3878                 $chunks = [];
3879                 // Things that go after the ResourceLoaderDynamicStyles marker
3880                 $append = [];
3881
3882                 // We want site, private and user styles to override dynamically added styles from
3883                 // general modules, but we want dynamically added styles to override statically added
3884                 // style modules. So the order has to be:
3885                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3886                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3887                 // - ResourceLoaderDynamicStyles marker
3888                 // - site/private/user styles
3889
3890                 // Add legacy styles added through addStyle()/addInlineStyle() here
3891                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3892
3893                 $chunks[] = Html::element(
3894                         'meta',
3895                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3896                 );
3897
3898                 $separateReq = [ 'site.styles', 'user.styles' ];
3899                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3900                         // Combinable modules
3901                         $chunks[] = $this->makeResourceLoaderLink(
3902                                 array_diff( $moduleNames, $separateReq ),
3903                                 ResourceLoaderModule::TYPE_STYLES
3904                         );
3905
3906                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3907                                 // These require their own dedicated request in order to support "@import"
3908                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3909                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3910                                         ResourceLoaderModule::TYPE_STYLES
3911                                 );
3912                         }
3913                 }
3914
3915                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3916         }
3917
3918         /**
3919          * @return array
3920          */
3921         public function buildCssLinksArray() {
3922                 $links = [];
3923
3924                 foreach ( $this->styles as $file => $options ) {
3925                         $link = $this->styleLink( $file, $options );
3926                         if ( $link ) {
3927                                 $links[$file] = $link;
3928                         }
3929                 }
3930                 return $links;
3931         }
3932
3933         /**
3934          * Generate \<link\> tags for stylesheets
3935          *
3936          * @param string $style URL to the file
3937          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3938          * @return string HTML fragment
3939          */
3940         protected function styleLink( $style, array $options ) {
3941                 if ( isset( $options['dir'] ) ) {
3942                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3943                                 return '';
3944                         }
3945                 }
3946
3947                 if ( isset( $options['media'] ) ) {
3948                         $media = self::transformCssMedia( $options['media'] );
3949                         if ( is_null( $media ) ) {
3950                                 return '';
3951                         }
3952                 } else {
3953                         $media = 'all';
3954                 }
3955
3956                 if ( substr( $style, 0, 1 ) == '/' ||
3957                         substr( $style, 0, 5 ) == 'http:' ||
3958                         substr( $style, 0, 6 ) == 'https:' ) {
3959                         $url = $style;
3960                 } else {
3961                         $config = $this->getConfig();
3962                         // Append file hash as query parameter
3963                         $url = self::transformResourcePath(
3964                                 $config,
3965                                 $config->get( 'StylePath' ) . '/' . $style
3966                         );
3967                 }
3968
3969                 $link = Html::linkedStyle( $url, $media );
3970
3971                 if ( isset( $options['condition'] ) ) {
3972                         $condition = htmlspecialchars( $options['condition'] );
3973                         $link = "<!--[if $condition]>$link<![endif]-->";
3974                 }
3975                 return $link;
3976         }
3977
3978         /**
3979          * Transform path to web-accessible static resource.
3980          *
3981          * This is used to add a validation hash as query string.
3982          * This aids various behaviors:
3983          *
3984          * - Put long Cache-Control max-age headers on responses for improved
3985          *   cache performance.
3986          * - Get the correct version of a file as expected by the current page.
3987          * - Instantly get the updated version of a file after deployment.
3988          *
3989          * Avoid using this for urls included in HTML as otherwise clients may get different
3990          * versions of a resource when navigating the site depending on when the page was cached.
3991          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3992          * an external stylesheet).
3993          *
3994          * @since 1.27
3995          * @param Config $config
3996          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3997          * @return string URL
3998          */
3999         public static function transformResourcePath( Config $config, $path ) {
4000                 global $IP;
4001
4002                 $localDir = $IP;
4003                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
4004                 if ( $remotePathPrefix === '' ) {
4005                         // The configured base path is required to be empty string for
4006                         // wikis in the domain root
4007                         $remotePath = '/';
4008                 } else {
4009                         $remotePath = $remotePathPrefix;
4010                 }
4011                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
4012                         // - Path is outside wgResourceBasePath, ignore.
4013                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
4014                         return $path;
4015                 }
4016                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
4017                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
4018                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
4019                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
4020                 $uploadPath = $config->get( 'UploadPath' );
4021                 if ( strpos( $path, $uploadPath ) === 0 ) {
4022                         $localDir = $config->get( 'UploadDirectory' );
4023                         $remotePathPrefix = $remotePath = $uploadPath;
4024                 }
4025
4026                 $path = RelPath::getRelativePath( $path, $remotePath );
4027                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
4028         }
4029
4030         /**
4031          * Utility method for transformResourceFilePath().
4032          *
4033          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
4034          *
4035          * @since 1.27
4036          * @param string $remotePathPrefix URL path prefix that points to $localPath
4037          * @param string $localPath File directory exposed at $remotePath
4038          * @param string $file Path to target file relative to $localPath
4039          * @return string URL
4040          */
4041         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
4042                 $hash = md5_file( "$localPath/$file" );
4043                 if ( $hash === false ) {
4044                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
4045                         $hash = '';
4046                 }
4047                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
4048         }
4049
4050         /**
4051          * Transform "media" attribute based on request parameters
4052          *
4053          * @param string $media Current value of the "media" attribute
4054          * @return string Modified value of the "media" attribute, or null to skip
4055          * this stylesheet
4056          */
4057         public static function transformCssMedia( $media ) {
4058                 global $wgRequest;
4059
4060                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
4061                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
4062
4063                 // Switch in on-screen display for media testing
4064                 $switches = [
4065                         'printable' => 'print',
4066                         'handheld' => 'handheld',
4067                 ];
4068                 foreach ( $switches as $switch => $targetMedia ) {
4069                         if ( $wgRequest->getBool( $switch ) ) {
4070                                 if ( $media == $targetMedia ) {
4071                                         $media = '';
4072                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
4073                                         /* This regex will not attempt to understand a comma-separated media_query_list
4074                                          *
4075                                          * Example supported values for $media:
4076                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
4077                                          * Example NOT supported value for $media:
4078                                          * '3d-glasses, screen, print and resolution > 90dpi'
4079                                          *
4080                                          * If it's a print request, we never want any kind of screen stylesheets
4081                                          * If it's a handheld request (currently the only other choice with a switch),
4082                                          * we don't want simple 'screen' but we might want screen queries that
4083                                          * have a max-width or something, so we'll pass all others on and let the
4084                                          * client do the query.
4085                                          */
4086                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
4087                                                 return null;
4088                                         }
4089                                 }
4090                         }
4091                 }
4092
4093                 return $media;
4094         }
4095
4096         /**
4097          * Add a wikitext-formatted message to the output.
4098          * This is equivalent to:
4099          *
4100          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
4101          */
4102         public function addWikiMsg( /*...*/ ) {
4103                 $args = func_get_args();
4104                 $name = array_shift( $args );
4105                 $this->addWikiMsgArray( $name, $args );
4106         }
4107
4108         /**
4109          * Add a wikitext-formatted message to the output.
4110          * Like addWikiMsg() except the parameters are taken as an array
4111          * instead of a variable argument list.
4112          *
4113          * @param string $name
4114          * @param array $args
4115          */
4116         public function addWikiMsgArray( $name, $args ) {
4117                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
4118         }
4119
4120         /**
4121          * This function takes a number of message/argument specifications, wraps them in
4122          * some overall structure, and then parses the result and adds it to the output.
4123          *
4124          * In the $wrap, $1 is replaced with the first message, $2 with the second,
4125          * and so on. The subsequent arguments may be either
4126          * 1) strings, in which case they are message names, or
4127          * 2) arrays, in which case, within each array, the first element is the message
4128          *    name, and subsequent elements are the parameters to that message.
4129          *
4130          * Don't use this for messages that are not in the user's interface language.
4131          *
4132          * For example:
4133          *
4134          *     $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
4135          *
4136          * Is equivalent to:
4137          *
4138          *     $wgOut->addWikiTextAsInterface( "<div class='error'>\n"
4139          *         . wfMessage( 'some-error' )->plain() . "\n</div>" );
4140          *
4141          * The newline after the opening div is needed in some wikitext. See T21226.
4142          *
4143          * @param string $wrap
4144          */
4145         public function wrapWikiMsg( $wrap /*, ...*/ ) {
4146                 $msgSpecs = func_get_args();
4147                 array_shift( $msgSpecs );
4148                 $msgSpecs = array_values( $msgSpecs );
4149                 $s = $wrap;
4150                 foreach ( $msgSpecs as $n => $spec ) {
4151                         if ( is_array( $spec ) ) {
4152                                 $args = $spec;
4153                                 $name = array_shift( $args );
4154                                 if ( isset( $args['options'] ) ) {
4155                                         unset( $args['options'] );
4156                                         wfDeprecated(
4157                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
4158                                                 '1.20'
4159                                         );
4160                                 }
4161                         } else {
4162                                 $args = [];
4163                                 $name = $spec;
4164                         }
4165                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
4166                 }
4167                 $this->addWikiTextAsInterface( $s );
4168         }
4169
4170         /**
4171          * Whether the output has a table of contents
4172          * @return bool
4173          * @since 1.22
4174          */
4175         public function isTOCEnabled() {
4176                 return $this->mEnableTOC;
4177         }
4178
4179         /**
4180          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
4181          * @param bool $flag
4182          * @since 1.23
4183          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
4184          */
4185         public function enableSectionEditLinks( $flag = true ) {
4186                 wfDeprecated( __METHOD__, '1.31' );
4187         }
4188
4189         /**
4190          * @return bool
4191          * @since 1.23
4192          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
4193          */
4194         public function sectionEditLinksEnabled() {
4195                 wfDeprecated( __METHOD__, '1.31' );
4196                 return true;
4197         }
4198
4199         /**
4200          * Helper function to setup the PHP implementation of OOUI to use in this request.
4201          *
4202          * @since 1.26
4203          * @param string $skinName The Skin name to determine the correct OOUI theme
4204          * @param string $dir Language direction
4205          */
4206         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
4207                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
4208                 $theme = $themes[$skinName] ?? $themes['default'];
4209                 // For example, 'OOUI\WikimediaUITheme'.
4210                 $themeClass = "OOUI\\{$theme}Theme";
4211                 OOUI\Theme::setSingleton( new $themeClass() );
4212                 OOUI\Element::setDefaultDir( $dir );
4213         }
4214
4215         /**
4216          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
4217          * MediaWiki and this OutputPage instance.
4218          *
4219          * @since 1.25
4220          */
4221         public function enableOOUI() {
4222                 self::setupOOUI(
4223                         strtolower( $this->getSkin()->getSkinName() ),
4224                         $this->getLanguage()->getDir()
4225                 );
4226                 $this->addModuleStyles( [
4227                         'oojs-ui-core.styles',
4228                         'oojs-ui.styles.indicators',
4229                         'oojs-ui.styles.textures',
4230                         'mediawiki.widgets.styles',
4231                         'oojs-ui.styles.icons-content',
4232                         'oojs-ui.styles.icons-alerts',
4233                         'oojs-ui.styles.icons-interactions',
4234                 ] );
4235         }
4236
4237         /**
4238          * Get (and set if not yet set) the CSP nonce.
4239          *
4240          * This value needs to be included in any <script> tags on the
4241          * page.
4242          *
4243          * @return string|bool Nonce or false to mean don't output nonce
4244          * @since 1.32
4245          */
4246         public function getCSPNonce() {
4247                 if ( !ContentSecurityPolicy::isNonceRequired( $this->getConfig() ) ) {
4248                         return false;
4249                 }
4250                 if ( $this->CSPNonce === null ) {
4251                         // XXX It might be expensive to generate randomness
4252                         // on every request, on Windows.
4253                         $rand = random_bytes( 15 );
4254                         $this->CSPNonce = base64_encode( $rand );
4255                 }
4256                 return $this->CSPNonce;
4257         }
4258
4259 }