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 $unused Previously used to change the cache-busting query parameter
 472          */
 473         public function addScriptFile( $file, $unused = 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                 $this->addScript( Html::linkedScript( $file, $this->getCSPNonce() ) );
 482         }
 483
 484         /**
 485          * Add a self-contained script tag with the given contents
 486          * Internal use only. Use OutputPage::addModules() if possible.
 487          *
 488          * @param string $script JavaScript text, no script tags
 489          */
 490         public function addInlineScript( $script ) {
 491                 $this->mScripts .= Html::inlineScript( "\n$script\n", $this->getCSPNonce() ) . "\n";
 492         }
 493
 494         /**
 495          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 496          * which are no longer registered (eg a page is cached before an extension is disabled)
 497          * @param array $modules
 498          * @param string|null $position Unused
 499          * @param string $type
 500          * @return array
 501          */
 502         protected function filterModules( array $modules, $position = null,
 503                 $type = ResourceLoaderModule::TYPE_COMBINED
 504         ) {
 505                 $resourceLoader = $this->getResourceLoader();
 506                 $filteredModules = [];
 507                 foreach ( $modules as $val ) {
 508                         $module = $resourceLoader->getModule( $val );
 509                         if ( $module instanceof ResourceLoaderModule
 510                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 511                         ) {
 512                                 if ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) ) {
 513                                         $this->warnModuleTargetFilter( $module->getName() );
 514                                         continue;
 515                                 }
 516                                 $filteredModules[] = $val;
 517                         }
 518                 }
 519                 return $filteredModules;
 520         }
 521
 522         private function warnModuleTargetFilter( $moduleName ) {
 523                 static $warnings = [];
 524                 if ( isset( $warnings[$this->mTarget][$moduleName] ) ) {
 525                         return;
 526                 }
 527                 $warnings[$this->mTarget][$moduleName] = true;
 528                 $this->getResourceLoader()->getLogger()->debug(
 529                         'Module "{module}" not loadable on target "{target}".',
 530                         [
 531                                 'module' => $moduleName,
 532                                 'target' => $this->mTarget,
 533                         ]
 534                 );
 535         }
 536
 537         /**
 538          * Get the list of modules to include on this page
 539          *
 540          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 541          * @param string|null $position Unused
 542          * @param string $param
 543          * @param string $type
 544          * @return array Array of module names
 545          */
 546         public function getModules( $filter = false, $position = null, $param = 'mModules',
 547                 $type = ResourceLoaderModule::TYPE_COMBINED
 548         ) {
 549                 $modules = array_values( array_unique( $this->$param ) );
 550                 return $filter
 551                         ? $this->filterModules( $modules, null, $type )
 552                         : $modules;
 553         }
 554
 555         /**
 556          * Load one or more ResourceLoader modules on this page.
 557          *
 558          * @param string|array $modules Module name (string) or array of module names
 559          */
 560         public function addModules( $modules ) {
 561                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 562         }
 563
 564         /**
 565          * Get the list of script-only modules to load on this page.
 566          *
 567          * @param bool $filter
 568          * @param string|null $position Unused
 569          * @return array Array of module names
 570          */
 571         public function getModuleScripts( $filter = false, $position = null ) {
 572                 return $this->getModules( $filter, null, 'mModuleScripts',
 573                         ResourceLoaderModule::TYPE_SCRIPTS
 574                 );
 575         }
 576
 577         /**
 578          * Load the scripts of one or more ResourceLoader modules, on this page.
 579          *
 580          * This method exists purely to provide the legacy behaviour of loading
 581          * a module's scripts in the global scope, and without dependency resolution.
 582          * See <https://phabricator.wikimedia.org/T188689>.
 583          *
 584          * @deprecated since 1.31 Use addModules() instead.
 585          * @param string|array $modules Module name (string) or array of module names
 586          */
 587         public function addModuleScripts( $modules ) {
 588                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 589         }
 590
 591         /**
 592          * Get the list of style-only modules to load on this page.
 593          *
 594          * @param bool $filter
 595          * @param string|null $position Unused
 596          * @return array Array of module names
 597          */
 598         public function getModuleStyles( $filter = false, $position = null ) {
 599                 return $this->getModules( $filter, null, 'mModuleStyles',
 600                         ResourceLoaderModule::TYPE_STYLES
 601                 );
 602         }
 603
 604         /**
 605          * Load the styles of one or more ResourceLoader modules on this page.
 606          *
 607          * Module styles added through this function will be loaded as a stylesheet,
 608          * using a standard `<link rel=stylesheet>` HTML tag, rather than as a combined
 609          * Javascript and CSS package. Thus, they will even load when JavaScript is disabled.
 610          *
 611          * @param string|array $modules Module name (string) or array of module names
 612          */
 613         public function addModuleStyles( $modules ) {
 614                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 615         }
 616
 617         /**
 618          * @return null|string ResourceLoader target
 619          */
 620         public function getTarget() {
 621                 return $this->mTarget;
 622         }
 623
 624         /**
 625          * Sets ResourceLoader target for load.php links. If null, will be omitted
 626          *
 627          * @param string|null $target
 628          */
 629         public function setTarget( $target ) {
 630                 $this->mTarget = $target;
 631         }
 632
 633         /**
 634          * Add a mapping from a LinkTarget to a Content, for things like page preview.
 635          * @see self::addContentOverrideCallback()
 636          * @since 1.32
 637          * @param LinkTarget $target
 638          * @param Content $content
 639          */
 640         public function addContentOverride( LinkTarget $target, Content $content ) {
 641                 if ( !$this->contentOverrides ) {
 642                         // Register a callback for $this->contentOverrides on the first call
 643                         $this->addContentOverrideCallback( function ( LinkTarget $target ) {
 644                                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 645                                 return $this->contentOverrides[$key] ?? null;
 646                         } );
 647                 }
 648
 649                 $key = $target->getNamespace() . ':' . $target->getDBkey();
 650                 $this->contentOverrides[$key] = $content;
 651         }
 652
 653         /**
 654          * Add a callback for mapping from a Title to a Content object, for things
 655          * like page preview.
 656          * @see ResourceLoaderContext::getContentOverrideCallback()
 657          * @since 1.32
 658          * @param callable $callback
 659          */
 660         public function addContentOverrideCallback( callable $callback ) {
 661                 $this->contentOverrideCallbacks[] = $callback;
 662         }
 663
 664         /**
 665          * Get an array of head items
 666          *
 667          * @return array
 668          */
 669         function getHeadItemsArray() {
 670                 return $this->mHeadItems;
 671         }
 672
 673         /**
 674          * Add or replace a head item to the output
 675          *
 676          * Whenever possible, use more specific options like ResourceLoader modules,
 677          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 678          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 679          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 680          * This would be your very LAST fallback.
 681          *
 682          * @param string $name Item name
 683          * @param string $value Raw HTML
 684          */
 685         public function addHeadItem( $name, $value ) {
 686                 $this->mHeadItems[$name] = $value;
 687         }
 688
 689         /**
 690          * Add one or more head items to the output
 691          *
 692          * @since 1.28
 693          * @param string|string[] $values Raw HTML
 694          */
 695         public function addHeadItems( $values ) {
 696                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 697         }
 698
 699         /**
 700          * Check if the header item $name is already set
 701          *
 702          * @param string $name Item name
 703          * @return bool
 704          */
 705         public function hasHeadItem( $name ) {
 706                 return isset( $this->mHeadItems[$name] );
 707         }
 708
 709         /**
 710          * Add a class to the <body> element
 711          *
 712          * @since 1.30
 713          * @param string|string[] $classes One or more classes to add
 714          */
 715         public function addBodyClasses( $classes ) {
 716                 $this->mAdditionalBodyClasses = array_merge( $this->mAdditionalBodyClasses, (array)$classes );
 717         }
 718
 719         /**
 720          * Set whether the output should only contain the body of the article,
 721          * without any skin, sidebar, etc.
 722          * Used e.g. when calling with "action=render".
 723          *
 724          * @param bool $only Whether to output only the body of the article
 725          */
 726         public function setArticleBodyOnly( $only ) {
 727                 $this->mArticleBodyOnly = $only;
 728         }
 729
 730         /**
 731          * Return whether the output will contain only the body of the article
 732          *
 733          * @return bool
 734          */
 735         public function getArticleBodyOnly() {
 736                 return $this->mArticleBodyOnly;
 737         }
 738
 739         /**
 740          * Set an additional output property
 741          * @since 1.21
 742          *
 743          * @param string $name
 744          * @param mixed $value
 745          */
 746         public function setProperty( $name, $value ) {
 747                 $this->mProperties[$name] = $value;
 748         }
 749
 750         /**
 751          * Get an additional output property
 752          * @since 1.21
 753          *
 754          * @param string $name
 755          * @return mixed Property value or null if not found
 756          */
 757         public function getProperty( $name ) {
 758                 return $this->mProperties[$name] ?? null;
 759         }
 760
 761         /**
 762          * checkLastModified tells the client to use the client-cached page if
 763          * possible. If successful, the OutputPage is disabled so that
 764          * any future call to OutputPage->output() have no effect.
 765          *
 766          * Side effect: sets mLastModified for Last-Modified header
 767          *
 768          * @param string $timestamp
 769          *
 770          * @return bool True if cache-ok headers was sent.
 771          */
 772         public function checkLastModified( $timestamp ) {
 773                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 774                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 775                         return false;
 776                 }
 777                 $config = $this->getConfig();
 778                 if ( !$config->get( 'CachePages' ) ) {
 779                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 780                         return false;
 781                 }
 782
 783                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 784                 $modifiedTimes = [
 785                         'page' => $timestamp,
 786                         'user' => $this->getUser()->getTouched(),
 787                         'epoch' => $config->get( 'CacheEpoch' )
 788                 ];
 789                 if ( $config->get( 'UseSquid' ) ) {
 790                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, $this->getCdnCacheEpoch(
 791                                 time(),
 792                                 $config->get( 'SquidMaxage' )
 793                         ) );
 794                 }
 795                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 796
 797                 $maxModified = max( $modifiedTimes );
 798                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 799
 800                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 801                 if ( $clientHeader === false ) {
 802                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 803                         return false;
 804                 }
 805
 806                 # IE sends sizes after the date like this:
 807                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 808                 # this breaks strtotime().
 809                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 810
 811                 Wikimedia\suppressWarnings(); // E_STRICT system time bitching
 812                 $clientHeaderTime = strtotime( $clientHeader );
 813                 Wikimedia\restoreWarnings();
 814                 if ( !$clientHeaderTime ) {
 815                         wfDebug( __METHOD__
 816                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 817                         return false;
 818                 }
 819                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 820
 821                 # Make debug info
 822                 $info = '';
 823                 foreach ( $modifiedTimes as $name => $value ) {
 824                         if ( $info !== '' ) {
 825                                 $info .= ', ';
 826                         }
 827                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 828                 }
 829
 830                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 831                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 832                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 833                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 834                 if ( $clientHeaderTime < $maxModified ) {
 835                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 836                         return false;
 837                 }
 838
 839                 # Not modified
 840                 # Give a 304 Not Modified response code and disable body output
 841                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 842                 ini_set( 'zlib.output_compression', 0 );
 843                 $this->getRequest()->response()->statusHeader( 304 );
 844                 $this->sendCacheControl();
 845                 $this->disable();
 846
 847                 // Don't output a compressed blob when using ob_gzhandler;
 848                 // it's technically against HTTP spec and seems to confuse
 849                 // Firefox when the response gets split over two packets.
 850                 wfClearOutputBuffers();
 851
 852                 return true;
 853         }
 854
 855         /**
 856          * @param int $reqTime Time of request (eg. now)
 857          * @param int $maxAge Cache TTL in seconds
 858          * @return int Timestamp
 859          */
 860         private function getCdnCacheEpoch( $reqTime, $maxAge ) {
 861                 // Ensure Last-Modified is never more than (wgSquidMaxage) in the past,
 862                 // because even if the wiki page content hasn't changed since, static
 863                 // resources may have changed (skin HTML, interface messages, urls, etc.)
 864                 // and must roll-over in a timely manner (T46570)
 865                 return $reqTime - $maxAge;
 866         }
 867
 868         /**
 869          * Override the last modified timestamp
 870          *
 871          * @param string $timestamp New timestamp, in a format readable by
 872          *        wfTimestamp()
 873          */
 874         public function setLastModified( $timestamp ) {
 875                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 876         }
 877
 878         /**
 879          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 880          *
 881          * @param string $policy The literal string to output as the contents of
 882          *   the meta tag.  Will be parsed according to the spec and output in
 883          *   standardized form.
 884          * @return null
 885          */
 886         public function setRobotPolicy( $policy ) {
 887                 $policy = Article::formatRobotPolicy( $policy );
 888
 889                 if ( isset( $policy['index'] ) ) {
 890                         $this->setIndexPolicy( $policy['index'] );
 891                 }
 892                 if ( isset( $policy['follow'] ) ) {
 893                         $this->setFollowPolicy( $policy['follow'] );
 894                 }
 895         }
 896
 897         /**
 898          * Set the index policy for the page, but leave the follow policy un-
 899          * touched.
 900          *
 901          * @param string $policy Either 'index' or 'noindex'.
 902          * @return null
 903          */
 904         public function setIndexPolicy( $policy ) {
 905                 $policy = trim( $policy );
 906                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 907                         $this->mIndexPolicy = $policy;
 908                 }
 909         }
 910
 911         /**
 912          * Set the follow policy for the page, but leave the index policy un-
 913          * touched.
 914          *
 915          * @param string $policy Either 'follow' or 'nofollow'.
 916          * @return null
 917          */
 918         public function setFollowPolicy( $policy ) {
 919                 $policy = trim( $policy );
 920                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 921                         $this->mFollowPolicy = $policy;
 922                 }
 923         }
 924
 925         /**
 926          * Set the new value of the "action text", this will be added to the
 927          * "HTML title", separated from it with " - ".
 928          *
 929          * @param string $text New value of the "action text"
 930          */
 931         public function setPageTitleActionText( $text ) {
 932                 $this->mPageTitleActionText = $text;
 933         }
 934
 935         /**
 936          * Get the value of the "action text"
 937          *
 938          * @return string
 939          */
 940         public function getPageTitleActionText() {
 941                 return $this->mPageTitleActionText;
 942         }
 943
 944         /**
 945          * "HTML title" means the contents of "<title>".
 946          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 947          *
 948          * @param string|Message $name
 949          */
 950         public function setHTMLTitle( $name ) {
 951                 if ( $name instanceof Message ) {
 952                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 953                 } else {
 954                         $this->mHTMLtitle = $name;
 955                 }
 956         }
 957
 958         /**
 959          * Return the "HTML title", i.e. the content of the "<title>" tag.
 960          *
 961          * @return string
 962          */
 963         public function getHTMLTitle() {
 964                 return $this->mHTMLtitle;
 965         }
 966
 967         /**
 968          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 969          *
 970          * @param Title $t
 971          */
 972         public function setRedirectedFrom( $t ) {
 973                 $this->mRedirectedFrom = $t;
 974         }
 975
 976         /**
 977          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 978          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 979          * but not bad tags like \<script\>. This function automatically sets
 980          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 981          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 982          * good tags like \<i\> will be dropped entirely.
 983          *
 984          * @param string|Message $name
 985          */
 986         public function setPageTitle( $name ) {
 987                 if ( $name instanceof Message ) {
 988                         $name = $name->setContext( $this->getContext() )->text();
 989                 }
 990
 991                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 992                 # but leave "<i>foobar</i>" alone
 993                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 994                 $this->mPagetitle = $nameWithTags;
 995
 996                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 997                 $this->setHTMLTitle(
 998                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 999                                 ->inContentLanguage()
1000                 );
1001         }
1002
1003         /**
1004          * Return the "page title", i.e. the content of the \<h1\> tag.
1005          *
1006          * @return string
1007          */
1008         public function getPageTitle() {
1009                 return $this->mPagetitle;
1010         }
1011
1012         /**
1013          * Set the Title object to use
1014          *
1015          * @param Title $t
1016          */
1017         public function setTitle( Title $t ) {
1018                 $this->getContext()->setTitle( $t );
1019         }
1020
1021         /**
1022          * Replace the subtitle with $str
1023          *
1024          * @param string|Message $str New value of the subtitle. String should be safe HTML.
1025          */
1026         public function setSubtitle( $str ) {
1027                 $this->clearSubtitle();
1028                 $this->addSubtitle( $str );
1029         }
1030
1031         /**
1032          * Add $str to the subtitle
1033          *
1034          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
1035          */
1036         public function addSubtitle( $str ) {
1037                 if ( $str instanceof Message ) {
1038                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
1039                 } else {
1040                         $this->mSubtitle[] = $str;
1041                 }
1042         }
1043
1044         /**
1045          * Build message object for a subtitle containing a backlink to a page
1046          *
1047          * @param Title $title Title to link to
1048          * @param array $query Array of additional parameters to include in the link
1049          * @return Message
1050          * @since 1.25
1051          */
1052         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1053                 if ( $title->isRedirect() ) {
1054                         $query['redirect'] = 'no';
1055                 }
1056                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1057                 return wfMessage( 'backlinksubtitle' )
1058                         ->rawParams( $linkRenderer->makeLink( $title, null, [], $query ) );
1059         }
1060
1061         /**
1062          * Add a subtitle containing a backlink to a page
1063          *
1064          * @param Title $title Title to link to
1065          * @param array $query Array of additional parameters to include in the link
1066          */
1067         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1068                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1069         }
1070
1071         /**
1072          * Clear the subtitles
1073          */
1074         public function clearSubtitle() {
1075                 $this->mSubtitle = [];
1076         }
1077
1078         /**
1079          * Get the subtitle
1080          *
1081          * @return string
1082          */
1083         public function getSubtitle() {
1084                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1085         }
1086
1087         /**
1088          * Set the page as printable, i.e. it'll be displayed with all
1089          * print styles included
1090          */
1091         public function setPrintable() {
1092                 $this->mPrintable = true;
1093         }
1094
1095         /**
1096          * Return whether the page is "printable"
1097          *
1098          * @return bool
1099          */
1100         public function isPrintable() {
1101                 return $this->mPrintable;
1102         }
1103
1104         /**
1105          * Disable output completely, i.e. calling output() will have no effect
1106          */
1107         public function disable() {
1108                 $this->mDoNothing = true;
1109         }
1110
1111         /**
1112          * Return whether the output will be completely disabled
1113          *
1114          * @return bool
1115          */
1116         public function isDisabled() {
1117                 return $this->mDoNothing;
1118         }
1119
1120         /**
1121          * Show an "add new section" link?
1122          *
1123          * @return bool
1124          */
1125         public function showNewSectionLink() {
1126                 return $this->mNewSectionLink;
1127         }
1128
1129         /**
1130          * Forcibly hide the new section link?
1131          *
1132          * @return bool
1133          */
1134         public function forceHideNewSectionLink() {
1135                 return $this->mHideNewSectionLink;
1136         }
1137
1138         /**
1139          * Add or remove feed links in the page header
1140          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1141          * for the new version
1142          * @see addFeedLink()
1143          *
1144          * @param bool $show True: add default feeds, false: remove all feeds
1145          */
1146         public function setSyndicated( $show = true ) {
1147                 if ( $show ) {
1148                         $this->setFeedAppendQuery( false );
1149                 } else {
1150                         $this->mFeedLinks = [];
1151                 }
1152         }
1153
1154         /**
1155          * Add default feeds to the page header
1156          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1157          * for the new version
1158          * @see addFeedLink()
1159          *
1160          * @param string $val Query to append to feed links or false to output
1161          *        default links
1162          */
1163         public function setFeedAppendQuery( $val ) {
1164                 $this->mFeedLinks = [];
1165
1166                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1167                         $query = "feed=$type";
1168                         if ( is_string( $val ) ) {
1169                                 $query .= '&' . $val;
1170                         }
1171                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1172                 }
1173         }
1174
1175         /**
1176          * Add a feed link to the page header
1177          *
1178          * @param string $format Feed type, should be a key of $wgFeedClasses
1179          * @param string $href URL
1180          */
1181         public function addFeedLink( $format, $href ) {
1182                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1183                         $this->mFeedLinks[$format] = $href;
1184                 }
1185         }
1186
1187         /**
1188          * Should we output feed links for this page?
1189          * @return bool
1190          */
1191         public function isSyndicated() {
1192                 return count( $this->mFeedLinks ) > 0;
1193         }
1194
1195         /**
1196          * Return URLs for each supported syndication format for this page.
1197          * @return array Associating format keys with URLs
1198          */
1199         public function getSyndicationLinks() {
1200                 return $this->mFeedLinks;
1201         }
1202
1203         /**
1204          * Will currently always return null
1205          *
1206          * @return null
1207          */
1208         public function getFeedAppendQuery() {
1209                 return $this->mFeedLinksAppendQuery;
1210         }
1211
1212         /**
1213          * Set whether the displayed content is related to the source of the
1214          * corresponding article on the wiki
1215          * Setting true will cause the change "article related" toggle to true
1216          *
1217          * @param bool $v
1218          */
1219         public function setArticleFlag( $v ) {
1220                 $this->mIsarticle = $v;
1221                 if ( $v ) {
1222                         $this->mIsArticleRelated = $v;
1223                 }
1224         }
1225
1226         /**
1227          * Return whether the content displayed page is related to the source of
1228          * the corresponding article on the wiki
1229          *
1230          * @return bool
1231          */
1232         public function isArticle() {
1233                 return $this->mIsarticle;
1234         }
1235
1236         /**
1237          * Set whether this page is related an article on the wiki
1238          * Setting false will cause the change of "article flag" toggle to false
1239          *
1240          * @param bool $v
1241          */
1242         public function setArticleRelated( $v ) {
1243                 $this->mIsArticleRelated = $v;
1244                 if ( !$v ) {
1245                         $this->mIsarticle = false;
1246                 }
1247         }
1248
1249         /**
1250          * Return whether this page is related an article on the wiki
1251          *
1252          * @return bool
1253          */
1254         public function isArticleRelated() {
1255                 return $this->mIsArticleRelated;
1256         }
1257
1258         /**
1259          * Add new language links
1260          *
1261          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1262          *                               (e.g. 'fr:Test page')
1263          */
1264         public function addLanguageLinks( array $newLinkArray ) {
1265                 $this->mLanguageLinks += $newLinkArray;
1266         }
1267
1268         /**
1269          * Reset the language links and 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 setLanguageLinks( array $newLinkArray ) {
1275                 $this->mLanguageLinks = $newLinkArray;
1276         }
1277
1278         /**
1279          * Get the list of language links
1280          *
1281          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1282          */
1283         public function getLanguageLinks() {
1284                 return $this->mLanguageLinks;
1285         }
1286
1287         /**
1288          * Add an array of categories, with names in the keys
1289          *
1290          * @param array $categories Mapping category name => sort key
1291          */
1292         public function addCategoryLinks( array $categories ) {
1293                 global $wgContLang;
1294
1295                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1296                         return;
1297                 }
1298
1299                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1300
1301                 # Set all the values to 'normal'.
1302                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1303
1304                 # Mark hidden categories
1305                 foreach ( $res as $row ) {
1306                         if ( isset( $row->pp_value ) ) {
1307                                 $categories[$row->page_title] = 'hidden';
1308                         }
1309                 }
1310
1311                 // Avoid PHP 7.1 warning of passing $this by reference
1312                 $outputPage = $this;
1313                 # Add the remaining categories to the skin
1314                 if ( Hooks::run(
1315                         'OutputPageMakeCategoryLinks',
1316                         [ &$outputPage, $categories, &$this->mCategoryLinks ] )
1317                 ) {
1318                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
1319                         foreach ( $categories as $category => $type ) {
1320                                 // array keys will cast numeric category names to ints, so cast back to string
1321                                 $category = (string)$category;
1322                                 $origcategory = $category;
1323                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1324                                 if ( !$title ) {
1325                                         continue;
1326                                 }
1327                                 $wgContLang->findVariantLink( $category, $title, true );
1328                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1329                                         continue;
1330                                 }
1331                                 $text = $wgContLang->convertHtml( $title->getText() );
1332                                 $this->mCategories[$type][] = $title->getText();
1333                                 $this->mCategoryLinks[$type][] = $linkRenderer->makeLink( $title, new HtmlArmor( $text ) );
1334                         }
1335                 }
1336         }
1337
1338         /**
1339          * @param array $categories
1340          * @return bool|ResultWrapper
1341          */
1342         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1343                 # Add the links to a LinkBatch
1344                 $arr = [ NS_CATEGORY => $categories ];
1345                 $lb = new LinkBatch;
1346                 $lb->setArray( $arr );
1347
1348                 # Fetch existence plus the hiddencat property
1349                 $dbr = wfGetDB( DB_REPLICA );
1350                 $fields = array_merge(
1351                         LinkCache::getSelectFields(),
1352                         [ 'page_namespace', 'page_title', 'pp_value' ]
1353                 );
1354
1355                 $res = $dbr->select( [ 'page', 'page_props' ],
1356                         $fields,
1357                         $lb->constructSet( 'page', $dbr ),
1358                         __METHOD__,
1359                         [],
1360                         [ 'page_props' => [ 'LEFT JOIN', [
1361                                 'pp_propname' => 'hiddencat',
1362                                 'pp_page = page_id'
1363                         ] ] ]
1364                 );
1365
1366                 # Add the results to the link cache
1367                 $lb->addResultToCache( LinkCache::singleton(), $res );
1368
1369                 return $res;
1370         }
1371
1372         /**
1373          * Reset the category links (but not the category list) and add $categories
1374          *
1375          * @param array $categories Mapping category name => sort key
1376          */
1377         public function setCategoryLinks( array $categories ) {
1378                 $this->mCategoryLinks = [];
1379                 $this->addCategoryLinks( $categories );
1380         }
1381
1382         /**
1383          * Get the list of category links, in a 2-D array with the following format:
1384          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1385          * hidden categories) and $link a HTML fragment with a link to the category
1386          * page
1387          *
1388          * @return array
1389          */
1390         public function getCategoryLinks() {
1391                 return $this->mCategoryLinks;
1392         }
1393
1394         /**
1395          * Get the list of category names this page belongs to.
1396          *
1397          * @param string $type The type of categories which should be returned. Possible values:
1398          *  * all: all categories of all types
1399          *  * hidden: only the hidden categories
1400          *  * normal: all categories, except hidden categories
1401          * @return array Array of strings
1402          */
1403         public function getCategories( $type = 'all' ) {
1404                 if ( $type === 'all' ) {
1405                         $allCategories = [];
1406                         foreach ( $this->mCategories as $categories ) {
1407                                 $allCategories = array_merge( $allCategories, $categories );
1408                         }
1409                         return $allCategories;
1410                 }
1411                 if ( !isset( $this->mCategories[$type] ) ) {
1412                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1413                 }
1414                 return $this->mCategories[$type];
1415         }
1416
1417         /**
1418          * Add an array of indicators, with their identifiers as array
1419          * keys and HTML contents as values.
1420          *
1421          * In case of duplicate keys, existing values are overwritten.
1422          *
1423          * @param array $indicators
1424          * @since 1.25
1425          */
1426         public function setIndicators( array $indicators ) {
1427                 $this->mIndicators = $indicators + $this->mIndicators;
1428                 // Keep ordered by key
1429                 ksort( $this->mIndicators );
1430         }
1431
1432         /**
1433          * Get the indicators associated with this page.
1434          *
1435          * The array will be internally ordered by item keys.
1436          *
1437          * @return array Keys: identifiers, values: HTML contents
1438          * @since 1.25
1439          */
1440         public function getIndicators() {
1441                 return $this->mIndicators;
1442         }
1443
1444         /**
1445          * Adds help link with an icon via page indicators.
1446          * Link target can be overridden by a local message containing a wikilink:
1447          * the message key is: lowercase action or special page name + '-helppage'.
1448          * @param string $to Target MediaWiki.org page title or encoded URL.
1449          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1450          * @since 1.25
1451          */
1452         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1453                 $this->addModuleStyles( 'mediawiki.helplink' );
1454                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1455
1456                 if ( $overrideBaseUrl ) {
1457                         $helpUrl = $to;
1458                 } else {
1459                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1460                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1461                 }
1462
1463                 $link = Html::rawElement(
1464                         'a',
1465                         [
1466                                 'href' => $helpUrl,
1467                                 'target' => '_blank',
1468                                 'class' => 'mw-helplink',
1469                         ],
1470                         $text
1471                 );
1472
1473                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1474         }
1475
1476         /**
1477          * Do not allow scripts which can be modified by wiki users to load on this page;
1478          * only allow scripts bundled with, or generated by, the software.
1479          * Site-wide styles are controlled by a config setting, since they can be
1480          * used to create a custom skin/theme, but not user-specific ones.
1481          *
1482          * @todo this should be given a more accurate name
1483          */
1484         public function disallowUserJs() {
1485                 $this->reduceAllowedModules(
1486                         ResourceLoaderModule::TYPE_SCRIPTS,
1487                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1488                 );
1489
1490                 // Site-wide styles are controlled by a config setting, see T73621
1491                 // for background on why. User styles are never allowed.
1492                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1493                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1494                 } else {
1495                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1496                 }
1497                 $this->reduceAllowedModules(
1498                         ResourceLoaderModule::TYPE_STYLES,
1499                         $styleOrigin
1500                 );
1501         }
1502
1503         /**
1504          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1505          * @see ResourceLoaderModule::$origin
1506          * @param string $type ResourceLoaderModule TYPE_ constant
1507          * @return int ResourceLoaderModule ORIGIN_ class constant
1508          */
1509         public function getAllowedModules( $type ) {
1510                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1511                         return min( array_values( $this->mAllowedModules ) );
1512                 } else {
1513                         return $this->mAllowedModules[$type] ?? ResourceLoaderModule::ORIGIN_ALL;
1514                 }
1515         }
1516
1517         /**
1518          * Limit the highest level of CSS/JS untrustworthiness allowed.
1519          *
1520          * If passed the same or a higher level than the current level of untrustworthiness set, the
1521          * level will remain unchanged.
1522          *
1523          * @param string $type
1524          * @param int $level ResourceLoaderModule class constant
1525          */
1526         public function reduceAllowedModules( $type, $level ) {
1527                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1528         }
1529
1530         /**
1531          * Prepend $text to the body HTML
1532          *
1533          * @param string $text HTML
1534          */
1535         public function prependHTML( $text ) {
1536                 $this->mBodytext = $text . $this->mBodytext;
1537         }
1538
1539         /**
1540          * Append $text to the body HTML
1541          *
1542          * @param string $text HTML
1543          */
1544         public function addHTML( $text ) {
1545                 $this->mBodytext .= $text;
1546         }
1547
1548         /**
1549          * Shortcut for adding an Html::element via addHTML.
1550          *
1551          * @since 1.19
1552          *
1553          * @param string $element
1554          * @param array $attribs
1555          * @param string $contents
1556          */
1557         public function addElement( $element, array $attribs = [], $contents = '' ) {
1558                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1559         }
1560
1561         /**
1562          * Clear the body HTML
1563          */
1564         public function clearHTML() {
1565                 $this->mBodytext = '';
1566         }
1567
1568         /**
1569          * Get the body HTML
1570          *
1571          * @return string HTML
1572          */
1573         public function getHTML() {
1574                 return $this->mBodytext;
1575         }
1576
1577         /**
1578          * Get/set the ParserOptions object to use for wikitext parsing
1579          *
1580          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1581          *   current ParserOption object. This parameter is deprecated since 1.31.
1582          * @return ParserOptions
1583          */
1584         public function parserOptions( $options = null ) {
1585                 if ( $options !== null ) {
1586                         wfDeprecated( __METHOD__ . ' with non-null $options', '1.31' );
1587                 }
1588
1589                 if ( $options !== null && !empty( $options->isBogus ) ) {
1590                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1591                         // been changed somehow, and keep it if so.
1592                         $anonPO = ParserOptions::newFromAnon();
1593                         $anonPO->setAllowUnsafeRawHtml( false );
1594                         if ( !$options->matches( $anonPO ) ) {
1595                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1596                                 $options->isBogus = false;
1597                         }
1598                 }
1599
1600                 if ( !$this->mParserOptions ) {
1601                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1602                                 // $wgUser isn't unstubbable yet, so don't try to get a
1603                                 // ParserOptions for it. And don't cache this ParserOptions
1604                                 // either.
1605                                 $po = ParserOptions::newFromAnon();
1606                                 $po->setAllowUnsafeRawHtml( false );
1607                                 $po->isBogus = true;
1608                                 if ( $options !== null ) {
1609                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1610                                 }
1611                                 return $po;
1612                         }
1613
1614                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1615                         $this->mParserOptions->setAllowUnsafeRawHtml( false );
1616                 }
1617
1618                 if ( $options !== null && !empty( $options->isBogus ) ) {
1619                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1620                         // thing.
1621                         return wfSetVar( $this->mParserOptions, null, true );
1622                 } else {
1623                         return wfSetVar( $this->mParserOptions, $options );
1624                 }
1625         }
1626
1627         /**
1628          * Set the revision ID which will be seen by the wiki text parser
1629          * for things such as embedded {{REVISIONID}} variable use.
1630          *
1631          * @param int|null $revid An positive integer, or null
1632          * @return mixed Previous value
1633          */
1634         public function setRevisionId( $revid ) {
1635                 $val = is_null( $revid ) ? null : intval( $revid );
1636                 return wfSetVar( $this->mRevisionId, $val );
1637         }
1638
1639         /**
1640          * Get the displayed revision ID
1641          *
1642          * @return int
1643          */
1644         public function getRevisionId() {
1645                 return $this->mRevisionId;
1646         }
1647
1648         /**
1649          * Set the timestamp of the revision which will be displayed. This is used
1650          * to avoid a extra DB call in Skin::lastModified().
1651          *
1652          * @param string|null $timestamp
1653          * @return mixed Previous value
1654          */
1655         public function setRevisionTimestamp( $timestamp ) {
1656                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1657         }
1658
1659         /**
1660          * Get the timestamp of displayed revision.
1661          * This will be null if not filled by setRevisionTimestamp().
1662          *
1663          * @return string|null
1664          */
1665         public function getRevisionTimestamp() {
1666                 return $this->mRevisionTimestamp;
1667         }
1668
1669         /**
1670          * Set the displayed file version
1671          *
1672          * @param File|bool $file
1673          * @return mixed Previous value
1674          */
1675         public function setFileVersion( $file ) {
1676                 $val = null;
1677                 if ( $file instanceof File && $file->exists() ) {
1678                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1679                 }
1680                 return wfSetVar( $this->mFileVersion, $val, true );
1681         }
1682
1683         /**
1684          * Get the displayed file version
1685          *
1686          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1687          */
1688         public function getFileVersion() {
1689                 return $this->mFileVersion;
1690         }
1691
1692         /**
1693          * Get the templates used on this page
1694          *
1695          * @return array (namespace => dbKey => revId)
1696          * @since 1.18
1697          */
1698         public function getTemplateIds() {
1699                 return $this->mTemplateIds;
1700         }
1701
1702         /**
1703          * Get the files used on this page
1704          *
1705          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1706          * @since 1.18
1707          */
1708         public function getFileSearchOptions() {
1709                 return $this->mImageTimeKeys;
1710         }
1711
1712         /**
1713          * Convert wikitext to HTML and add it to the buffer
1714          * Default assumes that the current page title will be used.
1715          *
1716          * @param string $text
1717          * @param bool $linestart Is this the start of a line?
1718          * @param bool $interface Is this text in the user interface language?
1719          * @throws MWException
1720          */
1721         public function addWikiText( $text, $linestart = true, $interface = true ) {
1722                 $title = $this->getTitle(); // Work around E_STRICT
1723                 if ( !$title ) {
1724                         throw new MWException( 'Title is null' );
1725                 }
1726                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1727         }
1728
1729         /**
1730          * Add wikitext with a custom Title object
1731          *
1732          * @param string $text Wikitext
1733          * @param Title &$title
1734          * @param bool $linestart Is this the start of a line?
1735          */
1736         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1737                 $this->addWikiTextTitle( $text, $title, $linestart );
1738         }
1739
1740         /**
1741          * Add wikitext with a custom Title object and tidy enabled.
1742          *
1743          * @param string $text Wikitext
1744          * @param Title &$title
1745          * @param bool $linestart Is this the start of a line?
1746          */
1747         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1748                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1749         }
1750
1751         /**
1752          * Add wikitext with tidy enabled
1753          *
1754          * @param string $text Wikitext
1755          * @param bool $linestart Is this the start of a line?
1756          */
1757         public function addWikiTextTidy( $text, $linestart = true ) {
1758                 $title = $this->getTitle();
1759                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1760         }
1761
1762         /**
1763          * Add wikitext with a custom Title object
1764          *
1765          * @param string $text Wikitext
1766          * @param Title $title
1767          * @param bool $linestart Is this the start of a line?
1768          * @param bool $tidy Whether to use tidy
1769          * @param bool $interface Whether it is an interface message
1770          *   (for example disables conversion)
1771          */
1772         public function addWikiTextTitle( $text, Title $title, $linestart,
1773                 $tidy = false, $interface = false
1774         ) {
1775                 global $wgParser;
1776
1777                 $popts = $this->parserOptions();
1778                 $oldTidy = $popts->setTidy( $tidy );
1779                 $popts->setInterfaceMessage( (bool)$interface );
1780
1781                 $parserOutput = $wgParser->getFreshParser()->parse(
1782                         $text, $title, $popts,
1783                         $linestart, true, $this->mRevisionId
1784                 );
1785
1786                 $popts->setTidy( $oldTidy );
1787
1788                 $this->addParserOutput( $parserOutput, [
1789                         'enableSectionEditLinks' => false,
1790                 ] );
1791         }
1792
1793         /**
1794          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1795          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1796          * and so on.
1797          *
1798          * @since 1.24
1799          * @param ParserOutput $parserOutput
1800          */
1801         public function addParserOutputMetadata( $parserOutput ) {
1802                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1803                 $this->addCategoryLinks( $parserOutput->getCategories() );
1804                 $this->setIndicators( $parserOutput->getIndicators() );
1805                 $this->mNewSectionLink = $parserOutput->getNewSection();
1806                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1807
1808                 if ( !$parserOutput->isCacheable() ) {
1809                         $this->enableClientCache( false );
1810                 }
1811                 $this->mNoGallery = $parserOutput->getNoGallery();
1812                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1813                 $this->addModules( $parserOutput->getModules() );
1814                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1815                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1816                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1817                 $this->mPreventClickjacking = $this->mPreventClickjacking
1818                         || $parserOutput->preventClickjacking();
1819
1820                 // Template versioning...
1821                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1822                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1823                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1824                         } else {
1825                                 $this->mTemplateIds[$ns] = $dbks;
1826                         }
1827                 }
1828                 // File versioning...
1829                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1830                         $this->mImageTimeKeys[$dbk] = $data;
1831                 }
1832
1833                 // Hooks registered in the object
1834                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1835                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1836                         list( $hookName, $data ) = $hookInfo;
1837                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1838                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1839                         }
1840                 }
1841
1842                 // Enable OOUI if requested via ParserOutput
1843                 if ( $parserOutput->getEnableOOUI() ) {
1844                         $this->enableOOUI();
1845                 }
1846
1847                 // Include parser limit report
1848                 if ( !$this->limitReportJSData ) {
1849                         $this->limitReportJSData = $parserOutput->getLimitReportJSData();
1850                 }
1851
1852                 // Link flags are ignored for now, but may in the future be
1853                 // used to mark individual language links.
1854                 $linkFlags = [];
1855                 // Avoid PHP 7.1 warning of passing $this by reference
1856                 $outputPage = $this;
1857                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1858                 Hooks::runWithoutAbort( 'OutputPageParserOutput', [ &$outputPage, $parserOutput ] );
1859
1860                 // This check must be after 'OutputPageParserOutput' runs in addParserOutputMetadata
1861                 // so that extensions may modify ParserOutput to toggle TOC.
1862                 // This cannot be moved to addParserOutputText because that is not
1863                 // called by EditPage for Preview.
1864                 if ( $parserOutput->getTOCHTML() ) {
1865                         $this->mEnableTOC = true;
1866                 }
1867         }
1868
1869         /**
1870          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1871          * ParserOutput object, without any other metadata.
1872          *
1873          * @since 1.24
1874          * @param ParserOutput $parserOutput
1875          * @param array $poOptions Options to ParserOutput::getText()
1876          */
1877         public function addParserOutputContent( $parserOutput, $poOptions = [] ) {
1878                 $this->addParserOutputText( $parserOutput, $poOptions );
1879
1880                 $this->addModules( $parserOutput->getModules() );
1881                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1882                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1883
1884                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1885         }
1886
1887         /**
1888          * Add the HTML associated with a ParserOutput object, without any metadata.
1889          *
1890          * @since 1.24
1891          * @param ParserOutput $parserOutput
1892          * @param array $poOptions Options to ParserOutput::getText()
1893          */
1894         public function addParserOutputText( $parserOutput, $poOptions = [] ) {
1895                 $text = $parserOutput->getText( $poOptions );
1896                 // Avoid PHP 7.1 warning of passing $this by reference
1897                 $outputPage = $this;
1898                 Hooks::runWithoutAbort( 'OutputPageBeforeHTML', [ &$outputPage, &$text ] );
1899                 $this->addHTML( $text );
1900         }
1901
1902         /**
1903          * Add everything from a ParserOutput object.
1904          *
1905          * @param ParserOutput $parserOutput
1906          * @param array $poOptions Options to ParserOutput::getText()
1907          */
1908         function addParserOutput( $parserOutput, $poOptions = [] ) {
1909                 $this->addParserOutputMetadata( $parserOutput );
1910                 $this->addParserOutputText( $parserOutput, $poOptions );
1911         }
1912
1913         /**
1914          * Add the output of a QuickTemplate to the output buffer
1915          *
1916          * @param QuickTemplate &$template
1917          */
1918         public function addTemplate( &$template ) {
1919                 $this->addHTML( $template->getHTML() );
1920         }
1921
1922         /**
1923          * Parse wikitext and return the HTML.
1924          *
1925          * @param string $text
1926          * @param bool $linestart Is this the start of a line?
1927          * @param bool $interface Use interface language ($wgLang instead of
1928          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1929          *   This also disables LanguageConverter.
1930          * @param Language $language Target language object, will override $interface
1931          * @throws MWException
1932          * @return string HTML
1933          */
1934         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1935                 global $wgParser;
1936
1937                 if ( is_null( $this->getTitle() ) ) {
1938                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1939                 }
1940
1941                 $popts = $this->parserOptions();
1942                 if ( $interface ) {
1943                         $popts->setInterfaceMessage( true );
1944                 }
1945                 if ( $language !== null ) {
1946                         $oldLang = $popts->setTargetLanguage( $language );
1947                 }
1948
1949                 $parserOutput = $wgParser->getFreshParser()->parse(
1950                         $text, $this->getTitle(), $popts,
1951                         $linestart, true, $this->mRevisionId
1952                 );
1953
1954                 if ( $interface ) {
1955                         $popts->setInterfaceMessage( false );
1956                 }
1957                 if ( $language !== null ) {
1958                         $popts->setTargetLanguage( $oldLang );
1959                 }
1960
1961                 return $parserOutput->getText( [
1962                         'enableSectionEditLinks' => false,
1963                 ] );
1964         }
1965
1966         /**
1967          * Parse wikitext, strip paragraphs, and return the HTML.
1968          *
1969          * @param string $text
1970          * @param bool $linestart Is this the start of a line?
1971          * @param bool $interface Use interface language ($wgLang instead of
1972          *   $wgContLang) while parsing language sensitive magic
1973          *   words like GRAMMAR and PLURAL
1974          * @return string HTML
1975          */
1976         public function parseInline( $text, $linestart = true, $interface = false ) {
1977                 $parsed = $this->parse( $text, $linestart, $interface );
1978                 return Parser::stripOuterParagraph( $parsed );
1979         }
1980
1981         /**
1982          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1983          *
1984          * @param int $maxage Maximum cache time on the CDN, in seconds.
1985          */
1986         public function setCdnMaxage( $maxage ) {
1987                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1988         }
1989
1990         /**
1991          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1992          *
1993          * @param int $maxage Maximum cache time on the CDN, in seconds
1994          * @since 1.27
1995          */
1996         public function lowerCdnMaxage( $maxage ) {
1997                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1998                 $this->setCdnMaxage( $this->mCdnMaxage );
1999         }
2000
2001         /**
2002          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
2003          *
2004          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
2005          * the TTL is higher the older the $mtime timestamp is. Essentially, the
2006          * TTL is 90% of the age of the object, subject to the min and max.
2007          *
2008          * @param string|int|float|bool|null $mtime Last-Modified timestamp
2009          * @param int $minTTL Mimimum TTL in seconds [default: 1 minute]
2010          * @param int $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
2011          * @return int TTL in seconds
2012          * @since 1.28
2013          */
2014         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
2015                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
2016                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
2017
2018                 if ( $mtime === null || $mtime === false ) {
2019                         return $minTTL; // entity does not exist
2020                 }
2021
2022                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
2023                 $adaptiveTTL = max( 0.9 * $age, $minTTL );
2024                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
2025
2026                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
2027
2028                 return $adaptiveTTL;
2029         }
2030
2031         /**
2032          * Use enableClientCache(false) to force it to send nocache headers
2033          *
2034          * @param bool $state
2035          *
2036          * @return bool
2037          */
2038         public function enableClientCache( $state ) {
2039                 return wfSetVar( $this->mEnableClientCache, $state );
2040         }
2041
2042         /**
2043          * Get the list of cookies that will influence on the cache
2044          *
2045          * @return array
2046          */
2047         function getCacheVaryCookies() {
2048                 static $cookies;
2049                 if ( $cookies === null ) {
2050                         $config = $this->getConfig();
2051                         $cookies = array_merge(
2052                                 SessionManager::singleton()->getVaryCookies(),
2053                                 [
2054                                         'forceHTTPS',
2055                                 ],
2056                                 $config->get( 'CacheVaryCookies' )
2057                         );
2058                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2059                 }
2060                 return $cookies;
2061         }
2062
2063         /**
2064          * Check if the request has a cache-varying cookie header
2065          * If it does, it's very important that we don't allow public caching
2066          *
2067          * @return bool
2068          */
2069         function haveCacheVaryCookies() {
2070                 $request = $this->getRequest();
2071                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2072                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2073                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2074                                 return true;
2075                         }
2076                 }
2077                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2078                 return false;
2079         }
2080
2081         /**
2082          * Add an HTTP header that will influence on the cache
2083          *
2084          * @param string $header Header name
2085          * @param string[]|null $option Options for the Key header. See
2086          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2087          * for the list of valid options.
2088          */
2089         public function addVaryHeader( $header, array $option = null ) {
2090                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2091                         $this->mVaryHeader[$header] = [];
2092                 }
2093                 if ( !is_array( $option ) ) {
2094                         $option = [];
2095                 }
2096                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2097         }
2098
2099         /**
2100          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2101          * such as Accept-Encoding or Cookie
2102          *
2103          * @return string
2104          */
2105         public function getVaryHeader() {
2106                 // If we vary on cookies, let's make sure it's always included here too.
2107                 if ( $this->getCacheVaryCookies() ) {
2108                         $this->addVaryHeader( 'Cookie' );
2109                 }
2110
2111                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2112                         $this->addVaryHeader( $header, $options );
2113                 }
2114                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2115         }
2116
2117         /**
2118          * Add an HTTP Link: header
2119          *
2120          * @param string $header Header value
2121          */
2122         public function addLinkHeader( $header ) {
2123                 $this->mLinkHeader[] = $header;
2124         }
2125
2126         /**
2127          * Return a Link: header. Based on the values of $mLinkHeader.
2128          *
2129          * @return string
2130          */
2131         public function getLinkHeader() {
2132                 if ( !$this->mLinkHeader ) {
2133                         return false;
2134                 }
2135
2136                 return 'Link: ' . implode( ',', $this->mLinkHeader );
2137         }
2138
2139         /**
2140          * Get a complete Key header
2141          *
2142          * @return string
2143          */
2144         public function getKeyHeader() {
2145                 $cvCookies = $this->getCacheVaryCookies();
2146
2147                 $cookiesOption = [];
2148                 foreach ( $cvCookies as $cookieName ) {
2149                         $cookiesOption[] = 'param=' . $cookieName;
2150                 }
2151                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2152
2153                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2154                         $this->addVaryHeader( $header, $options );
2155                 }
2156
2157                 $headers = [];
2158                 foreach ( $this->mVaryHeader as $header => $option ) {
2159                         $newheader = $header;
2160                         if ( is_array( $option ) && count( $option ) > 0 ) {
2161                                 $newheader .= ';' . implode( ';', $option );
2162                         }
2163                         $headers[] = $newheader;
2164                 }
2165                 $key = 'Key: ' . implode( ',', $headers );
2166
2167                 return $key;
2168         }
2169
2170         /**
2171          * T23672: Add Accept-Language to Vary and Key headers
2172          * if there's no 'variant' parameter existed in GET.
2173          *
2174          * For example:
2175          *   /w/index.php?title=Main_page should always be served; but
2176          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2177          */
2178         function addAcceptLanguage() {
2179                 $title = $this->getTitle();
2180                 if ( !$title instanceof Title ) {
2181                         return;
2182                 }
2183
2184                 $lang = $title->getPageLanguage();
2185                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2186                         $variants = $lang->getVariants();
2187                         $aloption = [];
2188                         foreach ( $variants as $variant ) {
2189                                 if ( $variant === $lang->getCode() ) {
2190                                         continue;
2191                                 } else {
2192                                         $aloption[] = 'substr=' . $variant;
2193
2194                                         // IE and some other browsers use BCP 47 standards in
2195                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2196                                         // We should handle these too.
2197                                         $variantBCP47 = LanguageCode::bcp47( $variant );
2198                                         if ( $variantBCP47 !== $variant ) {
2199                                                 $aloption[] = 'substr=' . $variantBCP47;
2200                                         }
2201                                 }
2202                         }
2203                         $this->addVaryHeader( 'Accept-Language', $aloption );
2204                 }
2205         }
2206
2207         /**
2208          * Set a flag which will cause an X-Frame-Options header appropriate for
2209          * edit pages to be sent. The header value is controlled by
2210          * $wgEditPageFrameOptions.
2211          *
2212          * This is the default for special pages. If you display a CSRF-protected
2213          * form on an ordinary view page, then you need to call this function.
2214          *
2215          * @param bool $enable
2216          */
2217         public function preventClickjacking( $enable = true ) {
2218                 $this->mPreventClickjacking = $enable;
2219         }
2220
2221         /**
2222          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2223          * This can be called from pages which do not contain any CSRF-protected
2224          * HTML form.
2225          */
2226         public function allowClickjacking() {
2227                 $this->mPreventClickjacking = false;
2228         }
2229
2230         /**
2231          * Get the prevent-clickjacking flag
2232          *
2233          * @since 1.24
2234          * @return bool
2235          */
2236         public function getPreventClickjacking() {
2237                 return $this->mPreventClickjacking;
2238         }
2239
2240         /**
2241          * Get the X-Frame-Options header value (without the name part), or false
2242          * if there isn't one. This is used by Skin to determine whether to enable
2243          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2244          *
2245          * @return string|false
2246          */
2247         public function getFrameOptions() {
2248                 $config = $this->getConfig();
2249                 if ( $config->get( 'BreakFrames' ) ) {
2250                         return 'DENY';
2251                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2252                         return $config->get( 'EditPageFrameOptions' );
2253                 }
2254                 return false;
2255         }
2256
2257         /**
2258          * Send cache control HTTP headers
2259          */
2260         public function sendCacheControl() {
2261                 $response = $this->getRequest()->response();
2262                 $config = $this->getConfig();
2263
2264                 $this->addVaryHeader( 'Cookie' );
2265                 $this->addAcceptLanguage();
2266
2267                 # don't serve compressed data to clients who can't handle it
2268                 # maintain different caches for logged-in users and non-logged in ones
2269                 $response->header( $this->getVaryHeader() );
2270
2271                 if ( $config->get( 'UseKeyHeader' ) ) {
2272                         $response->header( $this->getKeyHeader() );
2273                 }
2274
2275                 if ( $this->mEnableClientCache ) {
2276                         if (
2277                                 $config->get( 'UseSquid' ) &&
2278                                 !$response->hasCookies() &&
2279                                 !SessionManager::getGlobalSession()->isPersistent() &&
2280                                 !$this->isPrintable() &&
2281                                 $this->mCdnMaxage != 0 &&
2282                                 !$this->haveCacheVaryCookies()
2283                         ) {
2284                                 if ( $config->get( 'UseESI' ) ) {
2285                                         # We'll purge the proxy cache explicitly, but require end user agents
2286                                         # to revalidate against the proxy on each visit.
2287                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2288                                         wfDebug( __METHOD__ .
2289                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2290                                         # start with a shorter timeout for initial testing
2291                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2292                                         $response->header(
2293                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2294                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2295                                         );
2296                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2297                                 } else {
2298                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2299                                         # to revalidate against the proxy on each visit.
2300                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2301                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2302                                         wfDebug( __METHOD__ .
2303                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2304                                         # start with a shorter timeout for initial testing
2305                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2306                                         $response->header( "Cache-Control: " .
2307                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2308                                 }
2309                         } else {
2310                                 # We do want clients to cache if they can, but they *must* check for updates
2311                                 # on revisiting the page.
2312                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2313                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2314                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2315                         }
2316                         if ( $this->mLastModified ) {
2317                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2318                         }
2319                 } else {
2320                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2321
2322                         # In general, the absence of a last modified header should be enough to prevent
2323                         # the client from using its cache. We send a few other things just to make sure.
2324                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2325                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2326                         $response->header( 'Pragma: no-cache' );
2327                 }
2328         }
2329
2330         /**
2331          * Transfer styles and JavaScript modules from skin.
2332          *
2333          * @param Skin $sk to load modules for
2334          */
2335         public function loadSkinModules( $sk ) {
2336                 foreach ( $sk->getDefaultModules() as $group => $modules ) {
2337                         if ( $group === 'styles' ) {
2338                                 foreach ( $modules as $key => $moduleMembers ) {
2339                                         $this->addModuleStyles( $moduleMembers );
2340                                 }
2341                         } else {
2342                                 $this->addModules( $modules );
2343                         }
2344                 }
2345         }
2346
2347         /**
2348          * Finally, all the text has been munged and accumulated into
2349          * the object, let's actually output it:
2350          *
2351          * @param bool $return Set to true to get the result as a string rather than sending it
2352          * @return string|null
2353          * @throws Exception
2354          * @throws FatalError
2355          * @throws MWException
2356          */
2357         public function output( $return = false ) {
2358                 global $wgContLang;
2359
2360                 if ( $this->mDoNothing ) {
2361                         return $return ? '' : null;
2362                 }
2363
2364                 $response = $this->getRequest()->response();
2365                 $config = $this->getConfig();
2366
2367                 if ( $this->mRedirect != '' ) {
2368                         # Standards require redirect URLs to be absolute
2369                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2370
2371                         $redirect = $this->mRedirect;
2372                         $code = $this->mRedirectCode;
2373
2374                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2375                                 if ( $code == '301' || $code == '303' ) {
2376                                         if ( !$config->get( 'DebugRedirects' ) ) {
2377                                                 $response->statusHeader( $code );
2378                                         }
2379                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2380                                 }
2381                                 if ( $config->get( 'VaryOnXFP' ) ) {
2382                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2383                                 }
2384                                 $this->sendCacheControl();
2385
2386                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2387                                 if ( $config->get( 'DebugRedirects' ) ) {
2388                                         $url = htmlspecialchars( $redirect );
2389                                         print "<!DOCTYPE html>\n<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2390                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2391                                         print "</body>\n</html>\n";
2392                                 } else {
2393                                         $response->header( 'Location: ' . $redirect );
2394                                 }
2395                         }
2396
2397                         return $return ? '' : null;
2398                 } elseif ( $this->mStatusCode ) {
2399                         $response->statusHeader( $this->mStatusCode );
2400                 }
2401
2402                 # Buffer output; final headers may depend on later processing
2403                 ob_start();
2404
2405                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2406                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2407
2408                 if ( !$this->mArticleBodyOnly ) {
2409                         $sk = $this->getSkin();
2410
2411                         if ( $sk->shouldPreloadLogo() ) {
2412                                 $this->addLogoPreloadLinkHeaders();
2413                         }
2414                 }
2415
2416                 $linkHeader = $this->getLinkHeader();
2417                 if ( $linkHeader ) {
2418                         $response->header( $linkHeader );
2419                 }
2420
2421                 // Prevent framing, if requested
2422                 $frameOptions = $this->getFrameOptions();
2423                 if ( $frameOptions ) {
2424                         $response->header( "X-Frame-Options: $frameOptions" );
2425                 }
2426
2427                 ContentSecurityPolicy::sendHeaders( $this );
2428
2429                 if ( $this->mArticleBodyOnly ) {
2430                         echo $this->mBodytext;
2431                 } else {
2432                         // Enable safe mode if requested (T152169)
2433                         if ( $this->getRequest()->getBool( 'safemode' ) ) {
2434                                 $this->disallowUserJs();
2435                         }
2436
2437                         $sk = $this->getSkin();
2438                         $this->loadSkinModules( $sk );
2439
2440                         MWDebug::addModules( $this );
2441
2442                         // Avoid PHP 7.1 warning of passing $this by reference
2443                         $outputPage = $this;
2444                         // Hook that allows last minute changes to the output page, e.g.
2445                         // adding of CSS or Javascript by extensions.
2446                         Hooks::runWithoutAbort( 'BeforePageDisplay', [ &$outputPage, &$sk ] );
2447
2448                         try {
2449                                 $sk->outputPage();
2450                         } catch ( Exception $e ) {
2451                                 ob_end_clean(); // bug T129657
2452                                 throw $e;
2453                         }
2454                 }
2455
2456                 try {
2457                         // This hook allows last minute changes to final overall output by modifying output buffer
2458                         Hooks::runWithoutAbort( 'AfterFinalPageOutput', [ $this ] );
2459                 } catch ( Exception $e ) {
2460                         ob_end_clean(); // bug T129657
2461                         throw $e;
2462                 }
2463
2464                 $this->sendCacheControl();
2465
2466                 if ( $return ) {
2467                         return ob_get_clean();
2468                 } else {
2469                         ob_end_flush();
2470                         return null;
2471                 }
2472         }
2473
2474         /**
2475          * Prepare this object to display an error page; disable caching and
2476          * indexing, clear the current text and redirect, set the page's title
2477          * and optionally an custom HTML title (content of the "<title>" tag).
2478          *
2479          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2480          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2481          *                   optional, if not passed the "<title>" attribute will be
2482          *                   based on $pageTitle
2483          */
2484         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2485                 $this->setPageTitle( $pageTitle );
2486                 if ( $htmlTitle !== false ) {
2487                         $this->setHTMLTitle( $htmlTitle );
2488                 }
2489                 $this->setRobotPolicy( 'noindex,nofollow' );
2490                 $this->setArticleRelated( false );
2491                 $this->enableClientCache( false );
2492                 $this->mRedirect = '';
2493                 $this->clearSubtitle();
2494                 $this->clearHTML();
2495         }
2496
2497         /**
2498          * Output a standard error page
2499          *
2500          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2501          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2502          * showErrorPage( 'titlemsg', $messageObject );
2503          * showErrorPage( $titleMessageObject, $messageObject );
2504          *
2505          * @param string|Message $title Message key (string) for page title, or a Message object
2506          * @param string|Message $msg Message key (string) for page text, or a Message object
2507          * @param array $params Message parameters; ignored if $msg is a Message object
2508          */
2509         public function showErrorPage( $title, $msg, $params = [] ) {
2510                 if ( !$title instanceof Message ) {
2511                         $title = $this->msg( $title );
2512                 }
2513
2514                 $this->prepareErrorPage( $title );
2515
2516                 if ( $msg instanceof Message ) {
2517                         if ( $params !== [] ) {
2518                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2519                                         . 'is discarded when the $msg argument is a Message object instead of '
2520                                         . 'a string.', E_USER_NOTICE );
2521                         }
2522                         $this->addHTML( $msg->parseAsBlock() );
2523                 } else {
2524                         $this->addWikiMsgArray( $msg, $params );
2525                 }
2526
2527                 $this->returnToMain();
2528         }
2529
2530         /**
2531          * Output a standard permission error page
2532          *
2533          * @param array $errors Error message keys or [key, param...] arrays
2534          * @param string $action Action that was denied or null if unknown
2535          */
2536         public function showPermissionsErrorPage( array $errors, $action = null ) {
2537                 foreach ( $errors as $key => $error ) {
2538                         $errors[$key] = (array)$error;
2539                 }
2540
2541                 // For some action (read, edit, create and upload), display a "login to do this action"
2542                 // error if all of the following conditions are met:
2543                 // 1. the user is not logged in
2544                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2545                 // 3. the error can be avoided simply by logging in
2546                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2547                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2548                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2549                         && ( User::groupHasPermission( 'user', $action )
2550                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2551                 ) {
2552                         $displayReturnto = null;
2553
2554                         # Due to T34276, if a user does not have read permissions,
2555                         # $this->getTitle() will just give Special:Badtitle, which is
2556                         # not especially useful as a returnto parameter. Use the title
2557                         # from the request instead, if there was one.
2558                         $request = $this->getRequest();
2559                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2560                         if ( $action == 'edit' ) {
2561                                 $msg = 'whitelistedittext';
2562                                 $displayReturnto = $returnto;
2563                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2564                                 $msg = 'nocreatetext';
2565                         } elseif ( $action == 'upload' ) {
2566                                 $msg = 'uploadnologintext';
2567                         } else { # Read
2568                                 $msg = 'loginreqpagetext';
2569                                 $displayReturnto = Title::newMainPage();
2570                         }
2571
2572                         $query = [];
2573
2574                         if ( $returnto ) {
2575                                 $query['returnto'] = $returnto->getPrefixedText();
2576
2577                                 if ( !$request->wasPosted() ) {
2578                                         $returntoquery = $request->getValues();
2579                                         unset( $returntoquery['title'] );
2580                                         unset( $returntoquery['returnto'] );
2581                                         unset( $returntoquery['returntoquery'] );
2582                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2583                                 }
2584                         }
2585                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
2586                         $loginLink = $linkRenderer->makeKnownLink(
2587                                 SpecialPage::getTitleFor( 'Userlogin' ),
2588                                 $this->msg( 'loginreqlink' )->text(),
2589                                 [],
2590                                 $query
2591                         );
2592
2593                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2594                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2595
2596                         # Don't return to a page the user can't read otherwise
2597                         # we'll end up in a pointless loop
2598                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2599                                 $this->returnToMain( null, $displayReturnto );
2600                         }
2601                 } else {
2602                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2603                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2604                 }
2605         }
2606
2607         /**
2608          * Display an error page indicating that a given version of MediaWiki is
2609          * required to use it
2610          *
2611          * @param mixed $version The version of MediaWiki needed to use the page
2612          */
2613         public function versionRequired( $version ) {
2614                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2615
2616                 $this->addWikiMsg( 'versionrequiredtext', $version );
2617                 $this->returnToMain();
2618         }
2619
2620         /**
2621          * Format a list of error messages
2622          *
2623          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2624          * @param string $action Action that was denied or null if unknown
2625          * @return string The wikitext error-messages, formatted into a list.
2626          */
2627         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2628                 if ( $action == null ) {
2629                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2630                 } else {
2631                         $action_desc = $this->msg( "action-$action" )->plain();
2632                         $text = $this->msg(
2633                                 'permissionserrorstext-withaction',
2634                                 count( $errors ),
2635                                 $action_desc
2636                         )->plain() . "\n\n";
2637                 }
2638
2639                 if ( count( $errors ) > 1 ) {
2640                         $text .= '<ul class="permissions-errors">' . "\n";
2641
2642                         foreach ( $errors as $error ) {
2643                                 $text .= '<li>';
2644                                 $text .= $this->msg( ...$error )->plain();
2645                                 $text .= "</li>\n";
2646                         }
2647                         $text .= '</ul>';
2648                 } else {
2649                         $text .= "<div class=\"permissions-errors\">\n" .
2650                                         $this->msg( ...reset( $errors ) )->plain() .
2651                                         "\n</div>";
2652                 }
2653
2654                 return $text;
2655         }
2656
2657         /**
2658          * Show a warning about replica DB lag
2659          *
2660          * If the lag is higher than $wgSlaveLagCritical seconds,
2661          * then the warning is a bit more obvious. If the lag is
2662          * lower than $wgSlaveLagWarning, then no warning is shown.
2663          *
2664          * @param int $lag Slave lag
2665          */
2666         public function showLagWarning( $lag ) {
2667                 $config = $this->getConfig();
2668                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2669                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2670                         $message = $lag < $config->get( 'SlaveLagCritical' )
2671                                 ? 'lag-warn-normal'
2672                                 : 'lag-warn-high';
2673                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2674                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2675                 }
2676         }
2677
2678         public function showFatalError( $message ) {
2679                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2680
2681                 $this->addHTML( $message );
2682         }
2683
2684         public function showUnexpectedValueError( $name, $val ) {
2685                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2686         }
2687
2688         public function showFileCopyError( $old, $new ) {
2689                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2690         }
2691
2692         public function showFileRenameError( $old, $new ) {
2693                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2694         }
2695
2696         public function showFileDeleteError( $name ) {
2697                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2698         }
2699
2700         public function showFileNotFoundError( $name ) {
2701                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2702         }
2703
2704         /**
2705          * Add a "return to" link pointing to a specified title
2706          *
2707          * @param Title $title Title to link
2708          * @param array $query Query string parameters
2709          * @param string $text Text of the link (input is not escaped)
2710          * @param array $options Options array to pass to Linker
2711          */
2712         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2713                 $linkRenderer = MediaWikiServices::getInstance()
2714                         ->getLinkRendererFactory()->createFromLegacyOptions( $options );
2715                 $link = $this->msg( 'returnto' )->rawParams(
2716                         $linkRenderer->makeLink( $title, $text, [], $query ) )->escaped();
2717                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2718         }
2719
2720         /**
2721          * Add a "return to" link pointing to a specified title,
2722          * or the title indicated in the request, or else the main page
2723          *
2724          * @param mixed $unused
2725          * @param Title|string $returnto Title or String to return to
2726          * @param string $returntoquery Query string for the return to link
2727          */
2728         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2729                 if ( $returnto == null ) {
2730                         $returnto = $this->getRequest()->getText( 'returnto' );
2731                 }
2732
2733                 if ( $returntoquery == null ) {
2734                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2735                 }
2736
2737                 if ( $returnto === '' ) {
2738                         $returnto = Title::newMainPage();
2739                 }
2740
2741                 if ( is_object( $returnto ) ) {
2742                         $titleObj = $returnto;
2743                 } else {
2744                         $titleObj = Title::newFromText( $returnto );
2745                 }
2746                 // We don't want people to return to external interwiki. That
2747                 // might potentially be used as part of a phishing scheme
2748                 if ( !is_object( $titleObj ) || $titleObj->isExternal() ) {
2749                         $titleObj = Title::newMainPage();
2750                 }
2751
2752                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2753         }
2754
2755         private function getRlClientContext() {
2756                 if ( !$this->rlClientContext ) {
2757                         $query = ResourceLoader::makeLoaderQuery(
2758                                 [], // modules; not relevant
2759                                 $this->getLanguage()->getCode(),
2760                                 $this->getSkin()->getSkinName(),
2761                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2762                                 null, // version; not relevant
2763                                 ResourceLoader::inDebugMode(),
2764                                 null, // only; not relevant
2765                                 $this->isPrintable(),
2766                                 $this->getRequest()->getBool( 'handheld' )
2767                         );
2768                         $this->rlClientContext = new ResourceLoaderContext(
2769                                 $this->getResourceLoader(),
2770                                 new FauxRequest( $query )
2771                         );
2772                         if ( $this->contentOverrideCallbacks ) {
2773                                 $this->rlClientContext = new DerivativeResourceLoaderContext( $this->rlClientContext );
2774                                 $this->rlClientContext->setContentOverrideCallback( function ( Title $title ) {
2775                                         foreach ( $this->contentOverrideCallbacks as $callback ) {
2776                                                 $content = call_user_func( $callback, $title );
2777                                                 if ( $content !== null ) {
2778                                                         return $content;
2779                                                 }
2780                                         }
2781                                         return null;
2782                                 } );
2783                         }
2784                 }
2785                 return $this->rlClientContext;
2786         }
2787
2788         /**
2789          * Call this to freeze the module queue and JS config and create a formatter.
2790          *
2791          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2792          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2793          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2794          * the module filters retroactively. Skins and extension hooks may also add modules until very
2795          * late in the request lifecycle.
2796          *
2797          * @return ResourceLoaderClientHtml
2798          */
2799         public function getRlClient() {
2800                 if ( !$this->rlClient ) {
2801                         $context = $this->getRlClientContext();
2802                         $rl = $this->getResourceLoader();
2803                         $this->addModules( [
2804                                 'user',
2805                                 'user.options',
2806                                 'user.tokens',
2807                         ] );
2808                         $this->addModuleStyles( [
2809                                 'site.styles',
2810                                 'noscript',
2811                                 'user.styles',
2812                         ] );
2813                         $this->getSkin()->setupSkinUserCss( $this );
2814
2815                         // Prepare exempt modules for buildExemptModules()
2816                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2817                         $exemptStates = [];
2818                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2819
2820                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2821                         // Separate user-specific batch for improved cache-hit ratio.
2822                         $userBatch = [ 'user.styles', 'user' ];
2823                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2824                         $dbr = wfGetDB( DB_REPLICA );
2825                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2826                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2827
2828                         // Filter out modules handled by buildExemptModules()
2829                         $moduleStyles = array_filter( $moduleStyles,
2830                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2831                                         $module = $rl->getModule( $name );
2832                                         if ( $module ) {
2833                                                 $group = $module->getGroup();
2834                                                 if ( isset( $exemptGroups[$group] ) ) {
2835                                                         $exemptStates[$name] = 'ready';
2836                                                         if ( !$module->isKnownEmpty( $context ) ) {
2837                                                                 // E.g. Don't output empty <styles>
2838                                                                 $exemptGroups[$group][] = $name;
2839                                                         }
2840                                                         return false;
2841                                                 }
2842                                         }
2843                                         return true;
2844                                 }
2845                         );
2846                         $this->rlExemptStyleModules = $exemptGroups;
2847
2848                         $rlClient = new ResourceLoaderClientHtml( $context, [
2849                                 'target' => $this->getTarget(),
2850                                 'nonce' => $this->getCSPNonce(),
2851                                 // When 'safemode', disallowUserJs(), or reduceAllowedModules() is used
2852                                 // to only restrict modules to ORIGIN_CORE (ie. disallow ORIGIN_USER), the list of
2853                                 // modules enqueud for loading on this page is filtered to just those.
2854                                 // However, to make sure we also apply the restriction to dynamic dependencies and
2855                                 // lazy-loaded modules at run-time on the client-side, pass 'safemode' down to the
2856                                 // StartupModule so that the client-side registry will not contain any restricted
2857                                 // modules either. (T152169, T185303)
2858                                 'safemode' => ( $this->getAllowedModules( ResourceLoaderModule::TYPE_COMBINED )
2859                                         <= ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
2860                                 ) ? '1' : null,
2861                         ] );
2862                         $rlClient->setConfig( $this->getJSVars() );
2863                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2864                         $rlClient->setModuleStyles( $moduleStyles );
2865                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2866                         $rlClient->setExemptStates( $exemptStates );
2867                         $this->rlClient = $rlClient;
2868                 }
2869                 return $this->rlClient;
2870         }
2871
2872         /**
2873          * @param Skin $sk The given Skin
2874          * @param bool $includeStyle Unused
2875          * @return string The doctype, opening "<html>", and head element.
2876          */
2877         public function headElement( Skin $sk, $includeStyle = true ) {
2878                 global $wgContLang;
2879
2880                 $userdir = $this->getLanguage()->getDir();
2881                 $sitedir = $wgContLang->getDir();
2882
2883                 $pieces = [];
2884                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2885                         $this->getRlClient()->getDocumentAttributes(),
2886                         $sk->getHtmlElementAttributes()
2887                 ) );
2888                 $pieces[] = Html::openElement( 'head' );
2889
2890                 if ( $this->getHTMLTitle() == '' ) {
2891                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2892                 }
2893
2894                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2895                         // Add <meta charset="UTF-8">
2896                         // This should be before <title> since it defines the charset used by
2897                         // text including the text inside <title>.
2898                         // The spec recommends defining XHTML5's charset using the XML declaration
2899                         // instead of meta.
2900                         // Our XML declaration is output by Html::htmlHeader.
2901                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2902                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2903                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2904                 }
2905
2906                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2907                 $pieces[] = $this->getRlClient()->getHeadHtml();
2908                 $pieces[] = $this->buildExemptModules();
2909                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2910                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2911
2912                 // Use an IE conditional comment to serve the script only to old IE
2913                 $pieces[] = '<!--[if lt IE 9]>' .
2914                         ResourceLoaderClientHtml::makeLoad(
2915                                 ResourceLoaderContext::newDummyContext(),
2916                                 [ 'html5shiv' ],
2917                                 ResourceLoaderModule::TYPE_SCRIPTS,
2918                                 [ 'sync' => true ],
2919                                 $this->getCSPNonce()
2920                         ) .
2921                         '<![endif]-->';
2922
2923                 $pieces[] = Html::closeElement( 'head' );
2924
2925                 $bodyClasses = $this->mAdditionalBodyClasses;
2926                 $bodyClasses[] = 'mediawiki';
2927
2928                 # Classes for LTR/RTL directionality support
2929                 $bodyClasses[] = $userdir;
2930                 $bodyClasses[] = "sitedir-$sitedir";
2931
2932                 $underline = $this->getUser()->getOption( 'underline' );
2933                 if ( $underline < 2 ) {
2934                         // The following classes can be used here:
2935                         // * mw-underline-always
2936                         // * mw-underline-never
2937                         $bodyClasses[] = 'mw-underline-' . ( $underline ? 'always' : 'never' );
2938                 }
2939
2940                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2941                         # A <body> class is probably not the best way to do this . . .
2942                         $bodyClasses[] = 'capitalize-all-nouns';
2943                 }
2944
2945                 // Parser feature migration class
2946                 // The idea is that this will eventually be removed, after the wikitext
2947                 // which requires it is cleaned up.
2948                 $bodyClasses[] = 'mw-hide-empty-elt';
2949
2950                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2951                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2952                 $bodyClasses[] =
2953                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2954
2955                 $bodyAttrs = [];
2956                 // While the implode() is not strictly needed, it's used for backwards compatibility
2957                 // (this used to be built as a string and hooks likely still expect that).
2958                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2959
2960                 // Allow skins and extensions to add body attributes they need
2961                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2962                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2963
2964                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2965
2966                 return self::combineWrappedStrings( $pieces );
2967         }
2968
2969         /**
2970          * Get a ResourceLoader object associated with this OutputPage
2971          *
2972          * @return ResourceLoader
2973          */
2974         public function getResourceLoader() {
2975                 if ( is_null( $this->mResourceLoader ) ) {
2976                         $this->mResourceLoader = new ResourceLoader(
2977                                 $this->getConfig(),
2978                                 LoggerFactory::getInstance( 'resourceloader' )
2979                         );
2980                 }
2981                 return $this->mResourceLoader;
2982         }
2983
2984         /**
2985          * Explicily load or embed modules on a page.
2986          *
2987          * @param array|string $modules One or more module names
2988          * @param string $only ResourceLoaderModule TYPE_ class constant
2989          * @param array $extraQuery [optional] Array with extra query parameters for the request
2990          * @return string|WrappedStringList HTML
2991          */
2992         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2993                 // Apply 'target' and 'origin' filters
2994                 $modules = $this->filterModules( (array)$modules, null, $only );
2995
2996                 return ResourceLoaderClientHtml::makeLoad(
2997                         $this->getRlClientContext(),
2998                         $modules,
2999                         $only,
3000                         $extraQuery,
3001                         $this->getCSPNonce()
3002                 );
3003         }
3004
3005         /**
3006          * Combine WrappedString chunks and filter out empty ones
3007          *
3008          * @param array $chunks
3009          * @return string|WrappedStringList HTML
3010          */
3011         protected static function combineWrappedStrings( array $chunks ) {
3012                 // Filter out empty values
3013                 $chunks = array_filter( $chunks, 'strlen' );
3014                 return WrappedString::join( "\n", $chunks );
3015         }
3016
3017         /**
3018          * JS stuff to put at the bottom of the `<body>`.
3019          * These are legacy scripts ($this->mScripts), and user JS.
3020          *
3021          * @return string|WrappedStringList HTML
3022          */
3023         public function getBottomScripts() {
3024                 $chunks = [];
3025                 $chunks[] = $this->getRlClient()->getBodyHtml();
3026
3027                 // Legacy non-ResourceLoader scripts
3028                 $chunks[] = $this->mScripts;
3029
3030                 if ( $this->limitReportJSData ) {
3031                         $chunks[] = ResourceLoader::makeInlineScript(
3032                                 ResourceLoader::makeConfigSetScript(
3033                                         [ 'wgPageParseReport' => $this->limitReportJSData ]
3034                                 ),
3035                                 $this->getCSPNonce()
3036                         );
3037                 }
3038
3039                 return self::combineWrappedStrings( $chunks );
3040         }
3041
3042         /**
3043          * Get the javascript config vars to include on this page
3044          *
3045          * @return array Array of javascript config vars
3046          * @since 1.23
3047          */
3048         public function getJsConfigVars() {
3049                 return $this->mJsConfigVars;
3050         }
3051
3052         /**
3053          * Add one or more variables to be set in mw.config in JavaScript
3054          *
3055          * @param string|array $keys Key or array of key/value pairs
3056          * @param mixed $value [optional] Value of the configuration variable
3057          */
3058         public function addJsConfigVars( $keys, $value = null ) {
3059                 if ( is_array( $keys ) ) {
3060                         foreach ( $keys as $key => $value ) {
3061                                 $this->mJsConfigVars[$key] = $value;
3062                         }
3063                         return;
3064                 }
3065
3066                 $this->mJsConfigVars[$keys] = $value;
3067         }
3068
3069         /**
3070          * Get an array containing the variables to be set in mw.config in JavaScript.
3071          *
3072          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3073          * - in other words, page-independent/site-wide variables (without state).
3074          * You will only be adding bloat to the html page and causing page caches to
3075          * have to be purged on configuration changes.
3076          * @return array
3077          */
3078         public function getJSVars() {
3079                 global $wgContLang;
3080
3081                 $curRevisionId = 0;
3082                 $articleId = 0;
3083                 $canonicalSpecialPageName = false; # T23115
3084
3085                 $title = $this->getTitle();
3086                 $ns = $title->getNamespace();
3087                 $canonicalNamespace = MWNamespace::exists( $ns )
3088                         ? MWNamespace::getCanonicalName( $ns )
3089                         : $title->getNsText();
3090
3091                 $sk = $this->getSkin();
3092                 // Get the relevant title so that AJAX features can use the correct page name
3093                 // when making API requests from certain special pages (T36972).
3094                 $relevantTitle = $sk->getRelevantTitle();
3095                 $relevantUser = $sk->getRelevantUser();
3096
3097                 if ( $ns == NS_SPECIAL ) {
3098                         list( $canonicalSpecialPageName, /*...*/ ) =
3099                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3100                 } elseif ( $this->canUseWikiPage() ) {
3101                         $wikiPage = $this->getWikiPage();
3102                         $curRevisionId = $wikiPage->getLatest();
3103                         $articleId = $wikiPage->getId();
3104                 }
3105
3106                 $lang = $title->getPageViewLanguage();
3107
3108                 // Pre-process information
3109                 $separatorTransTable = $lang->separatorTransformTable();
3110                 $separatorTransTable = $separatorTransTable ?: [];
3111                 $compactSeparatorTransTable = [
3112                         implode( "\t", array_keys( $separatorTransTable ) ),
3113                         implode( "\t", $separatorTransTable ),
3114                 ];
3115                 $digitTransTable = $lang->digitTransformTable();
3116                 $digitTransTable = $digitTransTable ?: [];
3117                 $compactDigitTransTable = [
3118                         implode( "\t", array_keys( $digitTransTable ) ),
3119                         implode( "\t", $digitTransTable ),
3120                 ];
3121
3122                 $user = $this->getUser();
3123
3124                 $vars = [
3125                         'wgCanonicalNamespace' => $canonicalNamespace,
3126                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3127                         'wgNamespaceNumber' => $title->getNamespace(),
3128                         'wgPageName' => $title->getPrefixedDBkey(),
3129                         'wgTitle' => $title->getText(),
3130                         'wgCurRevisionId' => $curRevisionId,
3131                         'wgRevisionId' => (int)$this->getRevisionId(),
3132                         'wgArticleId' => $articleId,
3133                         'wgIsArticle' => $this->isArticle(),
3134                         'wgIsRedirect' => $title->isRedirect(),
3135                         'wgAction' => Action::getActionName( $this->getContext() ),
3136                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3137                         'wgUserGroups' => $user->getEffectiveGroups(),
3138                         'wgCategories' => $this->getCategories(),
3139                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3140                         'wgPageContentLanguage' => $lang->getCode(),
3141                         'wgPageContentModel' => $title->getContentModel(),
3142                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3143                         'wgDigitTransformTable' => $compactDigitTransTable,
3144                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3145                         'wgMonthNames' => $lang->getMonthNamesArray(),
3146                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3147                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3148                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3149                         'wgRequestId' => WebRequest::getRequestId(),
3150                 ];
3151
3152                 if ( $user->isLoggedIn() ) {
3153                         $vars['wgUserId'] = $user->getId();
3154                         $vars['wgUserEditCount'] = $user->getEditCount();
3155                         $userReg = $user->getRegistration();
3156                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3157                         // Get the revision ID of the oldest new message on the user's talk
3158                         // page. This can be used for constructing new message alerts on
3159                         // the client side.
3160                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3161                 }
3162
3163                 if ( $wgContLang->hasVariants() ) {
3164                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3165                 }
3166                 // Same test as SkinTemplate
3167                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3168                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3169
3170                 $vars['wgRelevantPageIsProbablyEditable'] = $relevantTitle
3171                         && $relevantTitle->quickUserCan( 'edit', $user )
3172                         && ( $relevantTitle->exists() || $relevantTitle->quickUserCan( 'create', $user ) );
3173
3174                 foreach ( $title->getRestrictionTypes() as $type ) {
3175                         // Following keys are set in $vars:
3176                         // wgRestrictionCreate, wgRestrictionEdit, wgRestrictionMove, wgRestrictionUpload
3177                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3178                 }
3179
3180                 if ( $title->isMainPage() ) {
3181                         $vars['wgIsMainPage'] = true;
3182                 }
3183
3184                 if ( $this->mRedirectedFrom ) {
3185                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3186                 }
3187
3188                 if ( $relevantUser ) {
3189                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3190                 }
3191
3192                 // Allow extensions to add their custom variables to the mw.config map.
3193                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3194                 // page-dependant but site-wide (without state).
3195                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3196                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3197
3198                 // Merge in variables from addJsConfigVars last
3199                 return array_merge( $vars, $this->getJsConfigVars() );
3200         }
3201
3202         /**
3203          * To make it harder for someone to slip a user a fake
3204          * JavaScript or CSS preview, a random token
3205          * is associated with the login session. If it's not
3206          * passed back with the preview request, we won't render
3207          * the code.
3208          *
3209          * @return bool
3210          */
3211         public function userCanPreview() {
3212                 $request = $this->getRequest();
3213                 if (
3214                         $request->getVal( 'action' ) !== 'submit' ||
3215                         !$request->wasPosted()
3216                 ) {
3217                         return false;
3218                 }
3219
3220                 $user = $this->getUser();
3221
3222                 if ( !$user->isLoggedIn() ) {
3223                         // Anons have predictable edit tokens
3224                         return false;
3225                 }
3226                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3227                         return false;
3228                 }
3229
3230                 $title = $this->getTitle();
3231                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3232                 if ( count( $errors ) !== 0 ) {
3233                         return false;
3234                 }
3235
3236                 return true;
3237         }
3238
3239         /**
3240          * @return array Array in format "link name or number => 'link html'".
3241          */
3242         public function getHeadLinksArray() {
3243                 global $wgVersion;
3244
3245                 $tags = [];
3246                 $config = $this->getConfig();
3247
3248                 $canonicalUrl = $this->mCanonicalUrl;
3249
3250                 $tags['meta-generator'] = Html::element( 'meta', [
3251                         'name' => 'generator',
3252                         'content' => "MediaWiki $wgVersion",
3253                 ] );
3254
3255                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3256                         // Per https://w3c.github.io/webappsec-referrer-policy/#unknown-policy-values
3257                         // fallbacks should come before the primary value so we need to reverse the array.
3258                         foreach ( array_reverse( (array)$config->get( 'ReferrerPolicy' ) ) as $i => $policy ) {
3259                                 $tags["meta-referrer-$i"] = Html::element( 'meta', [
3260                                         'name' => 'referrer',
3261                                         'content' => $policy,
3262                                 ] );
3263                         }
3264                 }
3265
3266                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3267                 if ( $p !== 'index,follow' ) {
3268                         // http://www.robotstxt.org/wc/meta-user.html
3269                         // Only show if it's different from the default robots policy
3270                         $tags['meta-robots'] = Html::element( 'meta', [
3271                                 'name' => 'robots',
3272                                 'content' => $p,
3273                         ] );
3274                 }
3275
3276                 foreach ( $this->mMetatags as $tag ) {
3277                         if ( strncasecmp( $tag[0], 'http:', 5 ) === 0 ) {
3278                                 $a = 'http-equiv';
3279                                 $tag[0] = substr( $tag[0], 5 );
3280                         } elseif ( strncasecmp( $tag[0], 'og:', 3 ) === 0 ) {
3281                                 $a = 'property';
3282                         } else {
3283                                 $a = 'name';
3284                         }
3285                         $tagName = "meta-{$tag[0]}";
3286                         if ( isset( $tags[$tagName] ) ) {
3287                                 $tagName .= $tag[1];
3288                         }
3289                         $tags[$tagName] = Html::element( 'meta',
3290                                 [
3291                                         $a => $tag[0],
3292                                         'content' => $tag[1]
3293                                 ]
3294                         );
3295                 }
3296
3297                 foreach ( $this->mLinktags as $tag ) {
3298                         $tags[] = Html::element( 'link', $tag );
3299                 }
3300
3301                 # Universal edit button
3302                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3303                         $user = $this->getUser();
3304                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3305                                 && ( $this->getTitle()->exists() ||
3306                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3307                         ) {
3308                                 // Original UniversalEditButton
3309                                 $msg = $this->msg( 'edit' )->text();
3310                                 $tags['universal-edit-button'] = Html::element( 'link', [
3311                                         'rel' => 'alternate',
3312                                         'type' => 'application/x-wiki',
3313                                         'title' => $msg,
3314                                         'href' => $this->getTitle()->getEditURL(),
3315                                 ] );
3316                                 // Alternate edit link
3317                                 $tags['alternative-edit'] = Html::element( 'link', [
3318                                         'rel' => 'edit',
3319                                         'title' => $msg,
3320                                         'href' => $this->getTitle()->getEditURL(),
3321                                 ] );
3322                         }
3323                 }
3324
3325                 # Generally the order of the favicon and apple-touch-icon links
3326                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3327                 # uses whichever one appears later in the HTML source. Make sure
3328                 # apple-touch-icon is specified first to avoid this.
3329                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3330                         $tags['apple-touch-icon'] = Html::element( 'link', [
3331                                 'rel' => 'apple-touch-icon',
3332                                 'href' => $config->get( 'AppleTouchIcon' )
3333                         ] );
3334                 }
3335
3336                 if ( $config->get( 'Favicon' ) !== false ) {
3337                         $tags['favicon'] = Html::element( 'link', [
3338                                 'rel' => 'shortcut icon',
3339                                 'href' => $config->get( 'Favicon' )
3340                         ] );
3341                 }
3342
3343                 # OpenSearch description link
3344                 $tags['opensearch'] = Html::element( 'link', [
3345                         'rel' => 'search',
3346                         'type' => 'application/opensearchdescription+xml',
3347                         'href' => wfScript( 'opensearch_desc' ),
3348                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3349                 ] );
3350
3351                 # Real Simple Discovery link, provides auto-discovery information
3352                 # for the MediaWiki API (and potentially additional custom API
3353                 # support such as WordPress or Twitter-compatible APIs for a
3354                 # blogging extension, etc)
3355                 $tags['rsd'] = Html::element( 'link', [
3356                         'rel' => 'EditURI',
3357                         'type' => 'application/rsd+xml',
3358                         // Output a protocol-relative URL here if $wgServer is protocol-relative.
3359                         // Whether RSD accepts relative or protocol-relative URLs is completely
3360                         // undocumented, though.
3361                         'href' => wfExpandUrl( wfAppendQuery(
3362                                 wfScript( 'api' ),
3363                                 [ 'action' => 'rsd' ] ),
3364                                 PROTO_RELATIVE
3365                         ),
3366                 ] );
3367
3368                 # Language variants
3369                 if ( !$config->get( 'DisableLangConversion' ) ) {
3370                         $lang = $this->getTitle()->getPageLanguage();
3371                         if ( $lang->hasVariants() ) {
3372                                 $variants = $lang->getVariants();
3373                                 foreach ( $variants as $variant ) {
3374                                         $tags["variant-$variant"] = Html::element( 'link', [
3375                                                 'rel' => 'alternate',
3376                                                 'hreflang' => LanguageCode::bcp47( $variant ),
3377                                                 'href' => $this->getTitle()->getLocalURL(
3378                                                         [ 'variant' => $variant ] )
3379                                                 ]
3380                                         );
3381                                 }
3382                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3383                                 $tags["variant-x-default"] = Html::element( 'link', [
3384                                         'rel' => 'alternate',
3385                                         'hreflang' => 'x-default',
3386                                         'href' => $this->getTitle()->getLocalURL() ] );
3387                         }
3388                 }
3389
3390                 # Copyright
3391                 if ( $this->copyrightUrl !== null ) {
3392                         $copyright = $this->copyrightUrl;
3393                 } else {
3394                         $copyright = '';
3395                         if ( $config->get( 'RightsPage' ) ) {
3396                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3397
3398                                 if ( $copy ) {
3399                                         $copyright = $copy->getLocalURL();
3400                                 }
3401                         }
3402
3403                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3404                                 $copyright = $config->get( 'RightsUrl' );
3405                         }
3406                 }
3407
3408                 if ( $copyright ) {
3409                         $tags['copyright'] = Html::element( 'link', [
3410                                 'rel' => 'license',
3411                                 'href' => $copyright ]
3412                         );
3413                 }
3414
3415                 # Feeds
3416                 if ( $config->get( 'Feed' ) ) {
3417                         $feedLinks = [];
3418
3419                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3420                                 # Use the page name for the title.  In principle, this could
3421                                 # lead to issues with having the same name for different feeds
3422                                 # corresponding to the same page, but we can't avoid that at
3423                                 # this low a level.
3424
3425                                 $feedLinks[] = $this->feedLink(
3426                                         $format,
3427                                         $link,
3428                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3429                                         $this->msg(
3430                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3431                                         )->text()
3432                                 );
3433                         }
3434
3435                         # Recent changes feed should appear on every page (except recentchanges,
3436                         # that would be redundant). Put it after the per-page feed to avoid
3437                         # changing existing behavior. It's still available, probably via a
3438                         # menu in your browser. Some sites might have a different feed they'd
3439                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3440                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3441                         # If so, use it instead.
3442                         $sitename = $config->get( 'Sitename' );
3443                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3444                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3445                                         // Note, this->feedLink escapes the url.
3446                                         $feedLinks[] = $this->feedLink(
3447                                                 $type,
3448                                                 $feedUrl,
3449                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3450                                         );
3451                                 }
3452                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3453                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3454                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3455                                         $feedLinks[] = $this->feedLink(
3456                                                 $format,
3457                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3458                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3459                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3460                                         );
3461                                 }
3462                         }
3463
3464                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3465                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3466                         # use OutputPage::addFeedLink() instead.
3467                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3468
3469                         $tags += $feedLinks;
3470                 }
3471
3472                 # Canonical URL
3473                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3474                         if ( $canonicalUrl !== false ) {
3475                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3476                         } else {
3477                                 if ( $this->isArticleRelated() ) {
3478                                         // This affects all requests where "setArticleRelated" is true. This is
3479                                         // typically all requests that show content (query title, curid, oldid, diff),
3480                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3481                                         // It does not apply to File pages and Special pages.
3482                                         // 'history' and 'info' actions address page metadata rather than the page
3483                                         // content itself, so they may not be canonicalized to the view page url.
3484                                         // TODO: this ought to be better encapsulated in the Action class.
3485                                         $action = Action::getActionName( $this->getContext() );
3486                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3487                                                 $query = "action={$action}";
3488                                         } else {
3489                                                 $query = '';
3490                                         }
3491                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3492                                 } else {
3493                                         $reqUrl = $this->getRequest()->getRequestURL();
3494                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3495                                 }
3496                         }
3497                 }
3498                 if ( $canonicalUrl !== false ) {
3499                         $tags[] = Html::element( 'link', [
3500                                 'rel' => 'canonical',
3501                                 'href' => $canonicalUrl
3502                         ] );
3503                 }
3504
3505                 return $tags;
3506         }
3507
3508         /**
3509          * Generate a "<link rel/>" for a feed.
3510          *
3511          * @param string $type Feed type
3512          * @param string $url URL to the feed
3513          * @param string $text Value of the "title" attribute
3514          * @return string HTML fragment
3515          */
3516         private function feedLink( $type, $url, $text ) {
3517                 return Html::element( 'link', [
3518                         'rel' => 'alternate',
3519                         'type' => "application/$type+xml",
3520                         'title' => $text,
3521                         'href' => $url ]
3522                 );
3523         }
3524
3525         /**
3526          * Add a local or specified stylesheet, with the given media options.
3527          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3528          *
3529          * @param string $style URL to the file
3530          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3531          * @param string $condition For IE conditional comments, specifying an IE version
3532          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3533          */
3534         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3535                 $options = [];
3536                 if ( $media ) {
3537                         $options['media'] = $media;
3538                 }
3539                 if ( $condition ) {
3540                         $options['condition'] = $condition;
3541                 }
3542                 if ( $dir ) {
3543                         $options['dir'] = $dir;
3544                 }
3545                 $this->styles[$style] = $options;
3546         }
3547
3548         /**
3549          * Adds inline CSS styles
3550          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3551          *
3552          * @param mixed $style_css Inline CSS
3553          * @param string $flip Set to 'flip' to flip the CSS if needed
3554          */
3555         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3556                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3557                         # If wanted, and the interface is right-to-left, flip the CSS
3558                         $style_css = CSSJanus::transform( $style_css, true, false );
3559                 }
3560                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3561         }
3562
3563         /**
3564          * Build exempt modules and legacy non-ResourceLoader styles.
3565          *
3566          * @return string|WrappedStringList HTML
3567          */
3568         protected function buildExemptModules() {
3569                 $chunks = [];
3570                 // Things that go after the ResourceLoaderDynamicStyles marker
3571                 $append = [];
3572
3573                 // We want site, private and user styles to override dynamically added styles from
3574                 // general modules, but we want dynamically added styles to override statically added
3575                 // style modules. So the order has to be:
3576                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3577                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3578                 // - ResourceLoaderDynamicStyles marker
3579                 // - site/private/user styles
3580
3581                 // Add legacy styles added through addStyle()/addInlineStyle() here
3582                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3583
3584                 $chunks[] = Html::element(
3585                         'meta',
3586                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3587                 );
3588
3589                 $separateReq = [ 'site.styles', 'user.styles' ];
3590                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3591                         // Combinable modules
3592                         $chunks[] = $this->makeResourceLoaderLink(
3593                                 array_diff( $moduleNames, $separateReq ),
3594                                 ResourceLoaderModule::TYPE_STYLES
3595                         );
3596
3597                         foreach ( array_intersect( $moduleNames, $separateReq ) as $name ) {
3598                                 // These require their own dedicated request in order to support "@import"
3599                                 // syntax, which is incompatible with concatenation. (T147667, T37562)
3600                                 $chunks[] = $this->makeResourceLoaderLink( $name,
3601                                         ResourceLoaderModule::TYPE_STYLES
3602                                 );
3603                         }
3604                 }
3605
3606                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3607         }
3608
3609         /**
3610          * @return array
3611          */
3612         public function buildCssLinksArray() {
3613                 $links = [];
3614
3615                 foreach ( $this->styles as $file => $options ) {
3616                         $link = $this->styleLink( $file, $options );
3617                         if ( $link ) {
3618                                 $links[$file] = $link;
3619                         }
3620                 }
3621                 return $links;
3622         }
3623
3624         /**
3625          * Generate \<link\> tags for stylesheets
3626          *
3627          * @param string $style URL to the file
3628          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3629          * @return string HTML fragment
3630          */
3631         protected function styleLink( $style, array $options ) {
3632                 if ( isset( $options['dir'] ) ) {
3633                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3634                                 return '';
3635                         }
3636                 }
3637
3638                 if ( isset( $options['media'] ) ) {
3639                         $media = self::transformCssMedia( $options['media'] );
3640                         if ( is_null( $media ) ) {
3641                                 return '';
3642                         }
3643                 } else {
3644                         $media = 'all';
3645                 }
3646
3647                 if ( substr( $style, 0, 1 ) == '/' ||
3648                         substr( $style, 0, 5 ) == 'http:' ||
3649                         substr( $style, 0, 6 ) == 'https:' ) {
3650                         $url = $style;
3651                 } else {
3652                         $config = $this->getConfig();
3653                         // Append file hash as query parameter
3654                         $url = self::transformResourcePath(
3655                                 $config,
3656                                 $config->get( 'StylePath' ) . '/' . $style
3657                         );
3658                 }
3659
3660                 $link = Html::linkedStyle( $url, $media );
3661
3662                 if ( isset( $options['condition'] ) ) {
3663                         $condition = htmlspecialchars( $options['condition'] );
3664                         $link = "<!--[if $condition]>$link<![endif]-->";
3665                 }
3666                 return $link;
3667         }
3668
3669         /**
3670          * Transform path to web-accessible static resource.
3671          *
3672          * This is used to add a validation hash as query string.
3673          * This aids various behaviors:
3674          *
3675          * - Put long Cache-Control max-age headers on responses for improved
3676          *   cache performance.
3677          * - Get the correct version of a file as expected by the current page.
3678          * - Instantly get the updated version of a file after deployment.
3679          *
3680          * Avoid using this for urls included in HTML as otherwise clients may get different
3681          * versions of a resource when navigating the site depending on when the page was cached.
3682          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3683          * an external stylesheet).
3684          *
3685          * @since 1.27
3686          * @param Config $config
3687          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3688          * @return string URL
3689          */
3690         public static function transformResourcePath( Config $config, $path ) {
3691                 global $IP;
3692
3693                 $localDir = $IP;
3694                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3695                 if ( $remotePathPrefix === '' ) {
3696                         // The configured base path is required to be empty string for
3697                         // wikis in the domain root
3698                         $remotePath = '/';
3699                 } else {
3700                         $remotePath = $remotePathPrefix;
3701                 }
3702                 if ( strpos( $path, $remotePath ) !== 0 || substr( $path, 0, 2 ) === '//' ) {
3703                         // - Path is outside wgResourceBasePath, ignore.
3704                         // - Path is protocol-relative. Fixes T155310. Not supported by RelPath lib.
3705                         return $path;
3706                 }
3707                 // For files in resources, extensions/ or skins/, ResourceBasePath is preferred here.
3708                 // For other misc files in $IP, we'll fallback to that as well. There is, however, a fourth
3709                 // supported dir/path pair in the configuration (wgUploadDirectory, wgUploadPath)
3710                 // which is not expected to be in wgResourceBasePath on CDNs. (T155146)
3711                 $uploadPath = $config->get( 'UploadPath' );
3712                 if ( strpos( $path, $uploadPath ) === 0 ) {
3713                         $localDir = $config->get( 'UploadDirectory' );
3714                         $remotePathPrefix = $remotePath = $uploadPath;
3715                 }
3716
3717                 $path = RelPath::getRelativePath( $path, $remotePath );
3718                 return self::transformFilePath( $remotePathPrefix, $localDir, $path );
3719         }
3720
3721         /**
3722          * Utility method for transformResourceFilePath().
3723          *
3724          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3725          *
3726          * @since 1.27
3727          * @param string $remotePathPrefix URL path prefix that points to $localPath
3728          * @param string $localPath File directory exposed at $remotePath
3729          * @param string $file Path to target file relative to $localPath
3730          * @return string URL
3731          */
3732         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3733                 $hash = md5_file( "$localPath/$file" );
3734                 if ( $hash === false ) {
3735                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3736                         $hash = '';
3737                 }
3738                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3739         }
3740
3741         /**
3742          * Transform "media" attribute based on request parameters
3743          *
3744          * @param string $media Current value of the "media" attribute
3745          * @return string Modified value of the "media" attribute, or null to skip
3746          * this stylesheet
3747          */
3748         public static function transformCssMedia( $media ) {
3749                 global $wgRequest;
3750
3751                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3752                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3753
3754                 // Switch in on-screen display for media testing
3755                 $switches = [
3756                         'printable' => 'print',
3757                         'handheld' => 'handheld',
3758                 ];
3759                 foreach ( $switches as $switch => $targetMedia ) {
3760                         if ( $wgRequest->getBool( $switch ) ) {
3761                                 if ( $media == $targetMedia ) {
3762                                         $media = '';
3763                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3764                                         /* This regex will not attempt to understand a comma-separated media_query_list
3765                                          *
3766                                          * Example supported values for $media:
3767                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3768                                          * Example NOT supported value for $media:
3769                                          * '3d-glasses, screen, print and resolution > 90dpi'
3770                                          *
3771                                          * If it's a print request, we never want any kind of screen stylesheets
3772                                          * If it's a handheld request (currently the only other choice with a switch),
3773                                          * we don't want simple 'screen' but we might want screen queries that
3774                                          * have a max-width or something, so we'll pass all others on and let the
3775                                          * client do the query.
3776                                          */
3777                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3778                                                 return null;
3779                                         }
3780                                 }
3781                         }
3782                 }
3783
3784                 return $media;
3785         }
3786
3787         /**
3788          * Add a wikitext-formatted message to the output.
3789          * This is equivalent to:
3790          *
3791          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3792          */
3793         public function addWikiMsg( /*...*/ ) {
3794                 $args = func_get_args();
3795                 $name = array_shift( $args );
3796                 $this->addWikiMsgArray( $name, $args );
3797         }
3798
3799         /**
3800          * Add a wikitext-formatted message to the output.
3801          * Like addWikiMsg() except the parameters are taken as an array
3802          * instead of a variable argument list.
3803          *
3804          * @param string $name
3805          * @param array $args
3806          */
3807         public function addWikiMsgArray( $name, $args ) {
3808                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3809         }
3810
3811         /**
3812          * This function takes a number of message/argument specifications, wraps them in
3813          * some overall structure, and then parses the result and adds it to the output.
3814          *
3815          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3816          * and so on. The subsequent arguments may be either
3817          * 1) strings, in which case they are message names, or
3818          * 2) arrays, in which case, within each array, the first element is the message
3819          *    name, and subsequent elements are the parameters to that message.
3820          *
3821          * Don't use this for messages that are not in the user's interface language.
3822          *
3823          * For example:
3824          *
3825          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3826          *
3827          * Is equivalent to:
3828          *
3829          *    $wgOut->addWikiText( "<div class='error'>\n"
3830          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3831          *
3832          * The newline after the opening div is needed in some wikitext. See T21226.
3833          *
3834          * @param string $wrap
3835          */
3836         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3837                 $msgSpecs = func_get_args();
3838                 array_shift( $msgSpecs );
3839                 $msgSpecs = array_values( $msgSpecs );
3840                 $s = $wrap;
3841                 foreach ( $msgSpecs as $n => $spec ) {
3842                         if ( is_array( $spec ) ) {
3843                                 $args = $spec;
3844                                 $name = array_shift( $args );
3845                                 if ( isset( $args['options'] ) ) {
3846                                         unset( $args['options'] );
3847                                         wfDeprecated(
3848                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3849                                                 '1.20'
3850                                         );
3851                                 }
3852                         } else {
3853                                 $args = [];
3854                                 $name = $spec;
3855                         }
3856                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3857                 }
3858                 $this->addWikiText( $s );
3859         }
3860
3861         /**
3862          * Whether the output has a table of contents
3863          * @return bool
3864          * @since 1.22
3865          */
3866         public function isTOCEnabled() {
3867                 return $this->mEnableTOC;
3868         }
3869
3870         /**
3871          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3872          * @param bool $flag
3873          * @since 1.23
3874          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3875          */
3876         public function enableSectionEditLinks( $flag = true ) {
3877                 wfDeprecated( __METHOD__, '1.31' );
3878         }
3879
3880         /**
3881          * @return bool
3882          * @since 1.23
3883          * @deprecated since 1.31, use $poOptions to addParserOutput() instead.
3884          */
3885         public function sectionEditLinksEnabled() {
3886                 wfDeprecated( __METHOD__, '1.31' );
3887                 return true;
3888         }
3889
3890         /**
3891          * Helper function to setup the PHP implementation of OOUI to use in this request.
3892          *
3893          * @since 1.26
3894          * @param String $skinName The Skin name to determine the correct OOUI theme
3895          * @param String $dir Language direction
3896          */
3897         public static function setupOOUI( $skinName = 'default', $dir = 'ltr' ) {
3898                 $themes = ResourceLoaderOOUIModule::getSkinThemeMap();
3899                 $theme = $themes[$skinName] ?? $themes['default'];
3900                 // For example, 'OOUI\WikimediaUITheme'.
3901                 $themeClass = "OOUI\\{$theme}Theme";
3902                 OOUI\Theme::setSingleton( new $themeClass() );
3903                 OOUI\Element::setDefaultDir( $dir );
3904         }
3905
3906         /**
3907          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3908          * MediaWiki and this OutputPage instance.
3909          *
3910          * @since 1.25
3911          */
3912         public function enableOOUI() {
3913                 self::setupOOUI(
3914                         strtolower( $this->getSkin()->getSkinName() ),
3915                         $this->getLanguage()->getDir()
3916                 );
3917                 $this->addModuleStyles( [
3918                         'oojs-ui-core.styles',
3919                         'oojs-ui.styles.indicators',
3920                         'oojs-ui.styles.textures',
3921                         'mediawiki.widgets.styles',
3922                         'oojs-ui.styles.icons-content',
3923                         'oojs-ui.styles.icons-alerts',
3924                         'oojs-ui.styles.icons-interactions',
3925                 ] );
3926         }
3927
3928         /**
3929          * Add Link headers for preloading the wiki's logo.
3930          *
3931          * @since 1.26
3932          */
3933         protected function addLogoPreloadLinkHeaders() {
3934                 $logo = ResourceLoaderSkinModule::getLogo( $this->getConfig() );
3935
3936                 $tags = [];
3937                 $logosPerDppx = [];
3938                 $logos = [];
3939
3940                 if ( !is_array( $logo ) ) {
3941                         // No media queries required if we only have one variant
3942                         $this->addLinkHeader( '<' . $logo . '>;rel=preload;as=image' );
3943                         return;
3944                 }
3945
3946                 if ( isset( $logo['svg'] ) ) {
3947                         // No media queries required if we only have a 1x and svg variant
3948                         // because all preload-capable browsers support SVGs
3949                         $this->addLinkHeader( '<' . $logo['svg'] . '>;rel=preload;as=image' );
3950                         return;
3951                 }
3952
3953                 foreach ( $logo as $dppx => $src ) {
3954                         // Keys are in this format: "1.5x"
3955                         $dppx = substr( $dppx, 0, -1 );
3956                         $logosPerDppx[$dppx] = $src;
3957                 }
3958
3959                 // Because PHP can't have floats as array keys
3960                 uksort( $logosPerDppx, function ( $a , $b ) {
3961                         $a = floatval( $a );
3962                         $b = floatval( $b );
3963                         // Sort from smallest to largest (e.g. 1x, 1.5x, 2x)
3964                         return $a <=> $b;
3965                 } );
3966
3967                 foreach ( $logosPerDppx as $dppx => $src ) {
3968                         $logos[] = [ 'dppx' => $dppx, 'src' => $src ];
3969                 }
3970
3971                 $logosCount = count( $logos );
3972                 // Logic must match ResourceLoaderSkinModule:
3973                 // - 1x applies to resolution < 1.5dppx
3974                 // - 1.5x applies to resolution >= 1.5dppx && < 2dppx
3975                 // - 2x applies to resolution >= 2dppx
3976                 // Note that min-resolution and max-resolution are both inclusive.
3977                 for ( $i = 0; $i < $logosCount; $i++ ) {
3978                         if ( $i === 0 ) {
3979                                 // Smallest dppx
3980                                 // min-resolution is ">=" (larger than or equal to)
3981                                 // "not min-resolution" is essentially "<"
3982                                 $media_query = 'not all and (min-resolution: ' . $logos[ 1 ]['dppx'] . 'dppx)';
3983                         } elseif ( $i !== $logosCount - 1 ) {
3984                                 // In between
3985                                 // Media query expressions can only apply "not" to the entire expression
3986                                 // (e.g. can't express ">= 1.5 and not >= 2).
3987                                 // Workaround: Use <= 1.9999 in place of < 2.
3988                                 $upper_bound = floatval( $logos[ $i + 1 ]['dppx'] ) - 0.000001;
3989                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] .
3990                                         'dppx) and (max-resolution: ' . $upper_bound . 'dppx)';
3991                         } else {
3992                                 // Largest dppx
3993                                 $media_query = '(min-resolution: ' . $logos[ $i ]['dppx'] . 'dppx)';
3994                         }
3995
3996                         $this->addLinkHeader(
3997                                 '<' . $logos[$i]['src'] . '>;rel=preload;as=image;media=' . $media_query
3998                         );
3999                 }
4000         }
4001
4002         /**
4003          * Get (and set if not yet set) the CSP nonce.
4004          *
4005          * This value needs to be included in any <script> tags on the
4006          * page.
4007          *
4008          * @return string|bool Nonce or false to mean don't output nonce
4009          * @since 1.32
4010          */
4011         public function getCSPNonce() {
4012                 if ( !ContentSecurityPolicy::isEnabled( $this->getConfig() ) ) {
4013                         return false;
4014                 }
4015                 if ( $this->CSPNonce === null ) {
4016                         // XXX It might be expensive to generate randomness
4017                         // on every request, on Windows.
4018                         $rand = random_bytes( 15 );
4019                         $this->CSPNonce = base64_encode( $rand );
4020                 }
4021                 return $this->CSPNonce;
4022         }
4023 }