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 Additional <body> classes; there are also <body> classes from other sources */
 143         protected $mAdditionalBodyClasses = [];
 144
 145         /** @var array */
 146         protected $mModules = [];
 147
 148         /** @var array */
 149         protected $mModuleScripts = [];
 150
 151         /** @var array */
 152         protected $mModuleStyles = [];
 153
 154         /** @var ResourceLoader */
 155         protected $mResourceLoader;
 156
 157         /** @var ResourceLoaderClientHtml */
 158         private $rlClient;
 159
 160         /** @var ResourceLoaderContext */
 161         private $rlClientContext;
 162
 163         /** @var string */
 164         private $rlUserModuleState;
 165
 166         /** @var array */
 167         private $rlExemptStyleModules;
 168
 169         /** @var array */
 170         protected $mJsConfigVars = [];
 171
 172         /** @var array */
 173         protected $mTemplateIds = [];
 174
 175         /** @var array */
 176         protected $mImageTimeKeys = [];
 177
 178         /** @var string */
 179         public $mRedirectCode = '';
 180
 181         protected $mFeedLinksAppendQuery = null;
 182
 183         /** @var array
 184          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 185          * @see ResourceLoaderModule::$origin
 186          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 187          */
 188         protected $mAllowedModules = [
 189                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 190         ];
 191
 192         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 193         protected $mDoNothing = false;
 194
 195         // Parser related.
 196
 197         /** @var int */
 198         protected $mContainsNewMagic = 0;
 199
 200         /**
 201          * lazy initialised, use parserOptions()
 202          * @var ParserOptions
 203          */
 204         protected $mParserOptions = null;
 205
 206         /**
 207          * Handles the Atom / RSS links.
 208          * We probably only support Atom in 2011.
 209          * @see $wgAdvertisedFeedTypes
 210          */
 211         private $mFeedLinks = [];
 212
 213         // Gwicke work on squid caching? Roughly from 2003.
 214         protected $mEnableClientCache = true;
 215
 216         /** @var bool Flag if output should only contain the body of the article. */
 217         private $mArticleBodyOnly = false;
 218
 219         /** @var bool */
 220         protected $mNewSectionLink = false;
 221
 222         /** @var bool */
 223         protected $mHideNewSectionLink = false;
 224
 225         /**
 226          * @var bool Comes from the parser. This was probably made to load CSS/JS
 227          * only if we had "<gallery>". Used directly in CategoryPage.php.
 228          * Looks like ResourceLoader can replace this.
 229          */
 230         public $mNoGallery = false;
 231
 232         /** @var string */
 233         private $mPageTitleActionText = '';
 234
 235         /** @var int Cache stuff. Looks like mEnableClientCache */
 236         protected $mCdnMaxage = 0;
 237         /** @var int Upper limit on mCdnMaxage */
 238         protected $mCdnMaxageLimit = INF;
 239
 240         /**
 241          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 242          * be sent. This should be done for pages where edit actions are possible.
 243          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 244          */
 245         protected $mPreventClickjacking = true;
 246
 247         /** @var int To include the variable {{REVISIONID}} */
 248         private $mRevisionId = null;
 249
 250         /** @var string */
 251         private $mRevisionTimestamp = null;
 252
 253         /** @var array */
 254         protected $mFileVersion = null;
 255
 256         /**
 257          * @var array An array of stylesheet filenames (relative from skins path),
 258          * with options for CSS media, IE conditions, and RTL/LTR direction.
 259          * For internal use; add settings in the skin via $this->addStyle()
 260          *
 261          * Style again! This seems like a code duplication since we already have
 262          * mStyles. This is what makes Open Source amazing.
 263          */
 264         protected $styles = [];
 265
 266         private $mIndexPolicy = 'index';
 267         private $mFollowPolicy = 'follow';
 268         private $mVaryHeader = [
 269                 'Accept-Encoding' => [ 'match=gzip' ],
 270         ];
 271
 272         /**
 273          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 274          * of the redirect.
 275          *
 276          * @var Title
 277          */
 278         private $mRedirectedFrom = null;
 279
 280         /**
 281          * Additional key => value data
 282          */
 283         private $mProperties = [];
 284
 285         /**
 286          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 287          */
 288         private $mTarget = null;
 289
 290         /**
 291          * @var bool Whether parser output contains a table of contents
 292          */
 293         private $mEnableTOC = false;
 294
 295         /**
 296          * @var bool Whether parser output should contain section edit links
 297          */
 298         private $mEnableSectionEditLinks = true;
 299
 300         /**
 301          * @var string|null The URL to send in a <link> element with rel=license
 302          */
 303         private $copyrightUrl;
 304
 305         /** @var array Profiling data */
 306         private $limitReportJSData = [];
 307
 308         /**
 309          * Link: header contents
 310          */
 311         private $mLinkHeader = [];
 312
 313         /**
 314          * Constructor for OutputPage. This should not be called directly.
 315          * Instead a new RequestContext should be created and it will implicitly create
 316          * a OutputPage tied to that context.
 317          * @param IContextSource $context
 318          */
 319         function __construct( IContextSource $context ) {
 320                 $this->setContext( $context );
 321         }
 322
 323         /**
 324          * Redirect to $url rather than displaying the normal page
 325          *
 326          * @param string $url URL
 327          * @param string $responsecode HTTP status code
 328          */
 329         public function redirect( $url, $responsecode = '302' ) {
 330                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 331                 $this->mRedirect = str_replace( "\n", '', $url );
 332                 $this->mRedirectCode = $responsecode;
 333         }
 334
 335         /**
 336          * Get the URL to redirect to, or an empty string if not redirect URL set
 337          *
 338          * @return string
 339          */
 340         public function getRedirect() {
 341                 return $this->mRedirect;
 342         }
 343
 344         /**
 345          * Set the copyright URL to send with the output.
 346          * Empty string to omit, null to reset.
 347          *
 348          * @since 1.26
 349          *
 350          * @param string|null $url
 351          */
 352         public function setCopyrightUrl( $url ) {
 353                 $this->copyrightUrl = $url;
 354         }
 355
 356         /**
 357          * Set the HTTP status code to send with the output.
 358          *
 359          * @param int $statusCode
 360          */
 361         public function setStatusCode( $statusCode ) {
 362                 $this->mStatusCode = $statusCode;
 363         }
 364
 365         /**
 366          * Add a new "<meta>" tag
 367          * To add an http-equiv meta tag, precede the name with "http:"
 368          *
 369          * @param string $name Tag name
 370          * @param string $val Tag value
 371          */
 372         function addMeta( $name, $val ) {
 373                 array_push( $this->mMetatags, [ $name, $val ] );
 374         }
 375
 376         /**
 377          * Returns the current <meta> tags
 378          *
 379          * @since 1.25
 380          * @return array
 381          */
 382         public function getMetaTags() {
 383                 return $this->mMetatags;
 384         }
 385
 386         /**
 387          * Add a new \<link\> tag to the page header.
 388          *
 389          * Note: use setCanonicalUrl() for rel=canonical.
 390          *
 391          * @param array $linkarr Associative array of attributes.
 392          */
 393         function addLink( array $linkarr ) {
 394                 array_push( $this->mLinktags, $linkarr );
 395         }
 396
 397         /**
 398          * Returns the current <link> tags
 399          *
 400          * @since 1.25
 401          * @return array
 402          */
 403         public function getLinkTags() {
 404                 return $this->mLinktags;
 405         }
 406
 407         /**
 408          * Add a new \<link\> with "rel" attribute set to "meta"
 409          *
 410          * @param array $linkarr Associative array mapping attribute names to their
 411          *                 values, both keys and values will be escaped, and the
 412          *                 "rel" attribute will be automatically added
 413          */
 414         function addMetadataLink( array $linkarr ) {
 415                 $linkarr['rel'] = $this->getMetadataAttribute();
 416                 $this->addLink( $linkarr );
 417         }
 418
 419         /**
 420          * Set the URL to be used for the <link rel=canonical>. This should be used
 421          * in preference to addLink(), to avoid duplicate link tags.
 422          * @param string $url
 423          */
 424         function setCanonicalUrl( $url ) {
 425                 $this->mCanonicalUrl = $url;
 426         }
 427
 428         /**
 429          * Returns the URL to be used for the <link rel=canonical> if
 430          * one is set.
 431          *
 432          * @since 1.25
 433          * @return bool|string
 434          */
 435         public function getCanonicalUrl() {
 436                 return $this->mCanonicalUrl;
 437         }
 438
 439         /**
 440          * Get the value of the "rel" attribute for metadata links
 441          *
 442          * @return string
 443          */
 444         public function getMetadataAttribute() {
 445                 # note: buggy CC software only reads first "meta" link
 446                 static $haveMeta = false;
 447                 if ( $haveMeta ) {
 448                         return 'alternate meta';
 449                 } else {
 450                         $haveMeta = true;
 451                         return 'meta';
 452                 }
 453         }
 454
 455         /**
 456          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 457          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 458          * if possible.
 459          *
 460          * @param string $script Raw HTML
 461          */
 462         function addScript( $script ) {
 463                 $this->mScripts .= $script;
 464         }
 465
 466         /**
 467          * Register and add a stylesheet from an extension directory.
 468          *
 469          * @deprecated since 1.27 use addModuleStyles() or addStyle() instead
 470          * @param string $url Path to sheet.  Provide either a full url (beginning
 471          *             with 'http', etc) or a relative path from the document root
 472          *             (beginning with '/').  Otherwise it behaves identically to
 473          *             addStyle() and draws from the /skins folder.
 474          */
 475         public function addExtensionStyle( $url ) {
 476                 wfDeprecated( __METHOD__, '1.27' );
 477                 array_push( $this->mExtStyles, $url );
 478         }
 479
 480         /**
 481          * Get all styles added by extensions
 482          *
 483          * @deprecated since 1.27
 484          * @return array
 485          */
 486         function getExtStyle() {
 487                 wfDeprecated( __METHOD__, '1.27' );
 488                 return $this->mExtStyles;
 489         }
 490
 491         /**
 492          * Add a JavaScript file out of skins/common, or a given relative path.
 493          * Internal use only. Use OutputPage::addModules() if possible.
 494          *
 495          * @param string $file Filename in skins/common or complete on-server path
 496          *              (/foo/bar.js)
 497          * @param string $version Style version of the file. Defaults to $wgStyleVersion
 498          */
 499         public function addScriptFile( $file, $version = null ) {
 500                 // See if $file parameter is an absolute URL or begins with a slash
 501                 if ( substr( $file, 0, 1 ) == '/' || preg_match( '#^[a-z]*://#i', $file ) ) {
 502                         $path = $file;
 503                 } else {
 504                         $path = $this->getConfig()->get( 'StylePath' ) . "/common/{$file}";
 505                 }
 506                 if ( is_null( $version ) ) {
 507                         $version = $this->getConfig()->get( 'StyleVersion' );
 508                 }
 509                 $this->addScript( Html::linkedScript( wfAppendQuery( $path, $version ) ) );
 510         }
 511
 512         /**
 513          * Add a self-contained script tag with the given contents
 514          * Internal use only. Use OutputPage::addModules() if possible.
 515          *
 516          * @param string $script JavaScript text, no script tags
 517          */
 518         public function addInlineScript( $script ) {
 519                 $this->mScripts .= Html::inlineScript( $script );
 520         }
 521
 522         /**
 523          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 524          * which are no longer registered (eg a page is cached before an extension is disabled)
 525          * @param array $modules
 526          * @param string|null $position If not null, only return modules with this position
 527          * @param string $type
 528          * @return array
 529          */
 530         protected function filterModules( array $modules, $position = null,
 531                 $type = ResourceLoaderModule::TYPE_COMBINED
 532         ) {
 533                 $resourceLoader = $this->getResourceLoader();
 534                 $filteredModules = [];
 535                 foreach ( $modules as $val ) {
 536                         $module = $resourceLoader->getModule( $val );
 537                         if ( $module instanceof ResourceLoaderModule
 538                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 539                                 && ( is_null( $position ) || $module->getPosition() == $position )
 540                         ) {
 541                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 542                                         $this->warnModuleTargetFilter( $module->getName() );
 543                                         continue;
 544                                 }
 545                                 $filteredModules[] = $val;
 546                         }
 547                 }
 548                 return $filteredModules;
 549         }
 550
 551         private function warnModuleTargetFilter( $moduleName ) {
 552                 static $warnings = [];
 553                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 554                         return;
 555                 }
 556                 $warnings[$this->mTarget][$moduleName] = true;
 557                 $this->getResourceLoader()->getLogger()->debug(
 558                         'Module "{module}" not loadable on target "{target}".',
 559                         [
 560                                 'module' => $moduleName,
 561                                 'target' => $this->mTarget,
 562                         ]
 563                 );
 564         }
 565
 566         /**
 567          * Get the list of modules to include on this page
 568          *
 569          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 570          * @param string|null $position If not null, only return modules with this position
 571          * @param string $param
 572          * @param string $type
 573          * @return array Array of module names
 574          */
 575         public function getModules( $filter = false, $position = null, $param = 'mModules',
 576                 $type = ResourceLoaderModule::TYPE_COMBINED
 577         ) {
 578                 $modules = array_values( array_unique( $this->$param ) );
 579                 return $filter
 580                         ? $this->filterModules( $modules, $position, $type )
 581                         : $modules;
 582         }
 583
 584         /**
 585          * Add one or more modules recognized by ResourceLoader. Modules added
 586          * through this function will be loaded by ResourceLoader when the
 587          * page loads.
 588          *
 589          * @param string|array $modules Module name (string) or array of module names
 590          */
 591         public function addModules( $modules ) {
 592                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 593         }
 594
 595         /**
 596          * Get the list of module JS to include on this page
 597          *
 598          * @param bool $filter
 599          * @param string|null $position
 600          * @return array Array of module names
 601          */
 602         public function getModuleScripts( $filter = false, $position = null ) {
 603                 return $this->getModules( $filter, $position, 'mModuleScripts',
 604                         ResourceLoaderModule::TYPE_SCRIPTS
 605                 );
 606         }
 607
 608         /**
 609          * Add only JS of one or more modules recognized by ResourceLoader. Module
 610          * scripts added through this function will be loaded by ResourceLoader when
 611          * the page loads.
 612          *
 613          * @param string|array $modules Module name (string) or array of module names
 614          */
 615         public function addModuleScripts( $modules ) {
 616                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 617         }
 618
 619         /**
 620          * Get the list of module CSS to include on this page
 621          *
 622          * @param bool $filter
 623          * @param string|null $position
 624          * @return array Array of module names
 625          */
 626         public function getModuleStyles( $filter = false, $position = null ) {
 627                 return $this->getModules( $filter, $position, 'mModuleStyles',
 628                         ResourceLoaderModule::TYPE_STYLES
 629                 );
 630         }
 631
 632         /**
 633          * Add only CSS of one or more modules recognized by ResourceLoader.
 634          *
 635          * Module styles added through this function will be added using standard link CSS
 636          * tags, rather than as a combined Javascript and CSS package. Thus, they will
 637          * load when JavaScript is disabled (unless CSS also happens to be disabled).
 638          *
 639          * @param string|array $modules Module name (string) or array of module names
 640          */
 641         public function addModuleStyles( $modules ) {
 642                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 643         }
 644
 645         /**
 646          * @return null|string ResourceLoader target
 647          */
 648         public function getTarget() {
 649                 return $this->mTarget;
 650         }
 651
 652         /**
 653          * Sets ResourceLoader target for load.php links. If null, will be omitted
 654          *
 655          * @param string|null $target
 656          */
 657         public function setTarget( $target ) {
 658                 $this->mTarget = $target;
 659         }
 660
 661         /**
 662          * Get an array of head items
 663          *
 664          * @return array
 665          */
 666         function getHeadItemsArray() {
 667                 return $this->mHeadItems;
 668         }
 669
 670         /**
 671          * Add or replace a head item to the output
 672          *
 673          * Whenever possible, use more specific options like ResourceLoader modules,
 674          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 675          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 676          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 677          * This would be your very LAST fallback.
 678          *
 679          * @param string $name Item name
 680          * @param string $value Raw HTML
 681          */
 682         public function addHeadItem( $name, $value ) {
 683                 $this->mHeadItems[$name] = $value;
 684         }
 685
 686         /**
 687          * Add one or more head items to the output
 688          *
 689          * @since 1.28
 690          * @param string|string[] $values Raw HTML
 691          */
 692         public function addHeadItems( $values ) {
 693                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 694         }
 695
 696         /**
 697          * Check if the header item $name is already set
 698          *
 699          * @param string $name Item name
 700          * @return bool
 701          */
 702         public function hasHeadItem( $name ) {
 703                 return isset( $this->mHeadItems[$name] );
 704         }
 705
 706         /**
 707          * Add a class to the <body> element
 708          *
 709          * @since 1.30
 710          * @param string|string[] $classes One or more classes to add
 711          */
 712         public function addBodyClasses( $classes ) {
 713                 $this->mAdditionalBodyClasses = array_merge( $this->mAdditionalBodyClasses, (array)$classes );
 714         }
 715
 716         /**
 717          * @deprecated since 1.28 Obsolete - wgUseETag experiment was removed.
 718          * @param string $tag
 719          */
 720         public function setETag( $tag ) {
 721         }
 722
 723         /**
 724          * Set whether the output should only contain the body of the article,
 725          * without any skin, sidebar, etc.
 726          * Used e.g. when calling with "action=render".
 727          *
 728          * @param bool $only Whether to output only the body of the article
 729          */
 730         public function setArticleBodyOnly( $only ) {
 731                 $this->mArticleBodyOnly = $only;
 732         }
 733
 734         /**
 735          * Return whether the output will contain only the body of the article
 736          *
 737          * @return bool
 738          */
 739         public function getArticleBodyOnly() {
 740                 return $this->mArticleBodyOnly;
 741         }
 742
 743         /**
 744          * Set an additional output property
 745          * @since 1.21
 746          *
 747          * @param string $name
 748          * @param mixed $value
 749          */
 750         public function setProperty( $name, $value ) {
 751                 $this->mProperties[$name] = $value;
 752         }
 753
 754         /**
 755          * Get an additional output property
 756          * @since 1.21
 757          *
 758          * @param string $name
 759          * @return mixed Property value or null if not found
 760          */
 761         public function getProperty( $name ) {
 762                 if ( isset( $this->mProperties[$name] ) ) {
 763                         return $this->mProperties[$name];
 764                 } else {
 765                         return null;
 766                 }
 767         }
 768
 769         /**
 770          * checkLastModified tells the client to use the client-cached page if
 771          * possible. If successful, the OutputPage is disabled so that
 772          * any future call to OutputPage->output() have no effect.
 773          *
 774          * Side effect: sets mLastModified for Last-Modified header
 775          *
 776          * @param string $timestamp
 777          *
 778          * @return bool True if cache-ok headers was sent.
 779          */
 780         public function checkLastModified( $timestamp ) {
 781                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 782                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 783                         return false;
 784                 }
 785                 $config = $this->getConfig();
 786                 if ( !$config->get( 'CachePages' ) ) {
 787                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 788                         return false;
 789                 }
 790
 791                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 792                 $modifiedTimes = [
 793                         'page' => $timestamp,
 794                         'user' => $this->getUser()->getTouched(),
 795                         'epoch' => $config->get( 'CacheEpoch' )
 796                 ];
 797                 if ( $config->get( 'UseSquid' ) ) {
 798                         // T46570: the core page itself may not change, but resources might
 799                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, time() - $config->get( 'SquidMaxage' ) );
 800                 }
 801                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 802
 803                 $maxModified = max( $modifiedTimes );
 804                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 805
 806                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 807                 if ( $clientHeader === false ) {
 808                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 809                         return false;
 810                 }
 811
 812                 # IE sends sizes after the date like this:
 813                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 814                 # this breaks strtotime().
 815                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 816
 817                 MediaWiki\suppressWarnings(); // E_STRICT system time bitching
 818                 $clientHeaderTime = strtotime( $clientHeader );
 819                 MediaWiki\restoreWarnings();
 820                 if ( !$clientHeaderTime ) {
 821                         wfDebug( __METHOD__
 822                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 823                         return false;
 824                 }
 825                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 826
 827                 # Make debug info
 828                 $info = '';
 829                 foreach ( $modifiedTimes as $name => $value ) {
 830                         if ( $info !== '' ) {
 831                                 $info .= ', ';
 832                         }
 833                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 834                 }
 835
 836                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 837                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 838                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 839                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 840                 if ( $clientHeaderTime < $maxModified ) {
 841                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 842                         return false;
 843                 }
 844
 845                 # Not modified
 846                 # Give a 304 Not Modified response code and disable body output
 847                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 848                 ini_set( 'zlib.output_compression', 0 );
 849                 $this->getRequest()->response()->statusHeader( 304 );
 850                 $this->sendCacheControl();
 851                 $this->disable();
 852
 853                 // Don't output a compressed blob when using ob_gzhandler;
 854                 // it's technically against HTTP spec and seems to confuse
 855                 // Firefox when the response gets split over two packets.
 856                 wfClearOutputBuffers();
 857
 858                 return true;
 859         }
 860
 861         /**
 862          * Override the last modified timestamp
 863          *
 864          * @param string $timestamp New timestamp, in a format readable by
 865          *        wfTimestamp()
 866          */
 867         public function setLastModified( $timestamp ) {
 868                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 869         }
 870
 871         /**
 872          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 873          *
 874          * @param string $policy The literal string to output as the contents of
 875          *   the meta tag.  Will be parsed according to the spec and output in
 876          *   standardized form.
 877          * @return null
 878          */
 879         public function setRobotPolicy( $policy ) {
 880                 $policy = Article::formatRobotPolicy( $policy );
 881
 882                 if ( isset( $policy['index'] ) ) {
 883                         $this->setIndexPolicy( $policy['index'] );
 884                 }
 885                 if ( isset( $policy['follow'] ) ) {
 886                         $this->setFollowPolicy( $policy['follow'] );
 887                 }
 888         }
 889
 890         /**
 891          * Set the index policy for the page, but leave the follow policy un-
 892          * touched.
 893          *
 894          * @param string $policy Either 'index' or 'noindex'.
 895          * @return null
 896          */
 897         public function setIndexPolicy( $policy ) {
 898                 $policy = trim( $policy );
 899                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 900                         $this->mIndexPolicy = $policy;
 901                 }
 902         }
 903
 904         /**
 905          * Set the follow policy for the page, but leave the index policy un-
 906          * touched.
 907          *
 908          * @param string $policy Either 'follow' or 'nofollow'.
 909          * @return null
 910          */
 911         public function setFollowPolicy( $policy ) {
 912                 $policy = trim( $policy );
 913                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 914                         $this->mFollowPolicy = $policy;
 915                 }
 916         }
 917
 918         /**
 919          * Set the new value of the "action text", this will be added to the
 920          * "HTML title", separated from it with " - ".
 921          *
 922          * @param string $text New value of the "action text"
 923          */
 924         public function setPageTitleActionText( $text ) {
 925                 $this->mPageTitleActionText = $text;
 926         }
 927
 928         /**
 929          * Get the value of the "action text"
 930          *
 931          * @return string
 932          */
 933         public function getPageTitleActionText() {
 934                 return $this->mPageTitleActionText;
 935         }
 936
 937         /**
 938          * "HTML title" means the contents of "<title>".
 939          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 940          *
 941          * @param string|Message $name
 942          */
 943         public function setHTMLTitle( $name ) {
 944                 if ( $name instanceof Message ) {
 945                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 946                 } else {
 947                         $this->mHTMLtitle = $name;
 948                 }
 949         }
 950
 951         /**
 952          * Return the "HTML title", i.e. the content of the "<title>" tag.
 953          *
 954          * @return string
 955          */
 956         public function getHTMLTitle() {
 957                 return $this->mHTMLtitle;
 958         }
 959
 960         /**
 961          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 962          *
 963          * @param Title $t
 964          */
 965         public function setRedirectedFrom( $t ) {
 966                 $this->mRedirectedFrom = $t;
 967         }
 968
 969         /**
 970          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 971          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 972          * but not bad tags like \<script\>. This function automatically sets
 973          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 974          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 975          * good tags like \<i\> will be dropped entirely.
 976          *
 977          * @param string|Message $name
 978          */
 979         public function setPageTitle( $name ) {
 980                 if ( $name instanceof Message ) {
 981                         $name = $name->setContext( $this->getContext() )->text();
 982                 }
 983
 984                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 985                 # but leave "<i>foobar</i>" alone
 986                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 987                 $this->mPagetitle = $nameWithTags;
 988
 989                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 990                 $this->setHTMLTitle(
 991                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 992                                 ->inContentLanguage()
 993                 );
 994         }
 995
 996         /**
 997          * Return the "page title", i.e. the content of the \<h1\> tag.
 998          *
 999          * @return string
1000          */
1001         public function getPageTitle() {
1002                 return $this->mPagetitle;
1003         }
1004
1005         /**
1006          * Set the Title object to use
1007          *
1008          * @param Title $t
1009          */
1010         public function setTitle( Title $t ) {
1011                 $this->getContext()->setTitle( $t );
1012         }
1013
1014         /**
1015          * Replace the subtitle with $str
1016          *
1017          * @param string|Message $str New value of the subtitle. String should be safe HTML.
1018          */
1019         public function setSubtitle( $str ) {
1020                 $this->clearSubtitle();
1021                 $this->addSubtitle( $str );
1022         }
1023
1024         /**
1025          * Add $str to the subtitle
1026          *
1027          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
1028          */
1029         public function addSubtitle( $str ) {
1030                 if ( $str instanceof Message ) {
1031                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
1032                 } else {
1033                         $this->mSubtitle[] = $str;
1034                 }
1035         }
1036
1037         /**
1038          * Build message object for a subtitle containing a backlink to a page
1039          *
1040          * @param Title $title Title to link to
1041          * @param array $query Array of additional parameters to include in the link
1042          * @return Message
1043          * @since 1.25
1044          */
1045         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1046                 if ( $title->isRedirect() ) {
1047                         $query['redirect'] = 'no';
1048                 }
1049                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1050                 return wfMessage( 'backlinksubtitle' )
1051                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1052         }
1053
1054         /**
1055          * Add a subtitle containing a backlink to a page
1056          *
1057          * @param Title $title Title to link to
1058          * @param array $query Array of additional parameters to include in the link
1059          */
1060         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1061                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1062         }
1063
1064         /**
1065          * Clear the subtitles
1066          */
1067         public function clearSubtitle() {
1068                 $this->mSubtitle = [];
1069         }
1070
1071         /**
1072          * Get the subtitle
1073          *
1074          * @return string
1075          */
1076         public function getSubtitle() {
1077                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1078         }
1079
1080         /**
1081          * Set the page as printable, i.e. it'll be displayed with all
1082          * print styles included
1083          */
1084         public function setPrintable() {
1085                 $this->mPrintable = true;
1086         }
1087
1088         /**
1089          * Return whether the page is "printable"
1090          *
1091          * @return bool
1092          */
1093         public function isPrintable() {
1094                 return $this->mPrintable;
1095         }
1096
1097         /**
1098          * Disable output completely, i.e. calling output() will have no effect
1099          */
1100         public function disable() {
1101                 $this->mDoNothing = true;
1102         }
1103
1104         /**
1105          * Return whether the output will be completely disabled
1106          *
1107          * @return bool
1108          */
1109         public function isDisabled() {
1110                 return $this->mDoNothing;
1111         }
1112
1113         /**
1114          * Show an "add new section" link?
1115          *
1116          * @return bool
1117          */
1118         public function showNewSectionLink() {
1119                 return $this->mNewSectionLink;
1120         }
1121
1122         /**
1123          * Forcibly hide the new section link?
1124          *
1125          * @return bool
1126          */
1127         public function forceHideNewSectionLink() {
1128                 return $this->mHideNewSectionLink;
1129         }
1130
1131         /**
1132          * Add or remove feed links in the page header
1133          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1134          * for the new version
1135          * @see addFeedLink()
1136          *
1137          * @param bool $show True: add default feeds, false: remove all feeds
1138          */
1139         public function setSyndicated( $show = true ) {
1140                 if ( $show ) {
1141                         $this->setFeedAppendQuery( false );
1142                 } else {
1143                         $this->mFeedLinks = [];
1144                 }
1145         }
1146
1147         /**
1148          * Add default feeds to the page header
1149          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1150          * for the new version
1151          * @see addFeedLink()
1152          *
1153          * @param string $val Query to append to feed links or false to output
1154          *        default links
1155          */
1156         public function setFeedAppendQuery( $val ) {
1157                 $this->mFeedLinks = [];
1158
1159                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1160                         $query = "feed=$type";
1161                         if ( is_string( $val ) ) {
1162                                 $query .= '&' . $val;
1163                         }
1164                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1165                 }
1166         }
1167
1168         /**
1169          * Add a feed link to the page header
1170          *
1171          * @param string $format Feed type, should be a key of $wgFeedClasses
1172          * @param string $href URL
1173          */
1174         public function addFeedLink( $format, $href ) {
1175                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1176                         $this->mFeedLinks[$format] = $href;
1177                 }
1178         }
1179
1180         /**
1181          * Should we output feed links for this page?
1182          * @return bool
1183          */
1184         public function isSyndicated() {
1185                 return count( $this->mFeedLinks ) > 0;
1186         }
1187
1188         /**
1189          * Return URLs for each supported syndication format for this page.
1190          * @return array Associating format keys with URLs
1191          */
1192         public function getSyndicationLinks() {
1193                 return $this->mFeedLinks;
1194         }
1195
1196         /**
1197          * Will currently always return null
1198          *
1199          * @return null
1200          */
1201         public function getFeedAppendQuery() {
1202                 return $this->mFeedLinksAppendQuery;
1203         }
1204
1205         /**
1206          * Set whether the displayed content is related to the source of the
1207          * corresponding article on the wiki
1208          * Setting true will cause the change "article related" toggle to true
1209          *
1210          * @param bool $v
1211          */
1212         public function setArticleFlag( $v ) {
1213                 $this->mIsarticle = $v;
1214                 if ( $v ) {
1215                         $this->mIsArticleRelated = $v;
1216                 }
1217         }
1218
1219         /**
1220          * Return whether the content displayed page is related to the source of
1221          * the corresponding article on the wiki
1222          *
1223          * @return bool
1224          */
1225         public function isArticle() {
1226                 return $this->mIsarticle;
1227         }
1228
1229         /**
1230          * Set whether this page is related an article on the wiki
1231          * Setting false will cause the change of "article flag" toggle to false
1232          *
1233          * @param bool $v
1234          */
1235         public function setArticleRelated( $v ) {
1236                 $this->mIsArticleRelated = $v;
1237                 if ( !$v ) {
1238                         $this->mIsarticle = false;
1239                 }
1240         }
1241
1242         /**
1243          * Return whether this page is related an article on the wiki
1244          *
1245          * @return bool
1246          */
1247         public function isArticleRelated() {
1248                 return $this->mIsArticleRelated;
1249         }
1250
1251         /**
1252          * Add new language links
1253          *
1254          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1255          *                               (e.g. 'fr:Test page')
1256          */
1257         public function addLanguageLinks( array $newLinkArray ) {
1258                 $this->mLanguageLinks += $newLinkArray;
1259         }
1260
1261         /**
1262          * Reset the language links and add new language links
1263          *
1264          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1265          *                               (e.g. 'fr:Test page')
1266          */
1267         public function setLanguageLinks( array $newLinkArray ) {
1268                 $this->mLanguageLinks = $newLinkArray;
1269         }
1270
1271         /**
1272          * Get the list of language links
1273          *
1274          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1275          */
1276         public function getLanguageLinks() {
1277                 return $this->mLanguageLinks;
1278         }
1279
1280         /**
1281          * Add an array of categories, with names in the keys
1282          *
1283          * @param array $categories Mapping category name => sort key
1284          */
1285         public function addCategoryLinks( array $categories ) {
1286                 global $wgContLang;
1287
1288                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1289                         return;
1290                 }
1291
1292                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1293
1294                 # Set all the values to 'normal'.
1295                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1296
1297                 # Mark hidden categories
1298                 foreach ( $res as $row ) {
1299                         if ( isset( $row->pp_value ) ) {
1300                                 $categories[$row->page_title] = 'hidden';
1301                         }
1302                 }
1303
1304                 // Avoid PHP 7.1 warning of passing $this by reference
1305                 $outputPage = $this;
1306                 # Add the remaining categories to the skin
1307                 if ( Hooks::run(
1308                         'OutputPageMakeCategoryLinks',
1309                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1310                 ) {
1311                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1312                         foreach ( $categories as $category => $type ) {
1313                                 // array keys will cast numeric category names to ints, so cast back to string
1314                                 $category = (string)$category;
1315                                 $origcategory = $category;
1316                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1317                                 if ( !$title ) {
1318                                         continue;
1319                                 }
1320                                 $wgContLang->findVariantLink( $category, $title, true );
1321                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1322                                         continue;
1323                                 }
1324                                 $text = $wgContLang->convertHtml( $title->getText() );
1325                                 $this->mCategories[$type][] = $title->getText();
1326                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1327                         }
1328                 }
1329         }
1330
1331         /**
1332          * @param array $categories
1333          * @return bool|ResultWrapper
1334          */
1335         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1336                 # Add the links to a LinkBatch
1337                 $arr = [ NS_CATEGORY => $categories ];
1338                 $lb = new LinkBatch;
1339                 $lb->setArray( $arr );
1340
1341                 # Fetch existence plus the hiddencat property
1342                 $dbr = wfGetDB( DB_REPLICA );
1343                 $fields = array_merge(
1344                         LinkCache::getSelectFields(),
1345                         [ 'page_namespace', 'page_title', 'pp_value' ]
1346                 );
1347
1348                 $res = $dbr->select( [ 'page', 'page_props' ],
1349                         $fields,
1350                         $lb->constructSet( 'page', $dbr ),
1351                         __METHOD__,
1352                         [],
1353                         [ 'page_props' => [ 'LEFT JOIN', [
1354                                 'pp_propname' => 'hiddencat',
1355                                 'pp_page = page_id'
1356                         ] ] ]
1357                 );
1358
1359                 # Add the results to the link cache
1360                 $lb->addResultToCache( LinkCache::singleton(), $res );
1361
1362                 return $res;
1363         }
1364
1365         /**
1366          * Reset the category links (but not the category list) and add $categories
1367          *
1368          * @param array $categories Mapping category name => sort key
1369          */
1370         public function setCategoryLinks( array $categories ) {
1371                 $this->mCategoryLinks = [];
1372                 $this->addCategoryLinks( $categories );
1373         }
1374
1375         /**
1376          * Get the list of category links, in a 2-D array with the following format:
1377          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1378          * hidden categories) and $link a HTML fragment with a link to the category
1379          * page
1380          *
1381          * @return array
1382          */
1383         public function getCategoryLinks() {
1384                 return $this->mCategoryLinks;
1385         }
1386
1387         /**
1388          * Get the list of category names this page belongs to.
1389          *
1390          * @param string $type The type of categories which should be returned. Possible values:
1391          *  * all: all categories of all types
1392          *  * hidden: only the hidden categories
1393          *  * normal: all categories, except hidden categories
1394          * @return array Array of strings
1395          */
1396         public function getCategories( $type = 'all' ) {
1397                 if ( $type === 'all' ) {
1398                         $allCategories = [];
1399                         foreach ( $this->mCategories as $categories ) {
1400                                 $allCategories = array_merge( $allCategories, $categories );
1401                         }
1402                         return $allCategories;
1403                 }
1404                 if ( !isset( $this->mCategories[$type] ) ) {
1405                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1406                 }
1407                 return $this->mCategories[$type];
1408         }
1409
1410         /**
1411          * Add an array of indicators, with their identifiers as array
1412          * keys and HTML contents as values.
1413          *
1414          * In case of duplicate keys, existing values are overwritten.
1415          *
1416          * @param array $indicators
1417          * @since 1.25
1418          */
1419         public function setIndicators( array $indicators ) {
1420                 $this->mIndicators = $indicators + $this->mIndicators;
1421                 // Keep ordered by key
1422                 ksort( $this->mIndicators );
1423         }
1424
1425         /**
1426          * Get the indicators associated with this page.
1427          *
1428          * The array will be internally ordered by item keys.
1429          *
1430          * @return array Keys: identifiers, values: HTML contents
1431          * @since 1.25
1432          */
1433         public function getIndicators() {
1434                 return $this->mIndicators;
1435         }
1436
1437         /**
1438          * Adds help link with an icon via page indicators.
1439          * Link target can be overridden by a local message containing a wikilink:
1440          * the message key is: lowercase action or special page name + '-helppage'.
1441          * @param string $to Target MediaWiki.org page title or encoded URL.
1442          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1443          * @since 1.25
1444          */
1445         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1446                 $this->addModuleStyles( 'mediawiki.helplink' );
1447                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1448
1449                 if ( $overrideBaseUrl ) {
1450                         $helpUrl = $to;
1451                 } else {
1452                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1453                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1454                 }
1455
1456                 $link = Html::rawElement(
1457                         'a',
1458                         [
1459                                 'href' => $helpUrl,
1460                                 'target' => '_blank',
1461                                 'class' => 'mw-helplink',
1462                         ],
1463                         $text
1464                 );
1465
1466                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1467         }
1468
1469         /**
1470          * Do not allow scripts which can be modified by wiki users to load on this page;
1471          * only allow scripts bundled with, or generated by, the software.
1472          * Site-wide styles are controlled by a config setting, since they can be
1473          * used to create a custom skin/theme, but not user-specific ones.
1474          *
1475          * @todo this should be given a more accurate name
1476          */
1477         public function disallowUserJs() {
1478                 $this->reduceAllowedModules(
1479                         ResourceLoaderModule::TYPE_SCRIPTS,
1480                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1481                 );
1482
1483                 // Site-wide styles are controlled by a config setting, see T73621
1484                 // for background on why. User styles are never allowed.
1485                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1486                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1487                 } else {
1488                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1489                 }
1490                 $this->reduceAllowedModules(
1491                         ResourceLoaderModule::TYPE_STYLES,
1492                         $styleOrigin
1493                 );
1494         }
1495
1496         /**
1497          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1498          * @see ResourceLoaderModule::$origin
1499          * @param string $type ResourceLoaderModule TYPE_ constant
1500          * @return int ResourceLoaderModule ORIGIN_ class constant
1501          */
1502         public function getAllowedModules( $type ) {
1503                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1504                         return min( array_values( $this->mAllowedModules ) );
1505                 } else {
1506                         return isset( $this->mAllowedModules[$type] )
1507                                 ? $this->mAllowedModules[$type]
1508                                 : ResourceLoaderModule::ORIGIN_ALL;
1509                 }
1510         }
1511
1512         /**
1513          * Limit the highest level of CSS/JS untrustworthiness allowed.
1514          *
1515          * If passed the same or a higher level than the current level of untrustworthiness set, the
1516          * level will remain unchanged.
1517          *
1518          * @param string $type
1519          * @param int $level ResourceLoaderModule class constant
1520          */
1521         public function reduceAllowedModules( $type, $level ) {
1522                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1523         }
1524
1525         /**
1526          * Prepend $text to the body HTML
1527          *
1528          * @param string $text HTML
1529          */
1530         public function prependHTML( $text ) {
1531                 $this->mBodytext = $text . $this->mBodytext;
1532         }
1533
1534         /**
1535          * Append $text to the body HTML
1536          *
1537          * @param string $text HTML
1538          */
1539         public function addHTML( $text ) {
1540                 $this->mBodytext .= $text;
1541         }
1542
1543         /**
1544          * Shortcut for adding an Html::element via addHTML.
1545          *
1546          * @since 1.19
1547          *
1548          * @param string $element
1549          * @param array $attribs
1550          * @param string $contents
1551          */
1552         public function addElement( $element, array $attribs = [], $contents = '' ) {
1553                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1554         }
1555
1556         /**
1557          * Clear the body HTML
1558          */
1559         public function clearHTML() {
1560                 $this->mBodytext = '';
1561         }
1562
1563         /**
1564          * Get the body HTML
1565          *
1566          * @return string HTML
1567          */
1568         public function getHTML() {
1569                 return $this->mBodytext;
1570         }
1571
1572         /**
1573          * Get/set the ParserOptions object to use for wikitext parsing
1574          *
1575          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1576          *   current ParserOption object
1577          * @return ParserOptions
1578          */
1579         public function parserOptions( $options = null ) {
1580                 if ( $options !== null && !empty( $options->isBogus ) ) {
1581                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1582                         // been changed somehow, and keep it if so.
1583                         $anonPO = ParserOptions::newFromAnon();
1584                         $anonPO->setEditSection( false );
1585                         $anonPO->setAllowUnsafeRawHtml( false );
1586                         if ( !$options->matches( $anonPO ) ) {
1587                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1588                                 $options->isBogus = false;
1589                         }
1590                 }
1591
1592                 if ( !$this->mParserOptions ) {
1593                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1594                                 // $wgUser isn't unstubbable yet, so don't try to get a
1595                                 // ParserOptions for it. And don't cache this ParserOptions
1596                                 // either.
1597                                 $po = ParserOptions::newFromAnon();
1598                                 $po->setEditSection( false );
1599                                 $po->setAllowUnsafeRawHtml( false );
1600                                 $po->isBogus = true;
1601                                 if ( $options !== null ) {
1602                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1603                                 }
1604                                 return $po;
1605                         }
1606
1607                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1608                         $this->mParserOptions->setEditSection( false );
1609                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1610                 }
1611
1612                 if ( $options !== null && !empty( $options->isBogus ) ) {
1613                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1614                         // thing.
1615                         return wfSetVar( $this->mParserOptions, null, true );
1616                 } else {
1617                         return wfSetVar( $this->mParserOptions, $options );
1618                 }
1619         }
1620
1621         /**
1622          * Set the revision ID which will be seen by the wiki text parser
1623          * for things such as embedded {{REVISIONID}} variable use.
1624          *
1625          * @param int|null $revid An positive integer, or null
1626          * @return mixed Previous value
1627          */
1628         public function setRevisionId( $revid ) {
1629                 $val = is_null( $revid ) ? null : intval( $revid );
1630                 return wfSetVar( $this->mRevisionId, $val );
1631         }
1632
1633         /**
1634          * Get the displayed revision ID
1635          *
1636          * @return int
1637          */
1638         public function getRevisionId() {
1639                 return $this->mRevisionId;
1640         }
1641
1642         /**
1643          * Set the timestamp of the revision which will be displayed. This is used
1644          * to avoid a extra DB call in Skin::lastModified().
1645          *
1646          * @param string|null $timestamp
1647          * @return mixed Previous value
1648          */
1649         public function setRevisionTimestamp( $timestamp ) {
1650                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1651         }
1652
1653         /**
1654          * Get the timestamp of displayed revision.
1655          * This will be null if not filled by setRevisionTimestamp().
1656          *
1657          * @return string|null
1658          */
1659         public function getRevisionTimestamp() {
1660                 return $this->mRevisionTimestamp;
1661         }
1662
1663         /**
1664          * Set the displayed file version
1665          *
1666          * @param File|bool $file
1667          * @return mixed Previous value
1668          */
1669         public function setFileVersion( $file ) {
1670                 $val = null;
1671                 if ( $file instanceof File && $file->exists() ) {
1672                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1673                 }
1674                 return wfSetVar( $this->mFileVersion, $val, true );
1675         }
1676
1677         /**
1678          * Get the displayed file version
1679          *
1680          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1681          */
1682         public function getFileVersion() {
1683                 return $this->mFileVersion;
1684         }
1685
1686         /**
1687          * Get the templates used on this page
1688          *
1689          * @return array (namespace => dbKey => revId)
1690          * @since 1.18
1691          */
1692         public function getTemplateIds() {
1693                 return $this->mTemplateIds;
1694         }
1695
1696         /**
1697          * Get the files used on this page
1698          *
1699          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1700          * @since 1.18
1701          */
1702         public function getFileSearchOptions() {
1703                 return $this->mImageTimeKeys;
1704         }
1705
1706         /**
1707          * Convert wikitext to HTML and add it to the buffer
1708          * Default assumes that the current page title will be used.
1709          *
1710          * @param string $text
1711          * @param bool $linestart Is this the start of a line?
1712          * @param bool $interface Is this text in the user interface language?
1713          * @throws MWException
1714          */
1715         public function addWikiText( $text, $linestart = true, $interface = true ) {
1716                 $title = $this->getTitle(); // Work around E_STRICT
1717                 if ( !$title ) {
1718                         throw new MWException( 'Title is null' );
1719                 }
1720                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1721         }
1722
1723         /**
1724          * Add wikitext with a custom Title object
1725          *
1726          * @param string $text Wikitext
1727          * @param Title &$title
1728          * @param bool $linestart Is this the start of a line?
1729          */
1730         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1731                 $this->addWikiTextTitle( $text, $title, $linestart );
1732         }
1733
1734         /**
1735          * Add wikitext with a custom Title object and tidy enabled.
1736          *
1737          * @param string $text Wikitext
1738          * @param Title &$title
1739          * @param bool $linestart Is this the start of a line?
1740          */
1741         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1742                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1743         }
1744
1745         /**
1746          * Add wikitext with tidy enabled
1747          *
1748          * @param string $text Wikitext
1749          * @param bool $linestart Is this the start of a line?
1750          */
1751         public function addWikiTextTidy( $text, $linestart = true ) {
1752                 $title = $this->getTitle();
1753                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1754         }
1755
1756         /**
1757          * Add wikitext with a custom Title object
1758          *
1759          * @param string $text Wikitext
1760          * @param Title $title
1761          * @param bool $linestart Is this the start of a line?
1762          * @param bool $tidy Whether to use tidy
1763          * @param bool $interface Whether it is an interface message
1764          *   (for example disables conversion)
1765          */
1766         public function addWikiTextTitle( $text, Title $title, $linestart,
1767                 $tidy = false, $interface = false
1768         ) {
1769                 global $wgParser;
1770
1771                 $popts = $this->parserOptions();
1772                 $oldTidy = $popts->setTidy( $tidy );
1773                 $popts->setInterfaceMessage( (bool)$interface );
1774
1775                 $parserOutput = $wgParser->getFreshParser()->parse(
1776                         $text, $title, $popts,
1777                         $linestart, true, $this->mRevisionId
1778                 );
1779
1780                 $popts->setTidy( $oldTidy );
1781
1782                 $this->addParserOutput( $parserOutput );
1783         }
1784
1785         /**
1786          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1787          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1788          * and so on.
1789          *
1790          * @since 1.24
1791          * @param ParserOutput $parserOutput
1792          */
1793         public function addParserOutputMetadata( $parserOutput ) {
1794                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1795                 $this->addCategoryLinks( $parserOutput->getCategories() );
1796                 $this->setIndicators( $parserOutput->getIndicators() );
1797                 $this->mNewSectionLink = $parserOutput->getNewSection();
1798                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1799
1800                 if ( !$parserOutput->isCacheable() ) {
1801                         $this->enableClientCache( false );
1802                 }
1803                 $this->mNoGallery = $parserOutput->getNoGallery();
1804                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1805                 $this->addModules( $parserOutput->getModules() );
1806                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1807                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1808                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1809                 $this->mPreventClickjacking = $this->mPreventClickjacking
1810                         || $parserOutput->preventClickjacking();
1811
1812                 // Template versioning...
1813                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1814                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1815                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1816                         } else {
1817                                 $this->mTemplateIds[$ns] = $dbks;
1818                         }
1819                 }
1820                 // File versioning...
1821                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1822                         $this->mImageTimeKeys[$dbk] = $data;
1823                 }
1824
1825                 // Hooks registered in the object
1826                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1827                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1828                         list( $hookName, $data ) = $hookInfo;
1829                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1830                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1831                         }
1832                 }
1833
1834                 // Enable OOUI if requested via ParserOutput
1835                 if ( $parserOutput->getEnableOOUI() ) {
1836                         $this->enableOOUI();
1837                 }
1838
1839                 // Include parser limit report
1840                 if ( !$this->limitReportJSData ) {
1841                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1842                 }
1843
1844                 // Link flags are ignored for now, but may in the future be
1845                 // used to mark individual language links.
1846                 $linkFlags = [];
1847                 // Avoid PHP 7.1 warning of passing $this by reference
1848                 $outputPage = $this;
1849                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1850                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1851
1852                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
1853                 // so that extensions may modify ParserOutput to toggle TOC.
1854                 // This cannot be moved to addParserOutputText because that is not
1855                 // called by EditPage for Preview.
1856                 if ( $parserOutput->getTOCEnabled() && $parserOutput->getTOCHTML() ) {
1857                         $this->mEnableTOC = true;
1858                 }
1859         }
1860
1861         /**
1862          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1863          * ParserOutput object, without any other metadata.
1864          *
1865          * @since 1.24
1866          * @param ParserOutput $parserOutput
1867          */
1868         public function addParserOutputContent( $parserOutput ) {
1869                 $this->addParserOutputText( $parserOutput );
1870
1871                 $this->addModules( $parserOutput->getModules() );
1872                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1873                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1874
1875                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1876         }
1877
1878         /**
1879          * Add the HTML associated with a ParserOutput object, without any metadata.
1880          *
1881          * @since 1.24
1882          * @param ParserOutput $parserOutput
1883          */
1884         public function addParserOutputText( $parserOutput ) {
1885                 $text = $parserOutput->getText();
1886                 // Avoid PHP 7.1 warning of passing $this by reference
1887                 $outputPage = $this;
1888                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1889                 $this->addHTML( $text );
1890         }
1891
1892         /**
1893          * Add everything from a ParserOutput object.
1894          *
1895          * @param ParserOutput $parserOutput
1896          */
1897         function addParserOutput( $parserOutput ) {
1898                 $this->addParserOutputMetadata( $parserOutput );
1899
1900                 // Touch section edit links only if not previously disabled
1901                 if ( $parserOutput->getEditSectionTokens() ) {
1902                         $parserOutput->setEditSectionTokens( $this->mEnableSectionEditLinks );
1903                 }
1904
1905                 $this->addParserOutputText( $parserOutput );
1906         }
1907
1908         /**
1909          * Add the output of a QuickTemplate to the output buffer
1910          *
1911          * @param QuickTemplate &$template
1912          */
1913         public function addTemplate( &$template ) {
1914                 $this->addHTML( $template->getHTML() );
1915         }
1916
1917         /**
1918          * Parse wikitext and return the HTML.
1919          *
1920          * @param string $text
1921          * @param bool $linestart Is this the start of a line?
1922          * @param bool $interface Use interface language ($wgLang instead of
1923          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1924          *   This also disables LanguageConverter.
1925          * @param Language $language Target language object, will override $interface
1926          * @throws MWException
1927          * @return string HTML
1928          */
1929         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1930                 global $wgParser;
1931
1932                 if ( is_null( $this->getTitle() ) ) {
1933                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1934                 }
1935
1936                 $popts = $this->parserOptions();
1937                 if ( $interface ) {
1938                         $popts->setInterfaceMessage( true );
1939                 }
1940                 if ( $language !== null ) {
1941                         $oldLang = $popts->setTargetLanguage( $language );
1942                 }
1943
1944                 $parserOutput = $wgParser->getFreshParser()->parse(
1945                         $text, $this->getTitle(), $popts,
1946                         $linestart, true, $this->mRevisionId
1947                 );
1948
1949                 if ( $interface ) {
1950                         $popts->setInterfaceMessage( false );
1951                 }
1952                 if ( $language !== null ) {
1953                         $popts->setTargetLanguage( $oldLang );
1954                 }
1955
1956                 return $parserOutput->getText();
1957         }
1958
1959         /**
1960          * Parse wikitext, strip paragraphs, and return the HTML.
1961          *
1962          * @param string $text
1963          * @param bool $linestart Is this the start of a line?
1964          * @param bool $interface Use interface language ($wgLang instead of
1965          *   $wgContLang) while parsing language sensitive magic
1966          *   words like GRAMMAR and PLURAL
1967          * @return string HTML
1968          */
1969         public function parseInline( $text, $linestart = true, $interface = false ) {
1970                 $parsed = $this->parse( $text, $linestart, $interface );
1971                 return Parser::stripOuterParagraph( $parsed );
1972         }
1973
1974         /**
1975          * @param int $maxage
1976          * @deprecated since 1.27 Use setCdnMaxage() instead
1977          */
1978         public function setSquidMaxage( $maxage ) {
1979                 $this->setCdnMaxage( $maxage );
1980         }
1981
1982         /**
1983          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1984          *
1985          * @param int $maxage Maximum cache time on the CDN, in seconds.
1986          */
1987         public function setCdnMaxage( $maxage ) {
1988                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1989         }
1990
1991         /**
1992          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1993          *
1994          * @param int $maxage Maximum cache time on the CDN, in seconds
1995          * @since 1.27
1996          */
1997         public function lowerCdnMaxage( $maxage ) {
1998                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1999                 $this->setCdnMaxage( $this->mCdnMaxage );
2000         }
2001
2002         /**
2003          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
2004          *
2005          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
2006          * the TTL is higher the older the $mtime timestamp is. Essentially, the
2007          * TTL is 90% of the age of the object, subject to the min and max.
2008          *
2009          * @param string|int|float|bool|null $mtime Last-Modified timestamp
2010          * @param int $minTTL Mimimum TTL in seconds [default: 1 minute]
2011          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
2012          * @return int TTL in seconds
2013          * @since 1.28
2014          */
2015         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
2016                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
2017                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
2018
2019                 if ( $mtime === null || $mtime === false ) {
2020                         return $minTTL; // entity does not exist
2021                 }
2022
2023                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
2024                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
2025                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
2026
2027                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2028
2029                 return $adaptiveTTL;
2030         }
2031
2032         /**
2033          * Use enableClientCache(false) to force it to send nocache headers
2034          *
2035          * @param bool $state
2036          *
2037          * @return bool
2038          */
2039         public function enableClientCache( $state ) {
2040                 return wfSetVar( $this->mEnableClientCache, $state );
2041         }
2042
2043         /**
2044          * Get the list of cookies that will influence on the cache
2045          *
2046          * @return array
2047          */
2048         function getCacheVaryCookies() {
2049                 static $cookies;
2050                 if ( $cookies === null ) {
2051                         $config = $this->getConfig();
2052                         $cookies = array_merge(
2053                                 SessionManager::singleton()->getVaryCookies(),
2054                                 [
2055                                         'forceHTTPS',
2056                                 ],
2057                                 $config->get( 'CacheVaryCookies' )
2058                         );
2059                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2060                 }
2061                 return $cookies;
2062         }
2063
2064         /**
2065          * Check if the request has a cache-varying cookie header
2066          * If it does, it's very important that we don't allow public caching
2067          *
2068          * @return bool
2069          */
2070         function haveCacheVaryCookies() {
2071                 $request = $this->getRequest();
2072                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2073                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2074                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2075                                 return true;
2076                         }
2077                 }
2078                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2079                 return false;
2080         }
2081
2082         /**
2083          * Add an HTTP header that will influence on the cache
2084          *
2085          * @param string $header Header name
2086          * @param string[]|null $option Options for the Key header. See
2087          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2088          * for the list of valid options.
2089          */
2090         public function addVaryHeader( $header, array $option = null ) {
2091                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2092                         $this->mVaryHeader[$header] = [];
2093                 }
2094                 if ( !is_array( $option ) ) {
2095                         $option = [];
2096                 }
2097                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2098         }
2099
2100         /**
2101          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2102          * such as Accept-Encoding or Cookie
2103          *
2104          * @return string
2105          */
2106         public function getVaryHeader() {
2107                 // If we vary on cookies, let's make sure it's always included here too.
2108                 if ( $this->getCacheVaryCookies() ) {
2109                         $this->addVaryHeader( 'Cookie' );
2110                 }
2111
2112                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2113                         $this->addVaryHeader( $header, $options );
2114                 }
2115                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2116         }
2117
2118         /**
2119          * Add an HTTP Link: header
2120          *
2121          * @param string $header Header value
2122          */
2123         public function addLinkHeader( $header ) {
2124                 $this->mLinkHeader[] = $header;
2125         }
2126
2127         /**
2128          * Return a Link: header. Based on the values of $mLinkHeader.
2129          *
2130          * @return string
2131          */
2132         public function getLinkHeader() {
2133                 if ( !$this->mLinkHeader ) {
2134                         return false;
2135                 }
2136
2137                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2138         }
2139
2140         /**
2141          * Get a complete Key header
2142          *
2143          * @return string
2144          */
2145         public function getKeyHeader() {
2146                 $cvCookies = $this->getCacheVaryCookies();
2147
2148                 $cookiesOption = [];
2149                 foreach ( $cvCookies as $cookieName ) {
2150                         $cookiesOption[] = 'param=' . $cookieName;
2151                 }
2152                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2153
2154                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2155                         $this->addVaryHeader( $header, $options );
2156                 }
2157
2158                 $headers = [];
2159                 foreach ( $this->mVaryHeader as $header => $option ) {
2160                         $newheader = $header;
2161                         if ( is_array( $option ) && count( $option ) > 0 ) {
2162                                 $newheader .= ';' . implode( ';', $option );
2163                         }
2164                         $headers[] = $newheader;
2165                 }
2166                 $key = 'Key: ' . implode( ',', $headers );
2167
2168                 return $key;
2169         }
2170
2171         /**
2172          * T23672: Add Accept-Language to Vary and Key headers
2173          * if there's no 'variant' parameter existed in GET.
2174          *
2175          * For example:
2176          *   /w/index.php?title=Main_page should always be served; but
2177          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2178          */
2179         function addAcceptLanguage() {
2180                 $title = $this->getTitle();
2181                 if ( !$title instanceof Title ) {
2182                         return;
2183                 }
2184
2185                 $lang = $title->getPageLanguage();
2186                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2187                         $variants = $lang->getVariants();
2188                         $aloption = [];
2189                         foreach ( $variants as $variant ) {
2190                                 if ( $variant === $lang->getCode() ) {
2191                                         continue;
2192                                 } else {
2193                                         $aloption[] = 'substr=' . $variant;
2194
2195                                         // IE and some other browsers use BCP 47 standards in
2196                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2197                                         // We should handle these too.
2198                                         $variantBCP47 = LanguageCode::bcp47( $variant );
2199                                         if ( $variantBCP47 !== $variant ) {
2200                                                 $aloption[] = 'substr=' . $variantBCP47;
2201                                         }
2202                                 }
2203                         }
2204                         $this->addVaryHeader( 'Accept-Language', $aloption );
2205                 }
2206         }
2207
2208         /**
2209          * Set a flag which will cause an X-Frame-Options header appropriate for
2210          * edit pages to be sent. The header value is controlled by
2211          * $wgEditPageFrameOptions.
2212          *
2213          * This is the default for special pages. If you display a CSRF-protected
2214          * form on an ordinary view page, then you need to call this function.
2215          *
2216          * @param bool $enable
2217          */
2218         public function preventClickjacking( $enable = true ) {
2219                 $this->mPreventClickjacking = $enable;
2220         }
2221
2222         /**
2223          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2224          * This can be called from pages which do not contain any CSRF-protected
2225          * HTML form.
2226          */
2227         public function allowClickjacking() {
2228                 $this->mPreventClickjacking = false;
2229         }
2230
2231         /**
2232          * Get the prevent-clickjacking flag
2233          *
2234          * @since 1.24
2235          * @return bool
2236          */
2237         public function getPreventClickjacking() {
2238                 return $this->mPreventClickjacking;
2239         }
2240
2241         /**
2242          * Get the X-Frame-Options header value (without the name part), or false
2243          * if there isn't one. This is used by Skin to determine whether to enable
2244          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2245          *
2246          * @return string|false
2247          */
2248         public function getFrameOptions() {
2249                 $config = $this->getConfig();
2250                 if ( $config->get( 'BreakFrames' ) ) {
2251                         return 'DENY';
2252                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2253                         return $config->get( 'EditPageFrameOptions' );
2254                 }
2255                 return false;
2256         }
2257
2258         /**
2259          * Send cache control HTTP headers
2260          */
2261         public function sendCacheControl() {
2262                 $response = $this->getRequest()->response();
2263                 $config = $this->getConfig();
2264
2265                 $this->addVaryHeader( 'Cookie' );
2266                 $this->addAcceptLanguage();
2267
2268                 # don't serve compressed data to clients who can't handle it
2269                 # maintain different caches for logged-in users and non-logged in ones
2270                 $response->header( $this->getVaryHeader() );
2271
2272                 if ( $config->get( 'UseKeyHeader' ) ) {
2273                         $response->header( $this->getKeyHeader() );
2274                 }
2275
2276                 if ( $this->mEnableClientCache ) {
2277                         if (
2278                                 $config->get( 'UseSquid' ) &&
2279                                 !$response->hasCookies() &&
2280                                 !SessionManager::getGlobalSession()->isPersistent() &&
2281                                 !$this->isPrintable() &&
2282                                 $this->mCdnMaxage != 0 &&
2283                                 !$this->haveCacheVaryCookies()
2284                         ) {
2285                                 if ( $config->get( 'UseESI' ) ) {
2286                                         # We'll purge the proxy cache explicitly, but require end user agents
2287                                         # to revalidate against the proxy on each visit.
2288                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2289                                         wfDebug( __METHOD__ .
2290                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2291                                         # start with a shorter timeout for initial testing
2292                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2293                                         $response->header(
2294                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2295                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2296                                         );
2297                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2298                                 } else {
2299                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2300                                         # to revalidate against the proxy on each visit.
2301                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2302                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2303                                         wfDebug( __METHOD__ .
2304                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2305                                         # start with a shorter timeout for initial testing
2306                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2307                                         $response->header( "Cache-Control: " .
2308                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2309                                 }
2310                         } else {
2311                                 # We do want clients to cache if they can, but they *must* check for updates
2312                                 # on revisiting the page.
2313                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2314                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2315                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2316                         }
2317                         if ( $this->mLastModified ) {
2318                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2319                         }
2320                 } else {
2321                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2322
2323                         # In general, the absence of a last modified header should be enough to prevent
2324                         # the client from using its cache. We send a few other things just to make sure.
2325                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2326                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2327                         $response->header( 'Pragma: no-cache' );
2328                 }
2329         }
2330
2331         /**
2332          * Finally, all the text has been munged and accumulated into
2333          * the object, let's actually output it:
2334          *
2335          * @param bool $return Set to true to get the result as a string rather than sending it
2336          * @return string|null
2337          * @throws Exception
2338          * @throws FatalError
2339          * @throws MWException
2340          */
2341         public function output( $return = false ) {
2342                 global $wgContLang;
2343
2344                 if ( $this->mDoNothing ) {
2345                         return $return ? '' : null;
2346                 }
2347
2348                 $response = $this->getRequest()->response();
2349                 $config = $this->getConfig();
2350
2351                 if ( $this->mRedirect != '' ) {
2352                         # Standards require redirect URLs to be absolute
2353                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2354
2355                         $redirect = $this->mRedirect;
2356                         $code = $this->mRedirectCode;
2357
2358                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2359                                 if ( $code == '301' || $code == '303' ) {
2360                                         if ( !$config->get( 'DebugRedirects' ) ) {
2361                                                 $response->statusHeader( $code );
2362                                         }
2363                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2364                                 }
2365                                 if ( $config->get( 'VaryOnXFP' ) ) {
2366                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2367                                 }
2368                                 $this->sendCacheControl();
2369
2370                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2371                                 if ( $config->get( 'DebugRedirects' ) ) {
2372                                         $url = htmlspecialchars( $redirect );
2373                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2374                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2375                                         print "</body>\n</html>\n";
2376                                 } else {
2377                                         $response->header( 'Location: ' . $redirect );
2378                                 }
2379                         }
2380
2381                         return $return ? '' : null;
2382                 } elseif ( $this->mStatusCode ) {
2383                         $response->statusHeader( $this->mStatusCode );
2384                 }
2385
2386                 # Buffer output; final headers may depend on later processing
2387                 ob_start();
2388
2389                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2390                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2391
2392                 // Avoid Internet Explorer "compatibility view" in IE 8-10, so that
2393                 // jQuery etc. can work correctly.
2394                 $response->header( 'X-UA-Compatible: IE=Edge' );
2395
2396                 if ( !$this->mArticleBodyOnly ) {
2397                         $sk = $this->getSkin();
2398
2399                         if ( $sk->shouldPreloadLogo() ) {
2400                                 $this->addLogoPreloadLinkHeaders();
2401                         }
2402                 }
2403
2404                 $linkHeader = $this->getLinkHeader();
2405                 if ( $linkHeader ) {
2406                         $response->header( $linkHeader );
2407                 }
2408
2409                 // Prevent framing, if requested
2410                 $frameOptions = $this->getFrameOptions();
2411                 if ( $frameOptions ) {
2412                         $response->header( "X-Frame-Options: $frameOptions" );
2413                 }
2414
2415                 if ( $this->mArticleBodyOnly ) {
2416                         echo $this->mBodytext;
2417                 } else {
2418                         // Enable safe mode if requested
2419                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2420                                 $this->disallowUserJs();
2421                         }
2422
2423                         $sk = $this->getSkin();
2424                         foreach ( $sk->getDefaultModules() as $group ) {
2425                                 $this->addModules( $group );
2426                         }
2427
2428                         MWDebug::addModules( $this );
2429
2430                         // Avoid PHP 7.1 warning of passing $this by reference
2431                         $outputPage = $this;
2432                         // Hook that allows last minute changes to the output page, e.g.
2433                         // adding of CSS or Javascript by extensions.
2434                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$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::runWithoutAbort( '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
2921                 // Use an IE conditional comment to serve the script only to old IE
2922                 $pieces[] = '<!--[if lt IE 9]>' .
2923                         ResourceLoaderClientHtml::makeLoad(
2924                                 ResourceLoaderContext::newDummyContext(),
2925                                 [ 'html5shiv' ],
2926                                 ResourceLoaderModule::TYPE_SCRIPTS,
2927                                 [ 'sync' => true ]
2928                         ) .
2929                         '<![endif]-->';
2930
2931                 $pieces[] = Html::closeElement( 'head' );
2932
2933                 $bodyClasses = $this->mAdditionalBodyClasses;
2934                 $bodyClasses[] = 'mediawiki';
2935
2936                 # Classes for LTR/RTL directionality support
2937                 $bodyClasses[] = $userdir;
2938                 $bodyClasses[] = "sitedir-$sitedir";
2939
2940                 $underline = $this->getUser()->getOption( 'underline' );
2941                 if ( $underline < 2 ) {
2942                         // The following classes can be used here:
2943                         // * mw-underline-always
2944                         // * mw-underline-never
2945                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2946                 }
2947
2948                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2949                         # A <body> class is probably not the best way to do this . . .
2950                         $bodyClasses[] = 'capitalize-all-nouns';
2951                 }
2952
2953                 // Parser feature migration class
2954                 // The idea is that this will eventually be removed, after the wikitext
2955                 // which requires it is cleaned up.
2956                 $bodyClasses[] = 'mw-hide-empty-elt';
2957
2958                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2959                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2960                 $bodyClasses[] =
2961                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2962
2963                 $bodyAttrs = [];
2964                 // While the implode() is not strictly needed, it's used for backwards compatibility
2965                 // (this used to be built as a string and hooks likely still expect that).
2966                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2967
2968                 // Allow skins and extensions to add body attributes they need
2969                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2970                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2971
2972                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2973
2974                 return self::combineWrappedStrings( $pieces );
2975         }
2976
2977         /**
2978          * Get a ResourceLoader object associated with this OutputPage
2979          *
2980          * @return ResourceLoader
2981          */
2982         public function getResourceLoader() {
2983                 if ( is_null( $this->mResourceLoader ) ) {
2984                         $this->mResourceLoader = new ResourceLoader(
2985                                 $this->getConfig(),
2986                                 LoggerFactory::getInstance( 'resourceloader' )
2987                         );
2988                 }
2989                 return $this->mResourceLoader;
2990         }
2991
2992         /**
2993          * Explicily load or embed modules on a page.
2994          *
2995          * @param array|string $modules One or more module names
2996          * @param string $only ResourceLoaderModule TYPE_ class constant
2997          * @param array $extraQuery [optional] Array with extra query parameters for the request
2998          * @return string|WrappedStringList HTML
2999          */
3000         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
3001                 // Apply 'target' and 'origin' filters
3002                 $modules = $this->filterModules( (array)$modules, null, $only );
3003
3004                 return ResourceLoaderClientHtml::makeLoad(
3005                         $this->getRlClientContext(),
3006                         $modules,
3007                         $only,
3008                         $extraQuery
3009                 );
3010         }
3011
3012         /**
3013          * Combine WrappedString chunks and filter out empty ones
3014          *
3015          * @param array $chunks
3016          * @return string|WrappedStringList HTML
3017          */
3018         protected static function combineWrappedStrings( array $chunks ) {
3019                 // Filter out empty values
3020                 $chunks = array_filter( $chunks, 'strlen' );
3021                 return WrappedString::join( "\n", $chunks );
3022         }
3023
3024         private function isUserJsPreview() {
3025                 return $this->getConfig()->get( 'AllowUserJs' )
3026                         && $this->getTitle()
3027                         && $this->getTitle()->isJsSubpage()
3028                         && $this->userCanPreview();
3029         }
3030
3031         protected function isUserCssPreview() {
3032                 return $this->getConfig()->get( 'AllowUserCss' )
3033                         && $this->getTitle()
3034                         && $this->getTitle()->isCssSubpage()
3035                         && $this->userCanPreview();
3036         }
3037
3038         /**
3039          * JS stuff to put at the bottom of the `<body>`. These are modules with position 'bottom',
3040          * legacy scripts ($this->mScripts), and user JS.
3041          *
3042          * @return string|WrappedStringList HTML
3043          */
3044         public function getBottomScripts() {
3045                 $chunks = [];
3046                 $chunks[] = $this->getRlClient()->getBodyHtml();
3047
3048                 // Legacy non-ResourceLoader scripts
3049                 $chunks[] = $this->mScripts;
3050
3051                 // Exempt 'user' module
3052                 // - May need excludepages for live preview. (T28283)
3053                 // - Must use TYPE_COMBINED so its response is handled by mw.loader.implement() which
3054                 //   ensures execution is scheduled after the "site" module.
3055                 // - Don't load if module state is already resolved as "ready".
3056                 if ( $this->rlUserModuleState === 'loading' ) {
3057                         if ( $this->isUserJsPreview() ) {
3058                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED,
3059                                         [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3060                                 );
3061                                 $chunks[] = ResourceLoader::makeInlineScript(
3062                                         Xml::encodeJsCall( 'mw.loader.using', [
3063                                                 [ 'user', 'site' ],
3064                                                 new XmlJsCode(
3065                                                         'function () {'
3066                                                                 . Xml::encodeJsCall( '$.globalEval', [
3067                                                                         $this->getRequest()->getText( 'wpTextbox1' )
3068                                                                 ] )
3069                                                                 . '}'
3070                                                 )
3071                                         ] )
3072                                 );
3073                                 // FIXME: If the user is previewing, say, ./vector.js, his ./common.js will be loaded
3074                                 // asynchronously and may arrive *after* the inline script here. So the previewed code
3075                                 // may execute before ./common.js runs. Normally, ./common.js runs before ./vector.js.
3076                                 // Similarly, when previewing ./common.js and the user module does arrive first,
3077                                 // it will arrive without common.js and the inline script runs after.
3078                                 // Thus running common after the excluded subpage.
3079                         } else {
3080                                 // Load normally
3081                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED );
3082                         }
3083                 }
3084
3085                 if ( $this->limitReportJSData ) {
3086                         $chunks[] = ResourceLoader::makeInlineScript(
3087                                 ResourceLoader::makeConfigSetScript(
3088                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3089                                 )
3090                         );
3091                 }
3092
3093                 return self::combineWrappedStrings( $chunks );
3094         }
3095
3096         /**
3097          * Get the javascript config vars to include on this page
3098          *
3099          * @return array Array of javascript config vars
3100          * @since 1.23
3101          */
3102         public function getJsConfigVars() {
3103                 return $this->mJsConfigVars;
3104         }
3105
3106         /**
3107          * Add one or more variables to be set in mw.config in JavaScript
3108          *
3109          * @param string|array $keys Key or array of key/value pairs
3110          * @param mixed $value [optional] Value of the configuration variable
3111          */
3112         public function addJsConfigVars( $keys, $value = null ) {
3113                 if ( is_array( $keys ) ) {
3114                         foreach ( $keys as $key => $value ) {
3115                                 $this->mJsConfigVars[$key] = $value;
3116                         }
3117                         return;
3118                 }
3119
3120                 $this->mJsConfigVars[$keys] = $value;
3121         }
3122
3123         /**
3124          * Get an array containing the variables to be set in mw.config in JavaScript.
3125          *
3126          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3127          * - in other words, page-independent/site-wide variables (without state).
3128          * You will only be adding bloat to the html page and causing page caches to
3129          * have to be purged on configuration changes.
3130          * @return array
3131          */
3132         public function getJSVars() {
3133                 global $wgContLang;
3134
3135                 $curRevisionId = 0;
3136                 $articleId = 0;
3137                 $canonicalSpecialPageName = false; # T23115
3138
3139                 $title = $this->getTitle();
3140                 $ns = $title->getNamespace();
3141                 $canonicalNamespace = MWNamespace::exists( $ns )
3142                         ? MWNamespace::getCanonicalName( $ns )
3143                         : $title->getNsText();
3144
3145                 $sk = $this->getSkin();
3146                 // Get the relevant title so that AJAX features can use the correct page name
3147                 // when making API requests from certain special pages (T36972).
3148                 $relevantTitle = $sk->getRelevantTitle();
3149                 $relevantUser = $sk->getRelevantUser();
3150
3151                 if ( $ns == NS_SPECIAL ) {
3152                         list( $canonicalSpecialPageName, /*...*/ ) =
3153                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3154                 } elseif ( $this->canUseWikiPage() ) {
3155                         $wikiPage = $this->getWikiPage();
3156                         $curRevisionId = $wikiPage->getLatest();
3157                         $articleId = $wikiPage->getId();
3158                 }
3159
3160                 $lang = $title->getPageViewLanguage();
3161
3162                 // Pre-process information
3163                 $separatorTransTable = $lang->separatorTransformTable();
3164                 $separatorTransTable = $separatorTransTable ? $separatorTransTable : [];
3165                 $compactSeparatorTransTable = [
3166                         implode( "\t", array_keys( $separatorTransTable ) ),
3167                         implode( "\t", $separatorTransTable ),
3168                 ];
3169                 $digitTransTable = $lang->digitTransformTable();
3170                 $digitTransTable = $digitTransTable ? $digitTransTable : [];
3171                 $compactDigitTransTable = [
3172                         implode( "\t", array_keys( $digitTransTable ) ),
3173                         implode( "\t", $digitTransTable ),
3174                 ];
3175
3176                 $user = $this->getUser();
3177
3178                 $vars = [
3179                         'wgCanonicalNamespace' => $canonicalNamespace,
3180                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3181                         'wgNamespaceNumber' => $title->getNamespace(),
3182                         'wgPageName' => $title->getPrefixedDBkey(),
3183                         'wgTitle' => $title->getText(),
3184                         'wgCurRevisionId' => $curRevisionId,
3185                         'wgRevisionId' => (int)$this->getRevisionId(),
3186                         'wgArticleId' => $articleId,
3187                         'wgIsArticle' => $this->isArticle(),
3188                         'wgIsRedirect' => $title->isRedirect(),
3189                         'wgAction' => Action::getActionName( $this->getContext() ),
3190                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3191                         'wgUserGroups' => $user->getEffectiveGroups(),
3192                         'wgCategories' => $this->getCategories(),
3193                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3194                         'wgPageContentLanguage' => $lang->getCode(),
3195                         'wgPageContentModel' => $title->getContentModel(),
3196                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3197                         'wgDigitTransformTable' => $compactDigitTransTable,
3198                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3199                         'wgMonthNames' => $lang->getMonthNamesArray(),
3200                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3201                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3202                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3203                         'wgRequestId' => WebRequest::getRequestId(),
3204                 ];
3205
3206                 if ( $user->isLoggedIn() ) {
3207                         $vars['wgUserId'] = $user->getId();
3208                         $vars['wgUserEditCount'] = $user->getEditCount();
3209                         $userReg = $user->getRegistration();
3210                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3211                         // Get the revision ID of the oldest new message on the user's talk
3212                         // page. This can be used for constructing new message alerts on
3213                         // the client side.
3214                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3215                 }
3216
3217                 if ( $wgContLang->hasVariants() ) {
3218                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3219                 }
3220                 // Same test as SkinTemplate
3221                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3222                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3223
3224                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3225                         && $relevantTitle->quickUserCan( 'edit', $user )
3226                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3227
3228                 foreach ( $title->getRestrictionTypes() as $type ) {
3229                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3230                 }
3231
3232                 if ( $title->isMainPage() ) {
3233                         $vars['wgIsMainPage'] = true;
3234                 }
3235
3236                 if ( $this->mRedirectedFrom ) {
3237                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3238                 }
3239
3240                 if ( $relevantUser ) {
3241                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3242                 }
3243
3244                 // Allow extensions to add their custom variables to the mw.config map.
3245                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3246                 // page-dependant but site-wide (without state).
3247                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3248                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3249
3250                 // Merge in variables from addJsConfigVars last
3251                 return array_merge( $vars, $this->getJsConfigVars() );
3252         }
3253
3254         /**
3255          * To make it harder for someone to slip a user a fake
3256          * user-JavaScript or user-CSS preview, a random token
3257          * is associated with the login session. If it's not
3258          * passed back with the preview request, we won't render
3259          * the code.
3260          *
3261          * @return bool
3262          */
3263         public function userCanPreview() {
3264                 $request = $this->getRequest();
3265                 if (
3266                         $request->getVal( 'action' ) !== 'submit' ||
3267                         !$request->getCheck( 'wpPreview' ) ||
3268                         !$request->wasPosted()
3269                 ) {
3270                         return false;
3271                 }
3272
3273                 $user = $this->getUser();
3274
3275                 if ( !$user->isLoggedIn() ) {
3276                         // Anons have predictable edit tokens
3277                         return false;
3278                 }
3279                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3280                         return false;
3281                 }
3282
3283                 $title = $this->getTitle();
3284                 if ( !$title->isJsSubpage() && !$title->isCssSubpage() ) {
3285                         return false;
3286                 }
3287                 if ( !$title->isSubpageOf( $user->getUserPage() ) ) {
3288                         // Don't execute another user's CSS or JS on preview (T85855)
3289                         return false;
3290                 }
3291
3292                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3293                 if ( count( $errors ) !== 0 ) {
3294                         return false;
3295                 }
3296
3297                 return true;
3298         }
3299
3300         /**
3301          * @return array Array in format "link name or number => 'link html'".
3302          */
3303         public function getHeadLinksArray() {
3304                 global $wgVersion;
3305
3306                 $tags = [];
3307                 $config = $this->getConfig();
3308
3309                 $canonicalUrl = $this->mCanonicalUrl;
3310
3311                 $tags['meta-generator'] = Html::element( 'meta', [
3312                         'name' => 'generator',
3313                         'content' => "MediaWiki $wgVersion",
3314                 ] );
3315
3316                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3317                         $tags['meta-referrer'] = Html::element( 'meta', [
3318                                 'name' => 'referrer',
3319                                 'content' => $config->get( 'ReferrerPolicy' )
3320                         ] );
3321                 }
3322
3323                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3324                 if ( $p !== 'index,follow' ) {
3325                         // http://www.robotstxt.org/wc/meta-user.html
3326                         // Only show if it's different from the default robots policy
3327                         $tags['meta-robots'] = Html::element( 'meta', [
3328                                 'name' => 'robots',
3329                                 'content' => $p,
3330                         ] );
3331                 }
3332
3333                 foreach ( $this->mMetatags as $tag ) {
3334                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3335                                 $a = 'http-equiv';
3336                                 $tag[0] = substr( $tag[0], 5 );
3337                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3338                                 $a = 'property';
3339                         } else {
3340                                 $a = 'name';
3341                         }
3342                         $tagName = "meta-{$tag[0]}";
3343                         if ( isset( $tags[$tagName] ) ) {
3344                                 $tagName .= $tag[1];
3345                         }
3346                         $tags[$tagName] = Html::element( 'meta',
3347                                 [
3348                                         $a => $tag[0],
3349                                         'content' => $tag[1]
3350                                 ]
3351                         );
3352                 }
3353
3354                 foreach ( $this->mLinktags as $tag ) {
3355                         $tags[] = Html::element( 'link', $tag );
3356                 }
3357
3358                 # Universal edit button
3359                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3360                         $user = $this->getUser();
3361                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3362                                 && ( $this->getTitle()->exists() ||
3363                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3364                         ) {
3365                                 // Original UniversalEditButton
3366                                 $msg = $this->msg( 'edit' )->text();
3367                                 $tags['universal-edit-button'] = Html::element( 'link', [
3368                                         'rel' => 'alternate',
3369                                         'type' => 'application/x-wiki',
3370                                         'title' => $msg,
3371                                         'href' => $this->getTitle()->getEditURL(),
3372                                 ] );
3373                                 // Alternate edit link
3374                                 $tags['alternative-edit'] = Html::element( 'link', [
3375                                         'rel' => 'edit',
3376                                         'title' => $msg,
3377                                         'href' => $this->getTitle()->getEditURL(),
3378                                 ] );
3379                         }
3380                 }
3381
3382                 # Generally the order of the favicon and apple-touch-icon links
3383                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3384                 # uses whichever one appears later in the HTML source. Make sure
3385                 # apple-touch-icon is specified first to avoid this.
3386                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3387                         $tags['apple-touch-icon'] = Html::element( 'link', [
3388                                 'rel' => 'apple-touch-icon',
3389                                 'href' => $config->get( 'AppleTouchIcon' )
3390                         ] );
3391                 }
3392
3393                 if ( $config->get( 'Favicon' ) !== false ) {
3394                         $tags['favicon'] = Html::element( 'link', [
3395                                 'rel' => 'shortcut icon',
3396                                 'href' => $config->get( 'Favicon' )
3397                         ] );
3398                 }
3399
3400                 # OpenSearch description link
3401                 $tags['opensearch'] = Html::element( 'link', [
3402                         'rel' => 'search',
3403                         'type' => 'application/opensearchdescription+xml',
3404                         'href' => wfScript( 'opensearch_desc' ),
3405                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3406                 ] );
3407
3408                 if ( $config->get( 'EnableAPI' ) ) {
3409                         # Real Simple Discovery link, provides auto-discovery information
3410                         # for the MediaWiki API (and potentially additional custom API
3411                         # support such as WordPress or Twitter-compatible APIs for a
3412                         # blogging extension, etc)
3413                         $tags['rsd'] = Html::element( 'link', [
3414                                 'rel' => 'EditURI',
3415                                 'type' => 'application/rsd+xml',
3416                                 // Output a protocol-relative URL here if $wgServer is protocol-relative.
3417                                 // Whether RSD accepts relative or protocol-relative URLs is completely
3418                                 // undocumented, though.
3419                                 'href' => wfExpandUrl( wfAppendQuery(
3420                                         wfScript( 'api' ),
3421                                         [ 'action' => 'rsd' ] ),
3422                                         PROTO_RELATIVE
3423                                 ),
3424                         ] );
3425                 }
3426
3427                 # Language variants
3428                 if ( !$config->get( 'DisableLangConversion' ) ) {
3429                         $lang = $this->getTitle()->getPageLanguage();
3430                         if ( $lang->hasVariants() ) {
3431                                 $variants = $lang->getVariants();
3432                                 foreach ( $variants as $variant ) {
3433                                         $tags["variant-$variant"] = Html::element( 'link', [
3434                                                 'rel' => 'alternate',
3435                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3436                                                 'href' => $this->getTitle()->getLocalURL(
3437                                                         [ 'variant' => $variant ] )
3438                                                 ]
3439                                         );
3440                                 }
3441                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3442                                 $tags["variant-x-default"] = Html::element( 'link', [
3443                                         'rel' => 'alternate',
3444                                         'hreflang' => 'x-default',
3445                                         'href' => $this->getTitle()->getLocalURL() ] );
3446                         }
3447                 }
3448
3449                 # Copyright
3450                 if ( $this->copyrightUrl !== null ) {
3451                         $copyright = $this->copyrightUrl;
3452                 } else {
3453                         $copyright = '';
3454                         if ( $config->get( 'RightsPage' ) ) {
3455                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3456
3457                                 if ( $copy ) {
3458                                         $copyright = $copy->getLocalURL();
3459                                 }
3460                         }
3461
3462                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3463                                 $copyright = $config->get( 'RightsUrl' );
3464                         }
3465                 }
3466
3467                 if ( $copyright ) {
3468                         $tags['copyright'] = Html::element( 'link', [
3469                                 'rel' => 'license',
3470                                 'href' => $copyright ]
3471                         );
3472                 }
3473
3474                 # Feeds
3475                 if ( $config->get( 'Feed' ) ) {
3476                         $feedLinks = [];
3477
3478                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3479                                 # Use the page name for the title.  In principle, this could
3480                                 # lead to issues with having the same name for different feeds
3481                                 # corresponding to the same page, but we can't avoid that at
3482                                 # this low a level.
3483
3484                                 $feedLinks[] = $this->feedLink(
3485                                         $format,
3486                                         $link,
3487                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3488                                         $this->msg(
3489                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3490                                         )->text()
3491                                 );
3492                         }
3493
3494                         # Recent changes feed should appear on every page (except recentchanges,
3495                         # that would be redundant). Put it after the per-page feed to avoid
3496                         # changing existing behavior. It's still available, probably via a
3497                         # menu in your browser. Some sites might have a different feed they'd
3498                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3499                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3500                         # If so, use it instead.
3501                         $sitename = $config->get( 'Sitename' );
3502                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3503                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3504                                         // Note, this->feedLink escapes the url.
3505                                         $feedLinks[] = $this->feedLink(
3506                                                 $type,
3507                                                 $feedUrl,
3508                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3509                                         );
3510                                 }
3511                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3512                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3513                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3514                                         $feedLinks[] = $this->feedLink(
3515                                                 $format,
3516                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3517                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3518                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3519                                         );
3520                                 }
3521                         }
3522
3523                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3524                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3525                         # use OutputPage::addFeedLink() instead.
3526                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3527
3528                         $tags += $feedLinks;
3529                 }
3530
3531                 # Canonical URL
3532                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3533                         if ( $canonicalUrl !== false ) {
3534                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3535                         } else {
3536                                 if ( $this->isArticleRelated() ) {
3537                                         // This affects all requests where "setArticleRelated" is true. This is
3538                                         // typically all requests that show content (query title, curid, oldid, diff),
3539                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3540                                         // It does not apply to File pages and Special pages.
3541                                         // 'history' and 'info' actions address page metadata rather than the page
3542                                         // content itself, so they may not be canonicalized to the view page url.
3543                                         // TODO: this ought to be better encapsulated in the Action class.
3544                                         $action = Action::getActionName( $this->getContext() );
3545                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3546                                                 $query = "action={$action}";
3547                                         } else {
3548                                                 $query = '';
3549                                         }
3550                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3551                                 } else {
3552                                         $reqUrl = $this->getRequest()->getRequestURL();
3553                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3554                                 }
3555                         }
3556                 }
3557                 if ( $canonicalUrl !== false ) {
3558                         $tags[] = Html::element( 'link', [
3559                                 'rel' => 'canonical',
3560                                 'href' => $canonicalUrl
3561                         ] );
3562                 }
3563
3564                 return $tags;
3565         }
3566
3567         /**
3568          * Generate a "<link rel/>" for a feed.
3569          *
3570          * @param string $type Feed type
3571          * @param string $url URL to the feed
3572          * @param string $text Value of the "title" attribute
3573          * @return string HTML fragment
3574          */
3575         private function feedLink( $type, $url, $text ) {
3576                 return Html::element( 'link', [
3577                         'rel' => 'alternate',
3578                         'type' => "application/$type+xml",
3579                         'title' => $text,
3580                         'href' => $url ]
3581                 );
3582         }
3583
3584         /**
3585          * Add a local or specified stylesheet, with the given media options.
3586          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3587          *
3588          * @param string $style URL to the file
3589          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3590          * @param string $condition For IE conditional comments, specifying an IE version
3591          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3592          */
3593         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3594                 $options = [];
3595                 if ( $media ) {
3596                         $options['media'] = $media;
3597                 }
3598                 if ( $condition ) {
3599                         $options['condition'] = $condition;
3600                 }
3601                 if ( $dir ) {
3602                         $options['dir'] = $dir;
3603                 }
3604                 $this->styles[$style] = $options;
3605         }
3606
3607         /**
3608          * Adds inline CSS styles
3609          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3610          *
3611          * @param mixed $style_css Inline CSS
3612          * @param string $flip Set to 'flip' to flip the CSS if needed
3613          */
3614         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3615                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3616                         # If wanted, and the interface is right-to-left, flip the CSS
3617                         $style_css = CSSJanus::transform( $style_css, true, false );
3618                 }
3619                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3620         }
3621
3622         /**
3623          * Build exempt modules and legacy non-ResourceLoader styles.
3624          *
3625          * @return string|WrappedStringList HTML
3626          */
3627         protected function buildExemptModules() {
3628                 global $wgContLang;
3629
3630                 $chunks = [];
3631                 // Things that go after the ResourceLoaderDynamicStyles marker
3632                 $append = [];
3633
3634                 // Exempt 'user' styles module (may need 'excludepages' for live preview)
3635                 if ( $this->isUserCssPreview() ) {
3636                         $append[] = $this->makeResourceLoaderLink(
3637                                 'user.styles',
3638                                 ResourceLoaderModule::TYPE_STYLES,
3639                                 [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3640                         );
3641
3642                         // Load the previewed CSS. Janus it if needed.
3643                         // User-supplied CSS is assumed to in the wiki's content language.
3644                         $previewedCSS = $this->getRequest()->getText( 'wpTextbox1' );
3645                         if ( $this->getLanguage()->getDir() !== $wgContLang->getDir() ) {
3646                                 $previewedCSS = CSSJanus::transform( $previewedCSS, true, false );
3647                         }
3648                         $append[] = Html::inlineStyle( $previewedCSS );
3649                 }
3650
3651                 // We want site, private and user styles to override dynamically added styles from
3652                 // general modules, but we want dynamically added styles to override statically added
3653                 // style modules. So the order has to be:
3654                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3655                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3656                 // - ResourceLoaderDynamicStyles marker
3657                 // - site/private/user styles
3658
3659                 // Add legacy styles added through addStyle()/addInlineStyle() here
3660                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3661
3662                 $chunks[] = Html::element(
3663                         'meta',
3664                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3665                 );
3666
3667                 $separateReq = [ 'site.styles', 'user.styles' ];
3668                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3669                         // Combinable modules
3670                         $chunks[] = $this->makeResourceLoaderLink(
3671                                 array_diff( $moduleNames, $separateReq ),
3672                                 ResourceLoaderModule::TYPE_STYLES
3673                         );
3674
3675                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3676                                 // These require their own dedicated request in order to support "@import"
3677                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3678                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3679                                         ResourceLoaderModule::TYPE_STYLES
3680                                 );
3681                         }
3682                 }
3683
3684                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3685         }
3686
3687         /**
3688          * @return array
3689          */
3690         public function buildCssLinksArray() {
3691                 $links = [];
3692
3693                 // Add any extension CSS
3694                 foreach ( $this->mExtStyles as $url ) {
3695                         $this->addStyle( $url );
3696                 }
3697                 $this->mExtStyles = [];
3698
3699                 foreach ( $this->styles as $file => $options ) {
3700                         $link = $this->styleLink( $file, $options );
3701                         if ( $link ) {
3702                                 $links[$file] = $link;
3703                         }
3704                 }
3705                 return $links;
3706         }
3707
3708         /**
3709          * Generate \<link\> tags for stylesheets
3710          *
3711          * @param string $style URL to the file
3712          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3713          * @return string HTML fragment
3714          */
3715         protected function styleLink( $style, array $options ) {
3716                 if ( isset( $options['dir'] ) ) {
3717                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3718                                 return '';
3719                         }
3720                 }
3721
3722                 if ( isset( $options['media'] ) ) {
3723                         $media = self::transformCssMedia( $options['media'] );
3724                         if ( is_null( $media ) ) {
3725                                 return '';
3726                         }
3727                 } else {
3728                         $media = 'all';
3729                 }
3730
3731                 if ( substr( $style, 0, 1 ) == '/' ||
3732                         substr( $style, 0, 5 ) == 'http:' ||
3733                         substr( $style, 0, 6 ) == 'https:' ) {
3734                         $url = $style;
3735                 } else {
3736                         $config = $this->getConfig();
3737                         $url = $config->get( 'StylePath' ) . '/' . $style . '?' .
3738                                 $config->get( 'StyleVersion' );
3739                 }
3740
3741                 $link = Html::linkedStyle( $url, $media );
3742
3743                 if ( isset( $options['condition'] ) ) {
3744                         $condition = htmlspecialchars( $options['condition'] );
3745                         $link = "<!--[if $condition]>$link<![endif]-->";
3746                 }
3747                 return $link;
3748         }
3749
3750         /**
3751          * Transform path to web-accessible static resource.
3752          *
3753          * This is used to add a validation hash as query string.
3754          * This aids various behaviors:
3755          *
3756          * - Put long Cache-Control max-age headers on responses for improved
3757          *   cache performance.
3758          * - Get the correct version of a file as expected by the current page.
3759          * - Instantly get the updated version of a file after deployment.
3760          *
3761          * Avoid using this for urls included in HTML as otherwise clients may get different
3762          * versions of a resource when navigating the site depending on when the page was cached.
3763          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3764          * an external stylesheet).
3765          *
3766          * @since 1.27
3767          * @param Config $config
3768          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3769          * @return string URL
3770          */
3771         public static function transformResourcePath( Config $config, $path ) {
3772                 global $IP;
3773
3774                 $localDir = $IP;
3775                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3776                 if ( $remotePathPrefix === '' ) {
3777                         // The configured base path is required to be empty string for
3778                         // wikis in the domain root
3779                         $remotePath = '/';
3780                 } else {
3781                         $remotePath = $remotePathPrefix;
3782                 }
3783                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3784                         // - Path is outside wgResourceBasePath, ignore.
3785                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3786                         return $path;
3787                 }
3788                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3789                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3790                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3791                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3792                 $uploadPath = $config->get( 'UploadPath' );
3793                 if ( strpos( $path, $uploadPath ) === 0 ) {
3794                         $localDir = $config->get( 'UploadDirectory' );
3795                         $remotePathPrefix = $remotePath = $uploadPath;
3796                 }
3797
3798                 $path = RelPath\getRelativePath( $path, $remotePath );
3799                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3800         }
3801
3802         /**
3803          * Utility method for transformResourceFilePath().
3804          *
3805          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3806          *
3807          * @since 1.27
3808          * @param string $remotePathPrefix URL path prefix that points to $localPath
3809          * @param string $localPath File directory exposed at $remotePath
3810          * @param string $file Path to target file relative to $localPath
3811          * @return string URL
3812          */
3813         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3814                 $hash = md5_file( "$localPath/$file" );
3815                 if ( $hash === false ) {
3816                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3817                         $hash = '';
3818                 }
3819                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3820         }
3821
3822         /**
3823          * Transform "media" attribute based on request parameters
3824          *
3825          * @param string $media Current value of the "media" attribute
3826          * @return string Modified value of the "media" attribute, or null to skip
3827          * this stylesheet
3828          */
3829         public static function transformCssMedia( $media ) {
3830                 global $wgRequest;
3831
3832                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3833                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3834
3835                 // Switch in on-screen display for media testing
3836                 $switches = [
3837                         'printable' => 'print',
3838                         'handheld' => 'handheld',
3839                 ];
3840                 foreach ( $switches as $switch => $targetMedia ) {
3841                         if ( $wgRequest->getBool( $switch ) ) {
3842                                 if ( $media == $targetMedia ) {
3843                                         $media = '';
3844                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3845                                         /* This regex will not attempt to understand a comma-separated media_query_list
3846                                          *
3847                                          * Example supported values for $media:
3848                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3849                                          * Example NOT supported value for $media:
3850                                          * '3d-glasses, screen, print and resolution > 90dpi'
3851                                          *
3852                                          * If it's a print request, we never want any kind of screen stylesheets
3853                                          * If it's a handheld request (currently the only other choice with a switch),
3854                                          * we don't want simple 'screen' but we might want screen queries that
3855                                          * have a max-width or something, so we'll pass all others on and let the
3856                                          * client do the query.
3857                                          */
3858                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3859                                                 return null;
3860                                         }
3861                                 }
3862                         }
3863                 }
3864
3865                 return $media;
3866         }
3867
3868         /**
3869          * Add a wikitext-formatted message to the output.
3870          * This is equivalent to:
3871          *
3872          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3873          */
3874         public function addWikiMsg( /*...*/ ) {
3875                 $args = func_get_args();
3876                 $name = array_shift( $args );
3877                 $this->addWikiMsgArray( $name, $args );
3878         }
3879
3880         /**
3881          * Add a wikitext-formatted message to the output.
3882          * Like addWikiMsg() except the parameters are taken as an array
3883          * instead of a variable argument list.
3884          *
3885          * @param string $name
3886          * @param array $args
3887          */
3888         public function addWikiMsgArray( $name, $args ) {
3889                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3890         }
3891
3892         /**
3893          * This function takes a number of message/argument specifications, wraps them in
3894          * some overall structure, and then parses the result and adds it to the output.
3895          *
3896          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3897          * and so on. The subsequent arguments may be either
3898          * 1) strings, in which case they are message names, or
3899          * 2) arrays, in which case, within each array, the first element is the message
3900          *    name, and subsequent elements are the parameters to that message.
3901          *
3902          * Don't use this for messages that are not in the user's interface language.
3903          *
3904          * For example:
3905          *
3906          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3907          *
3908          * Is equivalent to:
3909          *
3910          *    $wgOut->addWikiText( "<div class='error'>\n"
3911          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3912          *
3913          * The newline after the opening div is needed in some wikitext. See T21226.
3914          *
3915          * @param string $wrap
3916          */
3917         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3918                 $msgSpecs = func_get_args();
3919                 array_shift( $msgSpecs );
3920                 $msgSpecs = array_values( $msgSpecs );
3921                 $s = $wrap;
3922                 foreach ( $msgSpecs as $n => $spec ) {
3923                         if ( is_array( $spec ) ) {
3924                                 $args = $spec;
3925                                 $name = array_shift( $args );
3926                                 if ( isset( $args['options'] ) ) {
3927                                         unset( $args['options'] );
3928                                         wfDeprecated(
3929                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3930                                                 '1.20'
3931                                         );
3932                                 }
3933                         } else {
3934                                 $args = [];
3935                                 $name = $spec;
3936                         }
3937                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3938                 }
3939                 $this->addWikiText( $s );
3940         }
3941
3942         /**
3943          * Whether the output has a table of contents
3944          * @return bool
3945          * @since 1.22
3946          */
3947         public function isTOCEnabled() {
3948                 return $this->mEnableTOC;
3949         }
3950
3951         /**
3952          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3953          * @param bool $flag
3954          * @since 1.23
3955          */
3956         public function enableSectionEditLinks( $flag = true ) {
3957                 $this->mEnableSectionEditLinks = $flag;
3958         }
3959
3960         /**
3961          * @return bool
3962          * @since 1.23
3963          */
3964         public function sectionEditLinksEnabled() {
3965                 return $this->mEnableSectionEditLinks;
3966         }
3967
3968         /**
3969          * Helper function to setup the PHP implementation of OOUI to use in this request.
3970          *
3971          * @since 1.26
3972          * @param String $skinName The Skin name to determine the correct OOUI theme
3973          * @param String $dir Language direction
3974          */
3975         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
3976                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
3977                 $theme = isset( $themes[$skinName] ) ? $themes[$skinName] : $themes['default'];
3978                 // For example, 'OOUI\WikimediaUITheme'.
3979                 $themeClass = "OOUI\\{$theme}Theme";
3980                 OOUI\Theme::setSingleton( new $themeClass() );
3981                 OOUI\Element::setDefaultDir( $dir );
3982         }
3983
3984         /**
3985          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3986          * MediaWiki and this OutputPage instance.
3987          *
3988          * @since 1.25
3989          */
3990         public function enableOOUI() {
3991                 self::setupOOUI(
3992                         strtolower( $this->getSkin()->getSkinName() ),
3993                         $this->getLanguage()->getDir()
3994                 );
3995                 $this->addModuleStyles( [
3996                         'oojs-ui-core.styles',
3997                         'oojs-ui.styles.indicators',
3998                         'oojs-ui.styles.textures',
3999                         'mediawiki.widgets.styles',
4000                         'oojs-ui.styles.icons-content',
4001                         'oojs-ui.styles.icons-alerts',
4002                         'oojs-ui.styles.icons-interactions',
4003                 ] );
4004         }
4005
4006         /**
4007          * Add Link headers for preloading the wiki's logo.
4008          *
4009          * @since 1.26
4010          */
4011         protected function addLogoPreloadLinkHeaders() {
4012                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
4013
4014                 $tags = [];
4015                 $logosPerDppx = [];
4016                 $logos = [];
4017
4018                 if ( !is_array( $logo ) ) {
4019                         // No media queries required if we only have one variant
4020                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
4021                         return;
4022                 }
4023
4024                 if ( isset( $logo['svg'] ) ) {
4025                         // No media queries required if we only have a 1x and svg variant
4026                         // because all preload-capable browsers support SVGs
4027                         $this->addLinkHeader( '<' . $logo['svg'] . '>;rel=preload;as=image' );
4028                         return;
4029                 }
4030
4031                 foreach ( $logo as $dppx => $src ) {
4032                         // Keys are in this format: "1.5x"
4033                         $dppx = substr( $dppx, 0, -1 );
4034                         $logosPerDppx[$dppx] = $src;
4035                 }
4036
4037                 // Because PHP can't have floats as array keys
4038                 uksort( $logosPerDppx, function ( $a , $b ) {
4039                         $a = floatval( $a );
4040                         $b = floatval( $b );
4041
4042                         if ( $a == $b ) {
4043                                 return 0;
4044                         }
4045                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
4046                         return ( $a < $b ) ? -1 : 1;
4047                 } );
4048
4049                 foreach ( $logosPerDppx as $dppx => $src ) {
4050                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
4051                 }
4052
4053                 $logosCount = count( $logos );
4054                 // Logic must match ResourceLoaderSkinModule:
4055                 // - 1x applies to resolution < 1.5dppx
4056                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
4057                 // - 2x applies to resolution >= 2dppx
4058                 // Note that min-resolution and max-resolution are both inclusive.
4059                 for ( $i = 0; $i < $logosCount; $i++ ) {
4060                         if ( $i === 0 ) {
4061                                 // Smallest dppx
4062                                 // min-resolution is ">=" (larger than or equal to)
4063                                 // "not min-resolution" is essentially "<"
4064                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
4065                         } elseif ( $i !== $logosCount - 1 ) {
4066                                 // In between
4067                                 // Media query expressions can only apply "not" to the entire expression
4068                                 // (e.g. can't express ">= 1.5 and not >= 2).
4069                                 // Workaround: Use <= 1.9999 in place of < 2.
4070                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
4071                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
4072                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
4073                         } else {
4074                                 // Largest dppx
4075                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
4076                         }
4077
4078                         $this->addLinkHeader(
4079                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
4080                         );
4081                 }
4082         }
4083 }