includes/OutputPage.php

   1 <?php
   2 /**
   3  * Preparation for the final page rendering.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use MediaWiki\Logger\LoggerFactory;
  24 use MediaWiki\MediaWikiServices;
  25 use MediaWiki\Session\SessionManager;
  26 use WrappedString\WrappedString;
  27 use WrappedString\WrappedStringList;
  28
  29 /**
  30  * This class should be covered by a general architecture document which does
  31  * not exist as of January 2011.  This is one of the Core classes and should
  32  * be read at least once by any new developers.
  33  *
  34  * This class is used to prepare the final rendering. A skin is then
  35  * applied to the output parameters (links, javascript, html, categories ...).
  36  *
  37  * @todo FIXME: Another class handles sending the whole page to the client.
  38  *
  39  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  40  * in November 2010.
  41  *
  42  * @todo document
  43  */
  44 class OutputPage extends ContextSource {
  45         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  46         protected $mMetatags = [];
  47
  48         /** @var array */
  49         protected $mLinktags = [];
  50
  51         /** @var bool */
  52         protected $mCanonicalUrl = false;
  53
  54         /**
  55          * @var array Additional stylesheets. Looks like this is for extensions.
  56          *   Might be replaced by ResourceLoader.
  57          */
  58         protected $mExtStyles = [];
  59
  60         /**
  61          * @var string Should be private - has getter and setter. Contains
  62          *   the HTML title */
  63         public $mPagetitle = '';
  64
  65         /**
  66          * @var string Contains all of the "<body>" content. Should be private we
  67          *   got set/get accessors and the append() method.
  68          */
  69         public $mBodytext = '';
  70
  71         /** @var string Stores contents of "<title>" tag */
  72         private $mHTMLtitle = '';
  73
  74         /**
  75          * @var bool Is the displayed content related to the source of the
  76          *   corresponding wiki article.
  77          */
  78         private $mIsarticle = false;
  79
  80         /** @var bool Stores "article flag" toggle. */
  81         private $mIsArticleRelated = true;
  82
  83         /**
  84          * @var bool We have to set isPrintable(). Some pages should
  85          * never be printed (ex: redirections).
  86          */
  87         private $mPrintable = false;
  88
  89         /**
  90          * @var array Contains the page subtitle. Special pages usually have some
  91          *   links here. Don't confuse with site subtitle added by skins.
  92          */
  93         private $mSubtitle = [];
  94
  95         /** @var string */
  96         public $mRedirect = '';
  97
  98         /** @var int */
  99         protected $mStatusCode;
 100
 101         /**
 102          * @var string Used for sending cache control.
 103          *   The whole caching system should probably be moved into its own class.
 104          */
 105         protected $mLastModified = '';
 106
 107         /** @var array */
 108         protected $mCategoryLinks = [];
 109
 110         /** @var array */
 111         protected $mCategories = [
 112                 'hidden' => [],
 113                 'normal' => [],
 114         ];
 115
 116         /** @var array */
 117         protected $mIndicators = [];
 118
 119         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 120         private $mLanguageLinks = [];
 121
 122         /**
 123          * Used for JavaScript (predates ResourceLoader)
 124          * @todo We should split JS / CSS.
 125          * mScripts content is inserted as is in "<head>" by Skin. This might
 126          * contain either a link to a stylesheet or inline CSS.
 127          */
 128         private $mScripts = '';
 129
 130         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 131         protected $mInlineStyles = '';
 132
 133         /**
 134          * @var string Used by skin template.
 135          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 136          */
 137         public $mPageLinkTitle = '';
 138
 139         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 140         protected $mHeadItems = [];
 141
 142         /** @var array */
 143         protected $mModules = [];
 144
 145         /** @var array */
 146         protected $mModuleScripts = [];
 147
 148         /** @var array */
 149         protected $mModuleStyles = [];
 150
 151         /** @var ResourceLoader */
 152         protected $mResourceLoader;
 153
 154         /** @var ResourceLoaderClientHtml */
 155         private $rlClient;
 156
 157         /** @var ResourceLoaderContext */
 158         private $rlClientContext;
 159
 160         /** @var string */
 161         private $rlUserModuleState;
 162
 163         /** @var array */
 164         private $rlExemptStyleModules;
 165
 166         /** @var array */
 167         protected $mJsConfigVars = [];
 168
 169         /** @var array */
 170         protected $mTemplateIds = [];
 171
 172         /** @var array */
 173         protected $mImageTimeKeys = [];
 174
 175         /** @var string */
 176         public $mRedirectCode = '';
 177
 178         protected $mFeedLinksAppendQuery = null;
 179
 180         /** @var array
 181          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 182          * @see ResourceLoaderModule::$origin
 183          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 184          */
 185         protected $mAllowedModules = [
 186                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 187         ];
 188
 189         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 190         protected $mDoNothing = false;
 191
 192         // Parser related.
 193
 194         /** @var int */
 195         protected $mContainsNewMagic = 0;
 196
 197         /**
 198          * lazy initialised, use parserOptions()
 199          * @var ParserOptions
 200          */
 201         protected $mParserOptions = null;
 202
 203         /**
 204          * Handles the Atom / RSS links.
 205          * We probably only support Atom in 2011.
 206          * @see $wgAdvertisedFeedTypes
 207          */
 208         private $mFeedLinks = [];
 209
 210         // Gwicke work on squid caching? Roughly from 2003.
 211         protected $mEnableClientCache = true;
 212
 213         /** @var bool Flag if output should only contain the body of the article. */
 214         private $mArticleBodyOnly = false;
 215
 216         /** @var bool */
 217         protected $mNewSectionLink = false;
 218
 219         /** @var bool */
 220         protected $mHideNewSectionLink = false;
 221
 222         /**
 223          * @var bool Comes from the parser. This was probably made to load CSS/JS
 224          * only if we had "<gallery>". Used directly in CategoryPage.php.
 225          * Looks like ResourceLoader can replace this.
 226          */
 227         public $mNoGallery = false;
 228
 229         /** @var string */
 230         private $mPageTitleActionText = '';
 231
 232         /** @var int Cache stuff. Looks like mEnableClientCache */
 233         protected $mCdnMaxage = 0;
 234         /** @var int Upper limit on mCdnMaxage */
 235         protected $mCdnMaxageLimit = INF;
 236
 237         /**
 238          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 239          * be sent. This should be done for pages where edit actions are possible.
 240          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 241          */
 242         protected $mPreventClickjacking = true;
 243
 244         /** @var int To include the variable {{REVISIONID}} */
 245         private $mRevisionId = null;
 246
 247         /** @var string */
 248         private $mRevisionTimestamp = null;
 249
 250         /** @var array */
 251         protected $mFileVersion = null;
 252
 253         /**
 254          * @var array An array of stylesheet filenames (relative from skins path),
 255          * with options for CSS media, IE conditions, and RTL/LTR direction.
 256          * For internal use; add settings in the skin via $this->addStyle()
 257          *
 258          * Style again! This seems like a code duplication since we already have
 259          * mStyles. This is what makes Open Source amazing.
 260          */
 261         protected $styles = [];
 262
 263         private $mIndexPolicy = 'index';
 264         private $mFollowPolicy = 'follow';
 265         private $mVaryHeader = [
 266                 'Accept-Encoding' => [ 'match=gzip' ],
 267         ];
 268
 269         /**
 270          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 271          * of the redirect.
 272          *
 273          * @var Title
 274          */
 275         private $mRedirectedFrom = null;
 276
 277         /**
 278          * Additional key => value data
 279          */
 280         private $mProperties = [];
 281
 282         /**
 283          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 284          */
 285         private $mTarget = null;
 286
 287         /**
 288          * @var bool Whether parser output should contain table of contents
 289          */
 290         private $mEnableTOC = true;
 291
 292         /**
 293          * @var bool Whether parser output should contain section edit links
 294          */
 295         private $mEnableSectionEditLinks = true;
 296
 297         /**
 298          * @var string|null The URL to send in a <link> element with rel=copyright
 299          */
 300         private $copyrightUrl;
 301
 302         /** @var array Profiling data */
 303         private $limitReportJSData = [];
 304
 305         /**
 306          * Link: header contents
 307          */
 308         private $mLinkHeader = [];
 309
 310         /**
 311          * Constructor for OutputPage. This should not be called directly.
 312          * Instead a new RequestContext should be created and it will implicitly create
 313          * a OutputPage tied to that context.
 314          * @param IContextSource|null $context
 315          */
 316         function __construct( IContextSource $context = null ) {
 317                 if ( $context === null ) {
 318                         # Extensions should use `new RequestContext` instead of `new OutputPage` now.
 319                         wfDeprecated( __METHOD__, '1.18' );
 320                 } else {
 321                         $this->setContext( $context );
 322                 }
 323         }
 324
 325         /**
 326          * Redirect to $url rather than displaying the normal page
 327          *
 328          * @param string $url URL
 329          * @param string $responsecode HTTP status code
 330          */
 331         public function redirect( $url, $responsecode = '302' ) {
 332                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 333                 $this->mRedirect = str_replace( "\n", '', $url );
 334                 $this->mRedirectCode = $responsecode;
 335         }
 336
 337         /**
 338          * Get the URL to redirect to, or an empty string if not redirect URL set
 339          *
 340          * @return string
 341          */
 342         public function getRedirect() {
 343                 return $this->mRedirect;
 344         }
 345
 346         /**
 347          * Set the copyright URL to send with the output.
 348          * Empty string to omit, null to reset.
 349          *
 350          * @since 1.26
 351          *
 352          * @param string|null $url
 353          */
 354         public function setCopyrightUrl( $url ) {
 355                 $this->copyrightUrl = $url;
 356         }
 357
 358         /**
 359          * Set the HTTP status code to send with the output.
 360          *
 361          * @param int $statusCode
 362          */
 363         public function setStatusCode( $statusCode ) {
 364                 $this->mStatusCode = $statusCode;
 365         }
 366
 367         /**
 368          * Add a new "<meta>" tag
 369          * To add an http-equiv meta tag, precede the name with "http:"
 370          *
 371          * @param string $name Tag name
 372          * @param string $val Tag value
 373          */
 374         function addMeta( $name, $val ) {
 375                 array_push( $this->mMetatags, [ $name, $val ] );
 376         }
 377
 378         /**
 379          * Returns the current <meta> tags
 380          *
 381          * @since 1.25
 382          * @return array
 383          */
 384         public function getMetaTags() {
 385                 return $this->mMetatags;
 386         }
 387
 388         /**
 389          * Add a new \<link\> tag to the page header.
 390          *
 391          * Note: use setCanonicalUrl() for rel=canonical.
 392          *
 393          * @param array $linkarr Associative array of attributes.
 394          */
 395         function addLink( array $linkarr ) {
 396                 array_push( $this->mLinktags, $linkarr );
 397         }
 398
 399         /**
 400          * Returns the current <link> tags
 401          *
 402          * @since 1.25
 403          * @return array
 404          */
 405         public function getLinkTags() {
 406                 return $this->mLinktags;
 407         }
 408
 409         /**
 410          * Add a new \<link\> with "rel" attribute set to "meta"
 411          *
 412          * @param array $linkarr Associative array mapping attribute names to their
 413          *                 values, both keys and values will be escaped, and the
 414          *                 "rel" attribute will be automatically added
 415          */
 416         function addMetadataLink( array $linkarr ) {
 417                 $linkarr['rel'] = $this->getMetadataAttribute();
 418                 $this->addLink( $linkarr );
 419         }
 420
 421         /**
 422          * Set the URL to be used for the <link rel=canonical>. This should be used
 423          * in preference to addLink(), to avoid duplicate link tags.
 424          * @param string $url
 425          */
 426         function setCanonicalUrl( $url ) {
 427                 $this->mCanonicalUrl = $url;
 428         }
 429
 430         /**
 431          * Returns the URL to be used for the <link rel=canonical> if
 432          * one is set.
 433          *
 434          * @since 1.25
 435          * @return bool|string
 436          */
 437         public function getCanonicalUrl() {
 438                 return $this->mCanonicalUrl;
 439         }
 440
 441         /**
 442          * Get the value of the "rel" attribute for metadata links
 443          *
 444          * @return string
 445          */
 446         public function getMetadataAttribute() {
 447                 # note: buggy CC software only reads first "meta" link
 448                 static $haveMeta = false;
 449                 if ( $haveMeta ) {
 450                         return 'alternate meta';
 451                 } else {
 452                         $haveMeta = true;
 453                         return 'meta';
 454                 }
 455         }
 456
 457         /**
 458          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 459          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 460          * if possible.
 461          *
 462          * @param string $script Raw HTML
 463          */
 464         function addScript( $script ) {
 465                 $this->mScripts .= $script;
 466         }
 467
 468         /**
 469          * Register and add a stylesheet from an extension directory.
 470          *
 471          * @deprecated since 1.27 use addModuleStyles() or addStyle() instead
 472          * @param string $url Path to sheet.  Provide either a full url (beginning
 473          *             with 'http', etc) or a relative path from the document root
 474          *             (beginning with '/').  Otherwise it behaves identically to
 475          *             addStyle() and draws from the /skins folder.
 476          */
 477         public function addExtensionStyle( $url ) {
 478                 wfDeprecated( __METHOD__, '1.27' );
 479                 array_push( $this->mExtStyles, $url );
 480         }
 481
 482         /**
 483          * Get all styles added by extensions
 484          *
 485          * @deprecated since 1.27
 486          * @return array
 487          */
 488         function getExtStyle() {
 489                 wfDeprecated( __METHOD__, '1.27' );
 490                 return $this->mExtStyles;
 491         }
 492
 493         /**
 494          * Add a JavaScript file out of skins/common, or a given relative path.
 495          * Internal use only. Use OutputPage::addModules() if possible.
 496          *
 497          * @param string $file Filename in skins/common or complete on-server path
 498          *              (/foo/bar.js)
 499          * @param string $version Style version of the file. Defaults to $wgStyleVersion
 500          */
 501         public function addScriptFile( $file, $version = null ) {
 502                 // See if $file parameter is an absolute URL or begins with a slash
 503                 if ( substr( $file, 0, 1 ) == '/' || preg_match( '#^[a-z]*://#i', $file ) ) {
 504                         $path = $file;
 505                 } else {
 506                         $path = $this->getConfig()->get( 'StylePath' ) . "/common/{$file}";
 507                 }
 508                 if ( is_null( $version ) ) {
 509                         $version = $this->getConfig()->get( 'StyleVersion' );
 510                 }
 511                 $this->addScript( Html::linkedScript( wfAppendQuery( $path, $version ) ) );
 512         }
 513
 514         /**
 515          * Add a self-contained script tag with the given contents
 516          * Internal use only. Use OutputPage::addModules() if possible.
 517          *
 518          * @param string $script JavaScript text, no script tags
 519          */
 520         public function addInlineScript( $script ) {
 521                 $this->mScripts .= Html::inlineScript( $script );
 522         }
 523
 524         /**
 525          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 526          * which are no longer registered (eg a page is cached before an extension is disabled)
 527          * @param array $modules
 528          * @param string|null $position If not null, only return modules with this position
 529          * @param string $type
 530          * @return array
 531          */
 532         protected function filterModules( array $modules, $position = null,
 533                 $type = ResourceLoaderModule::TYPE_COMBINED
 534         ) {
 535                 $resourceLoader = $this->getResourceLoader();
 536                 $filteredModules = [];
 537                 foreach ( $modules as $val ) {
 538                         $module = $resourceLoader->getModule( $val );
 539                         if ( $module instanceof ResourceLoaderModule
 540                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 541                                 && ( is_null( $position ) || $module->getPosition() == $position )
 542                         ) {
 543                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 544                                         $this->warnModuleTargetFilter( $module->getName() );
 545                                         continue;
 546                                 }
 547                                 $filteredModules[] = $val;
 548                         }
 549                 }
 550                 return $filteredModules;
 551         }
 552
 553         private function warnModuleTargetFilter( $moduleName ) {
 554                 static $warnings = [];
 555                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 556                         return;
 557                 }
 558                 $warnings[$this->mTarget][$moduleName] = true;
 559                 $this->getResourceLoader()->getLogger()->debug(
 560                         'Module "{module}" not loadable on target "{target}".',
 561                         [
 562                                 'module' => $moduleName,
 563                                 'target' => $this->mTarget,
 564                         ]
 565                 );
 566         }
 567
 568         /**
 569          * Get the list of modules to include on this page
 570          *
 571          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 572          * @param string|null $position If not null, only return modules with this position
 573          * @param string $param
 574          * @return array Array of module names
 575          */
 576         public function getModules( $filter = false, $position = null, $param = 'mModules',
 577                 $type = ResourceLoaderModule::TYPE_COMBINED
 578         ) {
 579                 $modules = array_values( array_unique( $this->$param ) );
 580                 return $filter
 581                         ? $this->filterModules( $modules, $position, $type )
 582                         : $modules;
 583         }
 584
 585         /**
 586          * Add one or more modules recognized by ResourceLoader. Modules added
 587          * through this function will be loaded by ResourceLoader when the
 588          * page loads.
 589          *
 590          * @param string|array $modules Module name (string) or array of module names
 591          */
 592         public function addModules( $modules ) {
 593                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 594         }
 595
 596         /**
 597          * Get the list of module JS to include on this page
 598          *
 599          * @param bool $filter
 600          * @param string|null $position
 601          * @return array Array of module names
 602          */
 603         public function getModuleScripts( $filter = false, $position = null ) {
 604                 return $this->getModules( $filter, $position, 'mModuleScripts',
 605                         ResourceLoaderModule::TYPE_SCRIPTS
 606                 );
 607         }
 608
 609         /**
 610          * Add only JS of one or more modules recognized by ResourceLoader. Module
 611          * scripts added through this function will be loaded by ResourceLoader when
 612          * the page loads.
 613          *
 614          * @param string|array $modules Module name (string) or array of module names
 615          */
 616         public function addModuleScripts( $modules ) {
 617                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 618         }
 619
 620         /**
 621          * Get the list of module CSS to include on this page
 622          *
 623          * @param bool $filter
 624          * @param string|null $position
 625          * @return array Array of module names
 626          */
 627         public function getModuleStyles( $filter = false, $position = null ) {
 628                 return $this->getModules( $filter, $position, 'mModuleStyles',
 629                         ResourceLoaderModule::TYPE_STYLES
 630                 );
 631         }
 632
 633         /**
 634          * Add only CSS of one or more modules recognized by ResourceLoader.
 635          *
 636          * Module styles added through this function will be added using standard link CSS
 637          * tags, rather than as a combined Javascript and CSS package. Thus, they will
 638          * load when JavaScript is disabled (unless CSS also happens to be disabled).
 639          *
 640          * @param string|array $modules Module name (string) or array of module names
 641          */
 642         public function addModuleStyles( $modules ) {
 643                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 644         }
 645
 646         /**
 647          * @return null|string ResourceLoader target
 648          */
 649         public function getTarget() {
 650                 return $this->mTarget;
 651         }
 652
 653         /**
 654          * Sets ResourceLoader target for load.php links. If null, will be omitted
 655          *
 656          * @param string|null $target
 657          */
 658         public function setTarget( $target ) {
 659                 $this->mTarget = $target;
 660         }
 661
 662         /**
 663          * Get an array of head items
 664          *
 665          * @return array
 666          */
 667         function getHeadItemsArray() {
 668                 return $this->mHeadItems;
 669         }
 670
 671         /**
 672          * Add or replace a head item to the output
 673          *
 674          * Whenever possible, use more specific options like ResourceLoader modules,
 675          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 676          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 677          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 678          * This would be your very LAST fallback.
 679          *
 680          * @param string $name Item name
 681          * @param string $value Raw HTML
 682          */
 683         public function addHeadItem( $name, $value ) {
 684                 $this->mHeadItems[$name] = $value;
 685         }
 686
 687         /**
 688          * Add one or more head items to the output
 689          *
 690          * @since 1.28
 691          * @param string|string[] $value Raw HTML
 692          */
 693         public function addHeadItems( $values ) {
 694                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 695         }
 696
 697         /**
 698          * Check if the header item $name is already set
 699          *
 700          * @param string $name Item name
 701          * @return bool
 702          */
 703         public function hasHeadItem( $name ) {
 704                 return isset( $this->mHeadItems[$name] );
 705         }
 706
 707         /**
 708          * @deprecated since 1.28 Obsolete - wgUseETag experiment was removed.
 709          * @param string $tag
 710          */
 711         public function setETag( $tag ) {
 712         }
 713
 714         /**
 715          * Set whether the output should only contain the body of the article,
 716          * without any skin, sidebar, etc.
 717          * Used e.g. when calling with "action=render".
 718          *
 719          * @param bool $only Whether to output only the body of the article
 720          */
 721         public function setArticleBodyOnly( $only ) {
 722                 $this->mArticleBodyOnly = $only;
 723         }
 724
 725         /**
 726          * Return whether the output will contain only the body of the article
 727          *
 728          * @return bool
 729          */
 730         public function getArticleBodyOnly() {
 731                 return $this->mArticleBodyOnly;
 732         }
 733
 734         /**
 735          * Set an additional output property
 736          * @since 1.21
 737          *
 738          * @param string $name
 739          * @param mixed $value
 740          */
 741         public function setProperty( $name, $value ) {
 742                 $this->mProperties[$name] = $value;
 743         }
 744
 745         /**
 746          * Get an additional output property
 747          * @since 1.21
 748          *
 749          * @param string $name
 750          * @return mixed Property value or null if not found
 751          */
 752         public function getProperty( $name ) {
 753                 if ( isset( $this->mProperties[$name] ) ) {
 754                         return $this->mProperties[$name];
 755                 } else {
 756                         return null;
 757                 }
 758         }
 759
 760         /**
 761          * checkLastModified tells the client to use the client-cached page if
 762          * possible. If successful, the OutputPage is disabled so that
 763          * any future call to OutputPage->output() have no effect.
 764          *
 765          * Side effect: sets mLastModified for Last-Modified header
 766          *
 767          * @param string $timestamp
 768          *
 769          * @return bool True if cache-ok headers was sent.
 770          */
 771         public function checkLastModified( $timestamp ) {
 772                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 773                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 774                         return false;
 775                 }
 776                 $config = $this->getConfig();
 777                 if ( !$config->get( 'CachePages' ) ) {
 778                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 779                         return false;
 780                 }
 781
 782                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 783                 $modifiedTimes = [
 784                         'page' => $timestamp,
 785                         'user' => $this->getUser()->getTouched(),
 786                         'epoch' => $config->get( 'CacheEpoch' )
 787                 ];
 788                 if ( $config->get( 'UseSquid' ) ) {
 789                         // T46570: the core page itself may not change, but resources might
 790                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, time() - $config->get( 'SquidMaxage' ) );
 791                 }
 792                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 793
 794                 $maxModified = max( $modifiedTimes );
 795                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 796
 797                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 798                 if ( $clientHeader === false ) {
 799                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 800                         return false;
 801                 }
 802
 803                 # IE sends sizes after the date like this:
 804                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 805                 # this breaks strtotime().
 806                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 807
 808                 MediaWiki\suppressWarnings(); // E_STRICT system time bitching
 809                 $clientHeaderTime = strtotime( $clientHeader );
 810                 MediaWiki\restoreWarnings();
 811                 if ( !$clientHeaderTime ) {
 812                         wfDebug( __METHOD__
 813                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 814                         return false;
 815                 }
 816                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 817
 818                 # Make debug info
 819                 $info = '';
 820                 foreach ( $modifiedTimes as $name => $value ) {
 821                         if ( $info !== '' ) {
 822                                 $info .= ', ';
 823                         }
 824                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 825                 }
 826
 827                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 828                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 829                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 830                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 831                 if ( $clientHeaderTime < $maxModified ) {
 832                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 833                         return false;
 834                 }
 835
 836                 # Not modified
 837                 # Give a 304 Not Modified response code and disable body output
 838                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 839                 ini_set( 'zlib.output_compression', 0 );
 840                 $this->getRequest()->response()->statusHeader( 304 );
 841                 $this->sendCacheControl();
 842                 $this->disable();
 843
 844                 // Don't output a compressed blob when using ob_gzhandler;
 845                 // it's technically against HTTP spec and seems to confuse
 846                 // Firefox when the response gets split over two packets.
 847                 wfClearOutputBuffers();
 848
 849                 return true;
 850         }
 851
 852         /**
 853          * Override the last modified timestamp
 854          *
 855          * @param string $timestamp New timestamp, in a format readable by
 856          *        wfTimestamp()
 857          */
 858         public function setLastModified( $timestamp ) {
 859                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 860         }
 861
 862         /**
 863          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 864          *
 865          * @param string $policy The literal string to output as the contents of
 866          *   the meta tag.  Will be parsed according to the spec and output in
 867          *   standardized form.
 868          * @return null
 869          */
 870         public function setRobotPolicy( $policy ) {
 871                 $policy = Article::formatRobotPolicy( $policy );
 872
 873                 if ( isset( $policy['index'] ) ) {
 874                         $this->setIndexPolicy( $policy['index'] );
 875                 }
 876                 if ( isset( $policy['follow'] ) ) {
 877                         $this->setFollowPolicy( $policy['follow'] );
 878                 }
 879         }
 880
 881         /**
 882          * Set the index policy for the page, but leave the follow policy un-
 883          * touched.
 884          *
 885          * @param string $policy Either 'index' or 'noindex'.
 886          * @return null
 887          */
 888         public function setIndexPolicy( $policy ) {
 889                 $policy = trim( $policy );
 890                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 891                         $this->mIndexPolicy = $policy;
 892                 }
 893         }
 894
 895         /**
 896          * Set the follow policy for the page, but leave the index policy un-
 897          * touched.
 898          *
 899          * @param string $policy Either 'follow' or 'nofollow'.
 900          * @return null
 901          */
 902         public function setFollowPolicy( $policy ) {
 903                 $policy = trim( $policy );
 904                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 905                         $this->mFollowPolicy = $policy;
 906                 }
 907         }
 908
 909         /**
 910          * Set the new value of the "action text", this will be added to the
 911          * "HTML title", separated from it with " - ".
 912          *
 913          * @param string $text New value of the "action text"
 914          */
 915         public function setPageTitleActionText( $text ) {
 916                 $this->mPageTitleActionText = $text;
 917         }
 918
 919         /**
 920          * Get the value of the "action text"
 921          *
 922          * @return string
 923          */
 924         public function getPageTitleActionText() {
 925                 return $this->mPageTitleActionText;
 926         }
 927
 928         /**
 929          * "HTML title" means the contents of "<title>".
 930          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 931          *
 932          * @param string|Message $name
 933          */
 934         public function setHTMLTitle( $name ) {
 935                 if ( $name instanceof Message ) {
 936                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 937                 } else {
 938                         $this->mHTMLtitle = $name;
 939                 }
 940         }
 941
 942         /**
 943          * Return the "HTML title", i.e. the content of the "<title>" tag.
 944          *
 945          * @return string
 946          */
 947         public function getHTMLTitle() {
 948                 return $this->mHTMLtitle;
 949         }
 950
 951         /**
 952          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 953          *
 954          * @param Title $t
 955          */
 956         public function setRedirectedFrom( $t ) {
 957                 $this->mRedirectedFrom = $t;
 958         }
 959
 960         /**
 961          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 962          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 963          * but not bad tags like \<script\>. This function automatically sets
 964          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 965          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 966          * good tags like \<i\> will be dropped entirely.
 967          *
 968          * @param string|Message $name
 969          */
 970         public function setPageTitle( $name ) {
 971                 if ( $name instanceof Message ) {
 972                         $name = $name->setContext( $this->getContext() )->text();
 973                 }
 974
 975                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 976                 # but leave "<i>foobar</i>" alone
 977                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 978                 $this->mPagetitle = $nameWithTags;
 979
 980                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 981                 $this->setHTMLTitle(
 982                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 983                                 ->inContentLanguage()
 984                 );
 985         }
 986
 987         /**
 988          * Return the "page title", i.e. the content of the \<h1\> tag.
 989          *
 990          * @return string
 991          */
 992         public function getPageTitle() {
 993                 return $this->mPagetitle;
 994         }
 995
 996         /**
 997          * Set the Title object to use
 998          *
 999          * @param Title $t
1000          */
1001         public function setTitle( Title $t ) {
1002                 $this->getContext()->setTitle( $t );
1003         }
1004
1005         /**
1006          * Replace the subtitle with $str
1007          *
1008          * @param string|Message $str New value of the subtitle. String should be safe HTML.
1009          */
1010         public function setSubtitle( $str ) {
1011                 $this->clearSubtitle();
1012                 $this->addSubtitle( $str );
1013         }
1014
1015         /**
1016          * Add $str to the subtitle
1017          *
1018          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
1019          */
1020         public function addSubtitle( $str ) {
1021                 if ( $str instanceof Message ) {
1022                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
1023                 } else {
1024                         $this->mSubtitle[] = $str;
1025                 }
1026         }
1027
1028         /**
1029          * Build message object for a subtitle containing a backlink to a page
1030          *
1031          * @param Title $title Title to link to
1032          * @param array $query Array of additional parameters to include in the link
1033          * @return Message
1034          * @since 1.25
1035          */
1036         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1037                 if ( $title->isRedirect() ) {
1038                         $query['redirect'] = 'no';
1039                 }
1040                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1041                 return wfMessage( 'backlinksubtitle' )
1042                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1043         }
1044
1045         /**
1046          * Add a subtitle containing a backlink to a page
1047          *
1048          * @param Title $title Title to link to
1049          * @param array $query Array of additional parameters to include in the link
1050          */
1051         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1052                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1053         }
1054
1055         /**
1056          * Clear the subtitles
1057          */
1058         public function clearSubtitle() {
1059                 $this->mSubtitle = [];
1060         }
1061
1062         /**
1063          * Get the subtitle
1064          *
1065          * @return string
1066          */
1067         public function getSubtitle() {
1068                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1069         }
1070
1071         /**
1072          * Set the page as printable, i.e. it'll be displayed with all
1073          * print styles included
1074          */
1075         public function setPrintable() {
1076                 $this->mPrintable = true;
1077         }
1078
1079         /**
1080          * Return whether the page is "printable"
1081          *
1082          * @return bool
1083          */
1084         public function isPrintable() {
1085                 return $this->mPrintable;
1086         }
1087
1088         /**
1089          * Disable output completely, i.e. calling output() will have no effect
1090          */
1091         public function disable() {
1092                 $this->mDoNothing = true;
1093         }
1094
1095         /**
1096          * Return whether the output will be completely disabled
1097          *
1098          * @return bool
1099          */
1100         public function isDisabled() {
1101                 return $this->mDoNothing;
1102         }
1103
1104         /**
1105          * Show an "add new section" link?
1106          *
1107          * @return bool
1108          */
1109         public function showNewSectionLink() {
1110                 return $this->mNewSectionLink;
1111         }
1112
1113         /**
1114          * Forcibly hide the new section link?
1115          *
1116          * @return bool
1117          */
1118         public function forceHideNewSectionLink() {
1119                 return $this->mHideNewSectionLink;
1120         }
1121
1122         /**
1123          * Add or remove feed links in the page header
1124          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1125          * for the new version
1126          * @see addFeedLink()
1127          *
1128          * @param bool $show True: add default feeds, false: remove all feeds
1129          */
1130         public function setSyndicated( $show = true ) {
1131                 if ( $show ) {
1132                         $this->setFeedAppendQuery( false );
1133                 } else {
1134                         $this->mFeedLinks = [];
1135                 }
1136         }
1137
1138         /**
1139          * Add default feeds to the page header
1140          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1141          * for the new version
1142          * @see addFeedLink()
1143          *
1144          * @param string $val Query to append to feed links or false to output
1145          *        default links
1146          */
1147         public function setFeedAppendQuery( $val ) {
1148                 $this->mFeedLinks = [];
1149
1150                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1151                         $query = "feed=$type";
1152                         if ( is_string( $val ) ) {
1153                                 $query .= '&' . $val;
1154                         }
1155                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1156                 }
1157         }
1158
1159         /**
1160          * Add a feed link to the page header
1161          *
1162          * @param string $format Feed type, should be a key of $wgFeedClasses
1163          * @param string $href URL
1164          */
1165         public function addFeedLink( $format, $href ) {
1166                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1167                         $this->mFeedLinks[$format] = $href;
1168                 }
1169         }
1170
1171         /**
1172          * Should we output feed links for this page?
1173          * @return bool
1174          */
1175         public function isSyndicated() {
1176                 return count( $this->mFeedLinks ) > 0;
1177         }
1178
1179         /**
1180          * Return URLs for each supported syndication format for this page.
1181          * @return array Associating format keys with URLs
1182          */
1183         public function getSyndicationLinks() {
1184                 return $this->mFeedLinks;
1185         }
1186
1187         /**
1188          * Will currently always return null
1189          *
1190          * @return null
1191          */
1192         public function getFeedAppendQuery() {
1193                 return $this->mFeedLinksAppendQuery;
1194         }
1195
1196         /**
1197          * Set whether the displayed content is related to the source of the
1198          * corresponding article on the wiki
1199          * Setting true will cause the change "article related" toggle to true
1200          *
1201          * @param bool $v
1202          */
1203         public function setArticleFlag( $v ) {
1204                 $this->mIsarticle = $v;
1205                 if ( $v ) {
1206                         $this->mIsArticleRelated = $v;
1207                 }
1208         }
1209
1210         /**
1211          * Return whether the content displayed page is related to the source of
1212          * the corresponding article on the wiki
1213          *
1214          * @return bool
1215          */
1216         public function isArticle() {
1217                 return $this->mIsarticle;
1218         }
1219
1220         /**
1221          * Set whether this page is related an article on the wiki
1222          * Setting false will cause the change of "article flag" toggle to false
1223          *
1224          * @param bool $v
1225          */
1226         public function setArticleRelated( $v ) {
1227                 $this->mIsArticleRelated = $v;
1228                 if ( !$v ) {
1229                         $this->mIsarticle = false;
1230                 }
1231         }
1232
1233         /**
1234          * Return whether this page is related an article on the wiki
1235          *
1236          * @return bool
1237          */
1238         public function isArticleRelated() {
1239                 return $this->mIsArticleRelated;
1240         }
1241
1242         /**
1243          * Add new language links
1244          *
1245          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1246          *                               (e.g. 'fr:Test page')
1247          */
1248         public function addLanguageLinks( array $newLinkArray ) {
1249                 $this->mLanguageLinks += $newLinkArray;
1250         }
1251
1252         /**
1253          * Reset the language links and add new language links
1254          *
1255          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1256          *                               (e.g. 'fr:Test page')
1257          */
1258         public function setLanguageLinks( array $newLinkArray ) {
1259                 $this->mLanguageLinks = $newLinkArray;
1260         }
1261
1262         /**
1263          * Get the list of language links
1264          *
1265          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1266          */
1267         public function getLanguageLinks() {
1268                 return $this->mLanguageLinks;
1269         }
1270
1271         /**
1272          * Add an array of categories, with names in the keys
1273          *
1274          * @param array $categories Mapping category name => sort key
1275          */
1276         public function addCategoryLinks( array $categories ) {
1277                 global $wgContLang;
1278
1279                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1280                         return;
1281                 }
1282
1283                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1284
1285                 # Set all the values to 'normal'.
1286                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1287
1288                 # Mark hidden categories
1289                 foreach ( $res as $row ) {
1290                         if ( isset( $row->pp_value ) ) {
1291                                 $categories[$row->page_title] = 'hidden';
1292                         }
1293                 }
1294
1295                 // Avoid PHP 7.1 warning of passing $this by reference
1296                 $outputPage = $this;
1297                 # Add the remaining categories to the skin
1298                 if ( Hooks::run(
1299                         'OutputPageMakeCategoryLinks',
1300                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1301                 ) {
1302                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1303                         foreach ( $categories as $category => $type ) {
1304                                 // array keys will cast numeric category names to ints, so cast back to string
1305                                 $category = (string)$category;
1306                                 $origcategory = $category;
1307                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1308                                 if ( !$title ) {
1309                                         continue;
1310                                 }
1311                                 $wgContLang->findVariantLink( $category, $title, true );
1312                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1313                                         continue;
1314                                 }
1315                                 $text = $wgContLang->convertHtml( $title->getText() );
1316                                 $this->mCategories[$type][] = $title->getText();
1317                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1318                         }
1319                 }
1320         }
1321
1322         /**
1323          * @param array $categories
1324          * @return bool|ResultWrapper
1325          */
1326         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1327                 # Add the links to a LinkBatch
1328                 $arr = [ NS_CATEGORY => $categories ];
1329                 $lb = new LinkBatch;
1330                 $lb->setArray( $arr );
1331
1332                 # Fetch existence plus the hiddencat property
1333                 $dbr = wfGetDB( DB_REPLICA );
1334                 $fields = array_merge(
1335                         LinkCache::getSelectFields(),
1336                         [ 'page_namespace', 'page_title', 'pp_value' ]
1337                 );
1338
1339                 $res = $dbr->select( [ 'page', 'page_props' ],
1340                         $fields,
1341                         $lb->constructSet( 'page', $dbr ),
1342                         __METHOD__,
1343                         [],
1344                         [ 'page_props' => [ 'LEFT JOIN', [
1345                                 'pp_propname' => 'hiddencat',
1346                                 'pp_page = page_id'
1347                         ] ] ]
1348                 );
1349
1350                 # Add the results to the link cache
1351                 $lb->addResultToCache( LinkCache::singleton(), $res );
1352
1353                 return $res;
1354         }
1355
1356         /**
1357          * Reset the category links (but not the category list) and add $categories
1358          *
1359          * @param array $categories Mapping category name => sort key
1360          */
1361         public function setCategoryLinks( array $categories ) {
1362                 $this->mCategoryLinks = [];
1363                 $this->addCategoryLinks( $categories );
1364         }
1365
1366         /**
1367          * Get the list of category links, in a 2-D array with the following format:
1368          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1369          * hidden categories) and $link a HTML fragment with a link to the category
1370          * page
1371          *
1372          * @return array
1373          */
1374         public function getCategoryLinks() {
1375                 return $this->mCategoryLinks;
1376         }
1377
1378         /**
1379          * Get the list of category names this page belongs to.
1380          *
1381          * @param string $type The type of categories which should be returned. Possible values:
1382          *  * all: all categories of all types
1383          *  * hidden: only the hidden categories
1384          *  * normal: all categories, except hidden categories
1385          * @return array Array of strings
1386          */
1387         public function getCategories( $type = 'all' ) {
1388                 if ( $type === 'all' ) {
1389                         $allCategories = [];
1390                         foreach ( $this->mCategories as $categories ) {
1391                                 $allCategories = array_merge( $allCategories, $categories );
1392                         }
1393                         return $allCategories;
1394                 }
1395                 if ( !isset( $this->mCategories[$type] ) ) {
1396                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1397                 }
1398                 return $this->mCategories[$type];
1399         }
1400
1401         /**
1402          * Add an array of indicators, with their identifiers as array
1403          * keys and HTML contents as values.
1404          *
1405          * In case of duplicate keys, existing values are overwritten.
1406          *
1407          * @param array $indicators
1408          * @since 1.25
1409          */
1410         public function setIndicators( array $indicators ) {
1411                 $this->mIndicators = $indicators + $this->mIndicators;
1412                 // Keep ordered by key
1413                 ksort( $this->mIndicators );
1414         }
1415
1416         /**
1417          * Get the indicators associated with this page.
1418          *
1419          * The array will be internally ordered by item keys.
1420          *
1421          * @return array Keys: identifiers, values: HTML contents
1422          * @since 1.25
1423          */
1424         public function getIndicators() {
1425                 return $this->mIndicators;
1426         }
1427
1428         /**
1429          * Adds help link with an icon via page indicators.
1430          * Link target can be overridden by a local message containing a wikilink:
1431          * the message key is: lowercase action or special page name + '-helppage'.
1432          * @param string $to Target MediaWiki.org page title or encoded URL.
1433          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1434          * @since 1.25
1435          */
1436         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1437                 $this->addModuleStyles( 'mediawiki.helplink' );
1438                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1439
1440                 if ( $overrideBaseUrl ) {
1441                         $helpUrl = $to;
1442                 } else {
1443                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1444                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1445                 }
1446
1447                 $link = Html::rawElement(
1448                         'a',
1449                         [
1450                                 'href' => $helpUrl,
1451                                 'target' => '_blank',
1452                                 'class' => 'mw-helplink',
1453                         ],
1454                         $text
1455                 );
1456
1457                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1458         }
1459
1460         /**
1461          * Do not allow scripts which can be modified by wiki users to load on this page;
1462          * only allow scripts bundled with, or generated by, the software.
1463          * Site-wide styles are controlled by a config setting, since they can be
1464          * used to create a custom skin/theme, but not user-specific ones.
1465          *
1466          * @todo this should be given a more accurate name
1467          */
1468         public function disallowUserJs() {
1469                 $this->reduceAllowedModules(
1470                         ResourceLoaderModule::TYPE_SCRIPTS,
1471                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1472                 );
1473
1474                 // Site-wide styles are controlled by a config setting, see T73621
1475                 // for background on why. User styles are never allowed.
1476                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1477                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1478                 } else {
1479                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1480                 }
1481                 $this->reduceAllowedModules(
1482                         ResourceLoaderModule::TYPE_STYLES,
1483                         $styleOrigin
1484                 );
1485         }
1486
1487         /**
1488          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1489          * @see ResourceLoaderModule::$origin
1490          * @param string $type ResourceLoaderModule TYPE_ constant
1491          * @return int ResourceLoaderModule ORIGIN_ class constant
1492          */
1493         public function getAllowedModules( $type ) {
1494                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1495                         return min( array_values( $this->mAllowedModules ) );
1496                 } else {
1497                         return isset( $this->mAllowedModules[$type] )
1498                                 ? $this->mAllowedModules[$type]
1499                                 : ResourceLoaderModule::ORIGIN_ALL;
1500                 }
1501         }
1502
1503         /**
1504          * Limit the highest level of CSS/JS untrustworthiness allowed.
1505          *
1506          * If passed the same or a higher level than the current level of untrustworthiness set, the
1507          * level will remain unchanged.
1508          *
1509          * @param string $type
1510          * @param int $level ResourceLoaderModule class constant
1511          */
1512         public function reduceAllowedModules( $type, $level ) {
1513                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1514         }
1515
1516         /**
1517          * Prepend $text to the body HTML
1518          *
1519          * @param string $text HTML
1520          */
1521         public function prependHTML( $text ) {
1522                 $this->mBodytext = $text . $this->mBodytext;
1523         }
1524
1525         /**
1526          * Append $text to the body HTML
1527          *
1528          * @param string $text HTML
1529          */
1530         public function addHTML( $text ) {
1531                 $this->mBodytext .= $text;
1532         }
1533
1534         /**
1535          * Shortcut for adding an Html::element via addHTML.
1536          *
1537          * @since 1.19
1538          *
1539          * @param string $element
1540          * @param array $attribs
1541          * @param string $contents
1542          */
1543         public function addElement( $element, array $attribs = [], $contents = '' ) {
1544                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1545         }
1546
1547         /**
1548          * Clear the body HTML
1549          */
1550         public function clearHTML() {
1551                 $this->mBodytext = '';
1552         }
1553
1554         /**
1555          * Get the body HTML
1556          *
1557          * @return string HTML
1558          */
1559         public function getHTML() {
1560                 return $this->mBodytext;
1561         }
1562
1563         /**
1564          * Get/set the ParserOptions object to use for wikitext parsing
1565          *
1566          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1567          *   current ParserOption object
1568          * @return ParserOptions
1569          */
1570         public function parserOptions( $options = null ) {
1571                 if ( $options !== null && !empty( $options->isBogus ) ) {
1572                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1573                         // been changed somehow, and keep it if so.
1574                         $anonPO = ParserOptions::newFromAnon();
1575                         $anonPO->setEditSection( false );
1576                         $anonPO->setAllowUnsafeRawHtml( false );
1577                         if ( !$options->matches( $anonPO ) ) {
1578                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1579                                 $options->isBogus = false;
1580                         }
1581                 }
1582
1583                 if ( !$this->mParserOptions ) {
1584                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1585                                 // $wgUser isn't unstubbable yet, so don't try to get a
1586                                 // ParserOptions for it. And don't cache this ParserOptions
1587                                 // either.
1588                                 $po = ParserOptions::newFromAnon();
1589                                 $po->setEditSection( false );
1590                                 $po->setAllowUnsafeRawHtml( false );
1591                                 $po->isBogus = true;
1592                                 if ( $options !== null ) {
1593                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1594                                 }
1595                                 return $po;
1596                         }
1597
1598                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1599                         $this->mParserOptions->setEditSection( false );
1600                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1601                 }
1602
1603                 if ( $options !== null && !empty( $options->isBogus ) ) {
1604                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1605                         // thing.
1606                         return wfSetVar( $this->mParserOptions, null, true );
1607                 } else {
1608                         return wfSetVar( $this->mParserOptions, $options );
1609                 }
1610         }
1611
1612         /**
1613          * Set the revision ID which will be seen by the wiki text parser
1614          * for things such as embedded {{REVISIONID}} variable use.
1615          *
1616          * @param int|null $revid An positive integer, or null
1617          * @return mixed Previous value
1618          */
1619         public function setRevisionId( $revid ) {
1620                 $val = is_null( $revid ) ? null : intval( $revid );
1621                 return wfSetVar( $this->mRevisionId, $val );
1622         }
1623
1624         /**
1625          * Get the displayed revision ID
1626          *
1627          * @return int
1628          */
1629         public function getRevisionId() {
1630                 return $this->mRevisionId;
1631         }
1632
1633         /**
1634          * Set the timestamp of the revision which will be displayed. This is used
1635          * to avoid a extra DB call in Skin::lastModified().
1636          *
1637          * @param string|null $timestamp
1638          * @return mixed Previous value
1639          */
1640         public function setRevisionTimestamp( $timestamp ) {
1641                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1642         }
1643
1644         /**
1645          * Get the timestamp of displayed revision.
1646          * This will be null if not filled by setRevisionTimestamp().
1647          *
1648          * @return string|null
1649          */
1650         public function getRevisionTimestamp() {
1651                 return $this->mRevisionTimestamp;
1652         }
1653
1654         /**
1655          * Set the displayed file version
1656          *
1657          * @param File|bool $file
1658          * @return mixed Previous value
1659          */
1660         public function setFileVersion( $file ) {
1661                 $val = null;
1662                 if ( $file instanceof File && $file->exists() ) {
1663                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1664                 }
1665                 return wfSetVar( $this->mFileVersion, $val, true );
1666         }
1667
1668         /**
1669          * Get the displayed file version
1670          *
1671          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1672          */
1673         public function getFileVersion() {
1674                 return $this->mFileVersion;
1675         }
1676
1677         /**
1678          * Get the templates used on this page
1679          *
1680          * @return array (namespace => dbKey => revId)
1681          * @since 1.18
1682          */
1683         public function getTemplateIds() {
1684                 return $this->mTemplateIds;
1685         }
1686
1687         /**
1688          * Get the files used on this page
1689          *
1690          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1691          * @since 1.18
1692          */
1693         public function getFileSearchOptions() {
1694                 return $this->mImageTimeKeys;
1695         }
1696
1697         /**
1698          * Convert wikitext to HTML and add it to the buffer
1699          * Default assumes that the current page title will be used.
1700          *
1701          * @param string $text
1702          * @param bool $linestart Is this the start of a line?
1703          * @param bool $interface Is this text in the user interface language?
1704          * @throws MWException
1705          */
1706         public function addWikiText( $text, $linestart = true, $interface = true ) {
1707                 $title = $this->getTitle(); // Work around E_STRICT
1708                 if ( !$title ) {
1709                         throw new MWException( 'Title is null' );
1710                 }
1711                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1712         }
1713
1714         /**
1715          * Add wikitext with a custom Title object
1716          *
1717          * @param string $text Wikitext
1718          * @param Title $title
1719          * @param bool $linestart Is this the start of a line?
1720          */
1721         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1722                 $this->addWikiTextTitle( $text, $title, $linestart );
1723         }
1724
1725         /**
1726          * Add wikitext with a custom Title object and tidy enabled.
1727          *
1728          * @param string $text Wikitext
1729          * @param Title $title
1730          * @param bool $linestart Is this the start of a line?
1731          */
1732         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1733                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1734         }
1735
1736         /**
1737          * Add wikitext with tidy enabled
1738          *
1739          * @param string $text Wikitext
1740          * @param bool $linestart Is this the start of a line?
1741          */
1742         public function addWikiTextTidy( $text, $linestart = true ) {
1743                 $title = $this->getTitle();
1744                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1745         }
1746
1747         /**
1748          * Add wikitext with a custom Title object
1749          *
1750          * @param string $text Wikitext
1751          * @param Title $title
1752          * @param bool $linestart Is this the start of a line?
1753          * @param bool $tidy Whether to use tidy
1754          * @param bool $interface Whether it is an interface message
1755          *   (for example disables conversion)
1756          */
1757         public function addWikiTextTitle( $text, Title $title, $linestart,
1758                 $tidy = false, $interface = false
1759         ) {
1760                 global $wgParser;
1761
1762                 $popts = $this->parserOptions();
1763                 $oldTidy = $popts->setTidy( $tidy );
1764                 $popts->setInterfaceMessage( (bool)$interface );
1765
1766                 $parserOutput = $wgParser->getFreshParser()->parse(
1767                         $text, $title, $popts,
1768                         $linestart, true, $this->mRevisionId
1769                 );
1770
1771                 $popts->setTidy( $oldTidy );
1772
1773                 $this->addParserOutput( $parserOutput );
1774         }
1775
1776         /**
1777          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1778          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1779          * and so on.
1780          *
1781          * @since 1.24
1782          * @param ParserOutput $parserOutput
1783          */
1784         public function addParserOutputMetadata( $parserOutput ) {
1785                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1786                 $this->addCategoryLinks( $parserOutput->getCategories() );
1787                 $this->setIndicators( $parserOutput->getIndicators() );
1788                 $this->mNewSectionLink = $parserOutput->getNewSection();
1789                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1790
1791                 if ( !$parserOutput->isCacheable() ) {
1792                         $this->enableClientCache( false );
1793                 }
1794                 $this->mNoGallery = $parserOutput->getNoGallery();
1795                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1796                 $this->addModules( $parserOutput->getModules() );
1797                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1798                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1799                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1800                 $this->mPreventClickjacking = $this->mPreventClickjacking
1801                         || $parserOutput->preventClickjacking();
1802
1803                 // Template versioning...
1804                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1805                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1806                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1807                         } else {
1808                                 $this->mTemplateIds[$ns] = $dbks;
1809                         }
1810                 }
1811                 // File versioning...
1812                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1813                         $this->mImageTimeKeys[$dbk] = $data;
1814                 }
1815
1816                 // Hooks registered in the object
1817                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1818                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1819                         list( $hookName, $data ) = $hookInfo;
1820                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1821                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1822                         }
1823                 }
1824
1825                 // Enable OOUI if requested via ParserOutput
1826                 if ( $parserOutput->getEnableOOUI() ) {
1827                         $this->enableOOUI();
1828                 }
1829
1830                 // Include parser limit report
1831                 if ( !$this->limitReportJSData ) {
1832                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1833                 }
1834
1835                 // Link flags are ignored for now, but may in the future be
1836                 // used to mark individual language links.
1837                 $linkFlags = [];
1838                 // Avoid PHP 7.1 warning of passing $this by reference
1839                 $outputPage = $this;
1840                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1841                 Hooks::run( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1842         }
1843
1844         /**
1845          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1846          * ParserOutput object, without any other metadata.
1847          *
1848          * @since 1.24
1849          * @param ParserOutput $parserOutput
1850          */
1851         public function addParserOutputContent( $parserOutput ) {
1852                 $this->addParserOutputText( $parserOutput );
1853
1854                 $this->addModules( $parserOutput->getModules() );
1855                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1856                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1857
1858                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1859         }
1860
1861         /**
1862          * Add the HTML associated with a ParserOutput object, without any metadata.
1863          *
1864          * @since 1.24
1865          * @param ParserOutput $parserOutput
1866          */
1867         public function addParserOutputText( $parserOutput ) {
1868                 $text = $parserOutput->getText();
1869                 // Avoid PHP 7.1 warning of passing $this by reference
1870                 $outputPage = $this;
1871                 Hooks::run( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1872                 $this->addHTML( $text );
1873         }
1874
1875         /**
1876          * Add everything from a ParserOutput object.
1877          *
1878          * @param ParserOutput $parserOutput
1879          */
1880         function addParserOutput( $parserOutput ) {
1881                 $this->addParserOutputMetadata( $parserOutput );
1882                 $parserOutput->setTOCEnabled( $this->mEnableTOC );
1883
1884                 // Touch section edit links only if not previously disabled
1885                 if ( $parserOutput->getEditSectionTokens() ) {
1886                         $parserOutput->setEditSectionTokens( $this->mEnableSectionEditLinks );
1887                 }
1888
1889                 $this->addParserOutputText( $parserOutput );
1890         }
1891
1892         /**
1893          * Add the output of a QuickTemplate to the output buffer
1894          *
1895          * @param QuickTemplate $template
1896          */
1897         public function addTemplate( &$template ) {
1898                 $this->addHTML( $template->getHTML() );
1899         }
1900
1901         /**
1902          * Parse wikitext and return the HTML.
1903          *
1904          * @param string $text
1905          * @param bool $linestart Is this the start of a line?
1906          * @param bool $interface Use interface language ($wgLang instead of
1907          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1908          *   This also disables LanguageConverter.
1909          * @param Language $language Target language object, will override $interface
1910          * @throws MWException
1911          * @return string HTML
1912          */
1913         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1914                 global $wgParser;
1915
1916                 if ( is_null( $this->getTitle() ) ) {
1917                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1918                 }
1919
1920                 $popts = $this->parserOptions();
1921                 if ( $interface ) {
1922                         $popts->setInterfaceMessage( true );
1923                 }
1924                 if ( $language !== null ) {
1925                         $oldLang = $popts->setTargetLanguage( $language );
1926                 }
1927
1928                 $parserOutput = $wgParser->getFreshParser()->parse(
1929                         $text, $this->getTitle(), $popts,
1930                         $linestart, true, $this->mRevisionId
1931                 );
1932
1933                 if ( $interface ) {
1934                         $popts->setInterfaceMessage( false );
1935                 }
1936                 if ( $language !== null ) {
1937                         $popts->setTargetLanguage( $oldLang );
1938                 }
1939
1940                 return $parserOutput->getText();
1941         }
1942
1943         /**
1944          * Parse wikitext, strip paragraphs, and return the HTML.
1945          *
1946          * @param string $text
1947          * @param bool $linestart Is this the start of a line?
1948          * @param bool $interface Use interface language ($wgLang instead of
1949          *   $wgContLang) while parsing language sensitive magic
1950          *   words like GRAMMAR and PLURAL
1951          * @return string HTML
1952          */
1953         public function parseInline( $text, $linestart = true, $interface = false ) {
1954                 $parsed = $this->parse( $text, $linestart, $interface );
1955                 return Parser::stripOuterParagraph( $parsed );
1956         }
1957
1958         /**
1959          * @param $maxage
1960          * @deprecated since 1.27 Use setCdnMaxage() instead
1961          */
1962         public function setSquidMaxage( $maxage ) {
1963                 $this->setCdnMaxage( $maxage );
1964         }
1965
1966         /**
1967          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1968          *
1969          * @param int $maxage Maximum cache time on the CDN, in seconds.
1970          */
1971         public function setCdnMaxage( $maxage ) {
1972                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1973         }
1974
1975         /**
1976          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1977          *
1978          * @param int $maxage Maximum cache time on the CDN, in seconds
1979          * @since 1.27
1980          */
1981         public function lowerCdnMaxage( $maxage ) {
1982                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1983                 $this->setCdnMaxage( $this->mCdnMaxage );
1984         }
1985
1986         /**
1987          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
1988          *
1989          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
1990          * the TTL is higher the older the $mtime timestamp is. Essentially, the
1991          * TTL is 90% of the age of the object, subject to the min and max.
1992          *
1993          * @param string|integer|float|bool|null $mtime Last-Modified timestamp
1994          * @param integer $minTTL Mimimum TTL in seconds [default: 1 minute]
1995          * @param integer $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
1996          * @return integer TTL in seconds
1997          * @since 1.28
1998          */
1999         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
2000                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
2001                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
2002
2003                 if ( $mtime === null || $mtime === false ) {
2004                         return $minTTL; // entity does not exist
2005                 }
2006
2007                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
2008                 $adaptiveTTL = max( .9 * $age, $minTTL );
2009                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
2010
2011                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2012
2013                 return $adaptiveTTL;
2014         }
2015
2016         /**
2017          * Use enableClientCache(false) to force it to send nocache headers
2018          *
2019          * @param bool $state
2020          *
2021          * @return bool
2022          */
2023         public function enableClientCache( $state ) {
2024                 return wfSetVar( $this->mEnableClientCache, $state );
2025         }
2026
2027         /**
2028          * Get the list of cookies that will influence on the cache
2029          *
2030          * @return array
2031          */
2032         function getCacheVaryCookies() {
2033                 static $cookies;
2034                 if ( $cookies === null ) {
2035                         $config = $this->getConfig();
2036                         $cookies = array_merge(
2037                                 SessionManager::singleton()->getVaryCookies(),
2038                                 [
2039                                         'forceHTTPS',
2040                                 ],
2041                                 $config->get( 'CacheVaryCookies' )
2042                         );
2043                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2044                 }
2045                 return $cookies;
2046         }
2047
2048         /**
2049          * Check if the request has a cache-varying cookie header
2050          * If it does, it's very important that we don't allow public caching
2051          *
2052          * @return bool
2053          */
2054         function haveCacheVaryCookies() {
2055                 $request = $this->getRequest();
2056                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2057                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2058                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2059                                 return true;
2060                         }
2061                 }
2062                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2063                 return false;
2064         }
2065
2066         /**
2067          * Add an HTTP header that will influence on the cache
2068          *
2069          * @param string $header Header name
2070          * @param string[]|null $option Options for the Key header. See
2071          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2072          * for the list of valid options.
2073          */
2074         public function addVaryHeader( $header, array $option = null ) {
2075                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2076                         $this->mVaryHeader[$header] = [];
2077                 }
2078                 if ( !is_array( $option ) ) {
2079                         $option = [];
2080                 }
2081                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2082         }
2083
2084         /**
2085          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2086          * such as Accept-Encoding or Cookie
2087          *
2088          * @return string
2089          */
2090         public function getVaryHeader() {
2091                 // If we vary on cookies, let's make sure it's always included here too.
2092                 if ( $this->getCacheVaryCookies() ) {
2093                         $this->addVaryHeader( 'Cookie' );
2094                 }
2095
2096                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2097                         $this->addVaryHeader( $header, $options );
2098                 }
2099                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2100         }
2101
2102         /**
2103          * Add an HTTP Link: header
2104          *
2105          * @param string $header Header value
2106          */
2107         public function addLinkHeader( $header ) {
2108                 $this->mLinkHeader[] = $header;
2109         }
2110
2111         /**
2112          * Return a Link: header. Based on the values of $mLinkHeader.
2113          *
2114          * @return string
2115          */
2116         public function getLinkHeader() {
2117                 if ( !$this->mLinkHeader ) {
2118                         return false;
2119                 }
2120
2121                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2122         }
2123
2124         /**
2125          * Get a complete Key header
2126          *
2127          * @return string
2128          */
2129         public function getKeyHeader() {
2130                 $cvCookies = $this->getCacheVaryCookies();
2131
2132                 $cookiesOption = [];
2133                 foreach ( $cvCookies as $cookieName ) {
2134                         $cookiesOption[] = 'param=' . $cookieName;
2135                 }
2136                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2137
2138                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2139                         $this->addVaryHeader( $header, $options );
2140                 }
2141
2142                 $headers = [];
2143                 foreach ( $this->mVaryHeader as $header => $option ) {
2144                         $newheader = $header;
2145                         if ( is_array( $option ) && count( $option ) > 0 ) {
2146                                 $newheader .= ';' . implode( ';', $option );
2147                         }
2148                         $headers[] = $newheader;
2149                 }
2150                 $key = 'Key: ' . implode( ',', $headers );
2151
2152                 return $key;
2153         }
2154
2155         /**
2156          * T23672: Add Accept-Language to Vary and Key headers
2157          * if there's no 'variant' parameter existed in GET.
2158          *
2159          * For example:
2160          *   /w/index.php?title=Main_page should always be served; but
2161          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2162          */
2163         function addAcceptLanguage() {
2164                 $title = $this->getTitle();
2165                 if ( !$title instanceof Title ) {
2166                         return;
2167                 }
2168
2169                 $lang = $title->getPageLanguage();
2170                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2171                         $variants = $lang->getVariants();
2172                         $aloption = [];
2173                         foreach ( $variants as $variant ) {
2174                                 if ( $variant === $lang->getCode() ) {
2175                                         continue;
2176                                 } else {
2177                                         $aloption[] = 'substr=' . $variant;
2178
2179                                         // IE and some other browsers use BCP 47 standards in
2180                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2181                                         // We should handle these too.
2182                                         $variantBCP47 = wfBCP47( $variant );
2183                                         if ( $variantBCP47 !== $variant ) {
2184                                                 $aloption[] = 'substr=' . $variantBCP47;
2185                                         }
2186                                 }
2187                         }
2188                         $this->addVaryHeader( 'Accept-Language', $aloption );
2189                 }
2190         }
2191
2192         /**
2193          * Set a flag which will cause an X-Frame-Options header appropriate for
2194          * edit pages to be sent. The header value is controlled by
2195          * $wgEditPageFrameOptions.
2196          *
2197          * This is the default for special pages. If you display a CSRF-protected
2198          * form on an ordinary view page, then you need to call this function.
2199          *
2200          * @param bool $enable
2201          */
2202         public function preventClickjacking( $enable = true ) {
2203                 $this->mPreventClickjacking = $enable;
2204         }
2205
2206         /**
2207          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2208          * This can be called from pages which do not contain any CSRF-protected
2209          * HTML form.
2210          */
2211         public function allowClickjacking() {
2212                 $this->mPreventClickjacking = false;
2213         }
2214
2215         /**
2216          * Get the prevent-clickjacking flag
2217          *
2218          * @since 1.24
2219          * @return bool
2220          */
2221         public function getPreventClickjacking() {
2222                 return $this->mPreventClickjacking;
2223         }
2224
2225         /**
2226          * Get the X-Frame-Options header value (without the name part), or false
2227          * if there isn't one. This is used by Skin to determine whether to enable
2228          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2229          *
2230          * @return string|false
2231          */
2232         public function getFrameOptions() {
2233                 $config = $this->getConfig();
2234                 if ( $config->get( 'BreakFrames' ) ) {
2235                         return 'DENY';
2236                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2237                         return $config->get( 'EditPageFrameOptions' );
2238                 }
2239                 return false;
2240         }
2241
2242         /**
2243          * Send cache control HTTP headers
2244          */
2245         public function sendCacheControl() {
2246                 $response = $this->getRequest()->response();
2247                 $config = $this->getConfig();
2248
2249                 $this->addVaryHeader( 'Cookie' );
2250                 $this->addAcceptLanguage();
2251
2252                 # don't serve compressed data to clients who can't handle it
2253                 # maintain different caches for logged-in users and non-logged in ones
2254                 $response->header( $this->getVaryHeader() );
2255
2256                 if ( $config->get( 'UseKeyHeader' ) ) {
2257                         $response->header( $this->getKeyHeader() );
2258                 }
2259
2260                 if ( $this->mEnableClientCache ) {
2261                         if (
2262                                 $config->get( 'UseSquid' ) &&
2263                                 !$response->hasCookies() &&
2264                                 !SessionManager::getGlobalSession()->isPersistent() &&
2265                                 !$this->isPrintable() &&
2266                                 $this->mCdnMaxage != 0 &&
2267                                 !$this->haveCacheVaryCookies()
2268                         ) {
2269                                 if ( $config->get( 'UseESI' ) ) {
2270                                         # We'll purge the proxy cache explicitly, but require end user agents
2271                                         # to revalidate against the proxy on each visit.
2272                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2273                                         wfDebug( __METHOD__ .
2274                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2275                                         # start with a shorter timeout for initial testing
2276                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2277                                         $response->header(
2278                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2279                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2280                                         );
2281                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2282                                 } else {
2283                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2284                                         # to revalidate against the proxy on each visit.
2285                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2286                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2287                                         wfDebug( __METHOD__ .
2288                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2289                                         # start with a shorter timeout for initial testing
2290                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2291                                         $response->header( "Cache-Control: " .
2292                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2293                                 }
2294                         } else {
2295                                 # We do want clients to cache if they can, but they *must* check for updates
2296                                 # on revisiting the page.
2297                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2298                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2299                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2300                         }
2301                         if ( $this->mLastModified ) {
2302                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2303                         }
2304                 } else {
2305                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2306
2307                         # In general, the absence of a last modified header should be enough to prevent
2308                         # the client from using its cache. We send a few other things just to make sure.
2309                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2310                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2311                         $response->header( 'Pragma: no-cache' );
2312                 }
2313         }
2314
2315         /**
2316          * Finally, all the text has been munged and accumulated into
2317          * the object, let's actually output it:
2318          *
2319          * @param bool $return Set to true to get the result as a string rather than sending it
2320          * @return string|null
2321          * @throws Exception
2322          * @throws FatalError
2323          * @throws MWException
2324          */
2325         public function output( $return = false ) {
2326                 global $wgContLang;
2327
2328                 if ( $this->mDoNothing ) {
2329                         return $return ? '' : null;
2330                 }
2331
2332                 $response = $this->getRequest()->response();
2333                 $config = $this->getConfig();
2334
2335                 if ( $this->mRedirect != '' ) {
2336                         # Standards require redirect URLs to be absolute
2337                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2338
2339                         $redirect = $this->mRedirect;
2340                         $code = $this->mRedirectCode;
2341
2342                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2343                                 if ( $code == '301' || $code == '303' ) {
2344                                         if ( !$config->get( 'DebugRedirects' ) ) {
2345                                                 $response->statusHeader( $code );
2346                                         }
2347                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2348                                 }
2349                                 if ( $config->get( 'VaryOnXFP' ) ) {
2350                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2351                                 }
2352                                 $this->sendCacheControl();
2353
2354                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2355                                 if ( $config->get( 'DebugRedirects' ) ) {
2356                                         $url = htmlspecialchars( $redirect );
2357                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2358                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2359                                         print "</body>\n</html>\n";
2360                                 } else {
2361                                         $response->header( 'Location: ' . $redirect );
2362                                 }
2363                         }
2364
2365                         return $return ? '' : null;
2366                 } elseif ( $this->mStatusCode ) {
2367                         $response->statusHeader( $this->mStatusCode );
2368                 }
2369
2370                 # Buffer output; final headers may depend on later processing
2371                 ob_start();
2372
2373                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2374                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2375
2376                 // Avoid Internet Explorer "compatibility view" in IE 8-10, so that
2377                 // jQuery etc. can work correctly.
2378                 $response->header( 'X-UA-Compatible: IE=Edge' );
2379
2380                 if ( !$this->mArticleBodyOnly ) {
2381                         $sk = $this->getSkin();
2382
2383                         if ( $sk->shouldPreloadLogo() ) {
2384                                 $this->addLogoPreloadLinkHeaders();
2385                         }
2386                 }
2387
2388                 $linkHeader = $this->getLinkHeader();
2389                 if ( $linkHeader ) {
2390                         $response->header( $linkHeader );
2391                 }
2392
2393                 // Prevent framing, if requested
2394                 $frameOptions = $this->getFrameOptions();
2395                 if ( $frameOptions ) {
2396                         $response->header( "X-Frame-Options: $frameOptions" );
2397                 }
2398
2399                 if ( $this->mArticleBodyOnly ) {
2400                         echo $this->mBodytext;
2401                 } else {
2402                         // Enable safe mode if requested
2403                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2404                                 $this->disallowUserJs();
2405                         }
2406
2407                         $sk = $this->getSkin();
2408                         // add skin specific modules
2409                         $modules = $sk->getDefaultModules();
2410
2411                         // Enforce various default modules for all pages and all skins
2412                         $coreModules = [
2413                                 // Keep this list as small as possible
2414                                 'site',
2415                                 'mediawiki.page.startup',
2416                                 'mediawiki.user',
2417                         ];
2418
2419                         // Support for high-density display images if enabled
2420                         if ( $config->get( 'ResponsiveImages' ) ) {
2421                                 $coreModules[] = 'mediawiki.hidpi';
2422                         }
2423
2424                         $this->addModules( $coreModules );
2425                         foreach ( $modules as $group ) {
2426                                 $this->addModules( $group );
2427                         }
2428                         MWDebug::addModules( $this );
2429
2430                         // Avoid PHP 7.1 warning of passing $this by reference
2431                         $outputPage = $this;
2432                         // Hook that allows last minute changes to the output page, e.g.
2433                         // adding of CSS or Javascript by extensions.
2434                         Hooks::run( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2435
2436                         try {
2437                                 $sk->outputPage();
2438                         } catch ( Exception $e ) {
2439                                 ob_end_clean(); // bug T129657
2440                                 throw $e;
2441                         }
2442                 }
2443
2444                 try {
2445                         // This hook allows last minute changes to final overall output by modifying output buffer
2446                         Hooks::run( 'AfterFinalPageOutput', [ $this ] );
2447                 } catch ( Exception $e ) {
2448                         ob_end_clean(); // bug T129657
2449                         throw $e;
2450                 }
2451
2452                 $this->sendCacheControl();
2453
2454                 if ( $return ) {
2455                         return ob_get_clean();
2456                 } else {
2457                         ob_end_flush();
2458                         return null;
2459                 }
2460         }
2461
2462         /**
2463          * Prepare this object to display an error page; disable caching and
2464          * indexing, clear the current text and redirect, set the page's title
2465          * and optionally an custom HTML title (content of the "<title>" tag).
2466          *
2467          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2468          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2469          *                   optional, if not passed the "<title>" attribute will be
2470          *                   based on $pageTitle
2471          */
2472         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2473                 $this->setPageTitle( $pageTitle );
2474                 if ( $htmlTitle !== false ) {
2475                         $this->setHTMLTitle( $htmlTitle );
2476                 }
2477                 $this->setRobotPolicy( 'noindex,nofollow' );
2478                 $this->setArticleRelated( false );
2479                 $this->enableClientCache( false );
2480                 $this->mRedirect = '';
2481                 $this->clearSubtitle();
2482                 $this->clearHTML();
2483         }
2484
2485         /**
2486          * Output a standard error page
2487          *
2488          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2489          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2490          * showErrorPage( 'titlemsg', $messageObject );
2491          * showErrorPage( $titleMessageObject, $messageObject );
2492          *
2493          * @param string|Message $title Message key (string) for page title, or a Message object
2494          * @param string|Message $msg Message key (string) for page text, or a Message object
2495          * @param array $params Message parameters; ignored if $msg is a Message object
2496          */
2497         public function showErrorPage( $title, $msg, $params = [] ) {
2498                 if ( !$title instanceof Message ) {
2499                         $title = $this->msg( $title );
2500                 }
2501
2502                 $this->prepareErrorPage( $title );
2503
2504                 if ( $msg instanceof Message ) {
2505                         if ( $params !== [] ) {
2506                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2507                                         . 'is discarded when the $msg argument is a Message object instead of '
2508                                         . 'a string.', E_USER_NOTICE );
2509                         }
2510                         $this->addHTML( $msg->parseAsBlock() );
2511                 } else {
2512                         $this->addWikiMsgArray( $msg, $params );
2513                 }
2514
2515                 $this->returnToMain();
2516         }
2517
2518         /**
2519          * Output a standard permission error page
2520          *
2521          * @param array $errors Error message keys or [key, param...] arrays
2522          * @param string $action Action that was denied or null if unknown
2523          */
2524         public function showPermissionsErrorPage( array $errors, $action = null ) {
2525                 foreach ( $errors as $key => $error ) {
2526                         $errors[$key] = (array)$error;
2527                 }
2528
2529                 // For some action (read, edit, create and upload), display a "login to do this action"
2530                 // error if all of the following conditions are met:
2531                 // 1. the user is not logged in
2532                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2533                 // 3. the error can be avoided simply by logging in
2534                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2535                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2536                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2537                         && ( User::groupHasPermission( 'user', $action )
2538                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2539                 ) {
2540                         $displayReturnto = null;
2541
2542                         # Due to T34276, if a user does not have read permissions,
2543                         # $this->getTitle() will just give Special:Badtitle, which is
2544                         # not especially useful as a returnto parameter. Use the title
2545                         # from the request instead, if there was one.
2546                         $request = $this->getRequest();
2547                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2548                         if ( $action == 'edit' ) {
2549                                 $msg = 'whitelistedittext';
2550                                 $displayReturnto = $returnto;
2551                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2552                                 $msg = 'nocreatetext';
2553                         } elseif ( $action == 'upload' ) {
2554                                 $msg = 'uploadnologintext';
2555                         } else { # Read
2556                                 $msg = 'loginreqpagetext';
2557                                 $displayReturnto = Title::newMainPage();
2558                         }
2559
2560                         $query = [];
2561
2562                         if ( $returnto ) {
2563                                 $query['returnto'] = $returnto->getPrefixedText();
2564
2565                                 if ( !$request->wasPosted() ) {
2566                                         $returntoquery = $request->getValues();
2567                                         unset( $returntoquery['title'] );
2568                                         unset( $returntoquery['returnto'] );
2569                                         unset( $returntoquery['returntoquery'] );
2570                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2571                                 }
2572                         }
2573                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2574                         $loginLink = $linkRenderer->makeKnownLink(
2575                                 SpecialPage::getTitleFor( 'Userlogin' ),
2576                                 $this->msg( 'loginreqlink' )->text(),
2577                                 [],
2578                                 $query
2579                         );
2580
2581                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2582                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2583
2584                         # Don't return to a page the user can't read otherwise
2585                         # we'll end up in a pointless loop
2586                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2587                                 $this->returnToMain( null, $displayReturnto );
2588                         }
2589                 } else {
2590                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2591                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2592                 }
2593         }
2594
2595         /**
2596          * Display an error page indicating that a given version of MediaWiki is
2597          * required to use it
2598          *
2599          * @param mixed $version The version of MediaWiki needed to use the page
2600          */
2601         public function versionRequired( $version ) {
2602                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2603
2604                 $this->addWikiMsg( 'versionrequiredtext', $version );
2605                 $this->returnToMain();
2606         }
2607
2608         /**
2609          * Format a list of error messages
2610          *
2611          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2612          * @param string $action Action that was denied or null if unknown
2613          * @return string The wikitext error-messages, formatted into a list.
2614          */
2615         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2616                 if ( $action == null ) {
2617                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2618                 } else {
2619                         $action_desc = $this->msg( "action-$action" )->plain();
2620                         $text = $this->msg(
2621                                 'permissionserrorstext-withaction',
2622                                 count( $errors ),
2623                                 $action_desc
2624                         )->plain() . "\n\n";
2625                 }
2626
2627                 if ( count( $errors ) > 1 ) {
2628                         $text .= '<ul class="permissions-errors">' . "\n";
2629
2630                         foreach ( $errors as $error ) {
2631                                 $text .= '<li>';
2632                                 $text .= call_user_func_array( [ $this, 'msg' ], $error )->plain();
2633                                 $text .= "</li>\n";
2634                         }
2635                         $text .= '</ul>';
2636                 } else {
2637                         $text .= "<div class=\"permissions-errors\">\n" .
2638                                         call_user_func_array( [ $this, 'msg' ], reset( $errors ) )->plain() .
2639                                         "\n</div>";
2640                 }
2641
2642                 return $text;
2643         }
2644
2645         /**
2646          * Display a page stating that the Wiki is in read-only mode.
2647          * Should only be called after wfReadOnly() has returned true.
2648          *
2649          * Historically, this function was used to show the source of the page that the user
2650          * was trying to edit and _also_ permissions error messages. The relevant code was
2651          * moved into EditPage in 1.19 (r102024 / d83c2a431c2a) and removed here in 1.25.
2652          *
2653          * @deprecated since 1.25; throw the exception directly
2654          * @throws ReadOnlyError
2655          */
2656         public function readOnlyPage() {
2657                 if ( func_num_args() > 0 ) {
2658                         throw new MWException( __METHOD__ . ' no longer accepts arguments since 1.25.' );
2659                 }
2660
2661                 throw new ReadOnlyError;
2662         }
2663
2664         /**
2665          * Turn off regular page output and return an error response
2666          * for when rate limiting has triggered.
2667          *
2668          * @deprecated since 1.25; throw the exception directly
2669          */
2670         public function rateLimited() {
2671                 wfDeprecated( __METHOD__, '1.25' );
2672                 throw new ThrottledError;
2673         }
2674
2675         /**
2676          * Show a warning about replica DB lag
2677          *
2678          * If the lag is higher than $wgSlaveLagCritical seconds,
2679          * then the warning is a bit more obvious. If the lag is
2680          * lower than $wgSlaveLagWarning, then no warning is shown.
2681          *
2682          * @param int $lag Slave lag
2683          */
2684         public function showLagWarning( $lag ) {
2685                 $config = $this->getConfig();
2686                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2687                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2688                         $message = $lag < $config->get( 'SlaveLagCritical' )
2689                                 ? 'lag-warn-normal'
2690                                 : 'lag-warn-high';
2691                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2692                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2693                 }
2694         }
2695
2696         public function showFatalError( $message ) {
2697                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2698
2699                 $this->addHTML( $message );
2700         }
2701
2702         public function showUnexpectedValueError( $name, $val ) {
2703                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2704         }
2705
2706         public function showFileCopyError( $old, $new ) {
2707                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2708         }
2709
2710         public function showFileRenameError( $old, $new ) {
2711                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2712         }
2713
2714         public function showFileDeleteError( $name ) {
2715                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2716         }
2717
2718         public function showFileNotFoundError( $name ) {
2719                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2720         }
2721
2722         /**
2723          * Add a "return to" link pointing to a specified title
2724          *
2725          * @param Title $title Title to link
2726          * @param array $query Query string parameters
2727          * @param string $text Text of the link (input is not escaped)
2728          * @param array $options Options array to pass to Linker
2729          */
2730         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2731                 $linkRenderer = MediaWikiServices::getInstance()
2732                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
2733                 $link = $this->msg( 'returnto' )->rawParams(
2734                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
2735                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2736         }
2737
2738         /**
2739          * Add a "return to" link pointing to a specified title,
2740          * or the title indicated in the request, or else the main page
2741          *
2742          * @param mixed $unused
2743          * @param Title|string $returnto Title or String to return to
2744          * @param string $returntoquery Query string for the return to link
2745          */
2746         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2747                 if ( $returnto == null ) {
2748                         $returnto = $this->getRequest()->getText( 'returnto' );
2749                 }
2750
2751                 if ( $returntoquery == null ) {
2752                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2753                 }
2754
2755                 if ( $returnto === '' ) {
2756                         $returnto = Title::newMainPage();
2757                 }
2758
2759                 if ( is_object( $returnto ) ) {
2760                         $titleObj = $returnto;
2761                 } else {
2762                         $titleObj = Title::newFromText( $returnto );
2763                 }
2764                 // We don't want people to return to external interwiki. That
2765                 // might potentially be used as part of a phishing scheme
2766                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
2767                         $titleObj = Title::newMainPage();
2768                 }
2769
2770                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2771         }
2772
2773         private function getRlClientContext() {
2774                 if ( !$this->rlClientContext ) {
2775                         $query = ResourceLoader::makeLoaderQuery(
2776                                 [], // modules; not relevant
2777                                 $this->getLanguage()->getCode(),
2778                                 $this->getSkin()->getSkinName(),
2779                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2780                                 null, // version; not relevant
2781                                 ResourceLoader::inDebugMode(),
2782                                 null, // only; not relevant
2783                                 $this->isPrintable(),
2784                                 $this->getRequest()->getBool( 'handheld' )
2785                         );
2786                         $this->rlClientContext = new ResourceLoaderContext(
2787                                 $this->getResourceLoader(),
2788                                 new FauxRequest( $query )
2789                         );
2790                 }
2791                 return $this->rlClientContext;
2792         }
2793
2794         /**
2795          * Call this to freeze the module queue and JS config and create a formatter.
2796          *
2797          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2798          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2799          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2800          * the module filters retroactively. Skins and extension hooks may also add modules until very
2801          * late in the request lifecycle.
2802          *
2803          * @return ResourceLoaderClientHtml
2804          */
2805         public function getRlClient() {
2806                 if ( !$this->rlClient ) {
2807                         $context = $this->getRlClientContext();
2808                         $rl = $this->getResourceLoader();
2809                         $this->addModules( [
2810                                 'user.options',
2811                                 'user.tokens',
2812                         ] );
2813                         $this->addModuleStyles( [
2814                                 'site.styles',
2815                                 'noscript',
2816                                 'user.styles',
2817                         ] );
2818                         $this->getSkin()->setupSkinUserCss( $this );
2819
2820                         // Prepare exempt modules for buildExemptModules()
2821                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2822                         $exemptStates = [];
2823                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2824
2825                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2826                         // Separate user-specific batch for improved cache-hit ratio.
2827                         $userBatch = [ 'user.styles', 'user' ];
2828                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2829                         $dbr = wfGetDB( DB_REPLICA );
2830                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2831                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2832
2833                         // Filter out modules handled by buildExemptModules()
2834                         $moduleStyles = array_filter( $moduleStyles,
2835                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2836                                         $module = $rl->getModule( $name );
2837                                         if ( $module ) {
2838                                                 if ( $name === 'user.styles' && $this->isUserCssPreview() ) {
2839                                                         $exemptStates[$name] = 'ready';
2840                                                         // Special case in buildExemptModules()
2841                                                         return false;
2842                                                 }
2843                                                 $group = $module->getGroup();
2844                                                 if ( isset( $exemptGroups[$group] ) ) {
2845                                                         $exemptStates[$name] = 'ready';
2846                                                         if ( !$module->isKnownEmpty( $context ) ) {
2847                                                                 // E.g. Don't output empty <styles>
2848                                                                 $exemptGroups[$group][] = $name;
2849                                                         }
2850                                                         return false;
2851                                                 }
2852                                         }
2853                                         return true;
2854                                 }
2855                         );
2856                         $this->rlExemptStyleModules = $exemptGroups;
2857
2858                         $isUserModuleFiltered = !$this->filterModules( [ 'user' ] );
2859                         // If this page filters out 'user', makeResourceLoaderLink will drop it.
2860                         // Avoid indefinite "loading" state or untrue "ready" state (T145368).
2861                         if ( !$isUserModuleFiltered ) {
2862                                 // Manually handled by getBottomScripts()
2863                                 $userModule = $rl->getModule( 'user' );
2864                                 $userState = $userModule->isKnownEmpty( $context ) && !$this->isUserJsPreview()
2865                                         ? 'ready'
2866                                         : 'loading';
2867                                 $this->rlUserModuleState = $exemptStates['user'] = $userState;
2868                         }
2869
2870                         $rlClient = new ResourceLoaderClientHtml( $context, $this->getTarget() );
2871                         $rlClient->setConfig( $this->getJSVars() );
2872                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2873                         $rlClient->setModuleStyles( $moduleStyles );
2874                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2875                         $rlClient->setExemptStates( $exemptStates );
2876                         $this->rlClient = $rlClient;
2877                 }
2878                 return $this->rlClient;
2879         }
2880
2881         /**
2882          * @param Skin $sk The given Skin
2883          * @param bool $includeStyle Unused
2884          * @return string The doctype, opening "<html>", and head element.
2885          */
2886         public function headElement( Skin $sk, $includeStyle = true ) {
2887                 global $wgContLang;
2888
2889                 $userdir = $this->getLanguage()->getDir();
2890                 $sitedir = $wgContLang->getDir();
2891
2892                 $pieces = [];
2893                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2894                         $this->getRlClient()->getDocumentAttributes(),
2895                         $sk->getHtmlElementAttributes()
2896                 ) );
2897                 $pieces[] = Html::openElement( 'head' );
2898
2899                 if ( $this->getHTMLTitle() == '' ) {
2900                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2901                 }
2902
2903                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2904                         // Add <meta charset="UTF-8">
2905                         // This should be before <title> since it defines the charset used by
2906                         // text including the text inside <title>.
2907                         // The spec recommends defining XHTML5's charset using the XML declaration
2908                         // instead of meta.
2909                         // Our XML declaration is output by Html::htmlHeader.
2910                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2911                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2912                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2913                 }
2914
2915                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2916                 $pieces[] = $this->getRlClient()->getHeadHtml();
2917                 $pieces[] = $this->buildExemptModules();
2918                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2919                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2920                 $pieces[] = Html::closeElement( 'head' );
2921
2922                 $bodyClasses = [];
2923                 $bodyClasses[] = 'mediawiki';
2924
2925                 # Classes for LTR/RTL directionality support
2926                 $bodyClasses[] = $userdir;
2927                 $bodyClasses[] = "sitedir-$sitedir";
2928
2929                 $underline = $this->getUser()->getOption( 'underline' );
2930                 if ( $underline < 2 ) {
2931                         // The following classes can be used here:
2932                         // * mw-underline-always
2933                         // * mw-underline-never
2934                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2935                 }
2936
2937                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2938                         # A <body> class is probably not the best way to do this . . .
2939                         $bodyClasses[] = 'capitalize-all-nouns';
2940                 }
2941
2942                 // Parser feature migration class
2943                 // The idea is that this will eventually be removed, after the wikitext
2944                 // which requires it is cleaned up.
2945                 $bodyClasses[] = 'mw-hide-empty-elt';
2946
2947                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2948                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2949                 $bodyClasses[] =
2950                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2951
2952                 $bodyAttrs = [];
2953                 // While the implode() is not strictly needed, it's used for backwards compatibility
2954                 // (this used to be built as a string and hooks likely still expect that).
2955                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2956
2957                 // Allow skins and extensions to add body attributes they need
2958                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2959                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2960
2961                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2962
2963                 return self::combineWrappedStrings( $pieces );
2964         }
2965
2966         /**
2967          * Get a ResourceLoader object associated with this OutputPage
2968          *
2969          * @return ResourceLoader
2970          */
2971         public function getResourceLoader() {
2972                 if ( is_null( $this->mResourceLoader ) ) {
2973                         $this->mResourceLoader = new ResourceLoader(
2974                                 $this->getConfig(),
2975                                 LoggerFactory::getInstance( 'resourceloader' )
2976                         );
2977                 }
2978                 return $this->mResourceLoader;
2979         }
2980
2981         /**
2982          * Explicily load or embed modules on a page.
2983          *
2984          * @param array|string $modules One or more module names
2985          * @param string $only ResourceLoaderModule TYPE_ class constant
2986          * @param array $extraQuery [optional] Array with extra query parameters for the request
2987          * @return string|WrappedStringList HTML
2988          */
2989         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2990                 // Apply 'target' and 'origin' filters
2991                 $modules = $this->filterModules( (array)$modules, null, $only );
2992
2993                 return ResourceLoaderClientHtml::makeLoad(
2994                         $this->getRlClientContext(),
2995                         $modules,
2996                         $only,
2997                         $extraQuery
2998                 );
2999         }
3000
3001         /**
3002          * Combine WrappedString chunks and filter out empty ones
3003          *
3004          * @param array $chunks
3005          * @return string|WrappedStringList HTML
3006          */
3007         protected static function combineWrappedStrings( array $chunks ) {
3008                 // Filter out empty values
3009                 $chunks = array_filter( $chunks, 'strlen' );
3010                 return WrappedString::join( "\n", $chunks );
3011         }
3012
3013         private function isUserJsPreview() {
3014                 return $this->getConfig()->get( 'AllowUserJs' )
3015                         && $this->getTitle()
3016                         && $this->getTitle()->isJsSubpage()
3017                         && $this->userCanPreview();
3018         }
3019
3020         private function isUserCssPreview() {
3021                 return $this->getConfig()->get( 'AllowUserCss' )
3022                         && $this->getTitle()
3023                         && $this->getTitle()->isCssSubpage()
3024                         && $this->userCanPreview();
3025         }
3026
3027         /**
3028          * JS stuff to put at the bottom of the `<body>`. These are modules with position 'bottom',
3029          * legacy scripts ($this->mScripts), and user JS.
3030          *
3031          * @return string|WrappedStringList HTML
3032          */
3033         public function getBottomScripts() {
3034                 $chunks = [];
3035                 $chunks[] = $this->getRlClient()->getBodyHtml();
3036
3037                 // Legacy non-ResourceLoader scripts
3038                 $chunks[] = $this->mScripts;
3039
3040                 // Exempt 'user' module
3041                 // - May need excludepages for live preview. (T28283)
3042                 // - Must use TYPE_COMBINED so its response is handled by mw.loader.implement() which
3043                 //   ensures execution is scheduled after the "site" module.
3044                 // - Don't load if module state is already resolved as "ready".
3045                 if ( $this->rlUserModuleState === 'loading' ) {
3046                         if ( $this->isUserJsPreview() ) {
3047                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED,
3048                                         [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3049                                 );
3050                                 $chunks[] = ResourceLoader::makeInlineScript(
3051                                         Xml::encodeJsCall( 'mw.loader.using', [
3052                                                 [ 'user', 'site' ],
3053                                                 new XmlJsCode(
3054                                                         'function () {'
3055                                                                 . Xml::encodeJsCall( '$.globalEval', [
3056                                                                         $this->getRequest()->getText( 'wpTextbox1' )
3057                                                                 ] )
3058                                                                 . '}'
3059                                                 )
3060                                         ] )
3061                                 );
3062                                 // FIXME: If the user is previewing, say, ./vector.js, his ./common.js will be loaded
3063                                 // asynchronously and may arrive *after* the inline script here. So the previewed code
3064                                 // may execute before ./common.js runs. Normally, ./common.js runs before ./vector.js.
3065                                 // Similarly, when previewing ./common.js and the user module does arrive first,
3066                                 // it will arrive without common.js and the inline script runs after.
3067                                 // Thus running common after the excluded subpage.
3068                         } else {
3069                                 // Load normally
3070                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED );
3071                         }
3072                 }
3073
3074                 if ( $this->limitReportJSData ) {
3075                         $chunks[] = ResourceLoader::makeInlineScript(
3076                                 ResourceLoader::makeConfigSetScript(
3077                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3078                                 )
3079                         );
3080                 }
3081
3082                 return self::combineWrappedStrings( $chunks );
3083         }
3084
3085         /**
3086          * Get the javascript config vars to include on this page
3087          *
3088          * @return array Array of javascript config vars
3089          * @since 1.23
3090          */
3091         public function getJsConfigVars() {
3092                 return $this->mJsConfigVars;
3093         }
3094
3095         /**
3096          * Add one or more variables to be set in mw.config in JavaScript
3097          *
3098          * @param string|array $keys Key or array of key/value pairs
3099          * @param mixed $value [optional] Value of the configuration variable
3100          */
3101         public function addJsConfigVars( $keys, $value = null ) {
3102                 if ( is_array( $keys ) ) {
3103                         foreach ( $keys as $key => $value ) {
3104                                 $this->mJsConfigVars[$key] = $value;
3105                         }
3106                         return;
3107                 }
3108
3109                 $this->mJsConfigVars[$keys] = $value;
3110         }
3111
3112         /**
3113          * Get an array containing the variables to be set in mw.config in JavaScript.
3114          *
3115          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3116          * - in other words, page-independent/site-wide variables (without state).
3117          * You will only be adding bloat to the html page and causing page caches to
3118          * have to be purged on configuration changes.
3119          * @return array
3120          */
3121         public function getJSVars() {
3122                 global $wgContLang;
3123
3124                 $curRevisionId = 0;
3125                 $articleId = 0;
3126                 $canonicalSpecialPageName = false; # T23115
3127
3128                 $title = $this->getTitle();
3129                 $ns = $title->getNamespace();
3130                 $canonicalNamespace = MWNamespace::exists( $ns )
3131                         ? MWNamespace::getCanonicalName( $ns )
3132                         : $title->getNsText();
3133
3134                 $sk = $this->getSkin();
3135                 // Get the relevant title so that AJAX features can use the correct page name
3136                 // when making API requests from certain special pages (T36972).
3137                 $relevantTitle = $sk->getRelevantTitle();
3138                 $relevantUser = $sk->getRelevantUser();
3139
3140                 if ( $ns == NS_SPECIAL ) {
3141                         list( $canonicalSpecialPageName, /*...*/ ) =
3142                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3143                 } elseif ( $this->canUseWikiPage() ) {
3144                         $wikiPage = $this->getWikiPage();
3145                         $curRevisionId = $wikiPage->getLatest();
3146                         $articleId = $wikiPage->getId();
3147                 }
3148
3149                 $lang = $title->getPageViewLanguage();
3150
3151                 // Pre-process information
3152                 $separatorTransTable = $lang->separatorTransformTable();
3153                 $separatorTransTable = $separatorTransTable ? $separatorTransTable : [];
3154                 $compactSeparatorTransTable = [
3155                         implode( "\t", array_keys( $separatorTransTable ) ),
3156                         implode( "\t", $separatorTransTable ),
3157                 ];
3158                 $digitTransTable = $lang->digitTransformTable();
3159                 $digitTransTable = $digitTransTable ? $digitTransTable : [];
3160                 $compactDigitTransTable = [
3161                         implode( "\t", array_keys( $digitTransTable ) ),
3162                         implode( "\t", $digitTransTable ),
3163                 ];
3164
3165                 $user = $this->getUser();
3166
3167                 $vars = [
3168                         'wgCanonicalNamespace' => $canonicalNamespace,
3169                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3170                         'wgNamespaceNumber' => $title->getNamespace(),
3171                         'wgPageName' => $title->getPrefixedDBkey(),
3172                         'wgTitle' => $title->getText(),
3173                         'wgCurRevisionId' => $curRevisionId,
3174                         'wgRevisionId' => (int)$this->getRevisionId(),
3175                         'wgArticleId' => $articleId,
3176                         'wgIsArticle' => $this->isArticle(),
3177                         'wgIsRedirect' => $title->isRedirect(),
3178                         'wgAction' => Action::getActionName( $this->getContext() ),
3179                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3180                         'wgUserGroups' => $user->getEffectiveGroups(),
3181                         'wgCategories' => $this->getCategories(),
3182                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3183                         'wgPageContentLanguage' => $lang->getCode(),
3184                         'wgPageContentModel' => $title->getContentModel(),
3185                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3186                         'wgDigitTransformTable' => $compactDigitTransTable,
3187                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3188                         'wgMonthNames' => $lang->getMonthNamesArray(),
3189                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3190                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3191                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3192                         'wgRequestId' => WebRequest::getRequestId(),
3193                 ];
3194
3195                 if ( $user->isLoggedIn() ) {
3196                         $vars['wgUserId'] = $user->getId();
3197                         $vars['wgUserEditCount'] = $user->getEditCount();
3198                         $userReg = $user->getRegistration();
3199                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3200                         // Get the revision ID of the oldest new message on the user's talk
3201                         // page. This can be used for constructing new message alerts on
3202                         // the client side.
3203                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3204                 }
3205
3206                 if ( $wgContLang->hasVariants() ) {
3207                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3208                 }
3209                 // Same test as SkinTemplate
3210                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3211                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3212
3213                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3214                         && $relevantTitle->quickUserCan( 'edit', $user )
3215                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3216
3217                 foreach ( $title->getRestrictionTypes() as $type ) {
3218                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3219                 }
3220
3221                 if ( $title->isMainPage() ) {
3222                         $vars['wgIsMainPage'] = true;
3223                 }
3224
3225                 if ( $this->mRedirectedFrom ) {
3226                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3227                 }
3228
3229                 if ( $relevantUser ) {
3230                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3231                 }
3232
3233                 // Allow extensions to add their custom variables to the mw.config map.
3234                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3235                 // page-dependant but site-wide (without state).
3236                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3237                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3238
3239                 // Merge in variables from addJsConfigVars last
3240                 return array_merge( $vars, $this->getJsConfigVars() );
3241         }
3242
3243         /**
3244          * To make it harder for someone to slip a user a fake
3245          * user-JavaScript or user-CSS preview, a random token
3246          * is associated with the login session. If it's not
3247          * passed back with the preview request, we won't render
3248          * the code.
3249          *
3250          * @return bool
3251          */
3252         public function userCanPreview() {
3253                 $request = $this->getRequest();
3254                 if (
3255                         $request->getVal( 'action' ) !== 'submit' ||
3256                         !$request->getCheck( 'wpPreview' ) ||
3257                         !$request->wasPosted()
3258                 ) {
3259                         return false;
3260                 }
3261
3262                 $user = $this->getUser();
3263
3264                 if ( !$user->isLoggedIn() ) {
3265                         // Anons have predictable edit tokens
3266                         return false;
3267                 }
3268                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3269                         return false;
3270                 }
3271
3272                 $title = $this->getTitle();
3273                 if ( !$title->isJsSubpage() && !$title->isCssSubpage() ) {
3274                         return false;
3275                 }
3276                 if ( !$title->isSubpageOf( $user->getUserPage() ) ) {
3277                         // Don't execute another user's CSS or JS on preview (T85855)
3278                         return false;
3279                 }
3280
3281                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3282                 if ( count( $errors ) !== 0 ) {
3283                         return false;
3284                 }
3285
3286                 return true;
3287         }
3288
3289         /**
3290          * @return array Array in format "link name or number => 'link html'".
3291          */
3292         public function getHeadLinksArray() {
3293                 global $wgVersion;
3294
3295                 $tags = [];
3296                 $config = $this->getConfig();
3297
3298                 $canonicalUrl = $this->mCanonicalUrl;
3299
3300                 $tags['meta-generator'] = Html::element( 'meta', [
3301                         'name' => 'generator',
3302                         'content' => "MediaWiki $wgVersion",
3303                 ] );
3304
3305                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3306                         $tags['meta-referrer'] = Html::element( 'meta', [
3307                                 'name' => 'referrer',
3308                                 'content' => $config->get( 'ReferrerPolicy' )
3309                         ] );
3310                 }
3311
3312                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3313                 if ( $p !== 'index,follow' ) {
3314                         // http://www.robotstxt.org/wc/meta-user.html
3315                         // Only show if it's different from the default robots policy
3316                         $tags['meta-robots'] = Html::element( 'meta', [
3317                                 'name' => 'robots',
3318                                 'content' => $p,
3319                         ] );
3320                 }
3321
3322                 foreach ( $this->mMetatags as $tag ) {
3323                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3324                                 $a = 'http-equiv';
3325                                 $tag[0] = substr( $tag[0], 5 );
3326                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3327                                 $a = 'property';
3328                         } else {
3329                                 $a = 'name';
3330                         }
3331                         $tagName = "meta-{$tag[0]}";
3332                         if ( isset( $tags[$tagName] ) ) {
3333                                 $tagName .= $tag[1];
3334                         }
3335                         $tags[$tagName] = Html::element( 'meta',
3336                                 [
3337                                         $a => $tag[0],
3338                                         'content' => $tag[1]
3339                                 ]
3340                         );
3341                 }
3342
3343                 foreach ( $this->mLinktags as $tag ) {
3344                         $tags[] = Html::element( 'link', $tag );
3345                 }
3346
3347                 # Universal edit button
3348                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3349                         $user = $this->getUser();
3350                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3351                                 && ( $this->getTitle()->exists() ||
3352                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3353                         ) {
3354                                 // Original UniversalEditButton
3355                                 $msg = $this->msg( 'edit' )->text();
3356                                 $tags['universal-edit-button'] = Html::element( 'link', [
3357                                         'rel' => 'alternate',
3358                                         'type' => 'application/x-wiki',
3359                                         'title' => $msg,
3360                                         'href' => $this->getTitle()->getEditURL(),
3361                                 ] );
3362                                 // Alternate edit link
3363                                 $tags['alternative-edit'] = Html::element( 'link', [
3364                                         'rel' => 'edit',
3365                                         'title' => $msg,
3366                                         'href' => $this->getTitle()->getEditURL(),
3367                                 ] );
3368                         }
3369                 }
3370
3371                 # Generally the order of the favicon and apple-touch-icon links
3372                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3373                 # uses whichever one appears later in the HTML source. Make sure
3374                 # apple-touch-icon is specified first to avoid this.
3375                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3376                         $tags['apple-touch-icon'] = Html::element( 'link', [
3377                                 'rel' => 'apple-touch-icon',
3378                                 'href' => $config->get( 'AppleTouchIcon' )
3379                         ] );
3380                 }
3381
3382                 if ( $config->get( 'Favicon' ) !== false ) {
3383                         $tags['favicon'] = Html::element( 'link', [
3384                                 'rel' => 'shortcut icon',
3385                                 'href' => $config->get( 'Favicon' )
3386                         ] );
3387                 }
3388
3389                 # OpenSearch description link
3390                 $tags['opensearch'] = Html::element( 'link', [
3391                         'rel' => 'search',
3392                         'type' => 'application/opensearchdescription+xml',
3393                         'href' => wfScript( 'opensearch_desc' ),
3394                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3395                 ] );
3396
3397                 if ( $config->get( 'EnableAPI' ) ) {
3398                         # Real Simple Discovery link, provides auto-discovery information
3399                         # for the MediaWiki API (and potentially additional custom API
3400                         # support such as WordPress or Twitter-compatible APIs for a
3401                         # blogging extension, etc)
3402                         $tags['rsd'] = Html::element( 'link', [
3403                                 'rel' => 'EditURI',
3404                                 'type' => 'application/rsd+xml',
3405                                 // Output a protocol-relative URL here if $wgServer is protocol-relative.
3406                                 // Whether RSD accepts relative or protocol-relative URLs is completely
3407                                 // undocumented, though.
3408                                 'href' => wfExpandUrl( wfAppendQuery(
3409                                         wfScript( 'api' ),
3410                                         [ 'action' => 'rsd' ] ),
3411                                         PROTO_RELATIVE
3412                                 ),
3413                         ] );
3414                 }
3415
3416                 # Language variants
3417                 if ( !$config->get( 'DisableLangConversion' ) ) {
3418                         $lang = $this->getTitle()->getPageLanguage();
3419                         if ( $lang->hasVariants() ) {
3420                                 $variants = $lang->getVariants();
3421                                 foreach ( $variants as $variant ) {
3422                                         $tags["variant-$variant"] = Html::element( 'link', [
3423                                                 'rel' => 'alternate',
3424                                                 'hreflang' => wfBCP47( $variant ),
3425                                                 'href' => $this->getTitle()->getLocalURL(
3426                                                         [ 'variant' => $variant ] )
3427                                                 ]
3428                                         );
3429                                 }
3430                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3431                                 $tags["variant-x-default"] = Html::element( 'link', [
3432                                         'rel' => 'alternate',
3433                                         'hreflang' => 'x-default',
3434                                         'href' => $this->getTitle()->getLocalURL() ] );
3435                         }
3436                 }
3437
3438                 # Copyright
3439                 if ( $this->copyrightUrl !== null ) {
3440                         $copyright = $this->copyrightUrl;
3441                 } else {
3442                         $copyright = '';
3443                         if ( $config->get( 'RightsPage' ) ) {
3444                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3445
3446                                 if ( $copy ) {
3447                                         $copyright = $copy->getLocalURL();
3448                                 }
3449                         }
3450
3451                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3452                                 $copyright = $config->get( 'RightsUrl' );
3453                         }
3454                 }
3455
3456                 if ( $copyright ) {
3457                         $tags['copyright'] = Html::element( 'link', [
3458                                 'rel' => 'copyright',
3459                                 'href' => $copyright ]
3460                         );
3461                 }
3462
3463                 # Feeds
3464                 if ( $config->get( 'Feed' ) ) {
3465                         $feedLinks = [];
3466
3467                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3468                                 # Use the page name for the title.  In principle, this could
3469                                 # lead to issues with having the same name for different feeds
3470                                 # corresponding to the same page, but we can't avoid that at
3471                                 # this low a level.
3472
3473                                 $feedLinks[] = $this->feedLink(
3474                                         $format,
3475                                         $link,
3476                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3477                                         $this->msg(
3478                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3479                                         )->text()
3480                                 );
3481                         }
3482
3483                         # Recent changes feed should appear on every page (except recentchanges,
3484                         # that would be redundant). Put it after the per-page feed to avoid
3485                         # changing existing behavior. It's still available, probably via a
3486                         # menu in your browser. Some sites might have a different feed they'd
3487                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3488                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3489                         # If so, use it instead.
3490                         $sitename = $config->get( 'Sitename' );
3491                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3492                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3493                                         // Note, this->feedLink escapes the url.
3494                                         $feedLinks[] = $this->feedLink(
3495                                                 $type,
3496                                                 $feedUrl,
3497                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3498                                         );
3499                                 }
3500                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3501                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3502                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3503                                         $feedLinks[] = $this->feedLink(
3504                                                 $format,
3505                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3506                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3507                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3508                                         );
3509                                 }
3510                         }
3511
3512                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3513                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3514                         # use OutputPage::addFeedLink() instead.
3515                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3516
3517                         $tags += $feedLinks;
3518                 }
3519
3520                 # Canonical URL
3521                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3522                         if ( $canonicalUrl !== false ) {
3523                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3524                         } else {
3525                                 if ( $this->isArticleRelated() ) {
3526                                         // This affects all requests where "setArticleRelated" is true. This is
3527                                         // typically all requests that show content (query title, curid, oldid, diff),
3528                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3529                                         // It does not apply to File pages and Special pages.
3530                                         // 'history' and 'info' actions address page metadata rather than the page
3531                                         // content itself, so they may not be canonicalized to the view page url.
3532                                         // TODO: this ought to be better encapsulated in the Action class.
3533                                         $action = Action::getActionName( $this->getContext() );
3534                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3535                                                 $query = "action={$action}";
3536                                         } else {
3537                                                 $query = '';
3538                                         }
3539                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3540                                 } else {
3541                                         $reqUrl = $this->getRequest()->getRequestURL();
3542                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3543                                 }
3544                         }
3545                 }
3546                 if ( $canonicalUrl !== false ) {
3547                         $tags[] = Html::element( 'link', [
3548                                 'rel' => 'canonical',
3549                                 'href' => $canonicalUrl
3550                         ] );
3551                 }
3552
3553                 return $tags;
3554         }
3555
3556         /**
3557          * Generate a "<link rel/>" for a feed.
3558          *
3559          * @param string $type Feed type
3560          * @param string $url URL to the feed
3561          * @param string $text Value of the "title" attribute
3562          * @return string HTML fragment
3563          */
3564         private function feedLink( $type, $url, $text ) {
3565                 return Html::element( 'link', [
3566                         'rel' => 'alternate',
3567                         'type' => "application/$type+xml",
3568                         'title' => $text,
3569                         'href' => $url ]
3570                 );
3571         }
3572
3573         /**
3574          * Add a local or specified stylesheet, with the given media options.
3575          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3576          *
3577          * @param string $style URL to the file
3578          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3579          * @param string $condition For IE conditional comments, specifying an IE version
3580          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3581          */
3582         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3583                 $options = [];
3584                 if ( $media ) {
3585                         $options['media'] = $media;
3586                 }
3587                 if ( $condition ) {
3588                         $options['condition'] = $condition;
3589                 }
3590                 if ( $dir ) {
3591                         $options['dir'] = $dir;
3592                 }
3593                 $this->styles[$style] = $options;
3594         }
3595
3596         /**
3597          * Adds inline CSS styles
3598          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3599          *
3600          * @param mixed $style_css Inline CSS
3601          * @param string $flip Set to 'flip' to flip the CSS if needed
3602          */
3603         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3604                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3605                         # If wanted, and the interface is right-to-left, flip the CSS
3606                         $style_css = CSSJanus::transform( $style_css, true, false );
3607                 }
3608                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3609         }
3610
3611         /**
3612          * Build exempt modules and legacy non-ResourceLoader styles.
3613          *
3614          * @return string|WrappedStringList HTML
3615          */
3616         protected function buildExemptModules() {
3617                 global $wgContLang;
3618
3619                 $chunks = [];
3620                 // Things that go after the ResourceLoaderDynamicStyles marker
3621                 $append = [];
3622
3623                 // Exempt 'user' styles module (may need 'excludepages' for live preview)
3624                 if ( $this->isUserCssPreview() ) {
3625                         $append[] = $this->makeResourceLoaderLink(
3626                                 'user.styles',
3627                                 ResourceLoaderModule::TYPE_STYLES,
3628                                 [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3629                         );
3630
3631                         // Load the previewed CSS. Janus it if needed.
3632                         // User-supplied CSS is assumed to in the wiki's content language.
3633                         $previewedCSS = $this->getRequest()->getText( 'wpTextbox1' );
3634                         if ( $this->getLanguage()->getDir() !== $wgContLang->getDir() ) {
3635                                 $previewedCSS = CSSJanus::transform( $previewedCSS, true, false );
3636                         }
3637                         $append[] = Html::inlineStyle( $previewedCSS );
3638                 }
3639
3640                 // We want site, private and user styles to override dynamically added styles from
3641                 // general modules, but we want dynamically added styles to override statically added
3642                 // style modules. So the order has to be:
3643                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3644                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3645                 // - ResourceLoaderDynamicStyles marker
3646                 // - site/private/user styles
3647
3648                 // Add legacy styles added through addStyle()/addInlineStyle() here
3649                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3650
3651                 $chunks[] = Html::element(
3652                         'meta',
3653                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3654                 );
3655
3656                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3657                         $chunks[] = $this->makeResourceLoaderLink( $moduleNames,
3658                                 ResourceLoaderModule::TYPE_STYLES
3659                         );
3660                 }
3661
3662                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3663         }
3664
3665         /**
3666          * @return array
3667          */
3668         public function buildCssLinksArray() {
3669                 $links = [];
3670
3671                 // Add any extension CSS
3672                 foreach ( $this->mExtStyles as $url ) {
3673                         $this->addStyle( $url );
3674                 }
3675                 $this->mExtStyles = [];
3676
3677                 foreach ( $this->styles as $file => $options ) {
3678                         $link = $this->styleLink( $file, $options );
3679                         if ( $link ) {
3680                                 $links[$file] = $link;
3681                         }
3682                 }
3683                 return $links;
3684         }
3685
3686         /**
3687          * Generate \<link\> tags for stylesheets
3688          *
3689          * @param string $style URL to the file
3690          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3691          * @return string HTML fragment
3692          */
3693         protected function styleLink( $style, array $options ) {
3694                 if ( isset( $options['dir'] ) ) {
3695                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3696                                 return '';
3697                         }
3698                 }
3699
3700                 if ( isset( $options['media'] ) ) {
3701                         $media = self::transformCssMedia( $options['media'] );
3702                         if ( is_null( $media ) ) {
3703                                 return '';
3704                         }
3705                 } else {
3706                         $media = 'all';
3707                 }
3708
3709                 if ( substr( $style, 0, 1 ) == '/' ||
3710                         substr( $style, 0, 5 ) == 'http:' ||
3711                         substr( $style, 0, 6 ) == 'https:' ) {
3712                         $url = $style;
3713                 } else {
3714                         $config = $this->getConfig();
3715                         $url = $config->get( 'StylePath' ) . '/' . $style . '?' .
3716                                 $config->get( 'StyleVersion' );
3717                 }
3718
3719                 $link = Html::linkedStyle( $url, $media );
3720
3721                 if ( isset( $options['condition'] ) ) {
3722                         $condition = htmlspecialchars( $options['condition'] );
3723                         $link = "<!--[if $condition]>$link<![endif]-->";
3724                 }
3725                 return $link;
3726         }
3727
3728         /**
3729          * Transform path to web-accessible static resource.
3730          *
3731          * This is used to add a validation hash as query string.
3732          * This aids various behaviors:
3733          *
3734          * - Put long Cache-Control max-age headers on responses for improved
3735          *   cache performance.
3736          * - Get the correct version of a file as expected by the current page.
3737          * - Instantly get the updated version of a file after deployment.
3738          *
3739          * Avoid using this for urls included in HTML as otherwise clients may get different
3740          * versions of a resource when navigating the site depending on when the page was cached.
3741          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3742          * an external stylesheet).
3743          *
3744          * @since 1.27
3745          * @param Config $config
3746          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3747          * @return string URL
3748          */
3749         public static function transformResourcePath( Config $config, $path ) {
3750                 global $IP;
3751
3752                 $localDir = $IP;
3753                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3754                 if ( $remotePathPrefix === '' ) {
3755                         // The configured base path is required to be empty string for
3756                         // wikis in the domain root
3757                         $remotePath = '/';
3758                 } else {
3759                         $remotePath = $remotePathPrefix;
3760                 }
3761                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3762                         // - Path is outside wgResourceBasePath, ignore.
3763                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3764                         return $path;
3765                 }
3766                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3767                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3768                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3769                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3770                 $uploadPath = $config->get( 'UploadPath' );
3771                 if ( strpos( $path, $uploadPath ) === 0 ) {
3772                         $localDir = $config->get( 'UploadDirectory' );
3773                         $remotePathPrefix = $remotePath = $uploadPath;
3774                 }
3775
3776                 $path = RelPath\getRelativePath( $path, $remotePath );
3777                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3778         }
3779
3780         /**
3781          * Utility method for transformResourceFilePath().
3782          *
3783          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3784          *
3785          * @since 1.27
3786          * @param string $remotePath URL path prefix that points to $localPath
3787          * @param string $localPath File directory exposed at $remotePath
3788          * @param string $file Path to target file relative to $localPath
3789          * @return string URL
3790          */
3791         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3792                 $hash = md5_file( "$localPath/$file" );
3793                 if ( $hash === false ) {
3794                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3795                         $hash = '';
3796                 }
3797                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3798         }
3799
3800         /**
3801          * Transform "media" attribute based on request parameters
3802          *
3803          * @param string $media Current value of the "media" attribute
3804          * @return string Modified value of the "media" attribute, or null to skip
3805          * this stylesheet
3806          */
3807         public static function transformCssMedia( $media ) {
3808                 global $wgRequest;
3809
3810                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3811                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3812
3813                 // Switch in on-screen display for media testing
3814                 $switches = [
3815                         'printable' => 'print',
3816                         'handheld' => 'handheld',
3817                 ];
3818                 foreach ( $switches as $switch => $targetMedia ) {
3819                         if ( $wgRequest->getBool( $switch ) ) {
3820                                 if ( $media == $targetMedia ) {
3821                                         $media = '';
3822                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3823                                         /* This regex will not attempt to understand a comma-separated media_query_list
3824                                          *
3825                                          * Example supported values for $media:
3826                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3827                                          * Example NOT supported value for $media:
3828                                          * '3d-glasses, screen, print and resolution > 90dpi'
3829                                          *
3830                                          * If it's a print request, we never want any kind of screen stylesheets
3831                                          * If it's a handheld request (currently the only other choice with a switch),
3832                                          * we don't want simple 'screen' but we might want screen queries that
3833                                          * have a max-width or something, so we'll pass all others on and let the
3834                                          * client do the query.
3835                                          */
3836                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3837                                                 return null;
3838                                         }
3839                                 }
3840                         }
3841                 }
3842
3843                 return $media;
3844         }
3845
3846         /**
3847          * Add a wikitext-formatted message to the output.
3848          * This is equivalent to:
3849          *
3850          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3851          */
3852         public function addWikiMsg( /*...*/ ) {
3853                 $args = func_get_args();
3854                 $name = array_shift( $args );
3855                 $this->addWikiMsgArray( $name, $args );
3856         }
3857
3858         /**
3859          * Add a wikitext-formatted message to the output.
3860          * Like addWikiMsg() except the parameters are taken as an array
3861          * instead of a variable argument list.
3862          *
3863          * @param string $name
3864          * @param array $args
3865          */
3866         public function addWikiMsgArray( $name, $args ) {
3867                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3868         }
3869
3870         /**
3871          * This function takes a number of message/argument specifications, wraps them in
3872          * some overall structure, and then parses the result and adds it to the output.
3873          *
3874          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3875          * and so on. The subsequent arguments may be either
3876          * 1) strings, in which case they are message names, or
3877          * 2) arrays, in which case, within each array, the first element is the message
3878          *    name, and subsequent elements are the parameters to that message.
3879          *
3880          * Don't use this for messages that are not in the user's interface language.
3881          *
3882          * For example:
3883          *
3884          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3885          *
3886          * Is equivalent to:
3887          *
3888          *    $wgOut->addWikiText( "<div class='error'>\n"
3889          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3890          *
3891          * The newline after the opening div is needed in some wikitext. See T21226.
3892          *
3893          * @param string $wrap
3894          */
3895         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3896                 $msgSpecs = func_get_args();
3897                 array_shift( $msgSpecs );
3898                 $msgSpecs = array_values( $msgSpecs );
3899                 $s = $wrap;
3900                 foreach ( $msgSpecs as $n => $spec ) {
3901                         if ( is_array( $spec ) ) {
3902                                 $args = $spec;
3903                                 $name = array_shift( $args );
3904                                 if ( isset( $args['options'] ) ) {
3905                                         unset( $args['options'] );
3906                                         wfDeprecated(
3907                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3908                                                 '1.20'
3909                                         );
3910                                 }
3911                         } else {
3912                                 $args = [];
3913                                 $name = $spec;
3914                         }
3915                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3916                 }
3917                 $this->addWikiText( $s );
3918         }
3919
3920         /**
3921          * Enables/disables TOC, doesn't override __NOTOC__
3922          * @param bool $flag
3923          * @since 1.22
3924          */
3925         public function enableTOC( $flag = true ) {
3926                 $this->mEnableTOC = $flag;
3927         }
3928
3929         /**
3930          * @return bool
3931          * @since 1.22
3932          */
3933         public function isTOCEnabled() {
3934                 return $this->mEnableTOC;
3935         }
3936
3937         /**
3938          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3939          * @param bool $flag
3940          * @since 1.23
3941          */
3942         public function enableSectionEditLinks( $flag = true ) {
3943                 $this->mEnableSectionEditLinks = $flag;
3944         }
3945
3946         /**
3947          * @return bool
3948          * @since 1.23
3949          */
3950         public function sectionEditLinksEnabled() {
3951                 return $this->mEnableSectionEditLinks;
3952         }
3953
3954         /**
3955          * Helper function to setup the PHP implementation of OOUI to use in this request.
3956          *
3957          * @since 1.26
3958          * @param String $skinName The Skin name to determine the correct OOUI theme
3959          * @param String $dir Language direction
3960          */
3961         public static function setupOOUI( $skinName = '', $dir = 'ltr' ) {
3962                 $themes = ExtensionRegistry::getInstance()->getAttribute( 'SkinOOUIThemes' );
3963                 // Make keys (skin names) lowercase for case-insensitive matching.
3964                 $themes = array_change_key_case( $themes, CASE_LOWER );
3965                 $theme = isset( $themes[$skinName] ) ? $themes[$skinName] : 'MediaWiki';
3966                 // For example, 'OOUI\MediaWikiTheme'.
3967                 $themeClass = "OOUI\\{$theme}Theme";
3968                 OOUI\Theme::setSingleton( new $themeClass() );
3969                 OOUI\Element::setDefaultDir( $dir );
3970         }
3971
3972         /**
3973          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3974          * MediaWiki and this OutputPage instance.
3975          *
3976          * @since 1.25
3977          */
3978         public function enableOOUI() {
3979                 self::setupOOUI(
3980                         strtolower( $this->getSkin()->getSkinName() ),
3981                         $this->getLanguage()->getDir()
3982                 );
3983                 $this->addModuleStyles( [
3984                         'oojs-ui-core.styles',
3985                         'oojs-ui.styles.icons',
3986                         'oojs-ui.styles.indicators',
3987                         'oojs-ui.styles.textures',
3988                         'mediawiki.widgets.styles',
3989                 ] );
3990         }
3991
3992         /**
3993          * Add Link headers for preloading the wiki's logo.
3994          *
3995          * @since 1.26
3996          */
3997         protected function addLogoPreloadLinkHeaders() {
3998                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
3999
4000                 $tags = [];
4001                 $logosPerDppx = [];
4002                 $logos = [];
4003
4004                 if ( !is_array( $logo ) ) {
4005                         // No media queries required if we only have one variant
4006                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
4007                         return;
4008                 }
4009
4010                 foreach ( $logo as $dppx => $src ) {
4011                         // Keys are in this format: "1.5x"
4012                         $dppx = substr( $dppx, 0, -1 );
4013                         $logosPerDppx[$dppx] = $src;
4014                 }
4015
4016                 // Because PHP can't have floats as array keys
4017                 uksort( $logosPerDppx, function ( $a , $b ) {
4018                         $a = floatval( $a );
4019                         $b = floatval( $b );
4020
4021                         if ( $a == $b ) {
4022                                 return 0;
4023                         }
4024                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
4025                         return ( $a < $b ) ? -1 : 1;
4026                 } );
4027
4028                 foreach ( $logosPerDppx as $dppx => $src ) {
4029                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
4030                 }
4031
4032                 $logosCount = count( $logos );
4033                 // Logic must match ResourceLoaderSkinModule:
4034                 // - 1x applies to resolution < 1.5dppx
4035                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
4036                 // - 2x applies to resolution >= 2dppx
4037                 // Note that min-resolution and max-resolution are both inclusive.
4038                 for ( $i = 0; $i < $logosCount; $i++ ) {
4039                         if ( $i === 0 ) {
4040                                 // Smallest dppx
4041                                 // min-resolution is ">=" (larger than or equal to)
4042                                 // "not min-resolution" is essentially "<"
4043                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
4044                         } elseif ( $i !== $logosCount - 1 ) {
4045                                 // In between
4046                                 // Media query expressions can only apply "not" to the entire expression
4047                                 // (e.g. can't express ">= 1.5 and not >= 2).
4048                                 // Workaround: Use <= 1.9999 in place of < 2.
4049                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
4050                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
4051                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
4052                         } else {
4053                                 // Largest dppx
4054                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
4055                         }
4056
4057                         $this->addLinkHeader(
4058                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
4059                         );
4060                 }
4061         }
4062 }