includes/OutputPage.php

   1 <?php
   2 /**
   3  * Preparation for the final page rendering.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use MediaWiki\Logger\LoggerFactory;
  24 use MediaWiki\Session\SessionManager;
  25 use WrappedString\WrappedString;
  26 use WrappedString\WrappedStringList;
  27
  28 /**
  29  * This class should be covered by a general architecture document which does
  30  * not exist as of January 2011.  This is one of the Core classes and should
  31  * be read at least once by any new developers.
  32  *
  33  * This class is used to prepare the final rendering. A skin is then
  34  * applied to the output parameters (links, javascript, html, categories ...).
  35  *
  36  * @todo FIXME: Another class handles sending the whole page to the client.
  37  *
  38  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  39  * in November 2010.
  40  *
  41  * @todo document
  42  */
  43 class OutputPage extends ContextSource {
  44         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  45         protected $mMetatags = [];
  46
  47         /** @var array */
  48         protected $mLinktags = [];
  49
  50         /** @var bool */
  51         protected $mCanonicalUrl = false;
  52
  53         /**
  54          * @var array Additional stylesheets. Looks like this is for extensions.
  55          *   Might be replaced by ResourceLoader.
  56          */
  57         protected $mExtStyles = [];
  58
  59         /**
  60          * @var string Should be private - has getter and setter. Contains
  61          *   the HTML title */
  62         public $mPagetitle = '';
  63
  64         /**
  65          * @var string Contains all of the "<body>" content. Should be private we
  66          *   got set/get accessors and the append() method.
  67          */
  68         public $mBodytext = '';
  69
  70         /**
  71          * Holds the debug lines that will be output as comments in page source if
  72          * $wgDebugComments is enabled. See also $wgShowDebug.
  73          * @deprecated since 1.20; use MWDebug class instead.
  74          */
  75         public $mDebugtext = '';
  76
  77         /** @var string Stores contents of "<title>" tag */
  78         private $mHTMLtitle = '';
  79
  80         /**
  81          * @var bool Is the displayed content related to the source of the
  82          *   corresponding wiki article.
  83          */
  84         private $mIsarticle = false;
  85
  86         /** @var bool Stores "article flag" toggle. */
  87         private $mIsArticleRelated = true;
  88
  89         /**
  90          * @var bool We have to set isPrintable(). Some pages should
  91          * never be printed (ex: redirections).
  92          */
  93         private $mPrintable = false;
  94
  95         /**
  96          * @var array Contains the page subtitle. Special pages usually have some
  97          *   links here. Don't confuse with site subtitle added by skins.
  98          */
  99         private $mSubtitle = [];
 100
 101         /** @var string */
 102         public $mRedirect = '';
 103
 104         /** @var int */
 105         protected $mStatusCode;
 106
 107         /**
 108          * @var string Used for sending cache control.
 109          *   The whole caching system should probably be moved into its own class.
 110          */
 111         protected $mLastModified = '';
 112
 113         /** @var array */
 114         protected $mCategoryLinks = [];
 115
 116         /** @var array */
 117         protected $mCategories = [];
 118
 119         /** @var array */
 120         protected $mIndicators = [];
 121
 122         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 123         private $mLanguageLinks = [];
 124
 125         /**
 126          * Used for JavaScript (predates ResourceLoader)
 127          * @todo We should split JS / CSS.
 128          * mScripts content is inserted as is in "<head>" by Skin. This might
 129          * contain either a link to a stylesheet or inline CSS.
 130          */
 131         private $mScripts = '';
 132
 133         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 134         protected $mInlineStyles = '';
 135
 136         /**
 137          * @var string Used by skin template.
 138          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 139          */
 140         public $mPageLinkTitle = '';
 141
 142         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 143         protected $mHeadItems = [];
 144
 145         /** @var array */
 146         protected $mModules = [];
 147
 148         /** @var array */
 149         protected $mModuleScripts = [];
 150
 151         /** @var array */
 152         protected $mModuleStyles = [];
 153
 154         /** @var ResourceLoader */
 155         protected $mResourceLoader;
 156
 157         /** @var ResourceLoaderClientHtml */
 158         private $rlClient;
 159
 160         /** @var ResourceLoaderContext */
 161         private $rlClientContext;
 162
 163         /** @var string */
 164         private $rlUserModuleState;
 165
 166         /** @var array */
 167         protected $mJsConfigVars = [];
 168
 169         /** @var array */
 170         protected $mTemplateIds = [];
 171
 172         /** @var array */
 173         protected $mImageTimeKeys = [];
 174
 175         /** @var string */
 176         public $mRedirectCode = '';
 177
 178         protected $mFeedLinksAppendQuery = null;
 179
 180         /** @var array
 181          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 182          * @see ResourceLoaderModule::$origin
 183          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 184          */
 185         protected $mAllowedModules = [
 186                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 187         ];
 188
 189         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 190         protected $mDoNothing = false;
 191
 192         // Parser related.
 193
 194         /** @var int */
 195         protected $mContainsNewMagic = 0;
 196
 197         /**
 198          * lazy initialised, use parserOptions()
 199          * @var ParserOptions
 200          */
 201         protected $mParserOptions = null;
 202
 203         /**
 204          * Handles the Atom / RSS links.
 205          * We probably only support Atom in 2011.
 206          * @see $wgAdvertisedFeedTypes
 207          */
 208         private $mFeedLinks = [];
 209
 210         // Gwicke work on squid caching? Roughly from 2003.
 211         protected $mEnableClientCache = true;
 212
 213         /** @var bool Flag if output should only contain the body of the article. */
 214         private $mArticleBodyOnly = false;
 215
 216         /** @var bool */
 217         protected $mNewSectionLink = false;
 218
 219         /** @var bool */
 220         protected $mHideNewSectionLink = false;
 221
 222         /**
 223          * @var bool Comes from the parser. This was probably made to load CSS/JS
 224          * only if we had "<gallery>". Used directly in CategoryPage.php.
 225          * Looks like ResourceLoader can replace this.
 226          */
 227         public $mNoGallery = false;
 228
 229         /** @var string */
 230         private $mPageTitleActionText = '';
 231
 232         /** @var int Cache stuff. Looks like mEnableClientCache */
 233         protected $mCdnMaxage = 0;
 234         /** @var int Upper limit on mCdnMaxage */
 235         protected $mCdnMaxageLimit = INF;
 236
 237         /**
 238          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 239          * be sent. This should be done for pages where edit actions are possible.
 240          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 241          */
 242         protected $mPreventClickjacking = true;
 243
 244         /** @var int To include the variable {{REVISIONID}} */
 245         private $mRevisionId = null;
 246
 247         /** @var string */
 248         private $mRevisionTimestamp = null;
 249
 250         /** @var array */
 251         protected $mFileVersion = null;
 252
 253         /**
 254          * @var array An array of stylesheet filenames (relative from skins path),
 255          * with options for CSS media, IE conditions, and RTL/LTR direction.
 256          * For internal use; add settings in the skin via $this->addStyle()
 257          *
 258          * Style again! This seems like a code duplication since we already have
 259          * mStyles. This is what makes Open Source amazing.
 260          */
 261         protected $styles = [];
 262
 263         private $mIndexPolicy = 'index';
 264         private $mFollowPolicy = 'follow';
 265         private $mVaryHeader = [
 266                 'Accept-Encoding' => [ 'match=gzip' ],
 267         ];
 268
 269         /**
 270          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 271          * of the redirect.
 272          *
 273          * @var Title
 274          */
 275         private $mRedirectedFrom = null;
 276
 277         /**
 278          * Additional key => value data
 279          */
 280         private $mProperties = [];
 281
 282         /**
 283          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 284          */
 285         private $mTarget = null;
 286
 287         /**
 288          * @var bool Whether parser output should contain table of contents
 289          */
 290         private $mEnableTOC = true;
 291
 292         /**
 293          * @var bool Whether parser output should contain section edit links
 294          */
 295         private $mEnableSectionEditLinks = true;
 296
 297         /**
 298          * @var string|null The URL to send in a <link> element with rel=copyright
 299          */
 300         private $copyrightUrl;
 301
 302         /** @var array Profiling data */
 303         private $limitReportData = [];
 304
 305         /**
 306          * Constructor for OutputPage. This should not be called directly.
 307          * Instead a new RequestContext should be created and it will implicitly create
 308          * a OutputPage tied to that context.
 309          * @param IContextSource|null $context
 310          */
 311         function __construct( IContextSource $context = null ) {
 312                 if ( $context === null ) {
 313                         # Extensions should use `new RequestContext` instead of `new OutputPage` now.
 314                         wfDeprecated( __METHOD__, '1.18' );
 315                 } else {
 316                         $this->setContext( $context );
 317                 }
 318         }
 319
 320         /**
 321          * Redirect to $url rather than displaying the normal page
 322          *
 323          * @param string $url URL
 324          * @param string $responsecode HTTP status code
 325          */
 326         public function redirect( $url, $responsecode = '302' ) {
 327                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 328                 $this->mRedirect = str_replace( "\n", '', $url );
 329                 $this->mRedirectCode = $responsecode;
 330         }
 331
 332         /**
 333          * Get the URL to redirect to, or an empty string if not redirect URL set
 334          *
 335          * @return string
 336          */
 337         public function getRedirect() {
 338                 return $this->mRedirect;
 339         }
 340
 341         /**
 342          * Set the copyright URL to send with the output.
 343          * Empty string to omit, null to reset.
 344          *
 345          * @since 1.26
 346          *
 347          * @param string|null $url
 348          */
 349         public function setCopyrightUrl( $url ) {
 350                 $this->copyrightUrl = $url;
 351         }
 352
 353         /**
 354          * Set the HTTP status code to send with the output.
 355          *
 356          * @param int $statusCode
 357          */
 358         public function setStatusCode( $statusCode ) {
 359                 $this->mStatusCode = $statusCode;
 360         }
 361
 362         /**
 363          * Add a new "<meta>" tag
 364          * To add an http-equiv meta tag, precede the name with "http:"
 365          *
 366          * @param string $name Tag name
 367          * @param string $val Tag value
 368          */
 369         function addMeta( $name, $val ) {
 370                 array_push( $this->mMetatags, [ $name, $val ] );
 371         }
 372
 373         /**
 374          * Returns the current <meta> tags
 375          *
 376          * @since 1.25
 377          * @return array
 378          */
 379         public function getMetaTags() {
 380                 return $this->mMetatags;
 381         }
 382
 383         /**
 384          * Add a new \<link\> tag to the page header.
 385          *
 386          * Note: use setCanonicalUrl() for rel=canonical.
 387          *
 388          * @param array $linkarr Associative array of attributes.
 389          */
 390         function addLink( array $linkarr ) {
 391                 array_push( $this->mLinktags, $linkarr );
 392         }
 393
 394         /**
 395          * Returns the current <link> tags
 396          *
 397          * @since 1.25
 398          * @return array
 399          */
 400         public function getLinkTags() {
 401                 return $this->mLinktags;
 402         }
 403
 404         /**
 405          * Add a new \<link\> with "rel" attribute set to "meta"
 406          *
 407          * @param array $linkarr Associative array mapping attribute names to their
 408          *                 values, both keys and values will be escaped, and the
 409          *                 "rel" attribute will be automatically added
 410          */
 411         function addMetadataLink( array $linkarr ) {
 412                 $linkarr['rel'] = $this->getMetadataAttribute();
 413                 $this->addLink( $linkarr );
 414         }
 415
 416         /**
 417          * Set the URL to be used for the <link rel=canonical>. This should be used
 418          * in preference to addLink(), to avoid duplicate link tags.
 419          * @param string $url
 420          */
 421         function setCanonicalUrl( $url ) {
 422                 $this->mCanonicalUrl = $url;
 423         }
 424
 425         /**
 426          * Returns the URL to be used for the <link rel=canonical> if
 427          * one is set.
 428          *
 429          * @since 1.25
 430          * @return bool|string
 431          */
 432         public function getCanonicalUrl() {
 433                 return $this->mCanonicalUrl;
 434         }
 435
 436         /**
 437          * Get the value of the "rel" attribute for metadata links
 438          *
 439          * @return string
 440          */
 441         public function getMetadataAttribute() {
 442                 # note: buggy CC software only reads first "meta" link
 443                 static $haveMeta = false;
 444                 if ( $haveMeta ) {
 445                         return 'alternate meta';
 446                 } else {
 447                         $haveMeta = true;
 448                         return 'meta';
 449                 }
 450         }
 451
 452         /**
 453          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 454          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 455          * if possible.
 456          *
 457          * @param string $script Raw HTML
 458          */
 459         function addScript( $script ) {
 460                 $this->mScripts .= $script;
 461         }
 462
 463         /**
 464          * Register and add a stylesheet from an extension directory.
 465          *
 466          * @deprecated since 1.27 use addModuleStyles() or addStyle() instead
 467          * @param string $url Path to sheet.  Provide either a full url (beginning
 468          *             with 'http', etc) or a relative path from the document root
 469          *             (beginning with '/').  Otherwise it behaves identically to
 470          *             addStyle() and draws from the /skins folder.
 471          */
 472         public function addExtensionStyle( $url ) {
 473                 wfDeprecated( __METHOD__, '1.27' );
 474                 array_push( $this->mExtStyles, $url );
 475         }
 476
 477         /**
 478          * Get all styles added by extensions
 479          *
 480          * @deprecated since 1.27
 481          * @return array
 482          */
 483         function getExtStyle() {
 484                 wfDeprecated( __METHOD__, '1.27' );
 485                 return $this->mExtStyles;
 486         }
 487
 488         /**
 489          * Add a JavaScript file out of skins/common, or a given relative path.
 490          * Internal use only. Use OutputPage::addModules() if possible.
 491          *
 492          * @param string $file Filename in skins/common or complete on-server path
 493          *              (/foo/bar.js)
 494          * @param string $version Style version of the file. Defaults to $wgStyleVersion
 495          */
 496         public function addScriptFile( $file, $version = null ) {
 497                 // See if $file parameter is an absolute URL or begins with a slash
 498                 if ( substr( $file, 0, 1 ) == '/' || preg_match( '#^[a-z]*://#i', $file ) ) {
 499                         $path = $file;
 500                 } else {
 501                         $path = $this->getConfig()->get( 'StylePath' ) . "/common/{$file}";
 502                 }
 503                 if ( is_null( $version ) ) {
 504                         $version = $this->getConfig()->get( 'StyleVersion' );
 505                 }
 506                 $this->addScript( Html::linkedScript( wfAppendQuery( $path, $version ) ) );
 507         }
 508
 509         /**
 510          * Add a self-contained script tag with the given contents
 511          * Internal use only. Use OutputPage::addModules() if possible.
 512          *
 513          * @param string $script JavaScript text, no script tags
 514          */
 515         public function addInlineScript( $script ) {
 516                 $this->mScripts .= Html::inlineScript( $script );
 517         }
 518
 519         /**
 520          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 521          * which are no longer registered (eg a page is cached before an extension is disabled)
 522          * @param array $modules
 523          * @param string|null $position If not null, only return modules with this position
 524          * @param string $type
 525          * @return array
 526          */
 527         protected function filterModules( array $modules, $position = null,
 528                 $type = ResourceLoaderModule::TYPE_COMBINED
 529         ) {
 530                 $resourceLoader = $this->getResourceLoader();
 531                 $filteredModules = [];
 532                 foreach ( $modules as $val ) {
 533                         $module = $resourceLoader->getModule( $val );
 534                         if ( $module instanceof ResourceLoaderModule
 535                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 536                                 && ( is_null( $position ) || $module->getPosition() == $position )
 537                                 && ( !$this->mTarget || in_array( $this->mTarget, $module->getTargets() ) )
 538                         ) {
 539                                 $filteredModules[] = $val;
 540                         }
 541                 }
 542                 return $filteredModules;
 543         }
 544
 545         /**
 546          * Get the list of modules to include on this page
 547          *
 548          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 549          * @param string|null $position If not null, only return modules with this position
 550          * @param string $param
 551          * @return array Array of module names
 552          */
 553         public function getModules( $filter = false, $position = null, $param = 'mModules',
 554                 $type = ResourceLoaderModule::TYPE_COMBINED
 555         ) {
 556                 $modules = array_values( array_unique( $this->$param ) );
 557                 return $filter
 558                         ? $this->filterModules( $modules, $position, $type )
 559                         : $modules;
 560         }
 561
 562         /**
 563          * Add one or more modules recognized by ResourceLoader. Modules added
 564          * through this function will be loaded by ResourceLoader when the
 565          * page loads.
 566          *
 567          * @param string|array $modules Module name (string) or array of module names
 568          */
 569         public function addModules( $modules ) {
 570                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 571         }
 572
 573         /**
 574          * Get the list of module JS to include on this page
 575          *
 576          * @param bool $filter
 577          * @param string|null $position
 578          * @return array Array of module names
 579          */
 580         public function getModuleScripts( $filter = false, $position = null ) {
 581                 return $this->getModules( $filter, $position, 'mModuleScripts',
 582                         ResourceLoaderModule::TYPE_SCRIPTS
 583                 );
 584         }
 585
 586         /**
 587          * Add only JS of one or more modules recognized by ResourceLoader. Module
 588          * scripts added through this function will be loaded by ResourceLoader when
 589          * the page loads.
 590          *
 591          * @param string|array $modules Module name (string) or array of module names
 592          */
 593         public function addModuleScripts( $modules ) {
 594                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 595         }
 596
 597         /**
 598          * Get the list of module CSS to include on this page
 599          *
 600          * @param bool $filter
 601          * @param string|null $position
 602          * @return array Array of module names
 603          */
 604         public function getModuleStyles( $filter = false, $position = null ) {
 605                 return $this->getModules( $filter, $position, 'mModuleStyles',
 606                         ResourceLoaderModule::TYPE_STYLES
 607                 );
 608         }
 609
 610         /**
 611          * Add only CSS of one or more modules recognized by ResourceLoader.
 612          *
 613          * Module styles added through this function will be added using standard link CSS
 614          * tags, rather than as a combined Javascript and CSS package. Thus, they will
 615          * load when JavaScript is disabled (unless CSS also happens to be disabled).
 616          *
 617          * @param string|array $modules Module name (string) or array of module names
 618          */
 619         public function addModuleStyles( $modules ) {
 620                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 621         }
 622
 623         /**
 624          * @return null|string ResourceLoader target
 625          */
 626         public function getTarget() {
 627                 return $this->mTarget;
 628         }
 629
 630         /**
 631          * Sets ResourceLoader target for load.php links. If null, will be omitted
 632          *
 633          * @param string|null $target
 634          */
 635         public function setTarget( $target ) {
 636                 $this->mTarget = $target;
 637         }
 638
 639         /**
 640          * Get an array of head items
 641          *
 642          * @return array
 643          */
 644         function getHeadItemsArray() {
 645                 return $this->mHeadItems;
 646         }
 647
 648         /**
 649          * Add or replace an header item to the output
 650          *
 651          * Whenever possible, use more specific options like ResourceLoader modules,
 652          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 653          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 654          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 655          * This would be your very LAST fallback.
 656          *
 657          * @param string $name Item name
 658          * @param string $value Raw HTML
 659          */
 660         public function addHeadItem( $name, $value ) {
 661                 $this->mHeadItems[$name] = $value;
 662         }
 663
 664         /**
 665          * Check if the header item $name is already set
 666          *
 667          * @param string $name Item name
 668          * @return bool
 669          */
 670         public function hasHeadItem( $name ) {
 671                 return isset( $this->mHeadItems[$name] );
 672         }
 673
 674         /**
 675          * @deprecated since 1.28 Obsolete - wgUseETag experiment was removed.
 676          * @param string $tag
 677          */
 678         public function setETag( $tag ) {
 679         }
 680
 681         /**
 682          * Set whether the output should only contain the body of the article,
 683          * without any skin, sidebar, etc.
 684          * Used e.g. when calling with "action=render".
 685          *
 686          * @param bool $only Whether to output only the body of the article
 687          */
 688         public function setArticleBodyOnly( $only ) {
 689                 $this->mArticleBodyOnly = $only;
 690         }
 691
 692         /**
 693          * Return whether the output will contain only the body of the article
 694          *
 695          * @return bool
 696          */
 697         public function getArticleBodyOnly() {
 698                 return $this->mArticleBodyOnly;
 699         }
 700
 701         /**
 702          * Set an additional output property
 703          * @since 1.21
 704          *
 705          * @param string $name
 706          * @param mixed $value
 707          */
 708         public function setProperty( $name, $value ) {
 709                 $this->mProperties[$name] = $value;
 710         }
 711
 712         /**
 713          * Get an additional output property
 714          * @since 1.21
 715          *
 716          * @param string $name
 717          * @return mixed Property value or null if not found
 718          */
 719         public function getProperty( $name ) {
 720                 if ( isset( $this->mProperties[$name] ) ) {
 721                         return $this->mProperties[$name];
 722                 } else {
 723                         return null;
 724                 }
 725         }
 726
 727         /**
 728          * checkLastModified tells the client to use the client-cached page if
 729          * possible. If successful, the OutputPage is disabled so that
 730          * any future call to OutputPage->output() have no effect.
 731          *
 732          * Side effect: sets mLastModified for Last-Modified header
 733          *
 734          * @param string $timestamp
 735          *
 736          * @return bool True if cache-ok headers was sent.
 737          */
 738         public function checkLastModified( $timestamp ) {
 739                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 740                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 741                         return false;
 742                 }
 743                 $config = $this->getConfig();
 744                 if ( !$config->get( 'CachePages' ) ) {
 745                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 746                         return false;
 747                 }
 748
 749                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 750                 $modifiedTimes = [
 751                         'page' => $timestamp,
 752                         'user' => $this->getUser()->getTouched(),
 753                         'epoch' => $config->get( 'CacheEpoch' )
 754                 ];
 755                 if ( $config->get( 'UseSquid' ) ) {
 756                         // bug 44570: the core page itself may not change, but resources might
 757                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, time() - $config->get( 'SquidMaxage' ) );
 758                 }
 759                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 760
 761                 $maxModified = max( $modifiedTimes );
 762                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 763
 764                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 765                 if ( $clientHeader === false ) {
 766                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 767                         return false;
 768                 }
 769
 770                 # IE sends sizes after the date like this:
 771                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 772                 # this breaks strtotime().
 773                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 774
 775                 MediaWiki\suppressWarnings(); // E_STRICT system time bitching
 776                 $clientHeaderTime = strtotime( $clientHeader );
 777                 MediaWiki\restoreWarnings();
 778                 if ( !$clientHeaderTime ) {
 779                         wfDebug( __METHOD__
 780                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 781                         return false;
 782                 }
 783                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 784
 785                 # Make debug info
 786                 $info = '';
 787                 foreach ( $modifiedTimes as $name => $value ) {
 788                         if ( $info !== '' ) {
 789                                 $info .= ', ';
 790                         }
 791                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 792                 }
 793
 794                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 795                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 796                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 797                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 798                 if ( $clientHeaderTime < $maxModified ) {
 799                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 800                         return false;
 801                 }
 802
 803                 # Not modified
 804                 # Give a 304 Not Modified response code and disable body output
 805                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 806                 ini_set( 'zlib.output_compression', 0 );
 807                 $this->getRequest()->response()->statusHeader( 304 );
 808                 $this->sendCacheControl();
 809                 $this->disable();
 810
 811                 // Don't output a compressed blob when using ob_gzhandler;
 812                 // it's technically against HTTP spec and seems to confuse
 813                 // Firefox when the response gets split over two packets.
 814                 wfClearOutputBuffers();
 815
 816                 return true;
 817         }
 818
 819         /**
 820          * Override the last modified timestamp
 821          *
 822          * @param string $timestamp New timestamp, in a format readable by
 823          *        wfTimestamp()
 824          */
 825         public function setLastModified( $timestamp ) {
 826                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 827         }
 828
 829         /**
 830          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 831          *
 832          * @param string $policy The literal string to output as the contents of
 833          *   the meta tag.  Will be parsed according to the spec and output in
 834          *   standardized form.
 835          * @return null
 836          */
 837         public function setRobotPolicy( $policy ) {
 838                 $policy = Article::formatRobotPolicy( $policy );
 839
 840                 if ( isset( $policy['index'] ) ) {
 841                         $this->setIndexPolicy( $policy['index'] );
 842                 }
 843                 if ( isset( $policy['follow'] ) ) {
 844                         $this->setFollowPolicy( $policy['follow'] );
 845                 }
 846         }
 847
 848         /**
 849          * Set the index policy for the page, but leave the follow policy un-
 850          * touched.
 851          *
 852          * @param string $policy Either 'index' or 'noindex'.
 853          * @return null
 854          */
 855         public function setIndexPolicy( $policy ) {
 856                 $policy = trim( $policy );
 857                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 858                         $this->mIndexPolicy = $policy;
 859                 }
 860         }
 861
 862         /**
 863          * Set the follow policy for the page, but leave the index policy un-
 864          * touched.
 865          *
 866          * @param string $policy Either 'follow' or 'nofollow'.
 867          * @return null
 868          */
 869         public function setFollowPolicy( $policy ) {
 870                 $policy = trim( $policy );
 871                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 872                         $this->mFollowPolicy = $policy;
 873                 }
 874         }
 875
 876         /**
 877          * Set the new value of the "action text", this will be added to the
 878          * "HTML title", separated from it with " - ".
 879          *
 880          * @param string $text New value of the "action text"
 881          */
 882         public function setPageTitleActionText( $text ) {
 883                 $this->mPageTitleActionText = $text;
 884         }
 885
 886         /**
 887          * Get the value of the "action text"
 888          *
 889          * @return string
 890          */
 891         public function getPageTitleActionText() {
 892                 return $this->mPageTitleActionText;
 893         }
 894
 895         /**
 896          * "HTML title" means the contents of "<title>".
 897          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 898          *
 899          * @param string|Message $name
 900          */
 901         public function setHTMLTitle( $name ) {
 902                 if ( $name instanceof Message ) {
 903                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 904                 } else {
 905                         $this->mHTMLtitle = $name;
 906                 }
 907         }
 908
 909         /**
 910          * Return the "HTML title", i.e. the content of the "<title>" tag.
 911          *
 912          * @return string
 913          */
 914         public function getHTMLTitle() {
 915                 return $this->mHTMLtitle;
 916         }
 917
 918         /**
 919          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 920          *
 921          * @param Title $t
 922          */
 923         public function setRedirectedFrom( $t ) {
 924                 $this->mRedirectedFrom = $t;
 925         }
 926
 927         /**
 928          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 929          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 930          * but not bad tags like \<script\>. This function automatically sets
 931          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 932          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 933          * good tags like \<i\> will be dropped entirely.
 934          *
 935          * @param string|Message $name
 936          */
 937         public function setPageTitle( $name ) {
 938                 if ( $name instanceof Message ) {
 939                         $name = $name->setContext( $this->getContext() )->text();
 940                 }
 941
 942                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 943                 # but leave "<i>foobar</i>" alone
 944                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 945                 $this->mPagetitle = $nameWithTags;
 946
 947                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 948                 $this->setHTMLTitle(
 949                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 950                                 ->inContentLanguage()
 951                 );
 952         }
 953
 954         /**
 955          * Return the "page title", i.e. the content of the \<h1\> tag.
 956          *
 957          * @return string
 958          */
 959         public function getPageTitle() {
 960                 return $this->mPagetitle;
 961         }
 962
 963         /**
 964          * Set the Title object to use
 965          *
 966          * @param Title $t
 967          */
 968         public function setTitle( Title $t ) {
 969                 $this->getContext()->setTitle( $t );
 970         }
 971
 972         /**
 973          * Replace the subtitle with $str
 974          *
 975          * @param string|Message $str New value of the subtitle. String should be safe HTML.
 976          */
 977         public function setSubtitle( $str ) {
 978                 $this->clearSubtitle();
 979                 $this->addSubtitle( $str );
 980         }
 981
 982         /**
 983          * Add $str to the subtitle
 984          *
 985          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
 986          */
 987         public function addSubtitle( $str ) {
 988                 if ( $str instanceof Message ) {
 989                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
 990                 } else {
 991                         $this->mSubtitle[] = $str;
 992                 }
 993         }
 994
 995         /**
 996          * Build message object for a subtitle containing a backlink to a page
 997          *
 998          * @param Title $title Title to link to
 999          * @param array $query Array of additional parameters to include in the link
1000          * @return Message
1001          * @since 1.25
1002          */
1003         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1004                 if ( $title->isRedirect() ) {
1005                         $query['redirect'] = 'no';
1006                 }
1007                 return wfMessage( 'backlinksubtitle' )
1008                         ->rawParams( Linker::link( $title, null, [], $query ) );
1009         }
1010
1011         /**
1012          * Add a subtitle containing a backlink to a page
1013          *
1014          * @param Title $title Title to link to
1015          * @param array $query Array of additional parameters to include in the link
1016          */
1017         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1018                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1019         }
1020
1021         /**
1022          * Clear the subtitles
1023          */
1024         public function clearSubtitle() {
1025                 $this->mSubtitle = [];
1026         }
1027
1028         /**
1029          * Get the subtitle
1030          *
1031          * @return string
1032          */
1033         public function getSubtitle() {
1034                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1035         }
1036
1037         /**
1038          * Set the page as printable, i.e. it'll be displayed with all
1039          * print styles included
1040          */
1041         public function setPrintable() {
1042                 $this->mPrintable = true;
1043         }
1044
1045         /**
1046          * Return whether the page is "printable"
1047          *
1048          * @return bool
1049          */
1050         public function isPrintable() {
1051                 return $this->mPrintable;
1052         }
1053
1054         /**
1055          * Disable output completely, i.e. calling output() will have no effect
1056          */
1057         public function disable() {
1058                 $this->mDoNothing = true;
1059         }
1060
1061         /**
1062          * Return whether the output will be completely disabled
1063          *
1064          * @return bool
1065          */
1066         public function isDisabled() {
1067                 return $this->mDoNothing;
1068         }
1069
1070         /**
1071          * Show an "add new section" link?
1072          *
1073          * @return bool
1074          */
1075         public function showNewSectionLink() {
1076                 return $this->mNewSectionLink;
1077         }
1078
1079         /**
1080          * Forcibly hide the new section link?
1081          *
1082          * @return bool
1083          */
1084         public function forceHideNewSectionLink() {
1085                 return $this->mHideNewSectionLink;
1086         }
1087
1088         /**
1089          * Add or remove feed links in the page header
1090          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1091          * for the new version
1092          * @see addFeedLink()
1093          *
1094          * @param bool $show True: add default feeds, false: remove all feeds
1095          */
1096         public function setSyndicated( $show = true ) {
1097                 if ( $show ) {
1098                         $this->setFeedAppendQuery( false );
1099                 } else {
1100                         $this->mFeedLinks = [];
1101                 }
1102         }
1103
1104         /**
1105          * Add default feeds to the page header
1106          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1107          * for the new version
1108          * @see addFeedLink()
1109          *
1110          * @param string $val Query to append to feed links or false to output
1111          *        default links
1112          */
1113         public function setFeedAppendQuery( $val ) {
1114                 $this->mFeedLinks = [];
1115
1116                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1117                         $query = "feed=$type";
1118                         if ( is_string( $val ) ) {
1119                                 $query .= '&' . $val;
1120                         }
1121                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1122                 }
1123         }
1124
1125         /**
1126          * Add a feed link to the page header
1127          *
1128          * @param string $format Feed type, should be a key of $wgFeedClasses
1129          * @param string $href URL
1130          */
1131         public function addFeedLink( $format, $href ) {
1132                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1133                         $this->mFeedLinks[$format] = $href;
1134                 }
1135         }
1136
1137         /**
1138          * Should we output feed links for this page?
1139          * @return bool
1140          */
1141         public function isSyndicated() {
1142                 return count( $this->mFeedLinks ) > 0;
1143         }
1144
1145         /**
1146          * Return URLs for each supported syndication format for this page.
1147          * @return array Associating format keys with URLs
1148          */
1149         public function getSyndicationLinks() {
1150                 return $this->mFeedLinks;
1151         }
1152
1153         /**
1154          * Will currently always return null
1155          *
1156          * @return null
1157          */
1158         public function getFeedAppendQuery() {
1159                 return $this->mFeedLinksAppendQuery;
1160         }
1161
1162         /**
1163          * Set whether the displayed content is related to the source of the
1164          * corresponding article on the wiki
1165          * Setting true will cause the change "article related" toggle to true
1166          *
1167          * @param bool $v
1168          */
1169         public function setArticleFlag( $v ) {
1170                 $this->mIsarticle = $v;
1171                 if ( $v ) {
1172                         $this->mIsArticleRelated = $v;
1173                 }
1174         }
1175
1176         /**
1177          * Return whether the content displayed page is related to the source of
1178          * the corresponding article on the wiki
1179          *
1180          * @return bool
1181          */
1182         public function isArticle() {
1183                 return $this->mIsarticle;
1184         }
1185
1186         /**
1187          * Set whether this page is related an article on the wiki
1188          * Setting false will cause the change of "article flag" toggle to false
1189          *
1190          * @param bool $v
1191          */
1192         public function setArticleRelated( $v ) {
1193                 $this->mIsArticleRelated = $v;
1194                 if ( !$v ) {
1195                         $this->mIsarticle = false;
1196                 }
1197         }
1198
1199         /**
1200          * Return whether this page is related an article on the wiki
1201          *
1202          * @return bool
1203          */
1204         public function isArticleRelated() {
1205                 return $this->mIsArticleRelated;
1206         }
1207
1208         /**
1209          * Add new language links
1210          *
1211          * @param array $newLinkArray Associative array mapping language code to the page
1212          *                      name
1213          */
1214         public function addLanguageLinks( array $newLinkArray ) {
1215                 $this->mLanguageLinks += $newLinkArray;
1216         }
1217
1218         /**
1219          * Reset the language links and add new language links
1220          *
1221          * @param array $newLinkArray Associative array mapping language code to the page
1222          *                      name
1223          */
1224         public function setLanguageLinks( array $newLinkArray ) {
1225                 $this->mLanguageLinks = $newLinkArray;
1226         }
1227
1228         /**
1229          * Get the list of language links
1230          *
1231          * @return array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page')
1232          */
1233         public function getLanguageLinks() {
1234                 return $this->mLanguageLinks;
1235         }
1236
1237         /**
1238          * Add an array of categories, with names in the keys
1239          *
1240          * @param array $categories Mapping category name => sort key
1241          */
1242         public function addCategoryLinks( array $categories ) {
1243                 global $wgContLang;
1244
1245                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1246                         return;
1247                 }
1248
1249                 # Add the links to a LinkBatch
1250                 $arr = [ NS_CATEGORY => $categories ];
1251                 $lb = new LinkBatch;
1252                 $lb->setArray( $arr );
1253
1254                 # Fetch existence plus the hiddencat property
1255                 $dbr = wfGetDB( DB_SLAVE );
1256                 $fields = array_merge(
1257                         LinkCache::getSelectFields(),
1258                         [ 'page_namespace', 'page_title', 'pp_value' ]
1259                 );
1260
1261                 $res = $dbr->select( [ 'page', 'page_props' ],
1262                         $fields,
1263                         $lb->constructSet( 'page', $dbr ),
1264                         __METHOD__,
1265                         [],
1266                         [ 'page_props' => [ 'LEFT JOIN', [
1267                                 'pp_propname' => 'hiddencat',
1268                                 'pp_page = page_id'
1269                         ] ] ]
1270                 );
1271
1272                 # Add the results to the link cache
1273                 $lb->addResultToCache( LinkCache::singleton(), $res );
1274
1275                 # Set all the values to 'normal'.
1276                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1277
1278                 # Mark hidden categories
1279                 foreach ( $res as $row ) {
1280                         if ( isset( $row->pp_value ) ) {
1281                                 $categories[$row->page_title] = 'hidden';
1282                         }
1283                 }
1284
1285                 # Add the remaining categories to the skin
1286                 if ( Hooks::run(
1287                         'OutputPageMakeCategoryLinks',
1288                         [ &$this, $categories, &$this->mCategoryLinks ] )
1289                 ) {
1290                         foreach ( $categories as $category => $type ) {
1291                                 // array keys will cast numeric category names to ints, so cast back to string
1292                                 $category = (string)$category;
1293                                 $origcategory = $category;
1294                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1295                                 if ( !$title ) {
1296                                         continue;
1297                                 }
1298                                 $wgContLang->findVariantLink( $category, $title, true );
1299                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1300                                         continue;
1301                                 }
1302                                 $text = $wgContLang->convertHtml( $title->getText() );
1303                                 $this->mCategories[] = $title->getText();
1304                                 $this->mCategoryLinks[$type][] = Linker::link( $title, $text );
1305                         }
1306                 }
1307         }
1308
1309         /**
1310          * Reset the category links (but not the category list) and add $categories
1311          *
1312          * @param array $categories Mapping category name => sort key
1313          */
1314         public function setCategoryLinks( array $categories ) {
1315                 $this->mCategoryLinks = [];
1316                 $this->addCategoryLinks( $categories );
1317         }
1318
1319         /**
1320          * Get the list of category links, in a 2-D array with the following format:
1321          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1322          * hidden categories) and $link a HTML fragment with a link to the category
1323          * page
1324          *
1325          * @return array
1326          */
1327         public function getCategoryLinks() {
1328                 return $this->mCategoryLinks;
1329         }
1330
1331         /**
1332          * Get the list of category names this page belongs to
1333          *
1334          * @return array Array of strings
1335          */
1336         public function getCategories() {
1337                 return $this->mCategories;
1338         }
1339
1340         /**
1341          * Add an array of indicators, with their identifiers as array
1342          * keys and HTML contents as values.
1343          *
1344          * In case of duplicate keys, existing values are overwritten.
1345          *
1346          * @param array $indicators
1347          * @since 1.25
1348          */
1349         public function setIndicators( array $indicators ) {
1350                 $this->mIndicators = $indicators + $this->mIndicators;
1351                 // Keep ordered by key
1352                 ksort( $this->mIndicators );
1353         }
1354
1355         /**
1356          * Get the indicators associated with this page.
1357          *
1358          * The array will be internally ordered by item keys.
1359          *
1360          * @return array Keys: identifiers, values: HTML contents
1361          * @since 1.25
1362          */
1363         public function getIndicators() {
1364                 return $this->mIndicators;
1365         }
1366
1367         /**
1368          * Adds help link with an icon via page indicators.
1369          * Link target can be overridden by a local message containing a wikilink:
1370          * the message key is: lowercase action or special page name + '-helppage'.
1371          * @param string $to Target MediaWiki.org page title or encoded URL.
1372          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1373          * @since 1.25
1374          */
1375         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1376                 $this->addModuleStyles( 'mediawiki.helplink' );
1377                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1378
1379                 if ( $overrideBaseUrl ) {
1380                         $helpUrl = $to;
1381                 } else {
1382                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1383                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1384                 }
1385
1386                 $link = Html::rawElement(
1387                         'a',
1388                         [
1389                                 'href' => $helpUrl,
1390                                 'target' => '_blank',
1391                                 'class' => 'mw-helplink',
1392                         ],
1393                         $text
1394                 );
1395
1396                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1397         }
1398
1399         /**
1400          * Do not allow scripts which can be modified by wiki users to load on this page;
1401          * only allow scripts bundled with, or generated by, the software.
1402          * Site-wide styles are controlled by a config setting, since they can be
1403          * used to create a custom skin/theme, but not user-specific ones.
1404          *
1405          * @todo this should be given a more accurate name
1406          */
1407         public function disallowUserJs() {
1408                 $this->reduceAllowedModules(
1409                         ResourceLoaderModule::TYPE_SCRIPTS,
1410                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1411                 );
1412
1413                 // Site-wide styles are controlled by a config setting, see bug 71621
1414                 // for background on why. User styles are never allowed.
1415                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1416                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1417                 } else {
1418                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1419                 }
1420                 $this->reduceAllowedModules(
1421                         ResourceLoaderModule::TYPE_STYLES,
1422                         $styleOrigin
1423                 );
1424         }
1425
1426         /**
1427          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1428          * @see ResourceLoaderModule::$origin
1429          * @param string $type ResourceLoaderModule TYPE_ constant
1430          * @return int ResourceLoaderModule ORIGIN_ class constant
1431          */
1432         public function getAllowedModules( $type ) {
1433                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1434                         return min( array_values( $this->mAllowedModules ) );
1435                 } else {
1436                         return isset( $this->mAllowedModules[$type] )
1437                                 ? $this->mAllowedModules[$type]
1438                                 : ResourceLoaderModule::ORIGIN_ALL;
1439                 }
1440         }
1441
1442         /**
1443          * Limit the highest level of CSS/JS untrustworthiness allowed.
1444          *
1445          * If passed the same or a higher level than the current level of untrustworthiness set, the
1446          * level will remain unchanged.
1447          *
1448          * @param string $type
1449          * @param int $level ResourceLoaderModule class constant
1450          */
1451         public function reduceAllowedModules( $type, $level ) {
1452                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1453         }
1454
1455         /**
1456          * Prepend $text to the body HTML
1457          *
1458          * @param string $text HTML
1459          */
1460         public function prependHTML( $text ) {
1461                 $this->mBodytext = $text . $this->mBodytext;
1462         }
1463
1464         /**
1465          * Append $text to the body HTML
1466          *
1467          * @param string $text HTML
1468          */
1469         public function addHTML( $text ) {
1470                 $this->mBodytext .= $text;
1471         }
1472
1473         /**
1474          * Shortcut for adding an Html::element via addHTML.
1475          *
1476          * @since 1.19
1477          *
1478          * @param string $element
1479          * @param array $attribs
1480          * @param string $contents
1481          */
1482         public function addElement( $element, array $attribs = [], $contents = '' ) {
1483                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1484         }
1485
1486         /**
1487          * Clear the body HTML
1488          */
1489         public function clearHTML() {
1490                 $this->mBodytext = '';
1491         }
1492
1493         /**
1494          * Get the body HTML
1495          *
1496          * @return string HTML
1497          */
1498         public function getHTML() {
1499                 return $this->mBodytext;
1500         }
1501
1502         /**
1503          * Get/set the ParserOptions object to use for wikitext parsing
1504          *
1505          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1506          *   current ParserOption object
1507          * @return ParserOptions
1508          */
1509         public function parserOptions( $options = null ) {
1510                 if ( $options !== null && !empty( $options->isBogus ) ) {
1511                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1512                         // been changed somehow, and keep it if so.
1513                         $anonPO = ParserOptions::newFromAnon();
1514                         $anonPO->setEditSection( false );
1515                         if ( !$options->matches( $anonPO ) ) {
1516                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1517                                 $options->isBogus = false;
1518                         }
1519                 }
1520
1521                 if ( !$this->mParserOptions ) {
1522                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1523                                 // $wgUser isn't unstubbable yet, so don't try to get a
1524                                 // ParserOptions for it. And don't cache this ParserOptions
1525                                 // either.
1526                                 $po = ParserOptions::newFromAnon();
1527                                 $po->setEditSection( false );
1528                                 $po->isBogus = true;
1529                                 if ( $options !== null ) {
1530                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1531                                 }
1532                                 return $po;
1533                         }
1534
1535                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1536                         $this->mParserOptions->setEditSection( false );
1537                 }
1538
1539                 if ( $options !== null && !empty( $options->isBogus ) ) {
1540                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1541                         // thing.
1542                         return wfSetVar( $this->mParserOptions, null, true );
1543                 } else {
1544                         return wfSetVar( $this->mParserOptions, $options );
1545                 }
1546         }
1547
1548         /**
1549          * Set the revision ID which will be seen by the wiki text parser
1550          * for things such as embedded {{REVISIONID}} variable use.
1551          *
1552          * @param int|null $revid An positive integer, or null
1553          * @return mixed Previous value
1554          */
1555         public function setRevisionId( $revid ) {
1556                 $val = is_null( $revid ) ? null : intval( $revid );
1557                 return wfSetVar( $this->mRevisionId, $val );
1558         }
1559
1560         /**
1561          * Get the displayed revision ID
1562          *
1563          * @return int
1564          */
1565         public function getRevisionId() {
1566                 return $this->mRevisionId;
1567         }
1568
1569         /**
1570          * Set the timestamp of the revision which will be displayed. This is used
1571          * to avoid a extra DB call in Skin::lastModified().
1572          *
1573          * @param string|null $timestamp
1574          * @return mixed Previous value
1575          */
1576         public function setRevisionTimestamp( $timestamp ) {
1577                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1578         }
1579
1580         /**
1581          * Get the timestamp of displayed revision.
1582          * This will be null if not filled by setRevisionTimestamp().
1583          *
1584          * @return string|null
1585          */
1586         public function getRevisionTimestamp() {
1587                 return $this->mRevisionTimestamp;
1588         }
1589
1590         /**
1591          * Set the displayed file version
1592          *
1593          * @param File|bool $file
1594          * @return mixed Previous value
1595          */
1596         public function setFileVersion( $file ) {
1597                 $val = null;
1598                 if ( $file instanceof File && $file->exists() ) {
1599                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1600                 }
1601                 return wfSetVar( $this->mFileVersion, $val, true );
1602         }
1603
1604         /**
1605          * Get the displayed file version
1606          *
1607          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1608          */
1609         public function getFileVersion() {
1610                 return $this->mFileVersion;
1611         }
1612
1613         /**
1614          * Get the templates used on this page
1615          *
1616          * @return array (namespace => dbKey => revId)
1617          * @since 1.18
1618          */
1619         public function getTemplateIds() {
1620                 return $this->mTemplateIds;
1621         }
1622
1623         /**
1624          * Get the files used on this page
1625          *
1626          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1627          * @since 1.18
1628          */
1629         public function getFileSearchOptions() {
1630                 return $this->mImageTimeKeys;
1631         }
1632
1633         /**
1634          * Convert wikitext to HTML and add it to the buffer
1635          * Default assumes that the current page title will be used.
1636          *
1637          * @param string $text
1638          * @param bool $linestart Is this the start of a line?
1639          * @param bool $interface Is this text in the user interface language?
1640          * @throws MWException
1641          */
1642         public function addWikiText( $text, $linestart = true, $interface = true ) {
1643                 $title = $this->getTitle(); // Work around E_STRICT
1644                 if ( !$title ) {
1645                         throw new MWException( 'Title is null' );
1646                 }
1647                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1648         }
1649
1650         /**
1651          * Add wikitext with a custom Title object
1652          *
1653          * @param string $text Wikitext
1654          * @param Title $title
1655          * @param bool $linestart Is this the start of a line?
1656          */
1657         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1658                 $this->addWikiTextTitle( $text, $title, $linestart );
1659         }
1660
1661         /**
1662          * Add wikitext with a custom Title object and tidy enabled.
1663          *
1664          * @param string $text Wikitext
1665          * @param Title $title
1666          * @param bool $linestart Is this the start of a line?
1667          */
1668         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1669                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1670         }
1671
1672         /**
1673          * Add wikitext with tidy enabled
1674          *
1675          * @param string $text Wikitext
1676          * @param bool $linestart Is this the start of a line?
1677          */
1678         public function addWikiTextTidy( $text, $linestart = true ) {
1679                 $title = $this->getTitle();
1680                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1681         }
1682
1683         /**
1684          * Add wikitext with a custom Title object
1685          *
1686          * @param string $text Wikitext
1687          * @param Title $title
1688          * @param bool $linestart Is this the start of a line?
1689          * @param bool $tidy Whether to use tidy
1690          * @param bool $interface Whether it is an interface message
1691          *   (for example disables conversion)
1692          */
1693         public function addWikiTextTitle( $text, Title $title, $linestart,
1694                 $tidy = false, $interface = false
1695         ) {
1696                 global $wgParser;
1697
1698                 $popts = $this->parserOptions();
1699                 $oldTidy = $popts->setTidy( $tidy );
1700                 $popts->setInterfaceMessage( (bool)$interface );
1701
1702                 $parserOutput = $wgParser->getFreshParser()->parse(
1703                         $text, $title, $popts,
1704                         $linestart, true, $this->mRevisionId
1705                 );
1706
1707                 $popts->setTidy( $oldTidy );
1708
1709                 $this->addParserOutput( $parserOutput );
1710
1711         }
1712
1713         /**
1714          * Add a ParserOutput object, but without Html.
1715          *
1716          * @deprecated since 1.24, use addParserOutputMetadata() instead.
1717          * @param ParserOutput $parserOutput
1718          */
1719         public function addParserOutputNoText( $parserOutput ) {
1720                 wfDeprecated( __METHOD__, '1.24' );
1721                 $this->addParserOutputMetadata( $parserOutput );
1722         }
1723
1724         /**
1725          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1726          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1727          * and so on.
1728          *
1729          * @since 1.24
1730          * @param ParserOutput $parserOutput
1731          */
1732         public function addParserOutputMetadata( $parserOutput ) {
1733                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1734                 $this->addCategoryLinks( $parserOutput->getCategories() );
1735                 $this->setIndicators( $parserOutput->getIndicators() );
1736                 $this->mNewSectionLink = $parserOutput->getNewSection();
1737                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1738
1739                 if ( !$parserOutput->isCacheable() ) {
1740                         $this->enableClientCache( false );
1741                 }
1742                 $this->mNoGallery = $parserOutput->getNoGallery();
1743                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1744                 $this->addModules( $parserOutput->getModules() );
1745                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1746                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1747                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1748                 $this->mPreventClickjacking = $this->mPreventClickjacking
1749                         || $parserOutput->preventClickjacking();
1750
1751                 // Template versioning...
1752                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1753                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1754                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1755                         } else {
1756                                 $this->mTemplateIds[$ns] = $dbks;
1757                         }
1758                 }
1759                 // File versioning...
1760                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1761                         $this->mImageTimeKeys[$dbk] = $data;
1762                 }
1763
1764                 // Hooks registered in the object
1765                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1766                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1767                         list( $hookName, $data ) = $hookInfo;
1768                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1769                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1770                         }
1771                 }
1772
1773                 // Enable OOUI if requested via ParserOutput
1774                 if ( $parserOutput->getEnableOOUI() ) {
1775                         $this->enableOOUI();
1776                 }
1777
1778                 // Include profiling data
1779                 $this->limitReportData = $parserOutput->getLimitReportData();
1780
1781                 // Link flags are ignored for now, but may in the future be
1782                 // used to mark individual language links.
1783                 $linkFlags = [];
1784                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1785                 Hooks::run( 'OutputPageParserOutput', [ &$this, $parserOutput ] );
1786         }
1787
1788         /**
1789          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1790          * ParserOutput object, without any other metadata.
1791          *
1792          * @since 1.24
1793          * @param ParserOutput $parserOutput
1794          */
1795         public function addParserOutputContent( $parserOutput ) {
1796                 $this->addParserOutputText( $parserOutput );
1797
1798                 $this->addModules( $parserOutput->getModules() );
1799                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1800                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1801
1802                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1803         }
1804
1805         /**
1806          * Add the HTML associated with a ParserOutput object, without any metadata.
1807          *
1808          * @since 1.24
1809          * @param ParserOutput $parserOutput
1810          */
1811         public function addParserOutputText( $parserOutput ) {
1812                 $text = $parserOutput->getText();
1813                 Hooks::run( 'OutputPageBeforeHTML', [ &$this, &$text ] );
1814                 $this->addHTML( $text );
1815         }
1816
1817         /**
1818          * Add everything from a ParserOutput object.
1819          *
1820          * @param ParserOutput $parserOutput
1821          */
1822         function addParserOutput( $parserOutput ) {
1823                 $this->addParserOutputMetadata( $parserOutput );
1824                 $parserOutput->setTOCEnabled( $this->mEnableTOC );
1825
1826                 // Touch section edit links only if not previously disabled
1827                 if ( $parserOutput->getEditSectionTokens() ) {
1828                         $parserOutput->setEditSectionTokens( $this->mEnableSectionEditLinks );
1829                 }
1830
1831                 $this->addParserOutputText( $parserOutput );
1832         }
1833
1834         /**
1835          * Add the output of a QuickTemplate to the output buffer
1836          *
1837          * @param QuickTemplate $template
1838          */
1839         public function addTemplate( &$template ) {
1840                 $this->addHTML( $template->getHTML() );
1841         }
1842
1843         /**
1844          * Parse wikitext and return the HTML.
1845          *
1846          * @param string $text
1847          * @param bool $linestart Is this the start of a line?
1848          * @param bool $interface Use interface language ($wgLang instead of
1849          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1850          *   This also disables LanguageConverter.
1851          * @param Language $language Target language object, will override $interface
1852          * @throws MWException
1853          * @return string HTML
1854          */
1855         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1856                 global $wgParser;
1857
1858                 if ( is_null( $this->getTitle() ) ) {
1859                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1860                 }
1861
1862                 $popts = $this->parserOptions();
1863                 if ( $interface ) {
1864                         $popts->setInterfaceMessage( true );
1865                 }
1866                 if ( $language !== null ) {
1867                         $oldLang = $popts->setTargetLanguage( $language );
1868                 }
1869
1870                 $parserOutput = $wgParser->getFreshParser()->parse(
1871                         $text, $this->getTitle(), $popts,
1872                         $linestart, true, $this->mRevisionId
1873                 );
1874
1875                 if ( $interface ) {
1876                         $popts->setInterfaceMessage( false );
1877                 }
1878                 if ( $language !== null ) {
1879                         $popts->setTargetLanguage( $oldLang );
1880                 }
1881
1882                 return $parserOutput->getText();
1883         }
1884
1885         /**
1886          * Parse wikitext, strip paragraphs, and return the HTML.
1887          *
1888          * @param string $text
1889          * @param bool $linestart Is this the start of a line?
1890          * @param bool $interface Use interface language ($wgLang instead of
1891          *   $wgContLang) while parsing language sensitive magic
1892          *   words like GRAMMAR and PLURAL
1893          * @return string HTML
1894          */
1895         public function parseInline( $text, $linestart = true, $interface = false ) {
1896                 $parsed = $this->parse( $text, $linestart, $interface );
1897                 return Parser::stripOuterParagraph( $parsed );
1898         }
1899
1900         /**
1901          * @param $maxage
1902          * @deprecated since 1.27 Use setCdnMaxage() instead
1903          */
1904         public function setSquidMaxage( $maxage ) {
1905                 $this->setCdnMaxage( $maxage );
1906         }
1907
1908         /**
1909          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1910          *
1911          * @param int $maxage Maximum cache time on the CDN, in seconds.
1912          */
1913         public function setCdnMaxage( $maxage ) {
1914                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1915         }
1916
1917         /**
1918          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1919          *
1920          * @param int $maxage Maximum cache time on the CDN, in seconds
1921          * @since 1.27
1922          */
1923         public function lowerCdnMaxage( $maxage ) {
1924                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1925                 $this->setCdnMaxage( $this->mCdnMaxage );
1926         }
1927
1928         /**
1929          * Use enableClientCache(false) to force it to send nocache headers
1930          *
1931          * @param bool $state
1932          *
1933          * @return bool
1934          */
1935         public function enableClientCache( $state ) {
1936                 return wfSetVar( $this->mEnableClientCache, $state );
1937         }
1938
1939         /**
1940          * Get the list of cookies that will influence on the cache
1941          *
1942          * @return array
1943          */
1944         function getCacheVaryCookies() {
1945                 static $cookies;
1946                 if ( $cookies === null ) {
1947                         $config = $this->getConfig();
1948                         $cookies = array_merge(
1949                                 SessionManager::singleton()->getVaryCookies(),
1950                                 [
1951                                         'forceHTTPS',
1952                                 ],
1953                                 $config->get( 'CacheVaryCookies' )
1954                         );
1955                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
1956                 }
1957                 return $cookies;
1958         }
1959
1960         /**
1961          * Check if the request has a cache-varying cookie header
1962          * If it does, it's very important that we don't allow public caching
1963          *
1964          * @return bool
1965          */
1966         function haveCacheVaryCookies() {
1967                 $request = $this->getRequest();
1968                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
1969                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
1970                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
1971                                 return true;
1972                         }
1973                 }
1974                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
1975                 return false;
1976         }
1977
1978         /**
1979          * Add an HTTP header that will influence on the cache
1980          *
1981          * @param string $header Header name
1982          * @param string[]|null $option Options for the Key header. See
1983          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
1984          * for the list of valid options.
1985          */
1986         public function addVaryHeader( $header, array $option = null ) {
1987                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
1988                         $this->mVaryHeader[$header] = [];
1989                 }
1990                 if ( !is_array( $option ) ) {
1991                         $option = [];
1992                 }
1993                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
1994         }
1995
1996         /**
1997          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
1998          * such as Accept-Encoding or Cookie
1999          *
2000          * @return string
2001          */
2002         public function getVaryHeader() {
2003                 // If we vary on cookies, let's make sure it's always included here too.
2004                 if ( $this->getCacheVaryCookies() ) {
2005                         $this->addVaryHeader( 'Cookie' );
2006                 }
2007
2008                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2009                         $this->addVaryHeader( $header, $options );
2010                 }
2011                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2012         }
2013
2014         /**
2015          * Get a complete Key header
2016          *
2017          * @return string
2018          */
2019         public function getKeyHeader() {
2020                 $cvCookies = $this->getCacheVaryCookies();
2021
2022                 $cookiesOption = [];
2023                 foreach ( $cvCookies as $cookieName ) {
2024                         $cookiesOption[] = 'param=' . $cookieName;
2025                 }
2026                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2027
2028                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2029                         $this->addVaryHeader( $header, $options );
2030                 }
2031
2032                 $headers = [];
2033                 foreach ( $this->mVaryHeader as $header => $option ) {
2034                         $newheader = $header;
2035                         if ( is_array( $option ) && count( $option ) > 0 ) {
2036                                 $newheader .= ';' . implode( ';', $option );
2037                         }
2038                         $headers[] = $newheader;
2039                 }
2040                 $key = 'Key: ' . implode( ',', $headers );
2041
2042                 return $key;
2043         }
2044
2045         /**
2046          * T23672: Add Accept-Language to Vary and Key headers
2047          * if there's no 'variant' parameter existed in GET.
2048          *
2049          * For example:
2050          *   /w/index.php?title=Main_page should always be served; but
2051          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2052          */
2053         function addAcceptLanguage() {
2054                 $title = $this->getTitle();
2055                 if ( !$title instanceof Title ) {
2056                         return;
2057                 }
2058
2059                 $lang = $title->getPageLanguage();
2060                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2061                         $variants = $lang->getVariants();
2062                         $aloption = [];
2063                         foreach ( $variants as $variant ) {
2064                                 if ( $variant === $lang->getCode() ) {
2065                                         continue;
2066                                 } else {
2067                                         $aloption[] = 'substr=' . $variant;
2068
2069                                         // IE and some other browsers use BCP 47 standards in
2070                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2071                                         // We should handle these too.
2072                                         $variantBCP47 = wfBCP47( $variant );
2073                                         if ( $variantBCP47 !== $variant ) {
2074                                                 $aloption[] = 'substr=' . $variantBCP47;
2075                                         }
2076                                 }
2077                         }
2078                         $this->addVaryHeader( 'Accept-Language', $aloption );
2079                 }
2080         }
2081
2082         /**
2083          * Set a flag which will cause an X-Frame-Options header appropriate for
2084          * edit pages to be sent. The header value is controlled by
2085          * $wgEditPageFrameOptions.
2086          *
2087          * This is the default for special pages. If you display a CSRF-protected
2088          * form on an ordinary view page, then you need to call this function.
2089          *
2090          * @param bool $enable
2091          */
2092         public function preventClickjacking( $enable = true ) {
2093                 $this->mPreventClickjacking = $enable;
2094         }
2095
2096         /**
2097          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2098          * This can be called from pages which do not contain any CSRF-protected
2099          * HTML form.
2100          */
2101         public function allowClickjacking() {
2102                 $this->mPreventClickjacking = false;
2103         }
2104
2105         /**
2106          * Get the prevent-clickjacking flag
2107          *
2108          * @since 1.24
2109          * @return bool
2110          */
2111         public function getPreventClickjacking() {
2112                 return $this->mPreventClickjacking;
2113         }
2114
2115         /**
2116          * Get the X-Frame-Options header value (without the name part), or false
2117          * if there isn't one. This is used by Skin to determine whether to enable
2118          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2119          *
2120          * @return string
2121          */
2122         public function getFrameOptions() {
2123                 $config = $this->getConfig();
2124                 if ( $config->get( 'BreakFrames' ) ) {
2125                         return 'DENY';
2126                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2127                         return $config->get( 'EditPageFrameOptions' );
2128                 }
2129                 return false;
2130         }
2131
2132         /**
2133          * Send cache control HTTP headers
2134          */
2135         public function sendCacheControl() {
2136                 $response = $this->getRequest()->response();
2137                 $config = $this->getConfig();
2138
2139                 $this->addVaryHeader( 'Cookie' );
2140                 $this->addAcceptLanguage();
2141
2142                 # don't serve compressed data to clients who can't handle it
2143                 # maintain different caches for logged-in users and non-logged in ones
2144                 $response->header( $this->getVaryHeader() );
2145
2146                 if ( $config->get( 'UseKeyHeader' ) ) {
2147                         $response->header( $this->getKeyHeader() );
2148                 }
2149
2150                 if ( $this->mEnableClientCache ) {
2151                         if (
2152                                 $config->get( 'UseSquid' ) &&
2153                                 !$response->hasCookies() &&
2154                                 !SessionManager::getGlobalSession()->isPersistent() &&
2155                                 !$this->isPrintable() &&
2156                                 $this->mCdnMaxage != 0 &&
2157                                 !$this->haveCacheVaryCookies()
2158                         ) {
2159                                 if ( $config->get( 'UseESI' ) ) {
2160                                         # We'll purge the proxy cache explicitly, but require end user agents
2161                                         # to revalidate against the proxy on each visit.
2162                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2163                                         wfDebug( __METHOD__ . ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2164                                         # start with a shorter timeout for initial testing
2165                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2166                                         $response->header( 'Surrogate-Control: max-age=' . $config->get( 'SquidMaxage' )
2167                                                 . '+' . $this->mCdnMaxage . ', content="ESI/1.0"' );
2168                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2169                                 } else {
2170                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2171                                         # to revalidate against the proxy on each visit.
2172                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2173                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2174                                         wfDebug( __METHOD__ . ": local proxy caching; {$this->mLastModified} **", 'private' );
2175                                         # start with a shorter timeout for initial testing
2176                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2177                                         $response->header( 'Cache-Control: s-maxage=' . $this->mCdnMaxage
2178                                                 . ', must-revalidate, max-age=0' );
2179                                 }
2180                         } else {
2181                                 # We do want clients to cache if they can, but they *must* check for updates
2182                                 # on revisiting the page.
2183                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2184                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2185                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2186                         }
2187                         if ( $this->mLastModified ) {
2188                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2189                         }
2190                 } else {
2191                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2192
2193                         # In general, the absence of a last modified header should be enough to prevent
2194                         # the client from using its cache. We send a few other things just to make sure.
2195                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2196                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2197                         $response->header( 'Pragma: no-cache' );
2198                 }
2199         }
2200
2201         /**
2202          * Finally, all the text has been munged and accumulated into
2203          * the object, let's actually output it:
2204          */
2205         public function output() {
2206                 if ( $this->mDoNothing ) {
2207                         return;
2208                 }
2209
2210                 $response = $this->getRequest()->response();
2211                 $config = $this->getConfig();
2212
2213                 if ( $this->mRedirect != '' ) {
2214                         # Standards require redirect URLs to be absolute
2215                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2216
2217                         $redirect = $this->mRedirect;
2218                         $code = $this->mRedirectCode;
2219
2220                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2221                                 if ( $code == '301' || $code == '303' ) {
2222                                         if ( !$config->get( 'DebugRedirects' ) ) {
2223                                                 $response->statusHeader( $code );
2224                                         }
2225                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2226                                 }
2227                                 if ( $config->get( 'VaryOnXFP' ) ) {
2228                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2229                                 }
2230                                 $this->sendCacheControl();
2231
2232                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2233                                 if ( $config->get( 'DebugRedirects' ) ) {
2234                                         $url = htmlspecialchars( $redirect );
2235                                         print "<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2236                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2237                                         print "</body>\n</html>\n";
2238                                 } else {
2239                                         $response->header( 'Location: ' . $redirect );
2240                                 }
2241                         }
2242
2243                         return;
2244                 } elseif ( $this->mStatusCode ) {
2245                         $response->statusHeader( $this->mStatusCode );
2246                 }
2247
2248                 # Buffer output; final headers may depend on later processing
2249                 ob_start();
2250
2251                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2252                 $response->header( 'Content-language: ' . $config->get( 'LanguageCode' ) );
2253
2254                 // Avoid Internet Explorer "compatibility view" in IE 8-10, so that
2255                 // jQuery etc. can work correctly.
2256                 $response->header( 'X-UA-Compatible: IE=Edge' );
2257
2258                 // Prevent framing, if requested
2259                 $frameOptions = $this->getFrameOptions();
2260                 if ( $frameOptions ) {
2261                         $response->header( "X-Frame-Options: $frameOptions" );
2262                 }
2263
2264                 if ( $this->mArticleBodyOnly ) {
2265                         echo $this->mBodytext;
2266                 } else {
2267                         $sk = $this->getSkin();
2268                         // add skin specific modules
2269                         $modules = $sk->getDefaultModules();
2270
2271                         // Enforce various default modules for all pages and all skins
2272                         $coreModules = [
2273                                 // Keep this list as small as possible
2274                                 'site',
2275                                 'mediawiki.page.startup',
2276                                 'mediawiki.user',
2277                         ];
2278
2279                         // Support for high-density display images if enabled
2280                         if ( $config->get( 'ResponsiveImages' ) ) {
2281                                 $coreModules[] = 'mediawiki.hidpi';
2282                         }
2283
2284                         $this->addModules( $coreModules );
2285                         foreach ( $modules as $group ) {
2286                                 $this->addModules( $group );
2287                         }
2288                         MWDebug::addModules( $this );
2289
2290                         // Hook that allows last minute changes to the output page, e.g.
2291                         // adding of CSS or Javascript by extensions.
2292                         Hooks::run( 'BeforePageDisplay', [ &$this, &$sk ] );
2293                         $this->getSkin()->setupSkinUserCss( $this );
2294
2295                         try {
2296                                 $sk->outputPage();
2297                         } catch ( Exception $e ) {
2298                                 ob_end_clean(); // bug T129657
2299                                 throw $e;
2300                         }
2301                 }
2302
2303                 try {
2304                         // This hook allows last minute changes to final overall output by modifying output buffer
2305                         Hooks::run( 'AfterFinalPageOutput', [ $this ] );
2306                 } catch ( Exception $e ) {
2307                         ob_end_clean(); // bug T129657
2308                         throw $e;
2309                 }
2310
2311                 $this->sendCacheControl();
2312
2313                 ob_end_flush();
2314
2315         }
2316
2317         /**
2318          * Prepare this object to display an error page; disable caching and
2319          * indexing, clear the current text and redirect, set the page's title
2320          * and optionally an custom HTML title (content of the "<title>" tag).
2321          *
2322          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2323          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2324          *                   optional, if not passed the "<title>" attribute will be
2325          *                   based on $pageTitle
2326          */
2327         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2328                 $this->setPageTitle( $pageTitle );
2329                 if ( $htmlTitle !== false ) {
2330                         $this->setHTMLTitle( $htmlTitle );
2331                 }
2332                 $this->setRobotPolicy( 'noindex,nofollow' );
2333                 $this->setArticleRelated( false );
2334                 $this->enableClientCache( false );
2335                 $this->mRedirect = '';
2336                 $this->clearSubtitle();
2337                 $this->clearHTML();
2338         }
2339
2340         /**
2341          * Output a standard error page
2342          *
2343          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2344          * showErrorPage( 'titlemsg', 'pagetextmsg', array( 'param1', 'param2' ) );
2345          * showErrorPage( 'titlemsg', $messageObject );
2346          * showErrorPage( $titleMessageObject, $messageObject );
2347          *
2348          * @param string|Message $title Message key (string) for page title, or a Message object
2349          * @param string|Message $msg Message key (string) for page text, or a Message object
2350          * @param array $params Message parameters; ignored if $msg is a Message object
2351          */
2352         public function showErrorPage( $title, $msg, $params = [] ) {
2353                 if ( !$title instanceof Message ) {
2354                         $title = $this->msg( $title );
2355                 }
2356
2357                 $this->prepareErrorPage( $title );
2358
2359                 if ( $msg instanceof Message ) {
2360                         if ( $params !== [] ) {
2361                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2362                                         . 'is discarded when the $msg argument is a Message object instead of '
2363                                         . 'a string.', E_USER_NOTICE );
2364                         }
2365                         $this->addHTML( $msg->parseAsBlock() );
2366                 } else {
2367                         $this->addWikiMsgArray( $msg, $params );
2368                 }
2369
2370                 $this->returnToMain();
2371         }
2372
2373         /**
2374          * Output a standard permission error page
2375          *
2376          * @param array $errors Error message keys
2377          * @param string $action Action that was denied or null if unknown
2378          */
2379         public function showPermissionsErrorPage( array $errors, $action = null ) {
2380                 // For some action (read, edit, create and upload), display a "login to do this action"
2381                 // error if all of the following conditions are met:
2382                 // 1. the user is not logged in
2383                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2384                 // 3. the error can be avoided simply by logging in
2385                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2386                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2387                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2388                         && ( User::groupHasPermission( 'user', $action )
2389                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2390                 ) {
2391                         $displayReturnto = null;
2392
2393                         # Due to bug 32276, if a user does not have read permissions,
2394                         # $this->getTitle() will just give Special:Badtitle, which is
2395                         # not especially useful as a returnto parameter. Use the title
2396                         # from the request instead, if there was one.
2397                         $request = $this->getRequest();
2398                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2399                         if ( $action == 'edit' ) {
2400                                 $msg = 'whitelistedittext';
2401                                 $displayReturnto = $returnto;
2402                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2403                                 $msg = 'nocreatetext';
2404                         } elseif ( $action == 'upload' ) {
2405                                 $msg = 'uploadnologintext';
2406                         } else { # Read
2407                                 $msg = 'loginreqpagetext';
2408                                 $displayReturnto = Title::newMainPage();
2409                         }
2410
2411                         $query = [];
2412
2413                         if ( $returnto ) {
2414                                 $query['returnto'] = $returnto->getPrefixedText();
2415
2416                                 if ( !$request->wasPosted() ) {
2417                                         $returntoquery = $request->getValues();
2418                                         unset( $returntoquery['title'] );
2419                                         unset( $returntoquery['returnto'] );
2420                                         unset( $returntoquery['returntoquery'] );
2421                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2422                                 }
2423                         }
2424                         $loginLink = Linker::linkKnown(
2425                                 SpecialPage::getTitleFor( 'Userlogin' ),
2426                                 $this->msg( 'loginreqlink' )->escaped(),
2427                                 [],
2428                                 $query
2429                         );
2430
2431                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2432                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2433
2434                         # Don't return to a page the user can't read otherwise
2435                         # we'll end up in a pointless loop
2436                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2437                                 $this->returnToMain( null, $displayReturnto );
2438                         }
2439                 } else {
2440                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2441                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2442                 }
2443         }
2444
2445         /**
2446          * Display an error page indicating that a given version of MediaWiki is
2447          * required to use it
2448          *
2449          * @param mixed $version The version of MediaWiki needed to use the page
2450          */
2451         public function versionRequired( $version ) {
2452                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2453
2454                 $this->addWikiMsg( 'versionrequiredtext', $version );
2455                 $this->returnToMain();
2456         }
2457
2458         /**
2459          * Format a list of error messages
2460          *
2461          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2462          * @param string $action Action that was denied or null if unknown
2463          * @return string The wikitext error-messages, formatted into a list.
2464          */
2465         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2466                 if ( $action == null ) {
2467                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2468                 } else {
2469                         $action_desc = $this->msg( "action-$action" )->plain();
2470                         $text = $this->msg(
2471                                 'permissionserrorstext-withaction',
2472                                 count( $errors ),
2473                                 $action_desc
2474                         )->plain() . "\n\n";
2475                 }
2476
2477                 if ( count( $errors ) > 1 ) {
2478                         $text .= '<ul class="permissions-errors">' . "\n";
2479
2480                         foreach ( $errors as $error ) {
2481                                 $text .= '<li>';
2482                                 $text .= call_user_func_array( [ $this, 'msg' ], $error )->plain();
2483                                 $text .= "</li>\n";
2484                         }
2485                         $text .= '</ul>';
2486                 } else {
2487                         $text .= "<div class=\"permissions-errors\">\n" .
2488                                         call_user_func_array( [ $this, 'msg' ], reset( $errors ) )->plain() .
2489                                         "\n</div>";
2490                 }
2491
2492                 return $text;
2493         }
2494
2495         /**
2496          * Display a page stating that the Wiki is in read-only mode.
2497          * Should only be called after wfReadOnly() has returned true.
2498          *
2499          * Historically, this function was used to show the source of the page that the user
2500          * was trying to edit and _also_ permissions error messages. The relevant code was
2501          * moved into EditPage in 1.19 (r102024 / d83c2a431c2a) and removed here in 1.25.
2502          *
2503          * @deprecated since 1.25; throw the exception directly
2504          * @throws ReadOnlyError
2505          */
2506         public function readOnlyPage() {
2507                 if ( func_num_args() > 0 ) {
2508                         throw new MWException( __METHOD__ . ' no longer accepts arguments since 1.25.' );
2509                 }
2510
2511                 throw new ReadOnlyError;
2512         }
2513
2514         /**
2515          * Turn off regular page output and return an error response
2516          * for when rate limiting has triggered.
2517          *
2518          * @deprecated since 1.25; throw the exception directly
2519          */
2520         public function rateLimited() {
2521                 wfDeprecated( __METHOD__, '1.25' );
2522                 throw new ThrottledError;
2523         }
2524
2525         /**
2526          * Show a warning about slave lag
2527          *
2528          * If the lag is higher than $wgSlaveLagCritical seconds,
2529          * then the warning is a bit more obvious. If the lag is
2530          * lower than $wgSlaveLagWarning, then no warning is shown.
2531          *
2532          * @param int $lag Slave lag
2533          */
2534         public function showLagWarning( $lag ) {
2535                 $config = $this->getConfig();
2536                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2537                         $message = $lag < $config->get( 'SlaveLagCritical' )
2538                                 ? 'lag-warn-normal'
2539                                 : 'lag-warn-high';
2540                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2541                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2542                 }
2543         }
2544
2545         public function showFatalError( $message ) {
2546                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2547
2548                 $this->addHTML( $message );
2549         }
2550
2551         public function showUnexpectedValueError( $name, $val ) {
2552                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2553         }
2554
2555         public function showFileCopyError( $old, $new ) {
2556                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2557         }
2558
2559         public function showFileRenameError( $old, $new ) {
2560                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2561         }
2562
2563         public function showFileDeleteError( $name ) {
2564                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2565         }
2566
2567         public function showFileNotFoundError( $name ) {
2568                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2569         }
2570
2571         /**
2572          * Add a "return to" link pointing to a specified title
2573          *
2574          * @param Title $title Title to link
2575          * @param array $query Query string parameters
2576          * @param string $text Text of the link (input is not escaped)
2577          * @param array $options Options array to pass to Linker
2578          */
2579         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2580                 $link = $this->msg( 'returnto' )->rawParams(
2581                         Linker::link( $title, $text, [], $query, $options ) )->escaped();
2582                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2583         }
2584
2585         /**
2586          * Add a "return to" link pointing to a specified title,
2587          * or the title indicated in the request, or else the main page
2588          *
2589          * @param mixed $unused
2590          * @param Title|string $returnto Title or String to return to
2591          * @param string $returntoquery Query string for the return to link
2592          */
2593         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2594                 if ( $returnto == null ) {
2595                         $returnto = $this->getRequest()->getText( 'returnto' );
2596                 }
2597
2598                 if ( $returntoquery == null ) {
2599                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2600                 }
2601
2602                 if ( $returnto === '' ) {
2603                         $returnto = Title::newMainPage();
2604                 }
2605
2606                 if ( is_object( $returnto ) ) {
2607                         $titleObj = $returnto;
2608                 } else {
2609                         $titleObj = Title::newFromText( $returnto );
2610                 }
2611                 if ( !is_object( $titleObj ) ) {
2612                         $titleObj = Title::newMainPage();
2613                 }
2614
2615                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2616         }
2617
2618         private function getRlClientContext() {
2619                 if ( !$this->rlClientContext ) {
2620                         $query = ResourceLoader::makeLoaderQuery(
2621                                 [], // modules; not relevant
2622                                 $this->getLanguage()->getCode(),
2623                                 $this->getSkin()->getSkinName(),
2624                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2625                                 null, // version; not relevant
2626                                 ResourceLoader::inDebugMode(),
2627                                 null, // only; not relevant
2628                                 $this->isPrintable(),
2629                                 $this->getRequest()->getBool( 'handheld' )
2630                         );
2631                         $this->rlClientContext = new ResourceLoaderContext(
2632                                 $this->getResourceLoader(),
2633                                 new FauxRequest( $query )
2634                         );
2635                 }
2636                 return $this->rlClientContext;
2637         }
2638
2639         /**
2640          * Call this to freeze the module queue and JS config and create a formatter.
2641          *
2642          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2643          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2644          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2645          * the module filters retroactively. Skins and extension hooks may also add modules until very
2646          * late in the request lifecycle.
2647          *
2648          * @return ResourceLoaderClientHtml
2649          */
2650         public function getRlClient() {
2651                 if ( !$this->rlClient ) {
2652                         $context = $this->getRlClientContext();
2653                         $userModule = $this->getResourceLoader()->getModule( 'user' );
2654                         // Manually handled by getBottomScripts()
2655                         $userState = $userModule->isKnownEmpty( $context ) && !$this->isUserModulePreview()
2656                                 ? 'ready'
2657                                 : 'loading';
2658                         $this->rlUserModuleState = $userState;
2659
2660                         $this->addModules( [
2661                                 'user.options',
2662                                 'user.tokens',
2663                         ] );
2664                         $rlClient = new ResourceLoaderClientHtml( $context );
2665                         $rlClient->setConfig( $this->getJSVars() );
2666                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2667                         $rlClient->setModuleStyles( $this->getModuleStyles( /*filter*/ true ) );
2668                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2669                         $rlClient->setExemptStates( [
2670                                 'user' => $userState,
2671                                 // Manually handled by buildExemptModules() and getBottomScripts()
2672                                 'site.styles' => 'ready',
2673                                 'noscript' => 'ready',
2674                                 'user.cssprefs' => 'ready',
2675                                 'user.styles' => 'ready',
2676                         ] );
2677                         $this->rlClient = $rlClient;
2678                 }
2679                 return $this->rlClient;
2680         }
2681
2682         /**
2683          * @param Skin $sk The given Skin
2684          * @param bool $includeStyle Unused
2685          * @return string The doctype, opening "<html>", and head element.
2686          */
2687         public function headElement( Skin $sk, $includeStyle = true ) {
2688                 global $wgContLang;
2689
2690                 $userdir = $this->getLanguage()->getDir();
2691                 $sitedir = $wgContLang->getDir();
2692
2693                 $pieces = [];
2694                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2695                         $this->getRlClient()->getDocumentAttributes(),
2696                         $sk->getHtmlElementAttributes()
2697                 ) );
2698                 $pieces[] = Html::openElement( 'head' );
2699
2700                 if ( $this->getHTMLTitle() == '' ) {
2701                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2702                 }
2703
2704                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2705                         // Add <meta charset="UTF-8">
2706                         // This should be before <title> since it defines the charset used by
2707                         // text including the text inside <title>.
2708                         // The spec recommends defining XHTML5's charset using the XML declaration
2709                         // instead of meta.
2710                         // Our XML declaration is output by Html::htmlHeader.
2711                         // http://www.whatwg.org/html/semantics.html#attr-meta-http-equiv-content-type
2712                         // http://www.whatwg.org/html/semantics.html#charset
2713                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2714                 }
2715
2716                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2717                 $pieces[] = $this->getRlClient()->getHeadHtml();
2718                 $pieces[] = $this->buildExemptModules();
2719                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2720                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2721                 $pieces[] = Html::closeElement( 'head' );
2722
2723                 $bodyClasses = [];
2724                 $bodyClasses[] = 'mediawiki';
2725
2726                 # Classes for LTR/RTL directionality support
2727                 $bodyClasses[] = $userdir;
2728                 $bodyClasses[] = "sitedir-$sitedir";
2729
2730                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2731                         # A <body> class is probably not the best way to do this . . .
2732                         $bodyClasses[] = 'capitalize-all-nouns';
2733                 }
2734
2735                 // Parser feature migration class
2736                 // The idea is that this will eventually be removed, after the wikitext
2737                 // which requires it is cleaned up.
2738                 $bodyClasses[] = 'mw-hide-empty-elt';
2739
2740                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2741                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2742                 $bodyClasses[] =
2743                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2744
2745                 $bodyAttrs = [];
2746                 // While the implode() is not strictly needed, it's used for backwards compatibility
2747                 // (this used to be built as a string and hooks likely still expect that).
2748                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2749
2750                 // Allow skins and extensions to add body attributes they need
2751                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2752                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2753
2754                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2755
2756                 return self::combineWrappedStrings( $pieces );
2757         }
2758
2759         /**
2760          * Get a ResourceLoader object associated with this OutputPage
2761          *
2762          * @return ResourceLoader
2763          */
2764         public function getResourceLoader() {
2765                 if ( is_null( $this->mResourceLoader ) ) {
2766                         $this->mResourceLoader = new ResourceLoader(
2767                                 $this->getConfig(),
2768                                 LoggerFactory::getInstance( 'resourceloader' )
2769                         );
2770                 }
2771                 return $this->mResourceLoader;
2772         }
2773
2774         /**
2775          * Explicily load or embed modules on a page.
2776          *
2777          * @param array|string $modules One or more module names
2778          * @param string $only ResourceLoaderModule TYPE_ class constant
2779          * @param array $extraQuery [optional] Array with extra query parameters for the request
2780          * @return string|WrappedStringList HTML
2781          */
2782         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2783                 return ResourceLoaderClientHtml::makeLoad(
2784                         $this->getRlClientContext(),
2785                         (array)$modules,
2786                         $only,
2787                         $extraQuery
2788                 );
2789         }
2790
2791         /**
2792          * Combine WrappedString chunks and filter out empty ones
2793          *
2794          * @param array $chunks
2795          * @return string|WrappedStringList HTML
2796          */
2797         protected static function combineWrappedStrings( array $chunks ) {
2798                 // Filter out empty values
2799                 $chunks = array_filter( $chunks, 'strlen' );
2800                 return WrappedString::join( "\n", $chunks );
2801         }
2802
2803         /** @return bool */
2804         private function isUserModulePreview() {
2805                 return $this->getConfig()->get( 'AllowUserJs' )
2806                         && $this->getUser()->isLoggedIn()
2807                         && $this->getTitle()
2808                         && $this->getTitle()->isJsSubpage()
2809                         && $this->userCanPreview();
2810         }
2811
2812         /**
2813          * JS stuff to put at the bottom of the `<body>`. These are modules with position 'bottom',
2814          * legacy scripts ($this->mScripts), and user JS.
2815          *
2816          * @return string|WrappedStringList HTML
2817          */
2818         public function getBottomScripts() {
2819                 $chunks = [];
2820                 $chunks[] = $this->getRlClient()->getBodyHtml();
2821
2822                 // Legacy non-ResourceLoader scripts
2823                 $chunks[] = $this->mScripts;
2824
2825                 // Exempt 'user' module
2826                 // - May need excludepages for live preview. (T28283)
2827                 // - Must use TYPE_COMBINED so its response is handled by mw.loader.implement() which
2828                 //   ensures execution is scheduled after the "site" module.
2829                 // - Don't load if module state is already resolved as "ready".
2830                 if ( $this->rlUserModuleState === 'loading' ) {
2831                         if ( $this->isUserModulePreview() ) {
2832                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED,
2833                                         [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
2834                                 );
2835                                 $chunks[] = ResourceLoader::makeInlineScript(
2836                                         Xml::encodeJsCall( 'mw.loader.using', [
2837                                                 [ 'user', 'site' ],
2838                                                 new XmlJsCode(
2839                                                         'function () {'
2840                                                                 . Xml::encodeJsCall( '$.globalEval', [
2841                                                                         $this->getRequest()->getText( 'wpTextbox1' )
2842                                                                 ] )
2843                                                                 . '}'
2844                                                 )
2845                                         ] )
2846                                 );
2847                                 // FIXME: If the user is previewing, say, ./vector.js, his ./common.js will be loaded
2848                                 // asynchronously and may arrive *after* the inline script here. So the previewed code
2849                                 // may execute before ./common.js runs. Normally, ./common.js runs before ./vector.js.
2850                                 // Similarly, when previewing ./common.js and the user module does arrive first,
2851                                 // it will arrive without common.js and the inline script runs after.
2852                                 // Thus running common after the excluded subpage.
2853                         } else {
2854                                 // Load normally
2855                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED );
2856                         }
2857                 }
2858
2859                 $chunks[] = ResourceLoader::makeInlineScript(
2860                         ResourceLoader::makeConfigSetScript(
2861                                 [ 'wgPageParseReport' => $this->limitReportData ],
2862                                 true
2863                         )
2864                 );
2865
2866                 return self::combineWrappedStrings( $chunks );
2867         }
2868
2869         /**
2870          * Get the javascript config vars to include on this page
2871          *
2872          * @return array Array of javascript config vars
2873          * @since 1.23
2874          */
2875         public function getJsConfigVars() {
2876                 return $this->mJsConfigVars;
2877         }
2878
2879         /**
2880          * Add one or more variables to be set in mw.config in JavaScript
2881          *
2882          * @param string|array $keys Key or array of key/value pairs
2883          * @param mixed $value [optional] Value of the configuration variable
2884          */
2885         public function addJsConfigVars( $keys, $value = null ) {
2886                 if ( is_array( $keys ) ) {
2887                         foreach ( $keys as $key => $value ) {
2888                                 $this->mJsConfigVars[$key] = $value;
2889                         }
2890                         return;
2891                 }
2892
2893                 $this->mJsConfigVars[$keys] = $value;
2894         }
2895
2896         /**
2897          * Get an array containing the variables to be set in mw.config in JavaScript.
2898          *
2899          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
2900          * - in other words, page-independent/site-wide variables (without state).
2901          * You will only be adding bloat to the html page and causing page caches to
2902          * have to be purged on configuration changes.
2903          * @return array
2904          */
2905         public function getJSVars() {
2906                 global $wgContLang;
2907
2908                 $curRevisionId = 0;
2909                 $articleId = 0;
2910                 $canonicalSpecialPageName = false; # bug 21115
2911
2912                 $title = $this->getTitle();
2913                 $ns = $title->getNamespace();
2914                 $canonicalNamespace = MWNamespace::exists( $ns )
2915                         ? MWNamespace::getCanonicalName( $ns )
2916                         : $title->getNsText();
2917
2918                 $sk = $this->getSkin();
2919                 // Get the relevant title so that AJAX features can use the correct page name
2920                 // when making API requests from certain special pages (bug 34972).
2921                 $relevantTitle = $sk->getRelevantTitle();
2922                 $relevantUser = $sk->getRelevantUser();
2923
2924                 if ( $ns == NS_SPECIAL ) {
2925                         list( $canonicalSpecialPageName, /*...*/ ) =
2926                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
2927                 } elseif ( $this->canUseWikiPage() ) {
2928                         $wikiPage = $this->getWikiPage();
2929                         $curRevisionId = $wikiPage->getLatest();
2930                         $articleId = $wikiPage->getId();
2931                 }
2932
2933                 $lang = $title->getPageViewLanguage();
2934
2935                 // Pre-process information
2936                 $separatorTransTable = $lang->separatorTransformTable();
2937                 $separatorTransTable = $separatorTransTable ? $separatorTransTable : [];
2938                 $compactSeparatorTransTable = [
2939                         implode( "\t", array_keys( $separatorTransTable ) ),
2940                         implode( "\t", $separatorTransTable ),
2941                 ];
2942                 $digitTransTable = $lang->digitTransformTable();
2943                 $digitTransTable = $digitTransTable ? $digitTransTable : [];
2944                 $compactDigitTransTable = [
2945                         implode( "\t", array_keys( $digitTransTable ) ),
2946                         implode( "\t", $digitTransTable ),
2947                 ];
2948
2949                 $user = $this->getUser();
2950
2951                 $vars = [
2952                         'wgCanonicalNamespace' => $canonicalNamespace,
2953                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
2954                         'wgNamespaceNumber' => $title->getNamespace(),
2955                         'wgPageName' => $title->getPrefixedDBkey(),
2956                         'wgTitle' => $title->getText(),
2957                         'wgCurRevisionId' => $curRevisionId,
2958                         'wgRevisionId' => (int)$this->getRevisionId(),
2959                         'wgArticleId' => $articleId,
2960                         'wgIsArticle' => $this->isArticle(),
2961                         'wgIsRedirect' => $title->isRedirect(),
2962                         'wgAction' => Action::getActionName( $this->getContext() ),
2963                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
2964                         'wgUserGroups' => $user->getEffectiveGroups(),
2965                         'wgCategories' => $this->getCategories(),
2966                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
2967                         'wgPageContentLanguage' => $lang->getCode(),
2968                         'wgPageContentModel' => $title->getContentModel(),
2969                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
2970                         'wgDigitTransformTable' => $compactDigitTransTable,
2971                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
2972                         'wgMonthNames' => $lang->getMonthNamesArray(),
2973                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
2974                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
2975                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
2976                         'wgRequestId' => WebRequest::getRequestId(),
2977                 ];
2978
2979                 if ( $user->isLoggedIn() ) {
2980                         $vars['wgUserId'] = $user->getId();
2981                         $vars['wgUserEditCount'] = $user->getEditCount();
2982                         $userReg = wfTimestampOrNull( TS_UNIX, $user->getRegistration() );
2983                         $vars['wgUserRegistration'] = $userReg !== null ? ( $userReg * 1000 ) : null;
2984                         // Get the revision ID of the oldest new message on the user's talk
2985                         // page. This can be used for constructing new message alerts on
2986                         // the client side.
2987                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
2988                 }
2989
2990                 if ( $wgContLang->hasVariants() ) {
2991                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
2992                 }
2993                 // Same test as SkinTemplate
2994                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
2995                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
2996
2997                 foreach ( $title->getRestrictionTypes() as $type ) {
2998                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
2999                 }
3000
3001                 if ( $title->isMainPage() ) {
3002                         $vars['wgIsMainPage'] = true;
3003                 }
3004
3005                 if ( $this->mRedirectedFrom ) {
3006                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3007                 }
3008
3009                 if ( $relevantUser ) {
3010                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3011                 }
3012
3013                 // Allow extensions to add their custom variables to the mw.config map.
3014                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3015                 // page-dependant but site-wide (without state).
3016                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3017                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3018
3019                 // Merge in variables from addJsConfigVars last
3020                 return array_merge( $vars, $this->getJsConfigVars() );
3021         }
3022
3023         /**
3024          * To make it harder for someone to slip a user a fake
3025          * user-JavaScript or user-CSS preview, a random token
3026          * is associated with the login session. If it's not
3027          * passed back with the preview request, we won't render
3028          * the code.
3029          *
3030          * @return bool
3031          */
3032         public function userCanPreview() {
3033                 $request = $this->getRequest();
3034                 if (
3035                         $request->getVal( 'action' ) !== 'submit' ||
3036                         !$request->getCheck( 'wpPreview' ) ||
3037                         !$request->wasPosted()
3038                 ) {
3039                         return false;
3040                 }
3041
3042                 $user = $this->getUser();
3043                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3044                         return false;
3045                 }
3046
3047                 $title = $this->getTitle();
3048                 if ( !$title->isJsSubpage() && !$title->isCssSubpage() ) {
3049                         return false;
3050                 }
3051                 if ( !$title->isSubpageOf( $user->getUserPage() ) ) {
3052                         // Don't execute another user's CSS or JS on preview (T85855)
3053                         return false;
3054                 }
3055
3056                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3057                 if ( count( $errors ) !== 0 ) {
3058                         return false;
3059                 }
3060
3061                 return true;
3062         }
3063
3064         /**
3065          * @return array Array in format "link name or number => 'link html'".
3066          */
3067         public function getHeadLinksArray() {
3068                 global $wgVersion;
3069
3070                 $tags = [];
3071                 $config = $this->getConfig();
3072
3073                 $canonicalUrl = $this->mCanonicalUrl;
3074
3075                 $tags['meta-generator'] = Html::element( 'meta', [
3076                         'name' => 'generator',
3077                         'content' => "MediaWiki $wgVersion",
3078                 ] );
3079
3080                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3081                         $tags['meta-referrer'] = Html::element( 'meta', [
3082                                 'name' => 'referrer',
3083                                 'content' => $config->get( 'ReferrerPolicy' )
3084                         ] );
3085                 }
3086
3087                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3088                 if ( $p !== 'index,follow' ) {
3089                         // http://www.robotstxt.org/wc/meta-user.html
3090                         // Only show if it's different from the default robots policy
3091                         $tags['meta-robots'] = Html::element( 'meta', [
3092                                 'name' => 'robots',
3093                                 'content' => $p,
3094                         ] );
3095                 }
3096
3097                 foreach ( $this->mMetatags as $tag ) {
3098                         if ( 0 == strcasecmp( 'http:', substr( $tag[0], 0, 5 ) ) ) {
3099                                 $a = 'http-equiv';
3100                                 $tag[0] = substr( $tag[0], 5 );
3101                         } else {
3102                                 $a = 'name';
3103                         }
3104                         $tagName = "meta-{$tag[0]}";
3105                         if ( isset( $tags[$tagName] ) ) {
3106                                 $tagName .= $tag[1];
3107                         }
3108                         $tags[$tagName] = Html::element( 'meta',
3109                                 [
3110                                         $a => $tag[0],
3111                                         'content' => $tag[1]
3112                                 ]
3113                         );
3114                 }
3115
3116                 foreach ( $this->mLinktags as $tag ) {
3117                         $tags[] = Html::element( 'link', $tag );
3118                 }
3119
3120                 # Universal edit button
3121                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3122                         $user = $this->getUser();
3123                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3124                                 && ( $this->getTitle()->exists() ||
3125                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3126                         ) {
3127                                 // Original UniversalEditButton
3128                                 $msg = $this->msg( 'edit' )->text();
3129                                 $tags['universal-edit-button'] = Html::element( 'link', [
3130                                         'rel' => 'alternate',
3131                                         'type' => 'application/x-wiki',
3132                                         'title' => $msg,
3133                                         'href' => $this->getTitle()->getEditURL(),
3134                                 ] );
3135                                 // Alternate edit link
3136                                 $tags['alternative-edit'] = Html::element( 'link', [
3137                                         'rel' => 'edit',
3138                                         'title' => $msg,
3139                                         'href' => $this->getTitle()->getEditURL(),
3140                                 ] );
3141                         }
3142                 }
3143
3144                 # Generally the order of the favicon and apple-touch-icon links
3145                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3146                 # uses whichever one appears later in the HTML source. Make sure
3147                 # apple-touch-icon is specified first to avoid this.
3148                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3149                         $tags['apple-touch-icon'] = Html::element( 'link', [
3150                                 'rel' => 'apple-touch-icon',
3151                                 'href' => $config->get( 'AppleTouchIcon' )
3152                         ] );
3153                 }
3154
3155                 if ( $config->get( 'Favicon' ) !== false ) {
3156                         $tags['favicon'] = Html::element( 'link', [
3157                                 'rel' => 'shortcut icon',
3158                                 'href' => $config->get( 'Favicon' )
3159                         ] );
3160                 }
3161
3162                 # OpenSearch description link
3163                 $tags['opensearch'] = Html::element( 'link', [
3164                         'rel' => 'search',
3165                         'type' => 'application/opensearchdescription+xml',
3166                         'href' => wfScript( 'opensearch_desc' ),
3167                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3168                 ] );
3169
3170                 if ( $config->get( 'EnableAPI' ) ) {
3171                         # Real Simple Discovery link, provides auto-discovery information
3172                         # for the MediaWiki API (and potentially additional custom API
3173                         # support such as WordPress or Twitter-compatible APIs for a
3174                         # blogging extension, etc)
3175                         $tags['rsd'] = Html::element( 'link', [
3176                                 'rel' => 'EditURI',
3177                                 'type' => 'application/rsd+xml',
3178                                 // Output a protocol-relative URL here if $wgServer is protocol-relative.
3179                                 // Whether RSD accepts relative or protocol-relative URLs is completely
3180                                 // undocumented, though.
3181                                 'href' => wfExpandUrl( wfAppendQuery(
3182                                         wfScript( 'api' ),
3183                                         [ 'action' => 'rsd' ] ),
3184                                         PROTO_RELATIVE
3185                                 ),
3186                         ] );
3187                 }
3188
3189                 # Language variants
3190                 if ( !$config->get( 'DisableLangConversion' ) ) {
3191                         $lang = $this->getTitle()->getPageLanguage();
3192                         if ( $lang->hasVariants() ) {
3193                                 $variants = $lang->getVariants();
3194                                 foreach ( $variants as $variant ) {
3195                                         $tags["variant-$variant"] = Html::element( 'link', [
3196                                                 'rel' => 'alternate',
3197                                                 'hreflang' => wfBCP47( $variant ),
3198                                                 'href' => $this->getTitle()->getLocalURL(
3199                                                         [ 'variant' => $variant ] )
3200                                                 ]
3201                                         );
3202                                 }
3203                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3204                                 $tags["variant-x-default"] = Html::element( 'link', [
3205                                         'rel' => 'alternate',
3206                                         'hreflang' => 'x-default',
3207                                         'href' => $this->getTitle()->getLocalURL() ] );
3208                         }
3209                 }
3210
3211                 # Copyright
3212                 if ( $this->copyrightUrl !== null ) {
3213                         $copyright = $this->copyrightUrl;
3214                 } else {
3215                         $copyright = '';
3216                         if ( $config->get( 'RightsPage' ) ) {
3217                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3218
3219                                 if ( $copy ) {
3220                                         $copyright = $copy->getLocalURL();
3221                                 }
3222                         }
3223
3224                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3225                                 $copyright = $config->get( 'RightsUrl' );
3226                         }
3227                 }
3228
3229                 if ( $copyright ) {
3230                         $tags['copyright'] = Html::element( 'link', [
3231                                 'rel' => 'copyright',
3232                                 'href' => $copyright ]
3233                         );
3234                 }
3235
3236                 # Feeds
3237                 if ( $config->get( 'Feed' ) ) {
3238                         $feedLinks = [];
3239
3240                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3241                                 # Use the page name for the title.  In principle, this could
3242                                 # lead to issues with having the same name for different feeds
3243                                 # corresponding to the same page, but we can't avoid that at
3244                                 # this low a level.
3245
3246                                 $feedLinks[] = $this->feedLink(
3247                                         $format,
3248                                         $link,
3249                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3250                                         $this->msg(
3251                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3252                                         )->text()
3253                                 );
3254                         }
3255
3256                         # Recent changes feed should appear on every page (except recentchanges,
3257                         # that would be redundant). Put it after the per-page feed to avoid
3258                         # changing existing behavior. It's still available, probably via a
3259                         # menu in your browser. Some sites might have a different feed they'd
3260                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3261                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3262                         # If so, use it instead.
3263                         $sitename = $config->get( 'Sitename' );
3264                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3265                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3266                                         // Note, this->feedLink escapes the url.
3267                                         $feedLinks[] = $this->feedLink(
3268                                                 $type,
3269                                                 $feedUrl,
3270                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3271                                         );
3272                                 }
3273                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3274                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3275                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3276                                         $feedLinks[] = $this->feedLink(
3277                                                 $format,
3278                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3279                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3280                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3281                                         );
3282                                 }
3283                         }
3284
3285                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3286                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3287                         # use OutputPage::addFeedLink() instead.
3288                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3289
3290                         $tags += $feedLinks;
3291                 }
3292
3293                 # Canonical URL
3294                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3295                         if ( $canonicalUrl !== false ) {
3296                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3297                         } else {
3298                                 if ( $this->isArticleRelated() ) {
3299                                         // This affects all requests where "setArticleRelated" is true. This is
3300                                         // typically all requests that show content (query title, curid, oldid, diff),
3301                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3302                                         // It does not apply to File pages and Special pages.
3303                                         // 'history' and 'info' actions address page metadata rather than the page
3304                                         // content itself, so they may not be canonicalized to the view page url.
3305                                         // TODO: this ought to be better encapsulated in the Action class.
3306                                         $action = Action::getActionName( $this->getContext() );
3307                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3308                                                 $query = "action={$action}";
3309                                         } else {
3310                                                 $query = '';
3311                                         }
3312                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3313                                 } else {
3314                                         $reqUrl = $this->getRequest()->getRequestURL();
3315                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3316                                 }
3317                         }
3318                 }
3319                 if ( $canonicalUrl !== false ) {
3320                         $tags[] = Html::element( 'link', [
3321                                 'rel' => 'canonical',
3322                                 'href' => $canonicalUrl
3323                         ] );
3324                 }
3325
3326                 return $tags;
3327         }
3328
3329         /**
3330          * @return string HTML tag links to be put in the header.
3331          * @deprecated since 1.24 Use OutputPage::headElement or if you have to,
3332          *   OutputPage::getHeadLinksArray directly.
3333          */
3334         public function getHeadLinks() {
3335                 wfDeprecated( __METHOD__, '1.24' );
3336                 return implode( "\n", $this->getHeadLinksArray() );
3337         }
3338
3339         /**
3340          * Generate a "<link rel/>" for a feed.
3341          *
3342          * @param string $type Feed type
3343          * @param string $url URL to the feed
3344          * @param string $text Value of the "title" attribute
3345          * @return string HTML fragment
3346          */
3347         private function feedLink( $type, $url, $text ) {
3348                 return Html::element( 'link', [
3349                         'rel' => 'alternate',
3350                         'type' => "application/$type+xml",
3351                         'title' => $text,
3352                         'href' => $url ]
3353                 );
3354         }
3355
3356         /**
3357          * Add a local or specified stylesheet, with the given media options.
3358          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3359          *
3360          * @param string $style URL to the file
3361          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3362          * @param string $condition For IE conditional comments, specifying an IE version
3363          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3364          */
3365         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3366                 $options = [];
3367                 if ( $media ) {
3368                         $options['media'] = $media;
3369                 }
3370                 if ( $condition ) {
3371                         $options['condition'] = $condition;
3372                 }
3373                 if ( $dir ) {
3374                         $options['dir'] = $dir;
3375                 }
3376                 $this->styles[$style] = $options;
3377         }
3378
3379         /**
3380          * Adds inline CSS styles
3381          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3382          *
3383          * @param mixed $style_css Inline CSS
3384          * @param string $flip Set to 'flip' to flip the CSS if needed
3385          */
3386         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3387                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3388                         # If wanted, and the interface is right-to-left, flip the CSS
3389                         $style_css = CSSJanus::transform( $style_css, true, false );
3390                 }
3391                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3392         }
3393
3394         /**
3395          * Build exempt modules and legacy non-ResourceLoader styles.
3396          *
3397          * @return string|WrappedStringList HTML
3398          */
3399         protected function buildExemptModules() {
3400                 global $wgContLang;
3401
3402                 $resourceLoader = $this->getResourceLoader();
3403                 $chunks = [];
3404                 // Things that should be appended after the other link and style chunks
3405                 $append = [];
3406                 $moduleStyles = [
3407                         'site.styles',
3408                         'noscript'
3409                 ];
3410
3411                 // Exempt 'user' styles module.
3412                 // - May need excludepages for live preview.
3413                 // - Position after ResourceLoaderDynamicStyles marker
3414                 if ( $this->getConfig()->get( 'AllowUserCss' ) && $this->getTitle()->isCssSubpage()
3415                         && $this->userCanPreview()
3416                 ) {
3417                         $append[] = $this->makeResourceLoaderLink(
3418                                 'user.styles',
3419                                 ResourceLoaderModule::TYPE_STYLES,
3420                                 [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3421                         );
3422
3423                         // Load the previewed CSS. Janus it if needed.
3424                         // User-supplied CSS is assumed to in the wiki's content language.
3425                         $previewedCSS = $this->getRequest()->getText( 'wpTextbox1' );
3426                         if ( $this->getLanguage()->getDir() !== $wgContLang->getDir() ) {
3427                                 $previewedCSS = CSSJanus::transform( $previewedCSS, true, false );
3428                         }
3429                         $append[] = Html::inlineStyle( $previewedCSS );
3430                 } else {
3431                         $module = $this->getResourceLoader()->getModule( 'user.styles' );
3432                         if ( !$module->isKnownEmpty( $this->getRlClientContext() ) ) {
3433                                 // Load styles normally
3434                                 $moduleStyles[] = 'user.styles';
3435                         }
3436                 }
3437
3438                 // Exempt 'user.cssprefs' module
3439                 // - Position after ResourceLoaderDynamicStyles marker
3440                 $moduleStyles[] = 'user.cssprefs';
3441
3442                 $groups = [
3443                         'other' => [],
3444                         'site' => [],
3445                         'noscript' => [],
3446                         'private' => [],
3447                         'user' => [],
3448                 ];
3449                 foreach ( $moduleStyles as $name ) {
3450                         $module = $resourceLoader->getModule( $name );
3451                         if ( !$module || $module->isKnownEmpty( $this->getRlClientContext() ) ) {
3452                                 // E.g. Don't output empty <styles> for user.cssprefs
3453                                 continue;
3454                         }
3455                         if ( $name === 'site.styles' ) {
3456                                 // HACK: Technically, the 'site.styles' module isn't in a separate request group.
3457                                 // But, in order to ensure its styles are in the right position after the marker,
3458                                 // pretend it's in a group called 'site'.
3459                                 $groups['site'][] = $name;
3460                                 continue;
3461                         }
3462                         $group = $module->getGroup();
3463                         // Use "other" in case. All exempt modules are in one of the known groups though.
3464                         $groups[isset( $groups[$group] ) ? $group : 'other'][] = $name;
3465                 }
3466
3467                 // We want site, private and user styles to override dynamically added
3468                 // styles from modules, but we want dynamically added styles to override
3469                 // statically added styles from other modules. So the order has to be
3470                 // other, dynamic, site, private, user. Add statically added styles for
3471                 // other modules
3472
3473                 // Add legacy styles added through addStyle()/addInlineStyle() here
3474                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3475
3476                 // Client-side mw.loader will inject dynamic styles before this marker.
3477                 $chunks[] = Html::element(
3478                         'meta',
3479                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3480                 );
3481
3482                 foreach ( [ 'other', 'site', 'noscript', 'private', 'user' ] as $group ) {
3483                         $chunks[] = $this->makeResourceLoaderLink( $groups[$group],
3484                                 ResourceLoaderModule::TYPE_STYLES
3485                         );
3486                 }
3487
3488                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3489         }
3490
3491         /**
3492          * @return array
3493          */
3494         public function buildCssLinksArray() {
3495                 $links = [];
3496
3497                 // Add any extension CSS
3498                 foreach ( $this->mExtStyles as $url ) {
3499                         $this->addStyle( $url );
3500                 }
3501                 $this->mExtStyles = [];
3502
3503                 foreach ( $this->styles as $file => $options ) {
3504                         $link = $this->styleLink( $file, $options );
3505                         if ( $link ) {
3506                                 $links[$file] = $link;
3507                         }
3508                 }
3509                 return $links;
3510         }
3511
3512         /**
3513          * Generate \<link\> tags for stylesheets
3514          *
3515          * @param string $style URL to the file
3516          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3517          * @return string HTML fragment
3518          */
3519         protected function styleLink( $style, array $options ) {
3520                 if ( isset( $options['dir'] ) ) {
3521                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3522                                 return '';
3523                         }
3524                 }
3525
3526                 if ( isset( $options['media'] ) ) {
3527                         $media = self::transformCssMedia( $options['media'] );
3528                         if ( is_null( $media ) ) {
3529                                 return '';
3530                         }
3531                 } else {
3532                         $media = 'all';
3533                 }
3534
3535                 if ( substr( $style, 0, 1 ) == '/' ||
3536                         substr( $style, 0, 5 ) == 'http:' ||
3537                         substr( $style, 0, 6 ) == 'https:' ) {
3538                         $url = $style;
3539                 } else {
3540                         $config = $this->getConfig();
3541                         $url = $config->get( 'StylePath' ) . '/' . $style . '?' .
3542                                 $config->get( 'StyleVersion' );
3543                 }
3544
3545                 $link = Html::linkedStyle( $url, $media );
3546
3547                 if ( isset( $options['condition'] ) ) {
3548                         $condition = htmlspecialchars( $options['condition'] );
3549                         $link = "<!--[if $condition]>$link<![endif]-->";
3550                 }
3551                 return $link;
3552         }
3553
3554         /**
3555          * Transform path to web-accessible static resource.
3556          *
3557          * This is used to add a validation hash as query string.
3558          * This aids various behaviors:
3559          *
3560          * - Put long Cache-Control max-age headers on responses for improved
3561          *   cache performance.
3562          * - Get the correct version of a file as expected by the current page.
3563          * - Instantly get the updated version of a file after deployment.
3564          *
3565          * Avoid using this for urls included in HTML as otherwise clients may get different
3566          * versions of a resource when navigating the site depending on when the page was cached.
3567          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3568          * an external stylesheet).
3569          *
3570          * @since 1.27
3571          * @param Config $config
3572          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3573          * @return string URL
3574          */
3575         public static function transformResourcePath( Config $config, $path ) {
3576                 global $IP;
3577                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3578                 if ( $remotePathPrefix === '' ) {
3579                         // The configured base path is required to be empty string for
3580                         // wikis in the domain root
3581                         $remotePath = '/';
3582                 } else {
3583                         $remotePath = $remotePathPrefix;
3584                 }
3585                 if ( strpos( $path, $remotePath ) !== 0 ) {
3586                         // Path is outside wgResourceBasePath, ignore.
3587                         return $path;
3588                 }
3589                 $path = RelPath\getRelativePath( $path, $remotePath );
3590                 return self::transformFilePath( $remotePathPrefix, $IP, $path );
3591         }
3592
3593         /**
3594          * Utility method for transformResourceFilePath().
3595          *
3596          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3597          *
3598          * @since 1.27
3599          * @param string $remotePath URL path prefix that points to $localPath
3600          * @param string $localPath File directory exposed at $remotePath
3601          * @param string $file Path to target file relative to $localPath
3602          * @return string URL
3603          */
3604         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3605                 $hash = md5_file( "$localPath/$file" );
3606                 if ( $hash === false ) {
3607                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3608                         $hash = '';
3609                 }
3610                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3611         }
3612
3613         /**
3614          * Transform "media" attribute based on request parameters
3615          *
3616          * @param string $media Current value of the "media" attribute
3617          * @return string Modified value of the "media" attribute, or null to skip
3618          * this stylesheet
3619          */
3620         public static function transformCssMedia( $media ) {
3621                 global $wgRequest;
3622
3623                 // http://www.w3.org/TR/css3-mediaqueries/#syntax
3624                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3625
3626                 // Switch in on-screen display for media testing
3627                 $switches = [
3628                         'printable' => 'print',
3629                         'handheld' => 'handheld',
3630                 ];
3631                 foreach ( $switches as $switch => $targetMedia ) {
3632                         if ( $wgRequest->getBool( $switch ) ) {
3633                                 if ( $media == $targetMedia ) {
3634                                         $media = '';
3635                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3636                                         /* This regex will not attempt to understand a comma-separated media_query_list
3637                                          *
3638                                          * Example supported values for $media:
3639                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3640                                          * Example NOT supported value for $media:
3641                                          * '3d-glasses, screen, print and resolution > 90dpi'
3642                                          *
3643                                          * If it's a print request, we never want any kind of screen stylesheets
3644                                          * If it's a handheld request (currently the only other choice with a switch),
3645                                          * we don't want simple 'screen' but we might want screen queries that
3646                                          * have a max-width or something, so we'll pass all others on and let the
3647                                          * client do the query.
3648                                          */
3649                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3650                                                 return null;
3651                                         }
3652                                 }
3653                         }
3654                 }
3655
3656                 return $media;
3657         }
3658
3659         /**
3660          * Add a wikitext-formatted message to the output.
3661          * This is equivalent to:
3662          *
3663          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3664          */
3665         public function addWikiMsg( /*...*/ ) {
3666                 $args = func_get_args();
3667                 $name = array_shift( $args );
3668                 $this->addWikiMsgArray( $name, $args );
3669         }
3670
3671         /**
3672          * Add a wikitext-formatted message to the output.
3673          * Like addWikiMsg() except the parameters are taken as an array
3674          * instead of a variable argument list.
3675          *
3676          * @param string $name
3677          * @param array $args
3678          */
3679         public function addWikiMsgArray( $name, $args ) {
3680                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3681         }
3682
3683         /**
3684          * This function takes a number of message/argument specifications, wraps them in
3685          * some overall structure, and then parses the result and adds it to the output.
3686          *
3687          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3688          * and so on. The subsequent arguments may be either
3689          * 1) strings, in which case they are message names, or
3690          * 2) arrays, in which case, within each array, the first element is the message
3691          *    name, and subsequent elements are the parameters to that message.
3692          *
3693          * Don't use this for messages that are not in the user's interface language.
3694          *
3695          * For example:
3696          *
3697          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3698          *
3699          * Is equivalent to:
3700          *
3701          *    $wgOut->addWikiText( "<div class='error'>\n"
3702          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3703          *
3704          * The newline after the opening div is needed in some wikitext. See bug 19226.
3705          *
3706          * @param string $wrap
3707          */
3708         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3709                 $msgSpecs = func_get_args();
3710                 array_shift( $msgSpecs );
3711                 $msgSpecs = array_values( $msgSpecs );
3712                 $s = $wrap;
3713                 foreach ( $msgSpecs as $n => $spec ) {
3714                         if ( is_array( $spec ) ) {
3715                                 $args = $spec;
3716                                 $name = array_shift( $args );
3717                                 if ( isset( $args['options'] ) ) {
3718                                         unset( $args['options'] );
3719                                         wfDeprecated(
3720                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3721                                                 '1.20'
3722                                         );
3723                                 }
3724                         } else {
3725                                 $args = [];
3726                                 $name = $spec;
3727                         }
3728                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3729                 }
3730                 $this->addWikiText( $s );
3731         }
3732
3733         /**
3734          * Enables/disables TOC, doesn't override __NOTOC__
3735          * @param bool $flag
3736          * @since 1.22
3737          */
3738         public function enableTOC( $flag = true ) {
3739                 $this->mEnableTOC = $flag;
3740         }
3741
3742         /**
3743          * @return bool
3744          * @since 1.22
3745          */
3746         public function isTOCEnabled() {
3747                 return $this->mEnableTOC;
3748         }
3749
3750         /**
3751          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3752          * @param bool $flag
3753          * @since 1.23
3754          */
3755         public function enableSectionEditLinks( $flag = true ) {
3756                 $this->mEnableSectionEditLinks = $flag;
3757         }
3758
3759         /**
3760          * @return bool
3761          * @since 1.23
3762          */
3763         public function sectionEditLinksEnabled() {
3764                 return $this->mEnableSectionEditLinks;
3765         }
3766
3767         /**
3768          * Helper function to setup the PHP implementation of OOUI to use in this request.
3769          *
3770          * @since 1.26
3771          * @param String $skinName The Skin name to determine the correct OOUI theme
3772          * @param String $dir Language direction
3773          */
3774         public static function setupOOUI( $skinName = '', $dir = 'ltr' ) {
3775                 $themes = ExtensionRegistry::getInstance()->getAttribute( 'SkinOOUIThemes' );
3776                 // Make keys (skin names) lowercase for case-insensitive matching.
3777                 $themes = array_change_key_case( $themes, CASE_LOWER );
3778                 $theme = isset( $themes[$skinName] ) ? $themes[$skinName] : 'MediaWiki';
3779                 // For example, 'OOUI\MediaWikiTheme'.
3780                 $themeClass = "OOUI\\{$theme}Theme";
3781                 OOUI\Theme::setSingleton( new $themeClass() );
3782                 OOUI\Element::setDefaultDir( $dir );
3783         }
3784
3785         /**
3786          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3787          * MediaWiki and this OutputPage instance.
3788          *
3789          * @since 1.25
3790          */
3791         public function enableOOUI() {
3792                 self::setupOOUI(
3793                         strtolower( $this->getSkin()->getSkinName() ),
3794                         $this->getLanguage()->getDir()
3795                 );
3796                 $this->addModuleStyles( [
3797                         'oojs-ui-core.styles',
3798                         'oojs-ui.styles.icons',
3799                         'oojs-ui.styles.indicators',
3800                         'oojs-ui.styles.textures',
3801                         'mediawiki.widgets.styles',
3802                 ] );
3803                 // Used by 'skipFunction' of the four 'oojs-ui.styles.*' modules. Please don't treat this as a
3804                 // public API or you'll be severely disappointed when T87871 is fixed and it disappears.
3805                 $this->addMeta( 'X-OOUI-PHP', '1' );
3806         }
3807 }