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         /** @var string Stores contents of "<title>" tag */
  71         private $mHTMLtitle = '';
  72
  73         /**
  74          * @var bool Is the displayed content related to the source of the
  75          *   corresponding wiki article.
  76          */
  77         private $mIsarticle = false;
  78
  79         /** @var bool Stores "article flag" toggle. */
  80         private $mIsArticleRelated = true;
  81
  82         /**
  83          * @var bool We have to set isPrintable(). Some pages should
  84          * never be printed (ex: redirections).
  85          */
  86         private $mPrintable = false;
  87
  88         /**
  89          * @var array Contains the page subtitle. Special pages usually have some
  90          *   links here. Don't confuse with site subtitle added by skins.
  91          */
  92         private $mSubtitle = [];
  93
  94         /** @var string */
  95         public $mRedirect = '';
  96
  97         /** @var int */
  98         protected $mStatusCode;
  99
 100         /**
 101          * @var string Used for sending cache control.
 102          *   The whole caching system should probably be moved into its own class.
 103          */
 104         protected $mLastModified = '';
 105
 106         /** @var array */
 107         protected $mCategoryLinks = [];
 108
 109         /** @var array */
 110         protected $mCategories = [];
 111
 112         /** @var array */
 113         protected $mIndicators = [];
 114
 115         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 116         private $mLanguageLinks = [];
 117
 118         /**
 119          * Used for JavaScript (predates ResourceLoader)
 120          * @todo We should split JS / CSS.
 121          * mScripts content is inserted as is in "<head>" by Skin. This might
 122          * contain either a link to a stylesheet or inline CSS.
 123          */
 124         private $mScripts = '';
 125
 126         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 127         protected $mInlineStyles = '';
 128
 129         /**
 130          * @var string Used by skin template.
 131          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 132          */
 133         public $mPageLinkTitle = '';
 134
 135         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 136         protected $mHeadItems = [];
 137
 138         /** @var array */
 139         protected $mModules = [];
 140
 141         /** @var array */
 142         protected $mModuleScripts = [];
 143
 144         /** @var array */
 145         protected $mModuleStyles = [];
 146
 147         /** @var ResourceLoader */
 148         protected $mResourceLoader;
 149
 150         /** @var ResourceLoaderClientHtml */
 151         private $rlClient;
 152
 153         /** @var ResourceLoaderContext */
 154         private $rlClientContext;
 155
 156         /** @var string */
 157         private $rlUserModuleState;
 158
 159         /** @var array */
 160         private $rlExemptStyleModules;
 161
 162         /** @var array */
 163         protected $mJsConfigVars = [];
 164
 165         /** @var array */
 166         protected $mTemplateIds = [];
 167
 168         /** @var array */
 169         protected $mImageTimeKeys = [];
 170
 171         /** @var string */
 172         public $mRedirectCode = '';
 173
 174         protected $mFeedLinksAppendQuery = null;
 175
 176         /** @var array
 177          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 178          * @see ResourceLoaderModule::$origin
 179          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 180          */
 181         protected $mAllowedModules = [
 182                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 183         ];
 184
 185         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 186         protected $mDoNothing = false;
 187
 188         // Parser related.
 189
 190         /** @var int */
 191         protected $mContainsNewMagic = 0;
 192
 193         /**
 194          * lazy initialised, use parserOptions()
 195          * @var ParserOptions
 196          */
 197         protected $mParserOptions = null;
 198
 199         /**
 200          * Handles the Atom / RSS links.
 201          * We probably only support Atom in 2011.
 202          * @see $wgAdvertisedFeedTypes
 203          */
 204         private $mFeedLinks = [];
 205
 206         // Gwicke work on squid caching? Roughly from 2003.
 207         protected $mEnableClientCache = true;
 208
 209         /** @var bool Flag if output should only contain the body of the article. */
 210         private $mArticleBodyOnly = false;
 211
 212         /** @var bool */
 213         protected $mNewSectionLink = false;
 214
 215         /** @var bool */
 216         protected $mHideNewSectionLink = false;
 217
 218         /**
 219          * @var bool Comes from the parser. This was probably made to load CSS/JS
 220          * only if we had "<gallery>". Used directly in CategoryPage.php.
 221          * Looks like ResourceLoader can replace this.
 222          */
 223         public $mNoGallery = false;
 224
 225         /** @var string */
 226         private $mPageTitleActionText = '';
 227
 228         /** @var int Cache stuff. Looks like mEnableClientCache */
 229         protected $mCdnMaxage = 0;
 230         /** @var int Upper limit on mCdnMaxage */
 231         protected $mCdnMaxageLimit = INF;
 232
 233         /**
 234          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 235          * be sent. This should be done for pages where edit actions are possible.
 236          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 237          */
 238         protected $mPreventClickjacking = true;
 239
 240         /** @var int To include the variable {{REVISIONID}} */
 241         private $mRevisionId = null;
 242
 243         /** @var string */
 244         private $mRevisionTimestamp = null;
 245
 246         /** @var array */
 247         protected $mFileVersion = null;
 248
 249         /**
 250          * @var array An array of stylesheet filenames (relative from skins path),
 251          * with options for CSS media, IE conditions, and RTL/LTR direction.
 252          * For internal use; add settings in the skin via $this->addStyle()
 253          *
 254          * Style again! This seems like a code duplication since we already have
 255          * mStyles. This is what makes Open Source amazing.
 256          */
 257         protected $styles = [];
 258
 259         private $mIndexPolicy = 'index';
 260         private $mFollowPolicy = 'follow';
 261         private $mVaryHeader = [
 262                 'Accept-Encoding' => [ 'match=gzip' ],
 263         ];
 264
 265         /**
 266          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 267          * of the redirect.
 268          *
 269          * @var Title
 270          */
 271         private $mRedirectedFrom = null;
 272
 273         /**
 274          * Additional key => value data
 275          */
 276         private $mProperties = [];
 277
 278         /**
 279          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 280          */
 281         private $mTarget = null;
 282
 283         /**
 284          * @var bool Whether parser output should contain table of contents
 285          */
 286         private $mEnableTOC = true;
 287
 288         /**
 289          * @var bool Whether parser output should contain section edit links
 290          */
 291         private $mEnableSectionEditLinks = true;
 292
 293         /**
 294          * @var string|null The URL to send in a <link> element with rel=copyright
 295          */
 296         private $copyrightUrl;
 297
 298         /**
 299          * Constructor for OutputPage. This should not be called directly.
 300          * Instead a new RequestContext should be created and it will implicitly create
 301          * a OutputPage tied to that context.
 302          * @param IContextSource|null $context
 303          */
 304         function __construct( IContextSource $context = null ) {
 305                 if ( $context === null ) {
 306                         # Extensions should use `new RequestContext` instead of `new OutputPage` now.
 307                         wfDeprecated( __METHOD__, '1.18' );
 308                 } else {
 309                         $this->setContext( $context );
 310                 }
 311         }
 312
 313         /**
 314          * Redirect to $url rather than displaying the normal page
 315          *
 316          * @param string $url URL
 317          * @param string $responsecode HTTP status code
 318          */
 319         public function redirect( $url, $responsecode = '302' ) {
 320                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 321                 $this->mRedirect = str_replace( "\n", '', $url );
 322                 $this->mRedirectCode = $responsecode;
 323         }
 324
 325         /**
 326          * Get the URL to redirect to, or an empty string if not redirect URL set
 327          *
 328          * @return string
 329          */
 330         public function getRedirect() {
 331                 return $this->mRedirect;
 332         }
 333
 334         /**
 335          * Set the copyright URL to send with the output.
 336          * Empty string to omit, null to reset.
 337          *
 338          * @since 1.26
 339          *
 340          * @param string|null $url
 341          */
 342         public function setCopyrightUrl( $url ) {
 343                 $this->copyrightUrl = $url;
 344         }
 345
 346         /**
 347          * Set the HTTP status code to send with the output.
 348          *
 349          * @param int $statusCode
 350          */
 351         public function setStatusCode( $statusCode ) {
 352                 $this->mStatusCode = $statusCode;
 353         }
 354
 355         /**
 356          * Add a new "<meta>" tag
 357          * To add an http-equiv meta tag, precede the name with "http:"
 358          *
 359          * @param string $name Tag name
 360          * @param string $val Tag value
 361          */
 362         function addMeta( $name, $val ) {
 363                 array_push( $this->mMetatags, [ $name, $val ] );
 364         }
 365
 366         /**
 367          * Returns the current <meta> tags
 368          *
 369          * @since 1.25
 370          * @return array
 371          */
 372         public function getMetaTags() {
 373                 return $this->mMetatags;
 374         }
 375
 376         /**
 377          * Add a new \<link\> tag to the page header.
 378          *
 379          * Note: use setCanonicalUrl() for rel=canonical.
 380          *
 381          * @param array $linkarr Associative array of attributes.
 382          */
 383         function addLink( array $linkarr ) {
 384                 array_push( $this->mLinktags, $linkarr );
 385         }
 386
 387         /**
 388          * Returns the current <link> tags
 389          *
 390          * @since 1.25
 391          * @return array
 392          */
 393         public function getLinkTags() {
 394                 return $this->mLinktags;
 395         }
 396
 397         /**
 398          * Add a new \<link\> with "rel" attribute set to "meta"
 399          *
 400          * @param array $linkarr Associative array mapping attribute names to their
 401          *                 values, both keys and values will be escaped, and the
 402          *                 "rel" attribute will be automatically added
 403          */
 404         function addMetadataLink( array $linkarr ) {
 405                 $linkarr['rel'] = $this->getMetadataAttribute();
 406                 $this->addLink( $linkarr );
 407         }
 408
 409         /**
 410          * Set the URL to be used for the <link rel=canonical>. This should be used
 411          * in preference to addLink(), to avoid duplicate link tags.
 412          * @param string $url
 413          */
 414         function setCanonicalUrl( $url ) {
 415                 $this->mCanonicalUrl = $url;
 416         }
 417
 418         /**
 419          * Returns the URL to be used for the <link rel=canonical> if
 420          * one is set.
 421          *
 422          * @since 1.25
 423          * @return bool|string
 424          */
 425         public function getCanonicalUrl() {
 426                 return $this->mCanonicalUrl;
 427         }
 428
 429         /**
 430          * Get the value of the "rel" attribute for metadata links
 431          *
 432          * @return string
 433          */
 434         public function getMetadataAttribute() {
 435                 # note: buggy CC software only reads first "meta" link
 436                 static $haveMeta = false;
 437                 if ( $haveMeta ) {
 438                         return 'alternate meta';
 439                 } else {
 440                         $haveMeta = true;
 441                         return 'meta';
 442                 }
 443         }
 444
 445         /**
 446          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 447          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 448          * if possible.
 449          *
 450          * @param string $script Raw HTML
 451          */
 452         function addScript( $script ) {
 453                 $this->mScripts .= $script;
 454         }
 455
 456         /**
 457          * Register and add a stylesheet from an extension directory.
 458          *
 459          * @deprecated since 1.27 use addModuleStyles() or addStyle() instead
 460          * @param string $url Path to sheet.  Provide either a full url (beginning
 461          *             with 'http', etc) or a relative path from the document root
 462          *             (beginning with '/').  Otherwise it behaves identically to
 463          *             addStyle() and draws from the /skins folder.
 464          */
 465         public function addExtensionStyle( $url ) {
 466                 wfDeprecated( __METHOD__, '1.27' );
 467                 array_push( $this->mExtStyles, $url );
 468         }
 469
 470         /**
 471          * Get all styles added by extensions
 472          *
 473          * @deprecated since 1.27
 474          * @return array
 475          */
 476         function getExtStyle() {
 477                 wfDeprecated( __METHOD__, '1.27' );
 478                 return $this->mExtStyles;
 479         }
 480
 481         /**
 482          * Add a JavaScript file out of skins/common, or a given relative path.
 483          * Internal use only. Use OutputPage::addModules() if possible.
 484          *
 485          * @param string $file Filename in skins/common or complete on-server path
 486          *              (/foo/bar.js)
 487          * @param string $version Style version of the file. Defaults to $wgStyleVersion
 488          */
 489         public function addScriptFile( $file, $version = null ) {
 490                 // See if $file parameter is an absolute URL or begins with a slash
 491                 if ( substr( $file, 0, 1 ) == '/' || preg_match( '#^[a-z]*://#i', $file ) ) {
 492                         $path = $file;
 493                 } else {
 494                         $path = $this->getConfig()->get( 'StylePath' ) . "/common/{$file}";
 495                 }
 496                 if ( is_null( $version ) ) {
 497                         $version = $this->getConfig()->get( 'StyleVersion' );
 498                 }
 499                 $this->addScript( Html::linkedScript( wfAppendQuery( $path, $version ) ) );
 500         }
 501
 502         /**
 503          * Add a self-contained script tag with the given contents
 504          * Internal use only. Use OutputPage::addModules() if possible.
 505          *
 506          * @param string $script JavaScript text, no script tags
 507          */
 508         public function addInlineScript( $script ) {
 509                 $this->mScripts .= Html::inlineScript( $script );
 510         }
 511
 512         /**
 513          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 514          * which are no longer registered (eg a page is cached before an extension is disabled)
 515          * @param array $modules
 516          * @param string|null $position If not null, only return modules with this position
 517          * @param string $type
 518          * @return array
 519          */
 520         protected function filterModules( array $modules, $position = null,
 521                 $type = ResourceLoaderModule::TYPE_COMBINED
 522         ) {
 523                 $resourceLoader = $this->getResourceLoader();
 524                 $filteredModules = [];
 525                 foreach ( $modules as $val ) {
 526                         $module = $resourceLoader->getModule( $val );
 527                         if ( $module instanceof ResourceLoaderModule
 528                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 529                                 && ( is_null( $position ) || $module->getPosition() == $position )
 530                                 && ( !$this->mTarget || in_array( $this->mTarget, $module->getTargets() ) )
 531                         ) {
 532                                 $filteredModules[] = $val;
 533                         }
 534                 }
 535                 return $filteredModules;
 536         }
 537
 538         /**
 539          * Get the list of modules to include on this page
 540          *
 541          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 542          * @param string|null $position If not null, only return modules with this position
 543          * @param string $param
 544          * @return array Array of module names
 545          */
 546         public function getModules( $filter = false, $position = null, $param = 'mModules',
 547                 $type = ResourceLoaderModule::TYPE_COMBINED
 548         ) {
 549                 $modules = array_values( array_unique( $this->$param ) );
 550                 return $filter
 551                         ? $this->filterModules( $modules, $position, $type )
 552                         : $modules;
 553         }
 554
 555         /**
 556          * Add one or more modules recognized by ResourceLoader. Modules added
 557          * through this function will be loaded by ResourceLoader when the
 558          * page loads.
 559          *
 560          * @param string|array $modules Module name (string) or array of module names
 561          */
 562         public function addModules( $modules ) {
 563                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 564         }
 565
 566         /**
 567          * Get the list of module JS to include on this page
 568          *
 569          * @param bool $filter
 570          * @param string|null $position
 571          * @return array Array of module names
 572          */
 573         public function getModuleScripts( $filter = false, $position = null ) {
 574                 return $this->getModules( $filter, $position, 'mModuleScripts',
 575                         ResourceLoaderModule::TYPE_SCRIPTS
 576                 );
 577         }
 578
 579         /**
 580          * Add only JS of one or more modules recognized by ResourceLoader. Module
 581          * scripts added through this function will be loaded by ResourceLoader when
 582          * the page loads.
 583          *
 584          * @param string|array $modules Module name (string) or array of module names
 585          */
 586         public function addModuleScripts( $modules ) {
 587                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 588         }
 589
 590         /**
 591          * Get the list of module CSS to include on this page
 592          *
 593          * @param bool $filter
 594          * @param string|null $position
 595          * @return array Array of module names
 596          */
 597         public function getModuleStyles( $filter = false, $position = null ) {
 598                 return $this->getModules( $filter, $position, 'mModuleStyles',
 599                         ResourceLoaderModule::TYPE_STYLES
 600                 );
 601         }
 602
 603         /**
 604          * Add only CSS of one or more modules recognized by ResourceLoader.
 605          *
 606          * Module styles added through this function will be added using standard link CSS
 607          * tags, rather than as a combined Javascript and CSS package. Thus, they will
 608          * load when JavaScript is disabled (unless CSS also happens to be disabled).
 609          *
 610          * @param string|array $modules Module name (string) or array of module names
 611          */
 612         public function addModuleStyles( $modules ) {
 613                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 614         }
 615
 616         /**
 617          * @return null|string ResourceLoader target
 618          */
 619         public function getTarget() {
 620                 return $this->mTarget;
 621         }
 622
 623         /**
 624          * Sets ResourceLoader target for load.php links. If null, will be omitted
 625          *
 626          * @param string|null $target
 627          */
 628         public function setTarget( $target ) {
 629                 $this->mTarget = $target;
 630         }
 631
 632         /**
 633          * Get an array of head items
 634          *
 635          * @return array
 636          */
 637         function getHeadItemsArray() {
 638                 return $this->mHeadItems;
 639         }
 640
 641         /**
 642          * Add or replace a head item to the output
 643          *
 644          * Whenever possible, use more specific options like ResourceLoader modules,
 645          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 646          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 647          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 648          * This would be your very LAST fallback.
 649          *
 650          * @param string $name Item name
 651          * @param string $value Raw HTML
 652          */
 653         public function addHeadItem( $name, $value ) {
 654                 $this->mHeadItems[$name] = $value;
 655         }
 656
 657         /**
 658          * Add one or more head items to the output
 659          *
 660          * @since 1.28
 661          * @param string|string[] $value Raw HTML
 662          */
 663         public function addHeadItems( $values ) {
 664                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 665         }
 666
 667         /**
 668          * Check if the header item $name is already set
 669          *
 670          * @param string $name Item name
 671          * @return bool
 672          */
 673         public function hasHeadItem( $name ) {
 674                 return isset( $this->mHeadItems[$name] );
 675         }
 676
 677         /**
 678          * @deprecated since 1.28 Obsolete - wgUseETag experiment was removed.
 679          * @param string $tag
 680          */
 681         public function setETag( $tag ) {
 682         }
 683
 684         /**
 685          * Set whether the output should only contain the body of the article,
 686          * without any skin, sidebar, etc.
 687          * Used e.g. when calling with "action=render".
 688          *
 689          * @param bool $only Whether to output only the body of the article
 690          */
 691         public function setArticleBodyOnly( $only ) {
 692                 $this->mArticleBodyOnly = $only;
 693         }
 694
 695         /**
 696          * Return whether the output will contain only the body of the article
 697          *
 698          * @return bool
 699          */
 700         public function getArticleBodyOnly() {
 701                 return $this->mArticleBodyOnly;
 702         }
 703
 704         /**
 705          * Set an additional output property
 706          * @since 1.21
 707          *
 708          * @param string $name
 709          * @param mixed $value
 710          */
 711         public function setProperty( $name, $value ) {
 712                 $this->mProperties[$name] = $value;
 713         }
 714
 715         /**
 716          * Get an additional output property
 717          * @since 1.21
 718          *
 719          * @param string $name
 720          * @return mixed Property value or null if not found
 721          */
 722         public function getProperty( $name ) {
 723                 if ( isset( $this->mProperties[$name] ) ) {
 724                         return $this->mProperties[$name];
 725                 } else {
 726                         return null;
 727                 }
 728         }
 729
 730         /**
 731          * checkLastModified tells the client to use the client-cached page if
 732          * possible. If successful, the OutputPage is disabled so that
 733          * any future call to OutputPage->output() have no effect.
 734          *
 735          * Side effect: sets mLastModified for Last-Modified header
 736          *
 737          * @param string $timestamp
 738          *
 739          * @return bool True if cache-ok headers was sent.
 740          */
 741         public function checkLastModified( $timestamp ) {
 742                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 743                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 744                         return false;
 745                 }
 746                 $config = $this->getConfig();
 747                 if ( !$config->get( 'CachePages' ) ) {
 748                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 749                         return false;
 750                 }
 751
 752                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 753                 $modifiedTimes = [
 754                         'page' => $timestamp,
 755                         'user' => $this->getUser()->getTouched(),
 756                         'epoch' => $config->get( 'CacheEpoch' )
 757                 ];
 758                 if ( $config->get( 'UseSquid' ) ) {
 759                         // bug 44570: the core page itself may not change, but resources might
 760                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, time() - $config->get( 'SquidMaxage' ) );
 761                 }
 762                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 763
 764                 $maxModified = max( $modifiedTimes );
 765                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 766
 767                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 768                 if ( $clientHeader === false ) {
 769                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 770                         return false;
 771                 }
 772
 773                 # IE sends sizes after the date like this:
 774                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 775                 # this breaks strtotime().
 776                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 777
 778                 MediaWiki\suppressWarnings(); // E_STRICT system time bitching
 779                 $clientHeaderTime = strtotime( $clientHeader );
 780                 MediaWiki\restoreWarnings();
 781                 if ( !$clientHeaderTime ) {
 782                         wfDebug( __METHOD__
 783                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 784                         return false;
 785                 }
 786                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 787
 788                 # Make debug info
 789                 $info = '';
 790                 foreach ( $modifiedTimes as $name => $value ) {
 791                         if ( $info !== '' ) {
 792                                 $info .= ', ';
 793                         }
 794                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 795                 }
 796
 797                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 798                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 799                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 800                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 801                 if ( $clientHeaderTime < $maxModified ) {
 802                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 803                         return false;
 804                 }
 805
 806                 # Not modified
 807                 # Give a 304 Not Modified response code and disable body output
 808                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 809                 ini_set( 'zlib.output_compression', 0 );
 810                 $this->getRequest()->response()->statusHeader( 304 );
 811                 $this->sendCacheControl();
 812                 $this->disable();
 813
 814                 // Don't output a compressed blob when using ob_gzhandler;
 815                 // it's technically against HTTP spec and seems to confuse
 816                 // Firefox when the response gets split over two packets.
 817                 wfClearOutputBuffers();
 818
 819                 return true;
 820         }
 821
 822         /**
 823          * Override the last modified timestamp
 824          *
 825          * @param string $timestamp New timestamp, in a format readable by
 826          *        wfTimestamp()
 827          */
 828         public function setLastModified( $timestamp ) {
 829                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 830         }
 831
 832         /**
 833          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 834          *
 835          * @param string $policy The literal string to output as the contents of
 836          *   the meta tag.  Will be parsed according to the spec and output in
 837          *   standardized form.
 838          * @return null
 839          */
 840         public function setRobotPolicy( $policy ) {
 841                 $policy = Article::formatRobotPolicy( $policy );
 842
 843                 if ( isset( $policy['index'] ) ) {
 844                         $this->setIndexPolicy( $policy['index'] );
 845                 }
 846                 if ( isset( $policy['follow'] ) ) {
 847                         $this->setFollowPolicy( $policy['follow'] );
 848                 }
 849         }
 850
 851         /**
 852          * Set the index policy for the page, but leave the follow policy un-
 853          * touched.
 854          *
 855          * @param string $policy Either 'index' or 'noindex'.
 856          * @return null
 857          */
 858         public function setIndexPolicy( $policy ) {
 859                 $policy = trim( $policy );
 860                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 861                         $this->mIndexPolicy = $policy;
 862                 }
 863         }
 864
 865         /**
 866          * Set the follow policy for the page, but leave the index policy un-
 867          * touched.
 868          *
 869          * @param string $policy Either 'follow' or 'nofollow'.
 870          * @return null
 871          */
 872         public function setFollowPolicy( $policy ) {
 873                 $policy = trim( $policy );
 874                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 875                         $this->mFollowPolicy = $policy;
 876                 }
 877         }
 878
 879         /**
 880          * Set the new value of the "action text", this will be added to the
 881          * "HTML title", separated from it with " - ".
 882          *
 883          * @param string $text New value of the "action text"
 884          */
 885         public function setPageTitleActionText( $text ) {
 886                 $this->mPageTitleActionText = $text;
 887         }
 888
 889         /**
 890          * Get the value of the "action text"
 891          *
 892          * @return string
 893          */
 894         public function getPageTitleActionText() {
 895                 return $this->mPageTitleActionText;
 896         }
 897
 898         /**
 899          * "HTML title" means the contents of "<title>".
 900          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 901          *
 902          * @param string|Message $name
 903          */
 904         public function setHTMLTitle( $name ) {
 905                 if ( $name instanceof Message ) {
 906                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 907                 } else {
 908                         $this->mHTMLtitle = $name;
 909                 }
 910         }
 911
 912         /**
 913          * Return the "HTML title", i.e. the content of the "<title>" tag.
 914          *
 915          * @return string
 916          */
 917         public function getHTMLTitle() {
 918                 return $this->mHTMLtitle;
 919         }
 920
 921         /**
 922          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 923          *
 924          * @param Title $t
 925          */
 926         public function setRedirectedFrom( $t ) {
 927                 $this->mRedirectedFrom = $t;
 928         }
 929
 930         /**
 931          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 932          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 933          * but not bad tags like \<script\>. This function automatically sets
 934          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 935          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 936          * good tags like \<i\> will be dropped entirely.
 937          *
 938          * @param string|Message $name
 939          */
 940         public function setPageTitle( $name ) {
 941                 if ( $name instanceof Message ) {
 942                         $name = $name->setContext( $this->getContext() )->text();
 943                 }
 944
 945                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 946                 # but leave "<i>foobar</i>" alone
 947                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 948                 $this->mPagetitle = $nameWithTags;
 949
 950                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 951                 $this->setHTMLTitle(
 952                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 953                                 ->inContentLanguage()
 954                 );
 955         }
 956
 957         /**
 958          * Return the "page title", i.e. the content of the \<h1\> tag.
 959          *
 960          * @return string
 961          */
 962         public function getPageTitle() {
 963                 return $this->mPagetitle;
 964         }
 965
 966         /**
 967          * Set the Title object to use
 968          *
 969          * @param Title $t
 970          */
 971         public function setTitle( Title $t ) {
 972                 $this->getContext()->setTitle( $t );
 973         }
 974
 975         /**
 976          * Replace the subtitle with $str
 977          *
 978          * @param string|Message $str New value of the subtitle. String should be safe HTML.
 979          */
 980         public function setSubtitle( $str ) {
 981                 $this->clearSubtitle();
 982                 $this->addSubtitle( $str );
 983         }
 984
 985         /**
 986          * Add $str to the subtitle
 987          *
 988          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
 989          */
 990         public function addSubtitle( $str ) {
 991                 if ( $str instanceof Message ) {
 992                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
 993                 } else {
 994                         $this->mSubtitle[] = $str;
 995                 }
 996         }
 997
 998         /**
 999          * Build message object for a subtitle containing a backlink to a page
1000          *
1001          * @param Title $title Title to link to
1002          * @param array $query Array of additional parameters to include in the link
1003          * @return Message
1004          * @since 1.25
1005          */
1006         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1007                 if ( $title->isRedirect() ) {
1008                         $query['redirect'] = 'no';
1009                 }
1010                 return wfMessage( 'backlinksubtitle' )
1011                         ->rawParams( Linker::link( $title, null, [], $query ) );
1012         }
1013
1014         /**
1015          * Add a subtitle containing a backlink to a page
1016          *
1017          * @param Title $title Title to link to
1018          * @param array $query Array of additional parameters to include in the link
1019          */
1020         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1021                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1022         }
1023
1024         /**
1025          * Clear the subtitles
1026          */
1027         public function clearSubtitle() {
1028                 $this->mSubtitle = [];
1029         }
1030
1031         /**
1032          * Get the subtitle
1033          *
1034          * @return string
1035          */
1036         public function getSubtitle() {
1037                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1038         }
1039
1040         /**
1041          * Set the page as printable, i.e. it'll be displayed with all
1042          * print styles included
1043          */
1044         public function setPrintable() {
1045                 $this->mPrintable = true;
1046         }
1047
1048         /**
1049          * Return whether the page is "printable"
1050          *
1051          * @return bool
1052          */
1053         public function isPrintable() {
1054                 return $this->mPrintable;
1055         }
1056
1057         /**
1058          * Disable output completely, i.e. calling output() will have no effect
1059          */
1060         public function disable() {
1061                 $this->mDoNothing = true;
1062         }
1063
1064         /**
1065          * Return whether the output will be completely disabled
1066          *
1067          * @return bool
1068          */
1069         public function isDisabled() {
1070                 return $this->mDoNothing;
1071         }
1072
1073         /**
1074          * Show an "add new section" link?
1075          *
1076          * @return bool
1077          */
1078         public function showNewSectionLink() {
1079                 return $this->mNewSectionLink;
1080         }
1081
1082         /**
1083          * Forcibly hide the new section link?
1084          *
1085          * @return bool
1086          */
1087         public function forceHideNewSectionLink() {
1088                 return $this->mHideNewSectionLink;
1089         }
1090
1091         /**
1092          * Add or remove feed links in the page header
1093          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1094          * for the new version
1095          * @see addFeedLink()
1096          *
1097          * @param bool $show True: add default feeds, false: remove all feeds
1098          */
1099         public function setSyndicated( $show = true ) {
1100                 if ( $show ) {
1101                         $this->setFeedAppendQuery( false );
1102                 } else {
1103                         $this->mFeedLinks = [];
1104                 }
1105         }
1106
1107         /**
1108          * Add default feeds to the page header
1109          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1110          * for the new version
1111          * @see addFeedLink()
1112          *
1113          * @param string $val Query to append to feed links or false to output
1114          *        default links
1115          */
1116         public function setFeedAppendQuery( $val ) {
1117                 $this->mFeedLinks = [];
1118
1119                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1120                         $query = "feed=$type";
1121                         if ( is_string( $val ) ) {
1122                                 $query .= '&' . $val;
1123                         }
1124                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1125                 }
1126         }
1127
1128         /**
1129          * Add a feed link to the page header
1130          *
1131          * @param string $format Feed type, should be a key of $wgFeedClasses
1132          * @param string $href URL
1133          */
1134         public function addFeedLink( $format, $href ) {
1135                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1136                         $this->mFeedLinks[$format] = $href;
1137                 }
1138         }
1139
1140         /**
1141          * Should we output feed links for this page?
1142          * @return bool
1143          */
1144         public function isSyndicated() {
1145                 return count( $this->mFeedLinks ) > 0;
1146         }
1147
1148         /**
1149          * Return URLs for each supported syndication format for this page.
1150          * @return array Associating format keys with URLs
1151          */
1152         public function getSyndicationLinks() {
1153                 return $this->mFeedLinks;
1154         }
1155
1156         /**
1157          * Will currently always return null
1158          *
1159          * @return null
1160          */
1161         public function getFeedAppendQuery() {
1162                 return $this->mFeedLinksAppendQuery;
1163         }
1164
1165         /**
1166          * Set whether the displayed content is related to the source of the
1167          * corresponding article on the wiki
1168          * Setting true will cause the change "article related" toggle to true
1169          *
1170          * @param bool $v
1171          */
1172         public function setArticleFlag( $v ) {
1173                 $this->mIsarticle = $v;
1174                 if ( $v ) {
1175                         $this->mIsArticleRelated = $v;
1176                 }
1177         }
1178
1179         /**
1180          * Return whether the content displayed page is related to the source of
1181          * the corresponding article on the wiki
1182          *
1183          * @return bool
1184          */
1185         public function isArticle() {
1186                 return $this->mIsarticle;
1187         }
1188
1189         /**
1190          * Set whether this page is related an article on the wiki
1191          * Setting false will cause the change of "article flag" toggle to false
1192          *
1193          * @param bool $v
1194          */
1195         public function setArticleRelated( $v ) {
1196                 $this->mIsArticleRelated = $v;
1197                 if ( !$v ) {
1198                         $this->mIsarticle = false;
1199                 }
1200         }
1201
1202         /**
1203          * Return whether this page is related an article on the wiki
1204          *
1205          * @return bool
1206          */
1207         public function isArticleRelated() {
1208                 return $this->mIsArticleRelated;
1209         }
1210
1211         /**
1212          * Add new language links
1213          *
1214          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1215          *                               (e.g. 'fr:Test page')
1216          */
1217         public function addLanguageLinks( array $newLinkArray ) {
1218                 $this->mLanguageLinks += $newLinkArray;
1219         }
1220
1221         /**
1222          * Reset the language links and add new language links
1223          *
1224          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1225          *                               (e.g. 'fr:Test page')
1226          */
1227         public function setLanguageLinks( array $newLinkArray ) {
1228                 $this->mLanguageLinks = $newLinkArray;
1229         }
1230
1231         /**
1232          * Get the list of language links
1233          *
1234          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1235          */
1236         public function getLanguageLinks() {
1237                 return $this->mLanguageLinks;
1238         }
1239
1240         /**
1241          * Add an array of categories, with names in the keys
1242          *
1243          * @param array $categories Mapping category name => sort key
1244          */
1245         public function addCategoryLinks( array $categories ) {
1246                 global $wgContLang;
1247
1248                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1249                         return;
1250                 }
1251
1252                 # Add the links to a LinkBatch
1253                 $arr = [ NS_CATEGORY => $categories ];
1254                 $lb = new LinkBatch;
1255                 $lb->setArray( $arr );
1256
1257                 # Fetch existence plus the hiddencat property
1258                 $dbr = wfGetDB( DB_REPLICA );
1259                 $fields = array_merge(
1260                         LinkCache::getSelectFields(),
1261                         [ 'page_namespace', 'page_title', 'pp_value' ]
1262                 );
1263
1264                 $res = $dbr->select( [ 'page', 'page_props' ],
1265                         $fields,
1266                         $lb->constructSet( 'page', $dbr ),
1267                         __METHOD__,
1268                         [],
1269                         [ 'page_props' => [ 'LEFT JOIN', [
1270                                 'pp_propname' => 'hiddencat',
1271                                 'pp_page = page_id'
1272                         ] ] ]
1273                 );
1274
1275                 # Add the results to the link cache
1276                 $lb->addResultToCache( LinkCache::singleton(), $res );
1277
1278                 # Set all the values to 'normal'.
1279                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1280
1281                 # Mark hidden categories
1282                 foreach ( $res as $row ) {
1283                         if ( isset( $row->pp_value ) ) {
1284                                 $categories[$row->page_title] = 'hidden';
1285                         }
1286                 }
1287
1288                 # Add the remaining categories to the skin
1289                 if ( Hooks::run(
1290                         'OutputPageMakeCategoryLinks',
1291                         [ &$this, $categories, &$this->mCategoryLinks ] )
1292                 ) {
1293                         foreach ( $categories as $category => $type ) {
1294                                 // array keys will cast numeric category names to ints, so cast back to string
1295                                 $category = (string)$category;
1296                                 $origcategory = $category;
1297                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1298                                 if ( !$title ) {
1299                                         continue;
1300                                 }
1301                                 $wgContLang->findVariantLink( $category, $title, true );
1302                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1303                                         continue;
1304                                 }
1305                                 $text = $wgContLang->convertHtml( $title->getText() );
1306                                 $this->mCategories[] = $title->getText();
1307                                 $this->mCategoryLinks[$type][] = Linker::link( $title, $text );
1308                         }
1309                 }
1310         }
1311
1312         /**
1313          * Reset the category links (but not the category list) and add $categories
1314          *
1315          * @param array $categories Mapping category name => sort key
1316          */
1317         public function setCategoryLinks( array $categories ) {
1318                 $this->mCategoryLinks = [];
1319                 $this->addCategoryLinks( $categories );
1320         }
1321
1322         /**
1323          * Get the list of category links, in a 2-D array with the following format:
1324          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1325          * hidden categories) and $link a HTML fragment with a link to the category
1326          * page
1327          *
1328          * @return array
1329          */
1330         public function getCategoryLinks() {
1331                 return $this->mCategoryLinks;
1332         }
1333
1334         /**
1335          * Get the list of category names this page belongs to
1336          *
1337          * @return array Array of strings
1338          */
1339         public function getCategories() {
1340                 return $this->mCategories;
1341         }
1342
1343         /**
1344          * Add an array of indicators, with their identifiers as array
1345          * keys and HTML contents as values.
1346          *
1347          * In case of duplicate keys, existing values are overwritten.
1348          *
1349          * @param array $indicators
1350          * @since 1.25
1351          */
1352         public function setIndicators( array $indicators ) {
1353                 $this->mIndicators = $indicators + $this->mIndicators;
1354                 // Keep ordered by key
1355                 ksort( $this->mIndicators );
1356         }
1357
1358         /**
1359          * Get the indicators associated with this page.
1360          *
1361          * The array will be internally ordered by item keys.
1362          *
1363          * @return array Keys: identifiers, values: HTML contents
1364          * @since 1.25
1365          */
1366         public function getIndicators() {
1367                 return $this->mIndicators;
1368         }
1369
1370         /**
1371          * Adds help link with an icon via page indicators.
1372          * Link target can be overridden by a local message containing a wikilink:
1373          * the message key is: lowercase action or special page name + '-helppage'.
1374          * @param string $to Target MediaWiki.org page title or encoded URL.
1375          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1376          * @since 1.25
1377          */
1378         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1379                 $this->addModuleStyles( 'mediawiki.helplink' );
1380                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1381
1382                 if ( $overrideBaseUrl ) {
1383                         $helpUrl = $to;
1384                 } else {
1385                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1386                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1387                 }
1388
1389                 $link = Html::rawElement(
1390                         'a',
1391                         [
1392                                 'href' => $helpUrl,
1393                                 'target' => '_blank',
1394                                 'class' => 'mw-helplink',
1395                         ],
1396                         $text
1397                 );
1398
1399                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1400         }
1401
1402         /**
1403          * Do not allow scripts which can be modified by wiki users to load on this page;
1404          * only allow scripts bundled with, or generated by, the software.
1405          * Site-wide styles are controlled by a config setting, since they can be
1406          * used to create a custom skin/theme, but not user-specific ones.
1407          *
1408          * @todo this should be given a more accurate name
1409          */
1410         public function disallowUserJs() {
1411                 $this->reduceAllowedModules(
1412                         ResourceLoaderModule::TYPE_SCRIPTS,
1413                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1414                 );
1415
1416                 // Site-wide styles are controlled by a config setting, see bug 71621
1417                 // for background on why. User styles are never allowed.
1418                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1419                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1420                 } else {
1421                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1422                 }
1423                 $this->reduceAllowedModules(
1424                         ResourceLoaderModule::TYPE_STYLES,
1425                         $styleOrigin
1426                 );
1427         }
1428
1429         /**
1430          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1431          * @see ResourceLoaderModule::$origin
1432          * @param string $type ResourceLoaderModule TYPE_ constant
1433          * @return int ResourceLoaderModule ORIGIN_ class constant
1434          */
1435         public function getAllowedModules( $type ) {
1436                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1437                         return min( array_values( $this->mAllowedModules ) );
1438                 } else {
1439                         return isset( $this->mAllowedModules[$type] )
1440                                 ? $this->mAllowedModules[$type]
1441                                 : ResourceLoaderModule::ORIGIN_ALL;
1442                 }
1443         }
1444
1445         /**
1446          * Limit the highest level of CSS/JS untrustworthiness allowed.
1447          *
1448          * If passed the same or a higher level than the current level of untrustworthiness set, the
1449          * level will remain unchanged.
1450          *
1451          * @param string $type
1452          * @param int $level ResourceLoaderModule class constant
1453          */
1454         public function reduceAllowedModules( $type, $level ) {
1455                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1456         }
1457
1458         /**
1459          * Prepend $text to the body HTML
1460          *
1461          * @param string $text HTML
1462          */
1463         public function prependHTML( $text ) {
1464                 $this->mBodytext = $text . $this->mBodytext;
1465         }
1466
1467         /**
1468          * Append $text to the body HTML
1469          *
1470          * @param string $text HTML
1471          */
1472         public function addHTML( $text ) {
1473                 $this->mBodytext .= $text;
1474         }
1475
1476         /**
1477          * Shortcut for adding an Html::element via addHTML.
1478          *
1479          * @since 1.19
1480          *
1481          * @param string $element
1482          * @param array $attribs
1483          * @param string $contents
1484          */
1485         public function addElement( $element, array $attribs = [], $contents = '' ) {
1486                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1487         }
1488
1489         /**
1490          * Clear the body HTML
1491          */
1492         public function clearHTML() {
1493                 $this->mBodytext = '';
1494         }
1495
1496         /**
1497          * Get the body HTML
1498          *
1499          * @return string HTML
1500          */
1501         public function getHTML() {
1502                 return $this->mBodytext;
1503         }
1504
1505         /**
1506          * Get/set the ParserOptions object to use for wikitext parsing
1507          *
1508          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1509          *   current ParserOption object
1510          * @return ParserOptions
1511          */
1512         public function parserOptions( $options = null ) {
1513                 if ( $options !== null && !empty( $options->isBogus ) ) {
1514                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1515                         // been changed somehow, and keep it if so.
1516                         $anonPO = ParserOptions::newFromAnon();
1517                         $anonPO->setEditSection( false );
1518                         if ( !$options->matches( $anonPO ) ) {
1519                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1520                                 $options->isBogus = false;
1521                         }
1522                 }
1523
1524                 if ( !$this->mParserOptions ) {
1525                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1526                                 // $wgUser isn't unstubbable yet, so don't try to get a
1527                                 // ParserOptions for it. And don't cache this ParserOptions
1528                                 // either.
1529                                 $po = ParserOptions::newFromAnon();
1530                                 $po->setEditSection( false );
1531                                 $po->isBogus = true;
1532                                 if ( $options !== null ) {
1533                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1534                                 }
1535                                 return $po;
1536                         }
1537
1538                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1539                         $this->mParserOptions->setEditSection( false );
1540                 }
1541
1542                 if ( $options !== null && !empty( $options->isBogus ) ) {
1543                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1544                         // thing.
1545                         return wfSetVar( $this->mParserOptions, null, true );
1546                 } else {
1547                         return wfSetVar( $this->mParserOptions, $options );
1548                 }
1549         }
1550
1551         /**
1552          * Set the revision ID which will be seen by the wiki text parser
1553          * for things such as embedded {{REVISIONID}} variable use.
1554          *
1555          * @param int|null $revid An positive integer, or null
1556          * @return mixed Previous value
1557          */
1558         public function setRevisionId( $revid ) {
1559                 $val = is_null( $revid ) ? null : intval( $revid );
1560                 return wfSetVar( $this->mRevisionId, $val );
1561         }
1562
1563         /**
1564          * Get the displayed revision ID
1565          *
1566          * @return int
1567          */
1568         public function getRevisionId() {
1569                 return $this->mRevisionId;
1570         }
1571
1572         /**
1573          * Set the timestamp of the revision which will be displayed. This is used
1574          * to avoid a extra DB call in Skin::lastModified().
1575          *
1576          * @param string|null $timestamp
1577          * @return mixed Previous value
1578          */
1579         public function setRevisionTimestamp( $timestamp ) {
1580                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1581         }
1582
1583         /**
1584          * Get the timestamp of displayed revision.
1585          * This will be null if not filled by setRevisionTimestamp().
1586          *
1587          * @return string|null
1588          */
1589         public function getRevisionTimestamp() {
1590                 return $this->mRevisionTimestamp;
1591         }
1592
1593         /**
1594          * Set the displayed file version
1595          *
1596          * @param File|bool $file
1597          * @return mixed Previous value
1598          */
1599         public function setFileVersion( $file ) {
1600                 $val = null;
1601                 if ( $file instanceof File && $file->exists() ) {
1602                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1603                 }
1604                 return wfSetVar( $this->mFileVersion, $val, true );
1605         }
1606
1607         /**
1608          * Get the displayed file version
1609          *
1610          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1611          */
1612         public function getFileVersion() {
1613                 return $this->mFileVersion;
1614         }
1615
1616         /**
1617          * Get the templates used on this page
1618          *
1619          * @return array (namespace => dbKey => revId)
1620          * @since 1.18
1621          */
1622         public function getTemplateIds() {
1623                 return $this->mTemplateIds;
1624         }
1625
1626         /**
1627          * Get the files used on this page
1628          *
1629          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1630          * @since 1.18
1631          */
1632         public function getFileSearchOptions() {
1633                 return $this->mImageTimeKeys;
1634         }
1635
1636         /**
1637          * Convert wikitext to HTML and add it to the buffer
1638          * Default assumes that the current page title will be used.
1639          *
1640          * @param string $text
1641          * @param bool $linestart Is this the start of a line?
1642          * @param bool $interface Is this text in the user interface language?
1643          * @throws MWException
1644          */
1645         public function addWikiText( $text, $linestart = true, $interface = true ) {
1646                 $title = $this->getTitle(); // Work around E_STRICT
1647                 if ( !$title ) {
1648                         throw new MWException( 'Title is null' );
1649                 }
1650                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1651         }
1652
1653         /**
1654          * Add wikitext with a custom Title object
1655          *
1656          * @param string $text Wikitext
1657          * @param Title $title
1658          * @param bool $linestart Is this the start of a line?
1659          */
1660         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1661                 $this->addWikiTextTitle( $text, $title, $linestart );
1662         }
1663
1664         /**
1665          * Add wikitext with a custom Title object and tidy enabled.
1666          *
1667          * @param string $text Wikitext
1668          * @param Title $title
1669          * @param bool $linestart Is this the start of a line?
1670          */
1671         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1672                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1673         }
1674
1675         /**
1676          * Add wikitext with tidy enabled
1677          *
1678          * @param string $text Wikitext
1679          * @param bool $linestart Is this the start of a line?
1680          */
1681         public function addWikiTextTidy( $text, $linestart = true ) {
1682                 $title = $this->getTitle();
1683                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1684         }
1685
1686         /**
1687          * Add wikitext with a custom Title object
1688          *
1689          * @param string $text Wikitext
1690          * @param Title $title
1691          * @param bool $linestart Is this the start of a line?
1692          * @param bool $tidy Whether to use tidy
1693          * @param bool $interface Whether it is an interface message
1694          *   (for example disables conversion)
1695          */
1696         public function addWikiTextTitle( $text, Title $title, $linestart,
1697                 $tidy = false, $interface = false
1698         ) {
1699                 global $wgParser;
1700
1701                 $popts = $this->parserOptions();
1702                 $oldTidy = $popts->setTidy( $tidy );
1703                 $popts->setInterfaceMessage( (bool)$interface );
1704
1705                 $parserOutput = $wgParser->getFreshParser()->parse(
1706                         $text, $title, $popts,
1707                         $linestart, true, $this->mRevisionId
1708                 );
1709
1710                 $popts->setTidy( $oldTidy );
1711
1712                 $this->addParserOutput( $parserOutput );
1713         }
1714
1715         /**
1716          * Add a ParserOutput object, but without Html.
1717          *
1718          * @deprecated since 1.24, use addParserOutputMetadata() instead.
1719          * @param ParserOutput $parserOutput
1720          */
1721         public function addParserOutputNoText( $parserOutput ) {
1722                 wfDeprecated( __METHOD__, '1.24' );
1723                 $this->addParserOutputMetadata( $parserOutput );
1724         }
1725
1726         /**
1727          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1728          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1729          * and so on.
1730          *
1731          * @since 1.24
1732          * @param ParserOutput $parserOutput
1733          */
1734         public function addParserOutputMetadata( $parserOutput ) {
1735                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1736                 $this->addCategoryLinks( $parserOutput->getCategories() );
1737                 $this->setIndicators( $parserOutput->getIndicators() );
1738                 $this->mNewSectionLink = $parserOutput->getNewSection();
1739                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1740
1741                 if ( !$parserOutput->isCacheable() ) {
1742                         $this->enableClientCache( false );
1743                 }
1744                 $this->mNoGallery = $parserOutput->getNoGallery();
1745                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1746                 $this->addModules( $parserOutput->getModules() );
1747                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1748                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1749                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1750                 $this->mPreventClickjacking = $this->mPreventClickjacking
1751                         || $parserOutput->preventClickjacking();
1752
1753                 // Template versioning...
1754                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1755                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1756                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1757                         } else {
1758                                 $this->mTemplateIds[$ns] = $dbks;
1759                         }
1760                 }
1761                 // File versioning...
1762                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1763                         $this->mImageTimeKeys[$dbk] = $data;
1764                 }
1765
1766                 // Hooks registered in the object
1767                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1768                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1769                         list( $hookName, $data ) = $hookInfo;
1770                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1771                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1772                         }
1773                 }
1774
1775                 // enable OOUI if requested via ParserOutput
1776                 if ( $parserOutput->getEnableOOUI() ) {
1777                         $this->enableOOUI();
1778                 }
1779
1780                 // Link flags are ignored for now, but may in the future be
1781                 // used to mark individual language links.
1782                 $linkFlags = [];
1783                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1784                 Hooks::run( 'OutputPageParserOutput', [ &$this, $parserOutput ] );
1785         }
1786
1787         /**
1788          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1789          * ParserOutput object, without any other metadata.
1790          *
1791          * @since 1.24
1792          * @param ParserOutput $parserOutput
1793          */
1794         public function addParserOutputContent( $parserOutput ) {
1795                 $this->addParserOutputText( $parserOutput );
1796
1797                 $this->addModules( $parserOutput->getModules() );
1798                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1799                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1800
1801                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1802         }
1803
1804         /**
1805          * Add the HTML associated with a ParserOutput object, without any metadata.
1806          *
1807          * @since 1.24
1808          * @param ParserOutput $parserOutput
1809          */
1810         public function addParserOutputText( $parserOutput ) {
1811                 $text = $parserOutput->getText();
1812                 Hooks::run( 'OutputPageBeforeHTML', [ &$this, &$text ] );
1813                 $this->addHTML( $text );
1814         }
1815
1816         /**
1817          * Add everything from a ParserOutput object.
1818          *
1819          * @param ParserOutput $parserOutput
1820          */
1821         function addParserOutput( $parserOutput ) {
1822                 $this->addParserOutputMetadata( $parserOutput );
1823                 $parserOutput->setTOCEnabled( $this->mEnableTOC );
1824
1825                 // Touch section edit links only if not previously disabled
1826                 if ( $parserOutput->getEditSectionTokens() ) {
1827                         $parserOutput->setEditSectionTokens( $this->mEnableSectionEditLinks );
1828                 }
1829
1830                 $this->addParserOutputText( $parserOutput );
1831         }
1832
1833         /**
1834          * Add the output of a QuickTemplate to the output buffer
1835          *
1836          * @param QuickTemplate $template
1837          */
1838         public function addTemplate( &$template ) {
1839                 $this->addHTML( $template->getHTML() );
1840         }
1841
1842         /**
1843          * Parse wikitext and return the HTML.
1844          *
1845          * @param string $text
1846          * @param bool $linestart Is this the start of a line?
1847          * @param bool $interface Use interface language ($wgLang instead of
1848          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1849          *   This also disables LanguageConverter.
1850          * @param Language $language Target language object, will override $interface
1851          * @throws MWException
1852          * @return string HTML
1853          */
1854         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1855                 global $wgParser;
1856
1857                 if ( is_null( $this->getTitle() ) ) {
1858                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1859                 }
1860
1861                 $popts = $this->parserOptions();
1862                 if ( $interface ) {
1863                         $popts->setInterfaceMessage( true );
1864                 }
1865                 if ( $language !== null ) {
1866                         $oldLang = $popts->setTargetLanguage( $language );
1867                 }
1868
1869                 $parserOutput = $wgParser->getFreshParser()->parse(
1870                         $text, $this->getTitle(), $popts,
1871                         $linestart, true, $this->mRevisionId
1872                 );
1873
1874                 if ( $interface ) {
1875                         $popts->setInterfaceMessage( false );
1876                 }
1877                 if ( $language !== null ) {
1878                         $popts->setTargetLanguage( $oldLang );
1879                 }
1880
1881                 return $parserOutput->getText();
1882         }
1883
1884         /**
1885          * Parse wikitext, strip paragraphs, and return the HTML.
1886          *
1887          * @param string $text
1888          * @param bool $linestart Is this the start of a line?
1889          * @param bool $interface Use interface language ($wgLang instead of
1890          *   $wgContLang) while parsing language sensitive magic
1891          *   words like GRAMMAR and PLURAL
1892          * @return string HTML
1893          */
1894         public function parseInline( $text, $linestart = true, $interface = false ) {
1895                 $parsed = $this->parse( $text, $linestart, $interface );
1896                 return Parser::stripOuterParagraph( $parsed );
1897         }
1898
1899         /**
1900          * @param $maxage
1901          * @deprecated since 1.27 Use setCdnMaxage() instead
1902          */
1903         public function setSquidMaxage( $maxage ) {
1904                 $this->setCdnMaxage( $maxage );
1905         }
1906
1907         /**
1908          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1909          *
1910          * @param int $maxage Maximum cache time on the CDN, in seconds.
1911          */
1912         public function setCdnMaxage( $maxage ) {
1913                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1914         }
1915
1916         /**
1917          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1918          *
1919          * @param int $maxage Maximum cache time on the CDN, in seconds
1920          * @since 1.27
1921          */
1922         public function lowerCdnMaxage( $maxage ) {
1923                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1924                 $this->setCdnMaxage( $this->mCdnMaxage );
1925         }
1926
1927         /**
1928          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
1929          *
1930          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
1931          * the TTL is higher the older the $mtime timestamp is. Essentially, the
1932          * TTL is 90% of the age of the object, subject to the min and max.
1933          *
1934          * @param string|integer|float|bool|null $mtime Last-Modified timestamp
1935          * @param integer $minTTL Mimimum TTL in seconds [default: 1 minute]
1936          * @param integer $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
1937          * @return integer TTL in seconds
1938          * @since 1.28
1939          */
1940         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
1941                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
1942                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
1943
1944                 if ( $mtime === null || $mtime === false ) {
1945                         return $minTTL; // entity does not exist
1946                 }
1947
1948                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
1949                 $adaptiveTTL = max( .9 * $age, $minTTL );
1950                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
1951
1952                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
1953
1954                 return $adaptiveTTL;
1955         }
1956
1957         /**
1958          * Use enableClientCache(false) to force it to send nocache headers
1959          *
1960          * @param bool $state
1961          *
1962          * @return bool
1963          */
1964         public function enableClientCache( $state ) {
1965                 return wfSetVar( $this->mEnableClientCache, $state );
1966         }
1967
1968         /**
1969          * Get the list of cookies that will influence on the cache
1970          *
1971          * @return array
1972          */
1973         function getCacheVaryCookies() {
1974                 static $cookies;
1975                 if ( $cookies === null ) {
1976                         $config = $this->getConfig();
1977                         $cookies = array_merge(
1978                                 SessionManager::singleton()->getVaryCookies(),
1979                                 [
1980                                         'forceHTTPS',
1981                                 ],
1982                                 $config->get( 'CacheVaryCookies' )
1983                         );
1984                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
1985                 }
1986                 return $cookies;
1987         }
1988
1989         /**
1990          * Check if the request has a cache-varying cookie header
1991          * If it does, it's very important that we don't allow public caching
1992          *
1993          * @return bool
1994          */
1995         function haveCacheVaryCookies() {
1996                 $request = $this->getRequest();
1997                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
1998                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
1999                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2000                                 return true;
2001                         }
2002                 }
2003                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2004                 return false;
2005         }
2006
2007         /**
2008          * Add an HTTP header that will influence on the cache
2009          *
2010          * @param string $header Header name
2011          * @param string[]|null $option Options for the Key header. See
2012          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2013          * for the list of valid options.
2014          */
2015         public function addVaryHeader( $header, array $option = null ) {
2016                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2017                         $this->mVaryHeader[$header] = [];
2018                 }
2019                 if ( !is_array( $option ) ) {
2020                         $option = [];
2021                 }
2022                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2023         }
2024
2025         /**
2026          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2027          * such as Accept-Encoding or Cookie
2028          *
2029          * @return string
2030          */
2031         public function getVaryHeader() {
2032                 // If we vary on cookies, let's make sure it's always included here too.
2033                 if ( $this->getCacheVaryCookies() ) {
2034                         $this->addVaryHeader( 'Cookie' );
2035                 }
2036
2037                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2038                         $this->addVaryHeader( $header, $options );
2039                 }
2040                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2041         }
2042
2043         /**
2044          * Get a complete Key header
2045          *
2046          * @return string
2047          */
2048         public function getKeyHeader() {
2049                 $cvCookies = $this->getCacheVaryCookies();
2050
2051                 $cookiesOption = [];
2052                 foreach ( $cvCookies as $cookieName ) {
2053                         $cookiesOption[] = 'param=' . $cookieName;
2054                 }
2055                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2056
2057                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2058                         $this->addVaryHeader( $header, $options );
2059                 }
2060
2061                 $headers = [];
2062                 foreach ( $this->mVaryHeader as $header => $option ) {
2063                         $newheader = $header;
2064                         if ( is_array( $option ) && count( $option ) > 0 ) {
2065                                 $newheader .= ';' . implode( ';', $option );
2066                         }
2067                         $headers[] = $newheader;
2068                 }
2069                 $key = 'Key: ' . implode( ',', $headers );
2070
2071                 return $key;
2072         }
2073
2074         /**
2075          * T23672: Add Accept-Language to Vary and Key headers
2076          * if there's no 'variant' parameter existed in GET.
2077          *
2078          * For example:
2079          *   /w/index.php?title=Main_page should always be served; but
2080          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2081          */
2082         function addAcceptLanguage() {
2083                 $title = $this->getTitle();
2084                 if ( !$title instanceof Title ) {
2085                         return;
2086                 }
2087
2088                 $lang = $title->getPageLanguage();
2089                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2090                         $variants = $lang->getVariants();
2091                         $aloption = [];
2092                         foreach ( $variants as $variant ) {
2093                                 if ( $variant === $lang->getCode() ) {
2094                                         continue;
2095                                 } else {
2096                                         $aloption[] = 'substr=' . $variant;
2097
2098                                         // IE and some other browsers use BCP 47 standards in
2099                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2100                                         // We should handle these too.
2101                                         $variantBCP47 = wfBCP47( $variant );
2102                                         if ( $variantBCP47 !== $variant ) {
2103                                                 $aloption[] = 'substr=' . $variantBCP47;
2104                                         }
2105                                 }
2106                         }
2107                         $this->addVaryHeader( 'Accept-Language', $aloption );
2108                 }
2109         }
2110
2111         /**
2112          * Set a flag which will cause an X-Frame-Options header appropriate for
2113          * edit pages to be sent. The header value is controlled by
2114          * $wgEditPageFrameOptions.
2115          *
2116          * This is the default for special pages. If you display a CSRF-protected
2117          * form on an ordinary view page, then you need to call this function.
2118          *
2119          * @param bool $enable
2120          */
2121         public function preventClickjacking( $enable = true ) {
2122                 $this->mPreventClickjacking = $enable;
2123         }
2124
2125         /**
2126          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2127          * This can be called from pages which do not contain any CSRF-protected
2128          * HTML form.
2129          */
2130         public function allowClickjacking() {
2131                 $this->mPreventClickjacking = false;
2132         }
2133
2134         /**
2135          * Get the prevent-clickjacking flag
2136          *
2137          * @since 1.24
2138          * @return bool
2139          */
2140         public function getPreventClickjacking() {
2141                 return $this->mPreventClickjacking;
2142         }
2143
2144         /**
2145          * Get the X-Frame-Options header value (without the name part), or false
2146          * if there isn't one. This is used by Skin to determine whether to enable
2147          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2148          *
2149          * @return string
2150          */
2151         public function getFrameOptions() {
2152                 $config = $this->getConfig();
2153                 if ( $config->get( 'BreakFrames' ) ) {
2154                         return 'DENY';
2155                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2156                         return $config->get( 'EditPageFrameOptions' );
2157                 }
2158                 return false;
2159         }
2160
2161         /**
2162          * Send cache control HTTP headers
2163          */
2164         public function sendCacheControl() {
2165                 $response = $this->getRequest()->response();
2166                 $config = $this->getConfig();
2167
2168                 $this->addVaryHeader( 'Cookie' );
2169                 $this->addAcceptLanguage();
2170
2171                 # don't serve compressed data to clients who can't handle it
2172                 # maintain different caches for logged-in users and non-logged in ones
2173                 $response->header( $this->getVaryHeader() );
2174
2175                 if ( $config->get( 'UseKeyHeader' ) ) {
2176                         $response->header( $this->getKeyHeader() );
2177                 }
2178
2179                 if ( $this->mEnableClientCache ) {
2180                         if (
2181                                 $config->get( 'UseSquid' ) &&
2182                                 !$response->hasCookies() &&
2183                                 !SessionManager::getGlobalSession()->isPersistent() &&
2184                                 !$this->isPrintable() &&
2185                                 $this->mCdnMaxage != 0 &&
2186                                 !$this->haveCacheVaryCookies()
2187                         ) {
2188                                 if ( $config->get( 'UseESI' ) ) {
2189                                         # We'll purge the proxy cache explicitly, but require end user agents
2190                                         # to revalidate against the proxy on each visit.
2191                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2192                                         wfDebug( __METHOD__ .
2193                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2194                                         # start with a shorter timeout for initial testing
2195                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2196                                         $response->header(
2197                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2198                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2199                                         );
2200                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2201                                 } else {
2202                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2203                                         # to revalidate against the proxy on each visit.
2204                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2205                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2206                                         wfDebug( __METHOD__ .
2207                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2208                                         # start with a shorter timeout for initial testing
2209                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2210                                         $response->header( "Cache-Control: " .
2211                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2212                                 }
2213                         } else {
2214                                 # We do want clients to cache if they can, but they *must* check for updates
2215                                 # on revisiting the page.
2216                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2217                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2218                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2219                         }
2220                         if ( $this->mLastModified ) {
2221                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2222                         }
2223                 } else {
2224                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2225
2226                         # In general, the absence of a last modified header should be enough to prevent
2227                         # the client from using its cache. We send a few other things just to make sure.
2228                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2229                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2230                         $response->header( 'Pragma: no-cache' );
2231                 }
2232         }
2233
2234         /**
2235          * Finally, all the text has been munged and accumulated into
2236          * the object, let's actually output it:
2237          *
2238          * @param bool $return Set to true to get the result as a string rather than sending it
2239          * @return string|null
2240          * @throws Exception
2241          * @throws FatalError
2242          * @throws MWException
2243          */
2244         public function output( $return = false ) {
2245                 global $wgContLang;
2246
2247                 if ( $this->mDoNothing ) {
2248                         return $return ? '' : null;
2249                 }
2250
2251                 $response = $this->getRequest()->response();
2252                 $config = $this->getConfig();
2253
2254                 if ( $this->mRedirect != '' ) {
2255                         # Standards require redirect URLs to be absolute
2256                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2257
2258                         $redirect = $this->mRedirect;
2259                         $code = $this->mRedirectCode;
2260
2261                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2262                                 if ( $code == '301' || $code == '303' ) {
2263                                         if ( !$config->get( 'DebugRedirects' ) ) {
2264                                                 $response->statusHeader( $code );
2265                                         }
2266                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2267                                 }
2268                                 if ( $config->get( 'VaryOnXFP' ) ) {
2269                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2270                                 }
2271                                 $this->sendCacheControl();
2272
2273                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2274                                 if ( $config->get( 'DebugRedirects' ) ) {
2275                                         $url = htmlspecialchars( $redirect );
2276                                         print "<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2277                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2278                                         print "</body>\n</html>\n";
2279                                 } else {
2280                                         $response->header( 'Location: ' . $redirect );
2281                                 }
2282                         }
2283
2284                         return $return ? '' : null;
2285                 } elseif ( $this->mStatusCode ) {
2286                         $response->statusHeader( $this->mStatusCode );
2287                 }
2288
2289                 # Buffer output; final headers may depend on later processing
2290                 ob_start();
2291
2292                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2293                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2294
2295                 // Avoid Internet Explorer "compatibility view" in IE 8-10, so that
2296                 // jQuery etc. can work correctly.
2297                 $response->header( 'X-UA-Compatible: IE=Edge' );
2298
2299                 // Prevent framing, if requested
2300                 $frameOptions = $this->getFrameOptions();
2301                 if ( $frameOptions ) {
2302                         $response->header( "X-Frame-Options: $frameOptions" );
2303                 }
2304
2305                 if ( $this->mArticleBodyOnly ) {
2306                         echo $this->mBodytext;
2307                 } else {
2308                         $sk = $this->getSkin();
2309                         // add skin specific modules
2310                         $modules = $sk->getDefaultModules();
2311
2312                         // Enforce various default modules for all pages and all skins
2313                         $coreModules = [
2314                                 // Keep this list as small as possible
2315                                 'site',
2316                                 'mediawiki.page.startup',
2317                                 'mediawiki.user',
2318                         ];
2319
2320                         // Support for high-density display images if enabled
2321                         if ( $config->get( 'ResponsiveImages' ) ) {
2322                                 $coreModules[] = 'mediawiki.hidpi';
2323                         }
2324
2325                         $this->addModules( $coreModules );
2326                         foreach ( $modules as $group ) {
2327                                 $this->addModules( $group );
2328                         }
2329                         MWDebug::addModules( $this );
2330
2331                         // Hook that allows last minute changes to the output page, e.g.
2332                         // adding of CSS or Javascript by extensions.
2333                         Hooks::run( 'BeforePageDisplay', [ &$this, &$sk ] );
2334
2335                         try {
2336                                 $sk->outputPage();
2337                         } catch ( Exception $e ) {
2338                                 ob_end_clean(); // bug T129657
2339                                 throw $e;
2340                         }
2341                 }
2342
2343                 try {
2344                         // This hook allows last minute changes to final overall output by modifying output buffer
2345                         Hooks::run( 'AfterFinalPageOutput', [ $this ] );
2346                 } catch ( Exception $e ) {
2347                         ob_end_clean(); // bug T129657
2348                         throw $e;
2349                 }
2350
2351                 $this->sendCacheControl();
2352
2353                 if ( $return ) {
2354                         return ob_get_clean();
2355                 } else {
2356                         ob_end_flush();
2357                         return null;
2358                 }
2359         }
2360
2361         /**
2362          * Prepare this object to display an error page; disable caching and
2363          * indexing, clear the current text and redirect, set the page's title
2364          * and optionally an custom HTML title (content of the "<title>" tag).
2365          *
2366          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2367          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2368          *                   optional, if not passed the "<title>" attribute will be
2369          *                   based on $pageTitle
2370          */
2371         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2372                 $this->setPageTitle( $pageTitle );
2373                 if ( $htmlTitle !== false ) {
2374                         $this->setHTMLTitle( $htmlTitle );
2375                 }
2376                 $this->setRobotPolicy( 'noindex,nofollow' );
2377                 $this->setArticleRelated( false );
2378                 $this->enableClientCache( false );
2379                 $this->mRedirect = '';
2380                 $this->clearSubtitle();
2381                 $this->clearHTML();
2382         }
2383
2384         /**
2385          * Output a standard error page
2386          *
2387          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2388          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2389          * showErrorPage( 'titlemsg', $messageObject );
2390          * showErrorPage( $titleMessageObject, $messageObject );
2391          *
2392          * @param string|Message $title Message key (string) for page title, or a Message object
2393          * @param string|Message $msg Message key (string) for page text, or a Message object
2394          * @param array $params Message parameters; ignored if $msg is a Message object
2395          */
2396         public function showErrorPage( $title, $msg, $params = [] ) {
2397                 if ( !$title instanceof Message ) {
2398                         $title = $this->msg( $title );
2399                 }
2400
2401                 $this->prepareErrorPage( $title );
2402
2403                 if ( $msg instanceof Message ) {
2404                         if ( $params !== [] ) {
2405                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2406                                         . 'is discarded when the $msg argument is a Message object instead of '
2407                                         . 'a string.', E_USER_NOTICE );
2408                         }
2409                         $this->addHTML( $msg->parseAsBlock() );
2410                 } else {
2411                         $this->addWikiMsgArray( $msg, $params );
2412                 }
2413
2414                 $this->returnToMain();
2415         }
2416
2417         /**
2418          * Output a standard permission error page
2419          *
2420          * @param array $errors Error message keys or [key, param...] arrays
2421          * @param string $action Action that was denied or null if unknown
2422          */
2423         public function showPermissionsErrorPage( array $errors, $action = null ) {
2424                 foreach ( $errors as $key => $error ) {
2425                         $errors[$key] = (array)$error;
2426                 }
2427
2428                 // For some action (read, edit, create and upload), display a "login to do this action"
2429                 // error if all of the following conditions are met:
2430                 // 1. the user is not logged in
2431                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2432                 // 3. the error can be avoided simply by logging in
2433                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2434                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2435                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2436                         && ( User::groupHasPermission( 'user', $action )
2437                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2438                 ) {
2439                         $displayReturnto = null;
2440
2441                         # Due to bug 32276, if a user does not have read permissions,
2442                         # $this->getTitle() will just give Special:Badtitle, which is
2443                         # not especially useful as a returnto parameter. Use the title
2444                         # from the request instead, if there was one.
2445                         $request = $this->getRequest();
2446                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2447                         if ( $action == 'edit' ) {
2448                                 $msg = 'whitelistedittext';
2449                                 $displayReturnto = $returnto;
2450                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2451                                 $msg = 'nocreatetext';
2452                         } elseif ( $action == 'upload' ) {
2453                                 $msg = 'uploadnologintext';
2454                         } else { # Read
2455                                 $msg = 'loginreqpagetext';
2456                                 $displayReturnto = Title::newMainPage();
2457                         }
2458
2459                         $query = [];
2460
2461                         if ( $returnto ) {
2462                                 $query['returnto'] = $returnto->getPrefixedText();
2463
2464                                 if ( !$request->wasPosted() ) {
2465                                         $returntoquery = $request->getValues();
2466                                         unset( $returntoquery['title'] );
2467                                         unset( $returntoquery['returnto'] );
2468                                         unset( $returntoquery['returntoquery'] );
2469                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2470                                 }
2471                         }
2472                         $loginLink = Linker::linkKnown(
2473                                 SpecialPage::getTitleFor( 'Userlogin' ),
2474                                 $this->msg( 'loginreqlink' )->escaped(),
2475                                 [],
2476                                 $query
2477                         );
2478
2479                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2480                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2481
2482                         # Don't return to a page the user can't read otherwise
2483                         # we'll end up in a pointless loop
2484                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2485                                 $this->returnToMain( null, $displayReturnto );
2486                         }
2487                 } else {
2488                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2489                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2490                 }
2491         }
2492
2493         /**
2494          * Display an error page indicating that a given version of MediaWiki is
2495          * required to use it
2496          *
2497          * @param mixed $version The version of MediaWiki needed to use the page
2498          */
2499         public function versionRequired( $version ) {
2500                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2501
2502                 $this->addWikiMsg( 'versionrequiredtext', $version );
2503                 $this->returnToMain();
2504         }
2505
2506         /**
2507          * Format a list of error messages
2508          *
2509          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2510          * @param string $action Action that was denied or null if unknown
2511          * @return string The wikitext error-messages, formatted into a list.
2512          */
2513         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2514                 if ( $action == null ) {
2515                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2516                 } else {
2517                         $action_desc = $this->msg( "action-$action" )->plain();
2518                         $text = $this->msg(
2519                                 'permissionserrorstext-withaction',
2520                                 count( $errors ),
2521                                 $action_desc
2522                         )->plain() . "\n\n";
2523                 }
2524
2525                 if ( count( $errors ) > 1 ) {
2526                         $text .= '<ul class="permissions-errors">' . "\n";
2527
2528                         foreach ( $errors as $error ) {
2529                                 $text .= '<li>';
2530                                 $text .= call_user_func_array( [ $this, 'msg' ], $error )->plain();
2531                                 $text .= "</li>\n";
2532                         }
2533                         $text .= '</ul>';
2534                 } else {
2535                         $text .= "<div class=\"permissions-errors\">\n" .
2536                                         call_user_func_array( [ $this, 'msg' ], reset( $errors ) )->plain() .
2537                                         "\n</div>";
2538                 }
2539
2540                 return $text;
2541         }
2542
2543         /**
2544          * Display a page stating that the Wiki is in read-only mode.
2545          * Should only be called after wfReadOnly() has returned true.
2546          *
2547          * Historically, this function was used to show the source of the page that the user
2548          * was trying to edit and _also_ permissions error messages. The relevant code was
2549          * moved into EditPage in 1.19 (r102024 / d83c2a431c2a) and removed here in 1.25.
2550          *
2551          * @deprecated since 1.25; throw the exception directly
2552          * @throws ReadOnlyError
2553          */
2554         public function readOnlyPage() {
2555                 if ( func_num_args() > 0 ) {
2556                         throw new MWException( __METHOD__ . ' no longer accepts arguments since 1.25.' );
2557                 }
2558
2559                 throw new ReadOnlyError;
2560         }
2561
2562         /**
2563          * Turn off regular page output and return an error response
2564          * for when rate limiting has triggered.
2565          *
2566          * @deprecated since 1.25; throw the exception directly
2567          */
2568         public function rateLimited() {
2569                 wfDeprecated( __METHOD__, '1.25' );
2570                 throw new ThrottledError;
2571         }
2572
2573         /**
2574          * Show a warning about replica DB lag
2575          *
2576          * If the lag is higher than $wgSlaveLagCritical seconds,
2577          * then the warning is a bit more obvious. If the lag is
2578          * lower than $wgSlaveLagWarning, then no warning is shown.
2579          *
2580          * @param int $lag Slave lag
2581          */
2582         public function showLagWarning( $lag ) {
2583                 $config = $this->getConfig();
2584                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2585                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2586                         $message = $lag < $config->get( 'SlaveLagCritical' )
2587                                 ? 'lag-warn-normal'
2588                                 : 'lag-warn-high';
2589                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2590                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2591                 }
2592         }
2593
2594         public function showFatalError( $message ) {
2595                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2596
2597                 $this->addHTML( $message );
2598         }
2599
2600         public function showUnexpectedValueError( $name, $val ) {
2601                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2602         }
2603
2604         public function showFileCopyError( $old, $new ) {
2605                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2606         }
2607
2608         public function showFileRenameError( $old, $new ) {
2609                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2610         }
2611
2612         public function showFileDeleteError( $name ) {
2613                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2614         }
2615
2616         public function showFileNotFoundError( $name ) {
2617                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2618         }
2619
2620         /**
2621          * Add a "return to" link pointing to a specified title
2622          *
2623          * @param Title $title Title to link
2624          * @param array $query Query string parameters
2625          * @param string $text Text of the link (input is not escaped)
2626          * @param array $options Options array to pass to Linker
2627          */
2628         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2629                 $link = $this->msg( 'returnto' )->rawParams(
2630                         Linker::link( $title, $text, [], $query, $options ) )->escaped();
2631                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2632         }
2633
2634         /**
2635          * Add a "return to" link pointing to a specified title,
2636          * or the title indicated in the request, or else the main page
2637          *
2638          * @param mixed $unused
2639          * @param Title|string $returnto Title or String to return to
2640          * @param string $returntoquery Query string for the return to link
2641          */
2642         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2643                 if ( $returnto == null ) {
2644                         $returnto = $this->getRequest()->getText( 'returnto' );
2645                 }
2646
2647                 if ( $returntoquery == null ) {
2648                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2649                 }
2650
2651                 if ( $returnto === '' ) {
2652                         $returnto = Title::newMainPage();
2653                 }
2654
2655                 if ( is_object( $returnto ) ) {
2656                         $titleObj = $returnto;
2657                 } else {
2658                         $titleObj = Title::newFromText( $returnto );
2659                 }
2660                 if ( !is_object( $titleObj ) ) {
2661                         $titleObj = Title::newMainPage();
2662                 }
2663
2664                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2665         }
2666
2667         private function getRlClientContext() {
2668                 if ( !$this->rlClientContext ) {
2669                         $query = ResourceLoader::makeLoaderQuery(
2670                                 [], // modules; not relevant
2671                                 $this->getLanguage()->getCode(),
2672                                 $this->getSkin()->getSkinName(),
2673                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2674                                 null, // version; not relevant
2675                                 ResourceLoader::inDebugMode(),
2676                                 null, // only; not relevant
2677                                 $this->isPrintable(),
2678                                 $this->getRequest()->getBool( 'handheld' )
2679                         );
2680                         $this->rlClientContext = new ResourceLoaderContext(
2681                                 $this->getResourceLoader(),
2682                                 new FauxRequest( $query )
2683                         );
2684                 }
2685                 return $this->rlClientContext;
2686         }
2687
2688         /**
2689          * Call this to freeze the module queue and JS config and create a formatter.
2690          *
2691          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2692          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2693          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2694          * the module filters retroactively. Skins and extension hooks may also add modules until very
2695          * late in the request lifecycle.
2696          *
2697          * @return ResourceLoaderClientHtml
2698          */
2699         public function getRlClient() {
2700                 if ( !$this->rlClient ) {
2701                         $context = $this->getRlClientContext();
2702                         $rl = $this->getResourceLoader();
2703                         $this->addModules( [
2704                                 'user.options',
2705                                 'user.tokens',
2706                         ] );
2707                         $this->addModuleStyles( [
2708                                 'site.styles',
2709                                 'noscript',
2710                                 'user.styles',
2711                                 'user.cssprefs',
2712                         ] );
2713                         $this->getSkin()->setupSkinUserCss( $this );
2714
2715                         // Prepare exempt modules for buildExemptModules()
2716                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2717                         $exemptStates = [];
2718                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2719
2720                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2721                         // Separate user-specific batch for improved cache-hit ratio.
2722                         $userBatch = [ 'user.styles', 'user' ];
2723                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2724                         $dbr = wfGetDB( DB_REPLICA );
2725                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2726                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2727
2728                         // Filter out modules handled by buildExemptModules()
2729                         $moduleStyles = array_filter( $moduleStyles,
2730                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2731                                         $module = $rl->getModule( $name );
2732                                         if ( $module ) {
2733                                                 if ( $name === 'user.styles' && $this->isUserCssPreview() ) {
2734                                                         $exemptStates[$name] = 'ready';
2735                                                         // Special case in buildExemptModules()
2736                                                         return false;
2737                                                 }
2738                                                 $group = $module->getGroup();
2739                                                 if ( isset( $exemptGroups[$group] ) ) {
2740                                                         $exemptStates[$name] = 'ready';
2741                                                         if ( !$module->isKnownEmpty( $context ) ) {
2742                                                                 // E.g. Don't output empty <styles>
2743                                                                 $exemptGroups[$group][] = $name;
2744                                                         }
2745                                                         return false;
2746                                                 }
2747                                         }
2748                                         return true;
2749                                 }
2750                         );
2751                         $this->rlExemptStyleModules = $exemptGroups;
2752
2753                         $isUserModuleFiltered = !$this->filterModules( [ 'user' ] );
2754                         // If this page filters out 'user', makeResourceLoaderLink will drop it.
2755                         // Avoid indefinite "loading" state or untrue "ready" state (T145368).
2756                         if ( !$isUserModuleFiltered ) {
2757                                 // Manually handled by getBottomScripts()
2758                                 $userModule = $rl->getModule( 'user' );
2759                                 $userState = $userModule->isKnownEmpty( $context ) && !$this->isUserJsPreview()
2760                                         ? 'ready'
2761                                         : 'loading';
2762                                 $this->rlUserModuleState = $exemptStates['user'] = $userState;
2763                         }
2764
2765                         $rlClient = new ResourceLoaderClientHtml( $context, $this->getTarget() );
2766                         $rlClient->setConfig( $this->getJSVars() );
2767                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2768                         $rlClient->setModuleStyles( $moduleStyles );
2769                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2770                         $rlClient->setExemptStates( $exemptStates );
2771                         $this->rlClient = $rlClient;
2772                 }
2773                 return $this->rlClient;
2774         }
2775
2776         /**
2777          * @param Skin $sk The given Skin
2778          * @param bool $includeStyle Unused
2779          * @return string The doctype, opening "<html>", and head element.
2780          */
2781         public function headElement( Skin $sk, $includeStyle = true ) {
2782                 global $wgContLang;
2783
2784                 $userdir = $this->getLanguage()->getDir();
2785                 $sitedir = $wgContLang->getDir();
2786
2787                 $pieces = [];
2788                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2789                         $this->getRlClient()->getDocumentAttributes(),
2790                         $sk->getHtmlElementAttributes()
2791                 ) );
2792                 $pieces[] = Html::openElement( 'head' );
2793
2794                 if ( $this->getHTMLTitle() == '' ) {
2795                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2796                 }
2797
2798                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2799                         // Add <meta charset="UTF-8">
2800                         // This should be before <title> since it defines the charset used by
2801                         // text including the text inside <title>.
2802                         // The spec recommends defining XHTML5's charset using the XML declaration
2803                         // instead of meta.
2804                         // Our XML declaration is output by Html::htmlHeader.
2805                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2806                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2807                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2808                 }
2809
2810                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2811                 $pieces[] = $this->getRlClient()->getHeadHtml();
2812                 $pieces[] = $this->buildExemptModules();
2813                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2814                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2815                 $pieces[] = Html::closeElement( 'head' );
2816
2817                 $bodyClasses = [];
2818                 $bodyClasses[] = 'mediawiki';
2819
2820                 # Classes for LTR/RTL directionality support
2821                 $bodyClasses[] = $userdir;
2822                 $bodyClasses[] = "sitedir-$sitedir";
2823
2824                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2825                         # A <body> class is probably not the best way to do this . . .
2826                         $bodyClasses[] = 'capitalize-all-nouns';
2827                 }
2828
2829                 // Parser feature migration class
2830                 // The idea is that this will eventually be removed, after the wikitext
2831                 // which requires it is cleaned up.
2832                 $bodyClasses[] = 'mw-hide-empty-elt';
2833
2834                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2835                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2836                 $bodyClasses[] =
2837                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2838
2839                 $bodyAttrs = [];
2840                 // While the implode() is not strictly needed, it's used for backwards compatibility
2841                 // (this used to be built as a string and hooks likely still expect that).
2842                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2843
2844                 // Allow skins and extensions to add body attributes they need
2845                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2846                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2847
2848                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2849
2850                 return self::combineWrappedStrings( $pieces );
2851         }
2852
2853         /**
2854          * Get a ResourceLoader object associated with this OutputPage
2855          *
2856          * @return ResourceLoader
2857          */
2858         public function getResourceLoader() {
2859                 if ( is_null( $this->mResourceLoader ) ) {
2860                         $this->mResourceLoader = new ResourceLoader(
2861                                 $this->getConfig(),
2862                                 LoggerFactory::getInstance( 'resourceloader' )
2863                         );
2864                 }
2865                 return $this->mResourceLoader;
2866         }
2867
2868         /**
2869          * Explicily load or embed modules on a page.
2870          *
2871          * @param array|string $modules One or more module names
2872          * @param string $only ResourceLoaderModule TYPE_ class constant
2873          * @param array $extraQuery [optional] Array with extra query parameters for the request
2874          * @return string|WrappedStringList HTML
2875          */
2876         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2877                 // Apply 'target' and 'origin' filters
2878                 $modules = $this->filterModules( (array)$modules, null, $only );
2879
2880                 return ResourceLoaderClientHtml::makeLoad(
2881                         $this->getRlClientContext(),
2882                         $modules,
2883                         $only,
2884                         $extraQuery
2885                 );
2886         }
2887
2888         /**
2889          * Combine WrappedString chunks and filter out empty ones
2890          *
2891          * @param array $chunks
2892          * @return string|WrappedStringList HTML
2893          */
2894         protected static function combineWrappedStrings( array $chunks ) {
2895                 // Filter out empty values
2896                 $chunks = array_filter( $chunks, 'strlen' );
2897                 return WrappedString::join( "\n", $chunks );
2898         }
2899
2900         private function isUserJsPreview() {
2901                 return $this->getConfig()->get( 'AllowUserJs' )
2902                         && $this->getTitle()
2903                         && $this->getTitle()->isJsSubpage()
2904                         && $this->userCanPreview();
2905         }
2906
2907         private function isUserCssPreview() {
2908                 return $this->getConfig()->get( 'AllowUserCss' )
2909                         && $this->getTitle()
2910                         && $this->getTitle()->isCssSubpage()
2911                         && $this->userCanPreview();
2912         }
2913
2914         /**
2915          * JS stuff to put at the bottom of the `<body>`. These are modules with position 'bottom',
2916          * legacy scripts ($this->mScripts), and user JS.
2917          *
2918          * @return string|WrappedStringList HTML
2919          */
2920         public function getBottomScripts() {
2921                 $chunks = [];
2922                 $chunks[] = $this->getRlClient()->getBodyHtml();
2923
2924                 // Legacy non-ResourceLoader scripts
2925                 $chunks[] = $this->mScripts;
2926
2927                 // Exempt 'user' module
2928                 // - May need excludepages for live preview. (T28283)
2929                 // - Must use TYPE_COMBINED so its response is handled by mw.loader.implement() which
2930                 //   ensures execution is scheduled after the "site" module.
2931                 // - Don't load if module state is already resolved as "ready".
2932                 if ( $this->rlUserModuleState === 'loading' ) {
2933                         if ( $this->isUserJsPreview() ) {
2934                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED,
2935                                         [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
2936                                 );
2937                                 $chunks[] = ResourceLoader::makeInlineScript(
2938                                         Xml::encodeJsCall( 'mw.loader.using', [
2939                                                 [ 'user', 'site' ],
2940                                                 new XmlJsCode(
2941                                                         'function () {'
2942                                                                 . Xml::encodeJsCall( '$.globalEval', [
2943                                                                         $this->getRequest()->getText( 'wpTextbox1' )
2944                                                                 ] )
2945                                                                 . '}'
2946                                                 )
2947                                         ] )
2948                                 );
2949                                 // FIXME: If the user is previewing, say, ./vector.js, his ./common.js will be loaded
2950                                 // asynchronously and may arrive *after* the inline script here. So the previewed code
2951                                 // may execute before ./common.js runs. Normally, ./common.js runs before ./vector.js.
2952                                 // Similarly, when previewing ./common.js and the user module does arrive first,
2953                                 // it will arrive without common.js and the inline script runs after.
2954                                 // Thus running common after the excluded subpage.
2955                         } else {
2956                                 // Load normally
2957                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED );
2958                         }
2959                 }
2960
2961                 return self::combineWrappedStrings( $chunks );
2962         }
2963
2964         /**
2965          * Get the javascript config vars to include on this page
2966          *
2967          * @return array Array of javascript config vars
2968          * @since 1.23
2969          */
2970         public function getJsConfigVars() {
2971                 return $this->mJsConfigVars;
2972         }
2973
2974         /**
2975          * Add one or more variables to be set in mw.config in JavaScript
2976          *
2977          * @param string|array $keys Key or array of key/value pairs
2978          * @param mixed $value [optional] Value of the configuration variable
2979          */
2980         public function addJsConfigVars( $keys, $value = null ) {
2981                 if ( is_array( $keys ) ) {
2982                         foreach ( $keys as $key => $value ) {
2983                                 $this->mJsConfigVars[$key] = $value;
2984                         }
2985                         return;
2986                 }
2987
2988                 $this->mJsConfigVars[$keys] = $value;
2989         }
2990
2991         /**
2992          * Get an array containing the variables to be set in mw.config in JavaScript.
2993          *
2994          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
2995          * - in other words, page-independent/site-wide variables (without state).
2996          * You will only be adding bloat to the html page and causing page caches to
2997          * have to be purged on configuration changes.
2998          * @return array
2999          */
3000         public function getJSVars() {
3001                 global $wgContLang;
3002
3003                 $curRevisionId = 0;
3004                 $articleId = 0;
3005                 $canonicalSpecialPageName = false; # bug 21115
3006
3007                 $title = $this->getTitle();
3008                 $ns = $title->getNamespace();
3009                 $canonicalNamespace = MWNamespace::exists( $ns )
3010                         ? MWNamespace::getCanonicalName( $ns )
3011                         : $title->getNsText();
3012
3013                 $sk = $this->getSkin();
3014                 // Get the relevant title so that AJAX features can use the correct page name
3015                 // when making API requests from certain special pages (bug 34972).
3016                 $relevantTitle = $sk->getRelevantTitle();
3017                 $relevantUser = $sk->getRelevantUser();
3018
3019                 if ( $ns == NS_SPECIAL ) {
3020                         list( $canonicalSpecialPageName, /*...*/ ) =
3021                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3022                 } elseif ( $this->canUseWikiPage() ) {
3023                         $wikiPage = $this->getWikiPage();
3024                         $curRevisionId = $wikiPage->getLatest();
3025                         $articleId = $wikiPage->getId();
3026                 }
3027
3028                 $lang = $title->getPageViewLanguage();
3029
3030                 // Pre-process information
3031                 $separatorTransTable = $lang->separatorTransformTable();
3032                 $separatorTransTable = $separatorTransTable ? $separatorTransTable : [];
3033                 $compactSeparatorTransTable = [
3034                         implode( "\t", array_keys( $separatorTransTable ) ),
3035                         implode( "\t", $separatorTransTable ),
3036                 ];
3037                 $digitTransTable = $lang->digitTransformTable();
3038                 $digitTransTable = $digitTransTable ? $digitTransTable : [];
3039                 $compactDigitTransTable = [
3040                         implode( "\t", array_keys( $digitTransTable ) ),
3041                         implode( "\t", $digitTransTable ),
3042                 ];
3043
3044                 $user = $this->getUser();
3045
3046                 $vars = [
3047                         'wgCanonicalNamespace' => $canonicalNamespace,
3048                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3049                         'wgNamespaceNumber' => $title->getNamespace(),
3050                         'wgPageName' => $title->getPrefixedDBkey(),
3051                         'wgTitle' => $title->getText(),
3052                         'wgCurRevisionId' => $curRevisionId,
3053                         'wgRevisionId' => (int)$this->getRevisionId(),
3054                         'wgArticleId' => $articleId,
3055                         'wgIsArticle' => $this->isArticle(),
3056                         'wgIsRedirect' => $title->isRedirect(),
3057                         'wgAction' => Action::getActionName( $this->getContext() ),
3058                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3059                         'wgUserGroups' => $user->getEffectiveGroups(),
3060                         'wgCategories' => $this->getCategories(),
3061                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3062                         'wgPageContentLanguage' => $lang->getCode(),
3063                         'wgPageContentModel' => $title->getContentModel(),
3064                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3065                         'wgDigitTransformTable' => $compactDigitTransTable,
3066                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3067                         'wgMonthNames' => $lang->getMonthNamesArray(),
3068                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3069                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3070                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3071                         'wgRequestId' => WebRequest::getRequestId(),
3072                 ];
3073
3074                 if ( $user->isLoggedIn() ) {
3075                         $vars['wgUserId'] = $user->getId();
3076                         $vars['wgUserEditCount'] = $user->getEditCount();
3077                         $userReg = $user->getRegistration();
3078                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3079                         // Get the revision ID of the oldest new message on the user's talk
3080                         // page. This can be used for constructing new message alerts on
3081                         // the client side.
3082                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3083                 }
3084
3085                 if ( $wgContLang->hasVariants() ) {
3086                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3087                 }
3088                 // Same test as SkinTemplate
3089                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3090                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3091
3092                 foreach ( $title->getRestrictionTypes() as $type ) {
3093                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3094                 }
3095
3096                 if ( $title->isMainPage() ) {
3097                         $vars['wgIsMainPage'] = true;
3098                 }
3099
3100                 if ( $this->mRedirectedFrom ) {
3101                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3102                 }
3103
3104                 if ( $relevantUser ) {
3105                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3106                 }
3107
3108                 // Allow extensions to add their custom variables to the mw.config map.
3109                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3110                 // page-dependant but site-wide (without state).
3111                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3112                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3113
3114                 // Merge in variables from addJsConfigVars last
3115                 return array_merge( $vars, $this->getJsConfigVars() );
3116         }
3117
3118         /**
3119          * To make it harder for someone to slip a user a fake
3120          * user-JavaScript or user-CSS preview, a random token
3121          * is associated with the login session. If it's not
3122          * passed back with the preview request, we won't render
3123          * the code.
3124          *
3125          * @return bool
3126          */
3127         public function userCanPreview() {
3128                 $request = $this->getRequest();
3129                 if (
3130                         $request->getVal( 'action' ) !== 'submit' ||
3131                         !$request->getCheck( 'wpPreview' ) ||
3132                         !$request->wasPosted()
3133                 ) {
3134                         return false;
3135                 }
3136
3137                 $user = $this->getUser();
3138
3139                 if ( !$user->isLoggedIn() ) {
3140                         // Anons have predictable edit tokens
3141                         return false;
3142                 }
3143                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3144                         return false;
3145                 }
3146
3147                 $title = $this->getTitle();
3148                 if ( !$title->isJsSubpage() && !$title->isCssSubpage() ) {
3149                         return false;
3150                 }
3151                 if ( !$title->isSubpageOf( $user->getUserPage() ) ) {
3152                         // Don't execute another user's CSS or JS on preview (T85855)
3153                         return false;
3154                 }
3155
3156                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3157                 if ( count( $errors ) !== 0 ) {
3158                         return false;
3159                 }
3160
3161                 return true;
3162         }
3163
3164         /**
3165          * @return array Array in format "link name or number => 'link html'".
3166          */
3167         public function getHeadLinksArray() {
3168                 global $wgVersion;
3169
3170                 $tags = [];
3171                 $config = $this->getConfig();
3172
3173                 $canonicalUrl = $this->mCanonicalUrl;
3174
3175                 $tags['meta-generator'] = Html::element( 'meta', [
3176                         'name' => 'generator',
3177                         'content' => "MediaWiki $wgVersion",
3178                 ] );
3179
3180                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3181                         $tags['meta-referrer'] = Html::element( 'meta', [
3182                                 'name' => 'referrer',
3183                                 'content' => $config->get( 'ReferrerPolicy' )
3184                         ] );
3185                 }
3186
3187                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3188                 if ( $p !== 'index,follow' ) {
3189                         // http://www.robotstxt.org/wc/meta-user.html
3190                         // Only show if it's different from the default robots policy
3191                         $tags['meta-robots'] = Html::element( 'meta', [
3192                                 'name' => 'robots',
3193                                 'content' => $p,
3194                         ] );
3195                 }
3196
3197                 foreach ( $this->mMetatags as $tag ) {
3198                         if ( 0 == strcasecmp( 'http:', substr( $tag[0], 0, 5 ) ) ) {
3199                                 $a = 'http-equiv';
3200                                 $tag[0] = substr( $tag[0], 5 );
3201                         } else {
3202                                 $a = 'name';
3203                         }
3204                         $tagName = "meta-{$tag[0]}";
3205                         if ( isset( $tags[$tagName] ) ) {
3206                                 $tagName .= $tag[1];
3207                         }
3208                         $tags[$tagName] = Html::element( 'meta',
3209                                 [
3210                                         $a => $tag[0],
3211                                         'content' => $tag[1]
3212                                 ]
3213                         );
3214                 }
3215
3216                 foreach ( $this->mLinktags as $tag ) {
3217                         $tags[] = Html::element( 'link', $tag );
3218                 }
3219
3220                 # Universal edit button
3221                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3222                         $user = $this->getUser();
3223                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3224                                 && ( $this->getTitle()->exists() ||
3225                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3226                         ) {
3227                                 // Original UniversalEditButton
3228                                 $msg = $this->msg( 'edit' )->text();
3229                                 $tags['universal-edit-button'] = Html::element( 'link', [
3230                                         'rel' => 'alternate',
3231                                         'type' => 'application/x-wiki',
3232                                         'title' => $msg,
3233                                         'href' => $this->getTitle()->getEditURL(),
3234                                 ] );
3235                                 // Alternate edit link
3236                                 $tags['alternative-edit'] = Html::element( 'link', [
3237                                         'rel' => 'edit',
3238                                         'title' => $msg,
3239                                         'href' => $this->getTitle()->getEditURL(),
3240                                 ] );
3241                         }
3242                 }
3243
3244                 # Generally the order of the favicon and apple-touch-icon links
3245                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3246                 # uses whichever one appears later in the HTML source. Make sure
3247                 # apple-touch-icon is specified first to avoid this.
3248                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3249                         $tags['apple-touch-icon'] = Html::element( 'link', [
3250                                 'rel' => 'apple-touch-icon',
3251                                 'href' => $config->get( 'AppleTouchIcon' )
3252                         ] );
3253                 }
3254
3255                 if ( $config->get( 'Favicon' ) !== false ) {
3256                         $tags['favicon'] = Html::element( 'link', [
3257                                 'rel' => 'shortcut icon',
3258                                 'href' => $config->get( 'Favicon' )
3259                         ] );
3260                 }
3261
3262                 # OpenSearch description link
3263                 $tags['opensearch'] = Html::element( 'link', [
3264                         'rel' => 'search',
3265                         'type' => 'application/opensearchdescription+xml',
3266                         'href' => wfScript( 'opensearch_desc' ),
3267                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3268                 ] );
3269
3270                 if ( $config->get( 'EnableAPI' ) ) {
3271                         # Real Simple Discovery link, provides auto-discovery information
3272                         # for the MediaWiki API (and potentially additional custom API
3273                         # support such as WordPress or Twitter-compatible APIs for a
3274                         # blogging extension, etc)
3275                         $tags['rsd'] = Html::element( 'link', [
3276                                 'rel' => 'EditURI',
3277                                 'type' => 'application/rsd+xml',
3278                                 // Output a protocol-relative URL here if $wgServer is protocol-relative.
3279                                 // Whether RSD accepts relative or protocol-relative URLs is completely
3280                                 // undocumented, though.
3281                                 'href' => wfExpandUrl( wfAppendQuery(
3282                                         wfScript( 'api' ),
3283                                         [ 'action' => 'rsd' ] ),
3284                                         PROTO_RELATIVE
3285                                 ),
3286                         ] );
3287                 }
3288
3289                 # Language variants
3290                 if ( !$config->get( 'DisableLangConversion' ) ) {
3291                         $lang = $this->getTitle()->getPageLanguage();
3292                         if ( $lang->hasVariants() ) {
3293                                 $variants = $lang->getVariants();
3294                                 foreach ( $variants as $variant ) {
3295                                         $tags["variant-$variant"] = Html::element( 'link', [
3296                                                 'rel' => 'alternate',
3297                                                 'hreflang' => wfBCP47( $variant ),
3298                                                 'href' => $this->getTitle()->getLocalURL(
3299                                                         [ 'variant' => $variant ] )
3300                                                 ]
3301                                         );
3302                                 }
3303                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3304                                 $tags["variant-x-default"] = Html::element( 'link', [
3305                                         'rel' => 'alternate',
3306                                         'hreflang' => 'x-default',
3307                                         'href' => $this->getTitle()->getLocalURL() ] );
3308                         }
3309                 }
3310
3311                 # Copyright
3312                 if ( $this->copyrightUrl !== null ) {
3313                         $copyright = $this->copyrightUrl;
3314                 } else {
3315                         $copyright = '';
3316                         if ( $config->get( 'RightsPage' ) ) {
3317                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3318
3319                                 if ( $copy ) {
3320                                         $copyright = $copy->getLocalURL();
3321                                 }
3322                         }
3323
3324                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3325                                 $copyright = $config->get( 'RightsUrl' );
3326                         }
3327                 }
3328
3329                 if ( $copyright ) {
3330                         $tags['copyright'] = Html::element( 'link', [
3331                                 'rel' => 'copyright',
3332                                 'href' => $copyright ]
3333                         );
3334                 }
3335
3336                 # Feeds
3337                 if ( $config->get( 'Feed' ) ) {
3338                         $feedLinks = [];
3339
3340                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3341                                 # Use the page name for the title.  In principle, this could
3342                                 # lead to issues with having the same name for different feeds
3343                                 # corresponding to the same page, but we can't avoid that at
3344                                 # this low a level.
3345
3346                                 $feedLinks[] = $this->feedLink(
3347                                         $format,
3348                                         $link,
3349                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3350                                         $this->msg(
3351                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3352                                         )->text()
3353                                 );
3354                         }
3355
3356                         # Recent changes feed should appear on every page (except recentchanges,
3357                         # that would be redundant). Put it after the per-page feed to avoid
3358                         # changing existing behavior. It's still available, probably via a
3359                         # menu in your browser. Some sites might have a different feed they'd
3360                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3361                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3362                         # If so, use it instead.
3363                         $sitename = $config->get( 'Sitename' );
3364                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3365                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3366                                         // Note, this->feedLink escapes the url.
3367                                         $feedLinks[] = $this->feedLink(
3368                                                 $type,
3369                                                 $feedUrl,
3370                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3371                                         );
3372                                 }
3373                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3374                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3375                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3376                                         $feedLinks[] = $this->feedLink(
3377                                                 $format,
3378                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3379                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3380                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3381                                         );
3382                                 }
3383                         }
3384
3385                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3386                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3387                         # use OutputPage::addFeedLink() instead.
3388                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3389
3390                         $tags += $feedLinks;
3391                 }
3392
3393                 # Canonical URL
3394                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3395                         if ( $canonicalUrl !== false ) {
3396                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3397                         } else {
3398                                 if ( $this->isArticleRelated() ) {
3399                                         // This affects all requests where "setArticleRelated" is true. This is
3400                                         // typically all requests that show content (query title, curid, oldid, diff),
3401                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3402                                         // It does not apply to File pages and Special pages.
3403                                         // 'history' and 'info' actions address page metadata rather than the page
3404                                         // content itself, so they may not be canonicalized to the view page url.
3405                                         // TODO: this ought to be better encapsulated in the Action class.
3406                                         $action = Action::getActionName( $this->getContext() );
3407                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3408                                                 $query = "action={$action}";
3409                                         } else {
3410                                                 $query = '';
3411                                         }
3412                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3413                                 } else {
3414                                         $reqUrl = $this->getRequest()->getRequestURL();
3415                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3416                                 }
3417                         }
3418                 }
3419                 if ( $canonicalUrl !== false ) {
3420                         $tags[] = Html::element( 'link', [
3421                                 'rel' => 'canonical',
3422                                 'href' => $canonicalUrl
3423                         ] );
3424                 }
3425
3426                 return $tags;
3427         }
3428
3429         /**
3430          * @return string HTML tag links to be put in the header.
3431          * @deprecated since 1.24 Use OutputPage::headElement or if you have to,
3432          *   OutputPage::getHeadLinksArray directly.
3433          */
3434         public function getHeadLinks() {
3435                 wfDeprecated( __METHOD__, '1.24' );
3436                 return implode( "\n", $this->getHeadLinksArray() );
3437         }
3438
3439         /**
3440          * Generate a "<link rel/>" for a feed.
3441          *
3442          * @param string $type Feed type
3443          * @param string $url URL to the feed
3444          * @param string $text Value of the "title" attribute
3445          * @return string HTML fragment
3446          */
3447         private function feedLink( $type, $url, $text ) {
3448                 return Html::element( 'link', [
3449                         'rel' => 'alternate',
3450                         'type' => "application/$type+xml",
3451                         'title' => $text,
3452                         'href' => $url ]
3453                 );
3454         }
3455
3456         /**
3457          * Add a local or specified stylesheet, with the given media options.
3458          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3459          *
3460          * @param string $style URL to the file
3461          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3462          * @param string $condition For IE conditional comments, specifying an IE version
3463          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3464          */
3465         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3466                 $options = [];
3467                 if ( $media ) {
3468                         $options['media'] = $media;
3469                 }
3470                 if ( $condition ) {
3471                         $options['condition'] = $condition;
3472                 }
3473                 if ( $dir ) {
3474                         $options['dir'] = $dir;
3475                 }
3476                 $this->styles[$style] = $options;
3477         }
3478
3479         /**
3480          * Adds inline CSS styles
3481          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3482          *
3483          * @param mixed $style_css Inline CSS
3484          * @param string $flip Set to 'flip' to flip the CSS if needed
3485          */
3486         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3487                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3488                         # If wanted, and the interface is right-to-left, flip the CSS
3489                         $style_css = CSSJanus::transform( $style_css, true, false );
3490                 }
3491                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3492         }
3493
3494         /**
3495          * Build exempt modules and legacy non-ResourceLoader styles.
3496          *
3497          * @return string|WrappedStringList HTML
3498          */
3499         protected function buildExemptModules() {
3500                 global $wgContLang;
3501
3502                 $resourceLoader = $this->getResourceLoader();
3503                 $chunks = [];
3504                 // Things that go after the ResourceLoaderDynamicStyles marker
3505                 $append = [];
3506
3507                 // Exempt 'user' styles module (may need 'excludepages' for live preview)
3508                 if ( $this->isUserCssPreview() ) {
3509                         $append[] = $this->makeResourceLoaderLink(
3510                                 'user.styles',
3511                                 ResourceLoaderModule::TYPE_STYLES,
3512                                 [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3513                         );
3514
3515                         // Load the previewed CSS. Janus it if needed.
3516                         // User-supplied CSS is assumed to in the wiki's content language.
3517                         $previewedCSS = $this->getRequest()->getText( 'wpTextbox1' );
3518                         if ( $this->getLanguage()->getDir() !== $wgContLang->getDir() ) {
3519                                 $previewedCSS = CSSJanus::transform( $previewedCSS, true, false );
3520                         }
3521                         $append[] = Html::inlineStyle( $previewedCSS );
3522                 }
3523
3524                 // We want site, private and user styles to override dynamically added styles from
3525                 // general modules, but we want dynamically added styles to override statically added
3526                 // style modules. So the order has to be:
3527                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3528                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3529                 // - ResourceLoaderDynamicStyles marker
3530                 // - site/private/user styles
3531
3532                 // Add legacy styles added through addStyle()/addInlineStyle() here
3533                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3534
3535                 $chunks[] = Html::element(
3536                         'meta',
3537                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3538                 );
3539
3540                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3541                         $chunks[] = $this->makeResourceLoaderLink( $moduleNames,
3542                                 ResourceLoaderModule::TYPE_STYLES
3543                         );
3544                 }
3545
3546                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3547         }
3548
3549         /**
3550          * @return array
3551          */
3552         public function buildCssLinksArray() {
3553                 $links = [];
3554
3555                 // Add any extension CSS
3556                 foreach ( $this->mExtStyles as $url ) {
3557                         $this->addStyle( $url );
3558                 }
3559                 $this->mExtStyles = [];
3560
3561                 foreach ( $this->styles as $file => $options ) {
3562                         $link = $this->styleLink( $file, $options );
3563                         if ( $link ) {
3564                                 $links[$file] = $link;
3565                         }
3566                 }
3567                 return $links;
3568         }
3569
3570         /**
3571          * Generate \<link\> tags for stylesheets
3572          *
3573          * @param string $style URL to the file
3574          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3575          * @return string HTML fragment
3576          */
3577         protected function styleLink( $style, array $options ) {
3578                 if ( isset( $options['dir'] ) ) {
3579                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3580                                 return '';
3581                         }
3582                 }
3583
3584                 if ( isset( $options['media'] ) ) {
3585                         $media = self::transformCssMedia( $options['media'] );
3586                         if ( is_null( $media ) ) {
3587                                 return '';
3588                         }
3589                 } else {
3590                         $media = 'all';
3591                 }
3592
3593                 if ( substr( $style, 0, 1 ) == '/' ||
3594                         substr( $style, 0, 5 ) == 'http:' ||
3595                         substr( $style, 0, 6 ) == 'https:' ) {
3596                         $url = $style;
3597                 } else {
3598                         $config = $this->getConfig();
3599                         $url = $config->get( 'StylePath' ) . '/' . $style . '?' .
3600                                 $config->get( 'StyleVersion' );
3601                 }
3602
3603                 $link = Html::linkedStyle( $url, $media );
3604
3605                 if ( isset( $options['condition'] ) ) {
3606                         $condition = htmlspecialchars( $options['condition'] );
3607                         $link = "<!--[if $condition]>$link<![endif]-->";
3608                 }
3609                 return $link;
3610         }
3611
3612         /**
3613          * Transform path to web-accessible static resource.
3614          *
3615          * This is used to add a validation hash as query string.
3616          * This aids various behaviors:
3617          *
3618          * - Put long Cache-Control max-age headers on responses for improved
3619          *   cache performance.
3620          * - Get the correct version of a file as expected by the current page.
3621          * - Instantly get the updated version of a file after deployment.
3622          *
3623          * Avoid using this for urls included in HTML as otherwise clients may get different
3624          * versions of a resource when navigating the site depending on when the page was cached.
3625          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3626          * an external stylesheet).
3627          *
3628          * @since 1.27
3629          * @param Config $config
3630          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3631          * @return string URL
3632          */
3633         public static function transformResourcePath( Config $config, $path ) {
3634                 global $IP;
3635                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3636                 if ( $remotePathPrefix === '' ) {
3637                         // The configured base path is required to be empty string for
3638                         // wikis in the domain root
3639                         $remotePath = '/';
3640                 } else {
3641                         $remotePath = $remotePathPrefix;
3642                 }
3643                 if ( strpos( $path, $remotePath ) !== 0 ) {
3644                         // Path is outside wgResourceBasePath, ignore.
3645                         return $path;
3646                 }
3647                 $path = RelPath\getRelativePath( $path, $remotePath );
3648                 return self::transformFilePath( $remotePathPrefix, $IP, $path );
3649         }
3650
3651         /**
3652          * Utility method for transformResourceFilePath().
3653          *
3654          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3655          *
3656          * @since 1.27
3657          * @param string $remotePath URL path prefix that points to $localPath
3658          * @param string $localPath File directory exposed at $remotePath
3659          * @param string $file Path to target file relative to $localPath
3660          * @return string URL
3661          */
3662         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3663                 $hash = md5_file( "$localPath/$file" );
3664                 if ( $hash === false ) {
3665                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3666                         $hash = '';
3667                 }
3668                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3669         }
3670
3671         /**
3672          * Transform "media" attribute based on request parameters
3673          *
3674          * @param string $media Current value of the "media" attribute
3675          * @return string Modified value of the "media" attribute, or null to skip
3676          * this stylesheet
3677          */
3678         public static function transformCssMedia( $media ) {
3679                 global $wgRequest;
3680
3681                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3682                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3683
3684                 // Switch in on-screen display for media testing
3685                 $switches = [
3686                         'printable' => 'print',
3687                         'handheld' => 'handheld',
3688                 ];
3689                 foreach ( $switches as $switch => $targetMedia ) {
3690                         if ( $wgRequest->getBool( $switch ) ) {
3691                                 if ( $media == $targetMedia ) {
3692                                         $media = '';
3693                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3694                                         /* This regex will not attempt to understand a comma-separated media_query_list
3695                                          *
3696                                          * Example supported values for $media:
3697                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3698                                          * Example NOT supported value for $media:
3699                                          * '3d-glasses, screen, print and resolution > 90dpi'
3700                                          *
3701                                          * If it's a print request, we never want any kind of screen stylesheets
3702                                          * If it's a handheld request (currently the only other choice with a switch),
3703                                          * we don't want simple 'screen' but we might want screen queries that
3704                                          * have a max-width or something, so we'll pass all others on and let the
3705                                          * client do the query.
3706                                          */
3707                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3708                                                 return null;
3709                                         }
3710                                 }
3711                         }
3712                 }
3713
3714                 return $media;
3715         }
3716
3717         /**
3718          * Add a wikitext-formatted message to the output.
3719          * This is equivalent to:
3720          *
3721          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3722          */
3723         public function addWikiMsg( /*...*/ ) {
3724                 $args = func_get_args();
3725                 $name = array_shift( $args );
3726                 $this->addWikiMsgArray( $name, $args );
3727         }
3728
3729         /**
3730          * Add a wikitext-formatted message to the output.
3731          * Like addWikiMsg() except the parameters are taken as an array
3732          * instead of a variable argument list.
3733          *
3734          * @param string $name
3735          * @param array $args
3736          */
3737         public function addWikiMsgArray( $name, $args ) {
3738                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3739         }
3740
3741         /**
3742          * This function takes a number of message/argument specifications, wraps them in
3743          * some overall structure, and then parses the result and adds it to the output.
3744          *
3745          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3746          * and so on. The subsequent arguments may be either
3747          * 1) strings, in which case they are message names, or
3748          * 2) arrays, in which case, within each array, the first element is the message
3749          *    name, and subsequent elements are the parameters to that message.
3750          *
3751          * Don't use this for messages that are not in the user's interface language.
3752          *
3753          * For example:
3754          *
3755          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3756          *
3757          * Is equivalent to:
3758          *
3759          *    $wgOut->addWikiText( "<div class='error'>\n"
3760          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3761          *
3762          * The newline after the opening div is needed in some wikitext. See bug 19226.
3763          *
3764          * @param string $wrap
3765          */
3766         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3767                 $msgSpecs = func_get_args();
3768                 array_shift( $msgSpecs );
3769                 $msgSpecs = array_values( $msgSpecs );
3770                 $s = $wrap;
3771                 foreach ( $msgSpecs as $n => $spec ) {
3772                         if ( is_array( $spec ) ) {
3773                                 $args = $spec;
3774                                 $name = array_shift( $args );
3775                                 if ( isset( $args['options'] ) ) {
3776                                         unset( $args['options'] );
3777                                         wfDeprecated(
3778                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3779                                                 '1.20'
3780                                         );
3781                                 }
3782                         } else {
3783                                 $args = [];
3784                                 $name = $spec;
3785                         }
3786                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3787                 }
3788                 $this->addWikiText( $s );
3789         }
3790
3791         /**
3792          * Enables/disables TOC, doesn't override __NOTOC__
3793          * @param bool $flag
3794          * @since 1.22
3795          */
3796         public function enableTOC( $flag = true ) {
3797                 $this->mEnableTOC = $flag;
3798         }
3799
3800         /**
3801          * @return bool
3802          * @since 1.22
3803          */
3804         public function isTOCEnabled() {
3805                 return $this->mEnableTOC;
3806         }
3807
3808         /**
3809          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3810          * @param bool $flag
3811          * @since 1.23
3812          */
3813         public function enableSectionEditLinks( $flag = true ) {
3814                 $this->mEnableSectionEditLinks = $flag;
3815         }
3816
3817         /**
3818          * @return bool
3819          * @since 1.23
3820          */
3821         public function sectionEditLinksEnabled() {
3822                 return $this->mEnableSectionEditLinks;
3823         }
3824
3825         /**
3826          * Helper function to setup the PHP implementation of OOUI to use in this request.
3827          *
3828          * @since 1.26
3829          * @param String $skinName The Skin name to determine the correct OOUI theme
3830          * @param String $dir Language direction
3831          */
3832         public static function setupOOUI( $skinName = '', $dir = 'ltr' ) {
3833                 $themes = ExtensionRegistry::getInstance()->getAttribute( 'SkinOOUIThemes' );
3834                 // Make keys (skin names) lowercase for case-insensitive matching.
3835                 $themes = array_change_key_case( $themes, CASE_LOWER );
3836                 $theme = isset( $themes[$skinName] ) ? $themes[$skinName] : 'MediaWiki';
3837                 // For example, 'OOUI\MediaWikiTheme'.
3838                 $themeClass = "OOUI\\{$theme}Theme";
3839                 OOUI\Theme::setSingleton( new $themeClass() );
3840                 OOUI\Element::setDefaultDir( $dir );
3841         }
3842
3843         /**
3844          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3845          * MediaWiki and this OutputPage instance.
3846          *
3847          * @since 1.25
3848          */
3849         public function enableOOUI() {
3850                 self::setupOOUI(
3851                         strtolower( $this->getSkin()->getSkinName() ),
3852                         $this->getLanguage()->getDir()
3853                 );
3854                 $this->addModuleStyles( [
3855                         'oojs-ui-core.styles',
3856                         'oojs-ui.styles.icons',
3857                         'oojs-ui.styles.indicators',
3858                         'oojs-ui.styles.textures',
3859                         'mediawiki.widgets.styles',
3860                 ] );
3861         }
3862 }