includes/OutputPage.php

   1 <?php
   2 /**
   3  * Preparation for the final page rendering.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use MediaWiki\Linker\LinkTarget;
  24 use MediaWiki\Logger\LoggerFactory;
  25 use MediaWiki\MediaWikiServices;
  26 use MediaWiki\Session\SessionManager;
  27 use Wikimedia\RelPath;
  28 use Wikimedia\WrappedString;
  29 use Wikimedia\WrappedStringList;
  30
  31 /**
  32  * This class should be covered by a general architecture document which does
  33  * not exist as of January 2011.  This is one of the Core classes and should
  34  * be read at least once by any new developers.
  35  *
  36  * This class is used to prepare the final rendering. A skin is then
  37  * applied to the output parameters (links, javascript, html, categories ...).
  38  *
  39  * @todo FIXME: Another class handles sending the whole page to the client.
  40  *
  41  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  42  * in November 2010.
  43  *
  44  * @todo document
  45  */
  46 class OutputPage extends ContextSource {
  47         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  48         protected $mMetatags = [];
  49
  50         /** @var array */
  51         protected $mLinktags = [];
  52
  53         /** @var bool */
  54         protected $mCanonicalUrl = false;
  55
  56         /**
  57          * @var string Should be private - has getter and setter. Contains
  58          *   the HTML title */
  59         public $mPagetitle = '';
  60
  61         /**
  62          * @var string Contains all of the "<body>" content. Should be private we
  63          *   got set/get accessors and the append() method.
  64          */
  65         public $mBodytext = '';
  66
  67         /** @var string Stores contents of "<title>" tag */
  68         private $mHTMLtitle = '';
  69
  70         /**
  71          * @var bool Is the displayed content related to the source of the
  72          *   corresponding wiki article.
  73          */
  74         private $mIsarticle = false;
  75
  76         /** @var bool Stores "article flag" toggle. */
  77         private $mIsArticleRelated = true;
  78
  79         /**
  80          * @var bool We have to set isPrintable(). Some pages should
  81          * never be printed (ex: redirections).
  82          */
  83         private $mPrintable = false;
  84
  85         /**
  86          * @var array Contains the page subtitle. Special pages usually have some
  87          *   links here. Don't confuse with site subtitle added by skins.
  88          */
  89         private $mSubtitle = [];
  90
  91         /** @var string */
  92         public $mRedirect = '';
  93
  94         /** @var int */
  95         protected $mStatusCode;
  96
  97         /**
  98          * @var string Used for sending cache control.
  99          *   The whole caching system should probably be moved into its own class.
 100          */
 101         protected $mLastModified = '';
 102
 103         /** @var array */
 104         protected $mCategoryLinks = [];
 105
 106         /** @var array */
 107         protected $mCategories = [
 108                 'hidden' => [],
 109                 'normal' => [],
 110         ];
 111
 112         /** @var array */
 113         protected $mIndicators = [];
 114
 115         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 116         private $mLanguageLinks = [];
 117
 118         /**
 119          * Used for JavaScript (predates ResourceLoader)
 120          * @todo We should split JS / CSS.
 121          * mScripts content is inserted as is in "<head>" by Skin. This might
 122          * contain either a link to a stylesheet or inline CSS.
 123          */
 124         private $mScripts = '';
 125
 126         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 127         protected $mInlineStyles = '';
 128
 129         /**
 130          * @var string Used by skin template.
 131          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 132          */
 133         public $mPageLinkTitle = '';
 134
 135         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 136         protected $mHeadItems = [];
 137
 138         /** @var array Additional <body> classes; there are also <body> classes from other sources */
 139         protected $mAdditionalBodyClasses = [];
 140
 141         /** @var array */
 142         protected $mModules = [];
 143
 144         /** @var array */
 145         protected $mModuleScripts = [];
 146
 147         /** @var array */
 148         protected $mModuleStyles = [];
 149
 150         /** @var ResourceLoader */
 151         protected $mResourceLoader;
 152
 153         /** @var ResourceLoaderClientHtml */
 154         private $rlClient;
 155
 156         /** @var ResourceLoaderContext */
 157         private $rlClientContext;
 158
 159         /** @var array */
 160         private $rlExemptStyleModules;
 161
 162         /** @var array */
 163         protected $mJsConfigVars = [];
 164
 165         /** @var array */
 166         protected $mTemplateIds = [];
 167
 168         /** @var array */
 169         protected $mImageTimeKeys = [];
 170
 171         /** @var string */
 172         public $mRedirectCode = '';
 173
 174         protected $mFeedLinksAppendQuery = null;
 175
 176         /** @var array
 177          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 178          * @see ResourceLoaderModule::$origin
 179          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 180          */
 181         protected $mAllowedModules = [
 182                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 183         ];
 184
 185         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 186         protected $mDoNothing = false;
 187
 188         // Parser related.
 189
 190         /** @var int */
 191         protected $mContainsNewMagic = 0;
 192
 193         /**
 194          * lazy initialised, use parserOptions()
 195          * @var ParserOptions
 196          */
 197         protected $mParserOptions = null;
 198
 199         /**
 200          * Handles the Atom / RSS links.
 201          * We probably only support Atom in 2011.
 202          * @see $wgAdvertisedFeedTypes
 203          */
 204         private $mFeedLinks = [];
 205
 206         // Gwicke work on squid caching? Roughly from 2003.
 207         protected $mEnableClientCache = true;
 208
 209         /** @var bool Flag if output should only contain the body of the article. */
 210         private $mArticleBodyOnly = false;
 211
 212         /** @var bool */
 213         protected $mNewSectionLink = false;
 214
 215         /** @var bool */
 216         protected $mHideNewSectionLink = false;
 217
 218         /**
 219          * @var bool Comes from the parser. This was probably made to load CSS/JS
 220          * only if we had "<gallery>". Used directly in CategoryPage.php.
 221          * Looks like ResourceLoader can replace this.
 222          */
 223         public $mNoGallery = false;
 224
 225         /** @var string */
 226         private $mPageTitleActionText = '';
 227
 228         /** @var int Cache stuff. Looks like mEnableClientCache */
 229         protected $mCdnMaxage = 0;
 230         /** @var int Upper limit on mCdnMaxage */
 231         protected $mCdnMaxageLimit = INF;
 232
 233         /**
 234          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 235          * be sent. This should be done for pages where edit actions are possible.
 236          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 237          */
 238         protected $mPreventClickjacking = true;
 239
 240         /** @var int To include the variable {{REVISIONID}} */
 241         private $mRevisionId = null;
 242
 243         /** @var string */
 244         private $mRevisionTimestamp = null;
 245
 246         /** @var array */
 247         protected $mFileVersion = null;
 248
 249         /**
 250          * @var array An array of stylesheet filenames (relative from skins path),
 251          * with options for CSS media, IE conditions, and RTL/LTR direction.
 252          * For internal use; add settings in the skin via $this->addStyle()
 253          *
 254          * Style again! This seems like a code duplication since we already have
 255          * mStyles. This is what makes Open Source amazing.
 256          */
 257         protected $styles = [];
 258
 259         private $mIndexPolicy = 'index';
 260         private $mFollowPolicy = 'follow';
 261         private $mVaryHeader = [
 262                 'Accept-Encoding' => [ 'match=gzip' ],
 263         ];
 264
 265         /**
 266          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 267          * of the redirect.
 268          *
 269          * @var Title
 270          */
 271         private $mRedirectedFrom = null;
 272
 273         /**
 274          * Additional key => value data
 275          */
 276         private $mProperties = [];
 277
 278         /**
 279          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 280          */
 281         private $mTarget = null;
 282
 283         /**
 284          * @var bool Whether parser output contains a table of contents
 285          */
 286         private $mEnableTOC = false;
 287
 288         /**
 289          * @var string|null The URL to send in a <link> element with rel=license
 290          */
 291         private $copyrightUrl;
 292
 293         /** @var array Profiling data */
 294         private $limitReportJSData = [];
 295
 296         /** @var array Map Title to Content */
 297         private $contentOverrides = [];
 298
 299         /** @var callable[] */
 300         private $contentOverrideCallbacks = [];
 301
 302         /**
 303          * Link: header contents
 304          */
 305         private $mLinkHeader = [];
 306
 307         /**
 308          * @var string The nonce for Content-Security-Policy
 309          */
 310         private $CSPNonce;
 311
 312         /**
 313          * Constructor for OutputPage. This should not be called directly.
 314          * Instead a new RequestContext should be created and it will implicitly create
 315          * a OutputPage tied to that context.
 316          * @param IContextSource $context
 317          */
 318         function __construct( IContextSource $context ) {
 319                 $this->setContext( $context );
 320         }
 321
 322         /**
 323          * Redirect to $url rather than displaying the normal page
 324          *
 325          * @param string $url
 326          * @param string $responsecode HTTP status code
 327          */
 328         public function redirect( $url, $responsecode = '302' ) {
 329                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 330                 $this->mRedirect = str_replace( "\n", '', $url );
 331                 $this->mRedirectCode = $responsecode;
 332         }
 333
 334         /**
 335          * Get the URL to redirect to, or an empty string if not redirect URL set
 336          *
 337          * @return string
 338          */
 339         public function getRedirect() {
 340                 return $this->mRedirect;
 341         }
 342
 343         /**
 344          * Set the copyright URL to send with the output.
 345          * Empty string to omit, null to reset.
 346          *
 347          * @since 1.26
 348          *
 349          * @param string|null $url
 350          */
 351         public function setCopyrightUrl( $url ) {
 352                 $this->copyrightUrl = $url;
 353         }
 354
 355         /**
 356          * Set the HTTP status code to send with the output.
 357          *
 358          * @param int $statusCode
 359          */
 360         public function setStatusCode( $statusCode ) {
 361                 $this->mStatusCode = $statusCode;
 362         }
 363
 364         /**
 365          * Add a new "<meta>" tag
 366          * To add an http-equiv meta tag, precede the name with "http:"
 367          *
 368          * @param string $name Name of the meta tag
 369          * @param string $val Value of the meta tag
 370          */
 371         function addMeta( $name, $val ) {
 372                 array_push( $this->mMetatags, [ $name, $val ] );
 373         }
 374
 375         /**
 376          * Returns the current <meta> tags
 377          *
 378          * @since 1.25
 379          * @return array
 380          */
 381         public function getMetaTags() {
 382                 return $this->mMetatags;
 383         }
 384
 385         /**
 386          * Add a new \<link\> tag to the page header.
 387          *
 388          * Note: use setCanonicalUrl() for rel=canonical.
 389          *
 390          * @param array $linkarr Associative array of attributes.
 391          */
 392         function addLink( array $linkarr ) {
 393                 array_push( $this->mLinktags, $linkarr );
 394         }
 395
 396         /**
 397          * Returns the current <link> tags
 398          *
 399          * @since 1.25
 400          * @return array
 401          */
 402         public function getLinkTags() {
 403                 return $this->mLinktags;
 404         }
 405
 406         /**
 407          * Add a new \<link\> with "rel" attribute set to "meta"
 408          *
 409          * @param array $linkarr Associative array mapping attribute names to their
 410          *                 values, both keys and values will be escaped, and the
 411          *                 "rel" attribute will be automatically added
 412          */
 413         function addMetadataLink( array $linkarr ) {
 414                 $linkarr['rel'] = $this->getMetadataAttribute();
 415                 $this->addLink( $linkarr );
 416         }
 417
 418         /**
 419          * Set the URL to be used for the <link rel=canonical>. This should be used
 420          * in preference to addLink(), to avoid duplicate link tags.
 421          * @param string $url
 422          */
 423         function setCanonicalUrl( $url ) {
 424                 $this->mCanonicalUrl = $url;
 425         }
 426
 427         /**
 428          * Returns the URL to be used for the <link rel=canonical> if
 429          * one is set.
 430          *
 431          * @since 1.25
 432          * @return bool|string
 433          */
 434         public function getCanonicalUrl() {
 435                 return $this->mCanonicalUrl;
 436         }
 437
 438         /**
 439          * Get the value of the "rel" attribute for metadata links
 440          *
 441          * @return string
 442          */
 443         public function getMetadataAttribute() {
 444                 # note: buggy CC software only reads first "meta" link
 445                 static $haveMeta = false;
 446                 if ( $haveMeta ) {
 447                         return 'alternate meta';
 448                 } else {
 449                         $haveMeta = true;
 450                         return 'meta';
 451                 }
 452         }
 453
 454         /**
 455          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 456          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 457          * if possible.
 458          *
 459          * @param string $script Raw HTML
 460          */
 461         function addScript( $script ) {
 462                 $this->mScripts .= $script;
 463         }
 464
 465         /**
 466          * Add a JavaScript file to be loaded as `<script>` on this page.
 467          *
 468          * Internal use only. Use OutputPage::addModules() if possible.
 469          *
 470          * @param string $file URL to file (absolute path, protocol-relative, or full url)
 471          * @param string $version Style version of the file. Defaults to $wgStyleVersion
 472          */
 473         public function addScriptFile( $file, $version = null ) {
 474                 if ( substr( $file, 0, 1 ) !== '/' && !preg_match( '#^[a-z]*://#i', $file ) ) {
 475                         // This is not an absolute path, protocol-relative url, or full scheme url,
 476                         // presumed to be an old call intended to include a file from /w/skins/common,
 477                         // which doesn't exist anymore as of MediaWiki 1.24 per T71277. Ignore.
 478                         wfDeprecated( __METHOD__, '1.24' );
 479                         return;
 480                 }
 481                 $path = $file;
 482                 if ( is_null( $version ) ) {
 483                         $version = $this->getConfig()->get( 'StyleVersion' );
 484                 }
 485                 $this->addScript( Html::linkedScript( wfAppendQuery( $path, $version ), $this->getCSPNonce() ) );
 486         }
 487
 488         /**
 489          * Add a self-contained script tag with the given contents
 490          * Internal use only. Use OutputPage::addModules() if possible.
 491          *
 492          * @param string $script JavaScript text, no script tags
 493          */
 494         public function addInlineScript( $script ) {
 495                 $this->mScripts .= Html::inlineScript( "\n$script\n", $this->getCSPNonce() ) . "\n";
 496         }
 497
 498         /**
 499          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 500          * which are no longer registered (eg a page is cached before an extension is disabled)
 501          * @param array $modules
 502          * @param string|null $position Unused
 503          * @param string $type
 504          * @return array
 505          */
 506         protected function filterModules( array $modules, $position = null,
 507                 $type = ResourceLoaderModule::TYPE_COMBINED
 508         ) {
 509                 $resourceLoader = $this->getResourceLoader();
 510                 $filteredModules = [];
 511                 foreach ( $modules as $val ) {
 512                         $module = $resourceLoader->getModule( $val );
 513                         if ( $module instanceof ResourceLoaderModule
 514                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 515                         ) {
 516                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 517                                         $this->warnModuleTargetFilter( $module->getName() );
 518                                         continue;
 519                                 }
 520                                 $filteredModules[] = $val;
 521                         }
 522                 }
 523                 return $filteredModules;
 524         }
 525
 526         private function warnModuleTargetFilter( $moduleName ) {
 527                 static $warnings = [];
 528                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 529                         return;
 530                 }
 531                 $warnings[$this->mTarget][$moduleName] = true;
 532                 $this->getResourceLoader()->getLogger()->debug(
 533                         'Module "{module}" not loadable on target "{target}".',
 534                         [
 535                                 'module' => $moduleName,
 536                                 'target' => $this->mTarget,
 537                         ]
 538                 );
 539         }
 540
 541         /**
 542          * Get the list of modules to include on this page
 543          *
 544          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 545          * @param string|null $position Unused
 546          * @param string $param
 547          * @param string $type
 548          * @return array Array of module names
 549          */
 550         public function getModules( $filter = false, $position = null, $param = 'mModules',
 551                 $type = ResourceLoaderModule::TYPE_COMBINED
 552         ) {
 553                 $modules = array_values( array_unique( $this->$param ) );
 554                 return $filter
 555                         ? $this->filterModules( $modules, null, $type )
 556                         : $modules;
 557         }
 558
 559         /**
 560          * Load one or more ResourceLoader modules on this page.
 561          *
 562          * @param string|array $modules Module name (string) or array of module names
 563          */
 564         public function addModules( $modules ) {
 565                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 566         }
 567
 568         /**
 569          * Get the list of script-only modules to load on this page.
 570          *
 571          * @param bool $filter
 572          * @param string|null $position Unused
 573          * @return array Array of module names
 574          */
 575         public function getModuleScripts( $filter = false, $position = null ) {
 576                 return $this->getModules( $filter, null, 'mModuleScripts',
 577                         ResourceLoaderModule::TYPE_SCRIPTS
 578                 );
 579         }
 580
 581         /**
 582          * Load the scripts of one or more ResourceLoader modules, on this page.
 583          *
 584          * This method exists purely to provide the legacy behaviour of loading
 585          * a module's scripts in the global scope, and without dependency resolution.
 586          * See <https://phabricator.wikimedia.org/T188689>.
 587          *
 588          * @deprecated since 1.31 Use addModules() instead.
 589          * @param string|array $modules Module name (string) or array of module names
 590          */
 591         public function addModuleScripts( $modules ) {
 592                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 593         }
 594
 595         /**
 596          * Get the list of style-only modules to load on this page.
 597          *
 598          * @param bool $filter
 599          * @param string|null $position Unused
 600          * @return array Array of module names
 601          */
 602         public function getModuleStyles( $filter = false, $position = null ) {
 603                 return $this->getModules( $filter, null, 'mModuleStyles',
 604                         ResourceLoaderModule::TYPE_STYLES
 605                 );
 606         }
 607
 608         /**
 609          * Load the styles of one or more ResourceLoader modules on this page.
 610          *
 611          * Module styles added through this function will be loaded as a stylesheet,
 612          * using a standard `<link rel=stylesheet>` HTML tag, rather than as a combined
 613          * Javascript and CSS package. Thus, they will even load when JavaScript is disabled.
 614          *
 615          * @param string|array $modules Module name (string) or array of module names
 616          */
 617         public function addModuleStyles( $modules ) {
 618                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 619         }
 620
 621         /**
 622          * @return null|string ResourceLoader target
 623          */
 624         public function getTarget() {
 625                 return $this->mTarget;
 626         }
 627
 628         /**
 629          * Sets ResourceLoader target for load.php links. If null, will be omitted
 630          *
 631          * @param string|null $target
 632          */
 633         public function setTarget( $target ) {
 634                 $this->mTarget = $target;
 635         }
 636
 637         /**
 638          * Add a mapping from a LinkTarget to a Content, for things like page preview.
 639          * @see self::addContentOverrideCallback()
 640          * @since 1.32
 641          * @param LinkTarget $target
 642          * @param Content $content
 643          */
 644         public function addContentOverride( LinkTarget $target, Content $content ) {
 645                 if ( !$this->contentOverrides ) {
 646                         // Register a callback for $this->contentOverrides on the first call
 647                         $this->addContentOverrideCallback( function ( LinkTarget $target ) {
 648                                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 649                                 return isset( $this->contentOverrides[$key] )
 650                                         ? $this->contentOverrides[$key]
 651                                         : null;
 652                         } );
 653                 }
 654
 655                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 656                 $this->contentOverrides[$key] = $content;
 657         }
 658
 659         /**
 660          * Add a callback for mapping from a Title to a Content object, for things
 661          * like page preview.
 662          * @see ResourceLoaderContext::getContentOverrideCallback()
 663          * @since 1.32
 664          * @param callable $callback
 665          */
 666         public function addContentOverrideCallback( callable $callback ) {
 667                 $this->contentOverrideCallbacks[] = $callback;
 668         }
 669
 670         /**
 671          * Get an array of head items
 672          *
 673          * @return array
 674          */
 675         function getHeadItemsArray() {
 676                 return $this->mHeadItems;
 677         }
 678
 679         /**
 680          * Add or replace a head item to the output
 681          *
 682          * Whenever possible, use more specific options like ResourceLoader modules,
 683          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 684          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 685          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 686          * This would be your very LAST fallback.
 687          *
 688          * @param string $name Item name
 689          * @param string $value Raw HTML
 690          */
 691         public function addHeadItem( $name, $value ) {
 692                 $this->mHeadItems[$name] = $value;
 693         }
 694
 695         /**
 696          * Add one or more head items to the output
 697          *
 698          * @since 1.28
 699          * @param string|string[] $values Raw HTML
 700          */
 701         public function addHeadItems( $values ) {
 702                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 703         }
 704
 705         /**
 706          * Check if the header item $name is already set
 707          *
 708          * @param string $name Item name
 709          * @return bool
 710          */
 711         public function hasHeadItem( $name ) {
 712                 return isset( $this->mHeadItems[$name] );
 713         }
 714
 715         /**
 716          * Add a class to the <body> element
 717          *
 718          * @since 1.30
 719          * @param string|string[] $classes One or more classes to add
 720          */
 721         public function addBodyClasses( $classes ) {
 722                 $this->mAdditionalBodyClasses = array_merge( $this->mAdditionalBodyClasses, (array)$classes );
 723         }
 724
 725         /**
 726          * Set whether the output should only contain the body of the article,
 727          * without any skin, sidebar, etc.
 728          * Used e.g. when calling with "action=render".
 729          *
 730          * @param bool $only Whether to output only the body of the article
 731          */
 732         public function setArticleBodyOnly( $only ) {
 733                 $this->mArticleBodyOnly = $only;
 734         }
 735
 736         /**
 737          * Return whether the output will contain only the body of the article
 738          *
 739          * @return bool
 740          */
 741         public function getArticleBodyOnly() {
 742                 return $this->mArticleBodyOnly;
 743         }
 744
 745         /**
 746          * Set an additional output property
 747          * @since 1.21
 748          *
 749          * @param string $name
 750          * @param mixed $value
 751          */
 752         public function setProperty( $name, $value ) {
 753                 $this->mProperties[$name] = $value;
 754         }
 755
 756         /**
 757          * Get an additional output property
 758          * @since 1.21
 759          *
 760          * @param string $name
 761          * @return mixed Property value or null if not found
 762          */
 763         public function getProperty( $name ) {
 764                 if ( isset( $this->mProperties[$name] ) ) {
 765                         return $this->mProperties[$name];
 766                 } else {
 767                         return null;
 768                 }
 769         }
 770
 771         /**
 772          * checkLastModified tells the client to use the client-cached page if
 773          * possible. If successful, the OutputPage is disabled so that
 774          * any future call to OutputPage->output() have no effect.
 775          *
 776          * Side effect: sets mLastModified for Last-Modified header
 777          *
 778          * @param string $timestamp
 779          *
 780          * @return bool True if cache-ok headers was sent.
 781          */
 782         public function checkLastModified( $timestamp ) {
 783                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 784                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 785                         return false;
 786                 }
 787                 $config = $this->getConfig();
 788                 if ( !$config->get( 'CachePages' ) ) {
 789                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 790                         return false;
 791                 }
 792
 793                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 794                 $modifiedTimes = [
 795                         'page' => $timestamp,
 796                         'user' => $this->getUser()->getTouched(),
 797                         'epoch' => $config->get( 'CacheEpoch' )
 798                 ];
 799                 if ( $config->get( 'UseSquid' ) ) {
 800                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, $this->getCdnCacheEpoch(
 801                                 time(),
 802                                 $config->get( 'SquidMaxage' )
 803                         ) );
 804                 }
 805                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 806
 807                 $maxModified = max( $modifiedTimes );
 808                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 809
 810                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 811                 if ( $clientHeader === false ) {
 812                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 813                         return false;
 814                 }
 815
 816                 # IE sends sizes after the date like this:
 817                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 818                 # this breaks strtotime().
 819                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 820
 821                 Wikimedia\suppressWarnings(); // E_STRICT system time bitching
 822                 $clientHeaderTime = strtotime( $clientHeader );
 823                 Wikimedia\restoreWarnings();
 824                 if ( !$clientHeaderTime ) {
 825                         wfDebug( __METHOD__
 826                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 827                         return false;
 828                 }
 829                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 830
 831                 # Make debug info
 832                 $info = '';
 833                 foreach ( $modifiedTimes as $name => $value ) {
 834                         if ( $info !== '' ) {
 835                                 $info .= ', ';
 836                         }
 837                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 838                 }
 839
 840                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 841                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 842                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 843                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 844                 if ( $clientHeaderTime < $maxModified ) {
 845                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 846                         return false;
 847                 }
 848
 849                 # Not modified
 850                 # Give a 304 Not Modified response code and disable body output
 851                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 852                 ini_set( 'zlib.output_compression', 0 );
 853                 $this->getRequest()->response()->statusHeader( 304 );
 854                 $this->sendCacheControl();
 855                 $this->disable();
 856
 857                 // Don't output a compressed blob when using ob_gzhandler;
 858                 // it's technically against HTTP spec and seems to confuse
 859                 // Firefox when the response gets split over two packets.
 860                 wfClearOutputBuffers();
 861
 862                 return true;
 863         }
 864
 865         /**
 866          * @param int $reqTime Time of request (eg. now)
 867          * @param int $maxAge Cache TTL in seconds
 868          * @return int Timestamp
 869          */
 870         private function getCdnCacheEpoch( $reqTime, $maxAge ) {
 871                 // Ensure Last-Modified is never more than (wgSquidMaxage) in the past,
 872                 // because even if the wiki page content hasn't changed since, static
 873                 // resources may have changed (skin HTML, interface messages, urls, etc.)
 874                 // and must roll-over in a timely manner (T46570)
 875                 return $reqTime - $maxAge;
 876         }
 877
 878         /**
 879          * Override the last modified timestamp
 880          *
 881          * @param string $timestamp New timestamp, in a format readable by
 882          *        wfTimestamp()
 883          */
 884         public function setLastModified( $timestamp ) {
 885                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 886         }
 887
 888         /**
 889          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 890          *
 891          * @param string $policy The literal string to output as the contents of
 892          *   the meta tag.  Will be parsed according to the spec and output in
 893          *   standardized form.
 894          * @return null
 895          */
 896         public function setRobotPolicy( $policy ) {
 897                 $policy = Article::formatRobotPolicy( $policy );
 898
 899                 if ( isset( $policy['index'] ) ) {
 900                         $this->setIndexPolicy( $policy['index'] );
 901                 }
 902                 if ( isset( $policy['follow'] ) ) {
 903                         $this->setFollowPolicy( $policy['follow'] );
 904                 }
 905         }
 906
 907         /**
 908          * Set the index policy for the page, but leave the follow policy un-
 909          * touched.
 910          *
 911          * @param string $policy Either 'index' or 'noindex'.
 912          * @return null
 913          */
 914         public function setIndexPolicy( $policy ) {
 915                 $policy = trim( $policy );
 916                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 917                         $this->mIndexPolicy = $policy;
 918                 }
 919         }
 920
 921         /**
 922          * Set the follow policy for the page, but leave the index policy un-
 923          * touched.
 924          *
 925          * @param string $policy Either 'follow' or 'nofollow'.
 926          * @return null
 927          */
 928         public function setFollowPolicy( $policy ) {
 929                 $policy = trim( $policy );
 930                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 931                         $this->mFollowPolicy = $policy;
 932                 }
 933         }
 934
 935         /**
 936          * Set the new value of the "action text", this will be added to the
 937          * "HTML title", separated from it with " - ".
 938          *
 939          * @param string $text New value of the "action text"
 940          */
 941         public function setPageTitleActionText( $text ) {
 942                 $this->mPageTitleActionText = $text;
 943         }
 944
 945         /**
 946          * Get the value of the "action text"
 947          *
 948          * @return string
 949          */
 950         public function getPageTitleActionText() {
 951                 return $this->mPageTitleActionText;
 952         }
 953
 954         /**
 955          * "HTML title" means the contents of "<title>".
 956          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 957          *
 958          * @param string|Message $name
 959          */
 960         public function setHTMLTitle( $name ) {
 961                 if ( $name instanceof Message ) {
 962                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 963                 } else {
 964                         $this->mHTMLtitle = $name;
 965                 }
 966         }
 967
 968         /**
 969          * Return the "HTML title", i.e. the content of the "<title>" tag.
 970          *
 971          * @return string
 972          */
 973         public function getHTMLTitle() {
 974                 return $this->mHTMLtitle;
 975         }
 976
 977         /**
 978          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 979          *
 980          * @param Title $t
 981          */
 982         public function setRedirectedFrom( $t ) {
 983                 $this->mRedirectedFrom = $t;
 984         }
 985
 986         /**
 987          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 988          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 989          * but not bad tags like \<script\>. This function automatically sets
 990          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 991          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 992          * good tags like \<i\> will be dropped entirely.
 993          *
 994          * @param string|Message $name
 995          */
 996         public function setPageTitle( $name ) {
 997                 if ( $name instanceof Message ) {
 998                         $name = $name->setContext( $this->getContext() )->text();
 999                 }
1000
1001                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
1002                 # but leave "<i>foobar</i>" alone
1003                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
1004                 $this->mPagetitle = $nameWithTags;
1005
1006                 # change "<i>foo&amp;bar</i>" to "foo&bar"
1007                 $this->setHTMLTitle(
1008                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
1009                                 ->inContentLanguage()
1010                 );
1011         }
1012
1013         /**
1014          * Return the "page title", i.e. the content of the \<h1\> tag.
1015          *
1016          * @return string
1017          */
1018         public function getPageTitle() {
1019                 return $this->mPagetitle;
1020         }
1021
1022         /**
1023          * Set the Title object to use
1024          *
1025          * @param Title $t
1026          */
1027         public function setTitle( Title $t ) {
1028                 $this->getContext()->setTitle( $t );
1029         }
1030
1031         /**
1032          * Replace the subtitle with $str
1033          *
1034          * @param string|Message $str New value of the subtitle. String should be safe HTML.
1035          */
1036         public function setSubtitle( $str ) {
1037                 $this->clearSubtitle();
1038                 $this->addSubtitle( $str );
1039         }
1040
1041         /**
1042          * Add $str to the subtitle
1043          *
1044          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
1045          */
1046         public function addSubtitle( $str ) {
1047                 if ( $str instanceof Message ) {
1048                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
1049                 } else {
1050                         $this->mSubtitle[] = $str;
1051                 }
1052         }
1053
1054         /**
1055          * Build message object for 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          * @return Message
1060          * @since 1.25
1061          */
1062         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1063                 if ( $title->isRedirect() ) {
1064                         $query['redirect'] = 'no';
1065                 }
1066                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1067                 return wfMessage( 'backlinksubtitle' )
1068                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1069         }
1070
1071         /**
1072          * Add a subtitle containing a backlink to a page
1073          *
1074          * @param Title $title Title to link to
1075          * @param array $query Array of additional parameters to include in the link
1076          */
1077         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1078                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1079         }
1080
1081         /**
1082          * Clear the subtitles
1083          */
1084         public function clearSubtitle() {
1085                 $this->mSubtitle = [];
1086         }
1087
1088         /**
1089          * Get the subtitle
1090          *
1091          * @return string
1092          */
1093         public function getSubtitle() {
1094                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1095         }
1096
1097         /**
1098          * Set the page as printable, i.e. it'll be displayed with all
1099          * print styles included
1100          */
1101         public function setPrintable() {
1102                 $this->mPrintable = true;
1103         }
1104
1105         /**
1106          * Return whether the page is "printable"
1107          *
1108          * @return bool
1109          */
1110         public function isPrintable() {
1111                 return $this->mPrintable;
1112         }
1113
1114         /**
1115          * Disable output completely, i.e. calling output() will have no effect
1116          */
1117         public function disable() {
1118                 $this->mDoNothing = true;
1119         }
1120
1121         /**
1122          * Return whether the output will be completely disabled
1123          *
1124          * @return bool
1125          */
1126         public function isDisabled() {
1127                 return $this->mDoNothing;
1128         }
1129
1130         /**
1131          * Show an "add new section" link?
1132          *
1133          * @return bool
1134          */
1135         public function showNewSectionLink() {
1136                 return $this->mNewSectionLink;
1137         }
1138
1139         /**
1140          * Forcibly hide the new section link?
1141          *
1142          * @return bool
1143          */
1144         public function forceHideNewSectionLink() {
1145                 return $this->mHideNewSectionLink;
1146         }
1147
1148         /**
1149          * Add or remove feed links in the page header
1150          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1151          * for the new version
1152          * @see addFeedLink()
1153          *
1154          * @param bool $show True: add default feeds, false: remove all feeds
1155          */
1156         public function setSyndicated( $show = true ) {
1157                 if ( $show ) {
1158                         $this->setFeedAppendQuery( false );
1159                 } else {
1160                         $this->mFeedLinks = [];
1161                 }
1162         }
1163
1164         /**
1165          * Add default feeds to the page header
1166          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1167          * for the new version
1168          * @see addFeedLink()
1169          *
1170          * @param string $val Query to append to feed links or false to output
1171          *        default links
1172          */
1173         public function setFeedAppendQuery( $val ) {
1174                 $this->mFeedLinks = [];
1175
1176                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1177                         $query = "feed=$type";
1178                         if ( is_string( $val ) ) {
1179                                 $query .= '&' . $val;
1180                         }
1181                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1182                 }
1183         }
1184
1185         /**
1186          * Add a feed link to the page header
1187          *
1188          * @param string $format Feed type, should be a key of $wgFeedClasses
1189          * @param string $href URL
1190          */
1191         public function addFeedLink( $format, $href ) {
1192                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1193                         $this->mFeedLinks[$format] = $href;
1194                 }
1195         }
1196
1197         /**
1198          * Should we output feed links for this page?
1199          * @return bool
1200          */
1201         public function isSyndicated() {
1202                 return count( $this->mFeedLinks ) > 0;
1203         }
1204
1205         /**
1206          * Return URLs for each supported syndication format for this page.
1207          * @return array Associating format keys with URLs
1208          */
1209         public function getSyndicationLinks() {
1210                 return $this->mFeedLinks;
1211         }
1212
1213         /**
1214          * Will currently always return null
1215          *
1216          * @return null
1217          */
1218         public function getFeedAppendQuery() {
1219                 return $this->mFeedLinksAppendQuery;
1220         }
1221
1222         /**
1223          * Set whether the displayed content is related to the source of the
1224          * corresponding article on the wiki
1225          * Setting true will cause the change "article related" toggle to true
1226          *
1227          * @param bool $v
1228          */
1229         public function setArticleFlag( $v ) {
1230                 $this->mIsarticle = $v;
1231                 if ( $v ) {
1232                         $this->mIsArticleRelated = $v;
1233                 }
1234         }
1235
1236         /**
1237          * Return whether the content displayed page is related to the source of
1238          * the corresponding article on the wiki
1239          *
1240          * @return bool
1241          */
1242         public function isArticle() {
1243                 return $this->mIsarticle;
1244         }
1245
1246         /**
1247          * Set whether this page is related an article on the wiki
1248          * Setting false will cause the change of "article flag" toggle to false
1249          *
1250          * @param bool $v
1251          */
1252         public function setArticleRelated( $v ) {
1253                 $this->mIsArticleRelated = $v;
1254                 if ( !$v ) {
1255                         $this->mIsarticle = false;
1256                 }
1257         }
1258
1259         /**
1260          * Return whether this page is related an article on the wiki
1261          *
1262          * @return bool
1263          */
1264         public function isArticleRelated() {
1265                 return $this->mIsArticleRelated;
1266         }
1267
1268         /**
1269          * Add new language links
1270          *
1271          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1272          *                               (e.g. 'fr:Test page')
1273          */
1274         public function addLanguageLinks( array $newLinkArray ) {
1275                 $this->mLanguageLinks += $newLinkArray;
1276         }
1277
1278         /**
1279          * Reset the language links and add new language links
1280          *
1281          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1282          *                               (e.g. 'fr:Test page')
1283          */
1284         public function setLanguageLinks( array $newLinkArray ) {
1285                 $this->mLanguageLinks = $newLinkArray;
1286         }
1287
1288         /**
1289          * Get the list of language links
1290          *
1291          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1292          */
1293         public function getLanguageLinks() {
1294                 return $this->mLanguageLinks;
1295         }
1296
1297         /**
1298          * Add an array of categories, with names in the keys
1299          *
1300          * @param array $categories Mapping category name => sort key
1301          */
1302         public function addCategoryLinks( array $categories ) {
1303                 global $wgContLang;
1304
1305                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1306                         return;
1307                 }
1308
1309                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1310
1311                 # Set all the values to 'normal'.
1312                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1313
1314                 # Mark hidden categories
1315                 foreach ( $res as $row ) {
1316                         if ( isset( $row->pp_value ) ) {
1317                                 $categories[$row->page_title] = 'hidden';
1318                         }
1319                 }
1320
1321                 // Avoid PHP 7.1 warning of passing $this by reference
1322                 $outputPage = $this;
1323                 # Add the remaining categories to the skin
1324                 if ( Hooks::run(
1325                         'OutputPageMakeCategoryLinks',
1326                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1327                 ) {
1328                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1329                         foreach ( $categories as $category => $type ) {
1330                                 // array keys will cast numeric category names to ints, so cast back to string
1331                                 $category = (string)$category;
1332                                 $origcategory = $category;
1333                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1334                                 if ( !$title ) {
1335                                         continue;
1336                                 }
1337                                 $wgContLang->findVariantLink( $category, $title, true );
1338                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1339                                         continue;
1340                                 }
1341                                 $text = $wgContLang->convertHtml( $title->getText() );
1342                                 $this->mCategories[$type][] = $title->getText();
1343                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1344                         }
1345                 }
1346         }
1347
1348         /**
1349          * @param array $categories
1350          * @return bool|ResultWrapper
1351          */
1352         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1353                 # Add the links to a LinkBatch
1354                 $arr = [ NS_CATEGORY => $categories ];
1355                 $lb = new LinkBatch;
1356                 $lb->setArray( $arr );
1357
1358                 # Fetch existence plus the hiddencat property
1359                 $dbr = wfGetDB( DB_REPLICA );
1360                 $fields = array_merge(
1361                         LinkCache::getSelectFields(),
1362                         [ 'page_namespace', 'page_title', 'pp_value' ]
1363                 );
1364
1365                 $res = $dbr->select( [ 'page', 'page_props' ],
1366                         $fields,
1367                         $lb->constructSet( 'page', $dbr ),
1368                         __METHOD__,
1369                         [],
1370                         [ 'page_props' => [ 'LEFT JOIN', [
1371                                 'pp_propname' => 'hiddencat',
1372                                 'pp_page = page_id'
1373                         ] ] ]
1374                 );
1375
1376                 # Add the results to the link cache
1377                 $lb->addResultToCache( LinkCache::singleton(), $res );
1378
1379                 return $res;
1380         }
1381
1382         /**
1383          * Reset the category links (but not the category list) and add $categories
1384          *
1385          * @param array $categories Mapping category name => sort key
1386          */
1387         public function setCategoryLinks( array $categories ) {
1388                 $this->mCategoryLinks = [];
1389                 $this->addCategoryLinks( $categories );
1390         }
1391
1392         /**
1393          * Get the list of category links, in a 2-D array with the following format:
1394          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1395          * hidden categories) and $link a HTML fragment with a link to the category
1396          * page
1397          *
1398          * @return array
1399          */
1400         public function getCategoryLinks() {
1401                 return $this->mCategoryLinks;
1402         }
1403
1404         /**
1405          * Get the list of category names this page belongs to.
1406          *
1407          * @param string $type The type of categories which should be returned. Possible values:
1408          *  * all: all categories of all types
1409          *  * hidden: only the hidden categories
1410          *  * normal: all categories, except hidden categories
1411          * @return array Array of strings
1412          */
1413         public function getCategories( $type = 'all' ) {
1414                 if ( $type === 'all' ) {
1415                         $allCategories = [];
1416                         foreach ( $this->mCategories as $categories ) {
1417                                 $allCategories = array_merge( $allCategories, $categories );
1418                         }
1419                         return $allCategories;
1420                 }
1421                 if ( !isset( $this->mCategories[$type] ) ) {
1422                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1423                 }
1424                 return $this->mCategories[$type];
1425         }
1426
1427         /**
1428          * Add an array of indicators, with their identifiers as array
1429          * keys and HTML contents as values.
1430          *
1431          * In case of duplicate keys, existing values are overwritten.
1432          *
1433          * @param array $indicators
1434          * @since 1.25
1435          */
1436         public function setIndicators( array $indicators ) {
1437                 $this->mIndicators = $indicators + $this->mIndicators;
1438                 // Keep ordered by key
1439                 ksort( $this->mIndicators );
1440         }
1441
1442         /**
1443          * Get the indicators associated with this page.
1444          *
1445          * The array will be internally ordered by item keys.
1446          *
1447          * @return array Keys: identifiers, values: HTML contents
1448          * @since 1.25
1449          */
1450         public function getIndicators() {
1451                 return $this->mIndicators;
1452         }
1453
1454         /**
1455          * Adds help link with an icon via page indicators.
1456          * Link target can be overridden by a local message containing a wikilink:
1457          * the message key is: lowercase action or special page name + '-helppage'.
1458          * @param string $to Target MediaWiki.org page title or encoded URL.
1459          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1460          * @since 1.25
1461          */
1462         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1463                 $this->addModuleStyles( 'mediawiki.helplink' );
1464                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1465
1466                 if ( $overrideBaseUrl ) {
1467                         $helpUrl = $to;
1468                 } else {
1469                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1470                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1471                 }
1472
1473                 $link = Html::rawElement(
1474                         'a',
1475                         [
1476                                 'href' => $helpUrl,
1477                                 'target' => '_blank',
1478                                 'class' => 'mw-helplink',
1479                         ],
1480                         $text
1481                 );
1482
1483                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1484         }
1485
1486         /**
1487          * Do not allow scripts which can be modified by wiki users to load on this page;
1488          * only allow scripts bundled with, or generated by, the software.
1489          * Site-wide styles are controlled by a config setting, since they can be
1490          * used to create a custom skin/theme, but not user-specific ones.
1491          *
1492          * @todo this should be given a more accurate name
1493          */
1494         public function disallowUserJs() {
1495                 $this->reduceAllowedModules(
1496                         ResourceLoaderModule::TYPE_SCRIPTS,
1497                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1498                 );
1499
1500                 // Site-wide styles are controlled by a config setting, see T73621
1501                 // for background on why. User styles are never allowed.
1502                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1503                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1504                 } else {
1505                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1506                 }
1507                 $this->reduceAllowedModules(
1508                         ResourceLoaderModule::TYPE_STYLES,
1509                         $styleOrigin
1510                 );
1511         }
1512
1513         /**
1514          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1515          * @see ResourceLoaderModule::$origin
1516          * @param string $type ResourceLoaderModule TYPE_ constant
1517          * @return int ResourceLoaderModule ORIGIN_ class constant
1518          */
1519         public function getAllowedModules( $type ) {
1520                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1521                         return min( array_values( $this->mAllowedModules ) );
1522                 } else {
1523                         return isset( $this->mAllowedModules[$type] )
1524                                 ? $this->mAllowedModules[$type]
1525                                 : ResourceLoaderModule::ORIGIN_ALL;
1526                 }
1527         }
1528
1529         /**
1530          * Limit the highest level of CSS/JS untrustworthiness allowed.
1531          *
1532          * If passed the same or a higher level than the current level of untrustworthiness set, the
1533          * level will remain unchanged.
1534          *
1535          * @param string $type
1536          * @param int $level ResourceLoaderModule class constant
1537          */
1538         public function reduceAllowedModules( $type, $level ) {
1539                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1540         }
1541
1542         /**
1543          * Prepend $text to the body HTML
1544          *
1545          * @param string $text HTML
1546          */
1547         public function prependHTML( $text ) {
1548                 $this->mBodytext = $text . $this->mBodytext;
1549         }
1550
1551         /**
1552          * Append $text to the body HTML
1553          *
1554          * @param string $text HTML
1555          */
1556         public function addHTML( $text ) {
1557                 $this->mBodytext .= $text;
1558         }
1559
1560         /**
1561          * Shortcut for adding an Html::element via addHTML.
1562          *
1563          * @since 1.19
1564          *
1565          * @param string $element
1566          * @param array $attribs
1567          * @param string $contents
1568          */
1569         public function addElement( $element, array $attribs = [], $contents = '' ) {
1570                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1571         }
1572
1573         /**
1574          * Clear the body HTML
1575          */
1576         public function clearHTML() {
1577                 $this->mBodytext = '';
1578         }
1579
1580         /**
1581          * Get the body HTML
1582          *
1583          * @return string HTML
1584          */
1585         public function getHTML() {
1586                 return $this->mBodytext;
1587         }
1588
1589         /**
1590          * Get/set the ParserOptions object to use for wikitext parsing
1591          *
1592          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1593          *   current ParserOption object. This parameter is deprecated since 1.31.
1594          * @return ParserOptions
1595          */
1596         public function parserOptions( $options = null ) {
1597                 if ( $options !== null ) {
1598                         wfDeprecated( __METHOD__ . ' with non-null $options', '1.31' );
1599                 }
1600
1601                 if ( $options !== null && !empty( $options->isBogus ) ) {
1602                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1603                         // been changed somehow, and keep it if so.
1604                         $anonPO = ParserOptions::newFromAnon();
1605                         $anonPO->setAllowUnsafeRawHtml( false );
1606                         if ( !$options->matches( $anonPO ) ) {
1607                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1608                                 $options->isBogus = false;
1609                         }
1610                 }
1611
1612                 if ( !$this->mParserOptions ) {
1613                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1614                                 // $wgUser isn't unstubbable yet, so don't try to get a
1615                                 // ParserOptions for it. And don't cache this ParserOptions
1616                                 // either.
1617                                 $po = ParserOptions::newFromAnon();
1618                                 $po->setAllowUnsafeRawHtml( false );
1619                                 $po->isBogus = true;
1620                                 if ( $options !== null ) {
1621                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1622                                 }
1623                                 return $po;
1624                         }
1625
1626                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1627                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1628                 }
1629
1630                 if ( $options !== null && !empty( $options->isBogus ) ) {
1631                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1632                         // thing.
1633                         return wfSetVar( $this->mParserOptions, null, true );
1634                 } else {
1635                         return wfSetVar( $this->mParserOptions, $options );
1636                 }
1637         }
1638
1639         /**
1640          * Set the revision ID which will be seen by the wiki text parser
1641          * for things such as embedded {{REVISIONID}} variable use.
1642          *
1643          * @param int|null $revid An positive integer, or null
1644          * @return mixed Previous value
1645          */
1646         public function setRevisionId( $revid ) {
1647                 $val = is_null( $revid ) ? null : intval( $revid );
1648                 return wfSetVar( $this->mRevisionId, $val );
1649         }
1650
1651         /**
1652          * Get the displayed revision ID
1653          *
1654          * @return int
1655          */
1656         public function getRevisionId() {
1657                 return $this->mRevisionId;
1658         }
1659
1660         /**
1661          * Set the timestamp of the revision which will be displayed. This is used
1662          * to avoid a extra DB call in Skin::lastModified().
1663          *
1664          * @param string|null $timestamp
1665          * @return mixed Previous value
1666          */
1667         public function setRevisionTimestamp( $timestamp ) {
1668                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1669         }
1670
1671         /**
1672          * Get the timestamp of displayed revision.
1673          * This will be null if not filled by setRevisionTimestamp().
1674          *
1675          * @return string|null
1676          */
1677         public function getRevisionTimestamp() {
1678                 return $this->mRevisionTimestamp;
1679         }
1680
1681         /**
1682          * Set the displayed file version
1683          *
1684          * @param File|bool $file
1685          * @return mixed Previous value
1686          */
1687         public function setFileVersion( $file ) {
1688                 $val = null;
1689                 if ( $file instanceof File && $file->exists() ) {
1690                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1691                 }
1692                 return wfSetVar( $this->mFileVersion, $val, true );
1693         }
1694
1695         /**
1696          * Get the displayed file version
1697          *
1698          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1699          */
1700         public function getFileVersion() {
1701                 return $this->mFileVersion;
1702         }
1703
1704         /**
1705          * Get the templates used on this page
1706          *
1707          * @return array (namespace => dbKey => revId)
1708          * @since 1.18
1709          */
1710         public function getTemplateIds() {
1711                 return $this->mTemplateIds;
1712         }
1713
1714         /**
1715          * Get the files used on this page
1716          *
1717          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1718          * @since 1.18
1719          */
1720         public function getFileSearchOptions() {
1721                 return $this->mImageTimeKeys;
1722         }
1723
1724         /**
1725          * Convert wikitext to HTML and add it to the buffer
1726          * Default assumes that the current page title will be used.
1727          *
1728          * @param string $text
1729          * @param bool $linestart Is this the start of a line?
1730          * @param bool $interface Is this text in the user interface language?
1731          * @throws MWException
1732          */
1733         public function addWikiText( $text, $linestart = true, $interface = true ) {
1734                 $title = $this->getTitle(); // Work around E_STRICT
1735                 if ( !$title ) {
1736                         throw new MWException( 'Title is null' );
1737                 }
1738                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1739         }
1740
1741         /**
1742          * Add wikitext with a custom Title object
1743          *
1744          * @param string $text Wikitext
1745          * @param Title &$title
1746          * @param bool $linestart Is this the start of a line?
1747          */
1748         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1749                 $this->addWikiTextTitle( $text, $title, $linestart );
1750         }
1751
1752         /**
1753          * Add wikitext with a custom Title object and tidy enabled.
1754          *
1755          * @param string $text Wikitext
1756          * @param Title &$title
1757          * @param bool $linestart Is this the start of a line?
1758          */
1759         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1760                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1761         }
1762
1763         /**
1764          * Add wikitext with tidy enabled
1765          *
1766          * @param string $text Wikitext
1767          * @param bool $linestart Is this the start of a line?
1768          */
1769         public function addWikiTextTidy( $text, $linestart = true ) {
1770                 $title = $this->getTitle();
1771                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1772         }
1773
1774         /**
1775          * Add wikitext with a custom Title object
1776          *
1777          * @param string $text Wikitext
1778          * @param Title $title
1779          * @param bool $linestart Is this the start of a line?
1780          * @param bool $tidy Whether to use tidy
1781          * @param bool $interface Whether it is an interface message
1782          *   (for example disables conversion)
1783          */
1784         public function addWikiTextTitle( $text, Title $title, $linestart,
1785                 $tidy = false, $interface = false
1786         ) {
1787                 global $wgParser;
1788
1789                 $popts = $this->parserOptions();
1790                 $oldTidy = $popts->setTidy( $tidy );
1791                 $popts->setInterfaceMessage( (bool)$interface );
1792
1793                 $parserOutput = $wgParser->getFreshParser()->parse(
1794                         $text, $title, $popts,
1795                         $linestart, true, $this->mRevisionId
1796                 );
1797
1798                 $popts->setTidy( $oldTidy );
1799
1800                 $this->addParserOutput( $parserOutput, [
1801                         'enableSectionEditLinks' => false,
1802                 ] );
1803         }
1804
1805         /**
1806          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1807          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1808          * and so on.
1809          *
1810          * @since 1.24
1811          * @param ParserOutput $parserOutput
1812          */
1813         public function addParserOutputMetadata( $parserOutput ) {
1814                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1815                 $this->addCategoryLinks( $parserOutput->getCategories() );
1816                 $this->setIndicators( $parserOutput->getIndicators() );
1817                 $this->mNewSectionLink = $parserOutput->getNewSection();
1818                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1819
1820                 if ( !$parserOutput->isCacheable() ) {
1821                         $this->enableClientCache( false );
1822                 }
1823                 $this->mNoGallery = $parserOutput->getNoGallery();
1824                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1825                 $this->addModules( $parserOutput->getModules() );
1826                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1827                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1828                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1829                 $this->mPreventClickjacking = $this->mPreventClickjacking
1830                         || $parserOutput->preventClickjacking();
1831
1832                 // Template versioning...
1833                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1834                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1835                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1836                         } else {
1837                                 $this->mTemplateIds[$ns] = $dbks;
1838                         }
1839                 }
1840                 // File versioning...
1841                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1842                         $this->mImageTimeKeys[$dbk] = $data;
1843                 }
1844
1845                 // Hooks registered in the object
1846                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1847                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1848                         list( $hookName, $data ) = $hookInfo;
1849                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1850                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1851                         }
1852                 }
1853
1854                 // Enable OOUI if requested via ParserOutput
1855                 if ( $parserOutput->getEnableOOUI() ) {
1856                         $this->enableOOUI();
1857                 }
1858
1859                 // Include parser limit report
1860                 if ( !$this->limitReportJSData ) {
1861                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1862                 }
1863
1864                 // Link flags are ignored for now, but may in the future be
1865                 // used to mark individual language links.
1866                 $linkFlags = [];
1867                 // Avoid PHP 7.1 warning of passing $this by reference
1868                 $outputPage = $this;
1869                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1870                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1871
1872                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
1873                 // so that extensions may modify ParserOutput to toggle TOC.
1874                 // This cannot be moved to addParserOutputText because that is not
1875                 // called by EditPage for Preview.
1876                 if ( $parserOutput->getTOCHTML() ) {
1877                         $this->mEnableTOC = true;
1878                 }
1879         }
1880
1881         /**
1882          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1883          * ParserOutput object, without any other metadata.
1884          *
1885          * @since 1.24
1886          * @param ParserOutput $parserOutput
1887          * @param array $poOptions Options to ParserOutput::getText()
1888          */
1889         public function addParserOutputContent( $parserOutput, $poOptions = [] ) {
1890                 $this->addParserOutputText( $parserOutput, $poOptions );
1891
1892                 $this->addModules( $parserOutput->getModules() );
1893                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1894                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1895
1896                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1897         }
1898
1899         /**
1900          * Add the HTML associated with a ParserOutput object, without any metadata.
1901          *
1902          * @since 1.24
1903          * @param ParserOutput $parserOutput
1904          * @param array $poOptions Options to ParserOutput::getText()
1905          */
1906         public function addParserOutputText( $parserOutput, $poOptions = [] ) {
1907                 $text = $parserOutput->getText( $poOptions );
1908                 // Avoid PHP 7.1 warning of passing $this by reference
1909                 $outputPage = $this;
1910                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1911                 $this->addHTML( $text );
1912         }
1913
1914         /**
1915          * Add everything from a ParserOutput object.
1916          *
1917          * @param ParserOutput $parserOutput
1918          * @param array $poOptions Options to ParserOutput::getText()
1919          */
1920         function addParserOutput( $parserOutput, $poOptions = [] ) {
1921                 $this->addParserOutputMetadata( $parserOutput );
1922                 $this->addParserOutputText( $parserOutput, $poOptions );
1923         }
1924
1925         /**
1926          * Add the output of a QuickTemplate to the output buffer
1927          *
1928          * @param QuickTemplate &$template
1929          */
1930         public function addTemplate( &$template ) {
1931                 $this->addHTML( $template->getHTML() );
1932         }
1933
1934         /**
1935          * Parse wikitext and return the HTML.
1936          *
1937          * @param string $text
1938          * @param bool $linestart Is this the start of a line?
1939          * @param bool $interface Use interface language ($wgLang instead of
1940          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1941          *   This also disables LanguageConverter.
1942          * @param Language $language Target language object, will override $interface
1943          * @throws MWException
1944          * @return string HTML
1945          */
1946         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1947                 global $wgParser;
1948
1949                 if ( is_null( $this->getTitle() ) ) {
1950                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1951                 }
1952
1953                 $popts = $this->parserOptions();
1954                 if ( $interface ) {
1955                         $popts->setInterfaceMessage( true );
1956                 }
1957                 if ( $language !== null ) {
1958                         $oldLang = $popts->setTargetLanguage( $language );
1959                 }
1960
1961                 $parserOutput = $wgParser->getFreshParser()->parse(
1962                         $text, $this->getTitle(), $popts,
1963                         $linestart, true, $this->mRevisionId
1964                 );
1965
1966                 if ( $interface ) {
1967                         $popts->setInterfaceMessage( false );
1968                 }
1969                 if ( $language !== null ) {
1970                         $popts->setTargetLanguage( $oldLang );
1971                 }
1972
1973                 return $parserOutput->getText( [
1974                         'enableSectionEditLinks' => false,
1975                 ] );
1976         }
1977
1978         /**
1979          * Parse wikitext, strip paragraphs, and return the HTML.
1980          *
1981          * @param string $text
1982          * @param bool $linestart Is this the start of a line?
1983          * @param bool $interface Use interface language ($wgLang instead of
1984          *   $wgContLang) while parsing language sensitive magic
1985          *   words like GRAMMAR and PLURAL
1986          * @return string HTML
1987          */
1988         public function parseInline( $text, $linestart = true, $interface = false ) {
1989                 $parsed = $this->parse( $text, $linestart, $interface );
1990                 return Parser::stripOuterParagraph( $parsed );
1991         }
1992
1993         /**
1994          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1995          *
1996          * @param int $maxage Maximum cache time on the CDN, in seconds.
1997          */
1998         public function setCdnMaxage( $maxage ) {
1999                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
2000         }
2001
2002         /**
2003          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
2004          *
2005          * @param int $maxage Maximum cache time on the CDN, in seconds
2006          * @since 1.27
2007          */
2008         public function lowerCdnMaxage( $maxage ) {
2009                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
2010                 $this->setCdnMaxage( $this->mCdnMaxage );
2011         }
2012
2013         /**
2014          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
2015          *
2016          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
2017          * the TTL is higher the older the $mtime timestamp is. Essentially, the
2018          * TTL is 90% of the age of the object, subject to the min and max.
2019          *
2020          * @param string|int|float|bool|null $mtime Last-Modified timestamp
2021          * @param int $minTTL Mimimum TTL in seconds [default: 1 minute]
2022          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
2023          * @return int TTL in seconds
2024          * @since 1.28
2025          */
2026         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
2027                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
2028                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
2029
2030                 if ( $mtime === null || $mtime === false ) {
2031                         return $minTTL; // entity does not exist
2032                 }
2033
2034                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
2035                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
2036                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
2037
2038                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2039
2040                 return $adaptiveTTL;
2041         }
2042
2043         /**
2044          * Use enableClientCache(false) to force it to send nocache headers
2045          *
2046          * @param bool $state
2047          *
2048          * @return bool
2049          */
2050         public function enableClientCache( $state ) {
2051                 return wfSetVar( $this->mEnableClientCache, $state );
2052         }
2053
2054         /**
2055          * Get the list of cookies that will influence on the cache
2056          *
2057          * @return array
2058          */
2059         function getCacheVaryCookies() {
2060                 static $cookies;
2061                 if ( $cookies === null ) {
2062                         $config = $this->getConfig();
2063                         $cookies = array_merge(
2064                                 SessionManager::singleton()->getVaryCookies(),
2065                                 [
2066                                         'forceHTTPS',
2067                                 ],
2068                                 $config->get( 'CacheVaryCookies' )
2069                         );
2070                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2071                 }
2072                 return $cookies;
2073         }
2074
2075         /**
2076          * Check if the request has a cache-varying cookie header
2077          * If it does, it's very important that we don't allow public caching
2078          *
2079          * @return bool
2080          */
2081         function haveCacheVaryCookies() {
2082                 $request = $this->getRequest();
2083                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2084                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2085                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2086                                 return true;
2087                         }
2088                 }
2089                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2090                 return false;
2091         }
2092
2093         /**
2094          * Add an HTTP header that will influence on the cache
2095          *
2096          * @param string $header Header name
2097          * @param string[]|null $option Options for the Key header. See
2098          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2099          * for the list of valid options.
2100          */
2101         public function addVaryHeader( $header, array $option = null ) {
2102                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2103                         $this->mVaryHeader[$header] = [];
2104                 }
2105                 if ( !is_array( $option ) ) {
2106                         $option = [];
2107                 }
2108                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2109         }
2110
2111         /**
2112          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2113          * such as Accept-Encoding or Cookie
2114          *
2115          * @return string
2116          */
2117         public function getVaryHeader() {
2118                 // If we vary on cookies, let's make sure it's always included here too.
2119                 if ( $this->getCacheVaryCookies() ) {
2120                         $this->addVaryHeader( 'Cookie' );
2121                 }
2122
2123                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2124                         $this->addVaryHeader( $header, $options );
2125                 }
2126                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2127         }
2128
2129         /**
2130          * Add an HTTP Link: header
2131          *
2132          * @param string $header Header value
2133          */
2134         public function addLinkHeader( $header ) {
2135                 $this->mLinkHeader[] = $header;
2136         }
2137
2138         /**
2139          * Return a Link: header. Based on the values of $mLinkHeader.
2140          *
2141          * @return string
2142          */
2143         public function getLinkHeader() {
2144                 if ( !$this->mLinkHeader ) {
2145                         return false;
2146                 }
2147
2148                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2149         }
2150
2151         /**
2152          * Get a complete Key header
2153          *
2154          * @return string
2155          */
2156         public function getKeyHeader() {
2157                 $cvCookies = $this->getCacheVaryCookies();
2158
2159                 $cookiesOption = [];
2160                 foreach ( $cvCookies as $cookieName ) {
2161                         $cookiesOption[] = 'param=' . $cookieName;
2162                 }
2163                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2164
2165                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2166                         $this->addVaryHeader( $header, $options );
2167                 }
2168
2169                 $headers = [];
2170                 foreach ( $this->mVaryHeader as $header => $option ) {
2171                         $newheader = $header;
2172                         if ( is_array( $option ) && count( $option ) > 0 ) {
2173                                 $newheader .= ';' . implode( ';', $option );
2174                         }
2175                         $headers[] = $newheader;
2176                 }
2177                 $key = 'Key: ' . implode( ',', $headers );
2178
2179                 return $key;
2180         }
2181
2182         /**
2183          * T23672: Add Accept-Language to Vary and Key headers
2184          * if there's no 'variant' parameter existed in GET.
2185          *
2186          * For example:
2187          *   /w/index.php?title=Main_page should always be served; but
2188          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2189          */
2190         function addAcceptLanguage() {
2191                 $title = $this->getTitle();
2192                 if ( !$title instanceof Title ) {
2193                         return;
2194                 }
2195
2196                 $lang = $title->getPageLanguage();
2197                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2198                         $variants = $lang->getVariants();
2199                         $aloption = [];
2200                         foreach ( $variants as $variant ) {
2201                                 if ( $variant === $lang->getCode() ) {
2202                                         continue;
2203                                 } else {
2204                                         $aloption[] = 'substr=' . $variant;
2205
2206                                         // IE and some other browsers use BCP 47 standards in
2207                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2208                                         // We should handle these too.
2209                                         $variantBCP47 = LanguageCode::bcp47( $variant );
2210                                         if ( $variantBCP47 !== $variant ) {
2211                                                 $aloption[] = 'substr=' . $variantBCP47;
2212                                         }
2213                                 }
2214                         }
2215                         $this->addVaryHeader( 'Accept-Language', $aloption );
2216                 }
2217         }
2218
2219         /**
2220          * Set a flag which will cause an X-Frame-Options header appropriate for
2221          * edit pages to be sent. The header value is controlled by
2222          * $wgEditPageFrameOptions.
2223          *
2224          * This is the default for special pages. If you display a CSRF-protected
2225          * form on an ordinary view page, then you need to call this function.
2226          *
2227          * @param bool $enable
2228          */
2229         public function preventClickjacking( $enable = true ) {
2230                 $this->mPreventClickjacking = $enable;
2231         }
2232
2233         /**
2234          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2235          * This can be called from pages which do not contain any CSRF-protected
2236          * HTML form.
2237          */
2238         public function allowClickjacking() {
2239                 $this->mPreventClickjacking = false;
2240         }
2241
2242         /**
2243          * Get the prevent-clickjacking flag
2244          *
2245          * @since 1.24
2246          * @return bool
2247          */
2248         public function getPreventClickjacking() {
2249                 return $this->mPreventClickjacking;
2250         }
2251
2252         /**
2253          * Get the X-Frame-Options header value (without the name part), or false
2254          * if there isn't one. This is used by Skin to determine whether to enable
2255          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2256          *
2257          * @return string|false
2258          */
2259         public function getFrameOptions() {
2260                 $config = $this->getConfig();
2261                 if ( $config->get( 'BreakFrames' ) ) {
2262                         return 'DENY';
2263                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2264                         return $config->get( 'EditPageFrameOptions' );
2265                 }
2266                 return false;
2267         }
2268
2269         /**
2270          * Send cache control HTTP headers
2271          */
2272         public function sendCacheControl() {
2273                 $response = $this->getRequest()->response();
2274                 $config = $this->getConfig();
2275
2276                 $this->addVaryHeader( 'Cookie' );
2277                 $this->addAcceptLanguage();
2278
2279                 # don't serve compressed data to clients who can't handle it
2280                 # maintain different caches for logged-in users and non-logged in ones
2281                 $response->header( $this->getVaryHeader() );
2282
2283                 if ( $config->get( 'UseKeyHeader' ) ) {
2284                         $response->header( $this->getKeyHeader() );
2285                 }
2286
2287                 if ( $this->mEnableClientCache ) {
2288                         if (
2289                                 $config->get( 'UseSquid' ) &&
2290                                 !$response->hasCookies() &&
2291                                 !SessionManager::getGlobalSession()->isPersistent() &&
2292                                 !$this->isPrintable() &&
2293                                 $this->mCdnMaxage != 0 &&
2294                                 !$this->haveCacheVaryCookies()
2295                         ) {
2296                                 if ( $config->get( 'UseESI' ) ) {
2297                                         # We'll purge the proxy cache explicitly, but require end user agents
2298                                         # to revalidate against the proxy on each visit.
2299                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2300                                         wfDebug( __METHOD__ .
2301                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2302                                         # start with a shorter timeout for initial testing
2303                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2304                                         $response->header(
2305                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2306                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2307                                         );
2308                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2309                                 } else {
2310                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2311                                         # to revalidate against the proxy on each visit.
2312                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2313                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2314                                         wfDebug( __METHOD__ .
2315                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2316                                         # start with a shorter timeout for initial testing
2317                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2318                                         $response->header( "Cache-Control: " .
2319                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2320                                 }
2321                         } else {
2322                                 # We do want clients to cache if they can, but they *must* check for updates
2323                                 # on revisiting the page.
2324                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2325                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2326                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2327                         }
2328                         if ( $this->mLastModified ) {
2329                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2330                         }
2331                 } else {
2332                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2333
2334                         # In general, the absence of a last modified header should be enough to prevent
2335                         # the client from using its cache. We send a few other things just to make sure.
2336                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2337                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2338                         $response->header( 'Pragma: no-cache' );
2339                 }
2340         }
2341
2342         /**
2343          * Transfer styles and JavaScript modules from skin.
2344          *
2345          * @param Skin $sk to load modules for
2346          */
2347         public function loadSkinModules( $sk ) {
2348                 foreach ( $sk->getDefaultModules() as $group => $modules ) {
2349                         if ( $group === 'styles' ) {
2350                                 foreach ( $modules as $key => $moduleMembers ) {
2351                                         $this->addModuleStyles( $moduleMembers );
2352                                 }
2353                         } else {
2354                                 $this->addModules( $modules );
2355                         }
2356                 }
2357         }
2358
2359         /**
2360          * Finally, all the text has been munged and accumulated into
2361          * the object, let's actually output it:
2362          *
2363          * @param bool $return Set to true to get the result as a string rather than sending it
2364          * @return string|null
2365          * @throws Exception
2366          * @throws FatalError
2367          * @throws MWException
2368          */
2369         public function output( $return = false ) {
2370                 global $wgContLang;
2371
2372                 if ( $this->mDoNothing ) {
2373                         return $return ? '' : null;
2374                 }
2375
2376                 $response = $this->getRequest()->response();
2377                 $config = $this->getConfig();
2378
2379                 if ( $this->mRedirect != '' ) {
2380                         # Standards require redirect URLs to be absolute
2381                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2382
2383                         $redirect = $this->mRedirect;
2384                         $code = $this->mRedirectCode;
2385
2386                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2387                                 if ( $code == '301' || $code == '303' ) {
2388                                         if ( !$config->get( 'DebugRedirects' ) ) {
2389                                                 $response->statusHeader( $code );
2390                                         }
2391                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2392                                 }
2393                                 if ( $config->get( 'VaryOnXFP' ) ) {
2394                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2395                                 }
2396                                 $this->sendCacheControl();
2397
2398                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2399                                 if ( $config->get( 'DebugRedirects' ) ) {
2400                                         $url = htmlspecialchars( $redirect );
2401                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2402                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2403                                         print "</body>\n</html>\n";
2404                                 } else {
2405                                         $response->header( 'Location: ' . $redirect );
2406                                 }
2407                         }
2408
2409                         return $return ? '' : null;
2410                 } elseif ( $this->mStatusCode ) {
2411                         $response->statusHeader( $this->mStatusCode );
2412                 }
2413
2414                 # Buffer output; final headers may depend on later processing
2415                 ob_start();
2416
2417                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2418                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2419
2420                 if ( !$this->mArticleBodyOnly ) {
2421                         $sk = $this->getSkin();
2422
2423                         if ( $sk->shouldPreloadLogo() ) {
2424                                 $this->addLogoPreloadLinkHeaders();
2425                         }
2426                 }
2427
2428                 $linkHeader = $this->getLinkHeader();
2429                 if ( $linkHeader ) {
2430                         $response->header( $linkHeader );
2431                 }
2432
2433                 // Prevent framing, if requested
2434                 $frameOptions = $this->getFrameOptions();
2435                 if ( $frameOptions ) {
2436                         $response->header( "X-Frame-Options: $frameOptions" );
2437                 }
2438
2439                 ContentSecurityPolicy::sendHeaders( $this );
2440
2441                 if ( $this->mArticleBodyOnly ) {
2442                         echo $this->mBodytext;
2443                 } else {
2444                         // Enable safe mode if requested (T152169)
2445                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2446                                 $this->disallowUserJs();
2447                         }
2448
2449                         $sk = $this->getSkin();
2450                         $this->loadSkinModules( $sk );
2451
2452                         MWDebug::addModules( $this );
2453
2454                         // Avoid PHP 7.1 warning of passing $this by reference
2455                         $outputPage = $this;
2456                         // Hook that allows last minute changes to the output page, e.g.
2457                         // adding of CSS or Javascript by extensions.
2458                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2459
2460                         try {
2461                                 $sk->outputPage();
2462                         } catch ( Exception $e ) {
2463                                 ob_end_clean(); // bug T129657
2464                                 throw $e;
2465                         }
2466                 }
2467
2468                 try {
2469                         // This hook allows last minute changes to final overall output by modifying output buffer
2470                         Hooks::runWithoutAbort( 'AfterFinalPageOutput', [ $this ] );
2471                 } catch ( Exception $e ) {
2472                         ob_end_clean(); // bug T129657
2473                         throw $e;
2474                 }
2475
2476                 $this->sendCacheControl();
2477
2478                 if ( $return ) {
2479                         return ob_get_clean();
2480                 } else {
2481                         ob_end_flush();
2482                         return null;
2483                 }
2484         }
2485
2486         /**
2487          * Prepare this object to display an error page; disable caching and
2488          * indexing, clear the current text and redirect, set the page's title
2489          * and optionally an custom HTML title (content of the "<title>" tag).
2490          *
2491          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2492          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2493          *                   optional, if not passed the "<title>" attribute will be
2494          *                   based on $pageTitle
2495          */
2496         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2497                 $this->setPageTitle( $pageTitle );
2498                 if ( $htmlTitle !== false ) {
2499                         $this->setHTMLTitle( $htmlTitle );
2500                 }
2501                 $this->setRobotPolicy( 'noindex,nofollow' );
2502                 $this->setArticleRelated( false );
2503                 $this->enableClientCache( false );
2504                 $this->mRedirect = '';
2505                 $this->clearSubtitle();
2506                 $this->clearHTML();
2507         }
2508
2509         /**
2510          * Output a standard error page
2511          *
2512          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2513          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2514          * showErrorPage( 'titlemsg', $messageObject );
2515          * showErrorPage( $titleMessageObject, $messageObject );
2516          *
2517          * @param string|Message $title Message key (string) for page title, or a Message object
2518          * @param string|Message $msg Message key (string) for page text, or a Message object
2519          * @param array $params Message parameters; ignored if $msg is a Message object
2520          */
2521         public function showErrorPage( $title, $msg, $params = [] ) {
2522                 if ( !$title instanceof Message ) {
2523                         $title = $this->msg( $title );
2524                 }
2525
2526                 $this->prepareErrorPage( $title );
2527
2528                 if ( $msg instanceof Message ) {
2529                         if ( $params !== [] ) {
2530                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2531                                         . 'is discarded when the $msg argument is a Message object instead of '
2532                                         . 'a string.', E_USER_NOTICE );
2533                         }
2534                         $this->addHTML( $msg->parseAsBlock() );
2535                 } else {
2536                         $this->addWikiMsgArray( $msg, $params );
2537                 }
2538
2539                 $this->returnToMain();
2540         }
2541
2542         /**
2543          * Output a standard permission error page
2544          *
2545          * @param array $errors Error message keys or [key, param...] arrays
2546          * @param string $action Action that was denied or null if unknown
2547          */
2548         public function showPermissionsErrorPage( array $errors, $action = null ) {
2549                 foreach ( $errors as $key => $error ) {
2550                         $errors[$key] = (array)$error;
2551                 }
2552
2553                 // For some action (read, edit, create and upload), display a "login to do this action"
2554                 // error if all of the following conditions are met:
2555                 // 1. the user is not logged in
2556                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2557                 // 3. the error can be avoided simply by logging in
2558                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2559                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2560                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2561                         && ( User::groupHasPermission( 'user', $action )
2562                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2563                 ) {
2564                         $displayReturnto = null;
2565
2566                         # Due to T34276, if a user does not have read permissions,
2567                         # $this->getTitle() will just give Special:Badtitle, which is
2568                         # not especially useful as a returnto parameter. Use the title
2569                         # from the request instead, if there was one.
2570                         $request = $this->getRequest();
2571                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2572                         if ( $action == 'edit' ) {
2573                                 $msg = 'whitelistedittext';
2574                                 $displayReturnto = $returnto;
2575                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2576                                 $msg = 'nocreatetext';
2577                         } elseif ( $action == 'upload' ) {
2578                                 $msg = 'uploadnologintext';
2579                         } else { # Read
2580                                 $msg = 'loginreqpagetext';
2581                                 $displayReturnto = Title::newMainPage();
2582                         }
2583
2584                         $query = [];
2585
2586                         if ( $returnto ) {
2587                                 $query['returnto'] = $returnto->getPrefixedText();
2588
2589                                 if ( !$request->wasPosted() ) {
2590                                         $returntoquery = $request->getValues();
2591                                         unset( $returntoquery['title'] );
2592                                         unset( $returntoquery['returnto'] );
2593                                         unset( $returntoquery['returntoquery'] );
2594                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2595                                 }
2596                         }
2597                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2598                         $loginLink = $linkRenderer->makeKnownLink(
2599                                 SpecialPage::getTitleFor( 'Userlogin' ),
2600                                 $this->msg( 'loginreqlink' )->text(),
2601                                 [],
2602                                 $query
2603                         );
2604
2605                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2606                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2607
2608                         # Don't return to a page the user can't read otherwise
2609                         # we'll end up in a pointless loop
2610                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2611                                 $this->returnToMain( null, $displayReturnto );
2612                         }
2613                 } else {
2614                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2615                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2616                 }
2617         }
2618
2619         /**
2620          * Display an error page indicating that a given version of MediaWiki is
2621          * required to use it
2622          *
2623          * @param mixed $version The version of MediaWiki needed to use the page
2624          */
2625         public function versionRequired( $version ) {
2626                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2627
2628                 $this->addWikiMsg( 'versionrequiredtext', $version );
2629                 $this->returnToMain();
2630         }
2631
2632         /**
2633          * Format a list of error messages
2634          *
2635          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2636          * @param string $action Action that was denied or null if unknown
2637          * @return string The wikitext error-messages, formatted into a list.
2638          */
2639         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2640                 if ( $action == null ) {
2641                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2642                 } else {
2643                         $action_desc = $this->msg( "action-$action" )->plain();
2644                         $text = $this->msg(
2645                                 'permissionserrorstext-withaction',
2646                                 count( $errors ),
2647                                 $action_desc
2648                         )->plain() . "\n\n";
2649                 }
2650
2651                 if ( count( $errors ) > 1 ) {
2652                         $text .= '<ul class="permissions-errors">' . "\n";
2653
2654                         foreach ( $errors as $error ) {
2655                                 $text .= '<li>';
2656                                 $text .= call_user_func_array( [ $this, 'msg' ], $error )->plain();
2657                                 $text .= "</li>\n";
2658                         }
2659                         $text .= '</ul>';
2660                 } else {
2661                         $text .= "<div class=\"permissions-errors\">\n" .
2662                                         call_user_func_array( [ $this, 'msg' ], reset( $errors ) )->plain() .
2663                                         "\n</div>";
2664                 }
2665
2666                 return $text;
2667         }
2668
2669         /**
2670          * Show a warning about replica DB lag
2671          *
2672          * If the lag is higher than $wgSlaveLagCritical seconds,
2673          * then the warning is a bit more obvious. If the lag is
2674          * lower than $wgSlaveLagWarning, then no warning is shown.
2675          *
2676          * @param int $lag Slave lag
2677          */
2678         public function showLagWarning( $lag ) {
2679                 $config = $this->getConfig();
2680                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2681                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2682                         $message = $lag < $config->get( 'SlaveLagCritical' )
2683                                 ? 'lag-warn-normal'
2684                                 : 'lag-warn-high';
2685                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2686                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2687                 }
2688         }
2689
2690         public function showFatalError( $message ) {
2691                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2692
2693                 $this->addHTML( $message );
2694         }
2695
2696         public function showUnexpectedValueError( $name, $val ) {
2697                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2698         }
2699
2700         public function showFileCopyError( $old, $new ) {
2701                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2702         }
2703
2704         public function showFileRenameError( $old, $new ) {
2705                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2706         }
2707
2708         public function showFileDeleteError( $name ) {
2709                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2710         }
2711
2712         public function showFileNotFoundError( $name ) {
2713                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2714         }
2715
2716         /**
2717          * Add a "return to" link pointing to a specified title
2718          *
2719          * @param Title $title Title to link
2720          * @param array $query Query string parameters
2721          * @param string $text Text of the link (input is not escaped)
2722          * @param array $options Options array to pass to Linker
2723          */
2724         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2725                 $linkRenderer = MediaWikiServices::getInstance()
2726                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
2727                 $link = $this->msg( 'returnto' )->rawParams(
2728                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
2729                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2730         }
2731
2732         /**
2733          * Add a "return to" link pointing to a specified title,
2734          * or the title indicated in the request, or else the main page
2735          *
2736          * @param mixed $unused
2737          * @param Title|string $returnto Title or String to return to
2738          * @param string $returntoquery Query string for the return to link
2739          */
2740         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2741                 if ( $returnto == null ) {
2742                         $returnto = $this->getRequest()->getText( 'returnto' );
2743                 }
2744
2745                 if ( $returntoquery == null ) {
2746                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2747                 }
2748
2749                 if ( $returnto === '' ) {
2750                         $returnto = Title::newMainPage();
2751                 }
2752
2753                 if ( is_object( $returnto ) ) {
2754                         $titleObj = $returnto;
2755                 } else {
2756                         $titleObj = Title::newFromText( $returnto );
2757                 }
2758                 // We don't want people to return to external interwiki. That
2759                 // might potentially be used as part of a phishing scheme
2760                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
2761                         $titleObj = Title::newMainPage();
2762                 }
2763
2764                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2765         }
2766
2767         private function getRlClientContext() {
2768                 if ( !$this->rlClientContext ) {
2769                         $query = ResourceLoader::makeLoaderQuery(
2770                                 [], // modules; not relevant
2771                                 $this->getLanguage()->getCode(),
2772                                 $this->getSkin()->getSkinName(),
2773                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2774                                 null, // version; not relevant
2775                                 ResourceLoader::inDebugMode(),
2776                                 null, // only; not relevant
2777                                 $this->isPrintable(),
2778                                 $this->getRequest()->getBool( 'handheld' )
2779                         );
2780                         $this->rlClientContext = new ResourceLoaderContext(
2781                                 $this->getResourceLoader(),
2782                                 new FauxRequest( $query )
2783                         );
2784                         if ( $this->contentOverrideCallbacks ) {
2785                                 $this->rlClientContext = new DerivativeResourceLoaderContext( $this->rlClientContext );
2786                                 $this->rlClientContext->setContentOverrideCallback( function ( Title $title ) {
2787                                         foreach ( $this->contentOverrideCallbacks as $callback ) {
2788                                                 $content = call_user_func( $callback, $title );
2789                                                 if ( $content !== null ) {
2790                                                         return $content;
2791                                                 }
2792                                         }
2793                                         return null;
2794                                 } );
2795                         }
2796                 }
2797                 return $this->rlClientContext;
2798         }
2799
2800         /**
2801          * Call this to freeze the module queue and JS config and create a formatter.
2802          *
2803          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2804          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2805          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2806          * the module filters retroactively. Skins and extension hooks may also add modules until very
2807          * late in the request lifecycle.
2808          *
2809          * @return ResourceLoaderClientHtml
2810          */
2811         public function getRlClient() {
2812                 if ( !$this->rlClient ) {
2813                         $context = $this->getRlClientContext();
2814                         $rl = $this->getResourceLoader();
2815                         $this->addModules( [
2816                                 'user',
2817                                 'user.options',
2818                                 'user.tokens',
2819                         ] );
2820                         $this->addModuleStyles( [
2821                                 'site.styles',
2822                                 'noscript',
2823                                 'user.styles',
2824                         ] );
2825                         $this->getSkin()->setupSkinUserCss( $this );
2826
2827                         // Prepare exempt modules for buildExemptModules()
2828                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2829                         $exemptStates = [];
2830                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2831
2832                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2833                         // Separate user-specific batch for improved cache-hit ratio.
2834                         $userBatch = [ 'user.styles', 'user' ];
2835                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2836                         $dbr = wfGetDB( DB_REPLICA );
2837                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2838                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2839
2840                         // Filter out modules handled by buildExemptModules()
2841                         $moduleStyles = array_filter( $moduleStyles,
2842                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2843                                         $module = $rl->getModule( $name );
2844                                         if ( $module ) {
2845                                                 $group = $module->getGroup();
2846                                                 if ( isset( $exemptGroups[$group] ) ) {
2847                                                         $exemptStates[$name] = 'ready';
2848                                                         if ( !$module->isKnownEmpty( $context ) ) {
2849                                                                 // E.g. Don't output empty <styles>
2850                                                                 $exemptGroups[$group][] = $name;
2851                                                         }
2852                                                         return false;
2853                                                 }
2854                                         }
2855                                         return true;
2856                                 }
2857                         );
2858                         $this->rlExemptStyleModules = $exemptGroups;
2859
2860                         $rlClient = new ResourceLoaderClientHtml( $context, [
2861                                 'target' => $this->getTarget(),
2862                                 'nonce' => $this->getCSPNonce(),
2863                                 // When 'safemode', disallowUserJs(), or reduceAllowedModules() is used
2864                                 // to only restrict modules to ORIGIN_CORE (ie. disallow ORIGIN_USER), the list of
2865                                 // modules enqueud for loading on this page is filtered to just those.
2866                                 // However, to make sure we also apply the restriction to dynamic dependencies and
2867                                 // lazy-loaded modules at run-time on the client-side, pass 'safemode' down to the
2868                                 // StartupModule so that the client-side registry will not contain any restricted
2869                                 // modules either. (T152169, T185303)
2870                                 'safemode' => ( $this->getAllowedModules( ResourceLoaderModule::TYPE_COMBINED )
2871                                         <= ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
2872                                 ) ? '1' : null,
2873                         ] );
2874                         $rlClient->setConfig( $this->getJSVars() );
2875                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2876                         $rlClient->setModuleStyles( $moduleStyles );
2877                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2878                         $rlClient->setExemptStates( $exemptStates );
2879                         $this->rlClient = $rlClient;
2880                 }
2881                 return $this->rlClient;
2882         }
2883
2884         /**
2885          * @param Skin $sk The given Skin
2886          * @param bool $includeStyle Unused
2887          * @return string The doctype, opening "<html>", and head element.
2888          */
2889         public function headElement( Skin $sk, $includeStyle = true ) {
2890                 global $wgContLang;
2891
2892                 $userdir = $this->getLanguage()->getDir();
2893                 $sitedir = $wgContLang->getDir();
2894
2895                 $pieces = [];
2896                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2897                         $this->getRlClient()->getDocumentAttributes(),
2898                         $sk->getHtmlElementAttributes()
2899                 ) );
2900                 $pieces[] = Html::openElement( 'head' );
2901
2902                 if ( $this->getHTMLTitle() == '' ) {
2903                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2904                 }
2905
2906                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2907                         // Add <meta charset="UTF-8">
2908                         // This should be before <title> since it defines the charset used by
2909                         // text including the text inside <title>.
2910                         // The spec recommends defining XHTML5's charset using the XML declaration
2911                         // instead of meta.
2912                         // Our XML declaration is output by Html::htmlHeader.
2913                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2914                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2915                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2916                 }
2917
2918                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2919                 $pieces[] = $this->getRlClient()->getHeadHtml();
2920                 $pieces[] = $this->buildExemptModules();
2921                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2922                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2923
2924                 // Use an IE conditional comment to serve the script only to old IE
2925                 $pieces[] = '<!--[if lt IE 9]>' .
2926                         ResourceLoaderClientHtml::makeLoad(
2927                                 ResourceLoaderContext::newDummyContext(),
2928                                 [ 'html5shiv' ],
2929                                 ResourceLoaderModule::TYPE_SCRIPTS,
2930                                 [ 'sync' => true ],
2931                                 $this->getCSPNonce()
2932                         ) .
2933                         '<![endif]-->';
2934
2935                 $pieces[] = Html::closeElement( 'head' );
2936
2937                 $bodyClasses = $this->mAdditionalBodyClasses;
2938                 $bodyClasses[] = 'mediawiki';
2939
2940                 # Classes for LTR/RTL directionality support
2941                 $bodyClasses[] = $userdir;
2942                 $bodyClasses[] = "sitedir-$sitedir";
2943
2944                 $underline = $this->getUser()->getOption( 'underline' );
2945                 if ( $underline < 2 ) {
2946                         // The following classes can be used here:
2947                         // * mw-underline-always
2948                         // * mw-underline-never
2949                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2950                 }
2951
2952                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2953                         # A <body> class is probably not the best way to do this . . .
2954                         $bodyClasses[] = 'capitalize-all-nouns';
2955                 }
2956
2957                 // Parser feature migration class
2958                 // The idea is that this will eventually be removed, after the wikitext
2959                 // which requires it is cleaned up.
2960                 $bodyClasses[] = 'mw-hide-empty-elt';
2961
2962                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2963                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2964                 $bodyClasses[] =
2965                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2966
2967                 $bodyAttrs = [];
2968                 // While the implode() is not strictly needed, it's used for backwards compatibility
2969                 // (this used to be built as a string and hooks likely still expect that).
2970                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2971
2972                 // Allow skins and extensions to add body attributes they need
2973                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2974                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2975
2976                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2977
2978                 return self::combineWrappedStrings( $pieces );
2979         }
2980
2981         /**
2982          * Get a ResourceLoader object associated with this OutputPage
2983          *
2984          * @return ResourceLoader
2985          */
2986         public function getResourceLoader() {
2987                 if ( is_null( $this->mResourceLoader ) ) {
2988                         $this->mResourceLoader = new ResourceLoader(
2989                                 $this->getConfig(),
2990                                 LoggerFactory::getInstance( 'resourceloader' )
2991                         );
2992                 }
2993                 return $this->mResourceLoader;
2994         }
2995
2996         /**
2997          * Explicily load or embed modules on a page.
2998          *
2999          * @param array|string $modules One or more module names
3000          * @param string $only ResourceLoaderModule TYPE_ class constant
3001          * @param array $extraQuery [optional] Array with extra query parameters for the request
3002          * @return string|WrappedStringList HTML
3003          */
3004         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
3005                 // Apply 'target' and 'origin' filters
3006                 $modules = $this->filterModules( (array)$modules, null, $only );
3007
3008                 return ResourceLoaderClientHtml::makeLoad(
3009                         $this->getRlClientContext(),
3010                         $modules,
3011                         $only,
3012                         $extraQuery,
3013                         $this->getCSPNonce()
3014                 );
3015         }
3016
3017         /**
3018          * Combine WrappedString chunks and filter out empty ones
3019          *
3020          * @param array $chunks
3021          * @return string|WrappedStringList HTML
3022          */
3023         protected static function combineWrappedStrings( array $chunks ) {
3024                 // Filter out empty values
3025                 $chunks = array_filter( $chunks, 'strlen' );
3026                 return WrappedString::join( "\n", $chunks );
3027         }
3028
3029         /**
3030          * JS stuff to put at the bottom of the `<body>`.
3031          * These are legacy scripts ($this->mScripts), and user JS.
3032          *
3033          * @return string|WrappedStringList HTML
3034          */
3035         public function getBottomScripts() {
3036                 $chunks = [];
3037                 $chunks[] = $this->getRlClient()->getBodyHtml();
3038
3039                 // Legacy non-ResourceLoader scripts
3040                 $chunks[] = $this->mScripts;
3041
3042                 if ( $this->limitReportJSData ) {
3043                         $chunks[] = ResourceLoader::makeInlineScript(
3044                                 ResourceLoader::makeConfigSetScript(
3045                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3046                                 ),
3047                                 $this->getCSPNonce()
3048                         );
3049                 }
3050
3051                 return self::combineWrappedStrings( $chunks );
3052         }
3053
3054         /**
3055          * Get the javascript config vars to include on this page
3056          *
3057          * @return array Array of javascript config vars
3058          * @since 1.23
3059          */
3060         public function getJsConfigVars() {
3061                 return $this->mJsConfigVars;
3062         }
3063
3064         /**
3065          * Add one or more variables to be set in mw.config in JavaScript
3066          *
3067          * @param string|array $keys Key or array of key/value pairs
3068          * @param mixed $value [optional] Value of the configuration variable
3069          */
3070         public function addJsConfigVars( $keys, $value = null ) {
3071                 if ( is_array( $keys ) ) {
3072                         foreach ( $keys as $key => $value ) {
3073                                 $this->mJsConfigVars[$key] = $value;
3074                         }
3075                         return;
3076                 }
3077
3078                 $this->mJsConfigVars[$keys] = $value;
3079         }
3080
3081         /**
3082          * Get an array containing the variables to be set in mw.config in JavaScript.
3083          *
3084          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3085          * - in other words, page-independent/site-wide variables (without state).
3086          * You will only be adding bloat to the html page and causing page caches to
3087          * have to be purged on configuration changes.
3088          * @return array
3089          */
3090         public function getJSVars() {
3091                 global $wgContLang;
3092
3093                 $curRevisionId = 0;
3094                 $articleId = 0;
3095                 $canonicalSpecialPageName = false; # T23115
3096
3097                 $title = $this->getTitle();
3098                 $ns = $title->getNamespace();
3099                 $canonicalNamespace = MWNamespace::exists( $ns )
3100                         ? MWNamespace::getCanonicalName( $ns )
3101                         : $title->getNsText();
3102
3103                 $sk = $this->getSkin();
3104                 // Get the relevant title so that AJAX features can use the correct page name
3105                 // when making API requests from certain special pages (T36972).
3106                 $relevantTitle = $sk->getRelevantTitle();
3107                 $relevantUser = $sk->getRelevantUser();
3108
3109                 if ( $ns == NS_SPECIAL ) {
3110                         list( $canonicalSpecialPageName, /*...*/ ) =
3111                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3112                 } elseif ( $this->canUseWikiPage() ) {
3113                         $wikiPage = $this->getWikiPage();
3114                         $curRevisionId = $wikiPage->getLatest();
3115                         $articleId = $wikiPage->getId();
3116                 }
3117
3118                 $lang = $title->getPageViewLanguage();
3119
3120                 // Pre-process information
3121                 $separatorTransTable = $lang->separatorTransformTable();
3122                 $separatorTransTable = $separatorTransTable ? $separatorTransTable : [];
3123                 $compactSeparatorTransTable = [
3124                         implode( "\t", array_keys( $separatorTransTable ) ),
3125                         implode( "\t", $separatorTransTable ),
3126                 ];
3127                 $digitTransTable = $lang->digitTransformTable();
3128                 $digitTransTable = $digitTransTable ? $digitTransTable : [];
3129                 $compactDigitTransTable = [
3130                         implode( "\t", array_keys( $digitTransTable ) ),
3131                         implode( "\t", $digitTransTable ),
3132                 ];
3133
3134                 $user = $this->getUser();
3135
3136                 $vars = [
3137                         'wgCanonicalNamespace' => $canonicalNamespace,
3138                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3139                         'wgNamespaceNumber' => $title->getNamespace(),
3140                         'wgPageName' => $title->getPrefixedDBkey(),
3141                         'wgTitle' => $title->getText(),
3142                         'wgCurRevisionId' => $curRevisionId,
3143                         'wgRevisionId' => (int)$this->getRevisionId(),
3144                         'wgArticleId' => $articleId,
3145                         'wgIsArticle' => $this->isArticle(),
3146                         'wgIsRedirect' => $title->isRedirect(),
3147                         'wgAction' => Action::getActionName( $this->getContext() ),
3148                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3149                         'wgUserGroups' => $user->getEffectiveGroups(),
3150                         'wgCategories' => $this->getCategories(),
3151                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3152                         'wgPageContentLanguage' => $lang->getCode(),
3153                         'wgPageContentModel' => $title->getContentModel(),
3154                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3155                         'wgDigitTransformTable' => $compactDigitTransTable,
3156                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3157                         'wgMonthNames' => $lang->getMonthNamesArray(),
3158                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3159                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3160                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3161                         'wgRequestId' => WebRequest::getRequestId(),
3162                 ];
3163
3164                 if ( $user->isLoggedIn() ) {
3165                         $vars['wgUserId'] = $user->getId();
3166                         $vars['wgUserEditCount'] = $user->getEditCount();
3167                         $userReg = $user->getRegistration();
3168                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3169                         // Get the revision ID of the oldest new message on the user's talk
3170                         // page. This can be used for constructing new message alerts on
3171                         // the client side.
3172                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3173                 }
3174
3175                 if ( $wgContLang->hasVariants() ) {
3176                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3177                 }
3178                 // Same test as SkinTemplate
3179                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3180                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3181
3182                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3183                         && $relevantTitle->quickUserCan( 'edit', $user )
3184                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3185
3186                 foreach ( $title->getRestrictionTypes() as $type ) {
3187                         // Following keys are set in $vars:
3188                         // wgRestrictionCreate, wgRestrictionEdit, wgRestrictionMove, wgRestrictionUpload
3189                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3190                 }
3191
3192                 if ( $title->isMainPage() ) {
3193                         $vars['wgIsMainPage'] = true;
3194                 }
3195
3196                 if ( $this->mRedirectedFrom ) {
3197                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3198                 }
3199
3200                 if ( $relevantUser ) {
3201                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3202                 }
3203
3204                 // Allow extensions to add their custom variables to the mw.config map.
3205                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3206                 // page-dependant but site-wide (without state).
3207                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3208                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3209
3210                 // Merge in variables from addJsConfigVars last
3211                 return array_merge( $vars, $this->getJsConfigVars() );
3212         }
3213
3214         /**
3215          * To make it harder for someone to slip a user a fake
3216          * JavaScript or CSS preview, a random token
3217          * is associated with the login session. If it's not
3218          * passed back with the preview request, we won't render
3219          * the code.
3220          *
3221          * @return bool
3222          */
3223         public function userCanPreview() {
3224                 $request = $this->getRequest();
3225                 if (
3226                         $request->getVal( 'action' ) !== 'submit' ||
3227                         !$request->wasPosted()
3228                 ) {
3229                         return false;
3230                 }
3231
3232                 $user = $this->getUser();
3233
3234                 if ( !$user->isLoggedIn() ) {
3235                         // Anons have predictable edit tokens
3236                         return false;
3237                 }
3238                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3239                         return false;
3240                 }
3241
3242                 $title = $this->getTitle();
3243                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3244                 if ( count( $errors ) !== 0 ) {
3245                         return false;
3246                 }
3247
3248                 return true;
3249         }
3250
3251         /**
3252          * @return array Array in format "link name or number => 'link html'".
3253          */
3254         public function getHeadLinksArray() {
3255                 global $wgVersion;
3256
3257                 $tags = [];
3258                 $config = $this->getConfig();
3259
3260                 $canonicalUrl = $this->mCanonicalUrl;
3261
3262                 $tags['meta-generator'] = Html::element( 'meta', [
3263                         'name' => 'generator',
3264                         'content' => "MediaWiki $wgVersion",
3265                 ] );
3266
3267                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3268                         // Per https://w3c.github.io/webappsec-referrer-policy/#unknown-policy-values
3269                         // fallbacks should come before the primary value so we need to reverse the array.
3270                         foreach ( array_reverse( (array)$config->get( 'ReferrerPolicy' ) ) as $i => $policy ) {
3271                                 $tags["meta-referrer-$i"] = Html::element( 'meta', [
3272                                         'name' => 'referrer',
3273                                         'content' => $policy,
3274                                 ] );
3275                         }
3276                 }
3277
3278                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3279                 if ( $p !== 'index,follow' ) {
3280                         // http://www.robotstxt.org/wc/meta-user.html
3281                         // Only show if it's different from the default robots policy
3282                         $tags['meta-robots'] = Html::element( 'meta', [
3283                                 'name' => 'robots',
3284                                 'content' => $p,
3285                         ] );
3286                 }
3287
3288                 foreach ( $this->mMetatags as $tag ) {
3289                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3290                                 $a = 'http-equiv';
3291                                 $tag[0] = substr( $tag[0], 5 );
3292                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3293                                 $a = 'property';
3294                         } else {
3295                                 $a = 'name';
3296                         }
3297                         $tagName = "meta-{$tag[0]}";
3298                         if ( isset( $tags[$tagName] ) ) {
3299                                 $tagName .= $tag[1];
3300                         }
3301                         $tags[$tagName] = Html::element( 'meta',
3302                                 [
3303                                         $a => $tag[0],
3304                                         'content' => $tag[1]
3305                                 ]
3306                         );
3307                 }
3308
3309                 foreach ( $this->mLinktags as $tag ) {
3310                         $tags[] = Html::element( 'link', $tag );
3311                 }
3312
3313                 # Universal edit button
3314                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3315                         $user = $this->getUser();
3316                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3317                                 && ( $this->getTitle()->exists() ||
3318                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3319                         ) {
3320                                 // Original UniversalEditButton
3321                                 $msg = $this->msg( 'edit' )->text();
3322                                 $tags['universal-edit-button'] = Html::element( 'link', [
3323                                         'rel' => 'alternate',
3324                                         'type' => 'application/x-wiki',
3325                                         'title' => $msg,
3326                                         'href' => $this->getTitle()->getEditURL(),
3327                                 ] );
3328                                 // Alternate edit link
3329                                 $tags['alternative-edit'] = Html::element( 'link', [
3330                                         'rel' => 'edit',
3331                                         'title' => $msg,
3332                                         'href' => $this->getTitle()->getEditURL(),
3333                                 ] );
3334                         }
3335                 }
3336
3337                 # Generally the order of the favicon and apple-touch-icon links
3338                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3339                 # uses whichever one appears later in the HTML source. Make sure
3340                 # apple-touch-icon is specified first to avoid this.
3341                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3342                         $tags['apple-touch-icon'] = Html::element( 'link', [
3343                                 'rel' => 'apple-touch-icon',
3344                                 'href' => $config->get( 'AppleTouchIcon' )
3345                         ] );
3346                 }
3347
3348                 if ( $config->get( 'Favicon' ) !== false ) {
3349                         $tags['favicon'] = Html::element( 'link', [
3350                                 'rel' => 'shortcut icon',
3351                                 'href' => $config->get( 'Favicon' )
3352                         ] );
3353                 }
3354
3355                 # OpenSearch description link
3356                 $tags['opensearch'] = Html::element( 'link', [
3357                         'rel' => 'search',
3358                         'type' => 'application/opensearchdescription+xml',
3359                         'href' => wfScript( 'opensearch_desc' ),
3360                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3361                 ] );
3362
3363                 # Real Simple Discovery link, provides auto-discovery information
3364                 # for the MediaWiki API (and potentially additional custom API
3365                 # support such as WordPress or Twitter-compatible APIs for a
3366                 # blogging extension, etc)
3367                 $tags['rsd'] = Html::element( 'link', [
3368                         'rel' => 'EditURI',
3369                         'type' => 'application/rsd+xml',
3370                         // Output a protocol-relative URL here if $wgServer is protocol-relative.
3371                         // Whether RSD accepts relative or protocol-relative URLs is completely
3372                         // undocumented, though.
3373                         'href' => wfExpandUrl( wfAppendQuery(
3374                                 wfScript( 'api' ),
3375                                 [ 'action' => 'rsd' ] ),
3376                                 PROTO_RELATIVE
3377                         ),
3378                 ] );
3379
3380                 # Language variants
3381                 if ( !$config->get( 'DisableLangConversion' ) ) {
3382                         $lang = $this->getTitle()->getPageLanguage();
3383                         if ( $lang->hasVariants() ) {
3384                                 $variants = $lang->getVariants();
3385                                 foreach ( $variants as $variant ) {
3386                                         $tags["variant-$variant"] = Html::element( 'link', [
3387                                                 'rel' => 'alternate',
3388                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3389                                                 'href' => $this->getTitle()->getLocalURL(
3390                                                         [ 'variant' => $variant ] )
3391                                                 ]
3392                                         );
3393                                 }
3394                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3395                                 $tags["variant-x-default"] = Html::element( 'link', [
3396                                         'rel' => 'alternate',
3397                                         'hreflang' => 'x-default',
3398                                         'href' => $this->getTitle()->getLocalURL() ] );
3399                         }
3400                 }
3401
3402                 # Copyright
3403                 if ( $this->copyrightUrl !== null ) {
3404                         $copyright = $this->copyrightUrl;
3405                 } else {
3406                         $copyright = '';
3407                         if ( $config->get( 'RightsPage' ) ) {
3408                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3409
3410                                 if ( $copy ) {
3411                                         $copyright = $copy->getLocalURL();
3412                                 }
3413                         }
3414
3415                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3416                                 $copyright = $config->get( 'RightsUrl' );
3417                         }
3418                 }
3419
3420                 if ( $copyright ) {
3421                         $tags['copyright'] = Html::element( 'link', [
3422                                 'rel' => 'license',
3423                                 'href' => $copyright ]
3424                         );
3425                 }
3426
3427                 # Feeds
3428                 if ( $config->get( 'Feed' ) ) {
3429                         $feedLinks = [];
3430
3431                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3432                                 # Use the page name for the title.  In principle, this could
3433                                 # lead to issues with having the same name for different feeds
3434                                 # corresponding to the same page, but we can't avoid that at
3435                                 # this low a level.
3436
3437                                 $feedLinks[] = $this->feedLink(
3438                                         $format,
3439                                         $link,
3440                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3441                                         $this->msg(
3442                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3443                                         )->text()
3444                                 );
3445                         }
3446
3447                         # Recent changes feed should appear on every page (except recentchanges,
3448                         # that would be redundant). Put it after the per-page feed to avoid
3449                         # changing existing behavior. It's still available, probably via a
3450                         # menu in your browser. Some sites might have a different feed they'd
3451                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3452                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3453                         # If so, use it instead.
3454                         $sitename = $config->get( 'Sitename' );
3455                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3456                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3457                                         // Note, this->feedLink escapes the url.
3458                                         $feedLinks[] = $this->feedLink(
3459                                                 $type,
3460                                                 $feedUrl,
3461                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3462                                         );
3463                                 }
3464                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3465                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3466                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3467                                         $feedLinks[] = $this->feedLink(
3468                                                 $format,
3469                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3470                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3471                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3472                                         );
3473                                 }
3474                         }
3475
3476                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3477                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3478                         # use OutputPage::addFeedLink() instead.
3479                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3480
3481                         $tags += $feedLinks;
3482                 }
3483
3484                 # Canonical URL
3485                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3486                         if ( $canonicalUrl !== false ) {
3487                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3488                         } else {
3489                                 if ( $this->isArticleRelated() ) {
3490                                         // This affects all requests where "setArticleRelated" is true. This is
3491                                         // typically all requests that show content (query title, curid, oldid, diff),
3492                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3493                                         // It does not apply to File pages and Special pages.
3494                                         // 'history' and 'info' actions address page metadata rather than the page
3495                                         // content itself, so they may not be canonicalized to the view page url.
3496                                         // TODO: this ought to be better encapsulated in the Action class.
3497                                         $action = Action::getActionName( $this->getContext() );
3498                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3499                                                 $query = "action={$action}";
3500                                         } else {
3501                                                 $query = '';
3502                                         }
3503                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3504                                 } else {
3505                                         $reqUrl = $this->getRequest()->getRequestURL();
3506                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3507                                 }
3508                         }
3509                 }
3510                 if ( $canonicalUrl !== false ) {
3511                         $tags[] = Html::element( 'link', [
3512                                 'rel' => 'canonical',
3513                                 'href' => $canonicalUrl
3514                         ] );
3515                 }
3516
3517                 return $tags;
3518         }
3519
3520         /**
3521          * Generate a "<link rel/>" for a feed.
3522          *
3523          * @param string $type Feed type
3524          * @param string $url URL to the feed
3525          * @param string $text Value of the "title" attribute
3526          * @return string HTML fragment
3527          */
3528         private function feedLink( $type, $url, $text ) {
3529                 return Html::element( 'link', [
3530                         'rel' => 'alternate',
3531                         'type' => "application/$type+xml",
3532                         'title' => $text,
3533                         'href' => $url ]
3534                 );
3535         }
3536
3537         /**
3538          * Add a local or specified stylesheet, with the given media options.
3539          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3540          *
3541          * @param string $style URL to the file
3542          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3543          * @param string $condition For IE conditional comments, specifying an IE version
3544          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3545          */
3546         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3547                 $options = [];
3548                 if ( $media ) {
3549                         $options['media'] = $media;
3550                 }
3551                 if ( $condition ) {
3552                         $options['condition'] = $condition;
3553                 }
3554                 if ( $dir ) {
3555                         $options['dir'] = $dir;
3556                 }
3557                 $this->styles[$style] = $options;
3558         }
3559
3560         /**
3561          * Adds inline CSS styles
3562          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3563          *
3564          * @param mixed $style_css Inline CSS
3565          * @param string $flip Set to 'flip' to flip the CSS if needed
3566          */
3567         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3568                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3569                         # If wanted, and the interface is right-to-left, flip the CSS
3570                         $style_css = CSSJanus::transform( $style_css, true, false );
3571                 }
3572                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3573         }
3574
3575         /**
3576          * Build exempt modules and legacy non-ResourceLoader styles.
3577          *
3578          * @return string|WrappedStringList HTML
3579          */
3580         protected function buildExemptModules() {
3581                 $chunks = [];
3582                 // Things that go after the ResourceLoaderDynamicStyles marker
3583                 $append = [];
3584
3585                 // We want site, private and user styles to override dynamically added styles from
3586                 // general modules, but we want dynamically added styles to override statically added
3587                 // style modules. So the order has to be:
3588                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3589                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3590                 // - ResourceLoaderDynamicStyles marker
3591                 // - site/private/user styles
3592
3593                 // Add legacy styles added through addStyle()/addInlineStyle() here
3594                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3595
3596                 $chunks[] = Html::element(
3597                         'meta',
3598                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3599                 );
3600
3601                 $separateReq = [ 'site.styles', 'user.styles' ];
3602                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3603                         // Combinable modules
3604                         $chunks[] = $this->makeResourceLoaderLink(
3605                                 array_diff( $moduleNames, $separateReq ),
3606                                 ResourceLoaderModule::TYPE_STYLES
3607                         );
3608
3609                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3610                                 // These require their own dedicated request in order to support "@import"
3611                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3612                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3613                                         ResourceLoaderModule::TYPE_STYLES
3614                                 );
3615                         }
3616                 }
3617
3618                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3619         }
3620
3621         /**
3622          * @return array
3623          */
3624         public function buildCssLinksArray() {
3625                 $links = [];
3626
3627                 foreach ( $this->styles as $file => $options ) {
3628                         $link = $this->styleLink( $file, $options );
3629                         if ( $link ) {
3630                                 $links[$file] = $link;
3631                         }
3632                 }
3633                 return $links;
3634         }
3635
3636         /**
3637          * Generate \<link\> tags for stylesheets
3638          *
3639          * @param string $style URL to the file
3640          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3641          * @return string HTML fragment
3642          */
3643         protected function styleLink( $style, array $options ) {
3644                 if ( isset( $options['dir'] ) ) {
3645                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3646                                 return '';
3647                         }
3648                 }
3649
3650                 if ( isset( $options['media'] ) ) {
3651                         $media = self::transformCssMedia( $options['media'] );
3652                         if ( is_null( $media ) ) {
3653                                 return '';
3654                         }
3655                 } else {
3656                         $media = 'all';
3657                 }
3658
3659                 if ( substr( $style, 0, 1 ) == '/' ||
3660                         substr( $style, 0, 5 ) == 'http:' ||
3661                         substr( $style, 0, 6 ) == 'https:' ) {
3662                         $url = $style;
3663                 } else {
3664                         $config = $this->getConfig();
3665                         $url = $config->get( 'StylePath' ) . '/' . $style . '?' .
3666                                 $config->get( 'StyleVersion' );
3667                 }
3668
3669                 $link = Html::linkedStyle( $url, $media );
3670
3671                 if ( isset( $options['condition'] ) ) {
3672                         $condition = htmlspecialchars( $options['condition'] );
3673                         $link = "<!--[if $condition]>$link<![endif]-->";
3674                 }
3675                 return $link;
3676         }
3677
3678         /**
3679          * Transform path to web-accessible static resource.
3680          *
3681          * This is used to add a validation hash as query string.
3682          * This aids various behaviors:
3683          *
3684          * - Put long Cache-Control max-age headers on responses for improved
3685          *   cache performance.
3686          * - Get the correct version of a file as expected by the current page.
3687          * - Instantly get the updated version of a file after deployment.
3688          *
3689          * Avoid using this for urls included in HTML as otherwise clients may get different
3690          * versions of a resource when navigating the site depending on when the page was cached.
3691          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3692          * an external stylesheet).
3693          *
3694          * @since 1.27
3695          * @param Config $config
3696          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3697          * @return string URL
3698          */
3699         public static function transformResourcePath( Config $config, $path ) {
3700                 global $IP;
3701
3702                 $localDir = $IP;
3703                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3704                 if ( $remotePathPrefix === '' ) {
3705                         // The configured base path is required to be empty string for
3706                         // wikis in the domain root
3707                         $remotePath = '/';
3708                 } else {
3709                         $remotePath = $remotePathPrefix;
3710                 }
3711                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3712                         // - Path is outside wgResourceBasePath, ignore.
3713                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3714                         return $path;
3715                 }
3716                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3717                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3718                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3719                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3720                 $uploadPath = $config->get( 'UploadPath' );
3721                 if ( strpos( $path, $uploadPath ) === 0 ) {
3722                         $localDir = $config->get( 'UploadDirectory' );
3723                         $remotePathPrefix = $remotePath = $uploadPath;
3724                 }
3725
3726                 $path = RelPath::getRelativePath( $path, $remotePath );
3727                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3728         }
3729
3730         /**
3731          * Utility method for transformResourceFilePath().
3732          *
3733          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3734          *
3735          * @since 1.27
3736          * @param string $remotePathPrefix URL path prefix that points to $localPath
3737          * @param string $localPath File directory exposed at $remotePath
3738          * @param string $file Path to target file relative to $localPath
3739          * @return string URL
3740          */
3741         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3742                 $hash = md5_file( "$localPath/$file" );
3743                 if ( $hash === false ) {
3744                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3745                         $hash = '';
3746                 }
3747                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3748         }
3749
3750         /**
3751          * Transform "media" attribute based on request parameters
3752          *
3753          * @param string $media Current value of the "media" attribute
3754          * @return string Modified value of the "media" attribute, or null to skip
3755          * this stylesheet
3756          */
3757         public static function transformCssMedia( $media ) {
3758                 global $wgRequest;
3759
3760                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3761                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3762
3763                 // Switch in on-screen display for media testing
3764                 $switches = [
3765                         'printable' => 'print',
3766                         'handheld' => 'handheld',
3767                 ];
3768                 foreach ( $switches as $switch => $targetMedia ) {
3769                         if ( $wgRequest->getBool( $switch ) ) {
3770                                 if ( $media == $targetMedia ) {
3771                                         $media = '';
3772                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3773                                         /* This regex will not attempt to understand a comma-separated media_query_list
3774                                          *
3775                                          * Example supported values for $media:
3776                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3777                                          * Example NOT supported value for $media:
3778                                          * '3d-glasses, screen, print and resolution > 90dpi'
3779                                          *
3780                                          * If it's a print request, we never want any kind of screen stylesheets
3781                                          * If it's a handheld request (currently the only other choice with a switch),
3782                                          * we don't want simple 'screen' but we might want screen queries that
3783                                          * have a max-width or something, so we'll pass all others on and let the
3784                                          * client do the query.
3785                                          */
3786                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3787                                                 return null;
3788                                         }
3789                                 }
3790                         }
3791                 }
3792
3793                 return $media;
3794         }
3795
3796         /**
3797          * Add a wikitext-formatted message to the output.
3798          * This is equivalent to:
3799          *
3800          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3801          */
3802         public function addWikiMsg( /*...*/ ) {
3803                 $args = func_get_args();
3804                 $name = array_shift( $args );
3805                 $this->addWikiMsgArray( $name, $args );
3806         }
3807
3808         /**
3809          * Add a wikitext-formatted message to the output.
3810          * Like addWikiMsg() except the parameters are taken as an array
3811          * instead of a variable argument list.
3812          *
3813          * @param string $name
3814          * @param array $args
3815          */
3816         public function addWikiMsgArray( $name, $args ) {
3817                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3818         }
3819
3820         /**
3821          * This function takes a number of message/argument specifications, wraps them in
3822          * some overall structure, and then parses the result and adds it to the output.
3823          *
3824          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3825          * and so on. The subsequent arguments may be either
3826          * 1) strings, in which case they are message names, or
3827          * 2) arrays, in which case, within each array, the first element is the message
3828          *    name, and subsequent elements are the parameters to that message.
3829          *
3830          * Don't use this for messages that are not in the user's interface language.
3831          *
3832          * For example:
3833          *
3834          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3835          *
3836          * Is equivalent to:
3837          *
3838          *    $wgOut->addWikiText( "<div class='error'>\n"
3839          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3840          *
3841          * The newline after the opening div is needed in some wikitext. See T21226.
3842          *
3843          * @param string $wrap
3844          */
3845         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3846                 $msgSpecs = func_get_args();
3847                 array_shift( $msgSpecs );
3848                 $msgSpecs = array_values( $msgSpecs );
3849                 $s = $wrap;
3850                 foreach ( $msgSpecs as $n => $spec ) {
3851                         if ( is_array( $spec ) ) {
3852                                 $args = $spec;
3853                                 $name = array_shift( $args );
3854                                 if ( isset( $args['options'] ) ) {
3855                                         unset( $args['options'] );
3856                                         wfDeprecated(
3857                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3858                                                 '1.20'
3859                                         );
3860                                 }
3861                         } else {
3862                                 $args = [];
3863                                 $name = $spec;
3864                         }
3865                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3866                 }
3867                 $this->addWikiText( $s );
3868         }
3869
3870         /**
3871          * Whether the output has a table of contents
3872          * @return bool
3873          * @since 1.22
3874          */
3875         public function isTOCEnabled() {
3876                 return $this->mEnableTOC;
3877         }
3878
3879         /**
3880          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3881          * @param bool $flag
3882          * @since 1.23
3883          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3884          */
3885         public function enableSectionEditLinks( $flag = true ) {
3886                 wfDeprecated( __METHOD__, '1.31' );
3887         }
3888
3889         /**
3890          * @return bool
3891          * @since 1.23
3892          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3893          */
3894         public function sectionEditLinksEnabled() {
3895                 wfDeprecated( __METHOD__, '1.31' );
3896                 return true;
3897         }
3898
3899         /**
3900          * Helper function to setup the PHP implementation of OOUI to use in this request.
3901          *
3902          * @since 1.26
3903          * @param String $skinName The Skin name to determine the correct OOUI theme
3904          * @param String $dir Language direction
3905          */
3906         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
3907                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
3908                 $theme = isset( $themes[$skinName] ) ? $themes[$skinName] : $themes['default'];
3909                 // For example, 'OOUI\WikimediaUITheme'.
3910                 $themeClass = "OOUI\\{$theme}Theme";
3911                 OOUI\Theme::setSingleton( new $themeClass() );
3912                 OOUI\Element::setDefaultDir( $dir );
3913         }
3914
3915         /**
3916          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3917          * MediaWiki and this OutputPage instance.
3918          *
3919          * @since 1.25
3920          */
3921         public function enableOOUI() {
3922                 self::setupOOUI(
3923                         strtolower( $this->getSkin()->getSkinName() ),
3924                         $this->getLanguage()->getDir()
3925                 );
3926                 $this->addModuleStyles( [
3927                         'oojs-ui-core.styles',
3928                         'oojs-ui.styles.indicators',
3929                         'oojs-ui.styles.textures',
3930                         'mediawiki.widgets.styles',
3931                         'oojs-ui.styles.icons-content',
3932                         'oojs-ui.styles.icons-alerts',
3933                         'oojs-ui.styles.icons-interactions',
3934                 ] );
3935         }
3936
3937         /**
3938          * Add Link headers for preloading the wiki's logo.
3939          *
3940          * @since 1.26
3941          */
3942         protected function addLogoPreloadLinkHeaders() {
3943                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
3944
3945                 $tags = [];
3946                 $logosPerDppx = [];
3947                 $logos = [];
3948
3949                 if ( !is_array( $logo ) ) {
3950                         // No media queries required if we only have one variant
3951                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
3952                         return;
3953                 }
3954
3955                 if ( isset( $logo['svg'] ) ) {
3956                         // No media queries required if we only have a 1x and svg variant
3957                         // because all preload-capable browsers support SVGs
3958                         $this->addLinkHeader( '<' . $logo['svg'] . '>;rel=preload;as=image' );
3959                         return;
3960                 }
3961
3962                 foreach ( $logo as $dppx => $src ) {
3963                         // Keys are in this format: "1.5x"
3964                         $dppx = substr( $dppx, 0, -1 );
3965                         $logosPerDppx[$dppx] = $src;
3966                 }
3967
3968                 // Because PHP can't have floats as array keys
3969                 uksort( $logosPerDppx, function ( $a , $b ) {
3970                         $a = floatval( $a );
3971                         $b = floatval( $b );
3972
3973                         if ( $a == $b ) {
3974                                 return 0;
3975                         }
3976                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
3977                         return ( $a < $b ) ? -1 : 1;
3978                 } );
3979
3980                 foreach ( $logosPerDppx as $dppx => $src ) {
3981                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
3982                 }
3983
3984                 $logosCount = count( $logos );
3985                 // Logic must match ResourceLoaderSkinModule:
3986                 // - 1x applies to resolution < 1.5dppx
3987                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
3988                 // - 2x applies to resolution >= 2dppx
3989                 // Note that min-resolution and max-resolution are both inclusive.
3990                 for ( $i = 0; $i < $logosCount; $i++ ) {
3991                         if ( $i === 0 ) {
3992                                 // Smallest dppx
3993                                 // min-resolution is ">=" (larger than or equal to)
3994                                 // "not min-resolution" is essentially "<"
3995                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
3996                         } elseif ( $i !== $logosCount - 1 ) {
3997                                 // In between
3998                                 // Media query expressions can only apply "not" to the entire expression
3999                                 // (e.g. can't express ">= 1.5 and not >= 2).
4000                                 // Workaround: Use <= 1.9999 in place of < 2.
4001                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
4002                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
4003                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
4004                         } else {
4005                                 // Largest dppx
4006                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
4007                         }
4008
4009                         $this->addLinkHeader(
4010                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
4011                         );
4012                 }
4013         }
4014
4015         /**
4016          * Get (and set if not yet set) the CSP nonce.
4017          *
4018          * This value needs to be included in any <script> tags on the
4019          * page.
4020          *
4021          * @return string|bool Nonce or false to mean don't output nonce
4022          * @since 1.32
4023          */
4024         public function getCSPNonce() {
4025                 if ( !ContentSecurityPolicy::isEnabled( $this->getConfig() ) ) {
4026                         return false;
4027                 }
4028                 if ( $this->CSPNonce === null ) {
4029                         // XXX It might be expensive to generate randomness
4030                         // on every request, on windows.
4031                         $rand = MWCryptRand::generate( 15 );
4032                         $this->CSPNonce = base64_encode( $rand );
4033                 }
4034                 return $this->CSPNonce;
4035         }
4036 }